Evaluation of chemical enhancement on phytoremediation effect of Cd-contaminated soils with Calendula officinalis L.

PubMed

Liu, Jianv; Zhou, Qixing; Wang, Song

2010-07-01

The popular ornamental plant Calendula officinalis L was studied for its potential application in the phytoremediation of cadmium (Cd)-contaminated soils. Enhancements to the Cd accumulation by the application of sodium dodecyl sulfate (SDS), ethylenediaminetriacetic acid (EDTA) and ethylenegluatarotriacetic acid (EGTA) to the soil were investigated. Under these chemically enhanced treatments, EDTA was observed to be toxic to the plants leading to retarded growth. However, the application of SDS and/or EGTA was shown to result in significantly increased plant biomass (p < 0.05). Most of the chemical treatments resulted in increases to the shoot and root Cd concentrations, with the root Cd concentration being consistently higher than that shoot Cd concentration. Almost all of the investigated chemical treatments containing SDS or and EGTA were shown to lead to an increase in the total Cd content in the plants (p < 0.05). The application of EGTA alone led to an observed total Cd increase of up to 217%. This investigation revealed considerable efficiency of chemical enhancement and correspondingly increased potential of Calendula officinalis L. for applications of phytoremediation of Cd-contaminated sites.

Screening of a new cadmium hyperaccumulator, Galinsoga parviflora, from winter farmland weeds using the artificially high soil cadmium concentration method.

PubMed

Lin, Lijin; Jin, Qian; Liu, Yingjie; Ning, Bo; Liao, Ming'an; Luo, Li

2014-11-01

A new method, the artificially high soil cadmium (Cd) concentration method, was used to screen for Cd hyperaccumulators among winter farmland weeds. Galinsoga parviflora was the most promising remedial plant among 5 Cd accumulators or hyperaccumulators. In Cd concentration gradient experiments, as soil Cd concentration increased, root and shoot biomass decreased, and their Cd contents increased. In additional concentration gradient experiments, superoxide dismutase and peroxidase activities increased with soil Cd concentrations up to 75 mg kg(-1) , while expression of their isoenzymes strengthened. Catalase (CAT) activity declined and CAT isoenzyme expression weakened at soil Cd concentrations less than 50 mg kg(-1) . The maxima of Cd contents in shoots and roots were 137.63 mg kg(-1) and 105.70 mg kg(-1) , respectively, at 100 mg kg(-1) Cd in soil. The root and shoot bioconcentration factors exceeded 1.0, as did the translocation factor. In a field experiment, total extraction of Cd by shoots was 1.35 mg m(-2) to 1.43 mg m(-2) at soil Cd levels of 2.04 mg kg(-1) to 2.89 mg kg(-1) . Therefore, the artificially high soil Cd concentration method was effective for screening Cd hyperaccumulators. Galinsoga parviflora is a Cd hyperaccumulator that could be used to efficiently remediate Cd-contaminated farmland soil. © 2014 SETAC.

Cadmium-induced changes in pigments, total phenolics, and phenylalanine ammonia-lyase activity in fronds of Azolla imbricata.

PubMed

Dai, Ling-Peng; Xiong, Zhi-Ting; Huang, Yu; Li, Min-Jing

2006-10-01

This study was designed to examine the effects of cadmium on several color-related parameters (including chlorophyll, carotenoid, and anthocyanin), total phenolics, and phenylalanine ammonia-lyase (PAL) activity in an aquatic fern species Azolla imbricate (A. imbricata). Cd accumulation and effects in the fronds were closely related with Cd concentration in the growth medium. The fronds under 0.5 mg/L Cd treatment turned red on the 3rd day, and this color change also appeared under 0.05 and 0.1 mg/L Cd treatment on the 5th day. Correlated with the color change, the contents of chlorophyll and carotenoid in the fronds significantly decreased in the presence of high Cd concentrations, while the anthocyanin content increased during the experiment. Significant increase in total phenolics content and PAL activity were also detected during Cd treatment. The results suggested that the Cd-induced change in color of fronds might be due to the decrease in chlorophyll and carotenoid and the increase in anthocyanin. Anthocyanin, total phenolics and their biosynthesis-related PAL might play a role in detoxification of Cd in A. imbricata.

Measurement of metal bioaccessibility in vegetables to improve human exposure assessments: field study of soil-plant-atmosphere transfers in urban areas, South China.

PubMed

Xiong, TianTian; Dumat, Camille; Pierart, Antoine; Shahid, Muhammad; Kang, Yuan; Li, Ning; Bertoni, Georges; Laplanche, Christophe

2016-12-01

The quality of cultivated consumed vegetables in relation to environmental pollution is a crucial issue for urban and peri-urban areas, which host the majority of people at the global scale. In order to evaluate the fate of metals in urban soil-plant-atmosphere systems and their consequences on human exposure, a field study was conducted at two different sites near a waste incinerator (site A) and a highway (site B). Metal concentrations were measured in the soil, settled atmospheric particulate matter (PM) and vegetables. A risk assessment was performed using both total and bioaccessible metal concentrations in vegetables. Total metal concentrations in PM were (mg kg -1 ): (site A) 417 Cr, 354 Cu, 931 Zn, 6.3 Cd and 168 Pb; (site B) 145 Cr, 444 Cu, 3289 Zn, 2.9 Cd and 396 Pb. Several total soil Cd and Pb concentrations exceeded China's Environmental Quality Standards. At both sites, there was significant metal enrichment from the atmosphere to the leafy vegetables (correlation between Pb concentrations in PM and leaves: r = 0.52, p < 0.05) which depended on the plant species. Total Cr, Cd and Pb concentrations in vegetables were therefore above or just under the maximum limit levels for foodstuffs according to Chinese and European Commission regulations. High metal bioaccessibility in the vegetables (60-79 %, with maximum value for Cd) was also observed. The bioaccessible hazard index was only above 1 for site B, due to moderate Pb and Cd pollution from the highway. In contrast, site A was considered as relatively safe for urban agriculture.

Elevated atmospheric CO2 affected photosynthetic products in wheat seedlings and biological activity in rhizosphere soil under cadmium stress.

PubMed

Jia, Xia; Liu, Tuo; Zhao, Yonghua; He, Yunhua; Yang, Mingyan

2016-01-01

The objective of this study was to investigate the effects of elevated CO2 (700 ± 23 μmol mol(-1)) on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated CO2 was associated with decreased quantities of reducing sugars, starch, and soluble amino acids, and with increased quantities of soluble sugars, total sugars, and soluble proteins in wheat seedlings under Cd stress. The contents of total soluble sugars, total free amino acids, total soluble phenolic acids, and total organic acids in the rhizosphere soil under Cd stress were improved by elevated CO2. Compared to Cd stress alone, the activity of amylase, phenol oxidase, urease, L-asparaginase, β-glucosidase, neutral phosphatase, and fluorescein diacetate increased under elevated CO2 in combination with Cd stress; only cellulase activity decreased. Bacterial abundance in rhizosphere soil was stimulated by elevated CO2 at low Cd concentrations (1.31-5.31 mg Cd kg(-1) dry soil). Actinomycetes, total microbial abundance, and fungi decreased under the combined conditions at 5.31-10.31 mg Cd kg(-1) dry soil. In conclusion, increased production of soluble sugars, total sugars, and proteins in wheat seedlings under elevated CO2 + Cd stress led to greater quantities of organic compounds in the rhizosphere soil relative to seedlings grown under Cd stress only. Elevated CO2 concentrations could moderate the effects of heavy metal pollution on enzyme activity and microorganism abundance in rhizosphere soils, thus improving soil fertility and the microecological rhizosphere environment of wheat under Cd stress.

Relationship among circulating anti-Müllerian hormone, insulin like growth factor 1, cadmium and superovulatory response in dairy cows.

PubMed

Abdel Aziz, R L; Khalil, A A Y; Abdel-Wahab, A; Hassan, N Y; Abdel-Hamied, E; Kasimanickam, R K

2017-09-15

The objectives of this study were 1. to determine the associations among circulating anti-Mullerian hormone (AMH), insulin like growth factor 1 (IGF1) and cadmium (Cd) concentrations of lactating Holstein cows at the time of superovulation and 2. to determine the effect of circulating AMH, IGF1 and Cd concentrations on the superovulatory response in Holstein dairy cows. Holstein cows (n = 30) were milked thrice daily and housed and fed in free stall barn as a separate group. All animals were synchronized for superovulation and flushed. Three blood samples for AMH, IGF1 and Cd analysis were collected prior to superovulation, at estrus and at the time of embryo collection. The concentrations of blood makers prior to superovulation were highly correlated to superovulatory response. Circulating concentrations of AMH, IGF1 prior to superovulation were negatively correlated to Cd concentrations (P < 0.05). There was no correlation between circulating concentrations of AMH and IGF1. The number of corpus luteum (r = 0.71), total embryo (r = 0.67), total transferable embryo (r = 0.51) and total grade 1 embryo (r = 0.5) were positively correlated to AMH concentrations (P < 0.05). There was a trend for negative correlation found between circulating cadmium concentrations and total grade 1 embryo yield (P < 0.1). When cows were classified into quartiles (Q) of circulating AMH concentration, number of corpus luteum, and total embryos, total transferable embryos and total grade 1 embryos yield was significantly different for AMH quartiles. The superovulatory response parameters evaluated were increased with increased AMH concentrations; particularly we observed a >2-fold difference between first and fourth AMH quartiles in total transferable embryo yield and total grade 1 embryo yield. In conclusion, circulating AMH concentration was strongly associated with superovulatory response. Measuring AMH before enrolling cows in superovulation programs will likely allow practitioners to improve numbers of embryos produced and, thereby, reduce costs per embryo produced. Published by Elsevier Inc.

Distribution and bioavailability of cadmium in ornithogenic coral-sand sediments of the Xisha archipelago, South China Sea.

PubMed

Liu, Xiaodong; Lou, Chuangneng; Xu, Liqiang; Sun, Liguang

2012-09-01

Total cadmium (Cd) concentrations in four ornithogenic coral-sand sedimentary profiles displayed a strong positive correlation with guano-derived phosphorus, but had no correlation with plant-originated organic matter in the top sediments. These results indicate that the total Cd distributions were predominantly controlled by guano input. Bioavailable Cd and zinc (Zn) had a greater input rate in the top sediments with respect to total Cd and total Zn, and a positive correlation with total organic carbon (TOC) derived from plant humus. Multi-regression analysis showed that the total Cd and TOC explained over 80% of the variation of bioavailable Cd, suggesting that both guano and plant inputs could significantly influence the distribution of bioavailable Cd, and that plant biocycling processes contribute more to the recent increase of bioavailable Cd. A pollution assessment indicates that the Yongle archipelago is moderately to strongly polluted with guano-derived Cd. Copyright © 2012 Elsevier Ltd. All rights reserved.

Subcellular partitioning of cadmium and zinc in mealworm beetle (Tenebrio molitor) larvae exposed to metal-contaminated flour.

PubMed

Bednarska, Agnieszka J; Świątek, Zuzanna

2016-11-01

By studying the internal compartmentalization of metals in different subcellular fractions we are able to better understand the mechanisms of metal accumulation in organisms and the transfer of metals through trophic chains. We investigated the internal compartmentalization of cadmium (Cd) and zinc (Zn) in mealworm beetle (Tenebrio molitor) larvae by breeding them in flour contaminated with either Cd at 100, 300 and 600mgkg(-1), or Zn at 1000 and 2000mgkg(-1). We separated the cellular components of the larvae into 3 fractions: the S1 or cytosolic fraction containing organelles, heat-sensitive and heat-stable proteins, the S2 or cellular debris fraction and the G or metal-rich granule fraction. The concentration of Cd and Zn in each fraction was measured at 0, 7, 14 and 21 days of being fed the flour. The concentration of Cd in the flour affected the concentration of Cd measured in each larval subcellular fraction (p≤0.0001), while the concentration of Zn in the flour only affected the Zn concentration in the S2 and G fractions (p≤0.02). Both Cd and Zn concentrations in mealworms remained relatively constant during the exposure (days 7, 14 and 21) in all three fractions, but the Cd concentrations were much higher than those found in larvae before the exposure (day 0). The concentration of Cd in the flour, however, did not affect the percentage of Cd in the S1 fraction. The contribution of Cd in the G fraction to the total Cd amount was similar (30-40%) in all Cd treatments. The percentage of Zn in all three fractions was not affected by the concentration of Zn in the flour and the relative contributions of each subcellular fraction to the total burden of Zn remained generally constant for both control and treated larvae. In general, larvae sequestered approximately 30% of Cd and Zn in the S1 fraction, which is important for the transport of metals to higher trophic levels in a food web. Copyright © 2016 Elsevier Inc. All rights reserved.

Partition coefficient of cadmium between organic soils and bean and oat plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddqui, M.F.R.; Courchesne, F.; Kennedy, G.

Environmental fate models require the partition coefficient data of contaminants among two or more environmental compartments. The bioaccumulation of cadmium (Cd) by bean and oat plants grown on organic soils in a controlled growth chamber was investigated to validate the plant/soil partition coefficient. Total Cd was measured in the soils and in the different parts of the plants. The mean total Cd concentrations for soil cultivated with beans and oats were 0.86 and 0.69 {micro}g/g, respectively. Selective extractants (BaCl{sub 2}, Na-pyrophosphate and HNO{sub 3}-hydroxy) were used to evaluate solid phase Cd species in the soil. In the soil cultivated withmore » bean, BaCl{sub 2} exchangeable, Na-pyrophosphate extractable and HNO{sub 3}-NH{sub 2}OH extractable Cd represented 1.2, 1.6 and 50.9% of total soil Cd, respectively. For the soil cultivated with oats, the same extractants gave values of 1.1, 1.8 and 61.9%. Cd concentration levels in bean plants followed the sequence roots > fruits = stems > leaves (p < 0.01) while the following sequence was observed for oat plants: roots > fruits > stems > leaves (p < 0.05). The partition coefficient for total Cd (Cd{sub Plant tissue}/Cd{sub Soil}) was in the range of 0.28--0.55 for bean plants and 1.03--1.86 for oat plants.« less

Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador.

PubMed

Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R S; Li, Y C; Moyano, B; Baligar, V C

2015-11-15

Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg(-1)) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0-5, 5-15, 15-30, and 30-50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg(-1), respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg(-1). Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg(-1)), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans>shell>leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg(-1), and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0-5 and 5-15 cm depths (r=0.80 and 0.82 for M3, and r=0.78 and 0.82 for HCl; P<0.01). These results indicate that accumulation of Cd in surface layers results in excessive Cd in cacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils. Copyright © 2015 Elsevier B.V. All rights reserved.

Phytoaccumulation and phytotoxicity of cadmium and chromium in duckweed Wolffia globosa.

PubMed

Boonyapookana, Benjaporn; Upatham, E Suchart; Kruatrachue, Maleeya; Pokethitiyook, Prayad; Singhakaew, Sombat

2002-01-01

The phytoaccumulation and phytotoxicity of heavy metals, cadmium (Cd), and chromium (Cr) on a common duckweed, Wolffia globosa, were studied. W. globosa were cultured in 3% Hoagland's nutrient medium, which was supplemented with 1, 2, 4, and 8 mg/L of Cd and Cr and were separately harvested after 3, 6, 9, and 12 days. The accumulation of Cd and Cr in W. globosa showed significant increases when the exposure time and metal concentration were increased. The effects of Cd and Cr on the biomass productivity and total chlorophyll content in W. globosa indicated that there were significant decreases in the biomass productivity and total chlorophyll content when the exposure time and metal concentration were increased.

Effects of environmental biomass-producing factors on Cd uptake in two Swedish ecotypes of Pinus sylvestris.

PubMed

Ekvall, Lars; Greger, Maria

2003-01-01

A factorial design was used to study direct effects of external biomass-producing factors such as light, temperature and photoperiod on cadmium (Cd) uptake and indirect effects, via change in biomass production in two ecotypes of Scots pine (Pinus silvestris). The aim was to find out if the external factors affect the Cd uptake directly or via change in biomass production, and if the effect differs between ecotypes. Seedlings were grown under 10 combinations of external factors, i.e. temperature (15 and 20 degrees C), light intensity (50 and 200 micromol photons m(-2) S(-1)), photoperiod (18 h light/8 h darkness and continuous light) and external Cd concentration (totally 1.88 and 7.50 micromol). The treatment lasted for 18 days and Cd concentrations in roots and shoots were determined by AAS. The results showed that an increased biomass production increased the total Cd uptake but had a dilution effect on the Cd concentration, especially in the root tissues. The external factors tested did not have any direct effects on the Cd untake, only in the case of Cd translocation to the shoot did the higher temperature show a direct increase, but only in the southern ecotype. The two ecotypes reacted differently in Cd uptake and translocation to the external factors studied. The relative Cd uptake creased with increasing photoperiod in the northern but not in the southern ecotype. The southern ecotype decreased the Cd concentration in the shoot with increased light intensity caused by a dilution effect due to extensive shoot growth of this ecotype. The conclusion is that the uptake in pine seedlings is mainly regulated via biomass production, and not directly by light and temperature and that resulting plant Cd contents to a certain extent depend on plant origin.

Population Pharmacokinetics of Cladribine in Patients with Multiple Sclerosis.

PubMed

Savic, Radojka M; Novakovic, Ana M; Ekblom, Marianne; Munafo, Alain; Karlsson, Mats O

2017-10-01

The aims of this study were to characterize the concentration-time course of cladribine (CdA) and its main metabolite 2-chloroadenine (CAde), estimate interindividual variability in pharmacokinetics (PK), and identify covariates explaining variability in the PK of CdA. This population PK analysis was based on the combined dataset from four clinical studies in patients with multiple sclerosis (MS): three phase I studies, including one food and one drug-drug interaction study, and one phase III clinical study. Plasma and urine concentration data of CdA and CAde were modeled simultaneously. The analysis comprised a total of 2619 CdA and CAde plasma and urine concentration observations from 173 patients with MS who received an intravenous infusion or oral tablet doses of CdA as a single agent or in combination with interferon (IFN) β-1a. CdA PK data were best described by a three-compartment model, while a one-compartment model best described the PK of CAde. CdA renal clearance (CL R ) was correlated with creatinine clearance (CL CR ), predicting a decrease in the total clearance of 19%, 30% and 40% for patients with mild (CL CR  = 65 ml/min), moderate (CL CR  = 40 ml/min) and severe (CL CR  = 20 ml/min) renal impairment, respectively. Food decreased the extent of CdA absorption by 11.2% and caused an absorption delay. Coadministration with IFNβ-1a was found to increase non-CL R (CL NR ) by 21%, resulting in an increase of 11% in total clearance. Both CdA and CAde displayed linear PK after intravenous and oral administration of CdA, with CdA renal function depending on CL CR . Trial registration number for study 25643: NCT00213135.

Effects of cadmium on cork oak (Quercus suber L.) plants grown in hydroponics.

PubMed

Gogorcena, Yolanda; Larbi, Ajmi; Andaluz, Sofia; Carpena, Ramón O; Abadía, Anunciación; Abadía, Javier

2011-12-01

Cork oak (Quercus suber L.) is an autochthonous tree species that is being used for reforestation in heavy-metal-contaminated areas in Spain. A hydroponics experiment was carried out to characterize the effects of Cd on several morphological and physiological parameters in this species, including shoot length, nutrient concentrations and allocation in different organs, leaf pigment concentrations, photosynthetic efficiency, root ferric chelate reductase (FCR) activity and organic acid concentrations in xylem sap. Four different Cd treatments were applied, adding Cd chelated with EDTA or as chloride salt at two different concentrations (10 and 50 µM Cd). After 1 month of Cd treatment, plant growth was significantly inhibited in all treatments. Results indicate that Cd accumulates in all organs 7- to 500-fold when compared with control plants. The highest Cd concentration was found in the 50 µM CdCl(2) treatment, which led to concentrations of ~30, 123 and 1153 µg Cd g(-1) dry weight in leaves, stems and roots, respectively. In the strongest Cd treatments the concentrations of P and Ca decreased in some plant parts, whereas the Mn leaf concentrations decreased with three of the four Cd treatments applied. The concentrations of chlorophyll and carotenoids on an area basis decreased, whereas the (zeaxanthin plus antheraxanthin)/(total violaxanthin cycle carotenoids) ratio and the non-photochemical quenching increased significantly in all Cd treatments. Cadmium treatments caused significant increases in the activity of the enzyme FCR in roots and in the concentrations of organic acids in xylem sap. Some of the physiological changes found support the fact that Cd induces a deficiency of Fe in cork oak, although the plant Fe concentrations were not reduced significantly. At higher concentrations the effects of Cd were more pronounced, and were more marked when Cd was in the free ion form than when present in the form of Cd-EDTA.

[Accumulation of S, Fe and Cd in rhizosphere of rice and their uptake in rice with different water managements].

PubMed

Zhang, Xue-Xia; Zhang, Xiao-Xia; Zheng, Yu-Ji; Wang, Rong-Ping; Chen, Neng-Chang; Lu, Pu-Xiang

2013-07-01

The interactions between the concentrations of sulfur, iron and cadmium in the rhizosphere and their uptakes in rice (Oryza sativa L. ) were studied using paddy soil which was contaminated by acid mine drainage under five water-management treatments of 60%, 80%, 100% field moisture capacity (FMC), flooded throughout the entire rice growth period and flooded followed by keeping 80% FMC after heading-flowering period. The water managements had no significant influence on the Fe and Cd concentrations in rhizosphere soil in maturity stage, although the concentration of Cd slightly increased with the increase of soil moisture in the tillering stage. However, the uptake of Fe and Cd in rice was obviously related to water managements. The increase of soil moisture enhanced the uptake of Fe, but decreased the uptake of Cd in different organs of rice (roots, stems and leaves, grains) except for Cd uptake of the root in the 60% FMC treatment. However, aerobic treatment after heading-flowering period enhanced Cd uptake in rice in all treatments, but did not influence the uptake of Fe in rice. On the other hand, the increase of soil moisture reduced the concentrations of total sulfur and available sulfur in the rhizosphere soil except for the 60% FMC treatment, which corresponded with the reduction of Cd uptake in rice. And the aerobic treatment promoted Cd uptake in rice, which was also positively related to the increase of total sulfur and available sulfur in rhizosphere soil. Therefore, it was concluded that the uptake and speciation of sulfur in rhizosphere soil other than the change of Fe concentration induced by water management could play an important role in Cd uptake of rice.

Effects of organic amendments on the toxicity and bioavailability of cadmium and copper in spiked formulated sediments

USGS Publications Warehouse

Besser, J.M.; Brumbaugh, W.G.; May, T.W.; Ingersoll, C.G.

2003-01-01

We evaluated the partitioning and toxicity of cadmium (Cd) and copper (Cu) spiked into formulated sediments containing two types of organic matter (OM), i.e., cellulose and humus. Amendments of cellulose up to 12.5% total organic carbon (TOC) did not affect partitioning of Cd or Cu between sediment and pore water and did not significantly affect the toxicity of spiked sediments in acute toxicity tests with the amphipod Hyalella azteca. In contrast, amendments of natural humus shifted the partitioning of both Cd and Cu toward greater concentrations in sediment and lesser concentrations in pore water and significantly reduced toxic effects of both metals. Thresholds for toxicity, based on measured metal concentrations in whole sediment, were greater for both Cd and Cu in sediments amended with a low level of humus (2.9% TOC) than in sediments without added OM. Amendments with a high level of humus (8.9% TOC) eliminated toxicity at the highest spike concentrations of both metals (sediment concentrations of 12.4 ??g Cd/g and 493 ??g Cu/g). Concentrations of Cd in pore water associated with acute toxicity were similar between sediments with and without humus amendments, suggesting that toxicity of Cd was reduced primarily by sorption to sediment OM. However, toxic effects of Cu in humus treatments were associated with greater pore-water concentrations than in controls, suggesting that toxicity of Cu was reduced both by sorption and by complexation with soluble ligands. Both sorption and complexation by OM tend to make proposed sediment quality guidelines (SQGs) based on total metal concentrations more protective for high-OM sediments. Our results suggest that the predictive ability of SQGs could be improved by models of metal interactions with natural OM in sediment and pore water.

Effects of organic amendments on the toxicity and bioavailability of cadmium and copper in spiked formulated sediments.

PubMed

Besser, John M; Brumbaugh, William G; May, Thomas W; Ingersoll, Christopher G

2003-04-01

We evaluated the partitioning and toxicity of cadmium (Cd) and copper (Cu) spiked into formulated sediments containing two types of organic matter (OM), i.e., cellulose and humus. Amendments of cellulose up to 12.5% total organic carbon (TOC) did not affect partitioning of Cd or Cu between sediment and pore water and did not significantly affect the toxicity of spiked sediments in acute toxicity tests with the amphipod Hyalella azteca. In contrast, amendments of natural humus shifted the partitioning of hoth Cd and Cu toward greater concentrations in sediment and lesser concentrations in pore water and significantly reduced toxic effects of both metals. Thresholds for toxicity, based on measured metal concentrations in whole sediment, were greater for both Cd and Cu in sediments amended with a low level of humus (2.9% TOC) than in sediments without added OM. Amendments with a high level of humus (8.9% TOC) eliminated toxicity at the highest spike concentrations of both metals (sediment concentrations of 12.4 microg Cd/g and 493 microg Cu/g). Concentrations of Cd in pore water associated with acute toxicity were similar between sediments with and without humus amendments, suggesting that toxicity of Cd was reduced primarily by sorption to sediment OM. However, toxic effects of Cu in humus treatments were associated with greater pore-water concentrations than in controls, suggesting that toxicity of Cu was reduced both by sorption and by complexation with soluble ligands. Both sorption and complexation by OM tend to make proposed sediment quality guidelines (SQGs) based on total metal concentrations more protective for high-OM sediments. Our results suggest that the predictive ability of SQGs could be improved by models of metal interactions with natural OM in sediment and pore water.

Incorporating Bioaccessibility into Human Health Risk Assessment of Heavy Metals in Rice ( Oryza sativa L.): A Probabilistic-Based Analysis.

PubMed

Li, Tianyuan; Song, Yinxian; Yuan, Xuyin; Li, Jizhou; Ji, Junfeng; Fu, Xiaowen; Zhang, Qiang; Guo, Shuhai

2018-06-06

A systematic investigation into total and bioaccessible heavy metal concentrations in rice grains harvested from heavy metal-contaminated regions was carried out to assess the potential health risk to local residents. Arsenic, Cr, Cu, Pb, and Zn concentrations were within acceptable levels while Cd and Ni concentrations appeared to be much higher than in other studies. The bioaccessibity of As, Cd, and Ni was high (>25%) and could be well predicted from their total concentrations. The noncarcinogenic risk posed by As and Cd was significant. The carcinogenic risk posed by all bioaccessible heavy metals at the fifth percentile was 10-fold higher than the acceptable level, and Cd and Ni were the major contributors. The contribution of each metal to the combined carcinogenic risk indicates that taking pertinent precautions for different types of cancer, aimed at individuals with different levels of exposure to heavy metals, will greatly reduce morbidity and mortality rates.

Comparative tissue distribution of metals in birds in Sweden using ICP-MS and laser ablation ICP-MS.

PubMed

Ek, Kristine H; Morrison, Gregory M; Lindberg, Peter; Rauch, Sébastien

2004-08-01

Cadmium, copper, lead, palladium, platinum, rhodium, and zinc profiles were investigated along feather shafts of raptor and other bird species by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The distribution of external versus internal metal contamination of feathers was investigated. The species examined were peregrine falcon (Falco peregrinus), sparrowhawk ( Accipiter nisus), willow grouse (Lagopus lagopus), and house sparrow (Passer domesticus) in Sweden. For habitat comparisons, total Cu, Pb, Zn, and Cd concentrations were analyzed by ICP-MS in feathers of the examined species as well as captive peregrine falcon. For investigation of metal distribution and correlation in different biological materials of raptors, total concentrations of Cu, Pb, Cd, and Zn were also investigated by ICP-MS in feathers, eggs, blood, feces, liver, and kidney of wild peregrine falcon from southwestern Sweden. Laser ablation of feathers revealed that Pb contamination is both external and internal, Zn contamination is internal, and Cd and Cu contamination is predominantly internal, with a few externally attached particles of high concentration. Pb, Cu, and Cd signal intensities were highest in urban habitats and contamination was mainly external in feathers. The background signal intensity of Zn was also higher in birds from urban habitats. The laser ablation profile of PGE (Pt, Pd, Rh) demonstrated that PGE contamination of feathers consists almost exclusively of externally attached PGE-containing particles, with little evidence of internally deposited PGE.Generally, total metal concentrations in feathers were highest in sparrowhawk and house sparrow due to their urban habitat. Total Cu, Zn, and Cd concentrations were highest in liver and kidney due to binding to metallothionein, while the total Pb concentration was highest in feces due to the high excretion rate of Pb. A decreasing temporal trend for Pb in feathers, showing that Pb levels in feathers have decreased since the introduction of nonleaded petrol, is also discussed.

Chemical behavior of Cu, Zn, Cd, and Pb in a eutrophic reservoir: speciation and complexation capacity.

PubMed

Tonietto, Alessandra Emanuele; Lombardi, Ana Teresa; Choueri, Rodrigo Brasil; Vieira, Armando Augusto Henriques

2015-10-01

This research aimed at evaluating cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) speciation in water samples as well as determining water quality parameters (alkalinity, chlorophyll a, chloride, conductivity, dissolved organic carbon, dissolved oxygen, inorganic carbon, nitrate, pH, total suspended solids, and water temperature) in a eutrophic reservoir. This was performed through calculation of free metal ions using the chemical equilibrium software MINEQL+ 4.61, determination of labile, dissolved, and total metal concentrations via differential pulse anodic stripping voltammetry, and determination of complexed metal by the difference between the total concentration of dissolved and labile metal. Additionally, ligand complexation capacities (CC), such as the strength of the association of metals-ligands (logK'ML) and ligand concentrations (C L) were calculated via Ruzic's linearization method. Water samples were taken in winter and summer, and the results showed that for total and dissolved metals, Zn > Cu > Pb > Cd concentration. In general, higher concentrations of Cu and Zn remained complexed with the dissolved fraction, while Pb was mostly complexed with particulate materials. Chemical equilibrium modeling (MINEQL+) showed that Zn(2+) and Cd(2+) dominated the labile species, while Cu and Pb were complexed with carbonates. Zinc was a unique metal for which a direct relation between dissolved species with labile and complexed forms was obtained. The CC for ligands indicated a higher C L for Cu, followed by Pb, Zn, and Cd in decreasing amounts. Nevertheless, the strength of the association of all metals and their respective ligands was similar. Factor analysis with principal component analysis as the extraction procedure confirmed seasonal effects on water quality parameters and metal speciation. Total, dissolved, and complexed Cu and total, dissolved, complexed, and labile Pb species were all higher in winter, whereas in summer, Zn was mostly present in the complexed form. A high degree of deterioration of the reservoir was confirmed by the results of this study.

Exposure of xenopus laevis tadpoles to cadmium reveals concentration-dependent bimodal effects on growth and monotonic effects on development and thyroid gland activity

USGS Publications Warehouse

Sharma, Bibek; Patino, R.

2008-01-01

Xenopus laevis were exposed to 0-855 ??g cadmium (Cd)/l (measured concentrations) in FETAX medium from fertilization to 47 days postfertilization. Measurements included embryonic survival and, at 47 days, tadpole survival, snout-vent length, tail length, total length, hindlimb length, weight, Nieuwkoop-Faber (NF) stage of development, initiation of metamorphic climax (??? NF 58), and thyroid follicle cell height. Embryonic and larval survival were unaffected by Cd. Relative to control tadpoles, reduced tail and total length were observed at 0.1- 8 and at 855 ??g Cd/l; and reduced snout-vent length, hindlimb length, and weight were observed at 0.1-1 and at 855 ??g Cd/l. Mean stage of development and rate of initiation of climax were unaffected by Cd at 0-84 ??g/l; however, none of the tadpoles exposed to 855 ??g Cd/l progressed beyond mid-premetamorphosis (NF 51). Thyroid glands with fully formed follicles were observed in all tadpoles ??? NF 49 examined. Follicle cell height was unaffected by Cd at 0-84 ??g/l but it was reduced at 855 ??g/l; in the latter, cell height was reduced even when compared with NF 49-51 tadpoles pooled from the 0 to 84 ??g Cd/l groups. In conclusion, (1) Cd affected tadpole growth in a bimodal pattern with the first and second inhibitory modes at concentrations below and above 84 ??g Cd/l, respectively; (2) exposure to high Cd concentrations (855 ??g/l) reduced thyroid activity and arrested tadpole development at mid-premetamorphosis; and (3) unlike its effect on growth, Cd inhibited tadpole development and thyroid function in a seemingly monotonic pattern.

Effective Phytoextraction of Cadmium (Cd) with Increasing Concentration of Total Phenolics and Free Proline in Cannabis sativa (L) Plant Under Various Treatments of Fertilizers, Plant Growth Regulators and Sodium Salt.

PubMed

Ahmad, Ayaz; Hadi, Fazal; Ali, Nasir

2015-01-01

The comparative effect of fertilizers (NPK), plant growth regulators (GA3, IAA, Zeatin) and sodium chloride (NaCl) on Cd phytoaccumulation, proline and phenolics production in Cannabis sativa was evaluated. Proline and phenolices were correlated with Cd contents in plant. Cd significantly reduced the plant growth. Fertilizers application (in combination) most significantly increased the growth (19 cm root and 47 cm shoot) on Cd contaminated soil. All treatments increased the Cd contents in plant tissues. This increase was highly significant in fertilizers treated plants (1101, 121 and 544 ppm in roots, stem and leaves respectively). Significantly positive correlation was found between Cd concentration and dry biomass of root (R2=0.7511) and leaves (R2=0.5524). All treatments significantly increased the proline and total phenolics and maximum was recorded in NaCl treated plants followed by fertilizers. Proline was higher in roots while phenolics in leaves. The correlation between proline and phenolics was positive in leaf (R2=0.8439) and root (R2=0.5191). Proline and phenolics showed positive correlation with Cd concentration in plant. Conclusively, fertilizers in combination seem to be the better option for Cd phytoextraction. Further investigation is suggested to study the role of phenolics and proline in Cd phytoextraction.

Organic matter and salinity modify cadmium soil (phyto)availability.

PubMed

Filipović, Lana; Romić, Marija; Romić, Davor; Filipović, Vilim; Ondrašek, Gabrijel

2018-01-01

Although Cd availability depends on its total concentration in soil, it is ultimately defined by the processes which control its mobility, transformations and soil solution speciation. Cd mobility between different soil fractions can be significantly affected by certain pedovariables such as soil organic matter (SOM; over formation of metal-organic complexes) and/or soil salinity (over formation of metal-inorganic complexes). Phytoavailable Cd fraction may be described as the proportion of the available Cd in soil which is actually accessible by roots and available for plant uptake. Therefore, in a greenhouse pot experiment Cd availability was observed in the rhizosphere of faba bean exposed to different levels of SOM, NaCl salinity (50 and 100mM) and Cd contamination (5 and 10mgkg -1 ). Cd availability in soil does not linearly follow its total concentration. Still, increasing soil Cd concentration may lead to increased Cd phytoavailability if the proportion of Cd 2+ pool in soil solution is enhanced. Reduced Cd (phyto)availability by raised SOM was found, along with increased proportion of Cd-DOC complexes in soil solution. Data suggest decreased Cd soil (phyto)availability with the application of salts. NaCl salinity affected Cd speciation in soil solution by promoting the formation of CdCl n 2-n complexes. Results possibly suggest that increased Cd mobility in soil does not result in its increased availability if soil adsorption capacity for Cd has not been exceeded. Accordingly, chloro-complex possibly operated just as a Cd carrier between different soil fractions and resulted only in transfer between solid phases and not in increased (phyto)availability. Copyright © 2017 Elsevier Inc. All rights reserved.

Concentration, Complexation and Chemical Speciation of Zinc and Cadmium in the Western North Pacific Ocean : Exploring Sources and Transport of Trace Metals and Complexing Ligands.

NASA Astrophysics Data System (ADS)

Carrasco, G. G.; Morton, P. L.; Donat, J. R.

2008-12-01

We determined Zn and Cd total dissolved (0.45 µm-filtered) concentrations, organic complexation and chemical speciation in surface water samples collected along the transect of the 2002 IOC Baseline Contaminant Survey expedition in the Western North Pacific and in vertical profile water samples at nine stations. The goals of this work were (1) to compare and contrast various trace metal sources, including both natural and anthropogenic atmospheric deposition, upwelling, marginal seas and others; (2) to study the organic ligand sources, generally thought to be phytoplankton; and (3) to investigate metal and ligand transport mechanisms, residence times and eventual upwelling in the Eastern North Pacific. Total dissolved (TD) Zn and Cd values were obtained using a combination of differential pulse stripping anodic voltammetry (DPASV), preconcentration with 8-HQ or APDC/DDC and quantification at ICPMS or AA. Organic complexation and chemical speciation of Zn and Cd were determined simultaneously using DPASV at a thin-mercury-film, glassy-carbon-disk-electrode. Surface transect TDZn and TDCd concentrations were low in the Subtropical Gyre (STG), in contrast with high values in the Western Subarctic Gyre (WSG). Zn and Cd were organically complexed in most surface samples: at least one ligand class was detected for Zn and Cd, whose conditional stability constants (log K') averaged 10.2 and 10.5, respectively. These ligands were found in excess of the total dissolved metal throughout the region of study except in the WSG for Cd. Vertical distributions of TDZn and TDCd exhibited nutrient-type profiles for all the STG stations. While constant Zn/Si and Cd/P values were observed throughout the water column in the WSG, some deviations were observed within the STG. In addition, the mode and intermediate water masses of the STG displayed very high concentrations of a Zn-complexing ligand (log K' 10.0) in excess of TDZn. As these water masses moved eastward, we observed that the ligand concentrations decreased. In contrast to the STG, the upper 1000m of the WSG showed elevated concentrations of both metals. Despite elevated surface (0-200m) Zn concentrations (~2nM), a Zn-complexing ligand (log K' 9.8) was found in excess of TDZn; below the photic layer, even higher TDZn concentrations might have saturated the ligand. A ligand for Cd was present in lower-than-TDCd concentrations in the same surface waters; below them, organic complexation of Cd was observed rarely in both STG and WSG regions. By studying the geographic distribution of the total dissolved metals and ligands, along with other dissolved and particulate tracers, possible sources and transport mechanisms can be contrasted and evaluated. Furthermore, the influence of these sources and transport mechanisms on the distribution of Zn and Cd chemical species and, ultimately, the bioavailability of these micronutrient metals can be studied.

Long-term changes in the extractability and bioavailability of zinc and cadmium after sludge application

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGrath, S.P.; Zhao, F.J.; Dunham, S.J.

2000-06-01

Changes in the extractability and uptake by crops of sludge metals in a long-term field experiment, started in 1942, were measured to assess whether Zn and Cd are either fixed by the sludge/soil constituents or are released as the sludge organic matter (OM) decomposes. Total and 0.1 M CaCl{sub 2}-extractable concentrations of Zn and Cd in soil and total concentrations in crops were measured on archived crop and soil samples. Extractability of Zn as a proportion of the total ranged from 0.5 to 3% and that of Cd from 4 to 18%, and were higher in sludge-amended than farmyard manuremore » or fertilizer-amended soils. Over a 23-yr period after 1961, when sludge was last applied, the extractability of both metals fluctuated, but neither decreased nor increased consistently. The relationships between total soil and crop metal concentrations were linear, with no evidence of a plateau across the range of soil metal concentrations achieved. The slopes of the soil-plant relationships depended on the type of crop or crop part examined, but were generally in the order red beet (Beta vulgaris L.) > sugar beet (Beta vulgaris L.) > carrot (Daucus carota L.) > barley (Hordeum vulgare L.). However, there also were large seasonal differences in metal concentrations in the crops. It is concluded from the available evidence that up to 23 yr after sludge applications cease, Zn and Cd extractability and bioavailability do not decrease.« less

Toxicological responses of Laeonereis acuta (Polychaeta, Nereididae) after acute, subchronic and chronic exposure to cadmium.

PubMed

Dolagaratz Carricavur, Arantxa; Chiodi Boudet, Leila; Romero, María Belén; Polizzi, Paula; Marcovecchio, Jorge Eduardo; Gerpe, Marcela

2018-03-01

The objective of this study was to analyze the toxicological responses of the estuarine polychaete Laeonereis acuta after acute (96h), subchronic (7 days) and chronic (14 days) exposure to cadmium (Cd). Concentrations of metallothioneins (MT), lipid peroxidation (LPO), total Cd and metal-rich granules (MRG) were evaluated. Seasonal variations of MT and LPO levels in the wild were also measured. Polychaetes were obtained in the Quequén estuary located southeast of Buenos Aires Province, Argentina. For the acute toxicity assay, individuals were exposed to 10; 30, 65; 310; 600; 1300; 2000; 4300; 8100; 16300µgCdL -1 , which included levels of environmental relevance and median lethal concentrations (LC 50 ) for related species of polychaete. Based on 96h LC 50 values, polychaetes were exposed to sublethal doses of Cd. The concentrations for both subchronic and chronic assays were: 10; 30; 65; 310; 600; 1300; 2000; 4300µgCdL -1 . The 96h LC 50 value was 8234.9µgL -1 , which was within the values reported for other species of polychaete, indicating a high tolerance to Cd. MT induction was not observed for any time exposure. In additoin, LPO levels showed no differences with respect to control levels, which indicated an absence of oxidative damage caused by Cd. However, the total Cd and MRG-Cd concentrations in L. acuta in all tested treatments showed significant differences with respect to control levels. L. acuta were able to accumulate Cd in their tissues in the form of granules which are the main mechanism of Cd detoxification. Copyright © 2017 Elsevier Inc. All rights reserved.

Tile Drainage Management Influences on Surface-Water and Groundwater Quality following Liquid Manure Application.

PubMed

Frey, Steven K; Topp, Ed; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Zoski, Erin; Lapen, David R

2013-01-01

This study investigated the potential for controlled tile drainage (CD) to reduce bacteria and nutrient loading to surface water and groundwater from fall-season liquid manure application (LMA) on four macroporous clay loam plots, of which two had CD and two had free-draining (FD) tiles. Rhodamine WT (RWT) was mixed into the manure and monitored in the tile water and groundwater following LMA. Tile water and groundwater quality were influenced by drainage management. Following LMA on the FD plots, RWT, nutrients, and bacteria moved rapidly via tiles to surface water; at the CD plots, tiles did not flow until the first post-LMA rainfall, so the immediate risk of LMA-induced contamination of surface water was abated. During the 36-d monitoring period, flow-weighted average specific conductance, redox potential, and turbidity, as well as total Kjeldahl N (TKN), total P (TP), NH-N, reactive P, and RWT concentrations, were higher in the CD tile effluent; however, because of lower tile discharge from the CD plots, there was no significant ( ≤ 0.05) difference in surface water nutrient and RWT loading between the CD and FD plots when all tiles were flowing. The TKN, TP, and RWT concentrations in groundwater also tended to be higher at the CD plots. Bacteria behaved differently than nutrients and RWT, with no significant difference in total coliform, , fecal coliform, fecal streptococcus, and concentrations between the CD and FD tile effluent; however, for all but , hourly loading was higher from the FD plots. Results indicate that CD has potential for mitigating bacteria movement to surface water. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLaughlin, M.J.; Tiller, K.G.; Beech, T.A.

Elevated Cd concentrations have been observed in potato (Solanum tuberosum L.) tubers from commercial crops in certain regions of southern Australia. Reasons for enhanced Cd uptake by tubers were investigated by a survey of commercial crops and associated soils. Eighty-nine sites were selected and paired tuber and soil samples taken. Concentration of Cd in tubers was compared to potato variety, tuber elemental composition, and chemical-physical characteristics of topsoil (0-150) and subsoil (150-300 mm). Tuber Cd concentrations were positively related to soil electrical conductivity (EC) and extractable Cl (R{sup 2} = 0.62, P < 0.001) in the topsoil, with extractable Clmore » accounting for more variation than EC. Tuber Cd concentrations were not strongly related (R{sup 2} = 0.23, P < 0.05) to potato variety alone. However, inclusion of variety and EDTA-extractable Zn with water-extractable Cl in a multivariate model resulted in a small but significant improvement in the variance accounted for by the model (R{sup 2} = 0.73, p < 0.001). Tuber Cd was unrelated to tuber concentrations of P or tuber but was positively related to concentrations of major cations in the tuber particularly Na. Soil pH, total C, EDTA-extractable Cd, or particle-size distribution were not correlated to tuber Cd concentrations, either singly or after inclusion in a multivariate model with soil Cl concentrations. As Cl is known to mobilize soil Cd and increase its phytoavailability, elevated Cd concentrations in potato tubers in southern Australia appear to be largely a result of the use of saline irrigation waters. 41 refs., 5 figs., 4 tabs.« less

Foliar zinc biofortification effects in Lolium rigidum and Trifolium subterraneum grown in cadmium-contaminated soil

PubMed Central

Damon, Paul; Rengel, Zed

2017-01-01

Zinc (Zn) is an important micronutrient that can alleviate cadmium (Cd) toxicity to plants and limit Cd entry into the food chain. However, little is known about the Zn-Cd interactions in pasture plants. We characterized the effects of foliar Zn application and Cd uptake by ryegrass (Lolium rigidum L.) and clover (Trifolium subterraneum L.) grown on Cd-contaminated soils; all combinations of foliar Zn applications (0, 0.25 and 0.5% (w/v) ZnSO4·7H2O) and soil Cd concentrations (0, 2.5 and 5 mg Cd kg-1) were tested. For both plant species, soil concentrations of DTPA-extractable Cd and Zn increased with an increase in the Cd and Zn treatments, respectively. Compared with L. rigidum, T. subterraneum accumulated, respectively, 3.3- and 4.1-fold more Cd in the 2.5-Cd and 5-Cd treatments and about 1.3-, 2.3- and 2.8-fold more Zn in the No-Zn, 0.25-Zn and 0.5-Zn treatments. Also, DTPA-Zn concentration was higher in soil after T. subterraneum than L. rigidum growth regardless of Zn applications. Foliar application of 0.25% (w/v) Zn significantly decreased the total Cd concentration in shoots of both species grown in the Cd-contaminated soil and ameliorated the adverse effects of Cd exposure on root growth, particularly in T. subterraneum. PMID:28950025

Effects of cadmium on some haematological and biochemical characteristics of Oreochromis niloticus (Linnaeus, 1758) dietary supplemented with tomato paste and vitamin E.

PubMed

Mekkawy, Imam A A; Mahmoud, Usama M; Wassif, Ekbal T; Naguib, Mervat

2011-03-01

The present study investigates the potential protective effects of tomato paste (9 mg/kg-lycopene) in comparison with vitamin E (50 mg/kg) against the impacts of cadmium (Cd) toxicity (4.64 mg/l: ¼ of 96 h LC50) on fishes Cd exposed for 15 and 30 days. Cd impacts were evaluated in terms of biological, haematological and biochemical characteristics. Cd significantly induced free radicals in serum and liver. The activities of aspartate aminotransferase and alanine aminotransferase in serum were significantly increased due to Cd. Treatment with Cd caused a significant increase in Lipid peroxidation and DNA fragmentation in liver tissue and serum glucose and total lipid. On the other hand, Cd significantly led to decline in serum total protein, blood haemoglobin, red blood cell count, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Dietary supplementation with vitamin E and/or tomato paste to Cd-exposed fish declined significantly the increased lipid peroxidation and DNA fragmentation in liver tissue and the increased aspartate aminotransferase, alanine aminotransferase, glucose and total lipid in serum to the normal condition. This supplementation also significantly increased the declined serum total protein, blood haemoglobin, red blood cell count, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration to the normal state. Cd impacts and tomato paste/or vitamin E supplementations did not reflected on the condition factor of the fish. These findings demonstrated the beneficial diet supplementation of tomato paste phytonutrients and vitamin E in counteracting the harmful effects of Cd on the characters investigated.

Speciation and distribution characteristics of heavy metals and pollution assessments in the sediments of Nashina Lake, Heilongjiang, China.

PubMed

Li, Miao; Zang, Shuying; Xiao, Haifeng; Wu, Changshan

2014-05-01

Sediment core samples from Nashina Lake, Heilongjiang, China were collected using a gravity sampler. The cores were sliced horizontally at 1 cm each to determine the particle size, total concentrations and speciation of Cd, Cr, Cu, Mn, Ni, Pb, and Zn. Total concentrations of heavy metals were extracted using an acid mixture (containing hydro fluoric acid, nitric acid, and sulphuric acid) and analyzed using an inductively coupled plasma spectrometry. A sequential extraction procedure was employed to separate chemical species. Analysis of results indicate that the concentrations of heavy metals in the sediments of Nashina Lake in descending order are Mn, Cr, Zn, Pb, Ni, Cu, and Cd. The ratios of the average concentrations of four heavy metals (e.g.Cr, Cu, Ni, Zn) to their background values were >1; and those of Mn, Cd, and Pb were >1. Moreover, some toxic metals were mainly distributed in bioavailable fractions. For instance, both Cd and Mn were typically found in Acid-extractable species or Fe-Mn oxide species, and thus can be easily remobilized and enter the food chain. Finally, the analysis of geo-accumulation index showed that anthropogenic pollution levels of Cr, Cu, Mn, Ni, Zn were low, but those of Pb and Cd were at the moderate level. As both Pb and Cd are toxic metals, it is highly necessary to prohibit their transformation and accumulation in the sediments.

Metal-contaminated potato crops and potential human health risk in Bolivian mining highlands.

PubMed

Garrido, Alan E; Strosnider, William H J; Wilson, Robin Taylor; Condori, Janette; Nairn, Robert W

2017-06-01

This study assessed metals in irrigation water, soil and potato crops impacted by mining discharges, as well as potential human health risk in the high desert near the historic mining center of Potosí, Bolivia. Metal concentrations were compared with international concentration limit guidelines. In addition, an ingested average daily dose and minimum risk level were used to determine the hazard quotient from potato consumption for adults and children. Irrigation water maximum concentrations of Cd, Pb and Zn in mining-impacted sites were elevated 20- to 1100-fold above international concentration limit guidelines. Agricultural soils contained total metal concentrations of As, Cd, Pb and Zn that exceeded concentration limits in agricultural soil guidelines by 22-, 9-, 3- and 12-fold, respectively. Potato tubers in mining-impacted sites had maximum concentrations of As, Cd, Pb and Zn that exceeded concentration limits in commercially sold vegetables by 9-, 10-, 16- and fourfold, respectively. Using conservative assumptions, hazard quotients (HQ) for potatoes alone were elevated for As, Cd and Pb among children (range 1.1-71.8), in nearly all of the mining-impacted areas; and for As and Cd among adults (range 1.2-34.2) in nearly all of the mining-impacted areas. Only one mining-impacted area had a Pb adult HQ for potatoes above 1 for adults. Toxic trace elements in a major regional dietary staple may be a greater concern than previously appreciated. Considering the multitude of other metal exposure routes in this region, it is likely that total HQ values for these metals may be substantially higher than our estimates.

Cadmium and zinc uptake by volunteer willow species and elder rooting in polluted dredged sediment disposal sites.

PubMed

Vandecasteele, Bart; De Vos, Bruno; Tack, Filip M G

2002-11-01

Salix species and Sambucus nigra L. (elder) naturally invade dredged sediment landfills and are commonly encountered on substrates contaminated with heavy metals. Foliar concentrations of Cd and Zn in four Salix species and elder were explored in the field. Metal contents in dredged sediment derived soils were elevated compared to baseline concentration levels reported for Flanders. To evaluate foliar concentrations, reference data were compiled from observations in nurseries, young plantations and unpolluted sites with volunteer willow vegetation. Willows grown on polluted dredged sediment landfills showed elevated foliar Cd and Zn concentrations (>6.6 mg Cd/kg DW and >700 mg Zn/kg DW). This was not the case for elder. For willow, a significant relation was found between soil total Zn or Cd and foliar Zn or Cd, regardless of age, species, or clone. Willows proved to be useful bioindicators. Results indicated a possible threat in long-term habitat development of willow brushwood from transfer of Cd and Zn to the food web.

Cadmium tolerance and phytoremediation potential of acacia (Acacia nilotica L.) under salinity stress.

PubMed

Shabir, Rahat; Abbas, Ghulam; Saqib, Muhammad; Shahid, Muhammad; Shah, Ghulam Mustafa; Akram, Muhammad; Niazi, Nabeel Khan; Naeem, Muhammad Asif; Hussain, Munawar; Ashraf, Farah

2018-06-07

In this study, we explored the effect of salinity on cadmium (Cd) tolerance and phytoremediation potential of Acacia nilotica. Two-month-old uniform plants of A. nilotica were grown in pots contaminated with various levels of Cd (0, 5, 10, and 15 mg kg -1 ), NaCl (0%, 0.5%, 1.0% (hereafter referred as salinity), and all possible combinations of Cd + salinity for a period of six months. Results showed that shoot and root growth, biomass, tissue water content and chlorophyll (chl a, chl b, and total chl a+b) contents decreased more in response to salinity and combination of Cd + salinity compared to Cd alone. Shoot and root K concentrations significantly decreased with increasing soil Cd levels, whereas Na and Cl concentrations were not affected significantly. Shoot and root Cd concentrations, bioconcentration factor (BCF) and translocation factor (TF) increased with increasing soil Cd and Cd + salinity levels. At low level of salinity (0.5%), shoot and root Cd uptake enhanced, while it decreased at high level of salinity (1.0%). Due to Cd tolerance, high shoot biomass and shoot Cd uptake, this tree species has some potential for phytoremediation of Cd from the metal contaminated saline and nonsaline soils.

Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae).

PubMed

Chia, Mathias Ahii; Lombardi, Ana Teresa; da Graça Gama Melão, Maria; Parrish, Christopher C

2015-03-01

Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C. vulgaris was used to investigate the influence of cadmium (10(-7) and 2.0×10(-8)molL(-1) Cd) under varying nitrogen (2.9×10(-6), 1.1×10(-5) and 1.1×10(-3)molL(-1)N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C. vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production. Copyright © 2015 Elsevier B.V. All rights reserved.

[Reducing cadmium content of rice grains by means of flooding and a few problems].

PubMed

Kawasaki, Akira; Arao, Tomohito; Ishikawa, Satoru

2012-01-01

The effects of water management in rice paddies on the levels of cadmium (Cd) and arsenic (As) in Japanese rice grains were tested. In order to reduce the Cd concentration in rice grains, flooding for 3 weeks before and after heading was most effective, but this treatment increased As concentration considerably. Aerobic treatment was effective in reducing As concentration in rice grains, but increased Cd concentration markedly. In the pot experiment, flooding treatment after heading was more effective than flooding treatment before heading in reducing both Cd and As concentrations in rice grains. The concentration of dimethylarsinic acid (DMA) in rice grains was very low under aerobic conditions, but increased in the continuous-flooding treatment. In the field experiment, the grain As concentration in the case of flooding for 3 weeks before and after heading was higher than that in the case of intermittent irrigation. The ratios of DMA to the total As concentration were 3-52% in the pot experiment and 7-13% in the field experiment.

Cadmium accumulations and bioavailability in soils from long-term phosphorus fertilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulla, D.J.; Page, A.L.; Ganje, T.J.

1980-07-01

Soils from citrus groves that had been fertilized with the equivalent of approximately 175 kg P/ha per year (as treble superphosphate (TSP)) over a 36-year period were sampled and analyzed for total P, Cd, and Zn as well as water-soluble P and Cd. A P fertilization rate of 175 kg/ha is much higher than normal field rates, which are typically about 30 kg/ha. Concentrations of total Cd in surface soil were highly correlated (r = 0.89) with concentrations of total P. The concentrations of Cd in surface soil receiving broadcast P for 36 years averaged 1.0 ..mu..g/g, and were considerablymore » greater than those of the controls, which showed a mean concentration of 0.07 ..mu..g/g. Phosphorus in soil saturation paste extracts ranged from 0.10 ..mu..g/ml (controls) to 8.87 ..mu..g/ml in P fertilized soils. Water-soluble saturation extract Cd ranged from 0.008 ..mu..g/ml in controls to 0.017 ..mu..g/ml in fertilized soils, and was not well correlated with water-soluble P. Cadmium levels in barley (Hordeum vulgare var. U.C. 566) grain and leaves grown in the field on soil subject to long-term heavy P fertilization were not elevated above levels in barley grown on the control soil. Swiss chard (Beta vulgaris var. cicla) was grown in the greenhouse on the above surface soils collected from the field. Although Cd levels averaging 1.6 ..mu..g/g in plant tissue were significantly elevated over those on the control soil (0.26 ..mu..g/gm), no yield depression was observed.« less

Associations of cadmium, zinc, and lead in soils from a lead and zinc mining area as studied by single and sequential extractions.

PubMed

Anju, M; Banerjee, D K

2011-05-01

An exploratory study of the area surrounding a historical Pb-Zn mining and smelting area in Zawar, India, detected significant contamination of the terrestrial environment by heavy metals. Soils (n=87) were analyzed for pH, EC, total organic matter (TOM), Pb, Zn, Mn, and Cd levels. The statistical analysis indicated that the frequency distribution of the analyzed parameters for these soils was not normal. The median concentrations of metals in surface soils were: Pb 420.21 μ g/g, Zn 870.25 μ g/g, Mn 696.70 μ g/g, and Cd 2.09 μ g/g. Zn concentrations were significantly correlated with Cd (r=0.867), indicating that levels of Cd are dependent on Zn. However, pH, electrical conductivity and total organic matter were not correlated significantly with Cd, Pb, Zn, and Mn. To assess the potential mobility of Cd, Pb, and Zn in soils, single (EDTA) as well as sequential extraction scheme (modified BCR) were applied to representative (n=23) soil samples. The amount of Cd, Pb, and Zn extracted by EDTA and their total concentrations showed linear positive correlation, which are statistically significant (r values for Cd, Pb, and Zn being 0.901, 0.971, and 0.795, respectively, and P values being <0.001). The correlation coefficients indicate a strong relation between EDTA-extractable metal and total metal. These results appear to justify the use of 'total' metal contents as a useful preliminary indicator of areas where the risks of metal excess or deficiency are high. The EDTA extractability was maximum for Cd followed by Pb and Zn in soils from all the locations. As indicated by single extraction, the apparent mobility and potential bioavailability of metals in soils followed the order: Cd ≥ Pb > > Zn. Soil samples were sequentially extracted (modified BCR) so that solid pools of Cd, Zn, and Pb could be partitioned into four operationally defined fractions viz. acid-soluble, reducible, oxidizable, and residual. Cadmium was present appreciably (39.41%) in the acid-soluble fraction and zinc was predominantly associated (32.42%) with residual fraction. Pb (66.86%) and Zn (30.44%) were present mainly in the reducible fraction. Assuming that the mobility and bioavailability are related to solubility of geochemical forms of metals and decrease in the order of extraction, the apparent mobility and potential metal bioavailability for these contaminated soil samples is Cd > Zn > Pb.

Identification of rice cultivar with exclusive characteristic to Cd using a field-polluted soil and its foreground application.

PubMed

Zhan, Jie; Wei, Shuhe; Niu, Rongcheng; Li, Yunmeng; Wang, Shanshan; Zhu, Jiangong

2013-04-01

Using low-accumulative plant, especially excluder crop, to safely produce food is one of the very important technologies of phytoremediation, which is practical to safe production and long-term remediation of heavy metal-contaminated soil. A pot experiment using field cadmium (Cd)-contaminated soil (Cd concentration was 0.75 mg kg(-1)) was conducted to compare Cd accumulation differences among 39 normal rice cultivars (Japonica) in Shenyang region of China for food safety and high grain yield aim. The results showed that brown grain Cd concentration in 12 rice cultivars of a total of 39 tested cultivars was lower than 0.2 mg kg(-1) (Agricultural Trade Standard of Nonpollution Food for Rice of China, NY 5115-2008). In these 12 cultivars, Cd enrichment factors (Cd concentration ratio in shoot to that in soil) of nine cultivars were lower than 1. Likewise, Cd translocation factors (Cd concentration ratio in shoot to that in root) of eight cultivars were lower than the 0.28 average. Furthermore, grain yield per pot of seven cultivars were higher than the average 18.4 g pot(-1). Four cultivars, i.e., Shendao 5, Tianfu 1, Fuhe 90, and Yanfeng 47 showed Cd-exclusive characteristic and better foreground application.

Silicon alleviates Cd stress of wheat seedlings (Triticum turgidum L. cv. Claudio) grown in hydroponics.

PubMed

Rizwan, M; Meunier, J-D; Davidian, J-C; Pokrovsky, O S; Bovet, N; Keller, C

2016-01-01

We investigated the potential role of silicon in improving tolerance and decreasing cadmium (Cd) toxicity in durum wheat (Triticum turgidum L. durum) either through a reduced Cd uptake or exclusion/sequestration in non-metabolic tissues. For this, plants were grown in hydroponic conditions for 10 days either in presence or absence of 1 mM Si and for 11 additional days in various Cd concentrations (0, 0.5, 5.0 and 50 μM). After harvesting, morphological and physiological parameters as well as elemental concentrations were recorded. Cadmium caused reduction in growth parameters, photosynthetic pigments and mineral nutrient concentrations both in shoots and roots. Shoot and root contents of malate, citrate and aconitate increased, while contents of phosphate, nitrate and sulphate decreased with increasing Cd concentrations in plants. Addition of Si to the nutrient solution mitigated these adverse effects: Cd concentration in shoots decreased while concentration of Cd adsorbed at the root cell apoplasmic level increased together with Zn uptake by roots. Overall, total Cd uptake decreased in presence of Si. There was no co-localisation of Cd and Si either at the shoot or at the root levels. No Cd was detected in leaf phytoliths. In roots, Cd was mainly detected in the cortical parenchyma and Si at the endodermis level, while analysis of the outer thin root surface of the plants grown in the 50 μM Cd + 1 mM Si treatment highlighted non-homogeneous Cd and Si enrichments. These data strongly suggest the existence of a root localised protection mechanism consisting in armoring the root surface by Si- and Cd-bearing compounds and in limiting root-shoot translocation.

[Effect of Ryegrass and Arbuscular Mycorrhizal on Cd Absorption by Varieties of Tomatoes and Cadmium Forms in Soil].

PubMed

Chen, Yong-qin; Jiang, Ling; Xu, Wei-hong; Chi, Sun-lin; Chen, Xu-gen; Xie, Wen-wen; Xiong, Shi- juan; Zhang, Jin-zhong; Xiong, Zhi-ting

2015-12-01

Field trial was carried out to investigate the effects of ryegrass and arbuscular mycorrhizal single or compound treatment to two varieties of tomato ("Defu mm-8" and "Luobeiqi") on the plant growth, concentrations and accumulations of Cd as well as the impact on microorganisms, enzyme activities, pH and Cd forms in soil when exposed to Cd (5.943 mg · kg⁻¹). The results showed that dry weights of fruit, root, stem, leaf and plant significantly increased by single or compound treatment of ryegrass and arbuscular mycorrhizal by 14.1%-38.4% and 4.2%-18.3%, 20.9%-31.5% and 8.4%-10.3%, 13.0%-16.8% and 3.0%-9.5%, 10.7%- 16.8% and 2.7%-7.6%, 14.3%-36.6% and 4.5%-16.8%, respectively. The amounts of bacteria, fungi, actinomycetes of soil and the activities of urease, invertase, acid phosphatase, catalase in soil were increased by single or compound treatment of ryegrass and arbuscular mycorrhizal, and the soil microorganism amounts and enzyme activities significantly differed between the two varieties of tomato and treatments (P < 0.05). Soil pH was increased by single or compound treatment of ryegrass and arbuscular mycorrhizal, while the concentrations of EXC-Cd, CAB-Cd, Fe-Mn-Cd and total Cd in soil were decreased, and the total Cd content was decreased by 16.9%-27.8%. Cadmium concentrations in fruit, leaf, stem and root of both varieties were significantly decreased by 6.9%-40.9%, 5.7%-40.1%, 4.6%-34.7% and 9.8%-42.4%, respectively. Cadmium accumulations in tomato were in order of leaf > stem > root > fruit. Comparing the two tomato varieties, Cd concentrations and Cd accumulations in fruit and plant were in order of "Luobeiqi" < "Defu mm-8" in the presence or absence of single or compound treatment of ryegrass and arbuscular mycorrhizal.

Adsorption of Cd(II) Metal Ion on Adsorbent beads from Biomass Saccharomycess cereviceae - Chitosan

NASA Astrophysics Data System (ADS)

Hasri; Mudasir

2018-01-01

The adsorbent beads that was preparation from Saccharomycess cereviceae culture strain FN CC 3012 and shrimp shells waste and its application for adsorption of Cd (II) metal ion has been studied. The study start with combination of Saccharomycess cereviceae biomass to chitosan (Sc-Chi), contact time, pH of solution and initial concentration of cations. Total Cd(II) metal ion adsorbed was calculated from the difference of metal ion concentration before and after adsorption by AAS. The results showed that optimum condition for adsorption of Cd(II) ions by Sc-Chi beads was achieved with solution pH of 4, contact time of 60 minutes and initial concentration adsorption 100mg/L. The hydroxyl (-OH) and amino (-NH2) functional groups were believed to be responsible for the adsorption of Cd(II) ions.

Histopathological changes in the head kidney induced by cadmium in a neotropical fish Colossoma macropomum.

PubMed

Salazar-Lugo, R; Vargas, A; Rojas, L; Lemus, M

2013-01-01

We evaluated the effect of cadmium (Cd) on the structure and function of the head kidney in the freshwater fish Colossoma macropomum (C. macropomum). Juveniles were exposed to 0.1 mg/L CdCl2 for 31 days. Blood samples were examined using hematological tests and head kidney histology was determined by light microscopy. The concentration of Cd in the head and trunk kidneys was measured using an atomic absorption spectrophotometer. Cd produced histopathological changes in the head kidney, the most evident of these being: the thickening of the vein wall, an increase in the number of basophils/mast cells close to blood vessels and a severe depletion of hematopoietic precursors especially the granulopoietic series. In the blood, a decrease in the total leucocytes and hemoglobin concentration was observed. Cd-exposed fish showed higher Cd concentrations in the trunk kidney than the head kidney. In conclusion, exposure to Cd affected precursor hematopoietic cells in C. macropomum.

Histopathological changes in the head kidney induced by cadmium in a neotropical fish Colossoma macropomum

PubMed Central

Salazar-Lugo, R.; Vargas, A.; Rojas, L.; Lemus, M.

2013-01-01

We evaluated the effect of cadmium (Cd) on the structure and function of the head kidney in the freshwater fish Colossoma macropomum (C. macropomum). Juveniles were exposed to 0.1 mg/L CdCl2 for 31 days. Blood samples were examined using hematological tests and head kidney histology was determined by light microscopy. The concentration of Cd in the head and trunk kidneys was measured using an atomic absorption spectrophotometer. Cd produced histopathological changes in the head kidney, the most evident of these being: the thickening of the vein wall, an increase in the number of basophils/mast cells close to blood vessels and a severe depletion of hematopoietic precursors especially the granulopoietic series. In the blood, a decrease in the total leucocytes and hemoglobin concentration was observed. Cd-exposed fish showed higher Cd concentrations in the trunk kidney than the head kidney. In conclusion, exposure to Cd affected precursor hematopoietic cells in C. macropomum. PMID:26623329

Material properties of Cd1-xMgxO alloys synthesized by radio frequency sputtering

NASA Astrophysics Data System (ADS)

Chen, Guibin; Yu, K. M.; Reichertz, L. A.; Walukiewicz, W.

2013-07-01

We have studied structural, electrical, and optical properties of sputter deposited ternary CdMgO alloy thin films with total Mg concentration as high as 44%. We found that only a fraction (50%-60%) of Mg is incorporated as substitutional Mg contributing to the modification of the electronic structures of the alloys. The electrical and optical results of the Cd1-xMgxO alloys are analyzed in terms of a large upward shift of the conduction band edge with increasing Mg concentration. With the increase of the intrinsic bandgap, appropriately doped Cd-rich CdMgO alloys can be potentially useful as transparent conductors for photovoltaics.

Anthropogenic sources and environmentally relevant concentrations of heavy metals in surface water of a mining district in Ghana: a multivariate statistical approach.

PubMed

Armah, Frederick A; Obiri, Samuel; Yawson, David O; Onumah, Edward E; Yengoh, Genesis T; Afrifa, Ernest K A; Odoi, Justice O

2010-11-01

The levels of heavy metals in surface water and their potential origin (natural and anthropogenic) were respectively determined and analysed for the Obuasi mining area in Ghana. Using Hawth's tool an extension in ArcGIS 9.2 software, a total of 48 water sample points in Obuasi and its environs were randomly selected for study. The magnitude of As, Cu, Mn, Fe, Pb, Hg, Zn and Cd in surface water from the sampling sites were measured by flame Atomic Absorption Spectrophotometry (AAS). Water quality parameters including conductivity, pH, total dissolved solids and turbidity were also evaluated. Principal component analysis and cluster analysis, coupled with correlation coefficient analysis, were used to identify possible sources of these heavy metals. Pearson correlation coefficients among total metal concentrations and selected water properties showed a number of strong associations. The results indicate that apart from tap water, surface water in Obuasi has elevated heavy metal concentrations, especially Hg, Pb, As, Cu and Cd, which are above the Ghana Environmental Protection Agency (GEPA) and World Health Organisation (WHO) permissible levels; clearly demonstrating anthropogenic impact. The mean heavy metal concentrations in surface water divided by the corresponding background values of surface water in Obuasi decrease in the order of Cd > Cu > As > Pb > Hg > Zn > Mn > Fe. The results also showed that Cu, Mn, Cd and Fe are largely responsible for the variations in the data, explaining 72% of total variance; while Pb, As and Hg explain only 18.7% of total variance. Three main sources of these heavy metals were identified. As originates from nature (oxidation of sulphide minerals particularly arsenopyrite-FeAsS). Pb derives from water carrying drainage from towns and mine machinery maintenance yards. Cd, Zn, Fe and Mn mainly emanate from industry sources. Hg mainly originates from artisanal small-scale mining. It cannot be said that the difference in concentration of heavy metals might be attributed to difference in proximity to mining-related activities because this is inconsistent with the cluster analysis. Based on cluster analysis SN32, SN42 and SN43 all belong to group one and are spatially similar. But the maximum Cu concentration was found in SN32 while the minimum Cu concentration was found in SN42 and SN43.

Phytoavailability, human risk assessment and transfer characteristics of cadmium and zinc contamination from urban gardens in Kano, Nigeria.

PubMed

Abdu, Nafiu; Agbenin, John O; Buerkert, Andreas

2011-12-01

Quantitative data about phytoavailability and transfer into consumed plant parts for heavy metals in intensively managed urban vegetable production areas of sub-Saharan Africa are scarce. We therefore studied the transfer of zinc (Zn) and cadmium (Cd) from soil to the root and subsequent translocation to edible portions of four vegetables in six urban gardens. While respective diethylenetriaminepentaacetic acid (DTPA)-available Zn and Cd concentrations ranged from 18 to 66 mg kg(-1) and from 0.19 to 0.35 mg kg(-1) , respectively, in soils, total Zn and Cd were 8.4-256 mg kg(-1) and 0.04-1.7 mg kg(-1) in shoot parts. Metal transfer factor (MTF) ratios were higher in Zn (0.2-0.9) than in Cd (0.1-0.6). Our data suggest that total Zn concentration in soil is a reliable indicator to assess its transfer from soil to crop in lettuce, carrot and parsley, while for Cd DTPA-extractable concentration may be used to estimate soil-crop transfer of Cd in amaranthus and carrot. Overall, Cd was more easily translocated to the aerial plant parts than Zn. Zinc and Cd accumulation by vegetables in our soils is mainly a metabolically controlled process. Such accumulation can contaminate the ecosystem but under our conditions intake and ingestion of these metals will likely have to occur over a prolonged period to experience health hazard. Copyright © 2011 Society of Chemical Industry.

Assisted phytoremediation of Cd-contaminated soil using poplar rooted cuttings

NASA Astrophysics Data System (ADS)

Alizadeh, S.; Zahedi-Amiri, G.; Savaghebi-Firoozabadi, G.; Etemad, V.; Shirvany, A.; Shirmardi, M.

2012-07-01

To investigate the effect of amended substrates on cadmium uptake by one-year old poplar rooted cuttings a pot culture was carried out. Pots were filled with three substrates. Four treatments of Cd supply including were organized. The results showed that higher biomass productions in substrates A and B compare to substrate C, led to an increase total Cd uptake two times more than that in substrate C, at 150 mg kg-1 concentration. Meanwhile maximum total uptake occurred in substrate B at 100 mg kg-1 concentration. Using synthetic chelators such as ethylenediaminetetraacetic acid in order to achieve high removal rate led to increased environmental impacts while they are not expected when such environmental friendly approaches are applied.

Effects of cadmium on growth, metamorphosis and gonadal sex differentiation in tadpoles of the African clawed frog, Xenopus laevis

USGS Publications Warehouse

Sharma, Bibek; Patino, R.

2009-01-01

Xenopus laevis larvae were exposed to cadmium (Cd) at 0, 1, 8, 85 or 860 ??g L-1 in FETAX medium from 0 to 86 d postfertilization. Premetamorphic tadpoles were sampled on day 31; pre and prometamorphic tadpoles on day 49; and frogs (NF stage 66) between days 50 and 86. Survival, snout-vent length (SVL), tail length, total length, hindlimb length (HLL), initiation of metamorphic climax, size at and completion of metamorphosis, and gonadal condition and sex ratio (assessed histologically) were determined. Survival was unaffected by Cd until day 49, but increased mortality was observed after day 49 at 860 ??g Cd L-1. On day 31, when tadpoles were in early premetamorphosis, inhibitory effects on tadpole growth were observed only at 860 ??g Cd L-1. On day 49, when most tadpoles where in late premetamorphosis/early prometamorphosis, reductions in SVL, HLL and total length were observed at 8 and 860 but not 85 ??g L-1, thus creating a U-shaped size distribution at 0-85 ??g Cd L-1. However, this U-shaped size pattern was not evident in postmetamorphic individuals. In fact, frog size at completion of metamorphosis was slightly smaller at 85 ??g Cd L-1relative to control animals. These observations confirmed a recent report of a Cd concentration-dependent bimodal growth pattern in late-premetamorphic Xenopus tadpoles, but also showed that growth responses to varying Cd concentrations change with development. The fraction of animals initiating or completing metamorphosis during days 50-86 was reduced in a Cd concentration-dependent manner. Testicular histology and population sex ratios were unaffected by Cd suggesting that, unlike mammals, Cd is not strongly estrogenic in Xenopus tadpoles. ?? 2009 Elsevier Ltd.

Effects of cadmium on growth, metamorphosis and gonadal sex differentiation in tadpoles of the African clawed frog, Xenopus laevis

USGS Publications Warehouse

Sharma, Bibek; Patino, Reynaldo

2009-01-01

Xenopus laevis larvae were exposed to cadmium (Cd) at 0, 1, 8. 85 or 860 mu g L(-1) in FETAX medium from 0 to 86 d postfertilization. Premetamorphic tadpoles were sampled on day 3 1; pre and prometamorphic tadpoles on day 49; and frogs (NF stage 66) between days 50 and 86. Survival, snout-vent length (SVL), tail length, total length, hindlimb length (HLL), initiation of metamorphic climax, size at and completion of metamorphosis, and gonadal condition and sex ratio (assessed histologically) were determined. Survival was unaffected by Cd until day 49, but increased mortality was observed after day 49 at 860 mu g Cd L(-1). On day 31, when tadpoles were in early premetamorphosis, inhibitory effects on tadpole growth were observed only at 860 mu g Cd L(-1). On day 49, when most tadpoles where in late premetamorphosis/early prometamorphosis, reductions in SVL, HLL and total length were observed at 8 and 860 but not 85 mu g L(-1), thus creating a U-shaped size distribution at 0-85 mu g Cd L(-1). However, this U-shaped size pattern was not evident in postmetamorphic individuals. In fact, frog size at completion of metamorphosis was slightly smaller at 85 mu g Cd L(-1) relative to control animals. These observations confirmed a recent report of a Cd concentration-dependent bimodal growth pattern in late-premetamorphic Xenopus tadpoles, but also showed that growth responses to varying Cd concentrations change with development. The fraction of animals initiating or completing metamorphosis during days 50-86 was reduced in a Cd concentration-dependent manner. Testicular histology and population sex ratios were unaffected by Cd suggesting that, unlike mammals, Cd is not strongly estrogenic in Xenopus tadpoles.

Concentrations and bioaccessibilities of trace elements in barbecue charcoals.

PubMed

Sharp, Annabel; Turner, Andrew

2013-11-15

Total and bioaccessible concentrations of trace elements (Al, As, Cd, Cu, Fe, Hg, Mn, Ni, Pb and Zn) have been measured in charcoals from 15 barbecue products available from UK retailers. Total concentrations (available to boiling aqua regia) were greater in briquetted products (with mean concentrations ranging from 0.16 μg g(-1) for Cd to 3240 μg g(-1) for Al) than in lumpwoods (0.007 μg g(-1) for Cd to 28 μg g(-1) for Fe), presumably because of the use of additives and secondary constituents (e.g. coal) in the former. On ashing, and with the exception of Hg, elemental concentrations increased by factors ranging from about 1.5 to 50, an effect attributed to the combustion of organic components and offset to varying extents by the different volatilities of the elements. Concentrations in the ashed products that were bioaccessible, or available to a physiologically based extraction test (PBET) that simulates, successively, the chemical conditions in the human stomach and intestine, exhibited considerable variation among the elements studied. Overall, however, bioaccessible concentrations relative to corresponding total concentrations were greatest for As, Cu and Ni (attaining 100% in either or both simulated PBET phases in some cases) and lowest for Pb (generally <1% in both phases). A comparison of bioaccessible concentrations in ashed charcoals with estimates of daily dietary intake suggest that Al and As are the trace elements of greatest concern to human health from barbecuing. Copyright © 2013 Elsevier B.V. All rights reserved.

Trace elements in fish from Taihu Lake, China: levels, associated risks, and trophic transfer.

PubMed

Hao, Ying; Chen, Liang; Zhang, Xiaolan; Zhang, Dongping; Zhang, Xinyu; Yu, Yingxin; Fu, Jiamo

2013-04-01

Concentrations of eight trace elements [iron (Fe), manganese (Mn), zinc (Zn), chromium (Cr), mercury (Hg), cadmium (Cd), lead (Pb), and arsenic (As)] were measured in a total of 198 samples covering 24 fish species collected from Taihu Lake, China, in September 2009. The trace elements were detected in all samples, and the total mean concentrations ranged from 18.2 to 215.8 μg/g dw (dry weight). The concentrations of the trace elements followed the sequence of Zn>Fe>Mn>Cr>As>Hg>Pb>Cd. The measured trace element concentrations in fish from Taihu Lake were similar to or lower than the reported values in fish around the world. The metal pollution index was used to compare the total trace element accumulation levels among various species. Toxabramis swinhonis (1.606) accumulated the highest level of the total trace elements, and Saurogobio dabryi (0.315) contained the lowest. The concentrations of human non-essential trace elements (Hg, Cd, Pb, and As) were lower than the allowable maximum levels in fish in China and the European Union. The relationships between the trace element concentrations and the δ(15)N values of fish species were used to investigate the trophic transfer potential of the trace elements. Of the trace elements, Hg might be biomagnified through the food chain in Taihu Lake if the significant level of p-value was set at 0.1. No biomagnification and biodilution were observed for other trace elements. Copyright © 2012 Elsevier Inc. All rights reserved.

High Vitamin D-Binding Protein Concentration, Low Albumin, and Mode of Remission Predict Relapse in Crohn's Disease.

PubMed

Ghaly, Simon; Murray, Kevin; Baird, Angela; Martin, Katherine; Prosser, Ruth; Mill, Justine; Simms, Lisa A; Hart, Prue H; Radford-Smith, Graham; Bampton, Peter A; Lawrance, Ian C

2016-10-01

Vitamin D (25(OH)D) deficiency occurs in active Crohn's disease (CD) and may be secondary to reduced sunlight exposure and oral intake. Vitamin D-binding protein (VDBP) levels, however, fluctuate less with season and sunlight. The aim, therefore, was to examine patients with CD in remission and determine any associations between VDBP, serum 25(OH)D, and the calculated free 25(OH)D concentrations with the risk of disease flare. Subjects were identified from prospectively maintained inflammatory bowel disease databases at 3 teaching hospitals in Australia. Patients were in steroid-free clinical remission at the time of blood draw and were followed for at least 12 months. Total and epimer-25(OH)D3, VDBP concentrations, and genotypes were determined. A total of 309 patients with CD (46% men) met the inclusion criteria. A disease flare occurred in 100 (32.4%). Serum 25(OH)D3 was deficient (<50 nmol/L) in 36 (12%) and insufficient (50-75 nmol/L) in 107 (35%) patients. Total, free, and epimer-25(OH)D3 serum levels did not predict disease flare. Higher VDBP concentrations, however, significantly correlated with increased risk of disease flare (hazard ratio 1.2, 95% CI, 1.0-1.5). On multivariate analysis, VDBP concentration, low albumin, and medication-induced remission were significantly more associated with disease flare. VDBP genotypes were significantly associated with 25(OH)D and VDBP concentrations but not disease flare. Vitamin D deficiency was uncommon in our patients with CD in remission, and serum 25(OH)D3 did not predict disease flare, whereas higher VDBP concentrations were significantly associated with disease flare. Further investigations to explore the possible mechanisms for this association are warranted.

Physiological response of Cistus monspeliensis L. growing in two mine areas of the Iberian Pyrite Belt

NASA Astrophysics Data System (ADS)

Arenas Lago, Daniel; Carvalho, Luisa C.; Santos, Erika S.; Abreu, Maria Manuela; Andrade, María Luisa

2015-04-01

São Domingos and Lousal mines, nowadays in abandoned state, are located in Portugal, in the Iberian Pyrite Belt, a world-class volcanic-hosted massive sulfide. As a result of the intense mining activity large volumes of wastes containing metal(loid)s were partly exposed to weathering realising potential hazardous elements contaminating waters, soils and sediments. In both mines, a great part of the contaminated areas is relatively covered by several wild species. These species have developed mechanisms of response to oxidative stress originated by high concentration of metal(loid)s in plant tissues, whose presence leads to the formation of reactive oxygen species, thus causing oxidative damage. The main objective of this study was to evaluate changes in the ecophysiological behaviour of Cistus monspeliensis L., which grows spontaneously in both mine areas, in soils containing high concentrations of metal(loid)s. With this purpose, the variation of some physiological parameters was analysed in order to identify which parameters can be indicators of the plant'sresponse to oxidative stress. Representative soils from rhizosphere and plants were sampled, in the same locations, in different areas of São Domingos and Lousal mines and in an uncontaminated area nearby São Domingos. Soils were characterized for the classic properties. Multielemental total concentration was analysed in soils and plants (shoots and roots), and multielemental concentration in the available fraction of soils. Pigments (chlorophylls, anthocyanins and carotenoids), glutathione, ascorbate, H2O2 and antioxidative enzyme activities were measured in plant shoots. In general, total and available concentrations (mg/kg) of Zn (total 149-463; available 2-16), As (total 62-3030; available 0.03-1.9), Cd (total 0.3-1.2; available 0.01-0.05), Cu (total 79-375; available 0.8-10) and Pb (total 95-9210; available 0.2-40) are significantly higher in mine soils than in uncontaminated soils Zn (total 92-123; available <0.6), As (total 18-20; available <0.08), Cd (total <0.3; available <0.01), Cu (total 25-47; available <0.1) and Pb (total 28-50; < available 0.08). Also, shoots and roots of the plants collected in both mine areas contain in general higher concentrations (mg/kg) of As (shoot 0.6-75; root 0.8-13.5)and Pb (shoot 2.5-35; root 1.8-91) than plants from uncontaminated soils (As (shoot 0.8-1.2; root <0.8); Pb (shoot <3.2; root 4-9)). Physiological analyses showed a decrease in chlorophylls, anthocyanins, ascorbic acid levels and percentage of glutathione in shoots of C. monspeliensis collected in contaminated areas compared to the plants growing on uncontaminated soils. The decrease in anthocyanins is correlated with the content of Cd and Zn in plants shoots. A negative correlation was observed between carotenoid contents and Cd concentration in shoots in both mine areas. Arsenic and Cd concentrations were correlated positively with an increase of glutathione in plants grown on mine soils. Moreover, high concentrations of metals in mine soils triggered defence mechanisms against oxidative stress, in the form of increased antioxidative enzyme activity. Therefore, these results reveal that C. monspeliensis is a species adapted to unfavourable environments with high concentrations of metal(loid)s, adjusting its tolerance mechanisms at the metabolic and physiological levels.

The role of phytoplankton in the modulation of dissolved and oyster cadmium concentrations in Deep Bay, British Columbia, Canada.

PubMed

Cassis, David; Lekhi, Priyanka; Pearce, Christopher M; Ebell, Nadene; Orians, Kristin; Maldonado, Maria T

2011-09-15

We previously identified dissolved cadmium (Cd(diss)) as the main source of this metal in cultured Pacific oysters, Crassostrea gigas, in Deep Bay, British Columbia, Canada (Lekhi et al., 2008). Total suspended particulate Cd (Cd(part)) was not found to be a significant source of oyster Cd (Cd(oys)), with Cd(part) >20 μm negatively correlated with Cd(oys) concentration. High phytoplankton abundance in spring and summer was hypothesized to reduce Cd(oys) indirectly by drawing down Cd(diss) and increasing oyster growth. In the present study we expanded on these results by examining specifically how the phytoplankton community composition modulates both Cd(diss) and Cd(oys) concentrations in Deep Bay. Based on calculations of nutrients and Cd(diss) drawdown, phytoplankton accounted for approximately 90% of the overall summer reduction in Cd(diss) in the bay. Diatoms were the dominant phytoplankton group, being correlated negatively with Cd(oys) and positively with Cd(part). This suggests that diatom growth mediates the transfer of Cd from the dissolved to the particulate phase, resulting in lower Cd(oys). Spring blooms and sporadic harmful algal blooms may mediate a large flux of Cd(part) to the sediments. Thus, phytoplankton act as a sink, rather than a source, of Cd to oysters in Deep Bay and have a crucial role in the seasonality of Cd(oys) by reducing the concentration of Cd(diss) during the summer. Based on environmental variables, two descriptive models for annual Cd(oys) concentrations were developed using multiple linear regression. The first model (R(2)=0.870) was created to explain the maximum variability in Cd(oys) concentrations throughout the year, while the second (R(2)=0.806) was based on parameters that could be measured easily under farm conditions. Oyster age heavily affected both models, with the first model being secondarily affected by temperature and the second one being more sensitive to changes in salinity. Copyright © 2011 Elsevier B.V. All rights reserved.

Estimation of Cadmium uptake by tobacco plants from laboratory leaching tests.

PubMed

Marković, Jelena P; Jović, Mihajlo D; Smičiklas, Ivana D; Šljivić-Ivanović, Marija Z; Smiljanić, Slavko N; Onjia, Antonije E; Popović, Aleksandar R

2018-03-21

The objective of the present study was to determine the impact of cadmium (Cd) concentration in the soil on its uptake by tobacco plants, and to compare the ability of diverse extraction procedures for determining Cd bioavailability and predicting soil-to-plant transfer and Cd plant concentrations. The pseudo-total digestion procedure, modified Tessier sequential extraction and six standard single-extraction tests for estimation of metal mobility and bioavailability were used for the leaching of Cd from a native soil, as well as samples artificially contaminated over a wide range of Cd concentrations. The results of various leaching tests were compared between each other, as well as with the amounts of Cd taken up by tobacco plants in pot experiments. In the native soil sample, most of the Cd was found in fractions not readily available under natural conditions, but with increasing pollution level, Cd amounts in readily available forms increased. With increasing concentrations of Cd in the soil, the quantity of pollutant taken up in tobacco also increased, while the transfer factor (TF) decreased. Linear and non-linear empirical models were developed for predicting the uptake of Cd by tobacco plants based on the results of selected leaching tests. The non-linear equations for ISO 14870 (diethylenetriaminepentaacetic acid extraction - DTPA), ISO/TS 21268-2 (CaCl 2 leaching procedure), US EPA 1311 (toxicity characteristic leaching procedure - TCLP) single step extractions, and the sum of the first two fractions of the sequential extraction, exhibited the best correlation with the experimentally determined concentrations of Cd in plants over the entire range of pollutant concentrations. This approach can improve and facilitate the assessment of human exposure to Cd by tobacco smoking, but may also have wider applicability in predicting soil-to-plant transfer.

The Evaluation on the Cadmium Net Concentration for Soil Ecosystems.

PubMed

Yao, Yu; Wang, Pei-Fang; Wang, Chao; Hou, Jun; Miao, Ling-Zhan

2017-03-12

Yixing, known as the "City of Ceramics", is facing a new dilemma: a raw material crisis. Cadmium (Cd) exists in extremely high concentrations in soil due to the considerable input of industrial wastewater into the soil ecosystem. The in situ technique of diffusive gradients in thin film (DGT), the ex situ static equilibrium approach (HAc, EDTA and CaCl2), and the dissolved concentration in soil solution, as well as microwave digestion, were applied to predict the Cd bioavailability of soil, aiming to provide a robust and accurate method for Cd bioavailability evaluation in Yixing. Moreover, the typical local cash crops-paddy and zizania aquatica-were selected for Cd accumulation, aiming to select the ideal plants with tolerance to the soil Cd contamination. The results indicated that the biomasses of the two applied plants were sufficiently sensitive to reflect the stark regional differences of different sampling sites. The zizania aquatica could effectively reduce the total Cd concentration, as indicated by the high accumulation coefficients. However, the fact that the zizania aquatica has extremely high transfer coefficients, and its stem, as the edible part, might accumulate large amounts of Cd, led to the conclusion that zizania aquatica was not an ideal cash crop in Yixing. Furthermore, the labile Cd concentrations which were obtained by the DGT technique and dissolved in the soil solution showed a significant correlation with the Cd concentrations of the biota accumulation. However, the ex situ methods and the microwave digestion-obtained Cd concentrations showed a poor correlation with the accumulated Cd concentration in plant tissue. Correspondingly, the multiple linear regression models were built for fundamental analysis of the performance of different methods available for Cd bioavailability evaluation. The correlation coefficients of DGT obtained by the improved multiple linear regression model have not significantly improved compared to the coefficients obtained by the simple linear regression model. The results revealed that DGT was a robust measurement, which could obtain the labile Cd concentrations independent of the physicochemical features' variation in the soil ecosystem. Consequently, these findings provide stronger evidence that DGT is an effective and ideal tool for labile Cd evaluation in Yixing.

The Evaluation on the Cadmium Net Concentration for Soil Ecosystems

PubMed Central

Yao, Yu; Wang, Pei-Fang; Wang, Chao; Hou, Jun; Miao, Ling-Zhan

2017-01-01

Yixing, known as the “City of Ceramics”, is facing a new dilemma: a raw material crisis. Cadmium (Cd) exists in extremely high concentrations in soil due to the considerable input of industrial wastewater into the soil ecosystem. The in situ technique of diffusive gradients in thin film (DGT), the ex situ static equilibrium approach (HAc, EDTA and CaCl2), and the dissolved concentration in soil solution, as well as microwave digestion, were applied to predict the Cd bioavailability of soil, aiming to provide a robust and accurate method for Cd bioavailability evaluation in Yixing. Moreover, the typical local cash crops—paddy and zizania aquatica—were selected for Cd accumulation, aiming to select the ideal plants with tolerance to the soil Cd contamination. The results indicated that the biomasses of the two applied plants were sufficiently sensitive to reflect the stark regional differences of different sampling sites. The zizania aquatica could effectively reduce the total Cd concentration, as indicated by the high accumulation coefficients. However, the fact that the zizania aquatica has extremely high transfer coefficients, and its stem, as the edible part, might accumulate large amounts of Cd, led to the conclusion that zizania aquatica was not an ideal cash crop in Yixing. Furthermore, the labile Cd concentrations which were obtained by the DGT technique and dissolved in the soil solution showed a significant correlation with the Cd concentrations of the biota accumulation. However, the ex situ methods and the microwave digestion-obtained Cd concentrations showed a poor correlation with the accumulated Cd concentration in plant tissue. Correspondingly, the multiple linear regression models were built for fundamental analysis of the performance of different methods available for Cd bioavailability evaluation. The correlation coefficients of DGT obtained by the improved multiple linear regression model have not significantly improved compared to the coefficients obtained by the simple linear regression model. The results revealed that DGT was a robust measurement, which could obtain the labile Cd concentrations independent of the physicochemical features’ variation in the soil ecosystem. Consequently, these findings provide stronger evidence that DGT is an effective and ideal tool for labile Cd evaluation in Yixing. PMID:28287500

Integrated Assessment of Heavy Metal Pollution in the Surface Sediments of the Laizhou Bay and the Coastal Waters of the Zhangzi Island, China: Comparison among Typical Marine Sediment Quality Indices

PubMed Central

Zhuang, Wen; Gao, Xuelu

2014-01-01

The total concentrations and chemical forms of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the surface sediments of the Laizhou Bay and the surrounding marine area of the Zhangzi Island (hereafter referred to as Zhangzi Island for short) were obtained and multiple indices and guidelines were applied to assess their contamination and ecological risks. The sedimentary conditions were fine in both of the two studied areas according to the marine sediment quality of China. Whereas the probable effects level guideline suggested that Ni might cause adverse biological effects to occur frequently in some sites. All indices used suggested that Cd posed the highest environmental risk in both the Laizhou Bay and the Zhangzi Island, though Cd may unlikely be harmful to human and ecological health due to the very low total concentrations. The enrichment factor (EF) showed that a substantial portion of Cr was delivered from anthropogenic sources, whereas the risk assessment code (RAC) indicated that most Cr was in an inactive state that it may not have any adverse effect either. Moreover, the results of EF and geoaccumulation index were consistent with the trend of the total metal concentrations except for Cd, while the results of RAC and potential ecological risk factor did not follow the same trend of their corresponding total metal concentrations. We also evaluated the effects of using different indices to assess the environmental impact of these heavy metals. PMID:24709993

Cadmium accumulation and tolerance of Lagerstroemia indica and Lagerstroemia fauriei (Lythraceae) seedlings for phytoremediation applications.

PubMed

Wang, Yixiang; Gu, Cuihua; Bai, Shangbin; Sun, Zhibin; Zhu, Tingting; Zhu, Xudan; Grit, Dale H; Tembrock, Luke R

2016-11-01

Contamination by heavy metals is one of the most serious environmental problems generated from human activities. Because phytoremediation utilizes plants to uptake contaminants, it could potentially be used to remediate metal-contaminated areas. A pot culture experiment with four levels of cadmium (Cd) (0, 20, 40, and 80 mg of Cd/kg dry soil) was conducted to investigate Cd accumulation and tolerance of roots, shoots, and leaves of Lagerstroemia indica and Lagerstroemia fauriei as well as their potential for phytoremediation. Experimental results indicated that Cd inhibited seedling growth only at the higher Cd exposure concentration (40 and 80 mg/kg). The tolerance index revealed that on average L. indica is more tolerant of Cd than L. fauriei. Moreover, plants in the experiment accumulated Cd differentially. In comparisons between L. indica and L. fauriei, the leaves of the former had higher concentrations of Cd, while the roots of latter had higher concentrations of Cd. Furthermore, the roots, shoots, and leaves had very high bioaccumulation factors that markedly exceeded 1.0 (exceptional only in shoots of 80 mg/kg for L. fauriei), indicating that the seedlings extracted Cd from the soil. The leaves' translocation factor of L. indica was greater than 1.0, being significantly higher than that of L. fauriei. Chlorophyll a, Chlorophyll b and total declined in both species significantly as Cd concentrations exceeded 40 mg/kg in the soil. In contrast, lipid peroxidation and proline content was found to increase with increasing Cd concentration. From the assessments of biomass production, Cd tolerance and uptake L. indica and L. fauriei could stand as excellent species for remediating Cd-contaminated soils.

Increased concentrations of soluble CD40 ligand platelet in patients with primary antiphospholipidic syndrome.

PubMed

Galicia López, Aida; Olguín Ortega, Lourdes; Saavedra, Miguel A; Méndez Cruz, René; Jimenez Flores, Rafael; García de la Peña, Maximiliano

2013-01-01

To determine the concentrations of sCD40L in patients with PAPS, and establish its association with the number of thrombosis. We included patients with PAPS and healthy controls of the same age and sex. For analysis, patients with PAPS were divided into 2 groups: 1) patients with 1 thrombosis, and 2) patients with >1 thrombosis. Soluble CD40L concentrations were determined by ELISA method. sCD40L concentrations were significantly higher in patients with PAPS compared with the controls (9.72 ng ± 11.23 ng/ml vs. 4.69 ± 4.04 ng/ml) (P=.04) There was no association between serum levels of sCD40L and the number of thrombosis (1 thrombosis: 9.81 ± 9.87 ng/ml vs 9.63 ± 12.75 ng/ml in ≥ 1thrombosis (P=.13). In women with pregnancy and abortions, (13 patients) concentrations of sCD40L were higher than in those patients without a history of abortion (26 patients) but without statically significant difference (12.11 ± 16.46 ng/ml vs. 8.80 ± 8.61 ng/ml) (P=.33). There was no correlation between levels of sCD40L and the total number of thrombosis. Patients with PAPS have higher concentrations of sCD40L compared with healthy subjects, although this is not associated with a greater number of thrombosis. Among patients with PAPS, there is a tendency to higher concentrations of sCD40L in women with pregnancy and history of abortion. Since the platelet is the main cellular source of sCD40L, is possible that this pathway plays a pathogenic role in patients with PAPS. Copyright © 2012 Elsevier España, S.L. All rights reserved.

The effects of cadmium pulse dosing on physiological traits and growth of the submerged macrophyte Vallisneria spinulosa and phytoplankton biomass: a mesocosm study.

PubMed

Liu, Hui; Cao, Yu; Li, Wei; Zhang, Zhao; Jeppesen, Erik; Wang, Wei

2017-06-01

Pulse inputs of heavy metals are expected to increase with a higher frequency of extreme climate events (heavy rain), leading to stronger erosion of contaminated and fertilized farmland soils to freshwaters, with potentially adverse effects on lake ecosystems. We conducted a 5-month mesocosm study to elucidate the responses of the submerged macrophyte Vallisneria spinulosa and phytoplankton to four different doses of cadmium (Cd): 0 (control), 0.05, 0.5, and 5 g m -2 (CK, I, II, and III, respectively) under mesotrophic conditions. We found that total phosphorus concentrations were larger in the three Cd pulse treatments, whereas total nitrogen concentrations did not differ among the four treatments. The contents of chlorophyll a and soluble sugar in macrophyte leaves decreased in III, and total biomass, ramet number, plant height, and total stolon length of macrophytes were lower in both II and III. In contrast, abundances of the three main phytoplankton taxa-Cyanophyta, Chlorophyta, and Bacillariophyta-did not differ among treatments. Total phytoplankton biomass was, however, marginally lower in CK than in the Cd treatments. We conclude that exposure to strong Cd pulses led to significantly reduced growth of macrophytes, while no obvious effect appeared for phytoplankton.

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in soils of different land uses in Erbil metropolis, Kurdistan Region, Iraq.

PubMed

Amjadian, Keyvan; Sacchi, Elisa; Rastegari Mehr, Meisam

2016-11-01

Urban soil contamination is a growing concern for the potential health impact on the increasing number of people living in these areas. In this study, the concentration, the distribution, the contamination levels, and the role of land use were investigated in Erbil metropolis, the capital of Iraqi Kurdistan. A total of 74 soil samples were collected, treated, and analyzed for their physicochemical properties, and for 7 heavy metals (As, Cd, Cr, Cu, Fe, Pb, and Zn) and 16 PAH contents. High concentrations, especially of Cd, Cu Pb, and Zn, were found. The Geoaccumulation index (I geo ), along with correlation coefficients and principal component analysis (PCA) showed that Cd, Cu, Pb, and Zn have similar behaviors and spatial distribution patterns. Heavy traffic density mainly contributed to the high concentrations of these metals. The total concentration of ∑PAHs ranged from 24.26 to 6129.14 ng/g with a mean of 2296.1 ng/g. The PAH pattern was dominated by 4- and 5-ring PAHs, while diagnostic ratios and PCA indicated that the main sources of PAHs were pyrogenic. The toxic equivalent (TEQ) values ranged from 3.26 to 362.84 ng/g, with higher values in central parts of the city. A statistically significant difference in As, Cd, Cu, Pb, Zn, and ∑PAH concentrations between different land uses was observed. The highest As concentrations were found in agricultural areas while roadside, commercial, and industrial areas had the highest Cd, Cu, Pb, Zn, and ∑PAH contents.

Predicting As, Cd, Cu, Pb and Zn levels in grasses (Agrostis sp. and Poa sp.) and stinging nettle (Urtica dioica) applying soil-plant transfer models.

PubMed

Boshoff, Magdalena; De Jonge, Maarten; Scheifler, Renaud; Bervoets, Lieven

2014-09-15

The aim of this study was to derive regression-based soil-plant models to predict and compare metal(loid) (i.e. As, Cd, Cu, Pb and Zn) concentrations in plants (grass Agrostis sp./Poa sp. and nettle Urtica dioica L.) among sites with a wide range of metal pollution and a wide variation in soil properties. Regression models were based on the pseudo total (aqua-regia) and exchangeable (0.01 M CaCl2) soil metal concentrations. Plant metal concentrations were best explained by the pseudo total soil metal concentrations in combination with soil properties. The most important soil property that influenced U. dioica metal concentrations was the clay content, while for grass organic matter (OM) and pH affected the As (OM) and Cu and Zn (pH). In this study multiple linear regression models proved functional in predicting metal accumulation in plants on a regional scale. With the proposed models based on the pseudo total metal concentration, the percentage of variation explained for the metals As, Cd, Cu, Pb and Zn were 0.56%, 0.47%, 0.59%, 0.61%, 0.30% in nettle and 0.46%, 0.38%, 0.27%, 0.50%, 0.28% in grass. Copyright © 2014 Elsevier B.V. All rights reserved.

Responses of soil microbial activity to cadmium pollution and elevated CO2.

PubMed

Chen, Yi Ping; Liu, Qiang; Liu, Yong Jun; Jia, Feng An; He, Xin Hua

2014-03-06

To address the combined effects of cadmium (Cd) and elevated CO2 on soil microbial communities, DGGE (denaturing gradient gel electrophoresis) profiles, respiration, carbon (C) and nitrogen (N) concentrations, loessial soils were exposed to four levels of Cd, i.e., 0 (Cd0), 1.5 (Cd1.5), 3.0 (Cd3.0) and 6.0 (Cd6.0) mg Cd kg(-1) soil, and two levels of CO2, i.e., 360 (aCO2) and 480 (eCO2) ppm. Compared to Cd0, Cd1.5 increased fungal abundance but decreased bacterial abundance under both CO2 levels, whilst Cd3.0 and Cd6.0 decreased both fungal and bacterial abundance. Profiles of DGGE revealed alteration of soil microbial communities under eCO2. Soil respiration decreased with Cd concentrations and was greater under eCO2 than under aCO2. Soil total C and N were greater under higher Cd. These results suggest eCO2 could stimulate, while Cd pollution could restrain microbial reproduction and C decomposition with the restraint effect alleviated by eCO2.

Comparison of the Health Implications on the Use of As and Cd Contaminated Water Supply between Urban and Rural Communities

PubMed Central

Zailina, H.; Najibah, H.; Nadia Aiezzati, A.; Praveena, S. M.; Patimah, I.

2014-01-01

A cross-sectional study was carried out to determine the arsenic (As) and cadmium (Cd) concentrations in blood, urine, and drinking water as well as the health implications on 100 residents in an urban and a rural community. Results showed the blood As, urinary Cd, DNA damage, and water As and Cs were significantly (P < 0.001) higher in the rural community. Findings showed significant (P < 0.005) correlations between blood As and DNA damage with household income, years of residence, and total glasses of daily water consumption among the rural residents. The urinary NAG concentrations, years of residence, milk powder intake (glass/week), and seafood intake (per week) were significantly correlated (P < 0.005) with urinary Cd concentrations among respondents. In addition, urinary Cd level significantly influenced the urinary NAG concentrations (P < 0.001). The rural respondents experienced significantly higher lymphocyte DNA damage and blood As influenced by their years of residence and water consumption. The Cd in drinking water also resulted in the rural respondents having significantly higher urinary NAG which had a significant relationship with urinary Cd. PMID:25530970

Cadmium stress alters the redox reaction and hormone balance in oilseed rape (Brassica napus L.) leaves.

PubMed

Yan, Hui; Filardo, Fiona; Hu, Xiaotao; Zhao, Xiaomin; Fu, DongHui

2016-02-01

In order to understand the physiological response of oilseed rape (Brassica napus L.) leaves to cadmium (Cd) stress and exploit the physiological mechanisms involved in Cd tolerance, macro-mineral and chlorophyll concentrations, reactive oxygen species (ROS) accumulation, activities of enzymatic antioxidants, nonenzymatic compounds metabolism, endogenous hormonal changes, and balance in leaves of oilseed rape exposed to 0, 100, or 200 μM CdSO4 were investigated. The results showed that under Cd exposure, Cd concentrations in the leaves continually increased while macro-minerals and chlorophyll concentrations decreased significantly. Meanwhile, with increased Cd stress, superoxide anion (O2(• -)) production rate and hydrogen peroxide (H2O2) concentrations in the leaves increased significantly, which caused malondialdehyde (MDA) accumulation and oxidative stress. For scavenging excess accumulated ROS and alleviating oxidative injury in the leaves, the activity of enzymatic antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), was increased significantly at certain stress levels. However, with increased Cd stress, the antioxidant enzyme activities all showed a trend towards reduction. The nonenzymatic antioxidative compounds, such as proline and total soluble sugars, accumulated continuously with increased Cd stress to play a long-term role in scavenging ROS. In addition, ABA levels also increased continuously with Cd stress while ZR decreased and the ABA/ZR ratio increased, which might also be providing a protective role against Cd toxicity.

A two-year field study of phytoremediation using Solanum nigrum L. in China.

PubMed

Ji, Puhui; Song, Yufang; Jiang, Yongji; Tang, Xiwang; Tong, Yan'an; Gao, Pengcheng; Han, Wenshe

2016-09-01

A two-year in-situ phytoremediation trial was launched in Shenyang Zhangshi (Sewage) Irrigation Area (SZIA). The phytoremediation efficiency of Solanum nigrum L. was determined, by both monitoring the change of soil Cadmium level in the upper 20 cm of soil, and calculating the plant uptake of soil Cd. After two years experimental, by monitoring the soil Cd concentrations, The Cd concentrations decreased on average from 2.75 mg kg(-1)to 2.45 mg kg(-1) in the first year and from 2.33 mg kg(-1) to 1.53 mg kg(-1) in the second year, amounting to a decrease by a factor of 10.6% in the first year and 12% in the second year. After two years phytoremediation by S. nigrum, Cd concentrations of the seven experimental plots with S. nigrum growth decreased from 2.75 mg kg(-1) to 1.53 mg kg(-1), a decrease by a factor of 24.9%. And the soil Cd concentration decreased only 2.1% and 1.7% in the bared experimental plot. And the calculating of Cd uptake by S. nigrum shown that, the plants uptake 4.46% and 5.18% of the total soil Cd in 2008 and 2009, while the soil Cd concentrations decreased by a factor of 10.6% in 2008 and 12.1% in 2009.

Exotic Earthworms Decrease Cd, Hg, and Pb Pools in Upland Forest Soils of Vermont and New Hampshire USA.

PubMed

Richardson, J B; Görres, J H; Friedland, A J

2017-10-01

Exotic earthworms are present in the forests of northeastern USA, yet few studies have documented their effects on pollutant metals in soil. The objective of this study was to identify if Cd, Hg, and Pb strong-acid extractable concentrations and pools (bulk inventories) in forest soils decreased with the presence of exotic earthworms. We compared 'Low Earthworm Abundance' (LEA) sites (≤10 g m -2 earthworms, n = 13) and 'High Earthworm Abundance' (HEA) (>10 g m -2 earthworms, n = 17) sites at five watersheds across Vermont and New Hampshire. Organic horizon Cd, Hg, and Pb concentrations were lower at HEA than LEA sites. Organic horizon and total soil pools of Cd and Hg were negatively correlated with earthworm biomass. Soil profile Cd and Hg concentrations were lower at HEA than LEA sites. Our results suggest earthworms are decreasing accumulation of Cd, Hg, and Pb in forest soils, potentially via greater mobilization through organic matter disruption or bioaccumulation.

Oral bioaccessibility and human exposure assessment of cadmium and lead in market vegetables in the Pearl River Delta, South China.

PubMed

Zhuang, Ping; Li, Yingwen; Zou, Bi; Su, Feng; Zhang, Chaosheng; Mo, Hui; Li, Zhian

2016-12-01

A systematic investigation into cadmium (Cd) and lead (Pb) concentrations and their oral bioaccessibility in market vegetables in the Pearl River Delta region were carried out to assess their potential health risks to local residents. The average concentrations of Cd and Pb in six species of fresh vegetables varied within 0.09-37.7 and 2.3-43.4 μg kg -1 , respectively. Cadmium and Pb bioaccessibility were 35-66 % and 20-51 % in the raw vegetables, respectively, and found to be significantly higher than the cooked vegetables with 34-64 % for Cd and 11-48 % for Pb. The results indicated that Cd bioaccessibility was higher in the gastric phase and Pb bioaccessibility was higher in the small intestinal phase (except for fruit vegetables). Cooking slightly reduced the total concentrations and bioaccessibility of Cd and Pb in all vegetables. The bioaccessible estimated daily intakes of Cd and Pb from vegetables were far below the tolerable limits.

High variation of individual soluble serum CD30 levels of pre-transplantation patients: sCD30 a feasible marker for prediction of kidney allograft rejection?

PubMed

Altermann, Wolfgang; Schlaf, Gerald; Rothhoff, Anita; Seliger, Barbara

2007-10-01

Previous studies have suggested that the pre-transplant levels of the soluble CD30 molecule (sCD30) represent a non-invasive tool which can be used as a biomarker for the prediction of kidney allograft rejections. In order to evaluate the feasibility of sCD30 for pre-transplantation monitoring the sera of potential kidney recipients (n = 652) were collected four times in a 3 months interval. Serum from healthy blood donors (n = 203) served as controls. The sCD30 concentrations of all samples were determined using a commercially available ELISA. This strategy allowed the detection of possible variations of individual sCD30 levels over time. Heterogeneous sCD30 concentrations were found in the samples obtained from individual putative kidney transplant recipients when quarterly measured over 1 year. Total 95% of serum samples obtained from healthy controls exhibited sCD30 values <30 U/ml, whereas most recipients displayed higher serum levels (>30 U/ml). Total 524 patients (80.4%) constantly exhibited serum concentrations of <100 U/ml during the period investigated, whereas 109 patients (16.7%) showed variations by exceeding the proposed 'cut off' of 100 U/ml for one to three times. The frequency of samples exhibiting sCD30 values >100 U/ml was significantly lower than that previously reported. The high degree of variation does not allow the stratification of patients into high and low immunological risk groups based on a single sCD30 value > 100 U/ml. Due to the heterogeneity of sCD30 levels during time course and the high values of SD, its implementation as a pre-transplant marker cannot be justified to generate special provisions for the organ allocation to patients with single sCD30 values > 100 U/ml.

Optimization of β-cyclodextrin-based flavonol extraction from apple pomace using response surface methodology.

PubMed

Parmar, Indu; Sharma, Sowmya; Rupasinghe, H P Vasantha

2015-04-01

The present study investigated five cyclodextrins (CDs) for the extraction of flavonols from apple pomace powder and optimized β-CD based extraction of total flavonols using response surface methodology. A 2(3) central composite design with β-CD concentration (0-5 g 100 mL(-1)), extraction temperature (20-72 °C), extraction time (6-48 h) and second-order quadratic model for the total flavonol yield (mg 100 g(-1) DM) was selected to generate the response surface curves. The optimal conditions obtained were: β-CD concentration, 2.8 g 100 mL(-1); extraction temperature, 45 °C and extraction time, 25.6 h that predicted the extraction of 166.6 mg total flavonols 100 g(-1) DM. The predicted amount was comparable to the experimental amount of 151.5 mg total flavonols 100 g(-1) DM obtained from optimal β-CD based parameters, thereby giving a low absolute error and adequacy of fitted model. In addition, the results from optimized extraction conditions showed values similar to those obtained through previously established solvent based sonication assisted flavonol extraction procedure. To the best of our knowledge, this is the first study to optimize aqueous β-CD based flavonol extraction which presents an environmentally safe method for value-addition to under-utilized bio resources.

Occurrence of selected trace metals and their oral bioaccessibility in urban soils of kindergartens and parks in Bratislava (Slovak Republic) as evaluated by simple in vitro digestion procedure.

PubMed

Hiller, Edgar; Mihaljevič, Martin; Filová, Lenka; Lachká, Lucia; Jurkovič, Ľubomír; Kulikova, Tatsiana; Fajčíková, Katarína; Šimurková, Mária; Tatarková, Veronika

2017-10-01

A total of eighty surface soil samples were collected from public kindergartens and urban parks in the city of Bratislava, and the <150µm soil fraction was evaluated for total concentrations of five metals, Cd, Cu, Hg, Pb and Zn, their oral bioaccessibilities, non-carcinogenic and carcinogenic health risks to children, and lead isotopic composition. The mean metal concentrations in urban soils (0.29, 36.1, 0.13, 30.9 and 113mg/kg for Cd, Cu, Hg, Pb and Zn, respectively) were about two times higher compared with background soil concentrations. The order of bioaccessible metal fractions determined by Simple Bioaccessibility Extraction Test was: Pb (59.9%) > Cu (43.8%) > Cd (40.8%) > Zn (33.6%) > Hg (12.8%). Variations in the bioaccessible metal fractions were mainly related to the total metal concentrations in urban soils. A relatively wide range of lead isotopic ratios in urban soils (1.1598-1.2088 for 206 Pb/ 207 Pb isotopic ratio) indicated a combination of anthropogenic and geogenic sources of metals in the soils. Lower values of 206 Pb/ 207 Pb isotopic ratio in the city centre and similar spatial distribution of total metal concentrations, together with their increasing total concentrations in soils towards the city centre, showed that traffic and coal combustion in former times were likely the major sources of soil contamination. The non-carcinogenic and carcinogenic health risks to children due to exposure to metals in kindergarten and urban park soils were low, with hazard index and cancer risk values below the threshold values at all studied sites. Copyright © 2017 Elsevier Inc. All rights reserved.

Detection of copper, lead, cadmium and iron in wine using electronic tongue sensor system.

PubMed

Simões da Costa, A M; Delgadillo, I; Rudnitskaya, A

2014-11-01

An array of 10 potentiometric chemical sensors has been applied to the detection of total Fe, Cu, Pb and Cd content in digested wine. As digestion of organic matter of wine is necessary prior to the trace metal detection using potentiometric sensors, sample preparation procedures have been optimized. Different variants of wet and microwave digestion and dry ashing, 14 conditions in total, have been tested. Decomposition of organic matter was assessed using Fourier transform mid-infrared spectroscopy and total phenolic content. Dry ashing was found to be the most effective method of wine digestion. Measurements with sensors in individual solutions of Fe(III), Cu(II), Pb(II) and Cd(II) prepared on different backgrounds have shown that their detection limits were below typical concentration levels of these metals in wines and, in the case of Cu, Pb and Cd below maximum allowed concentrations. Detection of Fe in digested wine samples was possible using discrete iron-sensitive sensors with chalcogenide glass membranes with RMSEP of 0.05 mmol L(-1) in the concentration range from 0.0786 to 0.472 mmol L(-1). Low concentration levels of Cu, Pb and Cd in wine and cross-sensitivity of respective sensors resulted in the non-linearity of their responses, requiring back-propagation neural network for the calibration. Calibration models have been calculated using measurements in the model mixed solutions containing all three metals and a set of digested wine sample. RMSEP values for Cu, Pb and Cd were 3.9, 39 and 1.2 μmol L(-1) in model solutions and 2, 150 and 1 μmol L(-1) in digested wine samples. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of EDTA on Helianthus annuus uptake, selectivity, and translocation of heavy metals when grown in Ohio, New Mexico and Colombia soils.

PubMed

Turgut, Cafer; Pepe, M Katie; Cutright, Teresa J

2005-02-01

The use of two EDTA concentrations for enhancing the bioavailability of cadmium, chromium, and nickel in three natural soils (Ohio, New Mexico and Colombia) was investigated. The resulting uptake, translocation and selectivity with Helianthus annuus after mobilization were also examined. In general, plants grown in the sandy-loam Ohio soil had a higher uptake that resulted in a selectivity and total metal content of Cd>Cr>Ni and 0.73 mg and Cr>Cd>Ni and 0.32 mg for 0.1 and 0.3 g kg-1 EDTA, respectively. With the silty-loam New Mexico soil, although the total metal uptake was not statistically different the EDTA level did alter the selectivity; Cd>Cr>Ni (0.1 g kg-1 EDTA) and Cd>Cr>Ni (0.3 g kg-1 EDTA). Conversely, with the Colombian (sandy clay loam) soil increasing the EDTA level resulted in a higher total metal uptake (0.62 mg) than the 0.1 g kg-1 (0.59 mg) treatment. For all three soils, the translocation of Cd was limited. Evaluating the mobile metal fraction with and without EDTA determined that the chelator was capable of overcoming mass transfer limitations associated with the expandable clay fraction in the soils. Root wash results and root biomass concentrations indicated that Cd sorption was occurring. Therefore limited Cd translocation was attributed to insufficient phytochelatin levels.

Nitrogen fertilizer enhances growth and nutrient uptake of Medicago sativa inoculated with Glomus tortuosum grown in Cd-contaminated acidic soil.

PubMed

Liu, Mohan; Sun, Jian; Li, Yang; Xiao, Yan

2017-01-01

This study aimed to explore whether nitrogen availability could influence mycorrhizal function and their associations with host plants in Cd-contaminated acidic soils or not. A greenhouse pot experiment was conducted to assess the effects of mycorrhizal inoculation (non-mycorrhizal inoculation (NM), Glomus aggregatum (Ga), G. tortuosum (Gt) and G. versiforme (Gv)) and inorganic N amendment on the growth, nutrient and Cd uptake of Medicago sativa grown in Cd-contaminated acidic soils (10 mg Cd kg -1 soil). AMF inoculations significantly increased the shoot and total biomass and decreased the shoot Cd concentration in comparison to plants uninoculated. N addition increased markedly concentration and content of N and decreased those of P in plants at all inoculation treatments. Shoot K, Na and Mg concentration in plants inoculated with Ga and Gv were decreased by N addition, whereas shoot K, Na, Ca and Mg concentration in plants inoculated with Gt were not negatively affected. It was observed that N addition only increased mycorrhizal colonization, shoot biomass, shoot K, Ca and Mg content of plants inoculated with Gt. Irrespective of N addition, plants with Gt inoculation got the maximum shoot and root P concentration and content, as well as P/Cd concentration molar ratio among all inoculation treatment. Neither AMF nor N fertilizer contributed to the decrease of soil exchangeable Cd and increase of soil pH. These results suggested that N fertilizer only elevated plant performance of alfalfa with Gt inoculation grown in acidic soil, by diluting Cd concentration and alleviating of nutrient deficiency, especially P. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effects of age on associations between markers of HIV progression and markers of metabolic function including albumin, haemoglobin and lipid concentrations.

PubMed

Samuel, M; Jose, S; Winston, A; Nelson, M; Johnson, M; Chadwick, D; Fisher, M; Leen, C; Gompels, M; Gilson, R; Post, F A; Hay, P; Sabin, C A

2014-05-01

We investigated whether age modified associations between markers of HIV progression, CD4 T lymphocyte count and HIV RNA viral load (VL), and the following markers of metabolic function: albumin, haemoglobin, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). A retrospective analysis of data from the United Kingdom Collaborative HIV Cohort was carried out. Analyses were limited to antiretroviral-naïve subjects to focus on the impact of HIV disease itself. A total of 16670 subjects were included in the analysis. Multilevel linear regression models assessed associations between CD4 count/VL and each of the outcomes. Statistical tests for interactions assessed whether associations differed among age groups. After adjustment for gender and ethnicity, there was evidence that lower CD4 count and higher VL were associated with lower TC, LDL-C, haemoglobin and albumin concentrations but higher triglyceride concentrations. Age modified associations between CD4 count and albumin (P < 0.001) and haemoglobin (P = 0.001), but not between CD4 count and HDL-C, LDL-C and TC, or VL and any outcome. Among participants aged < 30, 30-50 and > 50 years, a 50 cells/μL lower CD4 count correlated with a 2.4 [95% confidence interval (CI) 1.7-3.0], 3.6 (95% CI 3.2-4.0) and 5.1 (95% CI 4.0-6.1) g/L lower haemoglobin concentration and a 0.09 (95% CI 0.07-0.11), 0.12 (95% CI 0.11-0.13) and 0.16 (95% CI 0.13-0.19) g/L lower albumin concentration, respectively. We present evidence that age modifies associations between CD4 count and plasma albumin and haemoglobin levels. A given reduction in CD4 count was associated with a greater reduction in haemoglobin and albumin concentrations among older people living with HIV. These findings increase our understanding of how the metabolic impact of HIV is influenced by age. © 2013 The Authors. HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association.

Estimating children's exposure to toxic elements in contaminated toys and children's jewelry via saliva mobilization.

PubMed

Guney, Mert; Nguyen, Alain; Zagury, Gerald J

2014-09-19

Children's potential for exposure to potentially toxic elements in contaminated jewelry and toys via mouth contact has not yet been fully evaluated. Various toys and jewelry (metallic toys and jewelry [MJ], plastic toys, toys with paint or coating, and brittle/pliable toys; n = 32) were tested using the saliva extraction (mouthing) compartment of the DIN and RIVM bioaccessibility protocols to assess As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sb, and Se mobilization via saliva. Total concentrations of As, Cd, Cu, Ni, Pb, and Sb were found elevated in analyzed samples. Four metals were mobilized to saliva from 16 MJ in significant quantities (>1 μg for highly toxic Cd and Pb, >10 μg for Cu and Ni). Bioaccessible concentrations and hazard index values for Cd exceeded limit values, for young children between 6 mo- and 3 yr-old and according to both protocols. Total and bioaccessible metal concentrations were different and not always correlated, encouraging the use of bioaccessibility for more accurate hazard assessments. Bioaccessibility increased with increasing extraction time. Overall, the risk from exposure to toxic elements via mouthing was high only for Cd and for MJ. Further research on children's exposure to toxic elements following ingestion of toy or jewelry material is recommended.

Arsenic, Lead, and Cadmium in U.S. Mushrooms and Substrate in Relation to Dietary Exposure.

PubMed

Seyfferth, Angelia L; McClatchy, Colleen; Paukett, Michelle

2016-09-06

Wild mushrooms can absorb high quantities of metal(loid)s, yet the concentration, speciation, and localization of As, Pb, and Cd in cultivated mushrooms, particularly in the United States, are unresolved. We collected 40 samples of 12 types of raw mushrooms from 2 geographic locations that produce the majority of marketable U.S. mushrooms and analyzed the total As, Pb, and Cd content, the speciation and localization of As in select samples, and assessed the metal sources and substrate-to-fruit transfer at one representative farm. Cremini mushrooms contained significantly higher total As concentrations than Shiitake and localized the As differently; while As in Cremini was distributed throughout the fruiting body, it was localized to the hymenophore region in Shiitake. Cd was significantly higher in Royal Trumpet than in White Button, Cremini, and Portobello, while no difference was observed in Pb levels among the mushrooms. Concentrations of As, Pb, and Cd were less than 1 μg g(-1) d.w. in all mushroom samples, and the overall risk of As, Cd, and Pb intake from mushroom consumption is low in the U.S. However, higher percentages of tolerable intake levels are observed when calculating risk based on single serving-sizes or when substrate contains elevated levels of metal(loid)s.

Biodiversity variability and metal accumulation strategies in plants spontaneously inhibiting fly ash lagoon, India.

PubMed

Mukhopadhyay, Suchita; Rana, Vivek; Kumar, Adarsh; Maiti, Subodh Kumar

2017-10-01

Out of 29 plant species taken into consideration for biodiversity investigations, the present study screened out Cyperus rotundus L., Calotropis procera (Aiton) W.T. Aiton, Croton bonplandianus Baill., Eclipta prostrata (L.) L., and Vernonia cinerea (L.) Less. as the most suitable metal-tolerant plant species (high relative density and frequency) which can grow on metal-laden fly ash (FA) lagoon. Total (aqua-regia), residual (HNO 3 ) and plant available (CaCl 2 ) metal concentrations were assessed for the clean-up of metal-contaminated FA disposal site using naturally colonized plants. The total metal concentration (in mg kg -1 ) in FA followed an order of Mn (229.8) > Ni (228.4) > Zn (89.4) > Cr (61.2) > Pb (56.6) > Cu (51.5) > Co (41.9) > Cd (9.7). The HNO 3 - and CaCl 2 -extracted metals were 0.57-15.68% and 0.03-7.82% of the total metal concentration, respectively. The concentration of Ni and Cr in FA in the present study was highest among the previously studied Indian and average world power plants and Cd, Ni, and Cr were above soil toxicity limit. The variation in total, residual, and plant-available metal (single extraction) concentration indicated the presence of different proportions of metals in FA lagoon which affects the metal uptake potential of the vegetation growing on it. It has been reported that plant-available metal extractant (CaCl 2 ) is the most suitable extractant for assessment of metal transfer from soil to plant. However in the present study, Spearman's correlation showed best significant correlation between total metal concentration in FA and shoot metal concentration (r = 0.840; p < 0.01) which suggest aqua-regia as the best extractant for understanding the bioavailability and transfer of metal, and in calculation of BCF for moderately contaminated site. It can be stated that plant-available extractant is not always suitable for understanding the availability of metal, but total metal concentration can provide a better insight especially for moderate or low metal-contaminated sites. Principle component analysis revealed that all the plants showed positive correlation with Co and Cd which suggest its subsequent uptake in root and shoot. The biological indices (BCF, BAF, and TF) revealed that E. prostrata (10 mg Cd kg -1 ) and C. procera (3.5 mg Cd kg -1 ) can be utilized efficiently for the phytoextraction of Cd and phytostabilization of other potentially toxic metals (Pb, Cr, and Co) from FA lagoon. All the plants were tolerant to Pb pollution (TF > 1, BAF > 1, and BCF > 1); hence, there was a negligible translocation of Pb to the aerial tissues of these plants which shows their suitability in phytostabilization. In addition, V. cinerea accumulated elevated concentration of potentially toxic Cr (50 mg Cr kg -1 ) and Ni (67 mg Ni kg -1 ) which could also help in the phytoremediation of FA lagoon.

Elevated serum levels of soluble CD30 in patients with atopic dermatitis (AD).

PubMed

Bengtsson, A; Holm, L; Bäck, O; Fransson, J; Scheynius, A

1997-09-01

The immunopathology of AD is still unclear, but evidence for an immune response polarized towards Th2 activity has been provided. The CD30 molecule belongs to the tumour necrosis factor (TNF) receptor family and is expressed on activated T cells with a sustained expression in Th2 cells. This molecule also exists in a soluble form (sCD30). Elevated serum levels of sCD30 have been found in patients with Hodgkin's disease, chronic hepatitis B infection and HIV infection. Studies were undertaken to compare the serum levels of sCD30 in patients with AD (n=49) and healthy non-atopic controls (n=94). The presence of sCD30 was analysed with ELISA. A significantly higher concentration of sCD30 was noted in AD patients, median sCD30 level 29 U/ml (range 1-708 U/ml), compared with healthy non-atopic controls (P<0.001), where the median level was 11 U/ml with a range of 1-1042 U/ml. No correlation was found between sCD30 levels and total serum IgE, or between the AD patients' SCORAD values and concentration of sCD30. sCD30 levels were also analysed in 20 AD patients, which during ketoconazole treatment had improved their clinical scores and reduced their serum IgE and eosinophil cationic protein levels. However, no significant decrease in sCD30 levels was noted after treatment. The results show that patients with AD have elevated levels of sCD30, but without correlation to total serum IgE or disease activity.

Phytostabilization potential of two ecotypes of Vetiveria zizanioides in cadmium-contaminated soils: greenhouse and field experiments.

PubMed

Phusantisampan, Theerawut; Meeinkuirt, Weeradej; Saengwilai, Patompong; Pichtel, John; Chaiyarat, Rattanawat

2016-10-01

Soil contamination by cadmium (Cd) poses a serious environmental and public health concern. Phytoremediation, i.e., the use of plants to remove contaminants from soil, has been proposed for treatment of Cd-contaminated ecosystems. In this study, we demonstrated the potential of Vetiveria zizanioides, commonly known as vetiver, to serve as an effective phytoremediation agent. Two ecotypes, i.e., India and Sri Lanka, were grown in greenhouse pots and in the field. Soils were amended with cow manure, pig manure, bat manure, and an organic fertilizer. Among all amendments, pig manure performed best in both greenhouse and field studies in terms of increasing total V. zizanioides biomass production in both ecotypes. In both greenhouse and in the field, tissue of the Sri Lanka ecotype had higher Cd concentrations than did the India ecotype. In the greenhouse, the presence of Cd did not affect total biomass production or root dry weight. The Sri Lanka ecotype had 2.7 times greater adventitious root numbers and 3.6 times greater Cd accumulation in roots than did the India ecotype. In the field study, the Sri Lanka ecotype offers potential as an excluder species, as it accumulated Cd primarily in roots, with translocation factor values <1 and a bioconcentration coefficient for roots >1 for all experiments except for the pig manure amendment. In addition, the highest Cd concentration in the Sri Lanka ecotype root (71.3 mg kg(-1)) was consistent with highest Cd uptake (10.4 mg plant(-1)) in the cow manure treatment. The India ecotype contained lower root Cd concentrations, and Cd accumulation was slightly higher in shoots compared to roots, with translocation factor (TF) values >1. The India ecotype was therefore not considered as an excluder in the Cd-contaminated soil. With the use of excluder species combined with application of organic amendments, soil contamination by Cd may be treated by alternative remediation methods such as phytostabilization.

Effect of nanohydroxyapatite on cadmium leaching and environmental risks under simulated acid rain.

PubMed

Zhao, Chenchen; Ren, Shuxia; Zuo, Qingqing; Wang, Shutao; Zhou, Yapeng; Liu, Wei; Liang, Shuxuan

2018-06-15

Cadmium (Cd) contamination in soil is a global environmental pollution issue. Nanohydroxyapatite (NHAP) has been used in soil remediation to immobilize cadmium in contaminated soils. However, the effect of acid rain on the export of cadmium from topsoil and its behavior in deep soil and leachate is unclear. In this study, column experiments and development of parsimonious model were performed to estimate Cd leaching behavior from topsoil and environmental risk of groundwater after 0.5% NHAP remediation. Four leaching events were performed and total Cd, different fractions of Cd determined by sequential extraction procedure and pH were determined for each leaching. The results show that with the export of Cd in topsoil, the total Cd concentration in soil at different depths had the following vertical distributions: 0-5 cm > 5-10 cm > 10-15 cm > 15-20 cm. NHAP treatment increased the soil pH and decreased Cd leaching loss by 56.45% compared to the control, and the results fit the parabolic diffusion model. With sequential extraction it was observed that NHAP application increased the residual fraction of cadmium in soil. After leaching, there was a positive correlation between soil pH and Cd concentration with regards to the exchangeable, reducible, oxidizable and residual Cd fractions. The parabolic diffusion model showed that Cd-contaminated soil with NHAP remediation is harmless to humans after sufficient remediation duration, whereas the resultant concentrations from the CK treatment could be toxic. The results indicate that nanohydroxyapatite could significantly reduce the bioavailability of cadmium and the environmental risk. However, the release of Ca and P from the dissolution of NHAP should be carefully studied as this will impact the mobilization of Cd or colloid Cd, and high leaching of P may result in P-induced eutrophication risk. Copyright © 2018 Elsevier B.V. All rights reserved.

Heavy metal bioaccumulation by Miscanthus sacchariflorus and its potential for removing metals from the Dongting Lake wetlands, China.

PubMed

Yao, Xin; Niu, Yandong; Li, Youzhi; Zou, Dongsheng; Ding, Xiaohui; Bian, Hualin

2018-05-09

Bioaccumulation of five heavy metals (Cd, Cu, Mn, Pb, and Zn) in six plant organs (panicle, leaf, stem, root, rhizome, and bud) of the emergent and perennial plant species, Miscanthus sacchariflorus, were investigated to estimate the plant's potential for accumulating heavy metals in the wetlands of Dongting Lake. We found the highest Cd concentrations in the panicles and leaves; while the highest Cu and Mn were observed in the roots, the highest Pb in the panicles, and the highest Zn in the panicles and buds. In contrast, the lowest Cd concentrations were detected in the stem, roots, and buds; the lowest Cu concentrations in the leaves and stems; the lowest Mn concentrations in the panicles, rhizomes, and buds; the lowest Pb concentrations in the stems; and the lowest Zn concentrations in the leaves, stems, and rhizomes. Mean Cu concentration in the plant showed a positive regression coefficient with plot elevation, soil organic matter content, and soil Cu concentration, whereas it showed a negative regression coefficient with soil moisture and electrolyte leakage. Mean Mn concentration showed positive and negative regression coefficients with soil organic matter and soil moisture, respectively. Mean Pb concentration exhibited positive regression coefficient with plot elevation and soil total P concentration, and Zn concentration showed a positive regression coefficient with soil available P and total P concentrations. However, there was no significant regression coefficient between mean Cd concentration in the plant and the investigated environmental parameters. Stems and roots were the main organs involved in heavy metal accumulation from the environment. The mean quantities of heavy metals accumulated in the plant tissues were 2.2 mg Cd, 86.7 mg Cu, 290.3 mg Mn, 15.9 mg Pb, and 307 mg Zn per square meter. In the Dongting Lake wetlands, 0.7 × 10 3  kg Cd, 22.9 × 10 3  kg Cu, 77.5 × 10 3  kg Mn, 3.1 × 10 3  kg Pb, and 95.9 × 10 3  kg Zn per year were accumulated by aboveground organs and removed from the lake through harvesting for paper manufacture.

Complexation of cadmium to sulfur and oxygen functional groups in an organic soil

NASA Astrophysics Data System (ADS)

Karlsson, Torbjörn; Elgh-Dalgren, Kristin; Björn, Erik; Skyllberg, Ulf

2007-02-01

Cadmium (Cd) is a toxic trace element and due to human activities soils and waters are contaminated by Cd both on a local and global scale. It is widely accepted that chemical interactions with functional groups of natural organic matter (NOM) is vital for the bioavailability and mobility of trace elements. In this study the binding strength of cadmium (Cd) to soil organic matter (SOM) was determined in an organic (49% organic C) soil as a function of reaction time, pH and Cd concentration. In experiments conducted at native Cd concentrations in soil (0.23 μg g -1 dry soil), halides (Cl, Br) were used as competing ligands to functional groups in SOM. The concentration of Cd in the aqueous phase was determined by isotope-dilution (ID) inductively-coupled-plasma-mass-spectrometry (ICP-MS), and the activity of Cd 2+ was calculated from the well-established Cd-halide constants. At higher Cd loading (500-54,000 μg g -1), the Cd 2+ activity was directly determined by an ion-selective electrode (ISE). On the basis of results from extended X-ray absorption fine structure (EXAFS) spectroscopy, a model with one thiolate group (RS -) was used to describe the complexation (Cd 2+ + RS - ⇆ CdSR +; log KCdSR) at native Cd concentrations. The concentration of thiols (RSH; 0.047 mol kg -1 C) was independently determined by X-ray absorption near-edge structure (XANES) spectroscopy. Log KCdSR values of 11.2-11.6 (p Ka for RSH = 9.96), determined in the pH range 3.1-4.6, compare favorably with stability constants for the association between Cd and well-defined thiolates like glutathione. In the concentration range 500-54,000 μg Cd g -1, a model consisting of one thiolate and one carboxylate (RCOO -) gave the best fit to data, indicating an increasing role for RCOOH groups as RSH groups become saturated. The determined log KCdOOCR of 3.2 (Cd 2+ + RCOO - ⇆ CdOOCR +; log KCdOOCR; p Ka for RCOOH = 4.5) is in accordance with stability constants determined for the association between Cd and well-defined carboxylates. Given a concentration of reduced sulfur groups of 0.2% or higher in NOM, we conclude that the complexation to organic RSH groups may control the speciation of Cd in soils, and most likely also in surface waters, with a total concentration less than 5 mg Cd g -1 organic C.

Ferti-irrigational impact of sugar mill effluent on agronomical characteristics of Phaseolus vulgaris (L.) in two seasons.

PubMed

Kumar, Vinod; Chopra, A K

2014-11-01

Ferti-irrigation response of 5, 10, 25, 50, 75, and 100 % concentrations of the sugar mill effluent (SME) on French bean (Phaseolus vulgaris L., cv. Annapurna) in the rainy and summer seasons was investigated. The fertigant concentrations produced significant (P < 0.01) changes in the soil parameters, viz., electrical conductivity (EC), pH, organic carbon (OC), sodium (Na(+)), potassium (K(+)), calcium (Ca(2+)), magnesium (Mg(2+)), total Kjeldahl nitrogen (TKN), phosphate (PO4 (3-)), sulfate (SO4 (2-)), ferrous (Fe(2+)), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn), in both seasons. The contents of Cr, Cu, Mn, and Zn except Cd were found to be below the maximum levels permitted for soils in India. The agronomic performance of P. vulgaris was gradually increased at lower concentrations, i.e., from 5 to 25 %, and decreased at higher concentrations, i.e., from 50 to 100 %, of the SME in both seasons when compared to controls. The accumulations of heavy metals were increased in the soil and P. vulgaris from 5 to 100 % concentrations of the SME in both seasons. The contents of Cu, Mn, and Zn except Cd and Cr were noted under the permissible limit of Food and Agriculture Organization (FAO)/World Health Organization (WHO) standards. Most contents of biochemical components like crude proteins, crude fiber, and total carbohydrates were found with 25 % concentration of the SME in both seasons. The contamination factor (Cf) of various metals was in the order of Cd > Cr > Zn > Mn > Cu for soil and Mn > Zn > Cu > Cr > Cd for P. vulgaris in both seasons after fertigation with SME. Therefore, the SME can be used to improve the soil fertility and yield of P. vulgaris after appropriate dilution.

Trace metals accumulation in Bacopa monnieri and their bioaccessibility.

PubMed

Srikanth Lavu, Rama Venkata; Prasad, Majeti Narasimha Vara; Pratti, Varalakshmi Lalithya; Meißner, Ralph; Rinklebe, Jörg; Van De Wiele, Tom; Tack, Filip; Du Laing, Gijs

2013-08-01

Bacopa monnieri is commonly known as "Brahmi" or "Water hyssop" and is a source of nootropic drugs. Aboveground parts of plant samples collected from peri-urban Indian areas were analysed for total trace metal concentrations. Subsequently, three samples with high concentrations of Cd and Pb were subjected to in vitro gastrointestinal digestion to assess the bioaccessibility of the trace metals in these plants. The total concentrations of trace metals on a dry weight basis were 1.3 to 6.7 mg·kg⁻¹ Cd, 1.5 to 22 mg·kg⁻¹ Pb, 36 to 237 mg·kg⁻¹ Cu, and 78 to 186 mg·kg⁻¹ Zn. The majority of Bacopa monnieri samples exceeded threshold limits of Cd, Pb, Cu, and Zn for use as raw medicinal plant material or direct consumption. Therefore, it is necessary to evaluate Bacopa monnieri collected in nature for their trace metal content prior to human consumption and preparation of herbal formulations. Georg Thieme Verlag KG Stuttgart · New York.

Heavy metals in edible seaweeds commercialised for human consumption

NASA Astrophysics Data System (ADS)

Besada, Victoria; Andrade, José Manuel; Schultze, Fernando; González, Juan José

2009-01-01

Though seaweed consumption is growing steadily across Europe, relatively few studies have reported on the quantities of heavy metals they contain and/or their potential effects on the population's health. This study focuses on the first topic and analyses the concentrations of six typical heavy metals (Cd, Pb, Hg, Cu, Zn, total As and inorganic As) in 52 samples from 11 algae-based products commercialised in Spain for direct human consumption ( Gelidium spp.; Eisenia bicyclis; Himanthalia elongata; Hizikia fusiforme; Laminaria spp.; Ulva rigida; Chondrus crispus; Porphyra umbilicales and Undaria pinnatifida). Samples were ground, homogenised and quantified by atomic absorption spectrometry (Cu and Zn by flame AAS; Cd, Pb and total As by electrothermal AAS; total mercury by the cold vapour technique; and inorganic As by flame-hydride generation). Accuracy was assessed by participation in periodic QUASIMEME (Quality Assurance of Information in Marine Environmental Monitoring in Europe) and IAEA (International Atomic Energy Agency) intercalibration exercises. To detect any objective differences existing between the seaweeds' metal concentrations, univariate and multivariate studies (principal component analysis, cluster analysis and linear discriminant analysis) were performed. It is concluded that the Hizikia fusiforme samples contained the highest values of total and inorganic As and that most Cd concentrations exceeded the French Legislation. The two harvesting areas (Atlantic and Pacific oceans) were differentiated using both univariate studies (for Cu, total As, Hg and Zn) and a multivariate discriminant function (which includes Zn, Cu and Pb).

Microfiltration: Effect of channel diameter on limiting flux and serum protein removal.

PubMed

Hurt, E E; Adams, M C; Barbano, D M

2015-06-01

Our objective was to determine the limiting flux and serum protein (SP) removal at 8, 9 and 10% true protein (TP) in the retentate recirculation loop using 0.1-µm ceramic graded permeability (GP) microfiltration (MF) membranes with 3mm channel diameters (CD). An additional objective was to compare the limiting flux and SP removal between 0.1-µm ceramic GP membranes with 3mm CD and previous research using 4-mm CD membranes. The MF system was operated at 50°C, using a diluted milk protein concentrate with 85% protein on a total solids basis (MPC85) as the MF feed. The limiting flux for the MF of diluted MPC85 was determined at 8, 9, and 10% TP concentration in the recirculation loop. The experiment using the 3-mm CD membranes was replicated 3 times for a total of 9 runs. On the morning of each run MPC85 was diluted with reverse osmosis water to a MF feed TP concentration of 5.4%. In all runs the starting flux was 55 kg/m2 per hour, the flux was then increased in steps until the limiting flux was reached. For the 3-mm CD membranes, the limiting flux was 128±0.3, 109±4, and 97±0.5 kg/m2 per hour at recirculation loop TP concentrations of 8.1±0.07, 9.2±0.04, and 10.2±0.03%, respectively. For the 3-mm CD membranes, increasing the flux from the starting to the limiting flux decreased the SP removal factor from 0.72±0.02 to 0.67±0.01; however, no difference in SP removal factor among the target recirculation loop TP concentrations was detected. The limiting flux at each recirculation loop target TP concentration was lower for the 3- compared with the 4-mm CD membranes. The differences in limiting fluxes between the 3- and 4-mm CD membranes were explained in part by the difference in cross-flow velocity (5.5±0.03 and 7.0±0.03 m/s for the 3- and 4-mm CD membranes, respectively). The SP removal factor was also lower for the 3- compared with the 4-mm CD membranes, indicating that more membrane fouling may have occurred in the 3- versus 4-mm CD membranes. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A biomonitor for tracking changes in the availability of lakewater cadmium over space and time

USGS Publications Warehouse

Hare, L.; Tessier, A.; Croteau, M.-N.

2008-01-01

Determining the exposure of organisms to contaminants is a key component of Ecological Risk Assessments (ERAs). Effective estimates of exposure consider not only the total concentrations of contaminants in an organism's surroundings but also the availability of the contaminants to organisms. Contaminant availability can be inferred from mechanistic models and verified by measurements of contaminant concentrations in organisms. We evaluated the widespread lake-dwelling insect Chaoborus as a potential biomonitor for use in exposure assessments for three metals: cadmium (Cd), copper (Cu), and zinc (Zn). We show that larvae of this midge maintain constant their concentrations of the essential metals Cu and Zn and thus cannot be used to monitor them. In contrast, larval Cd concentrations varied widely both among lakes and in a given lake over time. We were able to relate these variations in biomonitor Cd to changes in lakewater Cd and pH using the Free Ion Activity Model (FIAM). Our results suggest that Chaoborus larvae could be used as an effective tool for estimating the Cd exposure of organisms in lakes for the purposes of ERAs.

Trophic transfer of Cd from duckweed (Lemna minor L.) to tilapia (Oreochromis mossambicus).

PubMed

Xue, Yan; Peijnenburg, Willie J G M; Huang, Jin; Wang, Dengjun; Jin, Yan

2018-05-01

The transfer of the toxic heavy metal Cd from duckweed (Lemna minor L.) to the freshwater fish tilapia (Oreochromis mossambicus) was investigated. Concentrations of Cd in different chemical forms in duckweed and in different tissues (gut, edible muscle, and remnants or residual) of tilapia (i.e., ethanol-extractable fraction [F E ], HCl-extractable fraction [F HCl ], and residual fraction [F R ]) were quantified, and the bioaccumulation factors (BAFs) of Cd in the tilapia body were calculated. Simple linear regression analysis was used to unravel the correlation and accumulation mechanisms of Cd along the short food chain. Our results showed that with increasing exposure concentrations of Cd (0-50 μM for duckweed and 0-10 μM for tilapia), the total, F E (F e,d )-, F HCl (F h,d )-, and F R (F r,d )-Cd concentrations in duckweed and different tissues of tilapia increased progressively. The Cd sources (aqueous or dietary) influenced the BAF for Cd accumulation in the whole body of tilapia. Furthermore, regression analyses yielded significant positive correlations (R 2 > 0.96) between the Cd concentration in duckweed and in both the 3 parts and the whole body of tilapia. This finding suggests that Cd transfer from duckweed to tilapia can be quantitatively evaluated when tilapia is exposed only to duckweed. In addition, the linear regression between Cd accumulation in whole tilapia and F e,d -, F h,d -, and F r,d -Cd showed that particularly the correlation with F e,d -Cd is statistically significant (p < 0.001). The accumulated Cd concentrations and chemical forms in tilapia tissues also positively correlated with Cd sources (solution or duckweed). Compared with waterborne exposure only, duckweed especially increased the accumulation of Cd in the gut of tilapia. Taken together, our findings support a strong dependence of Cd accumulation and transfer from duckweed to tilapia on its chemical forms, especially on F e,d -Cd. This knowledge may expedite more accurate risk assessment of heavy metals through aquatic food chain ecosystems. Environ Toxicol Chem 2018;37:1367-1377. © 2018 SETAC. © 2018 SETAC.

Study of the potential of barnyard grass for the remediation of Cd- and Pb-contaminated soil.

PubMed

Xu, Jianling; Cai, Qiongyao; Wang, Hanxi; Liu, Xuejun; Lv, Jing; Yao, Difu; Lu, Yue; Li, Wei; Liu, Yuanyuan

2017-05-01

In this study, the microwave digestion method was used to determine total cadmium (Cd) and lead (Pb) concentrations, the BCR method was used to determine different states of Cd and Pb, and atomic absorption spectroscopy (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to determine Cd and Pb concentrations in simulated soil and barnyard grass before and after planting barnyard grass to provide a theoretical basis for the remediation of Cd- and Pb-contaminated soil. The results showed that the bioconcentration factor changes with different Cd concentrations are relatively complex and that the removal rate increases regularly. The 100 mg kg -1 Cd treatment had the highest removal rate, which reached 36.66%. For Pb, the bioconcentration factor decreased and tended to reach equilibrium as the Pb concentration increased. The highest removal rate was 41.72% and occurred in the 500 mg kg -1 Pb treatment; however, this removal rate was generally lower than that of Cd. In addition, the reduction state had the highest change rate, followed by the residual, acid soluble and oxidation states. For Pb, the residual state has the highest change rate, followed by the acid soluble state, reduction state and oxidation state. In addition, a significant correlation was observed between the soil Pb and Cd concentrations and the concentrations of Pb and Cd that accumulated in the belowground biomass of the barnyard grass, but no significant correlation was observed between the soil Pb and Cd concentrations and the amounts of Pb and Cd that accumulated in the aboveground biomass of the barnyard grass. The highest transfer factor of Cd was 0.49, which occurred in the 5 mg kg -1 Cd treatment. The higher transfer factor of Pb was 0.48 in the 100 mg kg -1 Pb treatment. All of these factors indicate that the belowground biomass of barnyard grass plays a more important role in the remediation of Cd- and Pb-contaminated soils than the aboveground biomass of barnyard grass. Remediation should occur through phytostabilization. Thus, with its strong adaptability and lush growth, barnyard grass can be applied as a pioneer species for the phytoremediation of Cd- and Pb-contaminated soils.

Differences in the response of soil dehydrogenase activity to Cd contamination are determined by the different substrates used for its determination.

PubMed

Tan, Xiangping; Liu, Yanju; Yan, Kaihong; Wang, Ziquan; Lu, Guannan; He, Yike; He, Wenxiang

2017-02-01

Dehydrogenase activity (DHA) is an important indicator of heavy metal toxicity in contaminated soils. Different instances of DHA were determined using various substrates and which could affect the description of heavy metal toxicity. Currently, too few investigations have been done on selecting appropriate substrates. This study employed indoor simulation to determine soil DHA and its response to external cadmium (Cd) using two substrates (TTC and INT). Hormesis for DHA obtained using the TTC method (DHA-TTC) in low Cd concentration was observed which was quickly inhibited in high Cd concentration. While DHA obtained using the INT method (DHA-INT) decreased slowly when Cd concentration increased. The DHA-TTC and DHA-INT in soils at Cd concentration of 500 mg kg -1 decreased 86% and 53%, respectively, compared to the control. The dose-response relationship of Cd to DHA can be well simulated using the logistic model (p < 0.01), which indicated DHA could be used to indicate soil Cd toxicity. Multiple stepwise regression analysis revealed that total organic matter (TOC) is the major factor influencing the toxicity of Cd to DHA-TTC, while TOC, pH and cation exchange capacity (CEC) are major factors influencing the toxicity of Cd to DHA-INT. The different responses of soil DHA-TTC and DHA-INT to Cd are due to the differences in electron transport chain characteristics between TTC and INT, as well as the influence of soil properties. Although both DHA-TTC and DHA-INT can monitor soil Cd contamination, DHA-INT is recommended as a superior bio-indicator to indicate and assess contamination of Cd in soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Erosion of the Alberta badlands produces highly variable and elevated heavy metal concentrations in the Red Deer River, Alberta.

PubMed

Kerr, Jason G; Cooke, Colin A

2017-10-15

Erosion is important in the transport of heavy metals from terrestrial to fluvial environments. In this study, we investigated riverine heavy metal (Cd, Cu, Hg and Pb) dynamics in the Red Deer River (RDR) watershed at sites upstream (n=2) and downstream (n=7) of the Alberta badlands, an area of naturally high erosion. At sites draining the badlands, total water column Cd, Cu, Hg and Pb concentrations frequently exceeded guidelines for the protection of freshwater biota. Furthermore, peak concentrations of total Cd (9.8μgL -1 ), Cu (212μgL -1 ), Hg (649ngL -1 ) and Pb (361μgL -1 ) were higher than, or comparable to, values reported for rivers and streams heavily impacted by anthropogenic activities. Total suspended solids (TSS) explained a large proportion (r 2 =0.34-0.83) of the variation in total metal concentrations in the RDR and tributaries and metal fluxes were dominated by the particulate fraction (60-98%). Suspended sediment concentrations (C sed ) and metal to aluminum ratios were generally not indicative of substantial sediment enrichment. Rather, the highly variable and elevated metal concentrations in the RDR watershed were a function of the high and variable suspended sediment fluxes which characterize the river system. While the impact of this on aquatic biota requires further investigation, we suggest erosion in the Alberta badlands may be contributing to Hg-based fish consumption advisories in the RDR. Importantly, this highlights a broader need for information on contaminant dynamics in watersheds subject to elevated rates of erosion. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring

USGS Publications Warehouse

Schmitt, C.J.; Brumbaugh, W.G.; May, T.W.

2009-01-01

Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in "fillet" and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb-Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb-Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log-log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73-83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained <12% of the total variation. Fillet Pb and calcium concentrations were correlated (r = 0.83), but only in the 12 fish from the most contaminated site; concentrations were not significantly correlated across all sites. Conversely, fillet Cd and calcium were correlated across the range of sites (r = 0.78), and the inclusion of calcium in the fillet-to-blood relation explained an additional 12% of the total variation in fillet Cd. Collectively, the results indicate that blood sampling could provide reasonably accurate and precise estimates of fillet Pb, Co, and Cd concentrations that would be suitable for identifying contaminated sites and for monitoring, but some fillet sampling might be necessary at contaminated sites for establishing consumption advisories. ?? 2009 US Government.

Metal uptake by phytoplankton during a bloom in South San Francisco Bay: Implications for metal cycling in estuaries

USGS Publications Warehouse

Luoma, S.N.; VanGeen, A.; Lee, B.-G.; Cloern, J.E.

1998-01-01

The 1994 spring phytoplankton bloom in South San Francisco Bay caused substantial reductions in concentrations of dissolved Cd, Ni, and Zn, but not Cu. We estimate that the equivalent of ~60% of the total annual input of Cd, Ni, and Zn from local waste-water treatment plants is cycled through the phytoplankton in South Bay. The results suggest that processes that affect phytoplankton bloom frequency or intensity in estuaries (e.g. nutrient enrichment) may also affect metal trapping. The bloom was characterized by hydrographic surveys conducted at weekly intervals for 9 weeks. Metal samples were collected from the water column on three occasions, timed to bracket the period when the bloom was predicted. Factors that might confound observations of biological influences, such as freshwater inputs, were relatively constant during the study. Before the bloom, concentrations of dissolved Cd were 0.81 ?? 0.02 nmol kg-1, Zn concentrations were 19.8 ?? 1.5 nmol kg-1, Ni were 42 ?? 1.4 nmol kg-1, and Cu were 37 ?? 1.4 nmol kg-1. The values are elevated relative to riverine and coastal end-members, reflecting inputs from wastewater and(or) sediments. At the height of the bloom, dissolved Zn, Cd, and Ni were reduced to 19, 50, and 75% of their prebloom concentrations, respectively. Dissolved Cu concentrations increased 20%. The mass of Cd taken up by phytoplankton was similar to the mass of Cd removed from solution if particle settling was considered, and Cd concentrations estimated in phytoplankton were higher than concentrations in suspended particulate material (SPM). Particulate concentrations of Zn and Ni during the bloom appeared to be dominated by the influence of changes in resuspension of Zn- and Ni-rich sediments.

[Accumulation Characteristics and Evaluation of Heavy Metals in Soil-Crop System Affected by Wastewater Irrigation Around a Chemical Factory in Shenmu County].

PubMed

Qi, Yan-bing; Chu, Wan-lin; Pu, Jie; Liu, Meng-yun; Chang, Qing-rui

2015-04-01

Soil heavy metals Cu, Pb, Zn, and Cd, are regarded as "chemical time bombs" because of their propensity for accumulation in the soil and uptake by crops. This ultimately causes human toxicity in both the short and long-term, making farmland ecosystems dangerous to health. In this paper, accumulation and spatial variability of Cu, Zn, Pb and Cd in soil-crop system affected by wastewater irrigation around a chemical factor in northern Shaanxi province were analyzed. Results showed that wastewater irrigation around the chemical factory induced significant accumulation in soils compared with control areas. The average concentrations of available Cu and total Cu were 4.32 mg x kg(-1) and 38.4 mg x kg(-1), which were twice and 1.35 times higher than those of the control area, respectively. Soil Zn and Pb were slightly accumulated. Whereas soil Cd was significantly accumulated and was higher than the critical level of soil environmental quality (II), the available and total Cd concentrations were 0.248 mg x kg(-1) and 1.21 mg x kg(-1), which were 10 and 6.1 times higher than those of the control areas. No significant correlations were found between available and total heavy metals except between available Cd and total Cd. All the heavy metals were mainly accumulated in the top layer (0-10 cm). Spatially, soils and plants high in heavy metal concentration were distributed within the radius of about 100 m from the waste water outlet for Cu, Zn and Cd and about 200 m for Pb, and decreased exponentially with the distance from the factory. Affected by wastewater irrigation, contents of Cu, Pb and Cd in maize were 4.74, 0.129 and 0.036 mg x kg(-1) which were slightly higher than those in the control area. The content of Zn was similar to that in the control area. Affected by the vehicle exhaust, the over standard rate of Pb was 5.7% in maize. All the heavy metals did not show significant correlation between soil and crop, except Cd. The square correlation coefficients were 0.83 and 0.75 between soil available and total Cd with maize. Therefore, the chemical factory contributed to the accumulation of heavy metals in the soil around it, but the contribution to the crop was limited, and thus temporarily caused no threat to human health. The reason for the lower accumulation was the high soil pH and low soil organic matter content. But more attentions should be paid to the higher accumulation of Pb in the maize caused by the vehicle and dust.

Long-term variations of the riverine input of potentially toxic dissolved elements and the impacts on their distribution in Jiaozhou Bay, China.

PubMed

Wang, Changyou; Guo, Jinqiang; Liang, Shengkang; Wang, Yunfei; Yang, Yanqun; Wang, Xiulin

2018-03-01

The concentrations of the potentially toxic dissolved elements (PTEs) As, Hg, Cr, Pb, Cd, and Cu in the main rivers into Jiaozhou Bay (JZB) during 1981-2006 were measured, and the impact of the fluvial PTE fluxes on their distributions in the bay was investigated. The overall average concentration in the rivers into JZB ranged from 8.8 to 39.6 μg L -1 for As, 10.1 to 632.6 ng L -1 for Hg, 4.1 to 3003.6 μg L -1 for Cr, 8.5 to 141.9 μg L -1 for Pb, 1.1 to 34.2 μg L -1 for Cd, and 13.2 to 1042.8 μg L -1 for Cu. The interannual average concentration variations of the PTEs in these rivers were enormous, with maximum differences of 41-21,680 times, while their relative seasonal changes were far smaller with maximum differences of 3-12 times. The total annual fluvial fluxes for As, Hg, and Cr into JZB exhibited the inverse "U" pattern, while those for Pb and Cd showed the "N" pattern. As a whole, the total annual Cu flux presented a growing tendency from 1998 to 2006. In general, the changing trends of the PTE concentrations in JZB were similar to those of their annual fluxes from the rivers, indicating a great impact of their fluvial fluxes on their distributions in JZB. The annual concentration of Cd in the bay almost remained constant and differed from the fluvial flux of Cd. The diversified pattern of the environmental Kuznets curve (EKC) represented China's approach to industrialization as "improving while developing."

A scheme to scientifically and accurately assess cadmium pollution of river sediments, through consideration of bioavailability when assessing ecological risk.

PubMed

Song, Zhixin; Tang, Wenzhong; Shan, Baoqing

2017-10-01

Evaluating heavy metal pollution status and ecological risk in river sediments is a complex task, requiring consideration of contaminant pollution levels, as well as effects of biological processes within the river system. There are currently no simple or low-cost approaches to heavy metal assessment in river sediments. Here, we introduce a system of assessment for pollution status of heavy metals in river sediments, using measurements of Cd in the Shaocun River sediments as a case study. This system can be used to identify high-risk zones of the river that should be given more attention. First, we evaluated the pollution status of Cd in the river sediments based on their total Cd content, and calculated a risk assessment, using local geochemical background values at various sites along the river. Using both acetic acid and ethylenediaminetetraacetic acid to extracted the fractions of Cd in sediments, and used DGT to evaluate the bioavailability of Cd. Thus, DGT provided a measure of potentially bioavailable concentrations of Cd concentrations in the sediments. Last, we measured Cd contents in plant tissue collected at the same site to compare with our other measures. A Pearson's correlation analysis showed that Cd-Plant correlated significantly with Cd-HAc, (r = 0.788, P < 0.01), Cd-EDTA (r = 0.925, P < 0.01), Cd-DGT (r = 0.976, P < 0.01), and Cd-Total (r = 0.635, P < 0.05). We demonstrate that this system of assessment is a useful means of assessing heavy metal pollution status and ecological risk in river sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Cadmium Stress on Non-enzymatic Antioxidant and Nitric Oxide Levels in Two Varieties of Maize (Zea mays).

PubMed

Akinyemi, Ayodele Jacob; Faboya, Oluwabamise Lekan; Olayide, Israel; Faboya, Opeyemi Ayodeji; Ijabadeniyi, Tosin

2017-06-01

Cadmium (Cd) is one of the most toxic heavy metals that inhibit physiological processes of plants. Hence, the present study sought to investigate the effect of cadmium-contaminated seeds from two varieties of maize (Zea mays) on non-enzymatic antioxidant and nitric oxide levels. Seeds of yellow and white maize were exposed to different concentrations of Cd (0, 1, 3 and 5 ppm) for two weeks. The results from this study revealed that both varieties of maize bio-accumulate Cd in leaves in a dose-dependent manner. In addition, Cd exposure caused a significant (p < 0.05) decrease in total phenolic, GSH and nitric oxide (NO) levels at the highest concentration tested when compared with control. Therefore, the observed decrease in NO and endogenous antioxidant status by Cd treatment in maize plants could suggest some possible mechanism of action for Cd-induced oxidative stress and counteracting effect of the plants against Cd toxicity.

Trace elements and heavy metals in the Grand Bay National Estuarine Reserve in the northern Gulf of Mexico

PubMed Central

McComb, Jacqueline Q.; Han, Fengxiang X.; Rogers, Christian; Thomas, Catherine; Arslan, Zikri; Ardeshir, Adeli; Tchounwou, Paul B.

2015-01-01

The objectives of this study are to investigate distribution of trace elements and heavy metals in the salt marsh and wetland soil and biogeochemical processes in the Grand Bay National Estuarine Research Reserve of the northern Gulf of Mexico. The results show that Hg, Cd and to some extent, As and Pb have been significantly accumulated in soils. The strongest correlations were found between concentrations of Ni and total organic matter contents. The correlations decreased in the order: Ni > Cr > Sr > Co > Zn, Cd > Cu > Cs. Strong correlations were also observed between total P and concentrations of Ni, Co, Cr, Sr, Zn, Cu, and Cd. This may be related to the P spilling accident in 2005 in the Bangs Lake site. Lead isotopic ratios in soils matched well those of North American coals, indicating the contribution of Pb through atmospheric fallout from coal power plants. PMID:26238403

Cd2+ Toxicity to a Green Alga Chlamydomonas reinhardtii as Influenced by Its Adsorption on TiO2 Engineered Nanoparticles

PubMed Central

Yang, Wei-Wan; Miao, Ai-Jun; Yang, Liu-Yan

2012-01-01

In the present study, Cd2+ adsorption on polyacrylate-coated TiO2 engineered nanoparticles (TiO2-ENs) and its effect on the bioavailability as well as toxicity of Cd2+ to a green alga Chlamydomonas reinhardtii were investigated. TiO2-ENs could be well dispersed in the experimental medium and their pHpzc is approximately 2. There was a quick adsorption of Cd2+ on TiO2-ENs and a steady state was reached within 30 min. A pseudo-first order kinetics was found for the time-related changes in the amount of Cd2+ complexed with TiO2-ENs. At equilibrium, Cd2+ adsorption followed the Langmuir isotherm with the maximum binding capacity 31.9, 177.1, and 242.2 mg/g when the TiO2-EN concentration was 1, 10, and 100 mg/l, respectively. On the other hand, Cd2+ toxicity was alleviated in the presence of TiO2-ENs. Algal growth was less suppressed in treatments with comparable total Cd2+ concentration but more TiO2-ENs. However, such toxicity difference disappeared and all the data points could be fitted to a single Logistic dose-response curve when cell growth inhibition was plotted against the free Cd2+ concentration. No detectable amount of TiO2-ENs was found to be associated with the algal cells. Therefore, TiO2-ENs could reduce the free Cd2+ concentration in the toxicity media, which further lowered its bioavailability and toxicity to C. reinhardtii. PMID:22403644

The Influence of Tobacco Smoke on Protein and Metal Levels in the Serum of Women during Pregnancy

PubMed Central

Wrześniak, Marta; Kepinska, Marta; Królik, Małgorzata; Milnerowicz, Halina

2016-01-01

Background Tobacco smoking by pregnant women has a negative effect on fetal development and increases pregnancy risk by changing the oxidative balance and microelements level. Smoking affects the concentration, structure and function of proteins, potentially leading to various negative effects on pregnancy outcomes. Methodology/Principal Findings The influence of tobacco smoke on key protein fractions in smoking and non-smoking healthy pregnant women was determined by capillary electrophoresis (CE). Concentrations of the proteins α1-antitrypsin, α1-acid glycoprotein, α2-macroglobulin and transferrin were determined by ELISA tests. Total protein concentration was measured by the Biuret method. Smoking status was established by cotinine levels. Cadmium (Cd) and Zinc (Zn) concentrations were determined by flame atomic absorption spectrometry and the Zn/Cd ratio was calculated based on these numbers. Smoking women had a 3.7 times higher level of Cd than non-smoking women. Zn levels decreased during pregnancy for all women. The Zn/Cd ratio was three times lower in smoking women. The differences between the changes in the protein profile for smoking and non-smoking women were noted. Regarding proteins, α1-antitrypsin and α2-macroglobulin levels were lower in the non-smoking group than in the smoking group and correlated with Cd levels (r = -0.968, p = 0.032 for non-smokers; r = −0.835, p = 0.019 for smokers). Zn/Cd ratios correlated negatively with α1-, α2- and β-globulins. Conclusions/Significance Exposure to tobacco smoke increases the concentration of Cd in the blood of pregnant women and may lead to an elevated risk of pregnancy disorders. During pregnancy alter concentrations of some proteins. The correlation of Cd with proteins suggests that it is one of the causes of protein aberrations. PMID:27548057

Temporal Variation and Ecological Risk Assessment of Metals in Soil Nearby a Pb⁻Zn Mine in Southern China.

PubMed

Cao, Congcong; Wang, Li; Li, Hairong; Wei, Binggan; Yang, Linsheng

2018-05-09

Metal contamination in soil from tailings induces risks for the ecosystem and for humans. In this study, the concentrations and ecological risks of Cd, Cu, Pb, and Zn in soil contaminated by a tailing from Yangshuo (YS) lead and zinc (Pb⁻Zn) mine, which collapsed for more than 40 years, were determined in 2015. The mean concentrations of Zn, Pb, Cu, and Cd were 1301.79, 768.41, 82.60, and 4.82 mg/kg, respectively, which, with years of remediation activities, decreased by 66.9%, 61.7%, 65.4%, and 65.3% since 1986, but still exceed the national standards. From 1986 to 2015, soil pH increased significantly, with available concentrations of Zn, Pb, Cu and Cd decreasing by 13%, 81%, 77%, and 67%, respectively, and potential ecological risk indexes ( E r ) of the determined metals decreasing by more than 60%. Horizontally, total contents and percentages of available concentrations of Zn, Pb, Cu, and Cd decreased with the distance from the tailing heap in SD village, while pH values showed the reverse pattern. Vertically, Zn and Cd, Pb, and Cu showed similar vertical distribution patterns in the soil profiles. There was a slight downward migration for the determined metals in soil of M and H area and the mobility was in the order of Cd > Zn > Pb > Cu. It can be concluded that although concentrations and ecological risks of Cd, Cu, Pb, and Zn in soil decreased significantly, SD village is still a high risk area, and the priority pollutant is Cd.

Temporal Variation and Ecological Risk Assessment of Metals in Soil Nearby a Pb–Zn Mine in Southern China

PubMed Central

Cao, Congcong; Wang, Li; Li, Hairong; Wei, Binggan

2018-01-01

Metal contamination in soil from tailings induces risks for the ecosystem and for humans. In this study, the concentrations and ecological risks of Cd, Cu, Pb, and Zn in soil contaminated by a tailing from Yangshuo (YS) lead and zinc (Pb–Zn) mine, which collapsed for more than 40 years, were determined in 2015. The mean concentrations of Zn, Pb, Cu, and Cd were 1301.79, 768.41, 82.60, and 4.82 mg/kg, respectively, which, with years of remediation activities, decreased by 66.9%, 61.7%, 65.4%, and 65.3% since 1986, but still exceed the national standards. From 1986 to 2015, soil pH increased significantly, with available concentrations of Zn, Pb, Cu and Cd decreasing by 13%, 81%, 77%, and 67%, respectively, and potential ecological risk indexes (Er) of the determined metals decreasing by more than 60%. Horizontally, total contents and percentages of available concentrations of Zn, Pb, Cu, and Cd decreased with the distance from the tailing heap in SD village, while pH values showed the reverse pattern. Vertically, Zn and Cd, Pb, and Cu showed similar vertical distribution patterns in the soil profiles. There was a slight downward migration for the determined metals in soil of M and H area and the mobility was in the order of Cd > Zn > Pb > Cu. It can be concluded that although concentrations and ecological risks of Cd, Cu, Pb, and Zn in soil decreased significantly, SD village is still a high risk area, and the priority pollutant is Cd. PMID:29747376

Evidence for metabolic imbalance of vitamin A2 in wild fish chronically exposed to metals.

PubMed

Defo, Michel A; Pierron, Fabien; Spear, Philip A; Bernatchez, Louis; Campbell, Peter G C; Couture, Patrice

2012-11-01

In a recent study on indigenous yellow perch chronically exposed to metals, we reported a negative correlation between liver metal concentration and liver transcription levels of genes encoding for enzymes involved in the metabolism of retinoids. We therefore speculated that metals, and especially the non-essential metal Cd, could alter the metabolism of retinoids in wild fish. Thus the present field study investigates the impact of in situ metal exposure on retinoid storage. A total of 55 yellow perch (Perca flavescens) were sampled in six lakes representing a metal contamination gradient (8≤N≤10 per lake). Our results show that yellow perch from Cd-contaminated lakes had significantly higher concentrations of liver dehydroretinol and dehydroretinyl esters than did fish from reference lakes. However, the increase in retinyl ester stores with increasing Cd concentrations was quantitatively much more important than the increase in free dehydroretinol. As a result, a significant decrease in the percentage of hepatic free dehydroretinol with increasing renal Cd concentrations was observed. These results suggest that the enzymes and the binding proteins involved in vitamin A homeostasis are inhibited by the presence of Cd. Alternatively, the increase in tissue vitamin A (antioxidant) levels could serve to better counteract the oxidative stress engendered by Cd exposure. Overall our findings illustrate that vitamin A(2) homeostasis can be altered as a consequence of chronic exposure to low Cd concentrations. Thus, in the context of environmental risk assessment, the percentage of liver free dehydroretinol can be considered as a biomarker of for in situ Cd exposure. Copyright © 2012 Elsevier Inc. All rights reserved.

Assessing metal bioavailability from cytosolic metal concentrations in natural populations of aquatic insects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cain, D.J.; Luoma, S.N.; Hornberger, M.I.

1995-12-31

Metals occur in a variety of forms in aquatic insects. Some of these forms may be irrelevant to effects of metals on the animal, and might actually obscure links between tissue residues, metal bioavailability and toxicity (e.g. metals sorbed to external body parts, or associated with unpurged gut contents). Cytosolic metal may be a sensitive indicator of metal bioavailability and toxicity. The authors determined cytosolic metal concentrations in natural populations of the caddisfly (Trichoptera) Hydropsyche occidentalis. Cytosolic metal concentrations were compared to whole-body and sediment metal concentrations. Samples were collected along a contamination gradient over a 380 km reach ofmore » the Clark Fork River, Montana, in August of 1992 and 1993. Concentrations of cytosolic Cd, Cu, and Pb correlated with concentrations of these metals in the whole body within years. Cytosolic metals also correlated with levels of sediment contamination except at the most contaminated sites where metal concentrations in the cytosol were lower relative to sediments. The availability of Pb appeared to be low since the cytosolic Pb fraction represented less than 6% of the total Pb body burden. The cytosol contained appreciably higher proportions of the total Cd and Cu body burden than Pb. The cytosolic fraction of Cd and Cu also increased significantly between 1992 and 1993. This change reflected an increase in Cd and Cu exposure in 1993, apparently due to the mobilization of metals during higher river flows that year. The shift in cytosolic metal fractions demonstrates the dynamic nature of metal partitioning in animals in nature. These shifts can be influenced by hydrologic and geochemical conditions, as well as biological processes.« less

Toxicity of cadmium to goldfish, Carassius auratus, in hard, and soft water

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCarty, L.S.; Henry, J.A.C.; Houston, A.H.

1978-01-01

Variations in cadmium form and concentration and in selected water quality parameters (pH, dissolved oxygen, total hardness, total alkalinity, conductivity) were monitored during static bioassays conducted with relatively soft (approximately 20 mg/L as CaCO/sub 3/) and hard (approximately 140 mg/L as CaCO/sub 3/) waters. Cadmium concentrations were reasonably stable in soft water, and with the exception of total hardness, water quality was not greatly altered during assay. Cumulative mortality curves were of a simple sigmoidal type and readily analyzed by conventional procedures. LC50 values of 2.76, 2.13, and 1.78 mg Cd/L were estimated on the basis of 48-, 96-, andmore » 240-h periods of observation. During hard-water trials there were transient increases in the amount of particulate cadmium present and sharp decreases in total cadmium levels. Several parameters (pH, total alkalinity, conductivity) exhibited transient and/or sustained variations of a cadmium concentration-dependent type. Mortality curves were typically biphasic. The extent of first-phase mortality was significantly correlated with the magnitude of the initial pH decline and the amount of cadmium present in centrifugable form. Conventional procedures did not result in rectification of 240-h cumulative mortality curves, and the 240-h LC50 value (40.2 mg Cd/L) is considered to be inherently less precise than those obtained on the basis of 48- and 96-h periods of observation (46.9, 46.8 mg Cd/L).« less

Heavy metal (Cu, Zn, Cd and Pb) partitioning and bioaccessibility in uncontaminated and long-term contaminated soils.

PubMed

Lamb, Dane T; Ming, Hui; Megharaj, Mallavarapu; Naidu, Ravi

2009-11-15

We investigated the pore-water content and speciation of copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in a range of uncontaminated and long-term contaminated soils in order to establish their potential bioaccessibility to soil biota, plants and humans. Among the samples, soil pH (0.01 M CaCl(2)) ranged from 4.9 to 8.2. The total metal content of the uncontaminated soils ranged from 3.8 to 93.8 mg Cu kg(-1), 10.3 to 95 mg kg(-1) Zn, 0.1 to 1.8 mg Cd kg(-1) and 5.2 to 183 mg kg(-1) Pb, while metal content in the contaminated soils ranged from 104 to 6841 mg Cu kg(-1), 312 to 39,000 mg kg(-1) Zn, 6 to 302 mg Cd kg(-1) and 609 to 12,000 mg kg(-1) Pb. Our analysis of pore-water found the Cu concentrations to be much higher in contaminated soils than in uncontaminated soils, with the distribution coefficients (K(d)) correlating significantly with the log of dissolved organic carbon concentrations. Despite the high total metal content of the contaminated soil, Zn, Cd and Pb were not generally found at elevated levels in the pore-water with the exception of a single contaminated soil. A long period of ageing and soil weathering may have led to a substantial reduction in heavy metal concentrations in the pore-water of contaminated soils. On the other hand, Pb bioaccessibility was found to be comparatively high in Pb contaminated soils, where it tended to exceed the total Pb values by more than 80%. We conclude that, despite the extensive ageing of some contaminated soils, the bioaccessibility of Pb remains relatively high.

Only Follow-Up of Memory B Cells Helps Monitor Rituximab Administration to Patients with Neuromyelitis Optica Spectrum Disorders.

PubMed

Lebrun, Christine; Cohen, Mikael; Rosenthal-Allieri, Maria Alessandra; Bresch, Saskia; Benzaken, Sylvia; Marignier, Romain; Seitz-Polski, Barbara; Ticchioni, Michel

2018-06-07

Neuromyelitis optica spectrum disorders (NMOSD) are identified as a spectrum of inflammatory demyelinating disorders involving the brain, spinal cord and optic nerves. These disorders require early diagnosis and highly active immunosuppressive treatment. Rituximab (RTX) has demonstrated efficacy in limiting relapse in NMOSD when using several administration schedules. We questioned if the CD19+ CD27+ memory B cell count was a more reliable marker to monitor RTX administration than the RTX plasma level and CD19+ B cell count. We analyzed 125 blood samples from 17 NMOSD patients treated with RTX and also measured the level of anti-aquaporine-4 antibodies (anti-AQP-4 Abs), human anti-chimeric antibodies to the murine fragment of RTX (HACA-RTX Abs), and the RTX concentration. The mean follow-up time of the cohort was 7.4 (2-16) years. All patients improved with a mean EDSS going from 4 (1-8.5) to 2.7 (1-5.5). The mean interval between RTX infusions was 9.6 months with identification of prolonged responders. Total CD19+ B cell detection with the routine technique did not correlate to re-emergence of CD19+ CD27+ memory B cells. The RTX residual concentration did not correlate with the CD19+ CD27+ memory B cell count or with anti-RTX antibody production. In contrast to total CD19+ cell, detected with the routine technique, CD19+ CD27+ memory B cells are a reliable marker for biological relapse and allow a decrease in the frequency of infusions.

Spatial characteristics of cadmium in topsoils in a typical e-waste recycling area in southeast China and its potential threat to shallow groundwater.

PubMed

Wu, Chunfa; Luo, Yongming; Deng, Shaopo; Teng, Ying; Song, Jing

2014-02-15

Informal electrical and electronic waste (e-waste) recycling often creates secondary sources of cadmium (Cd) pollution. To characterize the total Cd concentration (Cdtotal) in topsoil and evaluate the threat of Cd in topsoils to shallow groundwater, 187 topsoil samples and 12 shallow groundwater samples were collected in a typical e-waste recycling area in southeast China. Soil organic matter content, soil pH and Cdtotal in topsoil, pH and dissolved Cd concentration in shallow groundwater were measured. Cdtotal in the topsoils showed an inverse distribution trend with soil pH in that high Cd concentrations (and low pH values) were found in the surrounding area of the metal recycling industrial park where there were many family-operated e-waste recycling facilities before the industrial park was established and with low concentrations (and high pH values) in other areas, and they had similar spatial correlation structures. Cd accumulation and acidification were synchronous in topsoils, and soil pH was significantly correlated with Cdtotal in topsoils with low to moderate negative correlation coefficient (r=-0.24), indicating that both of them maybe correlated with informal recycling. The shallow groundwater in the surrounding area of the metal recycling industrial park was seriously contaminated by Cd, and topsoil Cd accumulation and acidification in the surrounding area of e-waste recycling sites significantly increase the risk of shallow groundwater contaminated by Cd. Action is urgently required to control Cd accumulation and acidification by improving the recycling operations of e-wastes in order to reduce the risk of Cd leaching from topsoils and shallow groundwater contamination. Copyright © 2013. Published by Elsevier B.V.

Heavy metal leaching from mine tailings as affected by plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, D.; Schwab, A.P.; Banks, M.K.

A column experiment was conducted to determine the impact of soil cover and plants on heavy metal leaching from mine tailings and heavy metal contaminated soil. Columns made of PVC were constructed with 30 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm of clean topsoil. Two grasses, tall fescue (Festuca arundinacea Schreb.) and big bluestem (Andropogon gerardii), were grown in the columns. The columns were leached at a slow rate for 1 yr with a 0.001 Mmore » CaCl{sub 2} solution under unsaturated conditions. The presence of both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate. Lead concentrations in leachates were not affected by the presence of plants. Although plants generally reduced the total amount of water leached, total mass of Zn and Cd leached generally was not impacted by plants. Total mass of Pb leached was positively correlated with total leachate collected from each column. Covering the mine tailings with 60 cm of topsoil increased the mass of Zn and Cd leached relative to no topsoil. When the subsoil was absent, Zn and Cd leaching increased by as much as 20-fold, verifying the ability of soil to act as a sink for metals. Mine tailing remediation by establishing vegetation can reduce Pb movement but may enhance short-term Cd and Zn leaching. However, the changes were relatively small and do not outweigh the benefits of using vegetation in mine tailings reclamation.« less

Effect of Inoculation with Glomus versiforme on Cadmium Accumulation, Antioxidant Activities and Phytochelatins of Solanum photeinocarpum

PubMed Central

Tan, Shi-Yun; Jiang, Qiu-Yun; Zhuo, Feng; Liu, Hui; Wang, Yu-Tao; Li, Shao-Shan; Ye, Zhi-Hong; Jing, Yuan-Xiao

2015-01-01

The plant growth, phosphate acquisition, Cd translocation, phytochelatins (PCs) production and antioxidant parameters [superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione (GSH), ascorbate (ASA) and malonaldehyde (MDA)] were investigated in Cd-hyperaccumulator Solanum photeinocarpum inoculated with Glomus versiforme BGC GD01C (Gv) in Cd-added soils (0, 5, 10, 20, 40 mg Cd kg-1 soil). Mycorrhizal colonization rates were generally high (from 77% to 94%), and hardly affected by Cd. Gv colonization significantly enhanced P acquisition, growth and total Cd uptakes in both shoots and roots of S. photeinocarpum at all Cd levels. Meanwhile, Gv symbiosis significantly increased Cd concentration in the roots, and decreased Cd concentration in the shoots at all Cd levels, which indicates that Gv could promote phytostabilization by enhancing Cd accumulation in the roots to inhibit its translocation to shoots and the “dilution effects” linked to an increase in plant dry matter yield and a reduced Cd partitioning to shoots. Moreover, the improvement of CAT, POD and APX activities in the leaves of mycorrhizal plants infers that Gv symbiosis helped S. photeinocarpum to relieve oxidative damage to biomolecules in Cd-contaminated soil. The evident decline of MDA content in the leaves of mycorrhizal plants indicates that Gv symbiosis evidently improved antioxidant activities, and the enhancement of PCs production in the leaves of mycorrhizal plants suggests that Gv-inoculated plant may be more efficient to relieve Cd phytotoxicity. Therefore, the possible mechanisms of Cd phytotoxicity alleviation by Gv can be concluded as the decline of Cd concentration in the shoots and the improvement of P acquisition, PCs production and activities of CAT, POD, APX in mycorrhizal plants. PMID:26176959

Application of poly (ethyleneimine) solution as a binding agent in DGT technique for measurement of heavy metals in water.

PubMed

Sui, Dian-Peng; Fan, Hong-Tao; Li, Jing; Li, You; Li, Qiong; Sun, Ting

2013-09-30

A 0.050 mol L(-1) solution of poly (ethyleneimine) (PEI), had been used as a novel binding agent of diffusive gradients in thin-films (DGT) technique (PEI-DGT) for measuring the concentrations of labile Cu(2+), Cd(2+) and Pb(2+) in waters. The binding capacities of the PEI-DGT for Cu(2+), Cd(2+) and Pb(2+) were 11.8, 10.2 and 10.6 μmol L(-1), respectively. The performance of PEI-DGT was independence of pH in the range of 4-8 and ionic strength in the range from 1×10(-4) to 0.1 mol L(-1) (as NaNO3). PEI-DGT could measure 104.7±5.2% of the total concentration of Cd(2+) (0.500 mg L(-1)), 95.2±4.3% of the total Cu(2+) (0.500 mg L(-1)) and 99.2±3.4% of the total Pb(2+) (0.500 mg L(-1)) in synthetic solution. Effects of the ligands on the measurement of labile metals were also investigated in synthetic solutions containing the various concentrations of EDTA and humic acid. In EDTA solution, the concentrations of labile metals measured by PEI-DGT showed good agreement with the theoretical concentrations of free metal ions. In humic acid solution, the concentrations of labile metals measured by PEI-DGT decreased with the increase of the concentrations of humic acid. Several DGT devices with various binding agents, including PEI, sodium polyacrylate and poly(4-styrenesulfonate) solution, were used for the measurement of labile fractions of Cu(2+), Cd(2+) and Pb(2+) in the spiked waters and in mine wastewaters. The results showed that the concentrations of labile metal measured by DGT devices with different binding agents could be significantly different, indicating that the labile fractions of metals were dependent on the binding strength of the binding agents with metals. By choosing binding agents, the useful information on the speciation and bioavailability of the analytes can be provided. Copyright © 2013 Elsevier B.V. All rights reserved.

Concentration of heavy metals in vegetables and potential health risk assessment in China.

PubMed

Zhong, Taiyang; Xue, Dawei; Zhao, Limin; Zhang, Xiuying

2018-02-01

Food safety is an important issue in the world. This study assessed the health risk for the Chinese public when consuming vegetables grown in China, based on 1335 data records from 220 published papers during 2007-2016. The results showed that the average of Pb, Cd, and Hg concentration in vegetables was 0.106, 0.041, and 0.008 mg/kg, which were lower than the maximum allowable concentrations, respectively. Leaf vegetables contained higher heavy metals than root vegetables and fruit vegetables. On a provincial scale, the highest Pb, Cd, and Hg concentrations in vegetables were determined by those in soil and atmosphere. The total health risk index showed that people in Guizhou, Yunnan, Guangxi, Hunan, Guangdong, Hubei provinces in southern China, and Liaoning Province in northeast China, faced a high risk of Pb, Cd, and Hg when consuming vegetables.

Release of cadmium in contaminated paddy soil amended with NPK fertilizer and lime under water management.

PubMed

Han, Xiao-Qing; Xiao, Xi-Yuan; Guo, Zhao-Hui; Xie, Ye-Hua; Zhu, Hui-Wen; Peng, Chi; Liang, Yu-Qin

2018-05-03

Agricultural soils contaminated with cadmium (Cd) pose a risk to receiving surface water via drainage or runoff. A 90-day laboratory incubation experiment was conducted to investigate the release characteristics and transformation of Cd from contaminated paddy soil amended with agrochemical (NPK fertilizer) and lime (L) under water management regimes of continuous flooding (F) and drying-wetting cycles (DW). The result showed that the dissolved Cd concentrations in overlying water of the fertilizer treatment under flooding (NPK+F) and drying-wetting (NPK+DW) reached up to 81.0 μg/L and 276 μg/L, and were much higher than that from the corresponding controls without NPK fertilizer addition at the end of experiment. The Cd concentration showed significantly negative correlation with overlying water pH, but positive correlation with soil redox potential and concentrations of dissolved total nitrogen, sulfate and manganese in overlying water (P < 0.05), indicating that drying-wetting cycles and N fertilizer addition may enhance soil Cd release. The Cd concentrations in overlying water from all treatments except NPK+L+F treatment exceeded the Cd threshold limit of Chinese Environmental Quality Standards for Surface Water (10 μg/L Grade V) and poses potential risk to surface water quality. Meanwhile, the proportion of Cd in the acid-soluble fraction from all incubated soil except NPK+L+F treatment increased compared to before incubation. The results indicated that continuous flooding was a reasonable water management candidate coupled with lime addition for immobilizing soil Cd. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of composting on the Cd, Zn and Mn content and fractionation in feedstock mixtures with wood chips from a short-rotation coppice and bark.

PubMed

Vandecasteele, B; Willekens, K; Zwertvaegher, A; Degrande, L; Tack, F M G; Du Laing, G

2013-11-01

Micronutrient content and availability in composts may be affected by the addition of wood chips or tree bark as a bulking agent in the compost feedstock. In the first part of this study, micronutrient levels were assessed in bark and wood of poplar and willow clones in a short-rotation coppice. Large differences between species were observed in bark concentrations for Cd, Zn and Mn. In the second part of the study, we aimed to determine the effect of feedstock composition and composting on Cd, Zn and Mn concentrations and availability. By means of three composting experiments we examined the effect of (a) bark of different tree species, (b) the amount of bark, and (c) the use of bark versus wood chips. In general, compost characteristics such as pH, organic matter and nutrient content varied due to differences in feedstock mixture and composting process. During the composting process, the availability of Cd, Zn and Mn decreased, although the use of willow and poplar bark or wood chips resulted in elevated total Cd, Zn or Mn concentrations in the compost. Cd concentrations in some composts even exceeded legal criteria. Cd and Zn were mainly bound in the reducible fraction extracted with 0.5M NH2OH⋅HCl. A higher acid-extractable fraction for Mn than for Cd and Zn was found. Higher Cd concentrations in the compost due to the use of bark or wood chips did not result in higher risk of Cd leaching. The results of the pH-stat experiment with gradual acidification of composts illustrated that only a strong pH decline in the compost results in higher availability of Cd, Zn and Mn. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cadmium uptake by cocoa trees in agroforestry and monoculture systems under conventional and organic management.

PubMed

Gramlich, A; Tandy, S; Andres, C; Chincheros Paniagua, J; Armengot, L; Schneider, M; Schulin, R

2017-02-15

Cadmium (Cd) uptake by cocoa has recently attracted attention, after the European Union (EU) decided to establish values for tolerable Cd concentrations in cocoa products. Bean Cd concentrations from some cocoa provenances, especially from Latin America, were found to exceed these values. Cadmium uptake by cocoa is expected not only to depend on a variety of soil factors, but also on plant and management factors. In this study, we investigated the influence of different production systems on Cd uptake by cocoa in a long-term field trial in the Alto Beni Region of Bolivia, where cocoa trees are grown in monocultures and in agroforestry systems, both under organic and conventional management. Leaf, fruits and roots of two cultivars were sampled from each production system along with soil samples collected around these trees. Leaf, pod husk and bean samples were analysed for Cd, iron (Fe) and zinc (Zn), the roots for mycorrhizal abundance and the soil samples for 'total' and 'available' Cd, Fe and Zn as well as DGT-available Cd and Zn, pH, organic matter, texture, 'available' phosphorus (P) and potassium (K). Only a small part of the variance in bean and pod husk Cd was explained by management, soil and plant factors. Furthermore, the production systems and cultivars alone had no significant influence on leaf Cd. However, we found lower Cd leaf contents in agroforestry systems than in monocultures when analysed in combination with DGT-available soil Cd, cocoa cultivar and soil organic matter. Overall, this model explained 60% of the variance of the leaf Cd concentrations. We explain lower leaf Cd concentrations in agroforestry systems by competition for Cd uptake with other plants. The cultivar effect may be explained by cultivar specific uptake capacities or by a growth effect translating into different uptake rates, as the cultivars were of different size. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of cadmium on lipids of almond seedlings (Prunus dulcis).

PubMed

Elloumi, Nada; Zouari, Mohamed; Chaari, Leila; Jomni, Chiraz; Marzouk, Brahim; Ben Abdallah, Ferjani

2014-12-01

Cadmium uptake and distribution, as well as its effects on lipid composition was investigated in almond seedlings (Prunus dulcis) grown in culture solution supplied with two concentrations of Cd (50 and 150 μM). The accumulation of Cd increased with external metal concentrations, and was considerably higher in roots than in leaves. Fourteen days after Cd treatment, the membrane lipids were extracted and separated on silica-gel thin layer chromatography (TLC). Fatty acid methyl esters were analyzed by FID-GC on a capillary column. Our results showed that Cd stress decreased the quantities of all lipids classes (phospholipids, galactolipids and neutral lipids). Galactolipid, phospholipid and neutral lipid concentrations decreased more in roots than in leaves by Cd-treatment. In almost all lipid classes the proportion of palmitic acid (16:0), linoleic (18: 2) and that of linolenic (18: 3) acid decreased, suggesting that heavy metal treatment induced an alteration in the fatty acid synthesis processes. In conclusion, our results show that the changes found in total fatty acids, in the quantities of all lipids classes, and in the in the profiles of individual polar lipids suggest that membrane structure and function might be altered by Cd stress.

Ecological risk assessment of heavy metals in brown trout (Salmo trutta m. fario) from the military training area Boletice (Czech republic).

PubMed

Dvořák, Petr; Andreji, Jaroslav; Mráz, Jan; Dvořáková-Líšková, Zuzana; Klufová, Renata

2016-12-18

This study to assess the environmental pollution status in streams (Loutecky, Spicak, Olsina, Trebovicky, Polecnicky and Luzny) from the Boletice area. Were determined of some metal (Hg, Pb, Cd) concentrations in the muscle and correlations among selected metals as well as standard length and total weight in brown trouth - Salmo trutta morpha fario. The contents of the analyzed metals in muscles were Hg 0.19-0.72, Pb 0.01-0.6 and Cd 0.020-0.083 mg/kg wet weight basis and these concentrations did not exceed the limits admissible in the Czech Republic. The Czech republic permissible limit for Hg (0.5 mg/kg to omnivors, 1 mg/kg to predators), Pb (0.3 mg/kg) and Cd (0.05 mg/kg) defined in the Codex Alimentarius for safe human consumption exceeded in 6%, 3%, and 0% of analyzed samples for Hg, Pb and Cd respectively. On an average, the order of metal concentrations in the fish muscle was: Hg>Pb>Cd.

Vermicomposting of sugar industry waste (press mud) mixed with cow dung employing an epigeic earthworm Eisenia fetida.

PubMed

Sangwan, P; Kaushik, C P; Garg, V K

2010-01-01

In India, millions of tons of press mud (PM) are generated by sugar mills every year. This paper reports the potential of vermitechnology to convert sugar industry waste PM mixed with cow dung (CD) into vermicompost, employing an epigeic earthworm Eisenia fetida. A total of six different reactors were established having different ratios of PM and CD including one control (CD only). The growth and fecundity of E. fetida was monitored for 13 weeks. Maximum growth was recorded in 100% CD, but earthworms grew and reproduced favourably up to 1:1 PM and CD feed composition. However, greater percentages of PM in different reactors significantly affected the growth and fecundity of worms. Vermicomposting resulted in a decrease in carbon concentration and an increase in nitrogen, phosphorus and calcium concentrations of the vermicompost. Investigations indicated that vermicomposting could be an alternative technology for the management of PM into useful fertilizing material, if mixed at maximum 50% with CD.

Use of an intact core and stable-metal isotopes to examine leaching characteristics of a fluvial tailings deposit

USGS Publications Warehouse

Ranville, James F.; Smith, Kathleen S.; Lamothe, Paul J.; Jackson, Brian P.; Walton-Day, Katherine

2003-01-01

In this paper, we use Cd as an example of the utility of stable-metal isotopes in geochemical studies. In the case of Cd, after the core was partially saturated, the 111Cd spike was released as evidenced by a change in the Cd isotope ratios in the effluent. This release continued during the fully saturated leaching phase, however, the total Cd concentration did not increase. These results suggest that the 111Cd spike was retained inside the core during the unsaturated leaching phase, and only partially released as reducing conditions developed. Results from this core-leaching experiment indicate there is a large reservoir of water-soluble material within the fluvial tailings deposit, which yields elevated metal concentrations and high acidity, and which may degrade adjacent ground- and surface-water quality. Use of stable metal isotopes in this study facilitated the determination of different metal-retention processes, metal-release processes, and metal sources in the fluvial tailings deposit in response to changing geochemical conditions.

The effect of municipal sludge compost on the mobility and bioavailability of Cd in a sierozem-wheat system in an arid region northwest of China.

PubMed

Liu, Zheng; Yang, Yang; Bai, Ying; Huang, Yu; Nan, Zhongren; Zhao, Chuanyan; Ma, Jianmin; Wang, Houcheng

2016-10-01

The effect of sewage sludge on the mobility and the bioavailability of trace metals in plant-soil systems have aroused wide interested and been widely explored. Based on a wheat-cultivating experiment, the effect of municipal sludge compost (MSC) on the mobility and bioavailability of Cd in a soil-wheat system was studied. With the application of MSC, soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) in the soil increased significantly, while concentrations of trace metals (Cu, Zn, Ni, Pb, Cd) were below the China's minimum thresholds. The application of MSC could improve wheat growth. The application of MSC at the rate of 0.5 % had no significant effect on the chemical fraction distribution of Cd in soil. In two soil treatments, Cd mainly existed in the labile chemical fractions (exchangeable chemical fraction (EXCF) and carbonate chemical fraction (CABF)). However, the application of MSC could reduce accumulation of Cd by wheat. Cd contents in each part of the MSC-applied wheat were significantly less than that of non-MSC-applied wheat. In the tested soils, the extractable concentrations decreased in the order: EDTA > MgCl 2 ≈ NH 4 OAc > DTPA. There were no significant differences between soil treatments in the amounts of extractable Cd when the extraction was done under neutral conditions, although significant differences were observed when the extraction was done under alkaline conditions. In this study, the DTPA extraction procedure provided a good indication of Cd bioavailability. Our results suggest that, in the short term at least, amending soils with MSC may benefit crop dry matter production while not increasing the risk of human exposure to Cd through consumption of wheat grown on MSC-amended soils.

Cadmium hampers salt tolerance of Sesuvium portulacastrum.

PubMed

Wali, Mariem; Martos, Soledad; Pérez-Martín, Laura; Abdelly, Chedly; Ghnaya, Tahar; Poschenrieder, Charlotte; Gunsé, Benet

2017-06-01

It is well known that salinity reduces cadmium toxicity in halophytes. However, the possible interference of Cd with the mechanisms of salt tolerance is poorly explored. The aim of this study was to see whether Cd affects salt tolerance mechanisms in the halophyte Sesuvium portulacastrum. S. portulacastrum plants obtained from cuttings were grown in hydroponics for 3 weeks and then exposed to low (0.09 mM) or moderate (200 mM) NaCl concentrations, alone or in combination with 25 μM CdCl 2 . Microscopy observation revealed two strategies of salt tolerance: euhalophytism and secretion of salt by bladder cells. Cadmium exposure hardly influenced the total leaf Na + concentrations. However, Cd supply delayed the salt-induced upregulation of AHA1 (plasma membrane H + -ATPase 1) and SOS1 (plasma membrane Na + transporter "Salt Overly Sensitive 1"), genes that are essential for salt tolerance. Moreover, Cd induced the activation of BADH, coding for betaine aldehyde dehydrogenase, indicating enhanced osmotic stress due to Cd. Sodium-green fluorescence in protoplasts from plants grown with low or high NaCl, alone or in combination with Cd, revealed higher Na + concentrations in the cytoplasm of Cd-exposed plants. Taken together the results indicate interference of Cd with salt tolerance mechanisms in S. portulacastrum. This may have consequences for the efficient use of halophytes in phytoremediation of Cd-contaminated saline soils. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Impact of soil properties on critical concentrations of cadmium, lead, copper, zinc, and mercury in soil and soil solution in view of ecotoxicological effects.

PubMed

de Vries, Wim; Lofts, Steve; Tipping, Ed; Meili, Markus; Groenenberg, Jan E; Schütze, Gudrun

2007-01-01

Risk assessment for metals in terrestrial ecosystems, including assessments of critical loads, requires appropriate critical limits for metal concentrations in soil and soil solution. This chapter presents an overview of methodologies used to derive critical (i) reactive and total metal concentrations in soils and (ii) free metal ion and total metal concentrations in soil solution for Cd, Pb, Cu, Zn, and Hg, taking into account the effect of soil properties related to ecotoxicological effects. Most emphasis is given to the derivation of critical free and total metal concentrations in soil solution, using available NOEC soil data and transfer functions relating solid-phase and dissolved metal concentrations. This approach is based on the assumption that impacts on test organisms (plants, microorganisms, and soil invertebrates) are mainly related to the soil solution concentration (activity) and not to the soil solid-phase content. Critical Cd, Pb, Cu, Zn, and Hg concentrations in soil solution vary with pH and DOC level. The results obtained are generally comparable to those derived for surface waters based on impacts to aquatic organisms. Critical soil metal concentrations, related to the derived soil solution limits, can be described as a function of pH and organic matter and clay content, and varying about one order of magnitude between different soil types.

Regional accumulation characteristics of cadmium in vegetables: Influencing factors, transfer model and indication of soil threshold content.

PubMed

Yang, Yang; Chen, Weiping; Wang, Meie; Peng, Chi

2016-12-01

A regional investigation in the Youxian prefecture, southern China, was conducted to analyze the impact of environmental factors including soil properties and irrigation in conjunction with the use of fertilizers on the accumulation of Cd in vegetables. The Cd transfer potential from soil to vegetable was provided by the plant uptake factor (PUF), which varied by three orders of magnitude and was described by a Gaussian distribution model. The soil pH, content of soil organic matter (SOM), concentrations of Zn in the soil, pH of irrigation water and nitrogenous fertilizers contributed significantly to the PUF variations. A path model analysis, however, revealed the principal control of the PUF values resulted from the soil pH, soil Zn concentrations and SOM. Transfer functions were developed using the total soil Cd concentrations, soil pH, and SOM. They explained 56% of the variance for all samples irrespective of the vegetable genotypes. The transfer functions predicted the probability of exceeding China food safety standard concentrations for Cd in four major consumable vegetables under different soil conditions. Poor production practices in the study area involved usage of soil with pH values ≤ 5.5, especially for the cultivation of Raphanus sativus L., even with soil Cd concentrations below the China soil quality standard. We found the soil standard Cd concentrations for cultivating vegetables was not strict enough for strongly acidic (pH ≤ 5.5) and SOM-poor (SOM ≤ 10 g kg -1 ) soils present in southern China. It is thus necessary to address the effect of environmental variables to generate a suitable Cd threshold for cultivated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Copper, zinc, and cadmium in various fractions of soil and fungi in a Swedish forest.

PubMed

Vinichuk, Mykhailo M

2013-01-01

Ectomycorrhizal fungi profoundly affect forest ecosystems through mediating nutrient uptake and maintaining forest food webs. The accumulation of metals in each transfer step from bulk soil to fungal sporocarps is not well known. The accumulation of three metals copper (Cu), zinc (Zn) and cadmium (Cd) in bulk soil, rhizosphere, soil-root interface, fungal mycelium and sporocarps of mycorrhizal fungi in a Swedish forest were compared. Concentrations of all three metals increased in the order: bulk soil < soil-root interface (or rhizosphere) < fungal mycelium < fungal sporocarps. The uptake of Cu, Zn and Cd during the entire transfer process in natural conditions between soil and sporocarps occurred against a concentration gradient. In fungal mycelium, the concentration of all three metals was about three times higher than in bulk soil, and the concentration in sporocarps was about two times higher than in mycelium. In terms of accumulation, fungi (mycelium and sporocarps) preferred Cd to Zn and Cu. Zinc concentration in sporocarps and to a lesser extent in mycelium depended on the concentration in soil, whereas, the uptake of Cu and Cd by both sporocarps and mycelium did not correlate with metal concentration in soil. Heavy metal accumulation within the fungal mycelium biomass in the top forest soil layer (0-5 cm) might account for ca. 5-9% of the total amount of Cu, 5-11% of Zn, and 16-32% of Cd. As the uptake of zinc and copper by fungi may be balanced, this implied similarities in the uptake mechanism.

Cadmium Diagenesis in Polluted Sediments of a Tropical Estuary of SE Brazil

NASA Astrophysics Data System (ADS)

Patchineelam, S. R.; Metzger, E.; Jézéquel, D.; Sarazin, G.; Smoak, J. M.

2006-12-01

Sepetiba bay is a shallow semi enclosed water body located about 70km on the west side of the city of Rio de Janeiro with an area of 450km² separated from the Atlantic Ocean by a sand spit. Fishing, shrimp and tourism are important economic activities. During 35 years a Zinc/Cadmium smelter has polluted the bay. The objective of this investigation is to demonstrate how diagenetic processes are responsible for the cadmium remobilization out or fixation into the sediment column.. Two contrasting sites were selected to compare the diagenetic process. P1 located near to the smelter and P2 is about 20km away from the smelter next to a domestic effluents discharge into the bay. Peeper samplers with 25 cells with a resolution of 2,5cm were introduced into the sediment at both sites. After a period of 3 weeks equilibrium, the pore waters were separated from each cell and analyzed within 24 hours for alkalinity, H2S, NH3 and soluble phosphate by conventional methods An ICP-AES spectrometer was used to analyze Na, Mg, Li, Ba, Sr, Si, Fe and Mn. The total and labile Cd in pore waters were determined by differential-pulse stripping voltammetry. The solute profiles have revealed that the sediments at both sites were anoxic. The slopes of the ferrous and sulfide profile constituents permitted characterization the area at P1 as ferrous dominant with oxic conditions in the overlying water and P2 as a sulfidic rich environment with suboxic conditions in the water column. At P1 total dissolved Cd in the overlying water was about 450pM and labile fraction varied from 85 to 177pM. Just below the sediment water interface 695pM of total dissolved Cd was observed. Probably diagenetic processes are responsible for release of cadmium at the sediment interface. Below this maxima Cd concentrations decreased to 30pM. At P2 a concentration o of 150pM of total dissolved Cd was detected in the overlying water and samples in the pore waters at the sediment interface had an average concentration of 20pM. The downward diffusion of dissolved Cd in the pore water probably facilitated the formation of Cd sulfide or adsorption on particulate matter.

Morpho-Physiological and Proteome Level Responses to Cadmium Stress in Sorghum

PubMed Central

Kamal, Abu Hena Mostafa; Kim, Sang-Woo; Oh, Myeong-Won; Lee, Moon-Soon; Chung, Keun-Yook; Xin, Zhanguo; Woo, Sun-Hee

2016-01-01

Cadmium (Cd) stress may cause serious morphological and physiological abnormalities in addition to altering the proteome in plants. The present study was performed to explore Cd-induced morpho-physiological alterations and their potential associated mechanisms in Sorghum bicolor leaves at the protein level. Ten-day-old sorghum seedlings were exposed to different concentrations (0, 100, and 150 μM) of CdCl2, and different morpho-physiological responses were recorded. The effects of Cd exposure on protein expression patterns in S. bicolor were investigated using two-dimensional gel electrophoresis (2-DE) in samples derived from the leaves of both control and Cd-treated seedlings. The observed morphological changes revealed that the plants treated with Cd displayed dramatically altered shoot lengths, fresh weights and relative water content. In addition, the concentration of Cd was markedly increased by treatment with Cd, and the amount of Cd taken up by the shoots was significantly and directly correlated with the applied concentration of Cd. Using the 2-DE method, a total of 33 differentially expressed protein spots were analyzed using MALDI-TOF/TOF MS. Of these, treatment with Cd resulted in significant increases in 15 proteins and decreases in 18 proteins. Major changes were absorbed in the levels of proteins known to be involved in carbohydrate metabolism, transcriptional regulation, translation and stress responses. Proteomic results revealed that Cd stress had an inhibitory effect on carbon fixation, ATP production and the regulation of protein synthesis. Our study provides insights into the integrated molecular mechanisms involved in responses to Cd and the effects of Cd on the growth and physiological characteristics of sorghum seedlings. We have aimed to provide a reference describing the mechanisms involved in heavy metal damage to plants. PMID:26919231

Differential Metal Tolerance and Accumulation Patterns of Cd, Cu, Pb and Zn in the Liverwort Marchantia polymorpha L.

PubMed

Ares, Ángela; Itouga, Misao; Kato, Yukari; Sakakibara, Hitoshi

2018-03-01

In this study, we investigated the bioaccumulation, tissue distribution and physiological responses to different metal concentration (0.2 and 2 mM) and time of exposure of 1, 2 and 3 weeks with cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) using the model liverwort Marchantia polymorpha. Our data showed, on one hand, a significant enrichment and tissue translocation of Cu, Zn, and specially Cd, reaching concentrations of 1800 µg g - 1 in 3 weeks. On the other hand, Pb exhibited the lowest concentration values (50 µg g - 1 ), and 90% of the total concentration in the rhizoids. We could observe a positive correlation between tissue concentration, metal translocation and an enhanced toxic response. The results obtained in this study might contribute not only in the application of this species in environmental studies with heavy metals but also as a starting point to study the evolution of metal tolerance in land plants.

Estimation and influence of physicochemical properties and chemical fractions of surface sediment on the bioaccessibility of Cd and Hg contaminant in Langat River, Malaysia.

PubMed

Kadhum, Safaa A; Ishak, Mohd Yusoff; Zulkifli, Syaizwan Zahmir

2017-10-01

This study applied the use of sequential extraction technique and simple bioaccessibility extraction test to quantify the bioavailable fractions and the human bioaccessible concentration of metals collected from nine stations in surface sediment of the Langat River. The concentrations of total and bioaccessible metals from different stations were in the range of 0.49-1.04, 0.10-0.32 μg g -1 for T-Cd, Bio-Cd, respectively, and 12.9-128.03, 2.06-8.53 μg kg -1 for T-Hg, Bio-Hg, respectively. The results revealed highest R-Bio-Cd in Banting station (55.3 %), while the highest R-Bio-Hg was in Kajang station (49.61 %). The chemical speciation of Cd in most sampling stations was in the order of oxidisable-organic > residual > exchangeable > acid-reducible, while speciation of Hg was in the order of exchangeable > residual > oxidisable-organic > acid-reducible. The correlation matric of mean content showed that the TOM, particle size and Mg ++ in polluted surface sediments was highly correlated with total mercury. The PCA showed that the main factors influencing the bioaccessibility of Hg in surface sediments were the sediment TOM, F1 (EFLE) and F3 (oxidation-organic), while the factor influencing the bioaccessibility of Cd was the F3 (oxidation-organic) and T-Cd.

Effect of Arbuscular Mycorrhizal Fungi On Yield and Phytoremediation Performance of Pot Marigold (Calendula officinalis L.) Under Heavy Metals Stress.

PubMed

Tabrizi, Leila; Mohammadi, Siavash; Delshad, Mojtaba; Moteshare Zadeh, Babak

2015-01-01

In order to study the effect of mycorrhizal fungi (inoculated and non-inoculated) and heavy metals stress [0, Pb (150 and 300 mg/kg) and Cd (40 and 80 mg/kg)] on pot marigold (Calendula officinalis L.), a factorial experiment was conducted based on a randomized complete block design with 4 replications in Research Greenhouse of Department of Horticultural Sciences, University of Tehran, Iran, during 2012-2013. Plant height, herbal and flower fresh and dry weight, root fresh and dry weight and root volume, colonization percentage, total petal extract, total petal flavonoids, root and shoot P and K uptakes, and Pb and Cd accumulations in root and shoot were measured. Results indicated that with increasing soil Pb and Cd concentration, growth and yield of pot marigold was reduced significantly; Cd had greater negative impacts than Pb. However, mycorrhizal fungi alleviated these impacts by improving plant growth and yield. Pot marigold concentrated high amounts of Pb and especially Cd in its roots and shoots; mycorrhizal plants had a greater accumulation of these metals, so that those under 80 mg/kg Cd soil(-1) accumulated 833.3 and 1585.8 mg Cd in their shoots and roots, respectively. In conclusion, mycorrhizal fungi can improve not only growth and yield of pot marigold in heavy metal stressed condition, but also phytoremediation performance by increasing heavy metals accumulation in the plant organs.

Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96h) exposure to cadmium.

PubMed

Moncaleano-Niño, Angela M; Barrios-Latorre, Sergio A; Poloche-Hernández, Javier F; Becquet, Vanessa; Huet, Valérie; Villamil, Luisa; Thomas-Guyon, Hélène; Ahrens, Michael J; Luna-Acosta, Andrea

2017-04-01

Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5-5.0cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations≥100μg/L showed a significant increase, from 8.0 to 14.8μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96h of exposure to 1000μg/L Cd, were significantly lower (0.04mg P/g gonad) compared to control oysters (0.68mg P/g gonad), suggestive of an anti-estrogenic effect of Cd at high concentrations, whereas no significant changes in vitellogenin concentrations were observed at intermediate Cd exposure concentrations. This study confirms acute responses of metallothionein and vitellogenin concentrations in tissues of Saccostrea sp. exposed to high concentrations of cadmium (Cd≥100μg/L, 96h). The present results are first step towards validating the use of these two proteins as biomarkers of metal exposure in this species. Copyright © 2017 Elsevier B.V. All rights reserved.

2B4 expression on natural killer cells increases in HIV-1 infected patients followed prospectively during highly active antiretroviral therapy

PubMed Central

Ostrowski, S R; Ullum, H; Pedersen, B K; Gerstoft, J; Katzenstein, T L

2005-01-01

Human immunodeficiency virus (HIV)-1 infection influences natural killer (NK) cell expression of inhibitory NK receptors and activating natural cytotoxicity receptors. It is unknown whether expression of the co-stimulatory NK cell receptor 2B4 (CD244) on NK cells and CD3+ CD8+ cells are affected by highly active antiretroviral therapy (HAART), low-level viraemia, proviral-DNA or immune activation in HIV-1 infected patients. A total of 101 HAART-treated HIV-1 infected patients with ≤ 200 HIV-RNA copies/ml were followed prospectively for 24 months. HIV-RNA was investigated 3-monthly and 2B4 expression on CD3− CD16+ NK cells and CD3+ CD8+ cells, proviral-DNA and plasma soluble tumour necrosis factor receptor (sTNFr)-II were investigated 6-monthly. For comparison, 2B4 expression was investigated in 20 healthy individuals. The concentration of 2B4+ NK cells was initially reduced in HIV-1 infected patients (P < 0·001) but increased to a normal level during the 24 months’ follow-up. The concentration of CD3+ CD8+ 2B4+ cells in HIV-1 infected patients was normal and did not change during follow-up. The relative fluorescence intensity (RFI) of 2B4 increased on both NK cells and CD3+ CD8+ cells during follow-up (both P < 0·001). Higher levels of proviral-DNA carrying cells and plasma sTNFrII were associated with reductions in the concentration of 2B4+ NK cells (all P < 0·05). HIV-RNA had no effect on 2B4 expression on NK cells or CD3+ CD8+ cells. These findings demonstrate that the concentration of 2B4+ NK cells normalizes during long-term HAART in HIV-1 infected patients. The finding that proviral-DNA and sTNFrII were associated negatively with the concentration of 2B4+ NK cells suggests that immune activation in HIV-1 infected patients receiving HAART influences the target cell recognition by NK cells. PMID:16045743

2B4 expression on natural killer cells increases in HIV-1 infected patients followed prospectively during highly active antiretroviral therapy.

PubMed

Ostrowski, S R; Ullum, H; Pedersen, B K; Gerstoft, J; Katzenstein, T L

2005-09-01

Human immunodeficiency virus (HIV)-1 infection influences natural killer (NK) cell expression of inhibitory NK receptors and activating natural cytotoxicity receptors. It is unknown whether expression of the co-stimulatory NK cell receptor 2B4 (CD244) on NK cells and CD3+ CD8+ cells are affected by highly active antiretroviral therapy (HAART), low-level viraemia, proviral-DNA or immune activation in HIV-1 infected patients. A total of 101 HAART-treated HIV-1 infected patients with < or = 200 HIV-RNA copies/ml were followed prospectively for 24 months. HIV-RNA was investigated 3-monthly and 2B4 expression on CD3- CD16+ NK cells and CD3+ CD8+ cells, proviral-DNA and plasma soluble tumour necrosis factor receptor (sTNFr)-II were investigated 6-monthly. For comparison, 2B4 expression was investigated in 20 healthy individuals. The concentration of 2B4+ NK cells was initially reduced in HIV-1 infected patients (P < 0.001) but increased to a normal level during the 24 months' follow-up. The concentration of CD3+ CD8+ 2B4+ cells in HIV-1 infected patients was normal and did not change during follow-up. The relative fluorescence intensity (RFI) of 2B4 increased on both NK cells and CD3+ CD8+ cells during follow-up (both P < 0.001). Higher levels of proviral-DNA carrying cells and plasma sTNFrII were associated with reductions in the concentration of 2B4+ NK cells (all P < 0.05). HIV-RNA had no effect on 2B4 expression on NK cells or CD3+ CD8+ cells. These findings demonstrate that the concentration of 2B4+ NK cells normalizes during long-term HAART in HIV-1 infected patients. The finding that proviral-DNA and sTNFrII were associated negatively with the concentration of 2B4+ NK cells suggests that immune activation in HIV-1 infected patients receiving HAART influences the target cell recognition by NK cells.

Long-term field phytoextraction of zinc/cadmium contaminated soil by Sedum plumbizincicola under different agronomic strategies.

PubMed

Deng, Lin; Li, Zhu; Wang, Jie; Liu, Hongyan; Li, Na; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Christie, Peter

2016-01-01

In two long-term field experiments the zinc (Zn)/cadmium (Cd) hyperaccumulator Sedum plumbizincicola (S. plumbizincicola) was examined to optimize the phytoextraction of metal contaminated soil by two agronomic strategies of intercropping with maize (Zea mays) and plant densities. Soil total Zn and Cd concentrations decreased markedly after long-term phytoextraction. But shoot biomass and Cd and Zn concentrations showed no significant difference with increasing remediation time. In the intercropping experiment the phytoremediation efficiency in the treatment "S. plumbizincicola intercropped with maize" was higher than in S. plumbizincicola monocropping, and Cd concentrations of corn were below the maximum national limit. In the plant density experiment the phytoremediation efficiency increased with increasing plant density and 440,000 plants ha(-1) gave the maximum rate. These results indicated that S. plumbizincicola at an appropriate planting density and intercropped with maize can achieve high remediation efficiency to contaminated soil without affecting the cereal crop productivity. This cropping system combines adequate agricultural production with soil heavy metal phytoextraction.

Essential and toxic elements in seaweeds for human consumption.

PubMed

Desideri, D; Cantaluppi, C; Ceccotto, F; Meli, M A; Roselli, C; Feduzi, L

2016-01-01

Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, and I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by energy-dispersive polarized x-ray fluorescence spectrometry in 14 seaweeds purchased in local specialty stores in Italy and consumed by humans. The differences in elements between the algae species reached up to 2-4 orders of magnitude. Lithothamnium calcareum showed the highest levels of Ca, Al, Si, Fe, and Ti. Palmaria palmata showed the highest concentrations of K, Rb, and Cl. The highest content of S was in Chondrus crispus. Laminaria digitata contained the highest concentrations of total As, Cd, Sn, Br, and I. The highest concentration of Zn was in Chlorella pyrenoidosa. Ulva lactuca displayed the highest levels of Cu, Ni, Mn, and Pb. Iodine levels ranged from 3.4 in Chlorella pyrenoidosa to 7316 mg/kg(dry) in Laminaria digitata. The nutrimental importance of essential elements was assessed using nutritional requirements. The results showed that the consumption of algae might serve as an important source of the essential elements. Health risk due to the toxic elements present in seaweed was estimated using risk estimators. Total As, Cd, and Pb concentrations ranged from <1 to 67.6, to 7.2 and to 6.7 mg/kg(dry) respectively; therefore, their contribution to total elemental intake does not appear to pose any threat to the consumers, but the concentrations of these elements should be controlled to protect the consumer against potential adverse health risks.

Identification for the capability of Cd-tolerance, accumulation and translocation of 96 sorghum genotypes.

PubMed

Jia, Weitao; Miao, Fangfang; Lv, Sulian; Feng, Juanjuan; Zhou, Shufeng; Zhang, Xuan; Wang, Duoliya; Li, Shizhong; Li, Yinxin

2017-11-01

Cadmium (Cd) pollution is a worldwide environmental problem which heavily threatens human health and food security. Sorghum, as one of the most promising energy crop, has been considered to be the source of high-quality feedstock for ethanol fuel. Ninety-six sorghum genotypes were investigated under hydroponic conditions to compare their capabilities of Cd-tolerance, accumulation and translocation for their potential in remediation of Cd contamination. Different genotypes varied largely in the tolerance to Cd stress with tolerance indexes ranked from 0.107 to 0.933. Great difference was also found in Cd uptake and accumulation with concentrations ranging from 19.0 to 202.4mg/kg in shoots and 277.0-898.3mg/kg in roots. The total amounts of Cd ranked from 6.1 to 25.8μg per plant and the highest translocation factor was over 4 times higher than the lowest one. The correlation analysis demonstrated that Cd concentration in shoot reflected the ability of Cd translocation and tolerance of sorghum, and the path coefficient analysis indicated that root biomass could be taken as a biomarker to evaluate Cd extraction ability of sorghum. The results in this study can facilitate the restoring of Cd contaminated areas by sorghum. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of the Cd-bearing phases in municipal solid waste and biomass single fly ash particles using SR-microXRF spectroscopy.

PubMed

Camerani, Maria Caterina; Somogyi, Andrea; Vekemans, Bart; Ansell, Stuart; Simionovici, Alexandre S; Steenari, Britt-Marie; Panas, Itai

2007-09-01

By using an excitation energy of 27.0 keV, synchrotron radiation-induced micro-X-ray fluorescence (SR-microXRF) is employed to extract information regarding the composition and distribution of Cd-bearing phases in municipal solid waste (MSW) and biomass fly ashes. Significance of observation is based on statistics of totally more than 100 individual MSW and biomass fly ash particles from a fluidized bed combustion (FBC) plant. Cd concentrations in the parts-per-million range are determined. In general, although previous leaching studies have indicated Cd to be predominant in the smaller-size ash particles, in the present study Cd is more evenly distributed throughout all the particle sizes. For MSW fly ashes, results indicate the presence of Cd mainly as CdBr2 hot-spots, whereas for biomass fly ashes, which exhibit lower CdX2 concentration, a thin Cd layer on/in the particles is reported. For both ashes, Ca-containing matrixes are found to be the main Cd-bearing phases. Support for this observation is found from independent first-principles periodic density functional theory calculations. The observations are condensed into a schematic mechanism for Cd adsorption on the fly ash particles.

Phytoavailability and geospeciation of cadmium in contaminated soil remediated by Rhodobacter sphaeroides.

PubMed

Fan, Wenhong; Jia, Yingying; Li, Xiaomin; Jiang, Wei; Lu, Lin

2012-07-01

A microorganism was isolated from oil field injection water and identified as Rhodobacter sphaeroides. It was used for the remediation of simulated cadmium-contaminated soil. The phytoavailability of Cd was investigated through wheat seedling method to determine the efficiency of remediation. It was found that after remediation, the accumulation of Cd in wheat roots and leaves decreased by 67% and 53%, respectively. The Cd speciation in soil was determined with Tessier extraction procedure. It was found that the total Cd content in soil did not change during the experiments, but the geo-speciation of Cd changed remarkably. Among the five fractions, the concentration of exchangeable phases decreased by 27-46% and that of the phases bound to Fe-Mn oxides increased by 22-44%. The decrease of Cd accumulation in wheat showed significant positive correlation with the decrease of exchangeable phases. It could be concluded that the remediation of R. sphaeroides was carried out through the conversion of Cd to more stable forms. The decrease of sulfate concentration in supernatant indicated that the R. sphaeroides consumed sulfate. Copyright © 2012 Elsevier Ltd. All rights reserved.

Determination and evaluation of heavy metals in soils under two different greenhouse vegetable production systems in eastern China.

PubMed

Tian, Kang; Hu, Wenyou; Xing, Zhe; Huang, Biao; Jia, Mengmeng; Wan, Mengxue

2016-12-01

The evaluation of heavy metals (HMs) in greenhouse soils is crucial for both environmental monitoring and human health; thus, it is imperative to determine their concentrations, identify their sources and assess their potential risks. In this study, eight metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in 167 surface soils were investigated in two representative greenhouse vegetable systems of China: perennial solar greenhouse (SG) and seasonal plastic greenhouse (PG). The results indicated accumulations of Cd, Cu, Hg and Zn in the SG soils and Cd, Pb, Hg and Zn in the PG soils, with higher concentrations than the background values. In particular, Cd and Hg exhibited high levels of pollution under both GVP systems due to their positive Igeo values. Principle component analysis (PCA) and correlation analysis suggested that Cd, Cu, Hg and Zn in the SG soils and Cd, Hg and Zn in the PG soils were mainly related to intensive farming practices; Pb in the PG soils was significantly affected by atmospheric deposition. The results showed that soil characteristics, in particular soil organic matter, total nitrogen and total phosphorus, exerted significant influence on Hg, Cu, Cd, and Zn under the SG system. However, the HMs in the PG soils were weakly affected by soil properties. Overall, this study provides comparative research on the accumulation, potential risks and sources of HMs in two typical greenhouse soils in China, and our findings suggest that, Cd and Hg in both greenhouse soils could potentially represent environmental problems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decapitation improves the efficiency of Cd phytoextraction by Celosia argentea Linn.

PubMed

Liu, Jie; Zhang, Xuehong; Mo, Lingyun; Yao, Shiyin; Wang, Yixuan

2017-08-01

The effect of decapitation on enhancing plant growth and Cd accumulation in Celosia argentea Linn. was evaluated using a pot experiment. Decapitation significantly enhanced the growth of C. argentea. The numbers of branch and leaf in the decapitated plants (DP) were significantly higher than those in undecapitated plants (UDP, p < 0.05). Decapitation increased the biomass by 75%-105% for roots, 108%-152% for stems, and 80%-107% for leaves. Although the transpiration and photosynthesis rates were not significantly different between DP and UPD, decapitation significantly increased the total leaf area and total transpiration per plant (p < 0.05). The higher total transpiration per plant resulted in a higher leaf Cd concentration in DP. DP accumulated Cd in shoots (197, 275, and 425 μg plant -1 ) that were 2.5-2.8 times higher than UDP (78, 108, and 152 μg plant -1 ), with the soils containing 1, 5, and 10 mg kg -1 Cd. Results suggested that decapitation is a novel and convenient method to improve the phytoextraction efficiency of C. argentea in Cd contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Effect of phosphor on accumulation and chemical forms of cadmium, and physiological characterization in different varieties of Capsicum annuum L].

PubMed

Zhang, Xiao-Jing; Liu, Ji-Zhen; Xu, Wei-Hong; Chen, Gui-Qing; Wang, Hui-Xian; Zhang, Hai-Bo; Han, Gui-Qi; Zeng, Hong-Jun; Lan, Chun-Tao; Xiong, Zhi-Ting; Wei, Song-Qing

2011-04-01

Pot experiments were carried out to investigate the influence of different Phosphor (P) levels (0, 0.3% and 0.5%) on the plant growth, activities of antioxidant enzymes, accumulation and chemical forms of cadmium (Cd) in Capsicum annuum L. when exposed to Cd (10 mg x kg(-1)). The results showed that dry weights of leaf, fruit, roots and total dry weights of plant, and concentration and accumulation of Cd significantly differed between two varieties of Capsicum annuum L. Dry weights of fruit and total plant of Chaotianjiao increased by P (0.3% and 0.5%), while that of Yanjiao425 was inhibited. Activities of catalase (CAT) were increased at first, and then reduced in the presence of P; Activities of superoxide dismutase (SOD) and peroxidase (POD) of Chaotianjiao increased with increasing levels of P, but activities of SOD and POD of Yanjiao425 decreased with increasing levels of P. Chemical forms of Cd in fruit of Capsicum annuum L. were in order of F(NaCl) > F(HAC) > F(E) > Fr > F(HC) > F(W). The total extractable Cd, ethanol-extractable Cd, hydrochloric acid-extractable Cd and residual Cd in fruit of Ynajiao425 obviously decreased in the presence of P compared to the control, while the total extractable Cd, water-extractable Cd, acetic acid-extractable Cd and residual Cd in fruit of Chaotianjiao increased. Cadmium accumulations of Capsicum annuum L. were in order of roots > stew > leaf > fruit. Cadmium accumulations in fruit and plant of Yanjiao425 were decreased by 47.7% and 58.5% , 5.5% and 13. 1% in the presence of 0.3% and 0.5% P when exposed to Cd, and Cd accumulations in fruit and plant of Chaotianjiao were decreased by 23.6% in the presence of 0.3% P.

Can the shell of the green-lipped mussel Perna viridis from the west coast of Peninsular Malaysia be a potential biomonitoring material for Cd, Pb and Zn?

NASA Astrophysics Data System (ADS)

Yap, C. K.; Ismail, A.; Tan, S. G.; Abdul Rahim, I.

2003-07-01

The distributions of Cd, Pb and Zn in the total soft tissues and total shells of the green-lipped mussel Perna viridis were studied in field collected samples as well as from laboratory experimental samples. The results showed that Cd, Pb and Zn were readily accumulated in the whole shells. In mussels sampled from 12 locations along the west coast of Peninsular Malaysia, the ratios of the shell metals to the soft tissue metals were different at each sampling site. Nevertheless, the Cd and Pb levels in the shells were always higher than those in the soft tissues, while the Zn level was higher in the soft tissues than in the shells. In comparison with soft tissues, the degrees of variability for Pb and Cd concentrations in the shells were lower. The lower degrees of variability and significant ( P<0.05) correlation coefficients of Cd and Pb within the shells support the use of the mussel shell as a suitable biomonitoring material for the two metals rather than the soft tissue since this indicated that there is more precision (lower CV) in the determination of metal concentrations in the shell than in the soft tissue. Experimental work showed that the pattern of depuration in the shell was not similar to that of the soft tissue although their patterns of accumulation were similar. This indicated that the depuration of heavy metals in the shell was not affected by the physiological conditions of the mussels. Although Zn could be regulated by the soft tissue, the incorporated Cd, Pb and Zn remained in the shell matrices. The present results support the use of the total shell of P. viridis as a potential biomonitoring material for long-term contamination of Cd, Pb and Zn.

Effects of elevated CO2 levels on root morphological traits and Cd uptakes of two Lolium species under Cd stress*

PubMed Central

Jia, Yan; Tang, Shi-rong; Ju, Xue-hai; Shu, Li-na; Tu, Shu-xing; Feng, Ren-wei; Giusti, Lorenzino

2011-01-01

This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam. and Lolium perenne L. exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0, 4, and 16 mg/L) under hydroponic conditions. The results show that elevated levels of CO2 increased shoot biomass more, compared to root biomass, but decreased Cd concentrations in all plant tissues. Cd exposure caused toxicity to both Lolium species, as shown by the restrictions of the root morphological parameters including root length, surface area, volume, and tip numbers. These parameters were significantly higher under elevated levels of CO2 than under ambient CO2, especially for the number of fine roots. The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress, suggesting an ameliorated Cd stress under elevated levels of CO2. The total Cd uptake per pot, calculated on the basis of biomass, was significantly greater under elevated levels of CO2 than under ambient CO2. Ameliorated Cd toxicity, decreased Cd concentration, and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation. PMID:21462388

Biostabilization of cadmium contaminated sediments using indigenous sulfate reducing bacteria: Efficiency and process.

PubMed

Peng, Weihua; Li, Xiaomin; Liu, Tong; Liu, Yingying; Ren, Jinqian; Liang, Dawei; Fan, Wenhong

2018-06-01

Sulfate reducing bacteria (SRB) was used to stabilize cadmium (Cd) in sediments spiked with Cd. The study found that the Cd in sediments (≤600 mg kg -1 ) was successfully stabilized after 166 d SRB bio-treatment. This was verified by directly and indirectly examining Cd speciation in sediments, mobilization index, and Cd content in interstitial water. After 166 d bio-treatment, compared with control groups, Cd concentrations in interstitial water of Cd-spiked sediments were reduced by 77.6-96.4%. The bioavailable fractions of Cd (e.g., exchangeable and carbonate bound phases) were reduced, while more stable fractions of Cd (e.g., Fe-Mn oxide, organic bound, and residual phases) were increased. However, Cd mobilization in sediment was observed during the first part of bio-treatment (32 d), leading to an increase of Cd concentrations in the overlying water. Bacterial community composition (e.g., richness, diversity, and typical SRB) played an important role in Cd mobilization, dissolution, and stabilization. Bacterial community richness and diversity, including the typical SRB (e.g., Desulfobacteraceae and Desulfobulbaceae), were enhanced. However, bacterial communities were also influenced by Cd content and its speciations (especially the exchangeable and carbonate bound phases) in sediments, as well as total organic carbon in overlying water. Copyright © 2018 Elsevier Ltd. All rights reserved.

Distribution of Cd, Pb, Zn and Cu and their chemical speciations in soils from a peri-smelter area in northeast China

NASA Astrophysics Data System (ADS)

Du, Ping; Xue, Nandong; Liu, Li; Li, Fasheng

2008-07-01

An exploratory study on soil contamination of heavy metals was carried out surrounding Huludao zinc smelter in Liaoning province, China. The distribution of total heavy metals and their chemical speciations were investigated. The correlations between heavy metal speciations and soil pH values in corresponding sites were also analyzed. In general, Cd, Zn, Pb, Cu and As presented a significant contamination in the area near the smelter, comparied with Environmental Quality Standards for Soils in China. The geoaccumulation index showed the degree of contamination: Cd > Zn > Pb > Cu > As. There was no obvious pollution of Cr and Ni in the studied area. The speciation analysis showed that the dominant fraction of Cd and Zn was the acid soluble fraction, and the second was the residual fraction. Pb was mostly associated with the residual fraction, which constituted more than 50% of total concentration in all samples. Cu in residual fraction accounted for a high percentage (40-80%) of total concentration, and the proportion of Cu in the oxidizable fraction is higher than that of other metals. The distribution pattern of Pb and Zn was obviously affected by soil pH. It seemed that Pb and Zn content in acid solution fraction increased with increasing soil pH values, while Cd content in acid soluble fraction accounted for more proportion in neutral and alkaline groups than acidic one. The fraction distribution patterns of Cu in three pH groups were very similar and independent of soil pH values. And the residual fraction of Cu took a predominant part (50%) of the total content.

Phytoavailability of Cadmium (Cd) to Pak Choi (Brassica chinensis L.) Grown in Chinese Soils: A Model to Evaluate the Impact of Soil Cd Pollution on Potential Dietary Toxicity

PubMed Central

Yang, Xiaoe; Xiao, Wendan; Stoffella, Peter J.; Saghir, Aamir; Azam, Muhammad; Li, Tingqiang

2014-01-01

Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg−1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg−1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production. PMID:25386790

Phytoavailability of cadmium (Cd) to Pak choi (Brassica chinensis L.) grown in Chinese soils: a model to evaluate the impact of soil Cd pollution on potential dietary toxicity.

PubMed

Rafiq, Muhammad Tariq; Aziz, Rukhsanda; Yang, Xiaoe; Xiao, Wendan; Stoffella, Peter J; Saghir, Aamir; Azam, Muhammad; Li, Tingqiang

2014-01-01

Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg-1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg-1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production.

Dietary determinants of cadmium exposure in the Strong Heart Family Study

PubMed Central

Olmedo, Pablo; Grau-Perez, Maria; Fretts, Amanda; Tellez-Plaza, Maria; Gil, Fernando; Yeh, Fawn; Umans, Jason G.; Francesconi, Kevin A.; Goessler, Walter; Franceschini, Nora; Lee, Elisa T.; Best, Lyle G.; Cole, Shelley A.; Howard, Barbara V.; Navas-Acien, Ana

2017-01-01

Urinary cadmium (Cd) concentrations in the Strong Heart Family Study (SHFS) participants are higher than in the general US population. This difference is unlikely to be related to tobacco smoking. We evaluated the association of consumption of processed meats and other dietary products with urinary Cd concentrations in the SHFS, a family-based study conducted in American Indian communities. We included 1725 participants with urine Cd concentrations (standardized to urine creatinine) and food frequency questionnaire data grouped in 24 categories, including processed meat. Median (IQR) urinary Cd concentrations were 0.44 (0.20–0.85) μg/g creatinine. The age, sex, smoking, education, center, body mass index, and total kcal adjusted geometric mean ratio (GMR) (95%CI) of urinary cadmium concentrations per IQR increase in each dietary category was 1.16 (1.04–1.29) for processed meat, 1.10 (1.00–1.21) for fries and chips, 0.87 (0.80–0.95) for dairy products, and 0.89 (0.82–0.97) for fruit juices. The results remained similar after further adjustment for the dietary categories associated with urinary Cd in the previous model except for fries and chips, which was no longer statistically significant. These findings revealed the potential importance of processed meat products as a dietary source of cadmium. PMID:28012896

Amelioration and degradation of pressmud and bagasse wastes using vermitechnology.

PubMed

Bhat, Sartaj Ahmad; Singh, Jaswinder; Vig, Adarsh Pal

2017-11-01

This study evaluated the amelioration of pressmud (PM) and bagasse (BG) wastes by the vermiremediation process. The wastes were spiked with cattle dung (CD) in different concentrations to find out the best proportion supporting maximum earthworm growth and nutrients availability. The highest growth rate was observed in PMBG 50 (282.2mg/d/worm) feed mixture. Response surface design of earthworm growth parameters enumerated best concentration of wastes in CD with maximum value of 21.81% for earthworm number, 30.86% for earthworm weight, 27.09% for cocoons, 29.71% for hatchlings and 34.0% for hatchlings weight. Vermicomposting enhanced nutrient parameters like pH (6-8%), total kjeldahl nitrogen (19-48%), total phosphorus (9-67%), total calcium (13-111%), while decrease in total organic carbon (14-32%), electrical conductivity (21-30%), C:N ratio (36-51%), total potassium (9-19%) and total sodium (3-21%). Heavy metals in the final products were found to be under safe limits. SEM micrographs were more fragmented which indicated maturity and stability. Copyright © 2017 Elsevier Ltd. All rights reserved.

The negative effects of cadmium on Bermuda grass growth might be offset by submergence.

PubMed

Tan, Shuduan; Huang, Huang; Zhu, Mingyong; Zhang, Kerong; Xu, Huaqin; Wang, Zhi; Wu, Xiaoling; Zhang, Quanfa

2013-10-01

Revegetation in the water-level-fluctuation zone (WLFZ) could stabilize riverbanks, maintain local biodiversity, and improve reservoir water quality in the Three Gorges Reservoir Region (TGRR). However, submergence and cadmium (Cd) may seriously affect the survival of transplantations. Bermuda grass (Cynodon dactylon) is a stoloniferous and rhizomatous prostrate weed displaying high growth rate. A previous study has demonstrated that Bermuda grass can tolerate deep submergence and Cd stress, respectively. In the present study, we further analyzed physiological responses of Bermuda grass induced by Cd-and-submergence stress. The ultimate goal was to explore the possibility of using Bermuda grass for revegetation in the WLFZ of China's TGRR and other riparian areas. The Cd-and-submergence-treated plants had higher malondialdehyde contents and peroxidase than control, and both increased with the Cd concentration increase. All treated plants catalase activity increased with the experimental duration increases, and their superoxide dismutase also gradually increased with the Cd concentration from 1 day to 15 days. Total biomass of the same Cd-and-submergence plants increased along the experimental duration as well. Plants exposed to Cd-and-submergence stress showed shoot elongation. The heights of all treated plants were taller than those of the control. Leaf chlorophyll contents, maximum leaf length, and soluble sugars contents of all the Cd-and-submergence-treated plants were more than those of the untreated control. Although Cd inhibits plants growth, decreases chlorophyll and biomass content, and with the submergence induced the leaf and shoot elongation, more part of the Cd-and-submergence stress plants appeared in the air, exhibited fast growth with maintenance of leaf color, which guaranteed the plants' photosynthesis, and ensured the total biomass and carbohydrate sustainability, further promoting Cd-and-submergence tolerance. The results imply that the negative effects of cadmium on Bermuda grass growth might be offset by submergence.

Spatial variability of soil total and DTPA-extractable cadmium caused by long-term application of phosphate fertilizers, crop rotation, and soil characteristics.

PubMed

Jafarnejadi, A R; Sayyad, Gh; Homaee, M; Davamei, A H

2013-05-01

Increasing cadmium (Cd) accumulation in agricultural soils is undesirable due to its hazardous influences on human health. Thus, having more information on spatial variability of Cd and factors effective to increase its content on the cultivated soils is very important. Phosphate fertilizers are main contamination source of cadmium (Cd) in cultivated soils. Also, crop rotation is a critical management practice which can alter soil Cd content. This study was conducted to evaluate the effects of long-term consumption of the phosphate fertilizers, crop rotations, and soil characteristics on spatial variability of two soil Cd species (i.e., total and diethylene triamine pentaacetic acid (DTPA) extractable) in agricultural soils. The study was conducted in wheat farms of Khuzestan Province, Iran. Long-term (27-year period (1980 to 2006)) data including the rate and the type of phosphate fertilizers application, the respective area, and the rotation type of different regions were used. Afterwards, soil Cd content (total or DTPA extractable) and its spatial variability in study area (400,000 ha) were determined by sampling from soils of 255 fields. The results showed that the consumption rate of di-ammonium phosphate fertilizer have been varied enormously in the period study. The application rate of phosphorus fertilizers was very high in some subregions with have extensive agricultural activities (more than 95 kg/ha). The average and maximum contents of total Cd in the study region were obtained as 1.47 and 2.19 mg/kg and DTPA-extractable Cd as 0.084 and 0.35 mg/kg, respectively. The spatial variability of Cd indicated that total and DTPA-extractable Cd contents were over 0.8 and 0.1 mg/kg in 95 and 25 % of samples, respectively. The spherical model enjoys the best fitting and lowest error rate to appraise the Cd content. Comparing the phosphate fertilizer consumption rate with spatial variability of the soil cadmium (both total and DTPA extractable) revealed the high correlation between the consumption rate of P fertilizers and soil Cd content. Rotation type was likely the main effective factor on variations of the soil DTPA-extractable Cd contents in some parts (eastern part of study region) and could explain some Cd variation. Total Cd concentrations had significant correlation with the total neutralizing value (p < 0.01), available P (p < 0.01), cation exchange capacity (p < 0.05), and organic carbon (p < 0.05) variables. The DTPA-extractable Cd had significant correlation with OC (p < 0.01), pH, and clay content (p < 0.05). Therefore, consumption rate of the phosphate fertilizers and crop rotation are important factors on solubility and hence spatial variability of Cd content in agricultural soils.

Trace element mobility and transfer to vegetation within the Ethiopian Rift Valley lake areas.

PubMed

Kassaye, Yetneberk A; Skipperud, Lindis; Meland, Sondre; Dadebo, Elias; Einset, John; Salbu, Brit

2012-10-26

To evaluate critical trace element loads in native vegetation and calculate soil-to-plant transfer factors (TFs), 11 trace elements (Cr, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb and Mn) have been determined in leaves of 9 taxonomically verified naturally growing terrestrial plant species as well as in soil samples collected around 3 Ethiopian Rift Valley lakes (Koka, Ziway and Awassa). The Cr concentration in leaves of all the plant species was higher than the "normal" range, with the highest level (8.4 mg per kg dw) being observed in Acacia tortilis from the Lake Koka area. Caper species (Capparis fascicularis) and Ethiopian dogstooth grass (Cynodon aethiopicus) from Koka also contained exceptionally high levels of Cd (1 mg per kg dw) and Mo (32.8 mg per kg dw), respectively. Pb, As and Cu concentrations were low in the plant leaves from all sites. The low Cu level in important fodder plant species (Cynodon aethiopicus, Acacia tortilis and Opuntia ficus-indicus) implies potential deficiency in grazing and browsing animals. Compared to the Canadian environmental quality guideline and maximum allowable concentration in agricultural soils, the total soil trace element concentrations at the studied sites are safe for agricultural crop production. Enrichment factor was high for Zn in soils around Lakes Ziway and Awassa, resulting in moderate to high transfer of Zn to the studied plants. A six step sequential extraction procedure on the soils revealed a relatively high mobility of Cd, Se and Mn. Strong association of most trace elements with the redox sensitive fraction and mineral lattice was also confirmed by partial redundancy analysis. TF (mg per kg dw plants/mg per kg dw soil) values based on the total (TF(total)) and mobile fractions (TF(mobile)) of soil trace element concentrations varied widely among elements and plant species, with the averaged TF(total) and TF(mobile) values ranging from 0.01-2 and 1-60, respectively. Considering the mobile fraction in soils should be available to plants, TF(mobile) values could reflect trace elements transfer to plants in the most realistic way. However, the present study indicates that TF(total) values also reflect the transfer of elements such as Mn, Cd and Se to plants more realistically than TF(mobile) values did.

Combining cross flow ultrafiltration and diffusion gradients in thin-films approaches to determine trace metal speciation in freshwaters

NASA Astrophysics Data System (ADS)

Liu, Ruixia; Lead, Jamie R.; Zhang, Hao

2013-05-01

Cross flow ultrafiltration (CFUF) and diffusive gradients in thin films (DGT) with open pore gel (OP) and restricted pore gel (RP) were used to measure trace metal speciation in selected UK freshwaters. The proportions of metals present in particulate forms (>1 μm) varied widely between 40-85% Pb, 60-80% Al, 7-56% Mn, 10-49% Cu, 0-55% Zn, 20-38% Cr, 20-30% Fe, 6-25% Co, 5-22% Cd and <7% Ni. In the colloidal fraction (2 kDa-1 μm) values varied between 53-91% Pb, 33-55% Al, 21-55% Cu, 20-44% Fe, 34-36% Cr, 20-40% Cd, 7-28% Co and Ni, 2-32% Zn and <8% Mn. Wide variations were also observed in the ultrafiltered fraction (<2 kDa). These results indicated that colloids indeed influenced the occurrence and transport of Al, Fe, Cr, Co, Ni, Cu, Zn, Cr and Pb metals in rivers, while inorganic or organic colloids did not exert an important control on Mn transport in the selected freshwaters. Of total species, total labile metal measured by DGT-OP accounted for 1.4-50% for Al, Fe, Co, Ni, Cu, Cd and Pb in all selected waters. Of these metals total labile Pb concentration was the lowest with value less than 1.4% although this value slightly increased after deducting particulate fractions. In some waters, a majority of total Mn, Zn and Cr is DGT labile, in which the DGT labile Mn fraction accounted for 98-118% of the total dissolved phase. In most cases, the inorganic labile concentration measured by DGT-RP was lower than the total labile metal concentration. By the combination of CFUF and DGT techniques, the concentrations of total labile and inorganic labile metal species in CFUF-derived truly dissolved phase were measured in four water samples. 100% of ultrafiltered Mn species was found to be total DGT labile. The proportions of total labile metal species were lower than those of ultrafiltered fraction for Al, Fe, Co, Ni, Cu, Cd and Pb in all selected waters, and Cr and Zn in some cases, indicating a large amount of natural complexing ligands with smaller size for the metals to form kinetically inert species or thermodynamically stable complexes. Observed discrepancies in metal speciation between metals and within sampling sites were related to the differences in the characteristics of the metals and the nature of water sources.

Phytoavailability and phytovariety codetermine the bioaccumulation risk of heavy metal from soils, focusing on Cd-contaminated vegetable farms around the Pearl River Delta, China.

PubMed

Hu, Junli; Wu, Fuyong; Wu, Shengchun; Sun, Xiaolin; Lin, Xiangui; Wong, Ming Hung

2013-05-01

Five random vegetable farms were selected to investigate the bioaccumulation risk of heavy metals (HMs) by different type of vegetables around the Pearl River Delta (PRD), China. The concentration order of four major HMs in the surface soil samples was Cd

Integration of Cadmium Accumulation, Subcellular Distribution, and Physiological Responses to Understand Cadmium Tolerance in Apple Rootstocks

PubMed Central

Zhou, Jiangtao; Wan, Huixue; He, Jiali; Lyu, Deguo; Li, Huifeng

2017-01-01

Cadmium (Cd) is a nonessential and highly toxic element causing agricultural problems. However, little information is available about the variation in Cd tolerance among apple rootstocks and its underlying physiological regulation mechanisms. This study investigated Cd accumulation, subcellular distribution, and chemical forms as well as physiological changes among four apple rootstocks exposed to either 0 or 300 μM CdCl2. The results showed that variations in Cd tolerance existed among these rootstocks. Cd exposure caused decline in photosynthesis, chlorophyll and biomass in four apple rootstocks, which was less pronounced in M. baccata, indicating its higher Cd tolerance. This finding was corroborated with higher Cd tolerance indexes (TIs) of the whole plant in M. baccata than those in the other three apple rootstocks. Among the four apple rootstocks, M. baccata displayed the lowest Cd concentrations in roots, wood, and leaves, the smallest total Cd amounts as well as the lowest BCF. In apple rootstocks, it was found that to immobilize Cd in cell wall and soluble fraction (most likely in vacuole) and to convert it into pectate- or protein- integrated forms and undissolved Cd phosphate forms may be the primary strategies to reduce Cd mobility and toxicity. The physiological changes including ROS, carbohydrates and antioxidants were in line with the variations of Cd tolerance among four apple rootstocks. In comparison with the other three apple rootstocks, M. baccata had lower concentrations of ROS in roots and bark, H2O2 in roots and leaves and MDA in roots, wood and bark, but higher concentrations of soluble sugars in bark and starch in roots and leaves, and enhanced antioxidants. These results indicate that M. baccata are more tolerant to Cd stress than the other three apple rootstocks under the current experiment conditions, which is probably related to Cd accumulation, subcellular partitioning and chemical forms of Cd and well-coordinated antioxidant defense mechanisms. PMID:28638400

Inhibition of cadmium ion uptake in rice (Oryza sativa) cells by a wall-bound form of silicon.

PubMed

Liu, Jian; Ma, Jie; He, Congwu; Li, Xiuli; Zhang, Wenjun; Xu, Fangsen; Lin, Yongjun; Wang, Lijun

2013-11-01

The stresses acting on plants that are alleviated by silicon (Si) range from biotic to abiotic stresses, such as heavy metal toxicity. However, the mechanism of stress alleviation by Si at the single-cell level is poorly understood. We cultivated suspended rice (Oryza sativa) cells and protoplasts and investigated them using a combination of plant nutritional and physical techniques including inductively coupled plasma mass spectrometry (ICP-MS), the scanning ion-selective electrode technique (SIET) and X-ray photoelectron spectroscopy (XPS). We found that most Si accumulated in the cell walls in a wall-bound organosilicon compound. Total cadmium (Cd) concentrations in protoplasts from Si-accumulating (+Si) cells were significantly reduced at moderate concentrations of Cd in the culture medium compared with those from Si-limiting (-Si) cells. In situ measurement of cellular fluxes of the cadmium ion (Cd(2+) ) in suspension cells and root cells of rice exposed to Cd(2+) and/or Si treatments showed that +Si cells significantly inhibited the net Cd(2+) influx, compared with that in -Si cells. Furthermore, a net negative charge (charge density) within the +Si cell walls could be neutralized by an increase in the Cd(2+) concentration in the measuring solution. A mechanism of co-deposition of Si and Cd in the cell walls via a [Si-wall matrix]Cd co-complexation may explain the inhibition of Cd ion uptake, and may offer a plausible explanation for the in vivo detoxification of Cd in rice. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Strategies for Cd accumulation in Dittrichia viscosa (L.) Greuter: role of the cell wall, non-protein thiols and organic acids.

PubMed

Fernández, R; Fernández-Fuego, D; Bertrand, A; González, A

2014-05-01

Dittrichia viscosa (L.) Greuter is plant species commonly found in degraded zones of Asturias (Spain), where it accumulates high levels of Cd, but the mechanisms involved in this response in non-model plants have not been elucidated. In this way, we analysed the fraction of the total Cd bound to the cell walls, the ultrastructural localization of this metal, and non-protein thiol and organic acid concentrations of two clones of D. viscosa: DV-A (from a metal-polluted soil) and DV-W (from a non-polluted area). After 10 days of hydroponic culture with Cd, fractionation and ultrastructural localisation studies showed that most of the Cd accumulated by D. viscosa was kept in the cell wall. The non-protein thiol content rose in D. viscosa with Cd exposure, especially in the non-metallicolous DV-W clone, and in both clones we found with Cd exposure a synthesis de novo of phytochelatins PC2 and PC3 in shoots and roots and also of other phytochelatin-related compounds, particularly in roots. Regarding organic acids, their concentration in both clones decreased in shoots after Cd treatment, but increased in roots, mainly due to changes in the citric acid concentration. Thus, retention of Cd in the cell wall seems to be the first strategy in response to metal entry in D. viscosa and once inside cells non-protein thiols and organic acids might also participate in Cd tolerance. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

A comparison of physiological indicators of sublethal cadmium stress in wetland plants

USGS Publications Warehouse

Mendelssohn, I.A.; McKee, K.L.; Kong, T.

2001-01-01

Physiological indices, including photosynthesis, chlorophyll fluorescence, adenylate energy charge (AEC) ratio, and leaf reflectance, were determined for Typha domingensis and Spartina alterniflora in response to increasing concentrations of Cd and compared with the growth responses of these species. Leaf expansion, the live/total ratio of plant aboveground biomass, and the aboveground regrowth rate after the initial harvests were significantly reduced with increasing Cd concentration in the growth medium. Of the four physiological responses measured, only photosynthesis and AEC responded to the Cd treatment before damage was visually apparent. Also, these indices were significantly correlated with leaf expansion rate and live/total ratio in most instances. Except at the end of the experiment, when the most stressed plants began to die, the Fv/Fm ratio was not significantly affected by the Cd treatment. The leaf spectral reflectance parameters showed no significant change during the entire treatment period. The significant correlation between the stress indicators and plant growth supported the findings that photosynthesis and AEC were the most responsive of the indicators tested, however, further research investigating other chlorophyll fluorescence and leaf reflectance parameters may demonstrate as well the value of these indicators in quantifying sublethal stress. ?? 2001 Elsevier Science B.V. All rights reserved.

Interaction of Cd and Zn toxicity for Folsomia candida Willem (Collembola: Isotomidae) in relation to bioavailability in soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Gestel, C.A.M.; Hensbergen, P.J.

1997-06-01

The use of toxicity tests in which each chemical is tested separately is inadequate for assessing the potential risk of complex mixtures of chemicals for soil ecosystems. In the present study, the effects of Cd and Zn, alone or in combination, on the survival, growth, and reproduction of the collembolan Folsomia candida were determined after 2, 4, and 6 weeks of exposure in an artificial soil. The water solubility of Cd in the soil was significantly increased by the presence of Zn, whereas Cd did not affect the water solubility of Zn. In spite of this, uptake of Cd ormore » Zn in the animals was not affected by the presence of the other metal, suggesting that water solubility does not determine the uptake of these metals in F. candida. For both Cd and Zn, reproduction was the most sensitive parameter, with 50% effective concentration (EC50) values of 51 and 683 {micro}g/g dry soil, respectively, after 6 weeks. These values corresponded with internal concentrations of 44 {micro}g Cd/g and 14 {micro}g Zn/g dry soil, respectively. Although a proper comparison of the effects of mixtures of the metals with the effects of the individual metals was sometimes hampered by the nonsimilarity of dose-response relationships, it may be concluded that the effects of the mixture of Cd and Zn on the growth of F. candida are antagonistic (EC50 significantly greater than 1.0 toxic unit), while the effects on reproduction are additive (EC50 = 1.0 toxic unit). Similar conclusions could be drawn for EC50s expressed on the basis of total and water-soluble soil concentrations as well as on the basis of internal concentrations in animals. Analysis of the combined effects of Cd and Zn at the 10% effective concentration level did not change these conclusions.« less

Assessment of heavy metal pollution in vegetables and relationships with soil heavy metal distribution in Zhejiang province, China.

PubMed

Ye, Xuezhu; Xiao, Wendan; Zhang, Yongzhi; Zhao, Shouping; Wang, Gangjun; Zhang, Qi; Wang, Qiang

2015-06-01

There are increasing concerns on heavy metal contaminant in soils and vegetables. In this study, we investigated heavy metal pollution in vegetables and the corresponding soils in the main vegetable production regions of Zhejiang province, China. A total of 97 vegetable samples and 202 agricultural soil samples were analyzed for the concentrations of Cd, Pb, As, Hg, and Cr. The average levels of Cd, Pb, and Cr in vegetable samples [Chinese cabbage (Brassica campestris spp. Pekinensis), pakchoi (Brassica chinensis L.), celery (Apium graveolens), tomato (Lycopersicon esculentum), cucumber (Colletotrichum lagenarium), cowpea (Vigna unguiculata), pumpkin (Cucurbita pepo L.), and eggplant (Solanum melongena)] were 0.020, 0.048, and 0.043 mg kg(-1), respectively. The Pb and Cr concentrations in all vegetable samples were below the threshold levels of the Food Quality Standard (0.3 and 0.5 mg kg(-1), respectively), except that two eggplant samples exceeded the threshold levels for Cd concentrations (0.05 mg kg(-1)). As and Hg contents in vegetables were below the detection level (0.005 and 0.002 mg kg(-1), respectively). Soil pollution conditions were assessed in accordance with the Chinese Soil Quality Criterion (GB15618-1995, Grade II); 50 and 68 soil samples from the investigated area exceeded the maximum allowable contents for Cd and Hg, respectively. Simple correlation analysis revealed that there were significantly positive correlations between the metal concentrations in vegetables and the corresponding soils, especially for the leafy and stem vegetables such as pakchoi, cabbage, and celery. Bio-concentration factor values for Cd are higher than those for Pb and Cr, which indicates that Cd is more readily absorbed by vegetables than Pb and Cr. Therefore, more attention should be paid to the possible pollution of heavy metals in vegetables, especially Cd.

Heavy metal concentrations in redeveloping soil of mine spoil under plantations of certain native woody species in dry tropical environment, India.

PubMed

Singh, Anand N; Zeng, De-hui; Chen, Fu-sheng

2005-01-01

Total concentration of heavy metals (Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5-yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.

Immobilization of Pb, Cd, and Zn in a contaminated soil using eggshell and banana stem amendments: metal leachability and a sequential extraction study.

PubMed

Ashrafi, Mehrnaz; Mohamad, Sharifah; Yusoff, Ismail; Shahul Hamid, Fauziah

2015-01-01

Heavy-metal-contaminated soil is one of the major environmental pollution issues all over the world. In this study, two low-cost amendments, inorganic eggshell and organic banana stem, were applied to slightly alkaline soil for the purpose of in situ immobilization of Pb, Cd, and Zn. The artificially metal-contaminated soil was treated with 5% eggshell or 10% banana stem. To simulate the rainfall conditions, a metal leaching experiment for a period of 12 weeks was designed, and the total concentrations of the metals in the leachates were determined every 2 weeks. The results from the metal leaching analysis revealed that eggshell amendment generally reduced the concentrations of Pb, Cd, and Zn in the leachates, whereas banana stem amendment was effective only on the reduction of Cd concentration in the leachates. A sequential extraction analysis was carried out at the end of the experiment to find out the speciation of the heavy metals in the amended soils. Eggshell amendment notably decreased mobility of Pb, Cd, and Zn in the soil by transforming their readily available forms to less accessible fractions. Banana stem amendment also reduced exchangeable form of Cd and increased its residual form in the soil.

Cadmium, Chromium, and Copper Concentration plus Semen-Quality in Environmental Pollution Site, China

PubMed Central

LI, Yan; GAO, Qiaoyan; LI, Mingcai; LI, Mengyang; GAO, Xueming

2014-01-01

Abstract Background The environmental pollution is one of the factors contributing to the decrease of sperm quality for human beings. The aim of this study was to assess cadmium (Cd), chromium (Cr), and copper (Cu) concentration of man in environmental pollution site, and explore relationships between men exposure to Cd, Cr, and Cu and semen-quality parameters in environmental pollution site. Methods Ninety five men were recruited through pollution area and controls in 2011. We measured semen quality using Computer-aided Semen Quality Analysis, and Cd, Cr, and Cu levels in seminal plasma using Graphite Gurnace Atomic Absorption Spectroscopy. Spearman rank correlation analysis was used to evaluate the correlation between Cd, Cr and Cu concentration in seminal plasma and semen quality. Results The mean of seminal plasma Cd, Cr, and Cu values in pollution area was higher than the controls. Seminal plasma Cr values displayed a significant negative correlation with total motility and normomorph sperm rate. Seminal plasma Cu values also displayed a negative correlation with normomorph sperm rate. Conclusions Male reproductive health may be threatened by environmental pollution, and it may be influence local population diathesis. PMID:26060677

Monitoring of essential and heavy metals in green tea from different geographical origins.

PubMed

Brzezicha-Cirocka, Justyna; Grembecka, Małgorzata; Szefer, Piotr

2016-03-01

The present study measured the concentrations of toxic metals (Cd, Pb) and other elements (Ca, K, Mg, Na, P, Mn, Fe, Zn, Cu, Co, Cr, Ni) in tea leaves and their infusions. The total metal contents were determined by atomic absorption spectrometry. Phosphorus concentration was determined using an ultraviolet-visible spectrophotometer. Assessment of the mineral composition enabled determination of the leaching percentage and the risk of exceeding provisional tolerable weekly intake for Cd through daily tea consumption. The concentrations of bioelements were analyzed based on the recommended daily intake values for each. According to recently established standards, green tea was found to be a rich source of Mn. The average Pb and Cd levels in a 200-mL beverage were 0.002 and 0.003 mg, respectively. Indian teas had the highest percentage of Cd leaching (43.8%) and Chinese tea had the lowest (9.41%). Multivariate analysis techniques such as factor analysis and cluster analysis were used to differentiate samples according to geographical origin (China, India, or Japan). Potassium, P, Mn, Fe, Cu, Co, and Cd were effective descriptors for the identification of tea samples from China, India, and Japan.

Trace-elements, methylmercury and metallothionein levels in Magellanic penguin (Spheniscus magellanicus) found stranded on the Southern Brazilian coast.

PubMed

Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tércia G; Fillmann, Gilberto

2015-07-15

Magellanic penguins have been reported as good biomonitors for several types of pollutants, including trace-elements. In this context, selenium (Se), total mercury, methylmercury, inorganic mercury (Hg(inorg)), cadmium (Cd) and lead (Pb), as well as metallothionein (MT) levels, were evaluated in the feathers, liver and kidney of juvenile Magellanic penguins found stranded along the coast of Southern Brazil. The highest concentrations of all trace-elements and methylmercury were found in internal organs. Concentrations of Cd and Se in feathers were extremely low in comparison with their concentrations in soft tissues. The results showed that both Se and MT are involved in the detoxification of trace-elements (Cd, Pb and Hg(inorg)) since statistically significant relationships were found in liver. Conversely, hepatic Se was shown to be the only detoxifying agent for methylmercury. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationship between sensitizer concentration and resist performance of chemically amplified extreme ultraviolet resists in sub-10 nm half-pitch resolution region

NASA Astrophysics Data System (ADS)

Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

2017-01-01

The development of lithography processes with sub-10 nm resolution is challenging. Stochastic phenomena such as line width roughness (LWR) are significant problems. In this study, the feasibility of sub-10 nm fabrication using chemically amplified extreme ultraviolet resists with photodecomposable quenchers was investigated from the viewpoint of the suppression of LWR. The relationship between sensitizer concentration (the sum of acid generator and photodecomposable quencher concentrations) and resist performance was clarified, using the simulation based on the sensitization and reaction mechanisms of chemically amplified resists. For the total sensitizer concentration of 0.5 nm-3 and the effective reaction radius for the deprotection of 0.1 nm, the reachable half-pitch while maintaining 10% critical dimension (CD) LWR was 11 nm. The reachable half-pitch was 7 nm for 20% CD LWR. The increase in the effective reaction radius is required to realize the sub-10 nm fabrication with 10% CD LWR.

Chemodynamics of heavy metals in long-term contaminated soils: metal speciation in soil solution.

PubMed

Kim, Kwon-Rae; Owens, Gary

2009-01-01

The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity (MWHC) after equilibration for 24 h. The free metal concentrations (Cd2+, CU2+, Pb2+, and Zn2+) in soil solution were determined using the Donnan membrane technique (DMT). Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd2+ (3%-52%) and Zn2+ (11%-72%) in soil solutions were generally higher than those of Cu2+ (0.2%-30%) and Pb2+ (0.6%-10%). Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients (K(p)) and dissolved organic carbon did not show any significant influence on K(p).

Involvement of selenoprotein P and GPx4 gene expression in cadmium-induced testicular pathophysiology in rat.

PubMed

Messaoudi, Imed; Banni, Mohamed; Saïd, Lamia; Saïd, Khaled; Kerkeni, Abdelhamid

2010-10-06

To investigate the effect of co-exposure to cadmium (Cd) and selenium (Se) on selenoprotein P (SelP) and phospholipid hydroperoxide glutathione peroxidase (GPx4) gene expression in testis and to evaluate their possible involvement in Cd-induced testicular pathophysiology, male rats received either tap water, Cd or Cd+Se in their drinking water for 5 weeks. Cd exposure caused a down-regulation of SelP and GPx4 gene expression and a significant decrease in plasma and testicular concentrations of Se. These changes were accompanied by decreased plasma testosterone level, sperm count and motility, GSH content, protein-bound sulfhydryl concentration (PSH), enzymatic activities of catalase (CAT) and glutathione peroxidase (GSH-Px) as well as by increased glutathione-S-transferase (GST) activity, lipid peroxidation (as malondialdehyde, MDA) and proteins carbonyls (PC). The decrease of testicular SelP and GPx4 gene expression under Cd influence was significantly restored in Cd+Se group. Co-treatment with Cd and Se also totally reversed the Cd-induced depletion of Se, decrease in plasma testosterone level and partially restored Cd-induced oxidative stress and decrease in sperm count and motility. Taken together, these data suggest that down-regulation of SelP and GPx4 gene expression induces plasma and testicular Se depletion leading, at least in part, to Cd-induced testicular pathophysiology. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

[Spatial variations of heavy metals in precipitation at Mount Taishan region].

PubMed

Wang, Yan; Liu, Xiao-Huan; Jin, Ling-Ren; Yue, Tai-Xing; Wang, De-Zhong; Wang, Wen-Xing

2007-11-01

Zn, Al, Mn, Fe, Pb, Cu, Ni, Cr, As, Cd in rain samples collected from two sites at Mount Taishan region were determined by ICP-MS, to evaluate the spatial variation characteristics of heavy metals in precipitation. Individual rain events were sampled for one whole year from Jan. to Dec. 2006. High concentrations of heavy metals were found at both sites, indicating serious heavy metal pollution. Zn was the most abundant element, accounting for 54% - 57% of the total metals concentrations. Its volume-weighted mean concentrations of precipitation at Mt-top and Mt-foot sites were 92.94 microg/L and 70.41 microg/L respectively. The following elements were Fe, Al and Mn and their concentrations were much higher than toxic heavy metals (As, Cd and Cd) except Pb (8.04 microg/L and 7.79 microg/L at two sites respectively). Comparison results between two sites suggested that heavy metal characteristics of precipitation at two sites were different, due to the influences of different ambient air conditions. Correlation analysis between two sites showed that Al, Mn, Fe, As, Cd, Pb influenced by air mass origin greatly, while Ni, Cu, Zn affected by other different factors.

Amino Acid Concentrations in HIV-Infected Youth Compared to Healthy Controls and Associations with CD4 Counts and Inflammation.

PubMed

Ziegler, Thomas R; Judd, Suzanne E; Ruff, Joshua H; McComsey, Grace A; Eckard, Allison Ross

2017-07-01

Amino acids play critical roles in metabolism, cell function, body composition and immunity, but little data on plasma amino acid concentrations in HIV are available. We evaluated plasma amino acid concentrations and associations with CD4 counts and inflammatory biomarkers in HIV-infected youth. HIV-infected subjects with a high (≥500 cells/mm 3 ) and low (<500 cells/mm 3 ) current CD4 + T cell counts were compared to one another and to a matched healthy control group. Plasma concentrations of 19 amino acids were determined with an amino acid analyzer. Plasma levels of interleukin-6, tumor necrosis factor receptor-I, and soluble vascular cellular adhesion molecule-I were also measured. Seventy-nine HIV-infected subjects (40 and 39 with high and low CD4 + T cell counts, respectively) and 40 controls were included. There were no differences in amino acid concentrations between HIV-infected subjects with high or low CD4 + T cell counts. When combined, the HIV-infected group exhibited significantly lower median plasma concentrations compared to controls for total, essential, branched-chain and sulfur amino acids, as well as for 12 individual amino acids. Glutamate was the only amino acid that was higher in the HIV-infected group. There were no significant correlations between amino acid endpoints and inflammatory biomarkers for either HIV-infected group or controls. Plasma amino acid concentrations were lower in HIV-infected youth compared to healthy controls, regardless of immune status, while glutamate concentrations were elevated. These findings can inform future interventional studies designed to improve metabolic and clinical parameters influenced by amino acid nutriture.

Phytoextraction of Cadmium and Zinc By Sedum plumbizincicola Using Different Nitrogen Fertilizers, a Nitrification Inhibitor and a Urease Inhibitor.

PubMed

Arnamwong, Suteera; Wu, Longhua; Hu, Pengjie; Yuan, Cheng; Thiravetyan, Paitip; Luo, Yongming; Christie, Peter

2015-01-01

Cadmium (Cd) and zinc (Zn) phytoavailability and their phytoextraction by Sedum plumbizincicola using different nitrogen fertilizers, nitrification inhibitor (dicyandiamide, DCD) and urease inhibitor (N-(n-Butyl) thiophosphoric triamide, NBPT) were investigated in pot experiments where the soil was contaminated with 0.99 mg kg(-1) of Cd and 241 mg kg(-1) Zn. The soil solution pH varied between 7.30 and 8.25 during plant growth which was little affected by the type of N fertilizer. The (NH4)2SO4+DCD treatment produced higher NH4+-N concentrations in soil solution than the (NH4)2SO4 and NaNO3 treatment which indicated that DCD addition inhibited the nitrification process. Shoot Cd and Zn concentrations across all treatments showed ranges of 52.9-88.3 and 2691-4276 mg kg(-1), respectively. The (NH4)2SO4+DCD treatment produced slightly higher but not significant Cd and Zn concentrations in the xylem sap than the NaNO3 treatment. Plant shoots grown with NaNO3 had higher Cd concentrations than (NH4)2SO4+DCD treatment at 24.0 and 15.4 mg kg(-1), respectively. N fertilizer application had no significant effect on shoot dry biomass. Total Cd uptake in the urea+DCD treatment was higher than in the control, urea+NBPT, urea+NBPT+DCD, or urea treatments, by about 17.5, 23.3, 10.7, and 25.1%, respectively.

Chemical speciation of cadmium: An approach to evaluate plant-available cadmium in Ecuadorian soils under cacao production.

PubMed

Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R S; Li, Y C; Baligar, V C

2016-05-01

Elevated concentration of cadmium (Cd) in cacao beans has raised serious concerns about the chocolate consumption on human health. Accumulation of Cd in cacao bean in southern Ecuador has been related to soil contamination. In this study, soil fractionation approach was used to identify available Cd pools in the soils and to correlate these Cd pools with bean Cd concentration and soil test indexes. The distribution of soil Cd fractions decreased in the order: oxidizable > acid-soluble > residual > reducible > water-soluble (+exchangeable). Oxidizable and acid-soluble fractions accounted for 59 and 68% of the total recoverable Cd for the 0-5 and 5-15 cm soil depth, respectively. Acid-soluble fraction was closely related to bean-Cd, with correlation coefficients (r) of 0.70 and 0.81 (P < 0.01) for the 0-5 and 5-15 cm soil depth, respectively. Acid-soluble Cd was significantly correlated with 0.01 M HCl- (r = 0.99, P < 0.01) or Mehlich 3- extractable Cd (r = 0.97, P < 0.01). These results indicate that acid-soluble Cd fraction is an important part of available Cd pool. Since approximately 60% of Cd in the cacao-growing soils is related to the acid-soluble fraction and bound to organic matter, remediation of the contaminated soils should consider to the dynamics of soil pH and organic matter content. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical fractionation of heavy metals in urban soils of Guangzhou, China.

PubMed

Lu, Ying; Zhu, Feng; Chen, Jie; Gan, Haihua; Guo, Yanbiao

2007-11-01

Knowledge of the total concentration of heavy metals is not enough to fully assess the environmental impact of urban soils. For this reason, the determination of metal speciation is important to evaluate their environment and the mobilization capacity. Sequential extraction technique proposed by the former European Community Bureau of Reference (BCR) was used to speciate Cd, Cu, Fe, Mn, Ni, Pb, and Zn in urban soils from Guangzhou into four operationally defined fractions: HOAc extractable, reducible, oxidizable, and residual. The Cu, Fe, Ni, and Zn were predominantly located in the residual fraction, Pb in the reducible fraction, and Cd and Mn within the HOAc extractable fraction. The order of Cd in each fraction was generally HOAc extractable > reducible > residual > oxidizable; Cu and Fe were residual > reducible > oxidizable > HOAc extractable; Mn was HOAc extractable > residual > reducible > oxidizable; Ni and Zn were residual > reducible > HOAc extractable > oxidizable; and Pb was reducible > residual > oxidizable > HOAc extractable. Cadmium was identified as being the most mobile of the elements, followed by Mn, Zn, Ni, Cu, Pb and Fe. Iron-Mn oxides can play an important role in binding Cd, Cu, Ni, Pb, and Zn and in decreasing their proportion associated with the residual fraction in the soils. With total concentrations of Cd, Cu, Ni, Pb, Zn, and Mn increase, these metals more easily release and may produce more negative effects on the urban environment.

Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda.

PubMed

Nabulo, Grace; Oryem-Origa, Hannington; Diamond, Miriam

2006-05-01

The relationship between traffic density and trace metal concentrations in roadside soils, surface films, and a selected vegetable weed, Amaranthus dubius Mart. Ex Thell., was determined in 11 farming sites along major highways around Kampala City in Uganda. Surface soil, atmospherically deposited surface films on windows, and leaves of Amaranthus dubius were sampled at known distances from the roads and analyzed for lead (Pb), zinc (Zn), and cadmium (Cd) using flame atomic absorption spectrophotometry. Atmospherically deposited trace metal particulates were sampled using window glass as an inert, passive collector. Total trace metal concentrations in soils ranged from 30.0+/-2.3 to 64.6+/-11.7 mg/kg Pb, 78.4+/-18.4 to 265.6+/-63.2 mg/kg Zn, and 0.8+/-0.13 to 1.40+/-0.16 mg/kg Cd. Total trace metal levels in soil decreased rapidly with distance from the road. Total Pb decreased with distance up to 30 m from the road, where it reached a background soil concentration of 28 mg/kg dry weight. The study found background values of 50 and 1.4 mg/kg for Zn and Cd in roadside soils, respectively. Similarly, Pb concentration in Amaranthus dubius leaves decreased with increasing distance from the road edge. The dominant pathway for Pb contamination was from atmospheric deposition, which was consistent with Pb concentrations in surface films. The mean Pb concentrations in leaves of roadside crops were higher than those in their respective roots, with the highest leaf-to-root ratio observed in the Brassica oleraceae acephala group. The lowest Pb and Zn concentrations were found in the fruit compared to the leaves of the same crops. Leaves of roadside vegetables were therefore considered a potential source of heavy metal contamination to farmers and consumers in urban areas. It is recommended that leafy vegetables should be grown 30 m from roads in high-traffic, urban areas.

Assessment of lead, cadmium, and zinc contamination of roadside soils, surface films, and vegetables in Kampala City, Uganda

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nabulo, Grace; Oryem-Origa, Hannington; Diamond, Miriam

2006-05-15

The relationship between traffic density and trace metal concentrations in roadside soils, surface films, and a selected vegetable weed, Amaranthus dubius Mart. Ex Thell., was determined in 11 farming sites along major highways around Kampala City in Uganda. Surface soil, atmospherically deposited surface films on windows, and leaves of Amaranthus dubius were sampled at known distances from the roads and analyzed for lead (Pb), zinc (Zn), and cadmium (Cd) using flame atomic absorption spectrophotometry. Atmospherically deposited trace metal particulates were sampled using window glass as an inert, passive collector. Total trace metal concentrations in soils ranged from 30.0{+-}2.3 to 64.6{+-}11.7more » mg/kg Pb, 78.4{+-}18.4 to 265.6{+-}63.2 mg/kg Zn, and 0.8{+-}0.13 to 1.40{+-}0.16 mg/kg Cd. Total trace metal levels in soil decreased rapidly with distance from the road. Total Pb decreased with distance up to 30 m from the road, where it reached a background soil concentration of 28 mg/kg dry weight. The study found background values of 50 and 1.4 mg/kg for Zn and Cd in roadside soils, respectively. Similarly, Pb concentration in Amaranthus dubius leaves decreased with increasing distance from the road edge. The dominant pathway for Pb contamination was from atmospheric deposition, which was consistent with Pb concentrations in surface films. The mean Pb concentrations in leaves of roadside crops were higher than those in their respective roots, with the highest leaf-to-root ratio observed in the Brassica oleraceae acephala group. The lowest Pb and Zn concentrations were found in the fruit compared to the leaves of the same crops. Leaves of roadside vegetables were therefore considered a potential source of heavy metal contamination to farmers and consumers in urban areas. It is recommended that leafy vegetables should be grown 30 m from roads in high-traffic, urban areas.« less

Effects of soil properties on the transfer of cadmium from soil to wheat in the Yangtze River delta region, China--a typical industry-agriculture transition area.

PubMed

Wang, Cheng; Ji, Junfeng; Yang, Zhongfang; Chen, Lingxiao; Browne, Patrick; Yu, Ruilian

2012-08-01

In order to identify the effects of soil properties on the transfer of Cd from soil to wheat under actual field conditions, 126 pairs of topsoil and wheat samples were collected from the Yangtze River delta region, China. Relevant parameters (Cd, Ca, Mg, Fe, Mn, Zn, N, P, K, S, pH, total organic carbon, and speciation of soil Cd) in soil and wheat tissues were analyzed, and the results were treated by statistical methods. Soil samples (19.8%) and 14.3% of the wheat grain samples exceeded the relevant maximum permissible Cd concentrations in China for agricultural soil and wheat grain, respectively. The major speciations of Cd in soil were exchangeable, bound to carbonates and fulvic and humic acid fraction, and they were readily affected by soil pH, total Ca, Mg, S and P, DTPA-Fe, Ex-Ca, and Ex-Mg. Cadmium showed a strong correlation with Fe, S, and P present in the grain and the soil, whereas there was no significant correlation in the straw or root. Generally, soil pH, Ca, Mg, Mn, P, and slowly available K restricted Cd transfer from soil to wheat, whereas soil S, N, Zn, DTPA-Fe, and total organic carbon enhance Cd uptake by wheat.

Metal accumulation strategies in plants spontaneously inhabiting Zn-Pb waste deposits.

PubMed

Wójcik, Małgorzata; Sugier, Piotr; Siebielec, Grzegorz

2014-07-15

Metal (Zn, Pb, Cd, Cu, Ni, Cr) accumulation in shoots of 38 plant species spontaneously colonizing three Zn-Pb waste deposits in southern Poland was studied in order to find out if the age of the waste (30-130 years) or its type (slag or flotation residues) influence metal content in plants and to identify species potentially suitable for biomonitoring and phytoremediation. The total metal concentrations in the waste upper layers ranged from 7300 to 171,790 mg kg(-1) for Zn, from 1390 to 22,265 mg kg(-1) for Pb, and from 66 to 1,464 mg kg(-1) for Cd, whereas CaCl2-extracted fractions accounted for 0.034-0.11 %, 0.005-0.03 %, and 0.28-0.62 % of total Zn, Pb and Cd concentrations, respectively. The concentrations of Cu, Ni, and Cr in substrates and in plants were low and ranged within the background values. Metal accumulation in plant shoots was poorly correlated with both total and CaCl2-extracted forms of metals in the substrate and was highly variable among species and also specimens of the same species. The highest mean concentrations of Zn, Pb and Cd were found in Anthyllis vulneraria L. (901.5 mg kg(-1)), Echium vulgare L. (116.92 mg kg(-1)), and Hieracium piloselloides Vill. (26.86 mg kg(-1)), respectively. Besides Reseda lutea L., no species appeared to be a good indicator of polymetallic environment pollution based on chemical analysis of shoots; however, metal accumulation in the whole plant communities of a particular contaminated area might be an accurate tool for assessment of metal transfer to vegetation irrespective of the type or age of the waste. All the species studied developed a metal exclusion strategy, thus exhibiting potential for phytostabilization of metalliferous wastelands. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of binary mixtures of zinc, copper, cadmium, and nickel on the growth of the freshwater diatom Navicula pelliculosa and comparison with mixture toxicity model predictions.

PubMed

Nagai, Takashi; De Schamphelaere, Karel A C

2016-11-01

The authors investigated the effect of binary mixtures of zinc (Zn), copper (Cu), cadmium (Cd), and nickel (Ni) on the growth of a freshwater diatom, Navicula pelliculosa. A 7 × 7 full factorial experimental design (49 combinations in total) was used to test each binary metal mixture. A 3-d fluorescence microplate toxicity assay was used to test each combination. Mixture effects were predicted by concentration addition and independent action models based on a single-metal concentration-response relationship between the relative growth rate and the calculated free metal ion activity. Although the concentration addition model predicted the observed mixture toxicity significantly better than the independent action model for the Zn-Cu mixture, the independent action model predicted the observed mixture toxicity significantly better than the concentration addition model for the Cd-Zn, Cd-Ni, and Cd-Cu mixtures. For the Zn-Ni and Cu-Ni mixtures, it was unclear which of the 2 models was better. Statistical analysis concerning antagonistic/synergistic interactions showed that the concentration addition model is generally conservative (with the Zn-Ni mixture being the sole exception), indicating that the concentration addition model would be useful as a method for a conservative first-tier screening-level risk analysis of metal mixtures. Environ Toxicol Chem 2016;35:2765-2773. © 2016 SETAC. © 2016 SETAC.

Graded versus Intermittent Exercise Effects on Lymphocytes in Chronic Fatigue Syndrome.

PubMed

Broadbent, Suzanne; Coutts, Rosanne

2016-09-01

There is increasing evidence of immune system dysfunction in chronic fatigue syndrome (CFS), but little is known of the regular exercise effects on immune cell parameters. This pilot study investigated the effects of graded and intermittent exercise on CD4 lymphocyte subset counts and activation compared with usual care. Twenty-four CFS patients (50.2 ± 10 yr) were randomized to graded exercise (GE), intermittent exercise (IE), or usual care (UC) groups; 18 sedentary non-CFS participants (50.6 ± 10 yr) were controls (CTL) for blood and immunological comparisons. Outcome measures were pre- and postintervention flow cytometric analyses of circulating lymphocyte subset cell counts; expression of CD3, CD4, CD25, and CD134; full blood counts; and V˙O2peak. Preintervention, CD3 cell counts, and expression of CD4, CD25, CD134, and CD4CD25CD134 were significantly lower in GE, IE, and UC compared with CTL (P < 0.05). Total lymphocyte concentration was significantly lower in GE and IE groups compared with CTL. There were significant postintervention increases in i) expression of CD4 and CD4CD25CD134 for GE and IE, but CD25 and CD134 for IE only; ii) circulating counts of CD3 and CD4 for GE, and CD3, CD4, CD8, CD3CD4CD8, CD3CD16CD56, CD19, and CD45 for IE; iii) neutrophil concentration for GE; and iv) V˙O2peak and elapsed test time for IE and GE, V˙Epeak for IE. Twelve weeks of GE and IE training significantly improved CD4 lymphocyte activation and aerobic capacity without exacerbating CFS symptoms. IE may be a more effective exercise modality with regard to enhanced CD4 activation in CFS patients.

[Stem cell mobilization after coronary artery bypass grafting].

PubMed

Gaspardone, Achille; De Fabritiis, Paolo; Scaffa, Raffaele; Nardi, Paolo; Palombi, Francesca; Versaci, Francesco; Chiariello, Luigi

2004-01-01

Recently, the role of stem cells as a potential therapeutic tool for ischemic heart disease has been evaluated by a number of experimental and clinical studies. Although preliminary clinical data appear to be promising, the precise pathophysiological role of stem cell mobilization during acute myocardial ischemia remains uncertain. The present study was aimed at assessing factors affecting stem cell mobilization after coronary artery bypass grafting used as a clinical model of controlled myocardial ischemia. Eighteen patients (16 men, 2 women, mean age 66 +/- 8 years) with three-vessel coronary artery disease undergoing coronary artery bypass grafting were included in the study; 24 age- and sex-matched healthy subjects served as controls. On admission, 10 patients had stable angina and 8 had unstable angina. Clinical history and instrumental evidence of previous myocardial infarction were present in 11 patients. Venous peripheral blood was sampled at baseline and 6, 24, 48 and 72 hours after coronary surgery. Duration of cardiac arrest and extracorporeal circulation were recorded as well as the release of total creatine kinase (CK), CK-MB, troponin I and C-reactive protein. CD34+ stem cells were analyzed by flow cytometry according to published methods. In patients with ischemic heart disease the peripheral concentration of CD34+ cells was higher than that of control subjects (0.202 +/- 0.30 vs 0.068 +/- 0.059%, p = 0.03). However, patients with stable and unstable angina had similar concentration of CD34+ cells (0.171 +/- 0.33 vs 0.241 +/- 0.275%, p = 0.63) as well as patients with and without previous myocardial infarction (0.134 +/- 0.19 vs 0.245 +/- 0.352%, p = 0.4). Coronary artery bypass grafting caused a non-significant increase in concentration of CD34+ cells at 24 hours which was similar in patients with stable and unstable angina. Finally, no significant correlation was found between peripheral concentration of CD34+ cells and aortic clamping and extracorporeal circulation duration, peak release of total CK, CK-MB, troponin I and C-reactive protein. Peripheral concentration of CD34+ stem cells is higher in patients with ischemic heart disease than in healthy controls but it is similar in patients with stable and unstable coronary syndromes. Peripheral mobilization of CD34+ cells is not correlated with the duration and severity of ischemic insult induced by surgical cardiac arrest. These preliminary findings suggest that CD34+ cell mobilization may be modulated more by tonically active than phasic factors.

Surface complexation modeling of proton and Cd adsorption onto an algal cell wall.

PubMed

Kaulbach, Emily S; Szymanowski, Jennifer E S; Fein, Jeremy B

2005-06-01

This study quantifies Cd adsorption onto the cell wall of the algal species Pseudokirchneriella subcapitata by applying a surface complexation approach to model the observed adsorption behavior. We use potentiometric titrations to determine deprotonation constants and site concentrations for the functional groups on the algal cell wall. Adsorption and desorption kinetics experiments illustrate that adsorption of Cd onto the cell wall is rapid and reversible, except under low pH conditions. Adsorption experiments conducted as a function of pH and total Cd concentration yield the stoichiometry and site-specific stability constants for the important Cd-algal surface complexes. We model the acid/base properties of the algal cell wall by invoking four discrete surface functional group types, with pKa values of 3.9 +/- 0.3, 5.4 +/- 0.1, 7.6 +/- 0.3, and 9.6 +/- 0.4. The results of the Cd adsorption experiments indicate that the first, third, and fourth sites contribute to Cd adsorption under the experimental conditions, with calculated log stability constant values of 4.1 +/- 0.5, 5.4 +/- 0.5, and 6.1 +/- 0.4, respectively. Our results suggest that the stabilities of the Cd-surface complexes are high enough for algal adsorption to affect the fate and transport of Cd under some conditions and that on a per gram basis, algae and bacteria exhibit broadly similar extents of Cd adsorption.

Alleviation of cadmium toxicity in Lemna minor by exogenous salicylic acid.

PubMed

Lu, Qianqian; Zhang, Tingting; Zhang, Wei; Su, Chunlei; Yang, Yaru; Hu, Dan; Xu, Qinsong

2018-01-01

Cadmium (Cd) is a significant environmental pollutant in the aquatic environment. Salicylic acid (SA) is a ubiquitous phenolic compound. The goal of this study was to assess the morphological, physiological and biochemical changes in duckweed (L. minor) upon exposure to 10μM CdCl 2 , 10μM CdCl 2 plus 50μM SA, or 50μM SA for 7 days. Reversing the effects of Cd, SA decreased Cd accumulation in plants, improved accumulation of minerals (Ca, Mg, Fe, B, Mo) absorption, increased endogenous SA concentration, and phenylalanine ammonialyase (PAL) activity. Chlorosis-associated symptoms, the reduction in chlorophyll content, and the overproduction of reactive oxygen species induced by Cd exposure were largely reversed by SA. SA significantly decreased the toxic effects of Cd on the activities of the superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione reductase in the fronds of L. minor. Furthermore, SA reversed the detrimental effects of Cd on total ascorbate, glutathione, the ascorbic acid/oxidized dehydroascorbate and glutathione/glutathione disulphide ratios, lipid peroxidation, malondialdehyde concentration, lipoxygenase activity, and the accumulation of proline. SA induced the up-regulation of heat shock proteins (Hsp70) and attenuated the adverse effects of Cd on cell viability. These results suggest that SA confers tolerance to Cd stress in L. minor through different mechanisms. Copyright © 2017 Elsevier Inc. All rights reserved.

A Limited Survey of Heavy Metal Concentrations in Fresh and Frozen Cuttlefish Ink and Mantle Used As Food.

PubMed

Conficoni, Daniele; Alberghini, Leonardo; Bissacco, Elisa; Contiero, Barbara; Giaccone, Valerio

2018-02-01

Cuttlefish ink is consumed as a delicacy worldwide. The current study is the first assessment of heavy metal concentrations in cuttlefish ink versus mantle under different storage methods. A total of 212 samples (64 of fresh mantle, 42 of frozen mantle, 64 of fresh ink, and 42 of frozen ink) were analyzed for the detection of the following heavy metals: arsenic (As), chromium (Cr), iron (Fe), lead (Pb), mercury (Hg), and cadmium (Cd). The median As concentrations were 12.9 mg/kg for fresh mantle, 8.63 mg/kg for frozen mantle, 10.8 mg/kg for frozen ink, and 0.41 mg/kg for fresh ink. The median Cr concentrations were 0.06 mg/kg for fresh mantle and frozen ink, 0.03 mg/kg for frozen mantle, and below the limit of quantification (LOQ) for fresh ink. The median Fe concentrations were 4.08 mg/kg for frozen ink, 1.51 mg/kg for fresh mantle, 0.73 mg/kg for frozen mantle, and below the LOQ for fresh ink. The median Pb concentrations of almost all samples were below the LOQ; only two frozen ink, one fresh ink, one frozen mantle, and one fresh mantle sample exceeded the limit stipulated by the European Union. The Hg concentrations were statistically similar among the four categories of samples; the median Hg concentrations were below the LOQ, and the maximum concentrations were found in frozen ink, at 1.62 mg/kg. The median Cd concentrations were 0.69 mg/kg for frozen ink and 0.11 mg/kg for frozen mantle, fresh mantle and fresh ink concentrations were below the LOQ, and in 11.3% of the tested samples, Cd concentrations were higher than the European Union limit. The probability of samples having a Cd concentration above the legal limit was 35.75 times higher in frozen than in fresh products. Fresh ink had significantly lower concentrations of As, Cr, Fe, and Cd, but the concentrations of Hg and Pb were not significantly different from those of other products. Frozen ink had significantly higher concentrations of Cd, Cr, and Fe, but concentrations of As were lower than those in fresh mantle, pointing out a possible role for the freezing process and for different fishing zones as risk factors for heavy metal contamination.

Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: inter-population variability and a generalised predictive model.

PubMed

Kalman, J; Smith, B D; Riba, I; Blasco, J; Rainbow, P S

2010-06-01

Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised values of metal-specific parameters were chosen to generate a generalised model to be extended to N. diversicolor populations across a wide geographical range from western Europe to North Africa. According to the assumptions of this model, predicted steady state concentrations of Cd and Zn in N. diversicolor were overestimated, those of Ag underestimated, but still comparable to independent field measurements. We conclude that species-specific physiological metal bioaccumulation parameters are relatively constant over large geographical distances, and a single generalised biodynamic model does have potential to predict accumulated Ag, Cd and Zn concentrations in this polychaete from a single sediment metal concentration.

Variation and significance of secretory immunoglobulin A, interleukin 6 and dendritic cells in oral cancer.

PubMed

Zhang, Suxin; Zhang, Xin; Yin, Ke; Li, Tianke; Bao, Yang; Chen, Zhong

2017-04-01

The present study aimed to determine changes in the concentration of secretory immunoglobulin A (SIgA) and interleukin 6 (IL-6) in the saliva of patients with oral cancer, to evaluate the abnormal expression of cluster of differentiation (CD) 1a, CD83, CD80 and CD86 on dendritic cells (DCs) of oral cancer tissues and to discuss the interaction between SIgA, IL-6 and DCs in oral cancer. A total of 40 patients between 27 and 70 years of age, median age 52 years, with primary oral cancer were enrolled in the present study, and a group of 20 healthy male and female volunteers was used as the control group. The concentration of SIgA and IL-6 in the saliva of the preoperative patients was determined by ELISA. The expression levels of CD1a, CD83, CD80 and CD86 were detected by immunohistochemistry and flow cytometry, which was performed on histopathological sections from paraffin-embedded tumor and corresponding adjacent control tissues. The specimens were assessed using the semi-quantitative immunoreactive score (IRS). The concentration of SIgA in the saliva from patients with oral cancer decreased, whereas the IL-6 level significantly increased compared with the control subjects (P<0.05). In addition, the decrease of SIgA level and increase of IL-6 level exhibited a negative correlation (r=-0.543, P<0.05). According to the IRS score, the expression levels of CD1a, CD83, CD80 and CD86 in the cancer tissue were lower than the expression levels of the control group (P<0.05). Furthermore, the expression of CD80 and CD86 exhibited no correlation with histological grade or pathological type (P>0.05), but exhibited a negative correlation with clinical stage and lymph node metastasis (P<0.05). The concentration of SIgA and IL-6 in saliva may be used as an auxiliary diagnostic indicator for oral cancer. The detection of CD80 and CD86 expressed on DCs in oral cancer tissue may be useful for the diagnosis and evaluation of the prognosis of tumors. The present study hypothesized that the use of SIgA vaccines or IL-6 inhibitors may be useful for reversing the immune deficiency associated with DCs in oral cancer.

Accumulation of cadmium, zinc, and copper by Helianthus annuus L.: impact on plant growth and uptake of nutritional elements.

PubMed

Rivelli, Anna Rita; De Maria, Susanna; Puschenreiter, Markus; Gherbin, Piergiorgio

2012-04-01

We investigated the effects on physiological response, trace elements and nutrients accumulation of sunflower plants grown in soil contaminated with: 5 mg kg(-1) of Cd; 5 and 300 mg kg(-1) of Cd and Zn, respectively; 5, 300, and 400 mg kg(-1) of Cd, Zn, and Cu, respectively. Contaminants applied did not produce large effects on growth, except in Cd-Zn-Cu treatment in which leaf area and total dry matter were reduced, by 15%. The contamination with Cd alone did not affect neither growth nor physiological parameters, despite considerable amounts of Cd accumulated in roots and older leaves, with a high bioconcentration factor from soil to plant. By adding Zn and then Cu to Cd in soil, significant were the toxic effects on chlorophyll content and water relations due to greater accumulation of trace elements in tissues, with imbalances in nutrients uptake. Highly significant was the interaction between shoot elements concentration (Cd, Zn, Cu, Fe, Mg, K, Ca) and treatments. Heavy metals concentrations in roots always exceeded those in stem and leaves, with a lower translocation from roots to shoots, suggesting a strategy of sunflower to compartmentalise the potentially toxic elements in physiologically less active parts in order to preserve younger tissues.

Effects of warming on uptake and translocation of cadmium (Cd) and copper (Cu) in a contaminated soil-rice system under Free Air Temperature Increase (FATI).

PubMed

Ge, Li-Qiang; Cang, Long; Liu, Hui; Zhou, Dong-Mei

2016-07-01

Global warming has received growing attentions about its potential threats to human in recent, however little is known about its effects on transfer of heavy metals in agro-ecosystem, especially for Cd in rice. Pot experiments were conducted to evaluate Cd/Cu translocation in a contaminated soil-rice system under Free Air Temperature Increase (FATI). The results showed that warming gradually decreased soil porewater pH and increased water-soluble Cd/Cu concentration, reduced formation of iron plaque on root surface, and thus significantly increased total uptake of Cd/Cu by rice. Subsequently, warming significantly promoted Cd translocation from root to shoot, and increased Cd distribution percentage in shoot, while Cu was not significantly affected. Enhanced Cd uptake and translocation synergistically resulted in higher rice grain contamination with increasing concentration from 0.27 to 0.65 and 0.14-0.40 mg kg(-1) for Indica and Japonica rice, respectively. However increase of Cu in brown grain was only attributed to its uptake enhancement under warming. Our study provides a new understanding about the food production insecurity of heavy metal contaminated soil under the future global warming. Copyright © 2016. Published by Elsevier Ltd.

Improvement of phytoremediation of an aged petroleum hydrocarbon-contaminated soil by Rhodococcus erythropolis CD 106 strain.

PubMed

Płociniczak, Tomasz; Fic, Ewa; Pacwa-Płociniczak, Magdalena; Pawlik, Małgorzata; Piotrowska-Seget, Zofia

2017-07-03

The aim of this study was to assess the impact of soil inoculation with the Rhodococcus erythropolis CD 106 strain on the effectiveness of the phytoremediation of an aged hydrocarbon-contaminated [approx. 1% total petroleum hydrocarbon (TPH)] soil using ryegrass (Lolium perenne). The introduction of CD 106 into the soil significantly increased the biomass of ryegrass and the removal of hydrocarbons in planted soil. The fresh weight of the shoots and roots of plants inoculated with CD 106 increased by 49% and 30%, respectively. After 210 days of the experiment, the concentration of TPH was reduced by 31.2%, whereas in the planted, non-inoculated soil, it was reduced by 16.8%. By contrast, the concentration of petroleum hydrocarbon decreased by 18.7% in non-planted soil bioaugmented with the CD 106 strain. The rifampicin-resistant CD 106 strain survived after inoculation into soil and was detected in the soil during the entire experimental period, but the number of CD 106 cells decreased constantly during the enhanced phytoremediation and bioaugmentation experiments. The plant growth-promoting and hydrocarbon-degrading properties of CD 106, which are connected with its long-term survival and limited impact on autochthonous microflora, make this strain a good candidate for improving the phytoremediation efficiency of soil contaminated with hydrocarbons.

Arsenic, cadmium, and manganese levels in shellfish from Map Ta Phut, an industrial area in Thailand, and the potential toxic effects on human cells.

PubMed

Rangkadilok, Nuchanart; Siripriwon, Pantaree; Nookabkaew, Sumontha; Suriyo, Tawit; Satayavivad, Jutamaad

2015-01-01

Map Ta Phut Industrial Estate is a major industrial area in Thailand for both petrochemical and heavy industries. The release of hazardous wastes and other pollutants from these industries increases the potential for contamination in foods in the surrounding area, especially farmed shellfish. This study determined the arsenic (As), cadmium (Cd), and manganese (Mn) concentrations in the edible flesh of farmed shellfish, including Perna viridis, Meretrix meretrix, and Scapharca inaequivalvis, around the Map Ta Phut area using inductively coupled plasma mass spectrometry. The results showed that shellfish samples contained high levels of total As [1.84-6.42 mg kg(-1) wet weight (ww)]. High Mn concentrations were found in P. viridis and M. meretrix, whereas S. inaequivalis contained the highest Cd. Arsenobetaine (AsB) was found to be the major As species in shellfish (>45% of total As). The in vitro cytotoxicity of these elements was evaluated using human cancer cells (T47D, A549, and Jurkat cells). An observed decrease in cell viability in T47D and Jurkat cells was mainly caused by exposure to inorganic As (iAs) or Mn but not to AsB or Cd. The combined elements (AsB+Mn+Cd) at concentrations predicted to result from the estimated daily intake of shellfish flesh by the local people showed significant cytotoxicity in T47D and Jurkat cells.

Yield, quality, and concentration of seven heavy metals in cabbage and broccoli grown in sewage sludge and chicken manure amended soil.

PubMed

Antonious, George F; Kochhar, Tejinder S; Coolong, Timothy

2012-01-01

The mobility of heavy metals from soil into the food chain and their subsequent bioaccumulation has increased the attention they receive as major environmental pollutants. The objectives of this investigation were to: i) study the impact of mixing native agricultural soil with municipal sewage sludge (SS) or chicken manure (CM) on yield and quality of cabbage and broccoli, ii) quantify the concentration of seven heavy metals (Cd, Cr, Mo, Cu, Zn, Pb, and Ni) in soil amended with SS or CM, and iii) determine bioavailability of heavy metals to cabbage leaves and broccoli heads at harvest. Analysis of the two soil amendments used in this investigation indicated that Cr, Ni, Cu, Zn, Mo, Cd, Pb, and organic matter content were significantly greater (P < 0.05) in premixed sewage sludge than premixed chicken manure. Total cabbage and broccoli yields obtained from SS and CM mixed soil were both greater than those obtained from no-mulch (bare) soil. Concentration of Ni in cabbage leaves of plants grown in soil amended with CM was low compared to plants grown in no-mulch soil. No significant differences were found in Cd and Pb accumulation between cabbage and broccoli. Concentrations of Ni, Cu, Zn, and Mo were greater in broccoli than cabbage. Total metals and plant available metals were also determined in the native and amended soils. Results indicated that the concentration of heavy metals in soils did not necessary reflect metals available to plants. Regardless of soil amendments, the overall bioaccumulation factor (BAF) of seven heavy metals in cabbage leaves and broccoli heads revealed that cabbage and broccoli were poor accumulators of Cr, Ni, Cu, Cd, and Pb (BAF <1), while BAF values were >1 for Zn and Mo. Elevated Ni and Mo bioaccumulation factor (BAF >1) of cabbage grown in chicken manure mixed soil is a characteristic that would be less favorable when cabbage is grown on sites having high concentrations of these two metals.

Heavy metal contamination of arable soil and corn plant in the vicinity of a zinc smelting factory and stabilization by liming.

PubMed

Hong, Chang Oh; Gutierrez, Jessie; Yun, Sung Wook; Lee, Yong Bok; Yu, Chan; Kim, Pil Joo

2009-02-01

The heavy metal contamination in soils and cultivated corn plants affected by zinc smelting activities in the vicinity of a zinc smelting factory in Korea was studied. Soils and corn plants were sampled at the harvesting stage and analyzed for cadmium (Cd) and zinc (Zn) concentration, as well as Cd and Zn fraction and other chemical properties of soils. Cd and Zn were highly accumulated in the surface soils (0-20 cm), at levels higher than the Korean warning criteria (Cd, 1.5; Zn, 300 mg kg(-1)), with corresponding mean values of 1.7 and 407 mg kg(-1), respectively, but these metals decreased significantly with increasing soil depth and distance from the factory, implying that contaminants may come from the factory through aerosol dynamics (Hong et al., Kor J Environ Agr 26(3):204-209, 2007a; Environ Contam Toxicol 52:496-502, 2007b) and not from geological sources. The leaf part had higher Cd and Zn concentrations, with values of 9.5 and 1733 mg kg(-1), compared to the stem (1.6 and 547 mg kg(-1)) and grain (0.18 and 61 mg kg(-1)) parts, respectively. Cd and Zn were higher in the oxidizable fraction, at 38.5% and 46.9% of the total Cd (2.6 mg kg(-1)) and Zn (407 mg kg(-1)), but the exchangeable + acidic fraction of Cd and Zn as the bioavailable phases was low, 0.2 and 50 mg kg(-1), respectively. To study the reduction of plant Cd and Zn uptake by liming, radish (Raphanus sativa L.) was cultivated in one representative field among the sites investigated, and Ca(OH)(2) was applied at rates of 0, 2, 4, and 8 mg ha(-1). Plant Cd and Zn concentrations and NH(4)OAc extractable Cd and Zn concentrations of soil decreased significantly with increasing Ca(OH)(2) rate, since it markedly increases the cation exchange capacity of soil induced by increased pH. As a result, liming in this kind of soil could be an effective countermeasure in reducing the phytoextractability of Cd and Zn.

Soil contamination assessment for Pb, Zn and Cd in a slag disposal area using the integration of geochemical and microbiological data.

PubMed

Kasemodel, Mariana Consiglio; Lima, Jacqueline Zanin; Sakamoto, Isabel Kimiko; Varesche, Maria Bernadete Amancio; Trofino, Julio Cesar; Rodrigues, Valéria Guimarães Silvestre

2016-12-01

Improper disposal of mining waste is still considered a global problem, and further details on the contamination by potentially toxic metals are required for a proper assessment. In this context, it is important to have a combined view of the chemical and biological changes in the mining dump area. Thus, the objective of this study was to evaluate the Pb, Zn and Cd contamination in a slag disposal area using the integration of geochemical and microbiological data. Analyses of soil organic matter (SOM), pH, Eh, pseudo-total concentration of metals, sequential extraction and microbial community by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were conducted. Metal availability was evaluated based on the geoaccumulation index (I geo ), ecological risk ([Formula: see text]), Risk Assessment Code (RAC) and experimental data, and different reference values were tested to assist in the interpretation of the indices. The soil pH was slightly acidic to neutral, the Eh values indicated oxidized conditions and the average SOM content varied from 12.10 to 53.60 g kg -1 . The average pseudo-total concentrations of metals were in the order of Zn > Pb > Cd. Pb and Zn were mainly bound to the residual fraction and Fe-Mn oxides, and a significant proportion of Cd was bound to the exchangeable and carbonate fractions. The topsoil (0-20 cm) is highly contaminated (I geo ) with Cd and has a very high potential ecological risk ([Formula: see text]). Higher bacterial diversity was mainly associated with higher metal concentrations. It is concluded that the integration of geochemical and microbiological data can provide an appropriate evaluation of mining waste-contaminated areas.

Cd-induced production of glomalin by arbuscular mycorrhizal fungus (Rhizophagus irregularis) as estimated by monoclonal antibody assay.

PubMed

Malekzadeh, Elham; Aliasgharzad, Nasser; Majidi, Jafar; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal

2016-10-01

Glomalin is a specific fungal glycoprotein produced by arbuscular mycorrhizal (AM) fungi belonging to the Glomerales which could efficiently sequestrate heavy metals. The glomalin has been introduced as a heat shock protein and there are evidences that increasing levels of heavy metals could enhance its production. We examined the influence of Cd concentrations on glomalin production by AM fungus, as well as its contribution to the sequestration of Cd in both pot and in vitro culture conditions. Pot experiment was carried out using pure sand with Trifolium repens L. as host plant, mycorrhized by Rhizophagus irregularis and treated with Cd levels of 0, 15, 30, and 45 μM. In vitro experiment was performed in two-compartment plates containing the transformed carrot roots mycorrhized with the same fungus and treated with Cd levels of 0, 0.001, 0.01, and 0.1 mM. The immunoreactive and Bradford reactive glomalin contents in both experiments increased as so raising Cd concentration. Total Cd sequestrated by hyphal glomalin in both cultures was significantly increased as the levels of Cd increased. The highest contents of Cd sequestration in pot (75.78 μg Cd/mg glomalin) and in vitro (11.44 μg Cd/mg glomalin) cultures were recorded at the uppermost levels of Cd, which significantly differed with other levels. Our results suggested that under Cd-induced stress, stimulated production of glomalin by AM fungus may be a protective mechanism against the toxic effect of Cd.

The effect of EDTA and citric acid on phytoremediation of Cd, Cr, and Ni from soil using Helianthus annuus.

PubMed

Turgut, Cafer; Katie Pepe, M; Cutright, Teresa J

2004-09-01

The possibility to clean heavy metal contaminated soils with hyperaccumulator plants has shown great potential. One of the most recently studied species used in phytoremediation applications are sunflowers. In this study, two cultivars of Helianthus annuus were used in conjunction with ethylene diamine tetracetic acid (EDTA) and citric acid (CA) as chelators. Two different concentrations of the chelators were studied for enhancing the uptake and translocation of Cd, Cr, and Ni from a silty-clay loam soil. When 1.0 g/kg CA was used, the highest total metal uptake was only 0.65 mg. Increasing the CA concentration posed a severe phytotoxicity to both cultivars as evidenced by stunted growth and diminished uptake rates. Decreasing the CA concentration to 0.1 and 0.3 g/kg yielded results that were not statistically different from the control. EDTA at a concentration of 0.1 g/kg yielded the best results for both cultivars achieving a total metal uptake of approximately 0.73 mg compared to approximately 0.40 mg when EDTA was present at 0.3 g/kg.

Cadmium contamination of tissues and organs of delphinids species (Stenella attenuata)--influence of biological and ecological factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andre, J.M.; Amiard, J.C.; Amiard-Triquet, C.

1990-12-01

Based on a sample of 27 dolphins (Stenella attenuata) captured in the Eastern tropical zone of the Pacific Ocean, this study was carried out to analyze the cadmium accumulation levels and distribution in 12 organs or tissue samples. The average cadmium concentrations were between 0.2 mg Cd.kg-1 in the brain and muscle and 48 mg Cd.kg-1 in the kidneys. For most of organs and tissues the average values were between 1 and 5 mg Cd.kg-1. Kidneys, liver, muscle, and intestine contained almost 85% of the total cadmium burden of all tissues considered in this study. Most of the biological andmore » ecological factors taken into account (age, sex, total weight, and length of the dolphins, weight of the organs, place and date of capture) interacted with the cadmium concentrations and burdens in the collected organs or tissues. Three factors appear to be of prime importance: age, body weight, and geographical location of the area of capture.« less

Potential risks of copper, zinc, and cadmium pollution due to pig manure application in a soil-rice system under intensive farming: a case study of Nanhu, China.

PubMed

Shi, Jiachun; Yu, Xiulin; Zhang, Mingkui; Lu, Shenggao; Wu, Weihong; Wu, Jianjun; Xu, Jianming

2011-01-01

Heavy metal (copper [Cu], zinc [Zn], and cadmium [Cd]) pollution of soils from pig manures in soil-rice ( L.) systems under intensive farming was investigated, taking Nanhu, China, as the case study area. Two hundred pig manures and 154 rice straws, brown rice samples, and corresponding surface soil (0-15 cm) samples were collected in paddy fields from 150 farms in 16 major villages within the study area. The mean Cu and Zn concentrations in pig manures consistently exceeded the related standard. About 44 and 60% of soil samples exceed the Chinese Soil Cu and Cd Environmental Quality Standards, respectively. The concentration of Cu, Zn, and Cd in brown rice did not exceed the Chinese Food Hygiene Standard. There was a significant positive correlation between total Cu and Zn contents in soil and application rate of pig manures. Strong correlation was observed between the extractable Cu, Zn, and Cd in soil and the Cu, Zn, and Cd contents in the brown rice. The spatial distribution maps of Cu and Zn concentrations in brown rice, straw, and extractable soil Cu and Zn concentration also showed similar geographical trends. Further analyses on heavy metals loading flux and accumulation rates from pig manure applied suggested that Cu and Cd contents in soil currently have already exceeded the maximum permissible limit, and Zn, if still at current manure application rates, will reach the ceiling concentration limits in 9 yr. This study assists in understanding the risk of heavy metals accumulating from pig manure applications to agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar.

PubMed

Hu, Pengjie; Ouyang, Younan; Wu, Longhua; Shen, Libo; Luo, Yongming; Christie, Peter

2015-01-01

Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. Copyright © 2014. Published by Elsevier B.V.

Influence of population density on the concentration and speciation of metals in the soil and street dust from urban areas.

PubMed

Acosta, J A; Gabarrón, M; Faz, A; Martínez-Martínez, S; Zornoza, R; Arocena, J M

2015-09-01

Street dust and soil from high, medium and low populated cities and natural area were analysed for selected physical-chemical properties, total and chemical speciation of Zn, Pb, Cu, Cr, Cd, Co, Ni to understand the influence of human activities on metal accumulation and mobility in the environment. The pH, salinity, carbonates and organic carbon contents were similar between soil and dust from the same city. Population density increases dust/soil salinity but has no influence on metals concentrations in soils. Increases in metal concentrations with population density were observed in dusts. Cu, Zn, Pb, Cr can be mobilized more easily from dust compared to the soil. In addition, population density increase the percentage of Pb and Zn associated to reducible and carbonate phase in the dust. The behaviour of metals except Cd in soil is mainly affected by physico-chemical properties, while total metal influenced the speciation except Cr and Ni in dusts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Total arsenic, lead, cadmium, copper, and zinc in some salt rivers in the northern Andes of Antofagasta, Chile.

PubMed

Queirolo, F; Stegen, S; Mondaca, J; Cortés, R; Rojas, R; Contreras, C; Munoz, L; Schwuger, M J; Ostapczuk, P

2000-06-08

The pre-Andes water in the region of Antofagasta is the main drinking and irrigation water source for approximately 3000 Atacameña (indigenous) people. The concentration for soluble elements (filtration in field through a 0.45-microm filter) was: Cd < 0.1 ng/ml; Pb < 0.5 ng/ml; and Zn and Cu between 1 and 10 ng/ml. In particulate material the concentrations were: for Cd < 0.1 ng/ml; for Pb < 0.3 ng/ml; and for Zn and Cu less than 1 ng/ml. The total content of these elements is far below the international recommendations (WHO) and the national standards (N. Ch. 1333 mod. 1987 and 409-1 of 1984). On the other hand, in some rivers a very high arsenic concentration was found (up to 3000 ng/ml) which exceed more than 50 times the national standard. In order to verify the analytical results, inter-laboratory and comparison with different determination methods have been done.

Heavy metals distribution and risk assessment in soil from an informal E-waste recycling site in Lagos State, Nigeria.

PubMed

Isimekhai, Khadijah A; Garelick, Hemda; Watt, John; Purchase, Diane

2017-07-01

Informal E-waste recycling can pose a risk to human health and the environment which this study endeavours to evaluate. The distribution of a number of heavy metals in soil from an informal recycling site in the largest market for used and new electronics and electrical equipment in West Africa was investigated. The potential bioavailability of heavy metals, extent of contamination, potential risk due to the recycling activities and impact of external factors such as rainfall were also assessed. The concentrations of all the heavy metals tested were higher in the area where burning of the waste occurred than at the control site, suggesting an impact of the recycling activities on the soil. The order of total metal concentrations was Cu > Pb > Zn > Mn > Ni > Sb > Cr > Cd for both the dry and wet seasons. The total concentrations of Cd, Cu, Mn, Ni and Zn were all significantly higher (p < 0.001) in the dry season than in the wet season. The concentrations of Cu (329-7106 mg kg -1 ), Pb (115-9623 mg kg -1 ) and Zn (508-8178 mg kg -1 ) were consistently higher than international soil guideline values. Using a sequential extraction method, the potential bioavailability of the heavy metals was indicated as Cd > Sb > Zn > Cu > Ni > Pb > Cr. When the risk was assessed using the Potential Ecological Risk Index (PERI), Cu was found to contribute the most to the potential ecological risk and Cd gave rise to the greatest concern due to its high toxic-response factor within the study site. Similarly, utilising the Risk Assessment Code (RAC) suggested that Cd posed the most risk in this site. This research establishes a high level of contamination in the study site and underscores the importance of applying the appropriate chemical speciation in risk assessment.

A novel method to generate and culture human mast cells: Peripheral CD34+ stem cell-derived mast cells (PSCMCs).

PubMed

Schmetzer, Oliver; Valentin, Patricia; Smorodchenko, Anna; Domenis, Rossana; Gri, Giorgia; Siebenhaar, Frank; Metz, Martin; Maurer, Marcus

2014-11-01

The identification and characterization of human mast cell (MC) functions are hindered by the shortage of MC populations suitable for investigation. Here, we present a novel technique for generating large numbers of well differentiated and functional human MCs from peripheral stem cells (=peripheral stem cell-derived MCs, PSCMCs). Innovative and key features of this technique include 1) the use of stem cell concentrates, which are routinely discarded by blood banks, as the source of CD34+ stem cells, 2) cell culture in serum-free medium and 3) the addition of LDL as well as selected cytokines. In contrast to established and published protocols that use CD34+ or CD133+ progenitor cells from full blood, we used a pre-enriched cell population obtained from stem cell concentrates, which yielded up to 10(8) differentiated human MCs per batch after only three weeks of culture starting with 10(6) total CD34+ cells. The total purity on MCs (CD117+, FcεR1+) generated by this method varied between 55 and 90%, of which 4-20% were mature MCs that contain tryptase and chymase and show expression of FcεRI and CD117 in immunohistochemistry. PSCMCs showed robust histamine release in response to stimulation with anti-FcεR1 or IgE/anti-IgE, and increased proliferation and differentiation in response to IL-1β or IFN-γ. Taken together, this new protocol of the generation of large numbers of human MCs provides for an innovative and suitable option to investigate the biology of human MCs. Copyright © 2014 Elsevier B.V. All rights reserved.

Inhibition effect of glyphosate on the acute and subacute toxicity of cadmium to earthworm Eisenia fetida.

PubMed

Zhou, Chui-Fan; Wang, Yu-Jun; Sun, Rui-Juan; Liu, Cun; Fan, Guang-Ping; Qin, Wen-Xiu; Li, Cheng-Cheng; Zhou, Dong-Mei

2014-10-01

The acute and subacute toxicities of cadmium (Cd) to earthworm Eisenia fetida in the presence and absence of glyphosate were studied. Although Cd is highly toxic to E. fetida, the presence of glyphosate markedly reduced the acute toxicity of Cd to earthworm; both the mortality rate of the earthworms and the accumulation of Cd decreased with the increase of the glyphosate/Cd molar ratio. The subcellular distribution of Cd in E. fetida tissues showed that internal Cd was dominant in the intact cells fraction and the heat-stable proteins fraction. The presence of glyphosate reduced the concentration of Cd in all fractions, especially the intact cells. During a longer period of exposure, the weight loss of earthworm and the total Cd absorption was alleviated by glyphosate. Thus, the herbicide glyphosate can reduce the toxicity and bioavailability of Cd in the soil ecosystems at both short- and long-term exposures. © 2014 SETAC.

Suitability of Daphnia similis as an alternative organism in ecotoxicological tests: implications for metal toxicity.

PubMed

Rodgher, Suzelei; Espíndola, Evaldo Luiz Gaeta; Lombardi, Ana Teresa

2010-08-01

The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 x 10(5) and 1 x 10(6) cells ml(-1) on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL(+) showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC(50) determination. LC(50) for D. similis was 5.15 x 10(-7) mol l(-1) dissolved Cd without algal cells, whereas with 1 x 10(5) cells ml(-1), it was significantly higher (7.15 x 10(-7) mol l(-1) dissolved Cd). For Cr, the 48 h-LC(50) value of 9.17 x 10(-7) mol l(-1) obtained for the cladoceran in tests with 1 x 10(6) cells ml(-1) of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 x 10(-7) mol l(-1) dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations.

Fungal inoculation and elevated CO2 mediate growth of Lolium mutiforum and Phytolacca americana, metal uptake, and metal bioavailability in metal-contaminated soil: evidence from DGT measurement.

PubMed

Song, Ningning; Wang, Fangli; Zhang, Changbo; Tang, Shirong; Guo, Junkang; Ju, Xuehai; Smith, Donald L

2013-01-01

Fungal inoculation and elevated CO2 may mediate plant growth and uptake of heavy metals, but little evidence from Diffusive Gradients in Thin-films (DGT) measurement has been obtained to characterize the process. Lolium mutiforum and Phytolacca americana were grown at ambient and elevated CO2 on naturally Cd and Pb contaminated soils inoculated with and without Trichoderma asperellum strain C3 or Penicillium chrysogenum strain D4, to investigate plant growth, metal uptake, and metal bioavailability responses. Fungal inoculation increased plant biomass and shoot/root Cd and Pb concentrations. Elevated CO2 significantly increased plants biomass, but decreased Cd and Pb concentrations in shoot/root to various extents, leading to a metal dilution phenomenon. Total Cd and Pb uptake by plants, and DGT-measured Cd and Pb concentrations in rhizosphere soils, were higher in all fungal inoculation and elevated CO2 treatments than control treatments, with the combined treatments having more influence than either treatment alone. Metal dilution phenomenon occurred because the increase in DGT-measured bioavailable metal pools in plant rhizosphere due to elevated CO2 was unable to match the increase in requirement for plant uptake of metals due to plant biomass increase.

Chemically enhanced phytoextraction of risk elements from a contaminated agricultural soil using Zea mays and Triticum aestivum: performance and metal mobilization over a three year period.

PubMed

Neugschwandtner, Reinhard W; Tlustos, Pavel; Komárek, Michael; Száková, Jirina; Jakoubková, Lucie

2012-09-01

Enhanced phytoextraction using EDTA for the remediation of an agricultural soil contaminated with less mobile risk elements Cd and Pb originating from smelting activities in Príbram (Czech Republic) was assessed on the laboratory and the field scale. EDTA was applied to the first years crop Zea mays. Metal mobilization and metal uptake by the plants in the soil were monitored for two additional years when Triticum aestivum was planted. The application ofEDTA effectively increased water-soluble Cd and Pb concentrations in the soil. These concentrations decreased over time. Anyhow, increased concentrations could be still observed in the third experimental year indicating a low possibility of groundwater pollution after the addition of EDTA during and also after the enhanced phytoextraction process under prevailing climatic conditions. EDTA-applications caused phytotoxicity and thereby decreased biomass production and increased Cd and Pb uptake by the plants. Phytoextraction efficiency and phytoextraction potential were too low for Cd and Pb phytoextraction in the field in a reasonable time frame (as less than one-tenth of a percent of total Cd and Pb could be removed). This strongly indicates that EDTA-enhanced phytoextraction as implemented in this study is not a suitable remediation technique for risk metal contaminated soils.

Perinatal choline deficiency delays brain development and alters metabolite concentrations in the young pig.

PubMed

Mudd, Austin T; Getty, Caitlyn M; Sutton, Brad P; Dilger, Ryan N

2016-12-01

Adequate choline supply during the perinatal period is critical for proper brain formation, when robust neurogenesis and neuronal maturation occur. Therefore, the objective of this study was to examine the impact of perinatal choline status on neurodevelopment. Sows were fed a choline-deficient (CD) or choline-sufficient (CS) diet during the last half of the gestational period. At 2 days of age, piglets from sows within each prenatal treatment group were further stratified into postnatal treatment groups and provided either a CD or CS milk replacer, resulting in four treatment groups. At 30 days of age, piglets underwent magnetic resonance imaging (MRI) procedures to analyze structural and metabolite differences. Single-voxel spectroscopy (SVS) analysis revealed postnatally CS piglets had higher (P < 0.001) concentrations of glycerophosphocholine-phosphocholine than postnatally CD piglets. Volumetric analysis indicated smaller (P < 0.006) total brain volumes in prenatally CD piglets compared with prenatally CS piglets. Differences (P < 0.05) in the corpus callosum, pons, midbrain, thalamus, and right hippocampus, were observed as larger region-specific volumes proportional to total brain size in prenatally CD piglets compared with CS piglets. Diffusion tensor imaging (DTI) suggested interactions (P < 0.05) between prenatal and postnatal choline status in fractional anisotropy values of the thalamus and right hippocampus. Prenatally CS piglets had lower cerebellar radial diffusivity (P = 0.045) compared with prenatally CD piglets. This study demonstrates that prenatal choline deficiency has profound effects by delaying neurodevelopment as evidenced by structural and metabolic MRI assessments.

The Association of Peripheral Blood Regulatory T-Cell Concentrations With Epithelial Ovarian Cancer: A Brief Report.

PubMed

Cannioto, Rikki A; Sucheston-Campbell, Lara E; Hampras, Shalaka; Goode, Ellen L; Knutson, Keith; Ness, Roberta; Modugno, Francesmary; Wallace, Paul; Szender, J Brian; Mayor, Paul; Hong, Chi-Chen; Joseph, Janine M; Friel, Grace; Davis, Warren; Nesline, Mary; Eng, Kevin H; Edwards, Robert P; Kruszka, Bridget; Schmitt, Kristina; Odunsi, Kunle; Moysich, Kirsten B

2017-01-01

There is a mounting body of evidence demonstrating higher percentages of regulatory T (Treg) cells in the peripheral blood of patients with cancer in comparison to healthy controls, but there is a paucity of epidemiological literature characterizing circulating Treg cells among patients with epithelial ovarian cancer (EOC). To investigate the role of peripheral Treg cells in ovarian neoplasms, we conducted a case-control study to characterize circulating concentrations of Treg cells among patients with EOC, women with benign ovarian conditions, and healthy controls without a history of cancer. Participants were identified for inclusion due to their participation in the Data Bank and BioRepository program at Roswell Park Cancer Institute in Buffalo, NY. Patients included 71 women with a primary diagnosis of EOC and 195 women with a diagnosis of benign ovarian conditions. Controls included 101 age- and race-matched women without a history of cancer. Nonfasting, pretreatment peripheral blood levels of CD3+CD4+CD25+FOXP3+ Treg cells were measured using flow cytometric analyses and expressed as a percentage of total CD3+ cells and as a percentage of total CD3+CD4+ cells. Compared to healthy controls and women with benign ovarian conditions, patients with EOC had significantly higher frequency of Treg cells (P < 0.04). In multivariable logistic regression analyses using Treg frequency expressed as a percentage of CD+3 cells, we observed a significant positive association between Treg cell percentage and EOC risk, with each 1% increase associated with a 37% increased risk of EOC (odds ratio, 1.37; 95% confidence interval, 1.04-1.80). We observed a similar trend when Treg frequency was expressed as a percentage of CD3+CD+4 cells (odds ratio, 1.22; 95% confidence interval, 0.99-1.49). The current study provides support that peripheral Treg cell frequency is elevated in patients with EOC in comparison to women with benign ovarian conditions and healthy controls.

The association of peripheral blood regulatory T-cell concentrations with epithelial ovarian cancer: A brief report

PubMed Central

Hampras, Shalaka; Goode, Ellen L.; Knutson, Keith; Ness, Roberta; Modugno, Francesmary; Wallace, Paul; Szender, J. Brian; Mayor, Paul; Hong, Chi-Chen; Joseph, Janine M.; Friel, Grace; Davis, Warren; Nesline, Mary; Eng, Kevin H.; Edwards, Robert P.; Kruszka, Bridget; Schmitt, Kristina; Odunsi, Kunle; Moysich, Kirsten B.

2016-01-01

Objective There is a mounting body of evidence demonstrating higher percentages of regulatory T (Treg) cells in the peripheral blood of cancer patients in comparison to healthy controls, but there is a paucity of epidemiological literature characterizing circulating Treg cells among epithelial ovarian cancer (EOC) patients. To investigate the role of peripheral Treg cells in ovarian neoplasms, we conducted a case-control study to characterize circulating concentrations of Treg cells among EOC patients, women with benign ovarian conditions, and healthy controls without a history of cancer. Materials and Methods Participants were identified for inclusion due to their participation in the Data Bank and BioRepository program at Roswell Park Cancer Institute in Buffalo, NY. Patients included 71 women with a primary diagnosis of EOC and 195 women with a diagnosis of benign ovarian conditions. Controls included 101 age- and race-matched women without a history of cancer. Non-fasting, pre-treatment peripheral blood levels of CD3+CD4+CD25+FOXP3+ Treg cells were measured using flow cytometric analyses and expressed as a percentage of total CD3+ cells and as a percentage of total CD3+CD4+ cells. Results Compared to healthy controls and women with benign ovarian conditions, EOC patients had significantly higher frequency of Treg cells (p<0.04). In multivariable logistic regression analyses utilizing Treg frequency expressed as a percentage of CD+3 cells, we observed a significant positive association between Treg cell percentage and EOC risk, with each one percent increase associated with a 37% increased risk of EOC (OR=1.37, 95% CI: 1.04-1.80). We observed a similar trend when Treg frequency was expressed as a percentage of CD3+CD+4 cells (OR=1.22, 95% CI: 0.99-1.49). Conclusions The current study provides support that peripheral Treg cell frequency is elevated in EOC patients in comparison to women with benign ovarian conditions and healthy controls. PMID:27759594

Distribution of trace metals in anchialine caves of Adriatic Sea, Croatia

NASA Astrophysics Data System (ADS)

Cuculić, Vlado; Cukrov, Neven; Kwokal, Željko; Mlakar, Marina

2011-11-01

This study presents results of the first comprehensive research on ecotoxic trace metals (Cd, Pb, Cu and Zn) in aquatic anchialine ecosystems. Data show the influence of hydrological and geological characteristics on trace metals in highly stratified anchialine water columns. Distribution of Cd, Pb, Cu and Zn in two anchialine water bodies, Bjejajka Cave and Lenga Pit in the Mljet National park, Croatia were investigated seasonally from 2006 to 2010. Behaviour and concentrations of dissolved and total trace metals in stratified water columns and metal contents in sediment, carbonate rocks and soil of the anchialine environment were evaluated. Trace metals and dissolved organic carbon (DOC) concentrations in both anchialine water columns were significantly elevated compared to adjacent seawater. Zn and Cu concentrations were the highest in the Lenga Pit water column and sediment. Elevated concentrations of Zn, Pb and Cu in Bjejajka Cave were mainly terrigenous. Significantly elevated concentrations of cadmium (up to 0.3 μg L -1) were found in the water column of Bjejajka cave, almost two orders of magnitude higher compared to nearby surface seawater. Laboratory analysis revealed that bat guano was the major source of cadmium in Bjejajka Cave. Cadmium levels in Lenga Pit, which lacks accumulations of bat guano, were 20-fold lower. Moreover, low metal amounts in carbonate rocks in both caves, combined with mineral leaching experiments, revealed that carbonates play a minor role as a source of metals in both water columns. We observed two types of vertical distribution pattern of cadmium in the stratified anchialine Bjejajka Cave water column. At lower salinities, non-conservative behaviour was characterized by strong desorption and enrichment of dissolved phase while, at salinities above 20, Cd behaved conservatively and its dissolved concentration decreased. Conservative behaviour of Cu, Pb, Zn and DOC was observed throughout the water column. After heavy rains, Cd showed reduced concentration and uniform vertical distribution, suggesting a non-terrestrial origin. Under the same conditions, concentrations of total and dissolved Pb, Cu, Zn and DOC were significantly elevated. Variations of trace metal vertical distributions in anchialine water columns were caused by large inputs of fresh water (extraordinary rainy events), and were not influenced by seasonal changes.

Circulating cadmium concentration and risk of aortic aneurysms: A nested case-control study within the Malmö Diet and Cancer cohort.

PubMed

Fagerberg, Björn; Borné, Yan; Sallsten, Gerd; Smith, J Gustav; Acosta, Stefan; Persson, Margaretha; Melander, Olle; Forsgard, Niklas; Gottsäter, Anders; Hedblad, Bo; Barregard, Lars; Engström, Gunnar

2017-06-01

Diet and smoking expose the general population to cadmium (Cd), which is a toxic metal that accumulates in the arterial wall. In experimental studies, Cd causes reductions in proliferation of smooth muscle cells and cellular synthesis of procollagen. The aim of this study was to examine whether blood Cd levels, a valid measure of Cd exposure, are associated with increased risk of abdominal aortic aneurysm (AAA). All middle-aged men and women enrolled in the Malmö Diet and Cancer study (n = 30 447) were followed from the baseline examination in 1991-1996 through 2009. A total of 297 cases with AAA and two randomly selected control subjects for each case, matched for age and sex, were included. Blood Cd was analysed by inductively coupled plasma mass spectrometry. Diagnoses of AAA, thoracic aortic aneurysm and aortic dissection were obtained from registers. Increased blood Cd was associated with increased risk of incident AAA after adjustment for smoking and other established risk factors for AAA. The highest tertile of blood Cd concentrations had a rate ratio of 2.5 (95% confidence interval 1.3, 5.0) for incident AAA. Concentration of blood Cd (log transformed) was not associated with AAA in never-smokers (n = 24). Blood Cd levels corresponding to the upper tertile of the distribution in the age- and sex-matched control group were associated with a 2.5-fold increase in rate ratio for incident AAA. This relationship was not found in the small group of never-smokers. Copyright © 2017. Published by Elsevier B.V.

Size distribution effects of cadmium tellurium quantum dots (CdS/CdTe) immunotoxicity on aquatic organisms.

PubMed

Bruneau, A; Fortier, M; Gagne, F; Gagnon, C; Turcotte, P; Tayabali, A; Davis, T L; Auffret, M; Fournier, M

2013-03-01

The increasing use of products derived from nanotechnology has raised concern about their potential toxicity to aquatic life. This study sought to examine the comparative immunotoxicity of capped cadmium sulphide/cadmium telluride (CdS/CdTe) quantum dots (QDs) and possible impact of particle/aggregate size on two bivalves (Mytilus edulis and Elliptio complanata) and a fish (Oncorhynchus mykiss). The QDs were dispersed in sterile water and fractionated using a series of micro/ultrafiltration membranes of decreasing pore size: 450 nm, 100 nm, 50 nm, 25 nm, 100 kDa (6.8 nm), 30 kDa (4.6 nm), 10 kDa (3.2 nm) and 1 kDa (1.5 nm). The total concentrations of cadmium and tellurium were determined for the filtered material and for that retained on the filters (retentate). The immunotoxicity was determined by measuring cell viability and phagocytosis. Results revealed that nanoparticles retained on the ultrafilters had a higher Cd/Te ratio compared to the permeate fraction (ratio of 5 and 2 respectively) which could indicate that the CdS core was not associated with the permeable fraction of Cd. Our results demonstrate that the toxicity of CdS/CdTe QDs was concentration and size dependent. Large CdS/CdTe QD aggregates (25 nm < size < 100 nm) reduced phagocytosis more than did smaller nanoparticles (<25 nm). Moreover, our results revealed that the different species responded differently to these fractions. Mytilus edulis hemocytes were less sensitive to CdS/CdTe QDs than the Oncorhynchus mykiss macrophage and Elliptio complanata hemocytes.

Cadmium accumulation by muskmelon under salt stress in contaminated organic soil.

PubMed

Ondrasek, Gabrijel; Gabrijel, Ondrasek; Romic, Davor; Davor, Romic; Rengel, Zed; Zed, Rengel; Romic, Marija; Marija, Romic; Zovko, Monika; Monika, Zovko

2009-03-15

Human-induced salinization and trace element contamination are widespread and increasing rapidly, but their interactions and environmental consequences are poorly understood. Phytoaccumulation, as the crucial entry pathway for biotoxic Cd into the human foodstuffs, correlates positively with rhizosphere salinity. Hypothesising that organic matter decreases the bioavailable Cd(2+) pool and therefore restricts its phytoextraction, we assessed the effects of four salinity levels (0, 20, 40 and 60 mM NaCl) and three Cd levels (0.3, 5.5 and 10.4 mg kg(-1)) in peat soil on mineral accumulation/distribution as well as vegetative growth and fruit yield parameters of muskmelon (Cucumis melo L.) in a greenhouse. Salt stress reduced shoot biomass and fruit production, accompanied by increased Na and Cl and decreased K concentration in above-ground tissues. A 25- and 50-day exposure to salinity increased Cd accumulation in leaves up to 87% and 46%, respectively. Accumulation of Cd in the fruits was up to 43 times lower than in leaves and remained unaltered by salinity. Soil contamination by Cd enhanced its accumulation in muskmelon tissues by an order of magnitude compared with non-contaminated control. In the drainage solution, concentrations of Na and Cl slightly exceeded those in the irrigation solution, whereas Cd concentration in drainage solution was lower by 2-3 orders of magnitude than the total amount added. Chemical speciation and distribution modelling (NICA-Donnan) using Visual MINTEQ showed predominance of dissolved organic ligands in Cd chemisorption and complexation in all treatments; however, an increase in salt addition caused a decrease in organic Cd complexes from 99 to 71%, with free Cd(2+) increasing up to 6% and Cd-chlorocomplexes up to 23%. This work highlights the importance of soil organic reactive surfaces in reducing trace element bioavailability and phytoaccumulation. Chloride salinity increased Cd accumulation in leaves but not in fruit peel and pulp.

Hydrous ferric oxide: evaluation of Cd-HFO surface complexation models combining Cd(K) EXAFS data, potentiometric titration results, and surface site structures identified from mineralogical knowledge.

PubMed

Spadini, Lorenzo; Schindler, Paul W; Charlet, Laurent; Manceau, Alain; Vala Ragnarsdottir, K

2003-10-01

The surface properties of ferrihydrite were studied by combining wet chemical data, Cd(K) EXAFS data, and a surface structure and protonation model of the ferrihydrite surface. Acid-base titration experiments and Cd(II)-ferrihydrite sorption experiments were performed within 3<-log[H(+)]<10.5 and 0.5<[Cd(t)]<12 mM in 0.3 M NaClO(4) at 25 degrees C, where [Cd(t)] refers to total Cd concentration. Measurements at -5.5triple bond Fe-OH(-1/2),logk((int))=-8.29, assuming the existence of a unique intrinsic microscopic constant, logk((int)), and consequently the existence of a single significant type of acid-base reactive functional groups. The surface structure model indicates that these groups are terminal water groups. The Cd(II) data were modeled assuming the existence of a single reactive site. The model fits the data set at low Cd(II) concentration and up to 50% surface coverage. At high coverage more Cd(II) ions than predicted are adsorbed, which is indicative of the existence of a second type of site of lower affinity. This agrees with the surface structure and protonation model developed, which indicates comparable concentrations of high- and low-affinity sites. The model further shows that for each class of low- and high-affinity sites there exists a variety of corresponding Cd surface complex structure, depending on the model crystal faces on which the complexes develop. Generally, high-affinity surface structures have surface coordinations of 3 and 4, as compared to 1 and 2 for low-affinity surface structures.

Dietary supplementation of probiotic Bacillus polyfermenticus, Bispan strain, modulates natural killer cell and T cell subset populations and immunoglobulin G levels in human subjects.

PubMed

Kim, Hyun-Sook; Park, Hyunjin; Cho, In-Young; Paik, Hyun-Dong; Park, Eunju

2006-01-01

A probiotic is a viable microbial dietary supplement that has beneficial effects such as prevention and treatment of specific gastrointestinal disorders, including counteracting gut barrier dysfunction associated with inflammation and infection. Probiotic Bacillus polyfermenticus, which is commonly called Bispan strain, has been appropriately used for the treatment of long-term intestinal disorders. The use of B. polyfermenticus for immune-related chronic intestinal disease may be appropriate considering that about 80% of the body's immune system is localized in the gastrointestinal tract. The current study aimed to evaluate the effect of probiotic B. polyfermenticus on the immune response of human subjects through the quantification of immune cell population and serum levels of immunoglobulins (Igs). Twenty-five male subjects, 20-35 years of age, were randomly assigned to either a control group (n =12) supplemented with a placebo or the experimental group (n = 13) supplemented with B. polyfermenticus tablets at a dose of 3.1 x 10(8) colony-forming units/day for 8 weeks. Dietary intake analyses from 3-day dietary records from three consecutive days including one weekend day and two weekdays revealed no significant differences in total energy and nutrient intakes between the two groups. The humoral immune response was monitored by the number of total B lymphocytes and serum concentrations of IgG, IgA, and IgM. To investigate the changes in immune cell populations, percentages of total T lymphocytes, CD4+ helper T cells, CD8+ cytotoxic T cells, and CD56+ natural killer (NK) cells were quantified. The concentration of IgG in the experimental group was 12% higher than in the placebo group after 8 weeks of Bispan supplementation. Also, the percentages of CD4+ helper T cells, CD8+cytotoxic T cells, and CD56+ NK cells in the Bispan strain-supplemented group were 32%, 28%, and 35% higher, respectively, compared with the control group. Because of a higher increment of the CD4+ T cell subset than CD8+ T cells, the ratio of CD4+/CD8+ T cells was greater in the experimental group. This study suggests that the supplementation of B. polyfermenticus has a potentially positive effect on immune function by enhancing IgG production as well as by modulating the number of immune cell population such as CD4+ and CD8+ T cells and NK cells.

SWASV speciation of Cd, Pb and Cu for the determination of seawater contamination in the area of the Nicole shipwreck (Ancona coast, Central Adriatic Sea).

PubMed

Annibaldi, Anna; Illuminati, Silvia; Truzzi, Cristina; Scarponi, Giuseppe

2011-12-01

The study reports for the first time on the heavy metal contamination of the waters surrounding a shipwreck lying on the sea floor. Square wave anodic stripping voltammetry has been used for a survey of the total and dissolved Cd, Pb and Cu contents of the seawater at the site of the sinking of the Nicole M/V (Coastal Adriatic Sea, Italy). Results show that the hulk has a considerable impact as regards all three metals in the bottom water, especially for the particulate fraction concentrations, which increased by factors of ≈ 9 (Cd), ≈ 3 (Pb) and ≈ 5 (Cu). The contaminated plume extended downstream for about 2 miles. Much lower contamination was observed for dissolved bottom concentrations; nevertheless Pb (0.56 ± 0.03 nmol/L) is higher than the Italian legal limits established for 2015 and Cd (0.23 ± 0.03 nmol/L) is very close the limit of Cd will be exceeded if the hulk is not removed. Copyright © 2011. Published by Elsevier Ltd.

miR-192 suppresses T follicular helper cell differentiation by targeting CXCR5 in childhood asthma.

PubMed

Zhang, Defeng; Wu, Yuanbo; Sun, Gengyun

2018-05-01

The aim of this study was to investigate the role of miR-192 in differentiation of T follicular helper cells in childhood asthma. Blood samples were taken from eighteen children with acute asthma attacks and fifteen healthy children (HC). Quantitative real-time PCR and Western blotting were used to detect the expression levels of miR-192, C-X-C chemokine receptor type 5 (CXCR5), B-cell lymphoma 6 (BCL-6) and inducible T-cell costimulator (ICOS). The flow cytometry was performed to detect the proportion of CD4 + CXCR5+ Tfh cells on CD4 + T lymphocytes. The enzyme-linked immunosorbent assay (ELISA) was carried out to determine the plasma concentrations of total IgE and IL-21. The effect of miR-192 on the T follicular helper cells differentiation by targeting CXCR5 was determined by dual-luciferase reporter assay. Children with asthma had lower levels of miR-192 than HC. The proportion of CD4 + CXCR + Tfh cells was significantly higher in the acute asthma group than HC. Similarly, the plasma concentration of total IgE and IL-21 in the acute group markedly increased compared with the HC, and IgE concentration was positively correlated with the proportion of CD4 + CXCR5 + Tfh cells. Furthermore, the expression levels of CXCR5, Bcl-6 and ICOS were significantly higher in the acute group than in the HC. While the proportion of CD4 + CXCR5 + Tfh cells, IL-21, CXCR5, Bcl-6 and ICOS were obviously lower in the CD4 + T cells transfected with miR-192 plasmid than that in miR-192 + CXCR5 group and control group. In conclusion, miR-192 blocks the activation pathway of Tfh cells by targeting CXCR5, which is a reasonable cellular target for therapeutic intervention.

[Effects of strong reductive process on transformation of heavy metals in protected vegetable soil].

PubMed

Sun, Yan Chen; Zeng, Xiang Feng; Yang, Li Qiong; Shi, Ya Nan; Chen, Xi Juan; Zhuang, Jie

2017-11-01

The application of sewage and manure in protected vegetable cultivation can induce the occurrence of heavy metals contamination. The present research studied the transformation of heavy metals (Cd, Cu, Pb and Zn) by incubating contaminated protected soil with maize straw and then leaching. The results showed that soil pH was significantly decreased, being more evident in maize straw treatment; soil Eh dropped quickly below -280 mV. Maize straw treatment promoted the activation of Cd, Cu, Pb and Zn from soil, and the total percent of oxidizable fraction and residual fraction of Cd, Cu, Pb and Zn declined at 9 th day; the amount of Cd, Cu, Pb and Zn in soil reduced 18.1%, 19.0%, 16.1% and 15.7% at 15 th day, respectively. Compared to control, maize straw treatment could increase the concentrations of dissolved Cd and Zn, but Cu decreased. The concentration of colloidal-bound Cd and Pb increased, Cu decreased and no significant change occurred in Zn in maize straw treatment. Strong reductive approach could activate heavy metals in protected vegetable soil, increase the risk of heavy metals accumulation in vegetables, and possibly cause water pollution accompanied with soil water mobilization.

Impact of vineyard abandonment and natural recolonization on metal content and availability in Mediterranean soils.

PubMed

de Santiago-Martín, Ana; Vaquero-Perea, Cristina; Valverde-Asenjo, Inmaculada; Quintana Nieto, Jose R; González-Huecas, Concepción; Lafuente, Antonio L; Vázquez de la Cueva, Antonio

2016-05-01

Abandonment of vineyards after uprooting has dramatically increased in last decades in Mediterranean countries, often followed by vegetation expansion processes. Inadequate management strategies can have negative consequences on soil quality. We studied how the age and type of vegetation cover and several environmental characteristics (lithology, soil properties, vineyard slope and so on) after vineyard uprooting and abandonment contribute to the variation patterns in total, HAc (acetic acid-method, HAc) and EDTA-extractable (ethylenediaminetetraacetic acid-method) concentrations of Cd, Cu, Pb and Zn in soils. We sampled 141 points from vineyards and abandoned vineyard Mediterranean soils recolonized by natural vegetation in recent decades. The contribution of several environmental variables (e.g. age and type of vegetation cover, lithology, soil properties and vineyard slope) to the total and extractable concentrations of metals was evaluated by canonical ordination based on redundancy analysis, considering the interaction between both environmental and response variables. The ranges of total metal contents were: 0.01-0.15 (Cd), 2.6-34 (Cu), 6.6-30 (Pb), and 29-92mgkg(-1) (Zn). Cadmium (11-100%) had the highest relative extractability with both extractants, and Zn and Pb the lowest. The total and EDTA-extractable of Cd, Pb and Zn were positively related to the age of abandonment, to the presence of Agrostis castellana and Retama sphaerocarpa, and to the contents of Fe-oxides, clay and organic matter (OM). A different pattern was noted for Cu, positively related to vineyard soils. Soil properties successfully explained HAc-extractable Cd, Cu, Pb and Zn but the age and type of vegetation cover lost significance. Clay content was negatively related to HAc-extractable Cu and Pb; and OM was positively related to HAc-Cd and Zn. In conclusion, the time elapsed after vineyard uprooting, and subsequent land abandonment, affects the soil content and availability of metals, and this impact depended on the colonizing plant species and soil properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Selenium and other elements in juvenile striped bass from the San Joaquin Valley and San Francisco Estuary, California

USGS Publications Warehouse

Saiki, Michael K.; Palawski, Donald U.

1990-01-01

Concentrations of selenium and other trace elements were determined in 55 whole body samples of juvenile anadromous striped bass (Morone saxatilis) from the San Joaquin Valley and San Francisco Estuary, California. The fish (≤1 yr old—the predominant life stage in the San Joaquin Valley) were collected in September–December 1986 from 19 sites in the Valley and 3 sites in the Estuary, and analyzed for the following elements: aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), strontium (Sr), vanadium (V), and zinc (Zn). When compared to concentrations in whole freshwater fish measured by surveys from other waters, a few samples contained higher levels, of As, Cd, Cu, Pb, and Se. The median concentrations of Al, As, Cu, Fe, Mg, Se, and Sr also differed significantly (P⩽0.05) among sites. However, only Se concentrations were highest (up to 7.9 μg/g dry weight) in samples from Valley sites exposed to agricultural subsurface (tile) drainwater; concentrations were lower in samples collected elsewhere. Water quality variables—especially those strongly influenced by tile drainwater (conductivity, total dissolved solids, total alkalinity, and total hardness)—were also significantly correlated (P⩽0.05) with Se concentrations in fish. Selenium concentrations in striped bass from the Estuary were only one-fourth to one-half the concentrations measured in the most contaminated fish from the San Joaquin River.

Cadmium tolerance and accumulation in cultivars of a high-biomass tropical tree (Averrhoa carambola) and its potential for phytoextraction.

PubMed

Li, J T; Liao, B; Lan, C Y; Ye, Z H; Baker, A J M; Shu, W S

2010-01-01

Averrhoa carambola is a high-biomass tropical tree that has been identified as a Cd accumulator. In the present study, field survey, pot, and hydroponic experiments were conducted to investigate the variation of Cd tolerance and accumulation in cultivars of A. carambola as well as its potential for phytoextraction. In the field survey, it was found that concentrations of Cd in aerial tissues of A. carambola varied greatly among sites and cultivars. The Cd bioconcentration factors (BCFs) and Cd removals by the field-grown A. carambola differed significantly among sites but not among cultivars. Nonetheless, all four carambola cultivars investigated were able to accumulate considerably high concentrations of Cd in their shoots, which indicated that the 4-yr-old carambola stands could remove 0.3 to 51.8% of the total Cd content in the top 20-cm soil layer. When cultured in Cd-spiked soils, the carambola cultivar Hua-Di always showed higher Cd tolerance than the other cultivars; however, this tendency was not confirmed by hydroponic experiment. The Cd BCFs of cultivar Thailand grown in soils with 6 and 12 mg Cd kg(-1) were highest among cultivars, whereas this trend was reversed at 120 mg Cd kg(-1) treatment. Nevertheless, the pot- and hydroponics-grown carambola cultivars generally showed higher capacities to tolerate and accumulate Cd, compared with the control species. The present results indicate that a strong ability to tolerate and accumulate Cd seems to be a trait at the species level in A. carambola, although some degree of variances in both Cd tolerance and accumulation exists among cultivars.

Characterization of polycyclic aromatic hydrocarbons in fugitive PM10 emissions from an integrated iron and steel plant.

PubMed

Khaparde, V V; Bhanarkar, A D; Majumdar, Deepanjan; Rao, C V Chalapati

2016-08-15

Fugitive emissions of PM10 (particles <10μm in diameter) and associated polycyclic aromatic hydrocarbons (PAHs) were monitored in the vicinity of coking unit, sintering unit, blast furnace and steel manufacturing unit in an integrated iron and steel plant situated in India. Concentrations of PM10, PM10-bound total PAHs, benzo (a) pyrene, carcinogenic PAHs and combustion PAHs were found to be highest around the sintering unit. Concentrations of 3-ring and 4-ring PAHs were recorded to be highest in the coking unit whereas 5-and 6-ring PAHs were found to be highest in other units. The following indicatory PAHs were identified: indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, benzo (k) fluoranthene in blast furnace unit; indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, chrysene in sintering unit; Anthracene, fluoranthene, chrysene in coking unit and acenaphthene, fluoranthene, fluorene in steel making unit. Total-BaP-TEQ (Total BaP toxic equivalent quotient) and BaP-MEQ (Total BaP mutagenic equivalent quotient) concentration levels ranged from 2.4 to 231.7ng/m(3) and 1.9 to 175.8ng/m(3), respectively. BaP and DbA (dibenzo (a,h) anthracene) contribution to total-BaP-TEQ was found to be the highest. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial distribution of heavy metals in soil, water, and vegetables of farms in Sanandaj, Kurdistan, Iran.

PubMed

Maleki, Afshin; Amini, Hassan; Nazmara, Shahrokh; Zandi, Shiva; Mahvi, Amir Hossein

2014-01-01

Heavy metals are ubiquitous elsewhere in nature and their measurement in environment is necessary to develop health management strategies. In this study, we aimed to find out concentrations and spatial patterns of heavy metals in main farms of Sanandaj in Kurdistan, Iran. Over May to October 2012, six farms were selected to analyze concentrations and spatial patterns of several heavy metals, namely aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in their soil, irrigation water, and edible vegetables. Overall, 36 samples of soil and water and 72 samples of vegetables including coriander (Coriandrum sativum), dill (Anethum graveolens), radish (Raphanus sativus) root and radish leaf were collected. The concentrations of metals were determined by inductively coupled plasma optical emission spectrometry. The spatial surfaces of heavy metals were created using geospatial information system. The order of metals in soil was Al > Zn > Ni > Cu > Cr > Pb > Co > As > Cd while in water it was Cr > Co > Zn > Pb > Cu > Ni > Al = As = Cd. The order of heavy metals in vegetables was Al > Zn > Cu > Cr > Ni > Pb > Co > As > Cd. Totally, the minimum concentrations of Al, Cu, Pb, and Zn were found in radish root while the maximum of Al, Co, Cr, and Ni were found in radish leaf. The minimum concentrations of Cd and Cr and maximum concentrations of Cu and Zn were also deciphered in dill. Noteworthy, coriander had the minimum concentrations of Co and Ni. The concentrations of Cr and Pb in vegetables were more than maximum allowable limits of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). In summary, albeit the concentrations of heavy metals in soil and water samples were below FAO and the WHO standards, vegetables were contaminated by chromium and lead.

Cadmium-induced glutathionylation of actin occurs through a ROS-independent mechanism: Implications for cytoskeletal integrity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choong, Grace; Liu, Ying; Xiao, Weiqun

2013-10-15

Cadmium disrupts the actin cytoskeleton in rat mesangial cells, and we have previously shown that this involves a complex interplay involving activation of kinase signaling, protein translocation, and disruption of focal adhesions. Here we investigate the role that glutathionylation of actin plays in Cd{sup 2+}-associated cytoskeletal reorganization. Low concentrations of Cd{sup 2+} (0.5–2 μM) caused an increase in actin glutathionylation by 6 h, whereas at higher concentrations glutathionylation remained at basal levels. Although oxidation with diamide increased glutathionylation, reactive oxygen species (ROS) were not involved in the Cd{sup 2+}-dependent effect, as only Cd{sup 2+} concentrations above 2 μM were sufficientmore » to increase ROS. However, low [Cd{sup 2+}] increased total glutathione levels without affecting the ratio of reduced/oxidized glutathione, and inhibition of glutathione synthesis suppressed actin glutathionylation. Cadmium increased the activity of the enzyme glutaredoxin, which influences the equilibrium between glutathionylated and deglutathionylated proteins and thus may influence levels of glutathionylated actin. Together these observations show that cadmium-dependent effects on actin glutathionylation are affected by glutathione metabolism and not by direct effects of ROS on thiol chemistry. In vitro polymerization assays with glutathionylated actin show a decreased rate of polymerization. In contrast, immunofluorescence of cytoskeletal structure in intact cells suggests that increases in actin glutathionylation accompanying increased glutathione levels occurring under low Cd{sup 2+} exposure are protective in vivo, with cytoskeletal disruption ensuing only when higher Cd{sup 2+} concentrations increase ROS levels and prevent an increase in actin–glutathione conjugates. - Highlights: • Cadmium disrupts the actin cytoskeleton in mesangial cells. • Cadmium induces glutathionylation of actin at low concentrations. • Glutathionylation requires glutathione synthesis but is independent of ROS. • Glutathionylation is protective against cytoskeletal disruption at low cadmium.« less

Bioaccessibility of As, Cd, Cu, Ni, Pb, and Sb in toys and low-cost jewelry.

PubMed

Guney, Mert; Zagury, Gerald J

2014-01-21

Children can be exposed to toxic elements in toys and jewelry following ingestion. As, Cd, Cu, Ni, Pb, and Sb bioavailability was assessed (n = 24) via the in vitro gastrointestinal protocol (IVG), the physiologically based extraction test (PBET), and the European Toy Safety Standard protocol (EN 71-3), and health risks were characterized. Cd, Cu, Ni, and Pb were mobilized from 19 metallic toys and jewelry (MJ) and one crayon set. Bioaccessible Cd, Ni, or Pb exceeded EU migratable concentration limits in four to six MJ, depending on the protocol. Using two-phase (gastric + intestinal) IVG or PBET might be preferable over EN 71-3 since they better represent gastrointestinal physiology. Bioaccessible and total metal concentrations were different and not always correlated, indicating that bioaccessibility measurement may provide more accurate risk characterization. More information on impacts of multiple factors affecting metals mobilization from toys and jewelry is needed before recommending specific tests. Hazard index (HI) for Cd, Ni, or Pb were >1 for all six MJ exceeding the EU limits. For infants (6-12 mo old), 10 MJ had HI > 1 for Cd, Cu, Ni, or Pb (up to 75 for Cd and 43 for Pb). Research on prolonged exposure to MJ and comprehensive risk characterization for toys and jewelry exposure is recommended.

Source Apportionment and Influencing Factor Analysis of Residential Indoor PM2.5 in Beijing

PubMed Central

Yang, Yibing; Liu, Liu; Xu, Chunyu; Li, Na; Liu, Zhe; Wang, Qin; Xu, Dongqun

2018-01-01

In order to identify the sources of indoor PM2.5 and to check which factors influence the concentration of indoor PM2.5 and chemical elements, indoor concentrations of PM2.5 and its related elements in residential houses in Beijing were explored. Indoor and outdoor PM2.5 samples that were monitored continuously for one week were collected. Indoor and outdoor concentrations of PM2.5 and 15 elements (Al, As, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Pb, Se, Tl, V, Zn) were calculated and compared. The median indoor concentration of PM2.5 was 57.64 μg/m3. For elements in indoor PM2.5, Cd and As may be sensitive to indoor smoking, Zn, Ca and Al may be related to indoor sources other than smoking, Pb, V and Se may mainly come from outdoor. Five factors were extracted for indoor PM2.5 by factor analysis, explained 76.8% of total variance, outdoor sources contributed more than indoor sources. Multiple linear regression analysis for indoor PM2.5, Cd and Pb was performed. Indoor PM2.5 was influenced by factors including outdoor PM2.5, smoking during sampling, outdoor temperature and time of air conditioner use. Indoor Cd was affected by factors including smoking during sampling, outdoor Cd and building age. Indoor Pb concentration was associated with factors including outdoor Pb and time of window open per day, building age and RH. In conclusion, indoor PM2.5 mainly comes from outdoor sources, and the contributions of indoor sources also cannot be ignored. Factors associated indoor and outdoor air exchange can influence the concentrations of indoor PM2.5 and its constituents. PMID:29621164

Source Apportionment and Influencing Factor Analysis of Residential Indoor PM2.5 in Beijing.

PubMed

Yang, Yibing; Liu, Liu; Xu, Chunyu; Li, Na; Liu, Zhe; Wang, Qin; Xu, Dongqun

2018-04-05

In order to identify the sources of indoor PM 2.5 and to check which factors influence the concentration of indoor PM 2.5 and chemical elements, indoor concentrations of PM 2.5 and its related elements in residential houses in Beijing were explored. Indoor and outdoor PM 2.5 samples that were monitored continuously for one week were collected. Indoor and outdoor concentrations of PM 2.5 and 15 elements (Al, As, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Pb, Se, Tl, V, Zn) were calculated and compared. The median indoor concentration of PM 2.5 was 57.64 μg/m³. For elements in indoor PM 2.5 , Cd and As may be sensitive to indoor smoking, Zn, Ca and Al may be related to indoor sources other than smoking, Pb, V and Se may mainly come from outdoor. Five factors were extracted for indoor PM 2.5 by factor analysis, explained 76.8% of total variance, outdoor sources contributed more than indoor sources. Multiple linear regression analysis for indoor PM 2.5 , Cd and Pb was performed. Indoor PM 2.5 was influenced by factors including outdoor PM 2.5 , smoking during sampling, outdoor temperature and time of air conditioner use. Indoor Cd was affected by factors including smoking during sampling, outdoor Cd and building age. Indoor Pb concentration was associated with factors including outdoor Pb and time of window open per day, building age and RH. In conclusion, indoor PM 2.5 mainly comes from outdoor sources, and the contributions of indoor sources also cannot be ignored. Factors associated indoor and outdoor air exchange can influence the concentrations of indoor PM 2.5 and its constituents.

Stabilization of Pb and Cd contaminated soils and soil quality improvements using waste oyster shells.

PubMed

Ok, Yong Sik; Lim, Jung Eun; Moon, Deok Hyun

2011-02-01

Large amounts of oyster shells are produced as a by-product of shellfish farming in coastal regions without beneficial use options. Accordingly, this study was conducted to evaluate the potential for the use of waste oyster shells (WOS) containing a high amount of CaCO₃ to improve soil quality and to stabilize heavy metals in soil. To accomplish this, an incubation experiment was conducted to evaluate the ability of the addition of 1-5 wt% WOS to stabilize the Pb (total 1,246 mg/kg) and Cd (total 17 mg/kg) in a contaminated soil. The effectiveness of the WOS treatments was evaluated using various single extraction techniques. Soil amended with WOS was cured for 30 days complied with the Korean Standard Test method (0.1 M·HCl extraction). The Pb and Cd concentrations were less than the Korean warning and countermeasure standards following treatment with 5 wt% WOS. Moreover, the concentrations of Cd were greatly reduced in response to WOS treatment following extraction using 0.01 M·CaCl₂, which is strongly associated with phytoavailability. Furthermore, the soil pH and exchangeable Ca increased significantly in response to WOS treatment. Taken together, the results of this study indicated that WOS amendments improved soil quality and stabilized Pb and Cd in contaminated soil. However, extraction with 0.43 M·CH₃ COOH revealed that remobilization of heavy metals can occur when the soil reaches an acidic condition.

Heavy metals in urban soils of East St. Louis, IL, Part I: Total concentration of heavy metals in soils.

PubMed

Kaminski, M D; Landsberger, S

2000-09-01

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produce organic and inorganic chemicals, and petroleum refineries. A protocol for soil analysis was developed to produce sufficient information on the extent of heavy metal contamination in East St. Louis soils. Soil cores representing every borough of East St. Louis were analyzed for heavy metals--As, Cd, Cu, Cr, Hg, Ni, Pb, Sb, Sn, and Zn. The topsoil contained heavy metal concentrations as high as 12.5 ppm Cd, 14,400 ppm Cu, ppm quantities of Hg, 1860 ppm Pb, 40 ppm Sb, 1130 ppm Sn, and 10,360 ppm Zn. Concentrations of Sb, Cu, and Cd were well correlated with Zn concentrations, suggesting a similar primary industrial source. In a sandy loam soil from a vacated rail depot near the bank of the Mississippi River, the metals were evenly distributed down to a 38-cm depth. The clay soils within a half-mile downwind of the Zn smelter and Cu products company contained elevated Cd (81 ppm), Cu (340 ppm), Pb (700 ppm), and Zn (6000 ppm) and displayed a systematic drop in concentration of these metals with depth. This study demonstrates the often high concentration of heavy metals heterogeneously distributed in the soil and provides baseline data for continuing studies of heavy metal soil leachability.

Human exposure to lead, cadmium and mercury through fish and seafood product consumption in Italy: a pilot evaluation.

PubMed

Pastorelli, A A; Baldini, M; Stacchini, P; Baldini, G; Morelli, S; Sagratella, E; Zaza, S; Ciardullo, S

2012-01-01

The presence of selected toxic heavy metals, such as cadmium (Cd), lead (Pb) and mercury (Hg), was investigated in fish and seafood products, namely, blue mussel, carpet shell clam, European squid, veined squid, deep-water rose shrimp, red mullet, European seabass, gilthead seabream, Atlantic cod, European hake, Atlantic bluefin tuna and swordfish so as to assess their human exposure through diet. Metals were detected by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and hydride generation atomic absorption spectrometry (Hg-AAS). Measurements of Cd, Pb and Hg were performed by means of analytical methods validated in compliance with UNI CEI EN ISO/IEC 17025 [2005. General requirements for the competence of testing and calibration laboratories. Milano (Italy): UNI Ente Nazionale Italiano di Unificazione]. The exposure assessment was undertaken matching the levels of Cd, Pb and total Hg with consumption data related to fish and seafood products selected for this purpose. In order to establish human health implications, the estimated weekly intakes (EWIs) for Cd, Pb and Hg were compared with the standard tolerable weekly intakes (TWI) for Cd and provisional tolerable weekly intakes (PTWIs) for Pb and Hg stipulated by the European Food Safety Authority (EFSA) and the Food and Agriculture Organization/World Health Organization (FAO/WHO) Joint Expert Committee on Food Additives (JECFA). The found metal concentrations were largely below the maximum levels (MLs) established at the European Union level with the exception of Cd. This metal exceeded the MLs in squid, red mullet, European hake and Atlantic cod. Squid and blue mussel showed the highest Pb concentrations which accounted for 60% and 10% of the MLs, respectively. Highest Hg levels were found in predatory fish. The concentrations of Hg in swordfish, Atlantic bluefin tuna and red mullet accounted for 50%, 30% and 30% of the MLs, respectively. The EWIs for Cd, Pb and Hg related to the consumption of fish and seafood products by the median of the Italian total population accounted for 20%, 1.5% and 10% of the standard TWI for Cd as well as PTWIs for Pb and Hg, respectively. Furthermore, the EWIs estimated using consumption data concerning Italian consumers did not exceed the standard TWI and PTWIs, except for Cd at 95th percentile.

Concentrations and health risk assessment of trace elements in animal-derived food in southern China.

PubMed

Wu, Yaketon; Zhang, Huimin; Liu, Guihua; Zhang, Jianqing; Wang, Jizhong; Yu, Yingxin; Lu, Shaoyou

2016-02-01

This study aimed to investigate the levels of trace elements in animal-derived food in Shenzhen, Southern China. The concentrations of 14 trace elements (Cd, Hg, Pb, As, Cr, Cu, Fe, Zn, Mn, Mo, Ni, Co, Se and Ti) in a total of 220 meat samples, collected from the local markets of Shenzhen were determined. Cu, Fe and Zn were the major elements, with concentrations approximately 2-3 orders of magnitude higher than those of other elements. However, the daily intakes of Cu, Fe and Zn merely via the consumption of the meat products were lower than the recommended nutrient intake values provided by the 2013 Chinese Dietary Guide. Among the non-essential trace elements, Cd was accumulated in animal viscera, and the concentration ratios of chicken gizzard/chicken, chicken liver/chicken, pig kidney/pork and pig liver/pork were 41.6, 55.2, 863 and 177, respectively. In addition, high concentrations of As were found in aquatic products, especially in marine fish. The concentration of As in marine fish was slightly higher than the limits recommended by China, USA and Croatia. The health risk assessment of trace elements through the consumption of meat products by adult residents in Shenzhen was evaluated by using the target hazard quotient (THQ) method. The total THQ was greater than 1, implying a potential health risk. Approximately 66% of total THQ values, mainly from As, were from the consumption of aquatic products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Source identification of eight hazardous heavy metals in agricultural soils of Huizhou, Guangdong Province, China.

PubMed

Cai, Limei; Xu, Zhencheng; Ren, Mingzhong; Guo, Qingwei; Hu, Xibang; Hu, Guocheng; Wan, Hongfu; Peng, Pingan

2012-04-01

One hundred and four surface samples and 40 profiles samples in agricultural soils collected from Huizhou in south-east China were monitored for total contents of 8 heavy metals, and analyzed by multivariate statistical techniques and enrichment factor (EF), in order to investigate their origins. The results indicate that the concentrations of Cu, Zn, Ni, Cr, Pb, Cd, As and Hg in soils are 16.74, 57.21, 14.89, 27.61, 44.66, 0.10, 10.19 and 0.22 mg/kg, respectively. Compared to the soil background contents in Guangdong Province, the mean concentrations of Hg, Cd, Zn, Pb and As in soil of Huizhou are higher, especially Hg and Cd, which are 2.82 and 1.79 times the background values, respectively. Cr, Ni, Cu, partially, Zn and Pb mainly originate from a natural source. Cd, As, partially, Zn mainly come from agricultural practices. However, Hg, partially, Pb originate mainly from industry and traffic sources. Copyright © 2011 Elsevier Inc. All rights reserved.

[Analysis of genomic DNA methylation level in radish under cadmium stress by methylation-sensitive amplified polymorphism technique].

PubMed

Yang, Jin-Lan; Liu, Li-Wang; Gong, Yi-Qin; Huang, Dan-Qiong; Wang, Feng; He, Ling-Li

2007-06-01

The level of cytosine methylation induced by cadmium in radish (Raphanus sativus L.) genome was analysed using the technique of methylation-sensitive amplified polymorphism (MSAP). The MSAP ratios in radish seedling exposed to cadmium chloride at the concentration of 50, 250 and 500 mg/L were 37%, 43% and 51%, respectively, and the control was 34%; the full methylation levels (C(m)CGG in double strands) were at 23%, 25% and 27%, respectively, while the control was 22%. The level of increase in MSAP and full methylation indicated that de novo methylation occurred in some 5'-CCGG sites under Cd stress. There was significant positive correlation between increase of total DNA methylation level and CdCl(2) concentration. Four types of MSAP patterns: de novo methylation, de-methylation, atypical pattern and no changes of methylation pattern were identified among CdCl(2) treatments and the control. DNA methylation alteration in plants treated with CdCl(2) was mainly through de novo methylation.

Fish protein substrates can substitute effectively for poultry by-product meal when incorporated in high-quality senior dog diets.

PubMed

Zinn, K E; Hernot, D C; Fastinger, N D; Karr-Lilienthal, L K; Bechtel, P J; Swanson, K S; Fahey, G C

2009-08-01

An experiment was conducted to analytically define several novel fish substrates and determine the effects of feeding diets containing these substrates on total tract nutrient digestibilities and on immune status of senior dogs. The control diet contained poultry by-product meal while test diets contained 20% milt meal (MM), pink salmon hydrolysate (PSH) and white fish meal (WFM) added at the expense of poultry by-product meal. Concentrations of lymphocytes positive for CD3, CD4, CD8 and CD21 cell-surface markers and immunoglobulin concentrations were measured. Gene expression of cytokines tumour necrosis factor (TNF)-, interleukin (IL)-6, interferon (IFN)-, IL-10 and transforming growth factor (TGF)-β was determined by quantitative real-time polymerase chain reaction. Major compositional differences were noted among fish substrates but apparent nutrient digestibility coefficients and immune indices were not affected by treatment. Fish protein substrates were found to be effective substitutes for poultry by-product meal, providing diets of high nutritive value for senior dogs.

Kinetic determinations of trace element bioaccumulation in the mussel Mytilus edulis

USGS Publications Warehouse

Wang, W.-X.; Fisher, N.S.; Luoma, S.N.

1996-01-01

Laboratory experiments employing radiotracer methodology were conducted to determine the assimilation efficiencies from ingested natural seston, the influx rates from the dissolved phase and the efflux rates of 6 trace elements (Ag, Am, Cd, Co, Se and Zn) in the mussel Mytilus edulis. A kinetic model was then employed to predict trace element concentration in mussel tissues in 2 locations for which mussel and environmental data are well described: South San Francisco Bay (California, USA) and Long Island Sound (New York, USA). Assimilation efficiencies from natural seston ranged from 5 to 18% for Ag, 0.6 to 1% for Am, 8 to 20% for Cd, 12 to 16% for Co, 28 to 34% for Se, and 32 to 41% for Zn. Differences in chlorophyll a concentration in ingested natural seston did not have significant impact on the assimilation of Am, Co, Se and Zn. The influx rate of elements from the dissolved phase increased with the dissolved concentration, conforming to Freundlich adsorption isotherms. The calculated dissolved uptake rate constant was greatest for Ag, followed by Zn > Am = Cd > Co > Se. The estimated absorption efficiency from the dissolved phase was 1.53% for Ag, 0.34% for Am, 0.31% for Cd, 0.11% for Co, 0.03% for Se and 0.89% for Zn. Salinity had an inverse effect on the influx rate from the dissolved phase and dissolved organic carbon concentration had no significant effect on trace element uptake. The calculated efflux rate constants for all elements ranged from 1.0 to 3.0% d-1. The route of trace element uptake (food vs dissolved) and the duration of exposure to dissolved trace elements (12 h vs 6 d) did not significantly influence trace element efflux rates. A model which used the experimentally determined influx and efflux rates for each of the trace elements, following exposure from ingested food and from water, predicted concentrations of Ag, Cd, Se and Zn in mussels that were directly comparable to actual tissue concentrations independently measured in the 2 reference sites in national monitoring programs. Sensitivity analysis indicated that the total suspended solids load, which can affect mussel feeding activity, assimilation, and trace element concentration in the dissolved and particulate phases, can significantly influence metal bioaccumulation for particle-reactive elements such as Ag and Am. For all metals, concentrations in mussels are proportionately related to total metal load in the water column and their assimilation efficiency from ingested particles. Further, the model predicted that over 96% of Se in mussels is obtained from ingested food, under conditions typical of coastal waters. For Ag, Am, Cd, Co and Zn, the relative contribution from the dissolved phase decreases significantly with increasing trace element partition coefficients for suspended particles and the assimilation efficiency in mussels of ingested trace elements; values range between 33 and 67% for Ag, 5 and 17% for Am, 47 and 82% for Cd, 4 and 30% for Co, and 17 and 51% for Zn.

Level, source identification, and risk analysis of heavy metal in surface sediments from river-lake ecosystems in the Poyang Lake, China.

PubMed

Zhang, Hua; Jiang, Yinghui; Ding, Mingjun; Xie, Zhenglei

2017-09-01

The concentrations, sources, and risks of heavy metals (Fe, Al, Mn, Cr, Co, Ni, Cu, Zn, As, Cd, W, Pb, and Tl) in sediments in five river-lake ecosystems in the Poyang Lake region were studied. The concentrations of the heavy metals varied spatially, with most of the highest concentrations in the Raohe river-lake ecosystem (RH). All heavy metals except As, Cd, W, and Tl were enriched in sediments possessing high total organic carbon contents or in finer sediments. Based on enrichment factors and statistical methods, it was found that Cd in sediments in the Xiushui (XS), Ganjiang (GJ), Xinjiang (XJ) river-lake ecosystems, and RH; Mn in the XS, GJ, and RH; and W in the XS and GJ were greatly affected by anthropogenic inputs. Moreover, the origins of Cu, Zn, and As require more attention due to the high concentrations found. The high enrichment factor of Cd in the sediments indicated that this metal might cause significant pollution in the environment. The results of the modified potential ecological risk index revealed that the XS, GJ, RH, and XJ were at considerable ecological risk, while the sediments in the Fuhe river-lake ecosystem (FH) were at moderate ecological risk, with Cd contributing the highest proportion of risk. The hazard score fundamentally validated the modified potential ecological risk analysis and revealed a mean toxicity of 57.80% to the benthic organisms in the RH.

Cadmium body burden and increased blood pressure in middle-aged American Indians: the Strong Heart Study.

PubMed

Franceschini, N; Fry, R C; Balakrishnan, P; Navas-Acien, A; Oliver-Williams, C; Howard, A G; Cole, S A; Haack, K; Lange, E M; Howard, B V; Best, L G; Francesconi, K A; Goessler, W; Umans, J G; Tellez-Plaza, M

2017-03-01

Cadmium (Cd) is an environmental pollutant that has been associated with cardiovascular disease in populations, but the relationship of Cd with hypertension has been inconsistent. We studied the association between urinary Cd concentrations, a measure of total body burden, and blood pressure in American Indians, a US population with above national average Cd burden. Urinary Cd was measured using inductively coupled plasma mass spectrometry, and adjusted for urinary creatinine concentration. Among 3714 middle-aged American Indian participants of the Strong Heart Study (mean age 56 years, 41% male, 67% ever-smokers, 23% taking antihypertensive medications), urinary Cd ranged from 0.01 to 78.48 μg g -1 creatinine (geometric mean=0.94 μg g -1 ) and it was correlated with smoking pack-year among ever-smokers (r 2 =0.16, P<0.0001). Participants who were smokers were on average light-smokers (mean 10.8 pack-years), and urinary Cd was similarly elevated in light- and never-smokers (geometric means of 0.88 μg g -1 creatinine for both categories). Log-transformed urinary Cd was significantly associated with higher systolic blood pressure in models adjusted for age, sex, geographic area, body mass index, smoking (ever vs never, and cumulative pack-years) and kidney function (mean blood pressure difference by lnCd concentration (β)=1.64, P=0.002). These associations were present among light- and never-smokers (β=2.03, P=0.002, n=2627), although not significant among never-smokers (β=1.22, P=0.18, n=1260). Cd was also associated with diastolic blood pressure among light- and never-smokers (β=0.94, P=0.004). These findings suggest that there is a relationship between Cd body burden and increased blood pressure in American Indians, a population with increased cardiovascular disease risk.

Genotoxic effect of Pb and Cd on in vitro cultures of Sphagnum palustre: An evaluation by ISSR markers.

PubMed

Sorrentino, Maria Cristina; Capozzi, Fiore; Giordano, Simonetta; Spagnuolo, Valeria

2017-08-01

In the present work, the genotoxic effect of cadmium and lead supplied in a laboratory trial, was investigated for the first time in the moss Sphagnum palustre, by ISSR molecular markers. A total of 169 reproducible bands were obtained with 12 primers, ten of which gave polymorphisms (i.e., appearance/disappearance of bands), indicating a clear genotoxic effect induced by the metals. Both metals induced a decrease of the genome template stability in a dose dependent manner. At concentration >10 -5 Cd also induced a general toxic effect in S. palustre, leading to chlorophyll degradation and moss death. Moreover, we followed the fate of supplied heavy metals into the moss tissue by SEM-EDX to see if they entered the cells. SEM-EDX observations on moss cultures treated with equimolar concentrations of the two metals showed that most Pb precipitated in form of particles on moss surface, while Cd did not aggregate in particles and was not found on moss surface. In light of these findings, we concluded that probably Pb induced a genotoxic effect at lower intracellular concentrations than Cd. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ecological risks and potential sources of heavy metals in agricultural soils from Huanghuai Plain, China.

PubMed

Zhou, Lingli; Yang, Bing; Xue, Nandong; Li, Fasheng; Seip, Hans Martin; Cong, Xin; Yan, Yunzhong; Liu, Bo; Han, Baolu; Li, Huiying

2014-01-01

A total of 224 agricultural soil samples from Huanghuai Plain in China were investigated for the concentrations of seven heavy metals (As, Cd, Cr, Hg, Ni, Pb, and Zn). The mean concentrations of the metals were 12, 0.17, 79, 0.04, 35, 25, and 74 mg/kg, respectively. These values are similar or slightly higher than background values in this region, except for Cd with a mean nearly twice the background value. The estimated ecological risks based on contamination factors and potential ecological risk indexes are also mostly low, but considerable for Cd and Hg. Multivariate analysis (including Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis) clearly revealed three distinct metal groups, i.e., Cr/Ni/Zn, As/Cd/Pb, and Hg, whose concentrations were closely associated with the distribution and pollution characteristics of industries in and around the plain. The main anthropogenic sources for the three metal groups were identified as atmospheric deposition, sewage irrigation/fertilizers usage, and atmospheric deposition/irrigation water, respectively. The present results are well suited for planning, risk assessment, and decision making by environmental managers of this region.

Use of human milk in the assessment of toxic metal exposure and essential element status in breastfeeding women and their infants in coastal Croatia.

PubMed

Grzunov Letinić, Judita; Matek Sarić, Marijana; Piasek, Martina; Jurasović, Jasna; Varnai, Veda Marija; Sulimanec Grgec, Antonija; Orct, Tatjana

2016-12-01

Pregnant and lactating women and infants are vulnerable population groups for adverse effects of toxic metals due to their high nutritional needs and the resultant increased gastrointestinal absorption of both, essential and toxic elements. Although breastfeeding is recommended for infants worldwide, as human milk is the best source of nutrients and other required bioactive factors, it is also a pathway of maternal excretion of toxic substances including toxic metals and thus a source of infant exposure. The aim of this research was to assess health risks in breastfeeding women in the coastal area of the Republic of Croatia and their infants (N=107) due to maternal exposure to Cd and Pb via cigarette smoking, and Hg via seafood and dental amalgam fillings, and their interaction with essential elements. Biological markers of exposure were the concentrations of main toxic metals Pb, Cd and Hg in maternal blood and three types of breast milk throughout lactation stages. Biological markers of effects were the levels of essential elements Ca, Fe, Cu, Zn and Se in maternal serum and breast milk. With regard to cigarette smoking as a source of exposure to Cd and Pb, there were effects of smoking on Cd concentration in blood and correlations between the smoking index and Cd concentrations in maternal blood (ρ=0.593; P<0.001) and mature milk (ρ=0.271; P=0.011) and Pb concentration in transitional milk (ρ=0.280; P=0.042). Regarding fish, we found correlations between weekly consumption frequency and total Hg concentrations in maternal blood (ρ=0.292; P=0.003) and mature milk (ρ=0.303; P=0.003). The number of dental amalgam fillings correlated with total Hg concentrations in colostrum (ρ=0.489; P=0.005) and transitional milk (ρ=0.309; P=0.018). As for the essential element status, only Se levels in maternal serum decreased by 10% in persons who continued smoking during pregnancy compared to non-smokers. In conclusion, the levels of main toxic metals Cd, Pb and Hg and essential elements Ca, Fe, Cu, Zn and Se in maternal blood and three types of breast milk samples in the studied area of coastal Croatia showed no risk of disrupted essential element levels with regard of toxic metal exposure in both breastfeeding women and their infants. Copyright © 2016 Elsevier GmbH. All rights reserved.

Effects of cooking and subcellular distribution on the bioaccessibility of trace elements in two marine fish species.

PubMed

He, Mei; Ke, Cai-Huan; Wang, Wen-Xiong

2010-03-24

In current human health risk assessment, the maximum acceptable concentrations of contaminants in food are mostly based on the total concentrations. However, the total concentration of contaminants may not always reflect the available amount. Bioaccessibility determination is thus required to improve the risk assessment of contaminants. This study used an in vitro digestion model to assess the bioaccessibility of several trace elements (As, Cd, Cu, Fe, Se, and Zn) in the muscles of two farmed marine fish species (seabass Lateolabrax japonicus and red seabream Pagrosomus major ) of different body sizes. The total concentrations and subcellular distributions of these trace elements in fish muscles were also determined. Bioaccessibility of these trace elements was generally high (>45%), and the lowest bioaccessibility was observed for Fe. Cooking processes, including boiling, steaming, frying, and grilling, generally decreased the bioaccessibility of these trace elements, especially for Cu and Zn. The influences of frying and grilling were greater than those of boiling and steaming. The relationship of bioaccessibility and total concentration varied with the elements. A positive correlation was found for As and Cu and a negative correlation for Fe, whereas no correlation was found for Cd, Se, and Zn. A significant positive relationship was demonstrated between the bioaccessibility and the elemental partitioning in the heat stable protein fraction and in the trophically available fraction, and a negative correlation was observed between the bioaccessibility and the elemental partitioning in metal-rich granule fraction. Subcellular distribution may thus affect the bioaccessibility of metals and should be considered in the risk assessment for seafood safety.

Acute suppression of serum IgM and IgA in tank workers exposed to benzene.

PubMed

Kirkeleit, J; Ulvestad, E; Riise, T; Bråtveit, M; Moen, B E

2006-12-01

We investigated associations between benzene exposure and alterations of proteins and cells of the immune system among workers maintaining cargo tanks containing crude oil residues. Individual exposure to benzene, benzene in blood and urine, peripheral blood lymphocytes (total lymphocytes, lymphocytes in subpopulations CD3, CD4, CD8, CD19, CD56 and CD4/CD8 ratio), complement factors C3 and C4 and serum concentration of immunoglobulins (IgG, IgA, IgM and IgE) were analysed among 13 tank workers and nine unexposed referents (catering section). Benzene exposure was measured during three consecutive 12-h work days. Blood and urine samples were collected pre-shift on the first day (baseline), post-shift on the third day, and pre-next shift on the following morning. The time spent in the cargo tank was logged. The individual geometric mean benzene exposure in the breathing zone of tank workers over 3 days was 0.15 p.p.m. (range 0.01-0.62 p.p.m.) (n = 26). The geometric mean benzene concentration in blood post-shift was 12.3 nmol/l among tank workers versus 0.7 nmol/l among the referents. Tank workers showed a decline (versus referents) in IgM from baseline to post-shift (t-test, P = 0.04) and IgA from baseline to pre-next shift (t-test, P = 0.01). They also showed a decline in CD4 T cells from baseline to post-shift (t-test, P = 0.04). Suppression correlated with benzene exposure, benzene concentrations in blood and urine and time spent in the tank. The groups did not differ significantly in the change in other immune parameters. The clinical significance is unknown and warrants further studies.

Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA

USGS Publications Warehouse

Balistrieri, L.S.; Seal, R.R.; Piatak, N.M.; Paul, B.

2007-01-01

The authors determine the composition of a river that is impacted by acid-mine drainage, evaluate dominant physical and geochemical processes controlling the composition, and assess dissolved metal speciation and toxicity using a combination of laboratory, field and modeling studies. Values of pH increase from 3.3 to 7.6 and the sum of dissolved base metal (Cd + Co + Cu + Ni + Pb + Zn) concentrations decreases from 6270 to 100 ??g/L in the dynamic mixing and reaction zone that is downstream of the river's confluence with acid-mine drainage. Mixing diagrams and PHREEQC calculations indicate that mixing and dilution affect the concentrations of all dissolved elements in the reach, and are the dominant processes controlling dissolved Ca, K, Li, Mn and SO4 concentrations. Additionally, dissolved Al and Fe concentrations decrease due to mineral precipitation (gibbsite, schwertmannite and ferrihydrite), whereas dissolved concentrations of Cd, Co, Cu, Ni, Pb and Zn decrease due to adsorption onto newly formed Fe precipitates. The uptake of dissolved metals by aquatic organisms is dependent on the aqueous speciation of the metals and kinetics of complexation reactions between metals, ligands and solid surfaces. Dissolved speciation of Cd, Cu, Ni and Zn in the mixing and reaction zone is assessed using the diffusive gradients in thin films (DGT) technique and results of speciation calculations using the Biotic Ligand Model (BLM). Data from open and restricted pore DGT units indicate that almost all dissolved metal species are inorganic and that aqueous labile or DGT available metal concentrations are generally equal to total dissolved concentrations in the mixing zone. Exceptions occur when labile metal concentrations are underestimated due to competition between H+ and metal ions for Chelex-100 binding sites in the DGT units at low pH values. Calculations using the BLM indicate that dissolved Cd and Zn species in the mixing and reaction zone are predominantly inorganic, which is consistent with the DGT results. Although the DGT method indicates that the majority of aqueous Cu species are inorganic, BLM calculations indicate that dissolved Cu is inorganic at pH 5.5. Integrated dissolved labile concentrations of Cd, Cu and Zn in the mixing and reaction zone are compared to calculated acute toxicity concentrations (LC50 values) for fathead minnows (Pimephales promelas) (Cd, Cu and Zn) and water fleas (Ceriodaphnia dubia) (Cd and Cu) using the BLM, and to national recommended water quality criteria [i.e., criteria maximum concentration (CMC) and criterion continuous concentration (CCC)]. Observed labile concentrations of Cd and Zn are below LC50 values and CMC for Cd, but above CCC and CMC for Zn at sites <30 m downstream of the confluence. In contrast, labile Cu concentrations exceed LC50 values for the organisms as well as CCC and CMC at sites <30 m downstream of the confluence. These results suggest that environmental conditions at sites closest to the confluence of the river and acid-mine drainage should not support healthy aquatic organisms. ?? 2007 Elsevier Ltd. All rights reserved.

Pharmacokinetic and pharmacodynamic studies of two different rabbit antithymocyte globulin dosing regimens: results of a randomized trial.

PubMed

Büchler, Matthias; Longuet, Hélène; Lemoine, Roxane; Herr, Florence; Gatault, Philippe; Thibault, Gilles; Ternant, David; Foulon, Christine; Pilorge, Bernadette; Lemay, Djamila; Sung, Crystal; Halimi, Jean-Michel; Baron, Christophe; Lebranchu, Yvon

2013-03-01

Rabbit antithymocyte globulin (rATG; Thymoglobulin(®)) is currently used to prevent acute rejection in kidney transplantation. The dose and regimen of rATG have not been optimized. Moreover, the impact of different treatment regimens on T-cell phenotype reconstitution remains unknown. We conducted a prospective randomized study of 17 renal transplant patients to determine the pharmacokinetics of total and active (bound to human cells) rATG and T-cell phenotype reconstitution after rATG administration. Patients received rATG at a total dose of 6mg/kg, administered either as 1.5mg/kg/day on days 0-3 (Group 1, n=8) or 3mg/kg on days 0 and 3 (Group 2, n=9). All patients received tacrolimus, mycophenolate mofetil and steroids. Blood samples were assayed for total rATG by enzyme linked immunosorbent assay and active rATG by flow cytometry. Maximum concentrations and terminal half-lives were similar between the two groups but at month 3 Group 1 had significantly lower values for total rATG (concentration was 6.2±1.1μg/mL versus 10.2±2.9μg/mL in Group 2, p=0.027) and total rATG dose-normalized AUC (374±83dayg/mL versus 508±149dayg/mL in Group 2, p=0.046). Time to sub-therapeutic levels (<1μg/mL) of active rATG was significantly shorter in Group 1 (18.75±6.9days versus 20±7.5days in Group 2, p<0.001). rATG induced significant depletion followed by slow reconstitution of CD3(+), CD4(+) and CD8(+) cells, with no marked differences between groups. B-cell count was unaffected, whereas CD3(-)CD56(+) NK-cell depletion was observed in both groups. rATG induced a significant decrease in the proportion of naïve CD4(+) T-cells, which plateaued after month 1 in Group 1 and after month 6 in Group 2. The proportion of central memory CD4(+) T-cells increased to a similar extent in both groups (Group 1: 38±18% at baseline, 74±23% at one year, p=0.009; Group 2: 32±14% at baseline, 65±14% at one year, p=0.001). In conclusion, our results suggest that the dosing regimen for rATG induction influences pharmacokinetic parameters without affecting the quality of immune reconstitution. Copyright © 2013 Elsevier B.V. All rights reserved.

Is PM(10) mass measurement a reliable index for air quality assessment? An environmental study in a geographical area of north-eastern Italy.

PubMed

Cozzi, F; Adami, G; Barbieri, P; Reisenhofer, E; Bovenzi, M

2008-09-01

The aim of this study was to measure the concentration of some metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Ti) in PM(10) samples collected in one urban and one industrial site and to assess that PM(10) total mass measurement may be not sufficient as air quality index due to its complex composition. Metals were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and differential pulsed anodic stripping voltammetry (DPASV). The measured concentrations were used to calculate the content of metals in the PM(10) total mass, and to estimate the enrichment factors and the correlations between PM(10), metal concentrations and meteorological data for the two sites. The mean PM10 concentration during the sampling period in the urban site exceeded the annual European Union (EU) standard (40 microg/m(3)) and, for some sampling days, the daily EU standard (50 microg/m(3)) was also exceeded. In opposite, both EU standards were never exceeded in the industrial site. The overall metal content was nearly double in the industrial site compared to the urban one, and the mean Ni concentration exceeded the EU annual limit value (10 ng/m(3)). The metals with the highest enrichment factor were Cd, Cu, Ni and Pb for both sites, suggesting a dominant anthropogenic source for these metals. Metal concentrations were very low and typical of rural background during Christmas holidays, when factories were closed. PM(10) total mass measurement is not a sufficient air quality index since the metal content of PM(10) is not related to its total mass, especially in sites with industrial activities. This measurement should be associated with the analysis of toxic metals.

Radionuclides (210Po and 210Pb) and Some Heavy Metals in Fish and Sediments in Lake Bafa, Turkey, and the Contribution of 210Po to the Radiation Dose.

PubMed

Manav, Ramazan; Uğur Görgün, Aysun; Filizok, Işık

2016-11-09

The pollution level of Lake Bafa was investigated by collecting fish samples { Dicentrarchus labrax (sea bass), Liza ramada (mullet) and Anguilla anguilla (eel)}, surface sediment, and core samples. In all these samples, 210 Po and 210 Pb concentrations were estimated, and total annual dose rates were obtained for each species. Some heavy metal (Cr, Ni, Pb, Cd, Mn, Fe, and Zn) concentration levels were obtained for the fish and a core sample. The sediment mass accumulation rate was found to be 3.27 g·m -2 ·day -1 (0.119 g·cm -2 ·y -1 ) from a core sample. The heavy metal concentrations in the vertical profile of samples from the core were also observed. The measured concentration of Zn, Pb, Cd, and Cr were between the ERL (effects range low) and ERM (effects range median) limits, while Ni concentrations were higher than the ERM limit. The observed concentrations of Cd, Pb, and Zn in fish samples did not exceed the limits in accordance with Turkish Food Regulations. Further, the maximum effective dose equivalent of 210 Po in the area was found to be 1.169 µSv·y -1 .

Soil zinc and cadmium availability and uptake by wheat (Triticum aestivum L.) as affected by long-term organic matter management

NASA Astrophysics Data System (ADS)

Grüter, Roman; Costerousse, Benjamin; Mayer, Jochen; Mäder, Paul; Thonar, Cécile; Frossard, Emmanuel; Schulin, Rainer; Tandy, Susan

2017-04-01

Zinc (Zn) deficiency is a widespread problem in human mineral nutrition. It is mainly caused by imbalanced diets with low contents of bioavailable Zn. This is in particular a problem in populations depending on cereals such as wheat (Triticum aestivum L.) as a major source of this essential micronutrient element. Increasing Zn concentrations in wheat grains (biofortification) is therefore an important challenge. At the same time, increased uptake of the toxic heavy metal cadmium (Cd) must be prevented. Agronomic practises influence soil properties such as pH and soil organic carbon and thus also have an indirect effect on phytoavailable soil Zn and Cd concentrations and the uptake of these metals by wheat in addition to direct inputs with fertilizers and other amendments. This study investigated the effects of long-term organic matter management on the phytoavailability of soil Zn and Cd and their uptake by wheat on plots of two Swiss long-term field trials. In one trial (DOK), a farming system comparison trial established in 1978, we compared plots under conventional management with mineral fertilization either in combination or not with farmyard manure application to plots under biodynamic organic management and control plots with no fertilizer application. In the second trial (ZOFE), established in 1949, we compared different fertilizer regimes on conventionally managed plots, including plots with application of mineral fertilizers only, farmyard manure, or compost and control plots with no fertilizer application. Soil physico-chemical and biological properties were determined at the beginning of the growing season. Soil Zn and Cd availabilities were assessed by the Diffusive Gradients in Thin Films (DGT) method and by DTPA extraction before and after wheat cultivation. Additionally, various wheat yield components and element concentrations in shoots and grains were measured at harvest. In the ZOFE trial, soil Zn and Cd concentrations were lowest in the mineral fertilizer and highest in the farmyard manure treatments, where metal export via crop harvests and inputs through farmyard manure dominated soil metal mass balances in the long-term, respectively. DGT-available Zn and Cd correlated negatively with soil pH, total organic carbon and microbial biomass in both trials. They were lowest in the biodynamic and compost treatments and highest in the control treatments. In the ZOFE trial, wheat yields on mineral fertilized plots exceeded the other treatments by more than a factor of two. Cd concentrations in wheat shoots and grains showed a strong positive correlation with DGT-available soil Cd. They were lowest in biodynamic and compost treatments. In contrast, shoot and grain Zn concentrations correlated more closely with total and DTPA-extractable than with DGT-available soil Zn in the ZOFE trial and they poorly correlated with both Zn availability indicators in the DOK trial. Despite these differences, the study reveals that long-term organic matter management has an important influence on the availability of both elements in soil and their uptake by wheat.

A differential impact of mycophenolic acid, prednisolone, and tacrolimus exposure on sCD30 levels in adult kidney transplant recipients.

PubMed

Barraclough, Katherine A; Staatz, Christine E; Johnson, David W; Gillis, David; Lee, Katie J; McWhinney, Brett C; Ungerer, Jacobus P J; Campbell, Scott B; Isbel, Nicole M

2013-04-01

Soluble CD30 (sCD30) has been associated with rejection and graft loss in kidney transplantation, leading to the suggestion that sCD30 might be a useful biomarker to adjust immunosuppressant medication dosing. However, there has been minimal study of the influence of individual immunosuppressive drugs on sCD30 levels. To evaluate the influence of mycophenolic acid (MPA), prednisolone, and tacrolimus exposure on sCD30 levels in adult kidney transplant recipients. The sCD30 levels were measured pretransplant and 30 days posttransplant. Area under the concentration-time curve (AUC) for each drug was estimated on day 30 using validated, multiple regression-derived limited sampling strategies. One hundred twenty-five subjects were included. Median (interquartile range) sCD30 levels were lower on day 30 posttransplant compared with pretransplant [10.7 (3.7-20.1) pg/mL versus 66.5 (46.0-95.1) pg/mL; P < 0.0001]. On univariate analyses, day 30 sCD30 levels were negatively correlated with MPA exposure and positively correlated with tacrolimus exposure. Using multivariate logistic regression, higher tacrolimus exposure was independently associated with higher day 30 sCD30 levels (2.2 change in odds for an SD increase in tacrolimus AUC 0-12, P = 0.01; 5.5 change in odds for an SD increase in tacrolimus predose concentration, P < 0.0001). In contrast, MPA and total and free prednisolone exposures were not independently associated with sCD30 levels. The sCD30 levels are significantly reduced in the presence of combination immunosuppression but are differentially affected by different immunosuppressant agents. More research is required before introduction of sCD30 measurement into clinical practice can be considered.

Assessment of Welders Exposure to Carcinogen Metals from Manual Metal Arc Welding in Gas Transmission Pipelines, Iran

PubMed Central

Golbabaei, F; Seyedsomea, M; Ghahri, A; Shirkhanloo, H; Khadem, M; Hassani, H; Sadeghi, N; Dinari, B

2012-01-01

Background: Welding can produce dangerous fumes containing various metals especially carcinogenic ones. Occupational exposure to welding fumes is associated with lung cancer. Therefore, welders in Gas Transmission Pipelines are known as a high-risk group. This study was designed to determinate the amounts of metals Cr, Ni, and Cd in breathing zone and urine of welders and to assess the possibility of introducing urinary metals as a biomarker due to occupational exposure. Methods: In this cross sectional study, 94 individuals from Gas Transmission Pipelines welders, Iran, Borujen in 2011 were selected and classified into 3 groups including Welders, Back Welders and Assistances. The sampling procedures were performed according to NIOSH 7300 for total chromium, nickel, and cadmium and NIOSH 7600 for Cr+6. For all participants urine samples were collected during the entire work shift and metals in urine were determined according to NIOSH 8310. Results: Back Welders and Assistances groups had maximum and minimum exposure to total fume and its elements, respectively. In addition, results showed that there are significant differences (P<0.05) between Welders and Back Welders with Assistances group in exposure with total fume and elements except Ni. Urinary concentrations of three metals including Cr, Cd and Ni among all welders were about 4.5, 12 and 14-fold greater than those detected in controls, respectively. Weak correlations were found between airborne and urinary metals concentrations (R2: Cr=0.45, Cd=0.298, Ni=0.362). Conclusion: Urinary metals concentrations could not be considerate as a biomarker for welders’ exposure assessment. PMID:23113226

Assessment of welders exposure to carcinogen metals from manual metal arc welding in gas transmission pipelines, iran.

PubMed

Golbabaei, F; Seyedsomea, M; Ghahri, A; Shirkhanloo, H; Khadem, M; Hassani, H; Sadeghi, N; Dinari, B

2012-01-01

Welding can produce dangerous fumes containing various metals especially carcinogenic ones. Occupational exposure to welding fumes is associated with lung cancer. Therefore, welders in Gas Transmission Pipelines are known as a high-risk group. This study was designed to determinate the amounts of metals Cr, Ni, and Cd in breathing zone and urine of welders and to assess the possibility of introducing urinary metals as a biomarker due to occupational exposure. In this cross sectional study, 94 individuals from Gas Transmission Pipelines welders, Iran, Borujen in 2011 were selected and classified into 3 groups including Welders, Back Welders and Assistances. The sampling procedures were performed according to NIOSH 7300 for total chromium, nickel, and cadmium and NIOSH 7600 for Cr+6. For all participants urine samples were collected during the entire work shift and metals in urine were determined according to NIOSH 8310. Back Welders and Assistances groups had maximum and minimum exposure to total fume and its elements, respectively. In addition, results showed that there are significant differences (P<0.05) between Welders and Back Welders with Assistances group in exposure with total fume and elements except Ni. Urinary concentrations of three metals including Cr, Cd and Ni among all welders were about 4.5, 12 and 14-fold greater than those detected in controls, respectively. Weak correlations were found between airborne and urinary metals concentrations (R2: Cr=0.45, Cd=0.298, Ni=0.362). Urinary metals concentrations could not be considerate as a biomarker for welders' exposure assessment.

Humic acids decrease uptake and distribution of trace metals, but not the growth of radish exposed to cadmium toxicity.

PubMed

Ondrasek, Gabrijel; Rengel, Zed; Romic, Davor

2018-04-30

Naturally-occurring highly-complexed and polymerised organics such as humic acids (HA), due to their large negative charge, play a crucial role in biogeochemistry of trace metals (TM). Toxic (Cd) as well as essential (Zn, Cu, Mn) TM bind strongly to HA, but how these organo-metalic forms influence metal uptake by plants is poorly understood. A solution culture study was conducted to characterize the effects of different concentrations of HA (0-225mg/L) on the growth and element uptake/distribution in roots, shoots and hypocotyls of radish (Raphanus sativus L.) exposed to Cd (0.5mg/L) contamination. After 10-d-exposure to applied treatments, Cd induced phytotoxicity; in contrast, different concentrations of HA had no influence on biomass, but decreased concentration of most TM in examined tissues (Cu by 4.2-fold, Zn by 2.2-fold, Cd by 1.6-fold and Mn by 34%) and their total plant accumulation (Cu by 73%, Cd by 39%, Zn by 29% and Mn by 22%). HA influenced the transport/distribution of TM, decreasing accumulation in roots and increasing their translocation/deposition in shoots, with no effect on TM content in edible hypocotyls. Chemical speciation modelling of the rooting medium confirmed predominance of free metallic forms in the control (no HA) and the pronounced organo-metal complexation in the HA treatments. The results provide evidence of strong capacity of HA to decrease phytoavailability and uptake of Cd, Zn, Cu and Mn while being non-toxic even at relatively high concentration (225mg/L). Thus, HA, as naturally present soil components, control mobility and phyto-extraction of most TM as well as their phyto-accumulation. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of cadmium (Cd) concentration in arable soil in China.

PubMed

Zhang, Xiuying; Chen, Dongmei; Zhong, Taiyang; Zhang, Xiaomin; Cheng, Min; Li, Xinhui

2015-04-01

Cadmium (Cd) concentration in arable soil has drawn broad public attention due to its direct effect on Cd concentration in food. However, there have been few studies of surveying Cd accumulation on the national scale in China. This paper collected 486 studies of Cd concentrations in Chinese arable soil. The results showed that the average Cd concentration was 0.27 mg/kg, higher than its background value, indicating that Cd had been introduced into arable soil by human activity. The Cd concentrations in areas of mining and smelting, urban areas, and areas irrigated by wastewater were obviously higher than that in remote areas. Spatially, Cd concentrations were lower in the north than those in the south, and many hotspots existed throughout China due to mining and smelting activities. Most Cd in the arable soil were accumulated from external sources in all investigated provinces except Ningxia Hui Autonomous Region.

Ecological and human health risk assessment of heavy metal contamination in soil of a municipal solid waste dump in Uyo, Nigeria.

PubMed

Ihedioha, J N; Ukoha, P O; Ekere, N R

2017-06-01

The study assessed the levels of some heavy metals in soils in the vicinity of a municipal solid waste dumpsite with a view to providing information on the extent of contamination, ecological risk of metals in the soils and human health risk to the residents in Uyo. Soil samples were collected in rainy and dry seasons and analyzed for metals (Pb, Cd, Zn, Mn, Cr, Ni and Fe) using atomic absorption spectrometry. The concentrations of heavy metals (mg/kg) at the dumpsite in rainy season were Pb (9.90), Zn (137), Ni (12.56), Cr (3.60), Cd (9.05) and Mn (94.00), while in dry season, the concentrations were Pb (11.80), Zn (146), Ni (11.82), Cr (4.05), Cd (12.20) and Mn (91.20). The concentrations of metals in the studied sites were higher than that of the control site (P < 0.05). Pollution indices studies revealed that soil samples from dumpsite and distances from 10 and 20 m east of the dumpsite were highly polluted with cadmium. Ecological risk assessment carried out showed that cadmium contributed 98-99 % of the total potentially ecological risk. No probable health risk was observed as the total hazard index of all the metals was less than one. However, children were found to be more susceptible to heavy metal contamination than adult.

Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China

PubMed Central

2017-01-01

Background Metal mining and waste discharge lead to regional heavy metal contamination and attract major concern because of the potential risk to local residents. Methods This research was conducted to determine lead (Pb), cadmium (Cd), arsenic (As), manganese (Mn), and antimony (Sb) concentrations in soil and brown rice samples from three heavy metal mining areas in Hunan Province, central China, and to assess the potential health risks to local inhabitants. Results Local soil contamination was observed, with mean concentrations of Cd, Pb, Sb, and As of 0.472, 193.133, 36.793, and 89.029 mg/kg, respectively. Mean concentrations of Cd, Pb, Sb, Mn, and As in brown rice were 0.103, 0.131, 5.175, 6.007, and 0.524 mg/kg, respectively. Daily intakes of Cd, As, Sb, Pb, and Mn through brown rice consumption were estimated to be 0.011, 0.0002, 0.004, 0.0001, and 0.0003 mg/(kg/day), respectively. The combined hazard index for the five heavy metals was 22.5917, and the total cancer risk was 0.1773. Cd contributed most significantly to cancer risk, accounting for approximately 99.77% of this risk. Conclusions The results show that potential noncarcinogenic and carcinogenic health risks exist for local inhabitants and that regular monitoring of pollution to protect human health is urgently required. PMID:29065598

Associations of semen quality with non-essential heavy metals in blood and seminal fluid: data from the Environment and Male Infertility (EMI) study in Lebanon.

PubMed

Sukhn, Carol; Awwad, Johnny; Ghantous, Akram; Zaatari, Ghazi

2018-06-21

Human exposure to environmental pollutants is widespread. It was suggested that exposure to non-essential heavy metals may adversely affect semen development in men. To evaluate associations between non-essential heavy metals in blood and seminal fluid and semen quality parameters in men. Male partners of heterosexual couples were included. The following elements were measured in blood and seminal fluid: lead (Pb), cadmium (Cd), arsenic (As), barium (Ba), mercury (Hg), and uranium (U) using ion-coupled plasma-mass spectrometry. The fertility clinic at the American University of Beirut Medical Center. Semen quality parameters (volume, concentration, total count, progressive motility, viability, and normal morphology). We found that participants with low-quality semen had significantly higher Cd and Ba concentrations in the seminal fluid than participants with normal-quality semen. We also observed significant associations between low sperm viability and higher blood Cd and Ba, as well as higher seminal Pb, Cd, Ba, and U. Furthermore, U concentrations in the seminal fluid were associated with increased odds ratios for below-reference progressive sperm motility and normal morphology. Environmental exposures to Pb, Cd, Ba, and U appear to adversely influence sperm development in men. In non-occupationally exposed men, measurements of heavy metals in the seminal fluid may be more predictive of below-reference sperm quality parameters than in blood.

Levels and speciation of heavy metals in soils of industrial Southern Nigeria.

PubMed

Olajire, A A; Ayodele, E T; Oyedirdan, G O; Oluyemi, E A

2003-06-01

A knowledge of the total content of trace metals is not enough to fully assess the environmental impact of polluted soils. For this reason, the determination of metal species in solution is important to evaluate their behaviour in the environment and their mobilization capacity. Sequential extraction procedure was used to speciate five heavy metals (Cd, Pb, Cu, Ni and Zn) from four contaminated soils of Southern Nigeria into six operationally defined geochemical species: water soluble, enchangeable, carbonates, Fe-Mn oxide, organic and residual. Metal recoveries were within +/- 10% of the independently determined total Cd, Pb, Cu, Ni and Zn concentrations. The highest amount of Cd (avg. 30%) in the nonresidual fractions was found in the exchangeable fraction, while Cu and Zn were significantly associated with the organic fraction. The carbonate fraction contained on average 14, 18.6, 12.6, 13 and 11% and the residual fraction contained on average 47, 18, 33, 50 and 25% of Cd, Pb, Cu, Ni and Zn respectively. Assuming that mobility and bioavailability of these metals are related to the solubility of the geochemical form of the metals, and that they decrease in the order of extraction sequence, the apparent mobility and potential bioavailability for these five metals in the soil were: Pb > Zn > Cu > Ni > Cd. The mobility indexes of copper and nickel correlated positively and significantly with the total content of metals, while mobility indexes of cadmium and zinc correlated negatively and significantly with the total content of metals.

Cadmium phytoavailability to rice (Oryza sativa L.) grown in representative Chinese soils. A model to improve soil environmental quality guidelines for food safety.

PubMed

Rafiq, Muhammad T; Aziz, Rukhsanda; Yang, Xiaoe; Xiao, Wendan; Rafiq, Muhammad K; Ali, Basharat; Li, Tingqiang

2014-05-01

Food chain contamination by cadmium (Cd) is globally a serious health concern resulting in chronic abnormalities. Rice is a major staple food of the majority world population, therefore, it is imperative to understand the relationship between the bioavailability of Cd in soils and its accumulation in rice grain. Objectives of this study were to establish environment quality standards for seven different textured soils based on human dietary toxicity, total Cd content in soils and bioavailable portion of Cd in soil. Cadmium concentrations in polished rice grain were best related to total Cd content in Mollisols and Udic Ferrisols with threshold levels of 0.77 and 0.32mgkg(-1), respectively. Contrastingly, Mehlich-3-extractable Cd thresholds were more suitable for Calcaric Regosols, Stagnic Anthrosols, Ustic Cambosols, Typic Haplustalfs and Periudic Argosols with thresholds values of 0.36, 0.22, 0.17, 0.08 and 0.03mgkg(-1), respectively. Stepwise multiple regression analysis indicated that phytoavailability of Cd to rice grain was strongly correlated with Mehlich-3-extractable Cd and soil pH. The empirical model developed in this study explains the combined effects of soil properties and extractable soil Cd content on the phytoavailability of Cd to polished rice grain. This study indicates that accumulation of Cd in rice is influenced greatly by soil type, which should be considered in assessment of soil safety for Cd contamination in rice. This investigation concluded that the selection of proper soil type for food crop production can help us to avoid the toxicity of Cd in our daily diet. © 2013 Elsevier Inc. All rights reserved.

Biogas production from pretreated coffee-pulp waste by mixture of cow dung and rumen fluid in co-digestion

NASA Astrophysics Data System (ADS)

Juliastuti, Sri Rachmania; Widjaja, Tri; Altway, Ali; Iswanto, Toto

2017-05-01

Coffee is an excellent commodity in Indonesia that has big problem in utilizing its wastes. As the solution, the abundant coffee pulp waste from processing of coffee bean industry has been used as a substrate of biogas production. Coffee pulp waste (CPW) was approximately 48% of total weight, consisting 42% of the coffee pulp and 6% of the seed coat. CPW holds good composition as biogas substrate that is consist of cellulose (63%), hemicellulose (2.3%) and protein (11.5%). Methane production from coffee pulp waste still has much problems because of toxic chemicals content such as caffeine, tannin, and total phenol which can inhibit the biogas production. In this case, CPW was pretreated by ethanol/water (50/50, v/v) at room temperature to remove those inhibitors. This study was to compare the methane production by microbial consortium of cow dung and rumen fluid mixture coffee pulp waste as a substrate with and without pretreatment. The pretreated CPW was fermented with mixture of Cow Dung (CD) and Rumen Fluid (RF) in anaerobic co-digestion for 30 days at mesophilic temperature (30-40°C) and the pH was maintained from 6.8 to 7.2 on a reactor with working volume of 3.6 liters. There were two reactors with each containing the mixture of CPW without pretreatment, cow dung and rumen fluid (CD+RF+CPW) and then compared with the CPW with pretreatment (CD+RF+PCPW) reactor. The measured parameters included the decreasing of inhibitor compound concentration, Volatile Fatty Acids (VFAs), Chemical Oxygen Demand (COD), Total Solid (TS), Volatile Solid (VS), Methane and the Calorific value of gas (heating value) were studied as well. The result showed a decrease in inhibitor component concentration due to methanol pretreatment was 90% of caffeine; 78% of polyphenols (total phenol) and 66% of tannins. The highest methane content in biogas was produced in CD+RF+PCPW digester with concentration amounted of 44.56% with heating value of 27,770 BTU/gal.

Immune responses and ultrastructural changes of hemocytes in freshwater crab Sinopotamon henanense exposed to elevated cadmium.

PubMed

Qin, Qin; Qin, Shengjuan; Wang, Lan; Lei, Wenwen

2012-01-15

Cadmium (Cd) is one of the most toxic heavy metals that can impact immunological parameters in aquatic animals. To investigate the immunotoxicity and ultrastructural changes of hemocytes, specimens of Sinopotamon henanense were exposed to different concentrations of cadmium and the differences in immunologic parameters between Cd exposure groups and control groups were investigated. Total hemocyte count (THC) in Cd-exposure groups were decreased significantly when compared with the control groups, especially in the groups treated with higher Cd concentrations and longer exposure time, while no significant differences were observed in the proportions of the three types of hemocytes. Phenoloxidase (PO) activities were significantly higher in Cd-exposure groups than the control groups. Superoxide dismutase (SOD) activities gradually increased in 7.25 and 14.5 mg L⁻¹ Cd groups, but in other higher Cd groups, they showed first increase and following decrease with the exposure time prolonged. Acid phosphatase (ACP) activities were induced at 48 h, and then decreased, while alkaline phosphatase (AKP) activities increased gradually until 96 h. Electron microscopic results showed that nucleus, mitochondria and rough endoplasm recutulum (rER) of three types of hemocytes were sensitive to acute Cd toxicity. In Cd-exposed groups, chromatin condensation, nucleus deformation and nucleus envelope rupture were noted. Additionally, mitochondrial dilation and rER degranulation were observed in Cd-treated crabs. These results suggested that immune response and organelles of hemocyte of S. henanense were impacted by Cd exposure, and the changes of these immunologic parameters reflect changes in crab immune response capability consequent to Cd exposure. Copyright © 2011 Elsevier B.V. All rights reserved.

Hydroponic phytoremediation of Cd, Cr, Ni, As, and Fe: can Helianthus annuus hyperaccumulate multiple heavy metals?

PubMed

January, Mary C; Cutright, Teresa J; Van Keulen, Harry; Wei, Robert

2008-01-01

Sundance sunflowers were subjected to contaminated solutions containing 3, 4, or 5 heavy metals, with and without EDTA. The sunflowers exhibited a metal uptake preference of Cd=Cr>Ni, Cr>Cd>Ni>As and Fe>As>Cd>Ni>Cr without EDTA and Cr>Cd>Ni, Fe>As>Cd>Cr>Ni with EDTA. As uptake was not affected by other metals, but it decreased Cd and Ni concentration in the stems. The presence of Fe improved the translocation of the other metals regardless of whether EDTA was present. In general, EDTA served as a hindrance to metal uptake. For the experiment with all five heavy metals, EDTA decreased Cd in the roots and stems from 2.11 to 1.36 and from 2.83 to 2.3 2mg g(-1) biomass, respectively. For the same conditions, Ni in the stems decreased from 1.98 to 0.94 mg g(-1) total metal uptake decreased from 14.95 mg to 13.89 mg, and total biomass decreased from 2.38 g to 1.99 g. These results showed an overall negative effect in addition of EDTA. However it is unknown whether the negative effect was due to toxicity posed by EDTA or the breaking of phytochelatin-metal bonds. The most important finding was the ability of Sundance sunflowers to achieve hyperaccumulator status for both As and Cd under all conditions studied. Ni hyperaccumulator status was only achieved in the presence of three metals without EDTA.

Trace elements in two odontocete species (Kogia breviceps and Globicephala macrorhynchus) stranded in New Caledonia (South Pacific).

PubMed

Bustamante, P; Garrigue, C; Breau, L; Caurant, F; Dabin, W; Greaves, J; Dodemont, R

2003-01-01

Liver, muscle and blubber tissues of two short-finned pilot whales (Globicephala macrorhynchus) and two pygmy sperm whales(Kogia breviceps) stranded on the coast of New Caledonia have been analysed for 12 trace elements (Al, Cd, Co, Cr, Cu. Fe, organic and total Hg, Mn, Ni, Se, V, and Zn). Liver was shown to be the most important accumulating organ for Cd, Cu, Fe, Hg, Se, and Zn in both species, G. macrorhynchus having the highest Cd, Hg, Se and Zn levels. In this species, concentrations of total Hg are particularly elevated, reaching up to 1452 microg g(-1) dry wt. Only a very low percentage of the total Hg was organic. In both species,the levels of Hg are directly related to Se in liver. Thus, a molar ratio of Hg:Se close to 1.0 was found for all specimens, except for the youngest K. breviceps. Our results suggest that G. macrorhynchus have a physiology promoting the accumulation of high levels of naturally occurring toxic elements. Furthermore, concentrations of Ni, Cr and Co are close to or below the detection limit in the liver and muscles of all specimens. This suggests that mining activity in New Caledonia, which typically elevates the levels of these contaminants in the marine environment, does not seem to be a significant source of contamination for these pelagic marine mammals.

Cadmium-induced oxidative stress, response of antioxidants and detection of intracellular cadmium in organs of moso bamboo (Phyllostachys pubescens) seedlings.

PubMed

Li, Song; Chen, Junren; Islam, Ejazul; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Yan, Wenbo; Peng, Danli; Liu, Dan

2016-06-01

Moso bamboo (Phyllostachys pubescens (Pradelle) Mazel ex J.Houz.) is recognized as a potential phytoremediation plant due to its huge biomass and high tolerance to environmental stresses. The objectives of this study were to investigate mechanism related to cadmium (Cd) tolerance and to evaluate Cd accumulation capacity of moso bamboo. The results of the pot experiment showed that Cd accumulation by bamboo increased with increasing the Cd levels in soil and the values in stem ranged from 28.51 to 132.13 mg kg(-1). Meanwhile chlorophyll in leaves and total biomass showed a decreasing trend. The bioaccumulation factors (BAF) for roots and stem in all the treatments were more than 1.0 and the translocation factor (TF) ranged from 0.70 to 1.06. In hydroponics experiment, the concentrations of malondialdehyde (MDA) in the leaves were significantly increased in Cd treated plants as compared with control. The activities of superoxide dismutase (SOD) and peroxidase (POD) were enhanced at initial stage and then decreased consistently with the increase of Cd addition. The proline concentrations were also increased due to the presence of Cd, particularly at 25 μM Cd treatment. According to TEM-EDX analysis, the cytoplasm was the main site for accumulation of Cd in moso bamboo. On the basis of overall results, it is suggested that moso bamboo could be successfully used for the remediation of low Cd (no more than 5 mg kg(-1)) contaminated soils. Copyright © 2016. Published by Elsevier Ltd.

Cadmium uptake in above-ground parts of lettuce (Lactuca sativa L.).

PubMed

Tang, Xiwang; Pang, Yan; Ji, Puhui; Gao, Pengcheng; Nguyen, Thanh Hung; Tong, Yan'an

2016-03-01

Because of its high Cd uptake and translocation, lettuce is often used in Cd contamination studies. However, there is a lack of information on Cd accumulation in the above-ground parts of lettuce during the entire growing season. In this study, a field experiment was carried out in a Cd-contaminated area. Above-ground lettuce parts were sampled, and the Cd content was measured using a flame atomic absorption spectrophotometer (AAS). The results showed that the Cd concentration in the above-ground parts of lettuce increased from 2.70 to 3.62mgkg(-1) during the seedling stage, but decreased from 3.62 to 2.40mgkg(-1) during organogenesis and from 2.40 to 1.64mgkg(-1) during bolting. The mean Cd concentration during the seedling stage was significantly higher than that during organogenesis (a=0.05) and bolting (a=0.01). The Cd accumulation in the above-ground parts of an individual lettuce plant could be described by a sigmoidal curve. Cadmium uptake during organogenesis was highest (80% of the total), whereas that during bolting was only 4.34%. This research further reveals that for Rome lettuce: (1) the highest Cd content of above-ground parts occurred at the end of the seedling phase; (2) the best harvest time with respect to Cd phytoaccumulation is at the end of the organogenesis stage; and (3) the organogenesis stage is the most suitable time to enhance phytoaccumulation efficiency by adjusting the root:shoot ratio. Copyright © 2015 Elsevier Inc. All rights reserved.

Interaction effects of metals and salinity on biodegradation of a complex hydrocarbon waste.

PubMed

Amatya, Prasanna L; Hettiaratchi, Joseph Patrick A; Joshi, Ramesh C

2006-02-01

The presence of high levels of salts because of produced brine water disposal at flare pits and the presence of metals at sufficient concentrations to impact microbial activity are of concern to bioremediation of flare pit waste in the upstream oil and gas industry. Two slurry-phase biotreatment experiments based on three-level factorial statistical experimental design were conducted with a flare pit waste. The experiments separately studied the primary effect of cadmium [Cd(II)] and interaction effect between Cd(II) and salinity and the primary effect of zinc [Zn(II)] and interaction effect between Zn(II) and salinity on hydrocarbon biodegradation. The results showed 42-52.5% hydrocarbon removal in slurries spiked with Cd and 47-62.5% in the slurries spiked with Zn. The analysis of variance showed that the primary effects of Cd and Cd-salinity interaction were statistically significant on hydrocarbon degradation. The primary effects of Zn and the Zn-salinity interaction were statistically insignificant, whereas the quadratic effect of Zn was highly significant on hydrocarbon degradation. The study on effects of metallic chloro-complexes showed that the total aqueous concentration of Cd or Zn does not give a reliable indication of overall toxicity to the microbial activity in the presence of high salinity levels.

Salicylic acid improves root antioxidant defense system and total antioxidant capacities of flax subjected to cadmium.

PubMed

Belkadhi, Aïcha; De Haro, Antonio; Soengas, Pilar; Obregon, Sara; Cartea, Maria Elena; Djebali, Wahbi; Chaïbi, Wided

2013-07-01

Cadmium (Cd) disrupts the normal growth and development of plants, depending on their tolerance to this toxic element. The present study was focused on the impacts of exogenous salicylic acid (SA) on the response and regulation of the antioxidant defense system and membrane lipids to 16-day-old flax plantlets under Cd stress. Exposure of flax to high Cd concentrations led to strong inhibition of root growth and enhanced lipid peroxides, membrane permeability, protein oxidation, and hydrogen peroxide (H2O2) production to varying degrees. Concomitantly, activities of the antioxidant enzymes catalase (CAT, EC 1.11.1.6), guaïcol peroxydase (GPX, EC 1.11.1.7), ascorbate peroxydase (APX, EC 1.11.1.11), and superoxide dismutase (SOD, EC 1.15.1.1), and the total antioxidant capacities (2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP)) were significantly altered by Cd. In contrast, exogenous SA greatly reduced the toxic effects of Cd on the root growth, antioxidant system, and membrane lipid content. The Cd-treated plantlets pre-soaked with SA exhibited less lipid and protein oxidation and membrane alteration, as well as a high level of total antioxidant capacities and increased activities of antioxidant enzymes except of CAT. These results may suggest that SA plays an important role in triggering the root antioxidant system, thereby preventing membrane damage as well as the denaturation of its components.

Genotoxic effects of heavy metal cadmium on growth, biochemical, cyto-physiological parameters and detection of DNA polymorphism by RAPD in Capsicum annuum L. – An important spice crop of India

PubMed Central

Aslam, Rumana; Ansari, M.Y.K.; Choudhary, Sana; Bhat, Towseef Mohsin; Jahan, Nusrat

2014-01-01

The present study was designed to investigate the effects of cadmium (Cd) on biochemical, physiological and cytological parameters of Capsicum annuum L. treated with five different concentrations (20, 40, 60, 80 and 100 ppm) of the metal. Shoot–root length, pigment and protein content showed a continuous decrease with increasing Cd concentrations and the maximal decline was observed at the higher concentration. Proline content was found to be increased upto 60 ppm while at higher concentrations it gradually decreased. MDA content and chromosomal aberrations increased as the concentration increased. Additionally Random amplified polymorphic DNA (RAPD) technique was used for the detection of genotoxicity induced by Cd. A total of 184 bands (62 polymorphic and 122 monomorphic) were generated in 5 different concentrations with 10 primers where primer OPA-02 generated the highest percentage of polymorphism (52.63%). Dendrogram showed that control, R1 and R2 showed similar cluster and R4 and R5 grouped with R3 into one cluster, which showed that plants from higher doses showed much difference than the plants selected at mild doses which resemble control at the DNA level. This investigation showed that RAPD marker is a useful tool for evaluation of genetic diversity and relationship among different metal concentrations. PMID:25313282

Total Raltegravir Concentrations in Cerebrospinal Fluid Exceed the 50-Percent Inhibitory Concentration for Wild-Type HIV-1▿

PubMed Central

Croteau, David; Letendre, Scott; Best, Brookie M.; Ellis, Ronald J.; Breidinger, Sheila; Clifford, David; Collier, Ann; Gelman, Benjamin; Marra, Christina; Mbeo, Gilbert; McCutchan, Allen; Morgello, Susan; Simpson, David; Way, Lauren; Vaida, Florin; Ueland, Susan; Capparelli, Edmund; Grant, Igor

2010-01-01

HIV-associated neurocognitive disorders continue to be common. Antiretrovirals that achieve higher concentrations in cerebrospinal fluid (CSF) are associated with better control of HIV and improved cognition. The objective of this study was to measure total raltegravir (RAL) concentrations in CSF and to compare them with matched concentrations in plasma and in vitro inhibitory concentrations. Eighteen subjects with HIV-1 infection were enrolled based on the use of RAL-containing regimens and the availability of CSF and matched plasma samples. RAL was measured in 21 CSF and plasma pairs by liquid chromatography-tandem mass spectrometry, and HIV RNA was detected by reverse transcription-PCR (RT-PCR). RAL concentrations were compared to the 50% inhibitory concentration (IC50) for wild-type HIV-1 (3.2 ng/ml). Volunteers were predominantly middle-aged white men with AIDS and without hepatitis C virus (HCV) coinfection. The median concurrent CD4+ cell count was 276/μl, and 28% of CD4+ cell counts were below 200/μl. HIV RNA was detectable in 38% of plasma specimens and 4% of CSF specimens. RAL was present in all CSF specimens, with a median total concentration of 14.5 ng/ml. The median concentration in plasma was 260.9 ng/ml, with a median CSF-to-plasma ratio of 0.058. Concentrations in CSF correlated with those in with plasma (r2, 0.24; P, 0.02) but not with the postdose sampling time (P, >0.50). RAL concentrations in CSF exceeded the IC50 for wild-type HIV in all specimens by a median of 4.5-fold. RAL is present in CSF and reaches sufficiently high concentrations to inhibit wild-type HIV in all individuals. As a component of effective antiretroviral regimens or as the main antiretroviral, RAL likely contributes to the control of HIV replication in the nervous system. PMID:20876368

Multi-Elements in Source Water (Drinking and Surface Water) within Five Cities from the Semi-Arid and Arid Region, NW China: Occurrence, Spatial Distribution and Risk Assessment

PubMed Central

Wu, Ting; Li, Xiaoping; Yang, Tao; Sun, Xuemeng; Cai, Yue; Ai, Yuwei; Zhao, Yanan; Liu, Dongying; Zhang, Xu; Li, Xiaoyun; Wang, Lijun; Yu, Hongtao

2017-01-01

The purpose of this study was to identify the concentration of multi-elements (MEs) in source water (surface and drinking water) and assess their quality for sustainability. A total of 161 water samples including 88 tap drinking waters (DW) and 73 surface waters (SW) were collected from five cities in Xi’an, Yan’an, Xining, Lanzhou, and Urumqi in northwestern China. Eighteen parameters including pH, electrical conductivity (EC), total organic carbon (TOC) total nitrogen (TN), chemical compositions of anions (F−, Cl−, NO3−, HCO3−, SO42−), cations (NH4+, K+, Na+, Ca2+, Mg2+), and metals (lead (Pb), chromium (Cr), cadmium (Cd), copper (Cu)) were analyzed in the first time at the five cities . The results showed that pH values and concentrations of Cl−, SO42−, Na+, K+, Ca2+, Mg2+ and Cd, Cr, Cu in DW were within the permissible limits of the Chinese Drinking Water Quality Criteria, whereas the concentrations of other ions (F−, NO3−, NH4+ and Pb) exceeded their permissible values. In terms of the SW, the concentrations of F−, Cl−, NO3−, SO42− were over the third range threshold i.e., water suitable for fishing and swimming of the Surface Water Quality Standards in China. The spatial distributions of most MEs in source water are similar, and there was no clear variation for all ions and metals. The metals in DW may be caused by water pipes, faucets and their fittings. The noncarcinogenic risk of metals in DW for local children are in decreasing order Cr > Cd > Pb > Cu. The carcinogenic risk from Cr exposure was at the acceptable level according to threshold of USEPA. Although the comprehensive index of potential ecological assessment of Cr, Cd, Pb and Cu in SW ranked at low risk level and was in the order of Huang River in Xining > Peaceful Canal in Urumqi > Yan River in Yan’an > Yellow River in Lanzhou, their adverse effects to ecology and human health at a low concentration in local semi-arid and arid areas should not be ignored in the long run. PMID:28974043

Multi-Elements in Source Water (Drinking and Surface Water) within Five Cities from the Semi-Arid and Arid Region, NW China: Occurrence, Spatial Distribution and Risk Assessment.

PubMed

Wu, Ting; Li, Xiaoping; Yang, Tao; Sun, Xuemeng; Mielke, Howard W; Cai, Yue; Ai, Yuwei; Zhao, Yanan; Liu, Dongying; Zhang, Xu; Li, Xiaoyun; Wang, Lijun; Yu, Hongtao

2017-10-02

The purpose of this study was to identify the concentration of multi-elements (MEs) in source water (surface and drinking water) and assess their quality for sustainability. A total of 161 water samples including 88 tap drinking waters (DW) and 73 surface waters (SW) were collected from five cities in Xi'an, Yan'an, Xining, Lanzhou, and Urumqi in northwestern China. Eighteen parameters including pH, electrical conductivity (EC), total organic carbon (TOC) total nitrogen (TN), chemical compositions of anions (F - , Cl - , NO₃ - ,HCO₃ - , SO₄ 2- ), cations (NH₄⁺, K⁺, Na⁺, Ca 2+ ,Mg 2+ ), and metals (lead (Pb), chromium (Cr), cadmium (Cd), copper (Cu)) were analyzed in the first time at the five cities . The results showed that pH values and concentrations of Cl - , SO₄ 2- , Na⁺, K⁺, Ca 2+ , Mg 2+ and Cd, Cr, Cu in DW were within the permissible limits of the Chinese Drinking Water Quality Criteria, whereas the concentrations of other ions (F - , NO₃ - , NH₄⁺ and Pb) exceeded their permissible values. In terms of the SW, the concentrations of F - , Cl - , NO₃ - , SO₄ 2- were over the third range threshold i.e., water suitable for fishing and swimming of the Surface Water Quality Standards in China. The spatial distributions of most MEs in source water are similar, and there was no clear variation for all ions and metals. The metals in DW may be caused by water pipes, faucets and their fittings. The noncarcinogenic risk of metals in DW for local children are in decreasing order Cr > Cd > Pb > Cu. The carcinogenic risk from Cr exposure was at the acceptable level according to threshold of USEPA. Although the comprehensive index of potential ecological assessment of Cr, Cd, Pb and Cu in SW ranked at low risk level and was in the order of Huang River in Xining > Peaceful Canal in Urumqi > Yan River in Yan'an > Yellow River in Lanzhou, their adverse effects to ecology and human health at a low concentration in local semi-arid and arid areas should not be ignored in the long run.

Total and cytosolic concentrations of twenty metals/metalloids in the liver of brown trout Salmo trutta (Linnaeus, 1758) from the karstic Croatian river Krka.

PubMed

Dragun, Zrinka; Filipović Marijić, Vlatka; Krasnići, Nesrete; Ivanković, Dušica; Valić, Damir; Žunić, Jakov; Kapetanović, Damir; Smrzlić, Irena Vardić; Redžović, Zuzana; Grgić, Ivana; Erk, Marijana

2018-01-01

Total and cytosolic concentrations of twenty metals/metalloids in the liver of brown trout Salmo trutta (Linnaeus, 1758) were studied in the period from April 2015 to May 2016 at two sampling sites on Croatian river Krka, to establish if river water contamination with metals/metalloids downstream of Knin town has influenced metal bioaccumulation in S. trutta liver. Differences were observed between two sites, with higher concentrations of several elements (Ag, As, Ca, Co, Na, Se, Sr, V) found downstream of Knin town, whereas few others (Cd, Cs, Mo, Tl) were, unexpectedly, increased at the Krka River spring. However, total metal/metalloid concentrations in the liver of S. trutta from both sites of the Krka River were still mainly below previously reported levels for pristine freshwaters worldwide. The analysis of seasonal changes of metal/metalloid concentrations in S. trutta liver and their association with fish sex and size mostly indicated their independence of fish physiology, making them good indicators of water contamination and exposure level. Metal/metalloid concentrations in the metabolically available hepatic cytosolic fractions reported in this study are the first data of that kind for S. trutta liver, and the majority of analyzed elements were present in the cytosol in the quantity higher than 50% of their total concentrations, thus indicating their possible availability for toxic effects. However, the special attention should be directed to As, Cd, Cs, and Tl, which under the conditions of increased exposure tended to accumulate more within the cytosol. Although metal/metalloid concentrations in S. trutta liver were still rather low, monitoring of the Krka River water quality and of the health status of its biota is essential due to a trend of higher metal/metalloid bioaccumulation downstream of Knin town, especially taking into consideration the proximity of National Park Krka and the need for its conservation. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of ABCB1, ABCG2, and CYP3A5 polymorphisms on plasma trough concentrations of apixaban in Japanese patients with atrial fibrillation.

PubMed

Ueshima, Satoshi; Hira, Daiki; Fujii, Ryo; Kimura, Yuuma; Tomitsuka, Chiho; Yamane, Takuya; Tabuchi, Yohei; Ozawa, Tomoya; Itoh, Hideki; Horie, Minoru; Terada, Tomohiro; Katsura, Toshiya

2017-09-01

During anticoagulant therapy, major bleeding is one of the most severe adverse effects. This study aimed to evaluate the relationships between ABCB1, ABCG2, and CYP3A5 polymorphisms and plasma trough concentrations of apixaban, a direct inhibitor of coagulation factor X. A total of 70 plasma concentrations of apixaban from 44 Japanese patients with atrial fibrillation were analyzed. In these analyses, the plasma trough concentration/dose (C/D) ratio of apixaban was used as a pharmacokinetic index and all data were stratified according to the presence of ABCB1 (ABCB1 1236C>T, 2677G>T/A, and 3435C>T), ABCG2 (ABCG2 421C>A), and CYP3A5 (CYP3A5*3) polymorphisms. Influences of various clinical laboratory parameters (age, serum creatinine, estimated glomerular filtration rate, aspartate amino transferase, and alanine amino transferase) on the plasma trough C/D ratio of apixaban were included in analyses. Although no ABCB1 polymorphisms affected the plasma trough C/D ratio of apixaban, the plasma trough C/D ratio of apixaban was significantly higher in patients with the ABCG2 421A/A genotype than in patients with the ABCG2 421C/C genotype (P<0.01). The plasma trough C/D ratio of apixaban in patients with CYP3A5*1/*3 or *3/*3 genotypes was also significantly higher than that in patients with the CYP3A5*1/*1 genotype (P<0.05). Furthermore, the plasma trough C/D ratio of apixaban decreased with increased estimated glomerular filtration rate. These results indicate that ABCG2 421A/A and CYP3A5*3 genotypes and renal function are considered potential factors affecting trough concentrations of apixaban.

Toxic metals in cigarettes and human health risk assessment associated with inhalation exposure.

PubMed

Benson, Nsikak U; Anake, Winifred U; Adedapo, Adebusayo E; Fred-Ahmadu, Omowunmi H; Ayejuyo, Olusegun O

2017-11-08

This study evaluated the concentrations of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn) in 10 branded cigarettes commonly consumed in Nigeria. Chemical sequential extraction method and pseudo-total metal digestion procedure were used for extraction of metals from filler tobacco and filter samples. Samples were analyzed using flame atomic absorption spectrometry (FAAS). The filler tobacco of cigarettes had Cd, Cu, Fe, Mn, Pb, and Zn concentrations in the ranges of 5.90-7.94, 18.26-34.94, 192.61-3494.05, 44.67-297.69, 17.21-74.78, and 47.02-167.31 μg/cigarette, respectively. The minimum and maximum concentrations in the filter samples were 8.67-12.34 μg/g of Cd, 1.77-36.48 μg/g of Cu, 1.83-15.27 μg/g of Fe, 3.82-7.44 μg/g of Mn, 4.09-13.78 μg/g of Pb, and 30.07-46.70 μg/g of Zn. The results of this study showed that the concentrations of heavy metals in the filler tobacco samples were consistently higher than those obtained for the cigarette filters except for Cd. Toxic metals were largely found in the most labile chemical fractions. Moderate to very high risks are found associated with potential exposure to Cd and Pb. The carcinogenic risks posed by Cd and Pb ranged between 1.87E-02 and 2.52E-02, 1.05E-03 and 4.76E-03, respectively, while the non-carcinogenic risk estimates for Cd and Pb were greater than 1.0 (HI > 1). Toxic metals in cigarette may have significant carcinogenic and non-carcinogenic health effects associated with inhalation exposure. Continuous monitoring and regulations of the ingredients of imported and locally produced tobacco products are advocated.

Remediation mechanisms for Cd-contaminated soil using natural sepiolite at the field scale.

PubMed

Yin, Xiuling; Xu, Yingming; Huang, Rong; Huang, Qingqing; Xie, Zhonglei; Cai, Yanming; Liang, Xuefeng

2017-12-13

Remediation of heavy metal polluted agricultural soil is essential for human health and ecological safety and remediation mechanisms at the microscopic level are vital for their large-scale utilization. In this study, natural sepiolite was employed as an immobilization agent for in situ field-scale remediation of Cd-contaminated paddy soil and the remediation mechanisms were investigated in terms of soil chemistry and plant physiology. Natural sepiolite had a significant immobilization effect for bioavailable Cd contents in paddy soil, and consequently could lower the Cd concentrations of brown rice, husk, straw, and roots of rice plants by 54.7-73.7%, 44.0-62.5%, 26.5-67.2%, and 36.7-46.7%, respectively. Regarding soil chemistry, natural sepiolite increased the soil pH values and shifted the zeta potentials of soil particles to be more negative, enhancing the fixation or sorption of Cd on soil particles, and resulted in the reduction of HCl and DTPA extractable Cd concentrations in paddy soil. Natural sepiolite neither enhanced nor inhibited iron plaques on the rice root surface, but did change the chemical environments of Fe and S in rice root. Natural sepiolite improved the activities of antioxidant enzymes and enhanced the total antioxidant capacity to alleviate the stress of Cd. It also promotes the synthesis of GSH and NPT to complete the detoxification. In general, the remediation mechanisms of natural sepiolite for the Cd pollutant in paddy soil could be summarized as the collective effects of soil chemistry and plant physiology.

Metal contamination of home garden soils and cultivated vegetables in the province of Brescia, Italy: implications for human exposure.

PubMed

Ferri, Roberta; Hashim, Dana; Smith, Donald R; Guazzetti, Stefano; Donna, Filippo; Ferretti, Enrica; Curatolo, Michele; Moneta, Caterina; Beone, Gian Maria; Lucchini, Roberto G

2015-06-15

For the past century, ferroalloy industries in Brescia province, Italy produced particulate emissions enriched in manganese (Mn), lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), and aluminum (Al). This study assessed metal concentrations in soil and vegetables of regions with varying ferroalloy industrial activity levels. Home gardens (n=63) were selected in three regions of varying ferroalloy plant activity durations in Brescia province. Total soil metal concentration and extractability were measured by X-Ray Fluorescence (XRF), aqua regia extraction, and modified Community Bureau of Reference (BCR) sequential extraction. Unwashed and washed spinach and turnips cultivated in the same gardens were analyzed for metal concentrations by flame atomic absorption spectrometry. Median soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly higher in home gardens near ferroalloy plants compared to reference home gardens. The BCR method yielded the most mobile soil fraction (the sum of extractable metals in Fractions 1 and 2) and all metal concentrations were higher in ferroalloy plant areas. Unwashed spinach showed higher metal concentrations compared to washed spinach. However, some metals in washed spinach were higher in the reference area likely due to history of agricultural product use. Over 60% of spinach samples exceeded the 2- to 4-fold Commission of European Communities and Codex Alimentarius Commission maximum Pb concentrations, and 10% of the same spinach samples exceeded 2- to 3-fold maximum Cd concentrations set by both organizations. Turnip metal concentrations were below maximum standard reference values. Prolonged industrial emissions increase median metal concentrations and most soluble fractions (BCR F1+F2) in home garden soils near ferroalloy plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal concentrations several-fold above maximum standard references. We recommend thorough washing of vegetables to minimize metal exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

Metal contamination of home gardens soils and cultivated vegetables in the province of Brescia, Italy: Implications for human exposure

PubMed Central

Ferri, Roberta; Hashim, Dana; Smith, Donald R.; Guazzetti, Stefano; Donna, Filippo; Ferretti, Enrica; Curatolo, Michele; Moneta, Caterina; Beone, Gian Maria; Lucchini, Roberto G.

2015-01-01

Background For the past century, ferroalloy industries in Brescia province, Italy produced particulate emissions enriched in manganese (Mn), lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), aluminum (Al). This study assessed metal concentrations in soil and vegetables of regions with varying ferroalloy industrial activity levels. Methods Home gardens (n=63) were selected in three regions of varying ferroalloy plant activity duration in Brescia province. Total soil metal concentration and extractability were measured by X-ray fluorescence (XRF), aqua regia extraction, and modified Community Bureau of Reference (BCR) sequential extraction. Unwashed and washed spinach and turnips cultivated in the same gardens were analyzed for metal concentrations by flame atomic absorption spectrometry. Results Median soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly higher in home gardens near ferroalloy plants compared to reference home gardens. The BCR method yielded the most mobile soil fraction (the sum of extractable metals in Fractions 1 and 2) and all metal concentrations were higher in ferroalloy plant areas. Unwashed spinach showed higher metal concentrations compared to washed spinach. However, some metals in washed spinach were higher in the reference area likely due to history of agricultural product use. Over 60% of spinach samples exceeded the 2- to 4-fold Commission of European Communities and Codex Alimentarius Commission maximum Pb concentrations, and 10% of the same spinach samples exceeded 2- to 3-fold maximum Cd concentrations set by both organizations. Turnip metal concentrations were below maximum standard reference values. Conclusions Prolonged industrial emissions increase median metal concentrations and most soluble fractions (BCR F1+F2) in home garden soils near ferroalloy plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal concentrations several-fold above maximum standard references. We recommend thoroughly washing vegetables to minimize metal exposure. PMID:25777956

Phytoextraction of Pb and Cd from a superfund soil: effects of amendments and croppings.

PubMed

Bricker, T J; Pichtel, J; Brown, H J; Simmons, M

2001-01-01

In a growth chamber, maize (Zea mays) and Indian mustard (Brassica juncea) were grown over two croppings in soil from a Superfund site (PbTotal = 65,200 mg/kg and CdTotal = 52mg/kg). Soil treatments consisted of ethylenediaminetetraacetic acid, sodium citrate and composted sewage sludge, each at two rates (EDTA .05%, EDTA .2%, citrate .05%, citrate .2%, CSS 5% and CSS 10%, respectively). In most cases, the EDTA and citrate treatments were superior in terms of solubilizing soil Pb for root uptake and translocation into above-ground biomass. In the first maize crop, the EDTA .2% treatment resulted in 2,435 and 9,389mg/kg Pb in shoot and root tissues, respectively. The CSS treatments typically resulted in lowest Pb and Cd removal efficiencies. Lead remaining in the soil after two croppings was mainly associated with the carbonate, organic, and residual fractions, which represent the less bioavailable forms. Soil Cd was generally more mobile for plant uptake than soil Pb. The EDTA .2% and citrate treatments were most successful in promoting Cd uptake by both maize and mustard. Although Pb concentrations (mg/kg tissue) were lower for maize than mustard, the former removed more total Pb (0.2 mg per pot, mean over all treatments), compared to mustard (0.03 mg), by virtue of its higher biomass production.

The influence of avian biovectors on mercury speciation in a bog ecosystem.

PubMed

Kickbush, Jocelyn C; Mallory, Mark L; Murimboh, John D; Rand, Jennie; Klapstein, Sara J; Loder, Amanda L; Hill, Nicholas M; O'Driscoll, Nelson J

2018-05-08

Methylmercury (MeHg) is a neurotoxin and endocrine disruptor that bioaccumulates and biomagnifies through trophic levels, resulting in potentially hazardous concentrations. Although wetlands are known hotspots for mercury (Hg) methylation, the effects of avian biovectors on these processes are poorly understood. We examined Hg speciation and distribution in shallow groundwater and surface water from a raised-bog with over 30years of avian biovector (herring gulls Larus argentatus and great black-backed gulls Larus marinus) colonization and guano input. Compared to the reference site, the avian-impacted bog had elevated concentrations of total dissolved organic carbon (TOC), total Hg, MeHg, phosphate (PO 4 3- ), and other trace metals, notably Pb, As, Cd and Ni. Spatial interpolation showed that the densest area of gull nesting was co-located with areas that had the highest concentrations of PO 4 3- , MeHg, As and Cd, but not total mercury (THg), and models suggested that Mn, PO 4 3- , and dissolved TOC were strong predictors of MeHg. Our findings suggest that while these gulls may not be a significant source of Hg, the excess of PO 4 3- (a well recognised component of guano) and the subsequent changes in water chemistry due to avian biovector subsidies may increase net Hg methylation. Copyright © 2018 Elsevier B.V. All rights reserved.

Quantitative Campylobacter spp., antibiotic resistance genes, and veterinary antibiotics in surface and ground water following manure application: Influence of tile drainage control.

PubMed

Frey, Steven K; Topp, Edward; Khan, Izhar U H; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Lapen, David R

2015-11-01

This work investigated chlortetracycline, tylosin, and tetracycline (plus transformation products), and DNA-based quantitative Campylobacter spp. and Campylobacter tetracycline antibiotic resistant genes (tet(O)) in tile drainage, groundwater, and soil before and following a liquid swine manure (LSM) application on clay loam plots under controlled (CD) and free (FD) tile drainage. Chlortetracycline/tetracycline was strongly bound to manure solids while tylosin dominated in the liquid portion of manure. The chlortetracycline transformation product isochlortetracycline was the most persistent analyte in water. Rhodamine WT (RWT) tracer was mixed with manure and monitored in tile and groundwater. RWT and veterinary antibiotic (VA) concentrations were strongly correlated in water which supported the use of RWT as a surrogate tracer. While CD reduced tile discharge and eliminated application-induced VA movement (via tile) to surface water, total VA mass loading to surface water was not affected by CD. At both CD and FD test plots, the biggest 'flush' of VA mass and highest VA concentrations occurred in response to precipitation received 2d after application, which strongly influenced the flow abatement capacity of CD on account of highly elevated water levels in field initiating overflow drainage for CD systems (when water level <0.3m below surface). VA concentrations in tile and groundwater became very low within 10d following application. Both Campylobacter spp. and Campylobacter tet(O) genes were present in groundwater and soil prior to application, and increased thereafter. Unlike the VA compounds, Campylobacter spp. and Campylobacter tet(O) gene loadings in tile drainage were reduced by CD, in relation to FD. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Distribution and chemistry of suspended particles from an active hydrothermal vent site on the Mid-Atlantic Ridge at 26°N

NASA Astrophysics Data System (ADS)

Trocine, Robert P.; Trefry, John H.

1988-04-01

Suspended particles were collected from an area of active hydrothermal venting at the Trans-Atlantic Geotraverse (TAG) Hydrothermal Field on the Mid-Atlantic Ridge and analyzed for Fe, Mn, Cd, Zn, Cu, V, Ni, Cr, Pb, Mg, Ca, Al and Si. Rapid advection of vent-derived precipitates produced a lens with total suspended matter (TSM) loadings of 14-60 μg/l at 200-700 m above the seafloor; TSM concentrations > 60 μg/l were observed only at near-vent sites. The distribution of suspended particles correlated well with increased dissolved Mn concentrations and particulate Fe values near the vent source. Particulate Fe values decreased linearly relative to TSM concentrations as hydrothermal precipitates mixed with background suspended matter. Near-vent precipitates were characterized by up to 35% Fe, 2% Zn, 0.6% Cu and > 100 μg/g Cd. In comparison to Fe, particulate Cd, Zn and Cu values decreased dramatically away from the vent source. This trend supports differential settling and/or dissolution of Cd-, Zn- and Cu-bearing phases. Particulate Mn and Fe values were inversely related with only 50 μg Mn/g in the near-vent particles. At near-vent sites, > 99% of the total Mn was in solution; this fraction decreased to 75-80% at background TSM values. In contrast to Cd, Zn and Cu, particulate V levels show a continuous, linear decrease with particulate Fe values. This trend is explained by adsorption of V on Fe-oxides in the vent plume. Scavenging of Cr, Pb and Mg by hydrothermal precipitates is also suggested by the data. Nickel and Al values were low in near-vent particles at < 100 and < 3 μg/g, respectively. The complementary behavior of dissolved Mn and particulate trace metals provides a useful framework for studying broad aspects of hydrothermal plume processes.

[Transfer characteristics of cadmium in soil-vegetable-insect food chain].

PubMed

Ding, Ping; Zhuang, Ping; Li, Zhi-An; Xia, Han-Ping; Tai, Yi-Ping; Lu, Huan-Ping

2012-11-01

Taking two kinds of vegetables (Brassica rapa and Amaranthus mangostanus) and one insect species (Prodenia litura) as test materials, a greenhouse pot experiment was conducted to study the transfer characteristics of cadmium (Cd) in soil-vegetable-insect food chain and the distribution patters of different Cd chemical forms in the organs of the two vegetables. With the increasing concentration of applied Cd in soil, the biomass of the two vegetables decreased significantly, while the Cd concentration in the vegetables had a significant increase. The Cd concentration in the vegetable organs decreased in the order of stem > root > leaf for A. mangostanus, and of stem > leaf > root for B. rapa. The Cd concentration in P. litura larvae also increased with the increasing concentration of Cd in soil, and the maximum Cd concentration in the P. litura larvae on B. rapa and A. mangostanus was 36.7 and 46.3 mg x kg(-1), respectively. In the feces of the larvae on B. rapa and A. mangostanus, the Cd concentration was up to 190 and 229.8 mg x kg(-1), respectively, suggesting that the most part of Cd absorbed by P. litura larvae was excreted out of their bodies via feces. In the organs of the two vegetables, NaCl-extractable Cd was the dominant Cd form (> 70%), followed by d-H2O- and ethanol-extractable Cd, while the HAc-extractable Cd (insoluble cadmium phosphate), HCl-extractable Cd (insoluble cadmium oxalate), and residual Cd only had a very low concentration. Such a present pattern of different Cd forms in vegetable organs could be conducive to the Cd transfer in the food chain. P. litura could ease Cd poison by excreting large amount of absorbed Cd via feces, and effectively restrict the transfer of Cd to next trophic level. Since B. rapa and A. mangostanus could accumulate large amount of Cd in their biomass, the two vegetables were suggested not to be planted in highly Cd-contaminated soil.

Impact of reactive oxygen species on antioxidant capacity of male reproductive system.

PubMed

Riaz, Muhammad; Mahmood, Zahed; Shahid, Muhammad; Saeed, M Usman Qamar; Tahir, Imtiaz Mahmood; Shah, Sm Ali; Munir, Naveed; El-Ghorab, Ahmed

2016-09-01

The present research work was aimed to study the mutual interaction of reactive oxygen species (ROS) and basal cells antioxidant capacity in the male reproductive system and to further establish the association between selected heavy metals and stress markers. Total oxidant status (TOS) and total antioxidant status (TAS) of serum and seminal plasma were determined by automated photometric methods. The concentrations of Selenium (Se), Lead (Pb), and Cadmium (Cd) were determined by using atomic absorption spectrophotometer. The TOS was increased significantly (P <0.05) in seminal plasma as well as in the serum of the infertile group when compared with the fertile group. On the other hand, the TAS of the infertile group was found to be noticeably decreased (P <0.05) when compared with the TAS of the fertile group. Among the heavy metals, a noticeably lower concentration of Se was detected in the infertile group whereas markedly elevated levels of Cd and Pb were observed in the infertile group compared with the fertile group. Among the infertile group a significant inverse correlation (r = -0.521, P <0.05) was observed between Se and TOS and between Cd and Pb (r = -0.407, P <0.05). Contrarily among the infertile group a considerable positive relationship was established between Se and TAS (r = 0.507, P <0.05). It was concluded that the oxidant stress reduces the antioxidant activity in infertile men by elevating the production of ROS. A lower concentration of Se and elevated levels of Pb and Cd explain the individual's exposure to these heavy metals. The study also revealed that the heavy metal toxicity contributes significantly to male infertility. © The Author(s) 2015.

Contamination and health risks from heavy metals in cultivated soil in Zhangjiakou City of Hebei Province, China.

PubMed

Liang, Qian; Xue, Zhan-Jun; Wang, Fei; Sun, Zhi-Mei; Yang, Zhi-Xin; Liu, Shu-Qing

2015-12-01

A total of 79 topsoil samples (ranging from 0 to 20 cm in depth) were collected from a grape cultivation area of Zhangjiakou City, China. The total concentrations of As, Cd, Hg, Cr, Cu, Mn, Ni, Pb, and Zn in soil samples were determined to evaluate pollution levels and associated health risks in each sample. Pollution levels were calculated using enrichment factors (EF) and geoaccumulation index (I geo). Health risks for adults and children were quantified using hazard indexes (HI) and aggregate carcinogenic risks (ACR). The mean concentrations of measured heavy metals Cd, Hg, and Cu, only in the grape cultivation soil samples, were higher than the background values of heavy metals in Hebei Province. According to principal component analysis (PCA), the anthropogenic activities related to agronomic and fossil fuel combustion practices attributed to higher accumulations of Cd, Hg, and Cu, which have slightly polluted about 10-40% of the sampled soils. However, the HI for all of the heavy metals were lower than 1 (within safe limits), and the ACR of As was in the 10(-6)-10(-4) range (a tolerable level). This suggests the absence of both non-carcinogenic and carcinogenic health risks for adults and children through oral ingestion and dermal absorption exposure pathways in the studied area. It should be also noted that the heightened vulnerability of children to health risks was accounted for higher HI and ACR values. Consequently, heavy metal concentrations (e.g., Cd, Hg, Cu) should be periodically monitored in these soils and improved soil management practices are required to minimize possible impacts on children's health.

A field survey of metal binding to metallothionein and other cytosolic ligands in liver of eels using an on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS).

PubMed

Van Campenhout, Karen; Goenaga Infante, Heidi; Goemans, Geert; Belpaire, Claude; Adams, Freddy; Blust, Ronny; Bervoets, Lieven

2008-05-15

The effect of metal exposure on the accumulation and cytosolic speciation of metals in livers of wild populations of European eel with special emphasis on metallothioneins (MT) was studied. Four sampling sites in Flanders showing different degrees of heavy metal contamination were selected for this purpose. An on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS) was used to study the cytosolic speciation of the metals. The distribution of the metals Cd, Cu, Ni, Pb and Zn among cytosolic fractions displayed strong differences. The cytosolic concentration of Cd, Ni and Pb increased proportionally with the total liver levels. However, the cytosolic concentrations of Cu and Zn only increased above a certain liver tissue threshold level. Cd, Cu and Zn, but not Pb and Ni, were largely associated with the MT pool in correspondence with the environmental exposure and liver tissue concentrations. Most of the Pb and Ni and a considerable fraction of Cu and Zn, but not Cd, were associated to High Molecular Weight (HMW) fractions. The relative importance of the Cu and Zn in the HMW fraction decreased with increasing contamination levels while the MT pool became progressively more important. The close relationship between the cytosolic metal load and the total MT levels or the metals bound on the MT pool indicates that the metals, rather than other stress factors, are the major factor determining MT induction.

Pb, Cu and Cd distribution in five estuary systems of Marche, central Italy.

PubMed

Annibaldi, Anna; Illuminati, Silvia; Truzzi, Cristina; Libani, Giulia; Scarponi, Giuseppe

2015-07-15

Heavy metals are subjected to monitoring in estuarine and marine water by the European Union Water Framework Directive, which requires water body health to be achieved by 2021. This is the first survey of heavy metals content in five estuaries of Marche, a region in central Italy. Results showed that total Pb and Cu concentrations decreased by 70-80%, from 1000-2000 to 100-200 ng L(-1) (Pb) and from 2000-3000 to 500-1000 ng L(-1) (Cu) from river to sea. Cd was consistently 20-40 ng L(-1). Dissolved Pb and Cu concentrations declined by 50% and 70% respectively passing from oligohaline to euhaline water, from 150 to 70 ng L(-1) and from 2000-1000 to 600-400 ng L(-1). Cd decreased slightly from ∼20 to ∼10 ng L(-1). Although such concentrations are in the range allowed by the Water Framework Directive, they far exceed (up to 10×) the ground content ceiling set for 2021. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impacts of Steel-Slag-Based Silicate Fertilizer on Soil Acidity and Silicon Availability and Metals-Immobilization in a Paddy Soil

PubMed Central

Ning, Dongfeng; Liang, Yongchao; Liu, Zhandong; Xiao, Junfu; Duan, Aiwang

2016-01-01

Slag-based silicate fertilizer has been widely used to improve soil silicon- availability and crop productivity. A consecutive early rice-late rice rotation experiment was conducted to test the impacts of steel slag on soil pH, silicon availability, rice growth and metals-immobilization in paddy soil. Our results show that application of slag at a rate above higher or equal to 1 600 mg plant-available SiO2 per kg soil increased soil pH, dry weight of rice straw and grain, plant-available Si concentration and Si concentration in rice shoots compared with the control treatment. No significant accumulation of total cadmium (Cd) and lead (Pb) was noted in soil; rather, the exchangeable fraction of Cd significantly decreased. The cadmium concentrations in rice grains decreased significantly compared with the control treatment. In conclusion, application of steel slag reduced soil acidity, increased plant–availability of silicon, promoted rice growth and inhibited Cd transport to rice grain in the soil-plant system. PMID:27973585

Contamination by ten harmful elements in toys and children's jewelry bought on the North American market.

PubMed

Guney, Mert; Zagury, Gerald J

2013-06-04

Toys and children's jewelry may contain metals to which children can be orally exposed. The objectives of this research were (1) to determine total concentrations (TC's) of As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sb, and Se in toys and jewelry (n = 72) bought on the North American market and compare TC's to regulatory limits, and (2) to estimate oral metal bioavailability in selected items (n = 4) via bioaccessibility testing. For metallic toys and children's jewelry (n = 24) 20 items had TC's exceeding migratable concentration limits (European Union). Seven of seventeen jewelry items did not comply with TC limits in U.S. and Canadian regulations. Samples included articles with very high Cd (37% [w/w]), Pb (65%), and Cu (71%) concentrations. For plastic toys (n = 18), toys with paint or coating (n = 12), and brittle or pliable toys (n = 18), TC's were below the EU migration limits (except in one toy for each category). Bioaccessibility tests showed that a tested jewelry item strongly leached Pb (gastric: 698 μg, intestinal: 705 μg) and some Cd (1.38 and 1.42 μg). Especially in metallic toys and jewelry, contamination by Pb and Cd, and to a lesser extent by Cu, Ni, As, and Sb, still poses an acute problem in North America.

Potential health risks via consumption of six edible shellfish species collected from Piura - Peru.

PubMed

Loaiza, I; De Troch, M; De Boeck, G

2018-05-11

Scallops and their potential predators were collected in Sechura Bay and in front of the Illescas Reserved Zone (north Peru), during El Niño-Southern Oscillation (ENSO) 2016, and analyzed for the metals chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb). This study showed that ~20% of the molluscs exceeded the maximum residual levels (MRLs) for human consumption in inorganic As, while ~30% of the crustaceans did. For Cd, around 10% and 40% of the molluscs and the crustaceans were above the MRLs, respectively. The cephalopod Octopus mimus exhibited As concentrations, but not Cd concentrations, that exceeded the MRLs. Cr, Ni, Cu, Zn and Pb in muscle exhibited generally concentrations below the MRLs. Integrated risk indices were estimated to determine if there is a health risk for consumption. Target hazard quotients (THQs) and total hazard indices (HIs) were mostly < 1, implying no human health risk. Provisional tolerable weekly intake (PTWI) for Cd was exceeded in Bursa ventricosa at Illescas Reserved Zone. Target cancer risks (TRs) for inorganic As were always higher than the threshold (1 × 10 -6 ), therefore an actual cancer risk is present. Copyright © 2018 Elsevier Inc. All rights reserved.

Response of Azospirillum brasilense Cd to sodium chloride stress.

PubMed

Rivarola, V; Castro, S; Mori, G; Jofré, E; Fabra, A; Garnica, R; Balegno, H

1998-04-01

Growth of Azospirillum brasilense Cd in the presence of different NaCl concentrations showed that it tolerates up to 200 mM NaCl in the medium, without appreciable decline in growth rate. At 300 mM NaCl, a decrease of 66% in growth was observed at 24 h of culture. At 48 h of culture, bacteria in the presence of 300 mM NaCl reached the maximum optical density value that was attained at 12 h by control cultures. This investigation was designed to elucidate the effect of saline stress on Azospirillum brasilense Cd and the physiologic mechanism involved in its possible salinity tolerance. For this reason, studies of other osmolytes, as well as of putrescine metabolism and protein patterns were done with bacteria grown with this NaCl concentration in the medium, at 24 and at 48 hours. A. brasilense responded to saline stress elevating the intracellular concentration of glutamate at 24 h, and of K+ at 48 h. Glucan pattern, putrescine metabolism, and total and periplasmic protein patterns of the treated group showed several changes with respect to the control. In spite of the several cellular functions affected by saline stress, the results imply that A. brasilense Cd shows salinity tolerance in these experimental conditions.

Dissolved Concentrations, Sources, and Risk Evaluation of Selected Metals in Surface Water from Mangla Lake, Pakistan

PubMed Central

Saleem, Muhammad; Iqbal, Javed; Shah, Munir H.

2014-01-01

The present study is carried out for the assessment of water quality parameters and selected metals levels in surface water from Mangla Lake, Pakistan. The metal levels (Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn) were determined by flame atomic absorption spectrophotometry. Average levels of Cd, Co, Cr, Ni, and Pb were higher than the allowable concentrations set by national and international agencies. Principal component analysis indicated significant anthropogenic contributions of Cd, Co, Cr, Ni, and Pb in the water reservoir. Noncarcinogenic risk assessment was then evaluated using Hazard Quotient (HQing/derm) and Hazard Index (HIing/derm) following USEPA methodology. For adults and children, Cd, Co, Cr, and Pb (HQing > 1) emerged as the most important pollutants leading to noncarcinogenic concerns via ingestion route, whereas there was no risk via dermal contact of surface water. This study helps in establishing pollutant loading reduction goal and the total maximum daily loads, and consequently contributes to preserve public health and develop water conservation strategy. PMID:24744690

Protective Effect of Aronia Melanocarpa Polyphenols on Cadmium Accumulation in the Body: A Study in a Rat Model of Human Exposure to this Metal.

PubMed

Brzoska, Malgorzata M; Galazyn-Sidorczuk, Malgorzata; Jurczuk, Maria; Tomczyk, Michal

2015-01-01

Recently a growing attention has been paid to the possibility of using biologically active compounds, including polyphenols, for the prevention of unfavourable effects of exposure to xenobiotics. The study was aimed to investigate, in a female rat model, whether consumption of Aronia melanocarpa polyphenols (AMP) under chronic exposure to cadmium (Cd) decreases the gastrointestinal absorption and body burden of this heavy metal. For this purpose, Cd turnover (apparent absorption, retention in the body, concentration in the blood, soft tissues and bone tissue, total pool in internal organs, faecal and urinary excretion) was evaluated in the female Wistar rats who were administered only a 0.1% aqueous extract of AMP (prepared from the powdered extract containing 65.74% of polyphenols) as drinking fluid or/and Cd in diet (1 and 5 mg/kg) for up to 24 months. AMP administration under the low Cd treatment (1 mg/kg diet) had only a very slight protective impact against this metal accumulation in the organism, whereas polyphenols application under moderate exposure (5 mg Cd/kg diet) significantly decreased apparent absorption and retention in the body, and increased urinary concentration of this xenobiotic, resulting in its lower concentration in the blood and lower accumulation in soft tissues (mainly in the liver and kidneys) and bone tissue. Based on the study, it can be concluded that consumption of polyphenol- rich products may prevent Cd absorption from the diet polluted by this metal and its accumulation in the females' body, and thus also prevent its toxic action.

Difficulties in relating Cd concentrations in the predatory insect Chaoborus to those of its prey in nature

USGS Publications Warehouse

Croteau, M.-N.; Hare, L.; Tessier, A.

2003-01-01

Because Chaoborus larvae take up most of their cadmium (Cd) from food, we tested the hypothesis that Cd concentrations in this insect are directly related to those in their planktonic prey. We measured Cd in Chaoborus and in Zooplankton collected from 24 eastern Canadian lakes varying widely in their Cd concentrations. Cd concentrations in the predator were not correlated with those in bulk zooplankton, whether separated into size fractions liable to be eaten by Chaoborus or not. In highly acidic lakes, Cd concentrations in Chaoborus did not respond to increases in zooplankton Cd because of either competition between H and Cd ions at Cd absorption sites in the predator's gut or differences in prey community composition between highly acidic and circumneutral lakes. Relationships between Cd in Chaoborus and in its potential prey were stronger when we used Cd concentrations for specific crustacean taxa in a mechanistic model. We conclude that predictive relationships between metal concentrations in predators and their prey are likely to be strongest if the subset of prey consumed by the predator has been characterized and if this information is used in a bioaccumulation model.

Influence of cadmium on antioxidant capacity and four microelement concentrations in tomato seedlings (Lycopersicon esculentum).

PubMed

Dong, Jing; Wu, Feibo; Zhang, Guoping

2006-09-01

Tomato (Lycopersicon esculentum) seedlings were grown in four cadmium (Cd) levels of 0-10 microM in a hydroponic system to analyze the antioxidative enzymes, Cd concentration in the plants, and the interaction between Cd and four microelements. The results showed that there was a significant increase in malondialdehyde (MDA) concentration, and superoxide dismutase (SOD) and peroxidase (POD) activities in the plants subjected to 1-10 microM Cd. This indicates that Cd stress induces an oxidative stress response in tomato plants, characterized by an accumulation of MDA and increase in activities of SOD and POD. Root, stem and leaf Cd concentrations increased with its exposure Cd level, and the highest Cd concentration occurred in roots, followed by leaves and stems. A concentration- and tissue-dependent response was found in the four microelement concentrations to Cd stress in the tomato leaves, stems and roots. Regression analysis showed that there was a significantly negative correlation between Cd and Mn, implying the antagonistic effect of Cd on Mn absorption and translocation. The correlation between Cd and Zn, Cu and Fe were inconsistent among leaves, stems and roots.

Role of freeze-thaw cycles and chlorpyrifos insecticide use on diffuse Cd loss and sediment accumulation

NASA Astrophysics Data System (ADS)

Wang, Fangli; Ouyang, Wei; Hao, Fanghua; Jiao, Wei; Shan, Yushu; Lin, Chunye

2016-06-01

Freeze-thaw cycles are predicted to increase in cold temperate regions. The potential influence of the interactions of freeze-thaw cycles and agrochemicals on the release of Cd into river water is unknown. In this study, the interactions of freeze-thaw cycles and chlorpyrifos (FC) on Cd mobility in soils were analysed. The spatial variability of soil Cd under long-term intensive tillage in a freeze-thaw agro-system was also identified. The temporal variation of sediment Cd was detected based on analysis of the sediment geochemistry. The results showed that FC increased soil Cd mobility, with an increase of approximately 10% in CaCl2-extractable Cd. The increased mobile fractions of water-soluble and exchangeable Cd originated from the decreased fraction of Fe-Mn-oxide-associated Cd and organic matter-bound Cd. The total Cd content in the surface soil followed the zonally decreasing trend of dry land > paddy land > natural land. The Cd concentrations and sedimentation rates of the sediment core generally increased from 1943 to 2013 due to agricultural exploration and farmland irrigation system construction, indicating an increase of the Cd input flux into water. The results provide valuable information about the soil Cd transport response to the influence of climatic and anthropogenic factors in cold intensive agro-systems.

[Spatial distribution and ecological significance of heavy metals in soils from Chatian mercury mining deposit, western Hunan province].

PubMed

Sun, Hong-Fei; Li, Yong-Hu; Ji, Yan-Fang; Yang, Lin-Sheng; Wang, Wu-Yi

2009-04-15

Ores, waste tailings and slag, together with three typical soil profiles (natural soil profiles far from mine entrance and near mine entrance, soil profile under slag) in Chatian mercury mining deposit (CMD), western Hunan province were sampled and their concentrations of mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), zinc (Zn) were determined by HG-ICP-AES and ICP-MS. Enrichment factor and correlation analysis were taken to investigate the origins, distribution and migration of Hg, as well as other heavy metals in the CMD. The results show that Hg is enriched in the bottom of the soil profile far from mine entrance but accumulated in the surface of soil profiles near mine entrance and under slag. The soil profiles near mine entrance and under slag are both contaminated by Hg, while the latter is contaminated more heavily. In the soil profile under slag, Hg concentration in the surface soil, Hg average concentration in the total profile, and the leaching depth of soil Hg are 640 microg x g(-1), (76.74 +/- 171.71) microg x g(-1), and more than 100 cm, respectively; while 6.5 microg x g(-1), (2.74 +/- 1.90) microg x g(-1), and 40 cm, respectively, are found in the soil profile near mine entrance. Soil in the mercury mine area is also polluted by Cd, As, Pb, Zn besides metallogenic element Hg, among which Cd pollution is relatively heavier than others. The mobility of the studied heavy metals in soil follows the order as Hg > Cd > As > Zn approximately equal to Pb. The leaching depth of the heavy metals is influenced by total concentration in the surface soil and soil physico-chemical parameters. The origins, distribution and migration of heavy metals in soil profile in the mining area are related to primary geological environment, and strongly influenced by human mining activities.

Assessment of marine pollution in Izmir Bay: nutrient, heavy metal and total hydrocarbon concentrations.

PubMed

Kucuksezgin, F; Kontas, A; Altay, O; Uluturhan, E; Darilmaz, E

2006-01-01

Izmir Bay (western Turkey) is one of the great natural bays of the Mediterranean. Izmir is an important industrial and commercial centre and a cultural focal point. The main industries in the region include food processing, oil, soap and paint production, chemical industries, paper and pulp factories, textile industries and metal processing. The mean concentrations showed ranges of 0.01-0.19 and 0.01-10 microM for phosphate, 0.10-1.8 and 0.12-27 microM for nitrate+nitrite, and 0.30-5.8 and 0.43-39 microM for silicate in the outer and middle-inner bays, respectively. The TNO(x)/PO(4) ratio is significantly lower than the Redfield's ratio and nitrogen is the limiting element in the middle-inner bays. Diatoms and dinoflagellates were observed all year around in the bay and are normally nitrogen limited. Metal concentrations ranged between Hg: 0.05-1.3, Cd: 0.005-0.82, Pb: 14-113 and Cr: 29-316 microg g(-1) in the sediments. The results showed significant enrichments during sampling periods from Inner Bay. Outer and middle bays show low levels of heavy metal enrichments except estuary of Gediz River. The concentrations of Hg, Cd and Pb in the outer bay were generally similar to the background levels from the Mediterranean. The levels gradually decreased over the sampling period. Total hydrocarbons concentrations range from 427 to 7800 ng g(-1) of sediments. The highest total hydrocarbon levels were found in the inner bay due to the anthropogenic activities, mainly combustion processes of traffic and industrial activities. The concentrations of heavy metals found in fish varied for Hg: 4.5-520, Cd: 0.10-10 and Pb: 0.10-491 microg kg(-1) in Izmir Bay. There was no significant seasonal variation in metal concentrations. An increase in Hg concentration with increasing length was noted for Mullus barbatus. A person can consume more than 2, 133 and 20 meals per week of fish in human diet would represent the tolerable weekly intake of mercury, cadmium and lead, respectively, in Izmir Bay. Heavy metal levels were lower than the results in fish tissues reported from polluted areas of the Mediterranean Sea.

[Residues and potential ecological risk assessment of metal in sediments from lower reaches and estuary of Pearl River].

PubMed

Xie, Wen-Ping; Wang, Shao-Bing; Zhu, Xin-Ping; Chen, Kun-Ci; Pan, De-Bo; Hong, Xiao-You; Yin, Yi

2012-06-01

In order to investigate the heavy metal concentrations and their potential ecological risks in surface sediments of lower reaches and estuary of Pearl River, 21 bottom sediment samples were collected from lower reaches and estuary of Pearl River. Total contents of Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Pb and Hg in these samples were measured by the inductively coupled plasma mass spectrometry (ICP-MS) and the atomic fluorescence spectrometry (AFS) and using the index of geoaccumulation and the potential ecological risk index to evaluate the pollution degree of heavy metals in the sediments. Results indicated that the concentration of total Fe and total Mn were 41658.73 and 1104.73 mg x kg(-1) respectively and toxic trace metals, such as Cr, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Pb and Hg were 86.62, 18.18, 54.10, 80.20, 543.60, 119.55, 4.28, 10.60, 20.26, 104.58 and 0.520 mg x kg(-1). The descending order of pollution degree of various metals is: Cd > As approximately Zn > Hg > Pb approximately Cu approximately Cr, while the single potential ecological risk followed the order: Cd > Hg > As > Cu > Pb > Zn > Cr. The pollution extent and potential ecological risk of Cd were the most serious among all heavy metals. The distribution pattern of Cd individual potential ecological risk indices is exactly the same as that of general potential ecological risk indices for all heavy metals. Clustering analysis indicates that the sampling stations may be classified into five groups which basically reflected the characteristics of the heavy metal contamination and sedimentation environments along the different river reaches in lower reaches and estuary of Pearl Rive. In general, the serious heavy metal pollution and the high potential ecological risk existed in three river reaches: Chengcun-Shawan, Chengcun-Shundegang and Waihai-Hutiaomen. The pollution degree and potential ecological risk are higher in related river reaches of Beijiang than that in other lower reaches and estuary of Pearl River.

Lead, cadmium and organochlorine pesticide residues in hunted red deer and wild boar from northern Italy.

PubMed

Chiari, Mario; Cortinovis, Cristina; Bertoletti, Marco; Alborali, Loris; Zanoni, Mariagrazia; Ferretti, Enrica; Caloni, Francesca

2015-01-01

The objectives of the present study were to assess heavy metal cadmium (Cd), lead (Pb) and organochlorine pesticide concentrations in tissues of red deer (Cervus elaphus) and wild boar (Sus scrofa) from nine hunting areas and to evaluate related risk factors for the host animal. Over a period of 2 years, a total of 1055 and 210 masseters, 424 and 201 livers, 642 and 152 kidneys were collected from wild boar and red deer, respectively, and concentrations of Cd, Pb and organochlorine pesticides were determined. Comparing the two species, Cd concentration in the kidney (3.72 mg/kg), liver (0.67 mg/kg) and muscle (0.02 mg/kg) of wild boar was found to be significantly higher than in the organs of red deer (1.02 mg/kg in the kidneys, 0.07 mg/kg in the liver and 0.006 mg/kg in muscle). Mean Pb concentrations were found to be similar in both animals, with 0.39, 0.52 and 2.60 mg/kg detected in the wild boar kidney, liver and muscle, respectively, and 0.24, 0.21 and 2.04 mg/kg in the respective organs of the red deer. No difference in concentrations were found based on age class, location of tissue sample or contaminant in the case of wild boar. By contrast, a significantly lower Cd concentration was found in the kidney of the young red deer. The search for organochlorine pesticides in both red deer and wild boar produced negative results with values below the limits of detection. Due to the high levels of renal Cd and muscle Pb detected in wild boar and red deer, further research needs to be carried out in an effort to identify the source of contamination and preserve the health of animals and humans.

Blood cadmium concentrations and environmental exposure sources in newcomer South and East Asian women in the Greater Toronto Area, Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiseman, C.L.S., E-mail: clare.wiseman@utoronto.ca

Background: Immigrant women are often identified as being particularly vulnerable to environmental exposures and health effects. The availability of biomonitoring data on newcomers is limited, thus, presenting a challenge to public health practitioners in the identification of priorities for intervention. Objectives: In fulfillment of data needs, the purpose of this study was to characterize blood concentrations of cadmium (Cd) among newcomer women of reproductive age (19–45 years of age) living in the Greater Toronto Area (GTA), Canada and to assess potential sources of environmental exposures. Methods: A community-based model, engaging peer researchers from the communities of interest, was used formore » recruitment and follow-up purposes. Blood samples were taken from a total of 211 newcomer women from South and East Asia, representing primary, regional origins of immigrants to the GTA, and environmental exposure sources were assessed via telephone survey. Metal concentrations were measured in blood samples (diluted with 0.5% (v/v) ammonium hydroxide and 0.1% (v/v) octylphenol ethoxylate) using a quadrupole ICP-MS. Survey questions addressed a wide range of environmental exposure sources, including dietary and smoking patterns and use of nutritional supplements, herbal products and cosmetics. Results: A geometric mean (GM) blood Cd concentration of 0.39 µg/L (SD:±2.07 µg/L) was determined for study participants (min/max: <0.045 µg /L (LOD)/2.36 µg/L). Several variables including low educational attainment (Relative Ratio (RR) (adjusted)=1.50; 95% CI 1.17–1.91), milk consumption (RR (adjusted)=0.86; 95% CI 0.76–0.97), and use of zinc supplements (RR (adjusted)=0.76; 95% CI 0.64–0.95) were observed to be significantly associated with blood Cd concentrations in the adjusted regression model. The variable domains socioeconomic status (R{sup 2}{sub adj}=0.11) and country of origin (R{sup 2}{sub adj}=0.236) were the strongest predictors of blood Cd. Conclusion: Blood Cd concentrations fell below those generally considered to be of human health concern. However, negative health effects cannot be entirely excluded, especially for those that fall in the upper percentile range of the distribution, given the mounting evidence for negative health outcomes at low environmental exposure concentrations. - Highlights: • Blood Cd and exposure sources were assessed for 211 newcomer women in Toronto. • Blood Cd was slightly elevated compared to that in Canadian-born populations. • SES and country of origin were the strongest predictors of blood Cd. • Intake of essential micronutrients is a likely important modulator of blood Cd. • Identified need for more research on newcomers as a function of country of origin.« less

Changes in metallothionein concentrations in response to variation in natural factors (salinity, sex, weight) and metal contamination in crabs from a metal-rich estuary.

PubMed

Legras; Mouneyrac; Amiard; Amiard-Triquet; Rainbow

2000-04-05

Intermoult male and female crabs Pachygrapsus marmoratus and Carcinus maenas were sampled from three sites between the mouth and 25 km upstream in the Gironde, the most Cd-contaminated estuary in France, in order to study the relative importance of natural factors (salinity, sex, weight) and accumulated metal concentrations on metallothionein (MT) concentrations. In the two species studied, higher metal, total protein and MT concentrations were observed in the hepatopancreas than in the gills. In P. marmoratus, MT concentrations were mainly related to changes in the natural factors even if MT and Zn concentrations were positively correlated in the hepatopancreas whereas in C. maenas, the main relationships were with accumulated metal levels. In the case of the natural factors, the most important ones were weight in gills of both crab species, and salinity changes in both hepatopancreas and gills of P. marmoratus. Cd and Cu concentrations in both organs of the two species were inversely related to salinity. The same observation was found for Zn concentrations in C. maenas but not in P. marmoratus. In the hepatopancreas of both species, the highest total protein concentrations were found in crabs from the site with the highest salinity, whereas there were no such differences in the gills. It seems that changes in MT concentrations are linked more to changes in general protein metabolism than to changes in metal accumulation. Thus it was important to examine the storage of metals in other tissue compartments, particularly the insoluble fraction which includes mineral granules which is known to also contribute to trace metal detoxification in invertebrates. In the gills of the crabs, Zn was present mainly in the insoluble fraction, whereas Cd was nearly equally distributed between soluble and insoluble fractions. In contrast, Cu in the gills and all three metals in the hepatopancreas of both species were mainly cytosolic, but this does not necessarily imply a predominant role for MT since the cytosolic fraction also includes other macromolecules which may be the target binding site for accumulated trace metals.

Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d'Alene River, Idaho: Comparisons among chemical equilibrium models and implications for biotic ligand models

USGS Publications Warehouse

Balistrieri, L.S.; Blank, R.G.

2008-01-01

In order to evaluate thermodynamic speciation calculations inherent in biotic ligand models, the speciation of dissolved Cd, Cu, Pb, and Zn in aquatic systems influenced by historical mining activities is examined using equilibrium computer models and the diffusive gradients in thin films (DGT) technique. Several metal/organic-matter complexation models, including WHAM VI, NICA-Donnan, and Stockholm Humic model (SHM), are used in combination with inorganic speciation models to calculate the thermodynamic speciation of dissolved metals and concentrations of metal associated with biotic ligands (e.g., fish gills). Maximum dynamic metal concentrations, determined from total dissolved metal concentrations and thermodynamic speciation calculations, are compared with labile metal concentrations measured by DGT to assess which metal/organic-matter complexation model best describes metal speciation and, thereby, biotic ligand speciation, in the studied systems. Results indicate that the choice of model that defines metal/organic-matter interactions does not affect calculated concentrations of Cd and Zn associated with biotic ligands for geochemical conditions in the study area, whereas concentrations of Cu and Pb associated with biotic ligands depend on whether the speciation calculations use WHAM VI, NICA-Donnan, or SHM. Agreement between labile metal concentrations and dynamic metal concentrations occurs when WHAM VI is used to calculate Cu speciation and SHM is used to calculate Pb speciation. Additional work in systems that contain wide ranges in concentrations of multiple metals should incorporate analytical speciation methods, such as DGT, to constrain the speciation component of biotic ligand models. ?? 2008 Elsevier Ltd.

Metal contamination of soils and crops affected by the Chenzhou lead/zinc mine spill (Hunan, China).

PubMed

Liu, Hongyu; Probst, Anne; Liao, Bohan

2005-03-01

In 1985, the collapse of the tailing dam in Chenzhou lead/zinc mine (Hunan, southern China) led to the spread of mining waste spills on the farmland along the Dong River. After the accident, an urgent soil cleaning up was carried out in some places. Seventeen years later, cereal (rice, maize, and sorghum), pulses (soybean, Adzuki bean, mung bean and peanut), vegetables (ipomoea, capsicum, taro and string bean) and the rooted soils were sampled at four sites: (1) the mining area (SZY), (2) the area still covered with the mining tailing spills (GYB), (3) the cleaned area from mining tailing spills (JTC), and (4) a background site (REF). Metal concentrations in the crops and soils were analyzed to evaluate the long-term effects of the spilled waste on the soil and the potential human exposure through food chains. The results showed that the physical-chemical properties of the soils obviously changed due to the different farming styles used by each individual farmer. Leaching effects and plant extraction of metals from some soils were quite weak. Certain soils were still heavily polluted with As, Cd, Zn, Pb and Cu. The contamination levels were in the order of GYB>SZY>JTC showing that the clean-up treatment was effective. The maximum allowable concentration (MAC) levels for Chinese agricultural soils were still highly exceeded, particularly for As and Cd (followed by Zn, Pb and Cu), with mean concentrations of 709 and 7.6 mg kg(-1), respectively. These concentrations exceed the MAC levels by 24 times for As and 13 times for Cd at GYB. Generally, the edible leaves or stems of crops were more heavily contaminated than seeds or fruits. Ipomoea was the most severely contaminated crop. The concentrations of Cd and Pb were 3.30 and 76.9 mg kg(-1) in ipomoea leaves at GYB, which exceeded the maximum permit levels (0.5 mg kg(-1) for Cd and 9 mg kg(-1) for Pb) by 6.6 and 8.5 times, respectively. Taro (+skin) could accumulate high concentrations of Zn and Cd in the edible stem, and rice and capsicum had high Cd concentration in the edible parts. However, the toxic element concentrations in maize, sorghum, Adzuki bean, soybean and mung bean remained lower than the threshold levels. The bio-accumulation factors (BAFs) of crops were in the order: Cd>Zn>Cu>Pb>As. BAF was typically lower in the edible seeds or fruits than in stems and leaves. The accumulation effect strongly depends on the crop's physiological properties, the mobility, of the metals, and the availability of metals in soils but not entirely on the total element concentrations in the soils. Even so, the estimated daily intake amount of Cu, Zn, Cd, and Pb from the crops grown in the affected three sites and arsenic at SZY and GYB exceeded the RDA (Recommended dietary allowance) levels. Subsequently, the crops grown in Chenzhou Pb/Zn mine waste affected area might have a hazardous effect on the consumer's health. This area still needs effective measures to cure the As, Cd, Pb, Zn and Cu contamination.

Is vetiver grass of interest for the remediation of Cu and Cd to protect marketing gardens in Burkina Faso?

PubMed

Ondo Zue Abaga, Norbert; Dousset, Sylvie; Mbengue, Saliou; Munier-Lamy, Colette

2014-10-01

In Burkina-Faso, urban vegetable agriculture is often characterized by urban solid waste fertilizer inputs containing heavy metals such as Cu and Cd. Thus, the relevance of surrounding urban vegetable plots with vetiver hedges to reduce environmental pollution by Cu and Cd was investigated by adsorption studies and pot experiments. Vetiver biomass, its metal contents and, its total and MgCl2 extractable soil metals were monitored over 6months in the presence of a mixture of metal at two concentrations: 2-10 and 100-500mgkg(-1), for Cd and Cu, respectively. The Freundlich adsorption coefficient (Kf) values increased after vetiver growth and were significantly higher for vertisol than for lixisol. After 6months, the vetiver that was grown on lixisol accumulated more metal, increasing up to 4635mgkg(-1) for Cu and to 21.8mgkg(-1) for Cd, than did the vetiver that was grown on vertisol, increasing up to 1534mgkg(-1) for Cu and to 7.2mgkg(-1) for Cd. The metal bioconcentration factor, which was significantly higher for Cd, increased with the applied concentration and ranged from 1.6 to 14 for Cu and from 2.3 to 22 for Cd. Additionally, the translocation factors were higher for Cd (0.38-7.3) than for Cu (0.07-2.6), and the translocation was easiest from lixisol than from vertisol. Thus our results demonstrate the ability of vetiver for Cu and Cd phytoremediation in Burkina Faso soils. Nevertheless, these results should be confirmed across the field to advocate the establishment of vetiver hedges. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chlordecone, a mixed pregnane X receptor (PXR) and estrogen receptor alpha (ERα) agonist, alters cholesterol homeostasis and lipoprotein metabolism in C57BL/6 mice

PubMed Central

Lee, Junga; Scheri, Richard C.; Zhang, Yuan; Curtis, Lawrence R.

2008-01-01

Chlordecone (CD) is one of many banned organochlorine (OC) insecticides that are widespread persistent organic pollutants. OC insecticides alter lipid homeostasis in rodents at doses that are not neurotoxic or carcinogenic. Pretreatment of mice or rats with CD altered tissue distribution of a subsequent dose of [14C]CD or [14C]cholesterol (CH). Nuclear receptors regulate expression of genes important in the homeostasis of CH and other lipids. In this study, we report that CD suppresses in vitro reporter systems for human liver X receptors (LXRs) and activates those for human farnesoid X receptor (FXR), pregnane X receptor (PXR) and estrogen receptor α (ERα) in a concentration-dependent manner (0–50 μM). Consistent with human PXR activation in vitro, three days after a single dose of CD (15 mg/kg) hepatic microsomal CYP3A11 protein increases in C57BL/6 mice. CD decreases hepatic CH ester content without altering total CH concentration. Apolipoprotein A-I (apoA-I) contents of hepatic lipoprotein-rich and microsomal fractions of CD-treated mice are higher than controls. There is a significant reduction in non-high density lipoprotein CH but not apolipoprotein B-48/100 (apoB-48/100) in plasma from CD-treated mice after a 4 h fast. At 14 days after 15 mg CD/kg apoA-I and apoB-100 proteins but not CYP3A11 protein in hepatic microsomes are similar to controls. This work indicates that altered CH homeostasis is a mode of OC insecticide action of relevance after a single dose. This at least partially explains altered CH tissue distribution in CD-pretreated mice. PMID:18789348

The brown seaweed Sargassum cymosum: changes in metabolism and cellular organization after long-term exposure to cadmium.

PubMed

Costa, Giulia B; Simioni, Carmen; Pereira, Débora T; Ramlov, Fernanda; Maraschin, Marcelo; Chow, Fungyi; Horta, Paulo A; Bouzon, Zenilda L; Schmidt, Éder C

2017-03-01

Sargassum cymosum was exposed to cadmium (Cd) to determine any physiological and ultrastructural effects. To accomplish this, S. cymosum samples were cultivated under photosynthetic active radiation (PAR) and Cd (0, 0.1, 0.2, 0.4 and 0.8 mg L -1 ) during 7 and 14 days in laboratory-controlled conditions (0 mg L -1 Cd at both exposure times as control). Seaweeds had high retention capacity (over 90 %) for both exposure times. Growth rates showed significant increases by 14 days, especially for 0.1 and 0.4 mg L -1 Cd. Photosynthetic parameters were unaffected by Cd treatments. Chlorophyll contents were present in higher concentrations for all Cd treatments compared to respective control. Carotenoid profile showed significant differences in total composition and proportion of fucoxanthin and β-carotene, and no lutein was detected at 14 days. Phenolic and flavonoid compounds showed major accumulation at 14 days. Transmission electron microscopy (TEM) analyses presented major alterations in Cd-treated samples, when compared with respective control, in particular disorganization of cell wall fibrils. When compared to respective control samples, multivariate analyses showed disparate and complex interactions among metabolites in Cd-exposed seaweeds, giving evidence of physiological defence response. Thus, it can be concluded that Cd is a stressor for S. cymosum, resulting in physiological and structural alterations related to defence mechanisms against oxidative stress and toxicological effects resulting from long-term metal exposure. However, in the present paper, some observed changes also appear to result from acclimation mechanisms under lower concentration of Cd relative to the tolerance of S. cymosum to experimental conditions.

A randomized controlled crossover trial of the effect of ginseng consumption on the immune response to moderate exercise in healthy sedentary men.

PubMed

Biondo, Patricia D; Robbins, Sarah J; Walsh, Jennifer D; McCargar, Linda J; Harber, Vicki J; Field, Catherine J

2008-10-01

Ginseng is a popular herbal remedy that is reputed to increase resistance to stress and improve immune function. Regular exercise results in acute physiologic stress that affects the immune response. This study was conducted to investigate the effects of daily consumption of a standardized ginsenoside-containing North American ginseng (Panax quinquefolius) extract on immune function before, during, and after a moderate-exercise protocol in healthy sedentary men. Ten healthy males were randomized to receive either ginseng (1125 mg.d-1) or placebo for 35 days. After a 3 month washout period, subjects received the opposite treatment for another 35 days. An exercise test and blood collection were performed at the end of each treatment period. Immune parameters and blood hormone levels were measured before, during, and after the exercise stress protocol. Ginseng treatment reduced the peripheral blood concentration of CD8+ T cells and increased mitogen-stimulated T cell production of interleukin-2 ex vivo. Ginseng had no effect on total white blood cell counts; on concentrations of neutrophils, monocytes, or lymphocytes (CD3+, CD4+, CD16+, CD20+); on lymphocyte proliferation; or on neutrophil oxidative burst. Ginseng did not significantly affect exercise-induced changes in plasma concentrations of lactate, insulin, cortisol, or growth hormone. The consumption of ginseng for 5 weeks had a limited effect on the immune response to an acute exercise protocol.

Spatial Distribution, Sources Apportionment and Health Risk of Metals in Topsoil in Beijing, China.

PubMed

Sun, Chunyuan; Zhao, Wenji; Zhang, Qianzhong; Yu, Xue; Zheng, Xiaoxia; Zhao, Jiayin; Lv, Ming

2016-07-20

In order to acquire the pollution feature and regularities of distribution of metals in the topsoil within the sixth ring road in Beijing, a total of 46 soil samples were collected, and the concentrations of twelve elements (Nickel, Ni, Lithium, Li, Vanadium, V, Cobalt, Co, Barium, Ba, Strontium, Sr, Chrome, Cr, Molybdenum, Mo, Copper, Cu, Cadmium, Cd, Zinc, Zn, Lead, Pb) were analyzed. Geostatistics and multivariate statistics were conducted to identify spatial distribution characteristics and sources. In addition, the health risk of the analyzed heavy metals to humans (adult) was evaluated by an U.S. Environmental Protection Agency health risk assessment model. The results indicate that these metals have notable variation in spatial scale. The concentration of Cr was high in the west and low in the east, while that of Mo was high in the north and low in the south. High concentrations of Cu, Cd, Zn, and Pb were found in the central part of the city. The average enrichment degree of Cd is 5.94, reaching the standard of significant enrichment. The accumulation of Cr, Mo, Cu, Cd, Zn, and Pb is influenced by anthropogenic activity, including vehicle exhaustion, coal burning, and industrial processes. Health risk assessment shows that both non-carcinogenic and carcinogenic risks of selected heavy metals are within the safety standard and the rank of the carcinogenic risk of the four heavy metals is Cr > Co > Ni > Cd.

Spatial Distribution, Sources Apportionment and Health Risk of Metals in Topsoil in Beijing, China

PubMed Central

Sun, Chunyuan; Zhao, Wenji; Zhang, Qianzhong; Yu, Xue; Zheng, Xiaoxia; Zhao, Jiayin; Lv, Ming

2016-01-01

In order to acquire the pollution feature and regularities of distribution of metals in the topsoil within the sixth ring road in Beijing, a total of 46 soil samples were collected, and the concentrations of twelve elements (Nickel, Ni, Lithium, Li, Vanadium, V, Cobalt, Co, Barium, Ba, Strontium, Sr, Chrome, Cr, Molybdenum, Mo, Copper, Cu, Cadmium, Cd, Zinc, Zn, Lead, Pb) were analyzed. Geostatistics and multivariate statistics were conducted to identify spatial distribution characteristics and sources. In addition, the health risk of the analyzed heavy metals to humans (adult) was evaluated by an U.S. Environmental Protection Agency health risk assessment model. The results indicate that these metals have notable variation in spatial scale. The concentration of Cr was high in the west and low in the east, while that of Mo was high in the north and low in the south. High concentrations of Cu, Cd, Zn, and Pb were found in the central part of the city. The average enrichment degree of Cd is 5.94, reaching the standard of significant enrichment. The accumulation of Cr, Mo, Cu, Cd, Zn, and Pb is influenced by anthropogenic activity, including vehicle exhaustion, coal burning, and industrial processes. Health risk assessment shows that both non-carcinogenic and carcinogenic risks of selected heavy metals are within the safety standard and the rank of the carcinogenic risk of the four heavy metals is Cr > Co > Ni > Cd. PMID:27447657

Effects of cadmium on bioaccumulation and biochemical stress response in rice (Oryza sativa L.).

PubMed

Xie, Pan-pan; Deng, Juan-wei; Zhang, Hui-min; Ma, You-hua; Cao, De-ju; Ma, Ru-xiao; Liu, Ren-jing; Liu, Cheng; Liang, Yue-gan

2015-12-01

This study investigated the effects of various Cd concentrations on the bioaccumulation, antioxidative defense, and stress responses of rice (Oryza sativa L.). The distribution characteristics of Cd in rice were in the following order: roots>stems>grains. The bioconcentration factor values of Cd increased at concentrations lower than 3.00 mg Cd/kg and approximately decreased to a constant value at concentrations higher than 3.00 mg Cd/kg. Rice showed a higher Cd accumulation potential at low Cd concentrations than at high Cd concentrations. The Freundlich isotherm model described well the adsorption isotherms of Cd in rice roots. The biosorption mechanism of rice roots was determined to be cooperative adsorption. The malondialdehyde (MDA) content increased at a concentration range of 0.00-5.00 mg/L, indicating the enhancement of lipid peroxidation. By contrast, the MDA content slightly decreased at concentrations higher than 5.00 mg/L. Peroxidase (POD) activity exhibited active response to oxidative stress at concentrations lower than 5.00 mg/L but was inhibited at concentrations higher than 5.00 mg/L. The response to Cd stress of the N-H, O-H and C-O functional groups in rice shoots was observed via Fourier transform infrared spectroscopy. Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical speciation and risk assessment of cadmium in soils around a typical coal mining area of China.

PubMed

Cheng, Siwei; Liu, Guijian; Zhou, Chuncai; Sun, Ruoyu

2018-05-21

The distribution characteristics of Cadmium (Cd) fractions in soils around a coal mining area of Huaibei coalfield were investigated, with the aim to assess its ecological risk. The total Cd concentrations in soils ranged from 0.05 to 0.87 mg/kg. The high percentage of phyto-available Cd (58%) when redox or base-acid equilibria changed. Soil pH was found to be a crucial factor affecting soil Cd fraction, and carbonate-bound Cd can be significantly affected by both organic matter and pH of soils. The static ecological evaluation models, including potential ecological risk index (PERI), geo-accumulation index (I geo ) and risk assessment code (RAC), revealed a moderate soil Cd contamination and prensented high Cd exposure risk in studied soils. However, the dynamic evaluation of Cd risk, determined using a delayed geochemical hazard (DGH), suggested that our studied soils can be classified as median-risk with a mean probability of 24.79% for Cd DGH. These results provide a better assessment for the risk development of Cd contamination in coal mining areas. Copyright © 2018 Elsevier Inc. All rights reserved.

Health risk assessment of potentially harmful elements and dietary minerals from vegetables irrigated with untreated wastewater, Pakistan.

PubMed

Zia, Munir H; Watts, Michael J; Niaz, Abid; Middleton, Daniel R S; Kim, Alexander W

2017-08-01

In the developing world, vegetables are commonly grown in suburban areas irrigated with untreated wastewater containing potentially harmful elements (PHEs). In Pakistan, there is no published work on the bioaccessibility aspect of PHEs and dietary minerals (DMs) in sewage-irrigated soil or the vegetables grown on such soils in Pakistan. Several industrial districts of Pakistan were selected for assessment of the risk associated with the ingestion of vegetables grown over sewage-irrigated soils. Both the total and bioaccessible fraction of PHEs (Cd, Co, Cr, Ni, and Pb) and DMs (Fe, Cu, Mn, Zn, Ca, Mg, and I) in soils and vegetable samples were measured. The concentrations of these PHEs and DMs in sewage-irrigated and control soils were below published upper threshold limits. However, compared to control soils, sewage irrigation over the years decreased soil pH (7.7 vs 8.1) and enhanced dissolved organic carbon (1.8 vs 0.8 %), which could enhance the phyto-availability of PHEs and DMs to crops. Of the PHEs and DMs, the highest transfer factor (soil to plant) was noted for Cd and Ca, respectively. Concentrations of PHEs in most of the sewage-irrigated vegetables were below the published upper threshold limits, except for Cd in the fruiting portion of eggplant and bell pepper (0.06-0.08 mg/kg Cd, dry weight) at three locations in Gujarat and Kasur districts. The bioaccessible fraction of PHEs can reduce the context of dietary intake measurements compared to total concentrations, but differences between both measurements were not significant for Cd. Since the soils of the sampled districts are not overly contaminated compared to control sites, vegetables grown over sewage-irrigated soils would provide an opportunity to harvest mineral-rich vegetables potentially providing consumers 62, 60, 12, 104, and 63 % higher dietary intake of Cu, Mn, Zn, Ca, and Mg, respectively. Based on Fe and vanadium correlations in vegetables, it is inferred that a significant proportion of total dietary Fe intake could be contributed by soil particles adhered to the consumable portion of vegetables. Faecal sterol ratios were used to identify and distinguish the source of faecal contamination in soils from Gujranwala, Gujarat, and Lahore districts, confirming the presence of human-derived sewage biomarkers at different stages of environmental alteration. A strong correlation of some metals with soil organic matter concentration was observed, but none with sewage biomarkers.

Dissolved heavy metal concentrations of the Kralkızı, Dicle and Batman dam reservoirs in the Tigris River basin, Turkey.

PubMed

Varol, Memet

2013-10-01

Water samples were collected at monthly intervals during 1 year of monitoring from Kralkızı, Dicle and Batman dam reservoirs in the Tigris River basin to assess the concentrations of dissolved heavy metals and to determine their spatial and seasonal variations. The results indicated that dissolved heavy metal concentrations in the reservoirs were very low, reflecting the natural background levels. The lowest total metal concentrations in the three dam reservoirs were detected at sampling sites close to the dam wall. However, the highest total concentrations were observed at sites, which are located at the entrance of the streams to the reservoirs. Fe, Cr and Ni were the most abundant elements in the reservoirs, whereas Cd and As were the less abundant. The mean concentrations of dissolved metals in the dam reservoirs never exceeded the maximum permitted concentrations established by EC (European Community), WHO and USEPA drinking water quality guidelines. All heavy metals showed significant seasonal variations. As, Cd, Cr, Cu, Fe, Ni and Pb displayed higher values in the dry season, while higher values for Zn in the wet season. Cluster analysis grouped all ten sampling sites into three clusters. Clusters 1 and 2, and cluster 3 corresponded to relatively low polluted and moderate polluted regions, respectively. PCA/FA demonstrated the dissolved metals in the dam reservoirs controlled by natural sources. Copyright © 2013 Elsevier Ltd. All rights reserved.

Regional geochemistry of metal-contaminated surficial sediments and seagrasses in upper Spencer Gulf, South Australia

NASA Astrophysics Data System (ADS)

Tiller, K. G.; Merry, R. H.; Zarcinas, B. A.; Ward, T. J.

1989-05-01

Surficial sediments, shallow sediment cores and seagrass samples were collected over an area of about 600 km 2 of upper Spencer Gulf, South Australia, adjacent to a major lead-zinc smelter. Regional variation in heavy metal contents was studied in relation to different pathways of contamination from the smelter complex, and geochemical association with natural constituents of the sediments. About 300 km 2 were contaminated to some extent. Areas of appreciable contamination (10 × background) were greatest for Cd and least for As, with Pb and Zn intermediate. Regional trends of heavy metals in the sediment reflected inputs of pollutants from both liquid effluents and atmospheric fallout, modified by tidal currents. Total accessions to Germein Bay were estimated to be at least 25 000 tonnes each of Pb and Zn and 500 tonnes of Cd and As. Arsenic differed both in its distribution with sediment depth and in its geochemical associations when compared to Pb, Zn and Cd. Correlation of Cd with the fine fraction (< 20 μm) permitted a normalization of data which accounted for marked regional variations in sediment grain size and provided a better basis of assessing the regional impact of pollution. Metal concentrations in Posidonia leaves were highly correlated with total and EDTA extractable metal concentrations in the sediments, and may provide a more sensitive indicator of metal dispersion. Background levels of metals in Posidonia were not found in our study area.

Arsenic Speciation and Cadmium Determination in Tobacco Leaves, Ash and Smoke.

PubMed

Iwai, Takahiro; Chiba, Koichi; Narukawa, Tomohiro

2016-01-01

The concentrations of arsenic (As) and cadmium (Cd) in the tobacco leaves, ash and smoke of 10 kinds of cigarettes collected from different countries worldwide were determined by ICP-MS after microwave-assisted digestion. Total As and Cd concentrations in the tobacco leaves ranged from 0.20 to 0.63 and 1.8 to 9.9 mg kg(-1), respectively. By the speciation analysis of As in tobacco leaves and ash by HPLC-ICP-MS following acid extraction, arsenite [As(III)] and arsenate [As(V)] were determined and trace amounts of monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA), trimethylarsine oxide (TMAO), tetramethylarsonium (TeMA) and some unidentified As species were also found. Arsenic speciation for smoke absorbed in an aqueous solution was carried out. The sum of the As species in tobacco leaves, ash and smoke was in good agreement with the result of total As determination in each sample, and the recoveries of speciation were 100 ± 10%. The distributions and the behaviors of As species were clarified.

Assessment of potential soybean cadmium excluder cultivars at different concentrations of Cd in soils.

PubMed

Zhi, Yang; He, Kangxin; Sun, Ting; Zhu, Yongqiang; Zhou, Qixing

2015-09-01

The selection of cadmium-excluding cultivars has been used to minimize the transfer of cadmium into the human food chain. In this experiment, five Chinese soybean plants were grown in three soils with different concentrations of Cd (0.15, 0.75 and 1.12mg/kg). Variations in uptake, enrichment, and translocation of Cd among these soybean cultivars were studied. The results indicated that the concentration of Cd in seeds that grew at 1.12mg/kg Cd in soils exceeded the permitted maximum levels in soybeans. Therefore, our results indicated that even some soybean cultivars grown on soils with permitted levels of Cd might accumulate higher concentrations of Cd in seeds that are hazardous to human health. The seeds of these five cultivars were further assessed for interactions between Cd and other mineral nutrient elements such as Ca, Cu, Fe, Mg, Mn and Zn. High Cd concentration in soil was found to inhibit the uptake of Mn. Furthermore, Fe and Zn accumulations were found to be enhanced in the seeds of all of the five soybean cultivars in response to high Cd concentration. Cultivar Tiefeng 31 was found to fit the criteria for a Cd-excluding cultivar under different concentrations of Cd in soils. Copyright © 2015. Published by Elsevier B.V.

Health impact assessment of arsenic and cadmium intake via rice consumption in Bangkok, Thailand.

PubMed

Hensawang, Supanad; Chanpiwat, Penradee

2017-10-31

Consumption of contaminated food is a major route of exposure to toxic contaminants for humans. To protect against potential negative health effects from rice consumption, As and Cd concentrations in rice sold in Bangkok were determined, and non-carcinogenic and carcinogenic risk assessments were conducted. Four types of rice (n = 97), namely, white jasmine, white, glutinous, and brown jasmine, were collected. Samples were acid-digested and analyzed for total concentrations of As and Cd by ICP-MS. The average concentrations of As and Cd were 0.205 ± 0.008 and 0.019 ± 0.001 mg kg -1 , respectively. Approximately 22.8, 62.5, and 57.1% of white, white jasmine, and brown jasmine rice, respectively, contained As concentrations exceeding the Codex inorganic As standards for polished and unpolished rice. Brown jasmine rice contained significantly higher As concentrations than the other types of rice. However, Cd concentrations in all rice samples were significantly lower than the Codex standard of 0.4 mg kg -1 . Children are exposed to the highest amounts of both elements. Concerning As exposure through the consumption of different types of rice in the same age group, the consumption of brown jasmine rice caused approximately 1.7 to 2.3 times higher As exposure rates compared to the consumption of other types of rice. Non-carcinogenic risks (hazard quotient (HQ)) of As exposure from all types of rice were higher than the threshold limit of 1. HQ in children ranging from 2.1 to 4.9 was significantly higher than HQ in the other age groups. The cancer risks from As exposure were negligible in all groups.

Baseflow and stormflow metal fluxes from two small agricultural catchments in the Coastal Plain of the Chesapeake Bay Basin, United States

USGS Publications Warehouse

Miller, C.V.; Foster, G.D.; Majedi, B.F.

2003-01-01

Annual yields (fluxes per unit area) of Al, Mn, Fe, Ni, Cd, Pb, Zn, Cu, Cr, Co, As and Se were estimated for two small non-tidal stream catchments on the Eastern Shore of the Chesapeake Bay, United States - a poorly drained dissected-upland watershed in the Nanticoke River Basin, and a well-drained feeder tributary in the lower reaches of the Chester River Basin. Both watersheds are dominated by agriculture. A hydrograph-separation technique was used to determine the baseflow and stormflow components of metal yields, thus providing important insights into the effects of hydrology and climate on the transport of metals. Concentrations of suspended-sediment were used as a less-costly proxy of metal concentrations which are generally associated with particles. Results were compared to other studies in Chesapeake Bay and to general trends in metal concentrations across the United States. The study documented a larger than background yield of Zn and Co from the upper Nanticoke River Basin and possibly enriched concentrations of As, Cd and Se from both the upper Nanticoke River and the Chesterville Branch (a tributary of the lower Chester River). The annual yield of total Zn from the Nanticoke River Basin in 1998 was 18,000 g/km2/a, and was two to three times higher than yields reported from comparable river basins in the region. Concentrations of Cd also were high in both basins when compared to crustal concentrations and to other national data, but were within reasonable agreement with other Chesapeake Bay studies. Thus, Cd may be enriched locally either in natural materials or from agriculture.

Watershed-scale assessment of background concentrations and guidance values for heavy metals in soils from a semiarid and coastal zone of Brazil.

PubMed

da Silva, Yuri Jacques Agra Bezerra; do Nascimento, Clístenes Williams Araújo; Cantalice, José Ramon Barros; da Silva, Ygor Jacques Agra Bezerra; Cruz, Cinthia Maria Cordeiro Atanázio

2015-09-01

Determining heavy metal background concentrations in soils is fundamental in order to support the monitoring of potentially contaminated areas. This is particularly important to areas submitted to high environmental impact where an intensive and local monitoring is required. To this end, the aim of this study was to establish background concentrations and quality reference values (QRVs) for the heavy metals Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, As, and Hg in an environmentally impacted watershed from Brazil. Geochemical associations among Fe, Mn, and trace elements were also assessed to provide an alternative tool for establishing background concentrations. A total of one hundred and four samples comprised twenty-six composite soil samples from areas of native forest or minimal anthropic influence. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES, except for As and Hg measured by atomic absorption spectrophotometer. Background concentrations of heavy metals in soils had the following decreasing order: Fe > Mn > Zn > Cr > Pb > Ni > Cu > As > Cd > Hg. These values were usually lower than those observed in the international and national literature. The QRVs for Ipojuca watershed followed the order (mg kg(-1)) Fe (13,020.40) > Mn (91.80) > Zn (30.12) > Cr (15.00) > Pb (13.12) > Cu (3.53) > Ni (3.30) > As (0.51) > Cd (0.08) > Hg (0.04). Significant correlation among Fe, Mn, and heavy metals shows that solubilization by the method 3051A provides a reasonable estimate for predicting background concentrations for Cd, Cr, and Cu as well as Zn, Cr, Cu, and Ni.

Cadmium accumulation characteristics of the winter farmland weeds Cardamine hirsuta Linn. and Gnaphalium affine D. Don.

PubMed

Lin, Lijin; Shi, Jun; Liu, Qihua; Liao, Ming'an; Mei, Luoyin

2014-07-01

In a preliminary study, we found that the cadmium (Cd) concentrations in shoots of the winter farmland weeds Cardamine hirsuta Linn. and Gnaphalium affine D. Don exceeded the critical value of a Cd-hyperaccumulator (100 mg kg(-1)), indicating that these two farmland weeds might be Cd-hyperaccumulators. In this study, we grew these species in soil containing various concentrations of Cd to further evaluate their Cd accumulation characteristics. The biomasses of C. hirsuta and G. affine decreased with increasing Cd concentrations in the soil, while the root/shoot ratio and the Cd concentrations in shoot tissues increased. The Cd concentrations in shoots of C. hirsuta and G. affine reached 121.96 and 143.91 mg kg(-1), respectively, at the soil Cd concentration of 50 mg kg(-1). Both of these concentrations exceeded the critical value of a Cd-hyperaccumulator (100 mg kg(-1)). The shoot bioconcentration factors of C. hirsuta and G. affine were greater than 1. The translocation factor of C. hirsuta was less than 1 and that of G. affine was greater than 1. These findings indicated that C. hirsuta is a Cd-accumulator and G. affine is Cd-hyperaccumulator. Both plants are distributed widely in the field, and they could be used to remediate Cd-contaminated farmland soil in winter.

Sequencing Batch Reactor (SBR) for the removal of Hg2+ and Cd2+ from synthetic petrochemical factory wastewater.

PubMed

Malakahmad, Amirhossein; Hasani, Amirhesam; Eisakhani, Mahdieh; Isa, Mohamed Hasnain

2011-07-15

Petrochemical factories which manufacture vinyl chloride monomer and poly vinyl chloride (PVC) are among the largest industries which produce wastewater contains mercury and cadmium. The objective of this research is to evaluate the performance of a lab-scale Sequencing Batch Reactor (SBR) to treat a synthetic petrochemical wastewater containing mercury and cadmium. After acclimatization of the system which lasted 60 days, the SBR was introduced to mercury and cadmium in low concentrations which then was increased gradually to 9.03±0.02 mg/L Hg and 15.52±0.02 mg/L Cd until day 110. The SBR performance was assessed by measuring Chemical Oxygen Demand, Total and Volatile Suspended Solids as well as Sludge Volume Index. At maximum concentrations of the heavy metals, the SBR was able to remove 76-90% of Hg(2+) and 96-98% of Cd(2+). The COD removal efficiency and MLVSS (microorganism population) in the SBR was affected by mercury and cadmium concentrations in influent. Different species of microorganisms such as Rhodospirilium-like bacteria, Gomphonema-like algae, and sulfate reducing-like bacteria were identified in the system. While COD removal efficiency and MLVSS concentration declined during addition of heavy metals, the appreciable performance of SBR in removal of Hg(2+) and Cd(2+) implies that the removal in SBR was not only a biological process, but also by the biosorption process of the sludge. Copyright © 2011 Elsevier B.V. All rights reserved.

[Biological risk and health care workers: analysis of the effects of work chronobiology on the immune system].

PubMed

Copertaro, A; Bracci, M; Amati, Monica; Mocchegiani, E; Barbaresi, Mariella; Copertaro, Benedetta; Santarelli, Lory

2010-01-01

Healthcare workers may be exposed to a variety of biological hazards. Although many studies have shown that some immunological alterations were related to work stress and sleep disorders, few studies investigated effects of shiftwork on the immunological system. The aim of the study was to compare the immune status of a group of nurses on shiftwork with that of nurses working only day shifts. A total of 138 nurses were evaluated at baseline and after a year of follow-up, via tests for perceived stress, daytime sleepiness, number of lymphocytes and subpopulation of CD3+, CD4+, CD8+-CD57+, CD19+ and CD56+, cytotoxic activity and lympho-prolferative response of NK cells, serum concentrations of IL-1beta, IL-6, INFgamma and TNFalpha. No significant alterations of any of the studied parameters were found both at baseline and after a year of follow-up. The biological hazards for nurses do not seem to be increased by shiftwork.

The Environment Quality, Speciation and their Origins of Heavy Metals in Surficial Sediments in Central Bohai Sea, China

NASA Astrophysics Data System (ADS)

Liu, M.; Fan, D.; Han, Z.; Liao, Y.; Chen, B.; Yang, Z.

2016-02-01

The concentrations and speciations of heavy metals (Cu, Co, Ni, Zn, Pb, Cr and Cd) in surface and core sediments collected from the central Bohai Sea were analyzed by ICP-MS, to evaluate their distribution / fractionation, pollution status and sources. The results showed that Cd exhibited gradual increasing vertically, while others were stable or declined slightly in core sediments. Metals showed higher values in `central mud area of the Bohai Sea' and the coastal area of the Bohai Bay in surface sediments. Residual fractions were the dominant forms of Cu, Co, Ni, Zn and Cr in the surface sediments, while Cd and Pb had large proportions of the total concentration in the non-residual fractions. Both the contamination factors and the geo-accumulation index indicated that Cu, Co, Ni, Cr were not polluted, while Pb, Zn, Cd were in moderate contamination. The ecological risk assessment (by sepeciations) indicated that the sediments were unpolluted with respect to the heavy metals Co, Ni and Cr and unpolluted to moderately polluted with respect to Cu, Zn, Cd and Pb. Compared with sediment quality guidelines (SQGs), Cu, Zn, Cr, Pb, Cd were likely to produce occasional adverse biological effects, while Ni showed possible ecotoxicological risks. The combined levels of the metals have a 21% probability of being toxic. Elements Cr, Co and Ni were mainly natural origined and significantly affected by the composition of sediments. Cu, Zn, Pb and especially Cd may be influenced by human activities.

Grape Juice Concentrate Protects Rat Liver Against Cadmium Intoxication: Histopathology, Cytochrome C and Metalloproteinases Expression.

PubMed

de Moura, C F G; Ribeiro, F A P; Handan, B A; Aguiar, O; Oshima, C T F; Ribeiro, D A

2016-07-01

The aim of this study was to investigate if grape juice concentrate is able to protect rat liver against cadmium toxicity. For this purpose, histopathological analysis, cytochrome C expression and immunoexpresssion of metalloproteinases (MMP) 2 and 9 were investigated. A total of 15 Wistar rats weighing 250 g on the average, and 8 weeks age were distributed into 3 groups (n=5), as follows: Control group (non-treated group, CTRL); Cadmium group (Cd) and grape juice concentrate group (Cd+GJ). Histopathological analysis revealed that liver from animals treated with grape juice concentrate improved tissue degeneration induced by cadmium intoxication. Animals intoxicated with cadmium and treated with grape juice concentrate showed higher cytochrome C gene expression in liver cells. No significant statistically differences (p>0.05) were found to MMP 2 and 9 immunoexpression between groups. Taken together, our results demonstrate that grape juice concentrate is able to prevent tissue degeneration in rat liver as a result of increasing apoptosis. © Georg Thieme Verlag KG Stuttgart · New York.

Leaching behavior of heavy metals and transformation of their speciation in polluted soil receiving simulated acid rain.

PubMed

Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

2012-01-01

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects.

Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain

PubMed Central

Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

2012-01-01

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. PMID:23185399

Cadmium-induced cyto- and genotoxicity are organ-dependent in lettuce.

PubMed

Monteiro, Cristina; Santos, Conceição; Pinho, Sónia; Oliveira, Helena; Pedrosa, Tiago; Dias, Maria Celeste

2012-07-16

Cadmium is a priority pollutant. Its mechanisms and effects within different plant organs remain unclear. Here, cyto-genotoxicity biomarkers were evaluated in roots and leaves after Cd exposure (0, 1, 10, and 50 μM) of the model crop Lactuca sativa L. (cv. "Reine de Mai"). Overall, superoxide dismutase (SOD) and catalase (CAT) activities were stimulated in leaves, where Cd accumulation was lower in comparison to that in roots. In roots, SOD and peroxidase (POX, APX) activities were stimulated. Moreover, in both organs glutathione reductase (GR) was not affected by Cd. Overall, the H(2)O(2) content increased in both organs, while the total antioxidant capacity decreased in leaves and increased in roots with Cd concentrations. In both organs, lipid and protein oxidation rose with consequent increase of membrane permeability. Simultaneously, the comet assay showed that tail moment, tail length, and % tail DNA were maximum for 1 μM. For 10 μM, shorter tails were found suggesting induced Cd-DNA adducts that lead to DNA-DNA/DNA-protein cross-links, and/or formation of longer DNA fragments, and/or impairment of DNA repair mechanisms, while at 50 μM, nucleoids sensitivity to the technique was evident. This result was consistent with the maximum micronuclei frequency found for the 10 μM Cd dose in roots, suggesting that the surviving cells in this organ had an increase of mitotic catastrophe and that DNA repair systems for blocking cell cycle were dysfunctional. In lower Cd concentrations, root cells might have developed strategies to repair damaged DNA by blocking the cell cycle at specific checkpoints, thus avoiding mitotic catastrophe. Roots at 1 μM showed a cell cycle blockage trend at the G(2) checkpoint, while those at higher concentrations presented S phase delay. We finally discuss a general model of Cd-organ interaction covering these cyto- and genotoxic effects and the potential use of this cultivar in phytoremediation strategies.

Speciation and environmental risk assessment of heavy metal in bio-oil from liquefaction/pyrolysis of sewage sludge.

PubMed

Yuan, Xingzhong; Leng, Lijian; Huang, Huajun; Chen, Xiaohong; Wang, Hou; Xiao, Zhihua; Zhai, Yunbo; Chen, Hongmei; Zeng, Guangming

2015-02-01

Liquefaction bio-oil (LBO) produced with ethanol (or acetone) as the solvent and pyrolysis bio-oil (PBO) produced at 550°C (or 850°C) from sewage sludge (SS) were produced, and were characterized and evaluated in terms of their heavy metal (HM) composition. The total concentration, speciation and leaching characteristic of HMs (Cu, Cr, Pb, Zn, Cd, and Ni) in both LBO and PBO were investigated. The total concentration and exchangeable fraction of Zn and Ni in bio-oils were at surprisingly high levels. Quantitative risk assessment of HM in bio-oils was performed by the method of risk assessment code (RAC), potential ecological risk index (PERI) and geo-accumulation index (GAI). Ni in bio-oil produced by pyrolysis at 850°C (PBO850) and Zn in bio-oil by liquefaction at 360°C with ethanol as solvent (LBO-360E) were evaluated to possess very high risk to the environment according to RAC. Additionally, Cd in PBO850 and LBO-360E were evaluated by PERI to have very high risk and high risk, respectively, while Cd in all bio-oils was assessed moderately contaminated according to GAI. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial.

PubMed

Serrano-Villar, Sergio; Sainz, Talia; Ma, Zhong-Min; Utay, Netanya S; Chun, Tae-Wook; Wook-Chun, Tae; Mann, Surinder; Kashuba, Angela D; Siewe, Basile; Albanese, Anthony; Troia-Cancio, Paolo; Sinclair, Elizabeth; Somasunderam, Anoma; Yotter, Tammy; Deeks, Steven G; Landay, Alan; Pollard, Richard B; Miller, Christopher J; Moreno, Santiago; Asmuth, David M

2016-01-01

Whether initiation of antiretroviral therapy (ART) regimens aimed at achieving greater concentrations within gut associated lymphoid tissue (GALT) impacts the level of mucosal immune reconstitution, inflammatory markers and the viral reservoir remains unknown. We included 12 HIV- controls and 32 ART-naïve HIV patients who were randomized to efavirenz, maraviroc or maraviroc+raltegravir, each with fixed-dose tenofovir disoproxil fumarate/emtricitabine. Rectal and duodenal biopsies were obtained at baseline and at 9 months of ART. We performed a comprehensive assay of T-cell subsets by flow cytometry, T-cell density in intestinal biopsies, plasma and tissue concentrations of antiretroviral drugs by high-performance liquid chromatography/mass spectroscopy, and plasma interleukin-6 (IL-6), lipoteichoic acid (LTA), soluble CD14 (sCD14) and zonulin-1 each measured by ELISA. Total cell-associated HIV DNA was measured in PBMC and rectal and duodenal mononuclear cells. Twenty-six HIV-infected patients completed the follow-up. In the duodenum, the quadruple regimen resulted in greater CD8+ T-cell density decline, greater normalization of mucosal CCR5+CD4+ T-cells and increase of the naïve/memory CD8+ T-cell ratio, and a greater decline of sCD14 levels and duodenal HIV DNA levels (P = 0.004 and P = 0.067, respectively), with no changes in HIV RNA in plasma or tissue. Maraviroc showed the highest drug distribution to the gut tissue, and duodenal concentrations correlated well with other T-cell markers in duodenum, i.e., the CD4/CD8 ratio, %CD4+ and %CD8+ HLA-DR+CD38+ T-cells. Maraviroc use elicited greater activation of the mucosal naïve CD8+ T-cell subset, ameliorated the distribution of the CD8+ T-cell maturational subsets and induced higher improvement of zonulin-1 levels. These data suggest that combined CCR5 and integrase inhibitor based combination therapy in ART treatment naïve patients might more effectively reconstitute duodenal immunity, decrease inflammatory markers and impact on HIV persistence by cell-dependent mechanisms, and show unique effects of MVC in duodenal immunity driven by higher drug tissue penetration and possibly by class-dependent effects.

Concentrations of arsenic, cadmium and lead in human hair and typical foods in eleven Chinese cities.

PubMed

Zhou, Tong; Li, Zhu; Zhang, Fan; Jiang, Xiaosan; Shi, Weiming; Wu, Longhua; Christie, Peter

2016-12-01

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) were determined in 384 human hair samples and 445 purchased food samples from 11 cities in China. The mean concentrations of hair As, Cd and Pb were 0.23, 0.062 and 2.45mgkg -1 , respectively. The As, Cd and Pb concentrations in different foods were lower than the national maximum allowable contaminant levels. By comparison, males had higher hair As concentrations but lower Cd concentrations than females. When the interaction effects of gender and age were considered, males had the higher hair As, Cd and Pb concentrations in the 51-65 year-old age group. Residents of rural areas had higher hair As, Cd and Pb concentrations than people living in urban areas. Further analysis indicates that hair As, Cd and Pb concentrations and their changes with biological and environmental factors cannot be satisfactorily explained by the estimated intakes from purchased food. Copyright © 2016 Elsevier B.V. All rights reserved.

[Association of CD(+)4 T lymphocyte count and gingival crevicular fluid prostaglandin E2 with periodontal parameters in HIV-positive periodontitis patients].

PubMed

Jia, Hongcheng; Wang, Xuan; Hua, Wenhao; Li, Xiaoguang; Hou, Wen; Fu, Qian

2014-02-01

To investigate the correlation of CD(+)4 T lymphocyte count and prostaglandin E2 (PGE2) in gingival crevicular fluid (GCF) with periodontal status in HIV-positive patients with periodontitis. Twenty subjects were selected according to inclusion criteria. The plasmatic CD(+)4 T lymphocytes were counted. All the individuals were divided into three groups, group A (CD(+)4 T lymphocyte count < 200 cell/mm(3)), group B (200 cell/mm(3) ≤ CD(+)4 T lymphocyte count ≤ 500 cell/mm(3)) and group C (CD(+)4 T lymphocyte count > 500 cell/mm(3)). Periodontal indexes, including plaque index(PLI), bleeding index(BI), attachment level(AL) and probing depth(PD) were recorded.GCF samples were taken from 120 index teeth by means of sterile paper strips.GCF PGE2 levels were determined by radioimmunoassays. Mann-Whitney was used to compare the periodontal indexes and PGE2 levels among the three groups. Partial correlations and Spearman correlations were applied to analyze the correlation of CD(+)4 T lymphocytes count and PGE2 in gingival crevicular fluid with periodontal status. BI value, PGE2 concentration and total PGE2 were 3.00(2.00), 90.75(30.60) µg/L, 447.58 (243.08) pg in group B, which were higher than those in group A[2.00(1.25), 79.75(30.50) µg/L and 339.52 (200.97) pg respectively] and group C[2.00(1.00), 73.38 (14.83) µg/L and 299.18 (108.33) pg respectively] (P < 0.0167). But the differences of PD and AL among the three groups were not significantly different(P > 0.0167). The correlations were observed between CD(+)4 T lymphocyte count and BI for the subpopulations with CD(+)4 T lymphocyte count <200 cells/mm(3) (r = 0.657, P < 0.05) and between 200-500 cells/mm(3) (r = -0.369, P < 0.05). PGE2 concentration was negatively correlated with BI, PD and AL (P < 0.05), and total PGE2 was positively correlated with PD and AL(P < 0.05). There was an association between the periodontal status and CD(+)4 T lymphocyte count in HIV(+) patients.GCF PGE2 level was related to periodontal parameters including BI, PD and AL.

Soluble immune receptor serum levels are associated with age, but not with clinical phenotype or disease severity in childhood atopic dermatitis.

PubMed

Ott, H; Wilke, J; Baron, J M; Höger, P H; Fölster-Holst, R

2010-04-01

Soluble immune receptors (SIRs) have been proposed as biomarkers in patients with atopic dermatitis (AD). However, their clinical applicability in affected children has rarely been studied. To assess the diagnostic usefulness of serum SIRs in childhood AD by correlating the obtained receptor profiles with serological parameters and clinical features such as age, AD phenotype and disease severity. We investigated 100 children with AD. The sCD14, sCD23, sCD25, sCD30, total IgE (tIgE) and eosinophilic cationic protein (ECP) were determined using sera of all children. The clinical phenotype was classified as extrinsic AD (ADe) or intrinsic AD (ADi) by the presence of allergen-specific IgE antibodies. A total of 55 male and 45 female children were recruited. The sCD23, sCD25 and sCD30 serum levels revealed significant age-dependency. At a mean SCORAD of 40 (range 8-98), none of the evaluated SIRs was correlated to disease severity. In all, 73% of patients suffered from ADe while 27% showed the ADi phenotype. None of the analysed SIRs differed significantly between ADe and ADi patients, while tIgE and ECP levels were elevated in the ADe subgroup. The current study provides evidence that sCD23, sCD25 and sCD30 serum levels are highly age-dependent. Serum concentrations of all investigated SIRs did not significantly correlate with disease severity in children with AD and were not differentially expressed in patients of different AD phenotypes. Therefore, we believe that the studied SIRs cannot be regarded as clinically useful biomarkers for the assessment of childhood AD.

Age-dependent changes of serum soluble CD30 concentration in children.

PubMed

Chrul, Slawomir; Polakowska, Ewa

2011-08-01

  CD30 was originally described as a marker on Reed-Sternberg cells in Hodgkin lymphoma. The extracellular portion of CD30 is proteolytically cleaved from CD30+ cells, to produce a soluble form of the molecule (sCD30) detectable in serum. Measurement of sCD30 concentration in serum has been suggested to be a potential tool in monitoring of inflammatory status in variety of diseases. Several investigators reported the relevance for sCD30 as a predictive marker for allograft rejection following organ transplantation. The aim of the study was to verify whether sCD30 serum concentrations may be affected by an age in healthy children. Heparinized venous blood was taken from 78 healthy children. For the analysis of sCD30 levels, the commercially available sCD30 ELISA was used. The sCD30 was detected in all serum samples and concentrations ranged from 6.75 to 68.07ng/mL. The statistical analysis of all individuals showed that sCD30 concentration was significantly age depended (r=-0.618, p<0.0001). When sCD30 concentrations were analyzed in regard to gender, no significant differences were identified in age subgroups. © 2011 John Wiley & Sons A/S.

Alteration of the number and percentage of innate immune cells in preschool children from an e-waste recycling area.

PubMed

Zhang, Yu; Xu, Xijin; Sun, Di; Cao, Junjun; Zhang, Yuling; Huo, Xia

2017-11-01

Heavy metal lead (Pb) and cadmium (Cd) are widespread environmental contaminants and exert detrimental effects on the immune system. We evaluated the association between Pb/Cd exposures and innate immune cells in children from an electronic waste (e-waste) recycling area. A total number of 294 preschool children were recruited, including 153 children from Guiyu (e-waste exposed group), and 141 from Haojiang (reference group). Pb and Cd levels in peripheral blood were measured by graphite furnace atomic absorption spectrophotometer, NK cell percentages were detected by flow cytometer, and other innate immune cells including monocytes, eosinophils, neutrophils and basophils were immediately measured by automated hematology analyzer. Results showed children in Guiyu had significantly higher Pb and Cd levels than in reference group. Absolute counts of monocytes, eosinophils, neutrophils and basophils, as well as percentages of eosinophils and neutrophils were significantly higher in the Guiyu group. In contrast, NK cell percentages were significantly lower in Guiyu group. Pb elicited significant escalation in counts of monocytes, eosinophils and basophils, as well as percentages of monocytes, but decline in percentages of neutrophils in different quintiles with respect to the first quintile of Pb concentrations. Cd induced significant increase in counts and percentages of neutrophils in the highest quintile compared with the first quintile of Cd concentrations. We concluded alteration of the number and percentage of innate immune cells are linked to higher levels of Pb and Cd, which indicates Pb and Cd exposures might affect the innate and adaptive immune response in Guiyu children. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of cadmium-spiked sediment on cadmium accumulation and bioturbation by nymphs of the burrowing mayfly Hexagenia bilineata

USGS Publications Warehouse

Bartsch, Michelle; Cope, W. Gregory; Rada, Ronald G.

1999-01-01

We assessed accumulation of cadmium (Cd) and bioturbation by nymphs of the burrowing mayfly Hexagenia bilineata as indicators of exposure to Cd-spiked sediment in a 21-d test. Surficial sediments (top 5 cm) from Pool 7 of the Upper Mississippi River were spiked with Cd to concentrations of 3, 7, and 15 µg Cd g-1 dry weight. The experimental design was completely randomized, with three Cd-spiked sediment treatments plus an unspiked sediment control (1 µg Cd g-1 dry weight), and 10 nymphs in each of six replicates per treatment. Nymphs accumulated Cd during the 21-d exposure; mean concentrations varied from 0.22 to 6.24 µg g-1 dry weight, and tissue concentrations were correlated with Cd concentration in unfiltered test water (r = 0.93, P -1 treatment (our greatest exposure concentration) did not differ significantly from the control. Concentrations of Cd in unfiltered, overlying test water increased significantly within treatments during the test, indicating that nymphs mobilized sediment-associated Cd into the overlying water, presumably through burrowing and respiratory activities.

Change of heavy metal speciation, mobility, bioavailability, and ecological risk during potassium ferrate treatment of waste-activated sludge.

PubMed

Yu, Ming; Zhang, Jian; Tian, Yu

2018-05-01

The effects of potassium ferrate treatment on the heavy metal concentrations, speciation, mobility, bioavailability, and environmental risk in waste-activated sludge (WAS) at various dosages of potassium ferrate and different treatment times were investigated. Results showed that the total concentrations of all metals (except Cd) were decreased slightly after treatment and the order of metal concentrations in WAS and treated waste-activated sludge (TWAS) was Mg > Zn > Cu > Cr > Pb > Ni > Cd. Most heavy metals in WAS remained in TWAS after potassium ferrate treatment with metal residual rates over 67.8% in TWAS. The distribution of metal speciation in WAS was affected by potassium ferrate treatment. The bioavailability and the mobility of heavy metals (except Mg) in TWAS were mitigated, compared to those in WAS. Meanwhile, the environmental risk of heavy metals (except Pb and Cu) was alleviated after potassium ferrate treatment.

Effect of chloride in soil solution on the plant availability of biosolid-borne cadmium.

PubMed

Weggler, Karin; McLaughlin, Michael J; Graham, Robin D

2004-01-01

Increasing chloride (Cl) concentration in soil solution has been shown to increase cadmium (Cd) concentration in soil solution and Cd uptake by plants, when grown in phosphate fertilizer- or biosolid-amended soils. However, previous experiments did not distinguish between the effect of Cl on biosolid-borne Cd compared with soil-borne Cd inherited from previous fertilizer history. A factorial pot experiment was conducted with biosolid application rates of 0, 20, 40, and 80 g biosolids kg(-1) and Cl concentration in soil solution ranging from 1 to 160 mM Cl. The Cd uptake of wheat (Triticum aestivum L. cv. Halberd) was measured and major cations and anions in soil solution were determined. Cadmium speciation in soil solution was calculated using GEOCHEM-PC. The Cd concentration in plant shoots and soil solution increased with biosolid application rates up to 40 g kg(-1), but decreased slightly in the 80 g kg(-1) biosolid treatment. Across biosolid application rates, the Cd concentration in soil solution and plant shoots was positively correlated with the Cl concentration in soil solution. This suggests that biosolid-borne Cd is also mobilized by chloride ligands in soil solution. The soil solution CdCl+ activity correlated best with the Cd uptake of plants, although little of the variation in plant Cd concentrations was explained by activity of CdCl+ in higher sludge treatments. It was concluded that chlorocomplexation of Cd increased the phytoavailability of biosolid-borne Cd to a similar degree as soil (fertilizer) Cd. There was a nonlinear increase in plant uptake and solubility of Cd in biosolid-amended soils, with highest plant Cd found at the 40 g kg(-1) rate of biosolid application, and higher rates (80 g kg(-1)) producing lower plant Cd uptake and lower Cd solubility in soil. This is postulated to be a result of Cd retention by CaCO3 formed as a result of the high alkalinity induced by biosolid application.

Evaluation of the irritancy and hypersensitivity potential following topical application of didecyldimethylammonium chloride

PubMed Central

Anderson, Stacey E.; Shane, Hillary; Long, Carrie; Lukomska, Ewa; Meade, B. Jean; Marshall, Nikki B.

2016-01-01

Didecyldimethylammonium chloride (DDAC) is a dialkyl-quaternary ammonium compound that is used in numerous products for its bactericidal, virucidal and fungicidal properties. There have been clinical reports of immediate and delayed hypersensitivity reactions in exposed individuals; however, the sensitization potential of DDAC has not been thoroughly investigated. The purpose of these studies was to evaluate the irritancy and sensitization potential of DDAC following dermal exposure in a murine model. DDAC induced significant irritancy (0.5 and 1%), evaluated by ear swelling in female Balb/c mice. Initial evaluation of the sensitization potential was conducted using the local lymph node assay (LLNA) at concentrations ranging from 0.0625–1%. A concentration-dependent increase in lymphocyte proliferation was observed with a calculated EC3 value of 0.17%. Dermal exposure to DDAC did not induce increased production of IgE as evaluated by phenotypic analysis of draining lymph node B-cells (IgE+B220+) and measurement of total serum IgE levels. Additional phenotypic analyses revealed significant and dose-responsive increases in the absolute number of B-cells, CD4+ T-cells, CD8+ T-cells and dendritic cells in the draining lymph nodes, along with significant increases in the percentage of B-cells (0.25% and 1% DDAC) at Day 10 following 4 days of dermal exposure. There was also a significant and dose-responsive increase in the number of activated CD44 + CD4 + and CD8+ T-cells and CD86+ B-cells and dendritic cells following exposure to all concentrations of DDAC. These results demonstrate the potential for development of irritation and hypersensitivity responses to DDAC following dermal exposure and raise concerns about the use of this chemical and other quaternary ammonium compounds that may elicit similar effects. PMID:27216637

V79 Chinese-hamster cells rendered resistant to high cadmium concentration also become resistant to oxidative stress.

PubMed Central

Mello-Filho, A C; Chubatsu, L S; Meneghini, R

1988-01-01

Chinese hamster cells (V79) resistant to high concentrations of Cd2+ in the medium were obtained by using the procedure of Beach & Palmiter [(1981) Proc. Natl. Acad. Sci. U.S.A. 78, 2110-2114], which in mouse led to amplification of metallothionein (MT) genes and to an enrichment in cellular MT. The Cd-resistant V79 clones isolated were significantly more resistant than parental cells to oxidative stress by extracellular H2O2 or a mixture of H2O2 and superoxide anion (O2-) generated by xanthine oxidase plus acetaldehyde. On a per-cell basis, there was no difference between the two cells in their total H2O2-decomposing or O2-(-)dismutating activity. The most likely explanation is that an enrichment in MT content in the Cd-resistant cells was responsible for this effect, because of the antioxidant properties already described for this protein. Images Fig. 2. PMID:2851992

A novel fractionation approach for water constituents - distribution of storm event metals.

PubMed

McKenzie, Erica R; Young, Thomas M

2013-05-01

A novel fractionation method, based on both particle size and settling characteristics, was employed to examine metal distributions among five fractions. In-stream and stormwater runoff samples were collected from four land use types: highway, urban, agricultural (storm event and irrigation), and natural. Highway samples contained the highest dissolved concentrations for most metals, and freshwater ambient water quality criteria were exceeded for Cd, Cu, Pb, and Zn in the first storm of the water year. Anthropogenic sources were indicated for Cu, Zn, Cd, and Pb in highway and urban samples, and total metal loadings (mg km(-2)) were observed to be as follows: highway > urban > agricultural storm event ∼ natural > agricultural irrigation. Notably, ∼10-fold higher suspended solids concentration was observed in the agricultural storm event sample, and suspended solids-associated metals were correspondingly elevated. Distribution coefficients revealed the following affinities: Zn, Ni, Cd, and Pb to large dense particles; and Cu, Zn, Cr, Ni, and Pb to colloidal organic matter.

A novel fractionation approach for water constituents – distribution of storm event metals

PubMed Central

McKenzie, Erica R.; Young, Thomas M.

2014-01-01

A novel fractionation method, based on both particle size and settling characteristics, was employed to examine metal distributions among five fractions. In-stream and stormwater runoff samples were collected from four land use types: highway, urban, agricultural (storm event and irrigation), and natural. Highway samples contained the highest dissolved concentrations for most metals, and freshwater ambient water quality criteria were exceeded for Cd, Cu, Pb, and Zn in the first storm of the water year. Anthropogenic sources were indicated for Cu, Zn, Cd, and Pb in highway and urban samples, and total metal loadings (mg/km2) were observed to be as follows: highway > urban > agricultural storm event ~ natural > agricultural irrigation. Notably, ~10-fold higher suspended solids concentration was observed in the agricultural storm event sample, and suspended solids-associated metals were correspondingly elevated. Distribution coefficients revealed the following affinities: Zn, Ni, Cd, and Pb to large dense particles; and Cu, Zn, Cr, Ni, and Pb to colloidal organic matter. PMID:23535891

The respective effects of soil heavy metal fractions by sequential extraction procedure and soil properties on the accumulation of heavy metals in rice grains and brassicas.

PubMed

Xiao, Ling; Guan, Dongsheng; Peart, M R; Chen, Yujuan; Li, Qiqi

2017-01-01

This study was carried out to examine heavy metal accumulation in rice grains and brassicas and to identify the different controls, such as soil properties and soil heavy metal fractions obtained by the Community Bureau of Reference (BCR) sequential extraction, in their accumulation. In Guangdong Province, South China, rice grain and brassica samples, along with their rhizospheric soil, were collected from fields on the basis of distance downstream from electroplating factories, whose wastewater was used for irrigation. The results showed that long-term irrigation using the electroplating effluent has not only enriched the rhizospheric soil with Cd, Cr, Cu, and Zn but has also increased their mobility and bioavailability. The average concentrations of Cd and Cr in rice grains and brassicas from closest to the electroplating factories were significantly higher than those from the control areas. Results from hybrid redundancy analysis (hRDA) and redundancy analysis (RDA) showed that the BCR fractions of soil heavy metals could explain 29.0 and 46.5 % of total eigenvalue for heavy metal concentrations in rice grains and brassicas, respectively, while soil properties could only explain 11.1 and 33.4 %, respectively. This indicated that heavy metal fractions exerted more control upon their concentrations in rice grains and brassicas than soil properties. In terms of metal interaction, an increase of residual Zn in paddy soil or a decrease of acid soluble Cd in the brassica soil could enhance the accumulation of Cd, Cu, Cr, and Pb in both rice grains and brassicas, respectively, while the reducible or oxidizable Cd in soil could enhance the plants' accumulation of Cr and Pb. The RDA showed an inhibition effect of sand content and CFO on the accumulation of heavy metals in rice grains and brassicas. Moreover, multiple stepwise linear regression could offer prediction for Cd, Cu, Cr, and Zn concentrations in the two crops by soil heavy metal fractions and soil properties.

Source identification of eight heavy metals in grassland soils by multivariate analysis from the Baicheng-Songyuan area, Jilin Province, Northeast China.

PubMed

Chai, Yuan; Guo, Jia; Chai, Sheli; Cai, Jing; Xue, Linfu; Zhang, Qingwei

2015-09-01

The characterization of the concentration, chemical speciation and source of heavy metals in soils is an imperative for pollution monitoring and the potential risk assessment of the metals to animal and human health. A total of 154 surface horizons and 53 underlying horizons of grassland soil were collected from the Baicheng-Songyuan area in Jilin Province, Northeast China, in which the concentrations and chemical fractionations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were investigated. The mean concentrations of heavy metals in grassland topsoil were 7.2, 0.072, 35, 16.7, 0.014, 15.2, 18.3 and 35 mg kg(-)(1) for As, Cd, Cr, Cu, Hg, Ni, Pb and Zn, respectively, and those averaged contents were lower than their China Environmental Quality Standard values for the Soils, implying that heavy metal concentrations in the studied soils were of the safety levels. The mobility sequence of the heavy metals based on the sum of the soluble, exchangeable, carbonate-bound and humic acid-bound fractions among the seven fractions decreased in the order of Cd 50.4%)>Hg (39.8%)>Cu (26.5%)>As (19.9%)>Zn (19.1%)>Ni (15.9%)>Pb (14.1%)>Cr (4.3%), suggesting Cd and Hg may pose more potential risk of soil contamination than other metals. Multivariate statistical analysis suggested that As, Cr, Cu, Ni, Pb, Zn, Cd and Hg had the similar lithogenic sources, however, Cd and Hg were more relevant to organic matter than other heavy metals, which was confirmed by the chemical speciation analysis of the metals. The study provides a base for local authority in the studied area to monitor the long term accession of heavy metals into grassland soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heavy metal displacement in chelate-irrigated soil during phytoremediation

NASA Astrophysics Data System (ADS)

Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

2003-03-01

Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

Metal enrichment of soils following the April 2012-2013 eruptive activity of the Popocatépetl volcano, Puebla, Mexico.

PubMed

Rodriguez-Espinosa, P F; Jonathan, M P; Morales-García, S S; Villegas, Lorena Elizabeth Campos; Martínez-Tavera, E; Muñoz-Sevilla, N P; Cardona, Miguel Alvarado

2015-11-01

We analyzed the total (Zn, Pb, Ni, Hg, Cr, Cd, Cu, As) and partially leachable metals (PLMs) in 25 ash and soil samples from recent (2012-2013) eruptions of the Popocatépetl Volcano in Central Mexico. More recent ash and soil samples from volcanic activity in 2012-2013 had higher metal concentrations than older samples from eruptions in 1997 suggesting that the naturally highly volatile and mobile metals leach into nearby fresh water sources. The higher proportions of As (74.72%), Zn (44.64%), Cu (42.50%), and Hg (32.86%) reflect not only their considerable mobility but also the fact that they are dissolved and accumulated quickly following an eruption. Comparison of our concentration patterns with sediment quality guidelines indicates that the Cu, Cd, Cr, Hg, Ni, and Pb concentrations are higher than permissible limits; this situation must be monitored closely as these concentrations may reach lethal levels in the future.

Effects of processing on the proximate and metal contents in three fish species from Nigerian coastal waters

PubMed Central

Bassey, Francisca I; Oguntunde, Fehintola C; Iwegbue, Chukwujindu M A; Osabor, Vincent N; Edem, Christopher A

2014-01-01

The effects of culinary practices such as boiling, frying, and grilling on the proximate compositions and concentrations of metals (Cd, Pb, Cr, Zn, Fe, Cu, Mn, Ni, and Hg) in commonly consumed fish species from the Nigerian coastal waters were investigated. The selected fish species were Polydactylus quadratifilis, Chrysicthys nigrodigitatus and Cynoglossus senegalensis. The culinary practices lead to increased protein, fat, and ash contents and decreased moisture contents of these fish species. The culinary practices resulted significant increase in the concentrations of most of the studied metals and decrease in the concentrations of Fe, Cr, and Pb in some fish types. The concentrations and estimated dietary intakes of Cd, Pb, Cr, Zn, Fe, Cu, Mn, Ni, and Hg from consumption of the processed fish were within their statutory safe limits. The individual metal target hazard quotient (THQ) values and the total THQs were less than 1 which indicates that no health risks would arise from the long-term consumption of these fish species. PMID:24936297

Effect of Cadmium and Copper Exposure on Growth, Secondary Metabolites and Antioxidant Activity in the Medicinal Plant Sambung Nyawa (Gynura procumbens (Lour.) Merr).

PubMed

Ibrahim, Mohd Hafiz; Chee Kong, Yap; Mohd Zain, Nurul Amalina

2017-10-12

A randomized complete block (RCBD) study was designed to investigate the effects of cadmium (Cd) and copper (Cu) on the growth, bioaccumulation of the two heavy metals, metabolite content and antibacterial activities in Gyanura procumbens (Lour.) Merr. Nine treatments including (1) control (no Cd and Cu); (2) Cd 2 = cadmium 2 mg/L; (3) Cd 4 = cadmium 4 mg/L; (4) Cu 70 = copper 70 mg/L; (5) Cu 140 = copper 140 mg/L); (6) Cd 2 + Cu 70 = cadmium 2 mg/L + copper 70 mg/L); (7) Cd 2 + Cu 140 = cadmium 2 mg/L + copper 70 mg/L); (8) Cd 4 + Cu 70 = cadmium 4 mg/L+ copper 70 mg/L and (9) Cd 4 + Cu 140 = cadmium 4 mg/L + copper 140 mg/L) were evaluated in this experiment. It was found that the growth parameters (plant dry weight, total leaf area and basal diameter) were reduced with the exposure to increased concentrations of Cd and Cu and further decreased under interaction between Cd and Cu. Production of total phenolics, flavonoids and saponin was observed to be reduced under combined Cd and Cu treatment. The reduction in the production of plant secondary metabolites might be due to lower phenyl alanine lyase (PAL) activity under these conditions. Due to that, the 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant potential (FRAP) and antibacterial activities was also found to be reduced by the combined treatments. The current experiments show that the medicinal properties of G. procumbens are reduced by cadmium and copper contamination. The accumulation of heavy metal also was found to be higher than the safety level recommended by the WHO in the single and combined treatments of Cd and Cu. These results indicate that exposure of G. procumbens to Cd and Cu contaminated soil may potentially harm consumers due to bioaccumulation of metals and reduced efficacy of the herbal product.

[Long-term effects of tillage methods on heavy metal accumulation and availability in purple paddy soil].

PubMed

Chang, Tong-Ju; Cui, Xiao-Qiang; Ruan, Zhen; Zhao, Xiu-Lan

2014-06-01

A long-term experiment, conducted at Southwest University since 1990, was used to evaluate the effect of tillage methods on the total and available contents of heavy metals (Fe, Mn, Cu, Zn, Pb, Cd) in the profile of purple paddy soil and the contents of those metals in root, stem leaf and brown rice. The experiment included five tillage methods: conventional tillage, paddy-upland rotation, no-tillage and fallow in winter, ridge-no-tillage and compartments-no-tillage. The results showed that the total concentrations of Fe, Cu, Zn, Pb and Cd in the soil profile had no significant differences among five treatments, but it was found that total Mn has a significant decline in 0-20 cm under conventional tillage, paddy-upland rotation and no-tillage and fallow in winter compared with ridge-no-tillage and compartments-no-tillage. The availability of Fe, Cu, Zn, Pb and Cd decreased with the increase of soil depth in all treatments, but the availability of Mn was found to be the highest in the 20-40 cm layers except those in the paddy-upland rotation. In the ploughed layer, the contents of available Fe, Mn was the highest in paddy-upland rotation, while the contents of available Zn and Pb was the highest in conventional tillage, but tillage treatments had not significant influence to the contents of available Cu. Correlation analysis showed that available Fe was significantly negatively related to the pH values and significantly negatively related to the organic matter of soils, available Mn was significantly negatively related to the pH values and organic matter of soils, whereas the available Zn was significantly positively related to total Zn. The contents of Fe, Mn in rice root, the contents of Fe, Mn, Cu and Cd in rice straw and Cu in brown rice were higher under paddy-upland rotation, ridge-no-tillage and compartments-no-tillage than those in conventional tillage and no-tillage and fellow in winter. Paddy-upland rotation can significantly lower the migration coefficient value of Cd in brown rice, and the Pb, Cd concentration in brown rice in the treatment of paddy-upland rotation was lower than the upper limit (< 0.2 mg x kg(-1)) of the National Standard for Food Hygiene for Cd concentration. The content of Fe in root was significantly and negatively related with soil pH and significantly and positively related with soil available Fe, the content of Mn in root was significantly negatively related with soil pH and significantly positively related with soil available Mn, the content of Mn in straw was significantly negatively related with soil pH, significantly positively related with soil total Mn and significantly positively related with soil available Mn, the content of Cu in straw and brown rice was significantly negatively related with soil pH, the content of Zn was significant related with soil pH and significant related with soil CEC. The content of Fe in root, Mn in root and straw and Cd in straw was positively related with soil available Fe, Mn and Cd, respectively, but was negatively related with pH in plough layer soil, Zn in straw was also negatively related with plough layer soil pH. From the results as above, it is concluded that different tillage methods can change the values of soil pH, alter the availability of heavy metal in soils, consequently affect uptake of heavy metal by rice. Of the tillage methods, paddy-upland rotation could increase the availability of Fe and Mn, but decrease the availability of Zn, Pb and Cd in purple paddy soils. Paddy-upland rotation can also increase the contents of Fe, Mn in rice root and straw, but decrease Cd content in brown rice, and could reduce the Pb, Cd contents in brown rice in a certain extent, however, attention should be given to long-term paddy-upland rotation cause of leaching of soil surface Mn.

A Diffusive Gradient-in-Thin-Film Technique for Evaluation of the Bioavailability of Cd in Soil Contaminated with Cd and Pb

PubMed Central

Wang, Peifang; Wang, Teng; Yao, Yu; Wang, Chao; Liu, Cui; Yuan, Ye

2016-01-01

Management of heavy metal contamination requires accurate information about the distribution of bioavailable fractions, and about exchange between the solid and solution phases. In this study, we employed diffusive gradients in thin-films (DGT) and traditional chemical extraction methods (soil solution, HOAc, EDTA, CaCl2, and NaOAc) to determine the Cd bioavailability in Cd-contaminated soil with the addition of Pb. Two typical terrestrial species (wheat, Bainong AK58; maize, Zhengdan 958) were selected as the accumulation plants. The results showed that the added Pb may enhance the efficiency of Cd phytoextraction which is indicated by the increasing concentration of Cd accumulating in the plant tissues. The DGT-measured Cd concentrations and all the selected traditional extractants measured Cd concentrations all increased with increasing concentration of the addition Pb which were similar to the change trends of the accumulated Cd concentrations in plant tissues. Moreover, the Pearson regression coefficients between the different indicators obtained Cd concentrations and plants uptake Cd concentrations were further indicated significant correlations (p < 0.01). However, the values of Pearson regression coefficients showed the merits of DGT, CaCl2, and Csol over the other three methods. Consequently, the in situ measurement of DGT and the ex situ traditional methods could all reflect the inhibition effects between Cd and Pb. Due to the feature of dynamic measurements of DGT, it could be a robust tool to predict Cd bioavaiability in complex contaminated soil. PMID:27271644

Cadmium distribution in forest ecosystems irrigated with treated municipal waste water and sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sidle, R.C.; Sopper, W.E.

1976-01-01

Treated municipal waste water was irrigated in an abandoned old field area from 1964 to 1974 and in a mixed hardwood area (old gamelands) from 1964 to 1974. Total applications of Cd in the old field and old gamelands areas were 0.47 and 0.61 kg/ha, respectively. White spruce (Picea glauca Moench Voss.) and wild strawberry (Fragaria virginiana Duchesne) foilage sampled from the old field showed no increase in Cd concentrations due to effluent irrigation, while goldenrod (Solidago sp. Ait.) had lower Cd levels in the treated area than in the unirrigated control area. Foilage sampled from red maple (Acer rubrummore » L.), white oak (Quercus alba L.), and wild sarsaparilla (Aralia nudicaulis L.), in the old gamelands, showed no increase in Cd as a result of waste water irrigation. Soil Cd levels were not significantly affected by waste water irrigation in either area, except for the increase in soil Cd in the 0 to 5 cm depth of the old gamelands. The Cd/Zn ratios of the vegetation foilage were not significantly different between the treated and control areas.« less

Cadmium dietary intake in the Canary Islands, Spain.

PubMed

Rubio, C; Hardisson, A; Reguera, J I; Revert, C; Lafuente, M A; González-Iglesias, T

2006-01-01

Cadmium (Cd) in the human diet constitutes a potential chronic hazard to health. In the nonsmoking general population, diet is the major source of cadmium exposure; therefore, it is important to monitor the dietary intake of this heavy metal to quantify and improve the understanding of Cd accumulation in the human body. The purpose of this study was to determine the levels of Cd in a range of food and drink commonly consumed in the Canary Islands. Food samples (420) were analyzed for Cd by atomic absorption spectrometry. The most recent nutritional survey conducted for the Canarian population was used to define the food and drink groups analyzed. The measured Cd concentrations combined with the food consumption data resulted in a total Cd intake in the Canary Islands of 0.16 microg/kg of body weight/day, which is well below the respective provisional tolerable weekly intake of Cd of 1 microg/kg of body weight per day determined by the FAO/WHO. The results are also compared with values reported for other national and international communities.

Effects of cadmium on absorption, excretion, and distribution of nickel in rats.

PubMed

Li, Zhan; Gu, Jun-Ying; Wang, Xian-Wen; Fan, Qiao-Hui; Geng, Yan-Xia; Jiao, Zong-Xian; Hou, Yi-Ping; Wu, Wang-Suo

2010-06-01

The effects of cadmium (Cd (II)) on absorption, excretion, and distribution of nickel (Ni (II)) were studied in rats using (63)Ni-NiCl(2) as radiotracer in the presence and absence of CdCl(2), through intraperitoneal injection (i.p.). The time-concentration curves in the blood were fitted with a two-compartment model. The peak time (t ((peak))) is 0.31 h in the absence of Cd (II), and it is 5.5 h in the presence of Cd (II). The levels of nickels were higher at 3 h and lower (close to zero) at 24 h in all organs of interest, except kidneys, in the absence of Cd (II). There still residue Ni (II) at 72 h post-injection in the presence of Cd (II). The Cd (II) did effect the total Ni (II) excretion 24 h post-injection. Our study showed that cadmium has a competitive effect on the absorption of nickel and an inhibitory effect on the elimination of it, so cadmium may induce the bioaccumulation of nickel in the body.

Effects of cadmium-enriched sediment on fish and amphibian embryo-larval stages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francis, P.C.; Birge, W.J.; Black, J.A.

1984-08-01

Aquatic toxicity tests were conducted to evaluate the effects of cadmium-enriched sediment on embryo-larval stages of the goldfish (Carassius auratus), leopard frog (Rana pipiens), and largemouth bass (Micropterus salmoides). Natural stream sediment was collected and enriched with cadmium to nominal concentrations of 1.0, 10.0, 100, and 1000 mg/kg. Enriched sediments were placed in Pyrex dishes and covered with 350 ml of reconstituted water. Fertilized eggs were placed in the dishes and maintained through 4 days posthatching, giving a total exposure time of 6 to 7 days. For all tests the cadmium concentrations ranged from 1.1 to 76.5 micrograms/liter in watermore » above sediments containing 1 to 1000 mg Cd/kg, respectively. Although low frequencies of mortality were observed in all tests, goldfish, leopard frog, and bass exposed to sediments enriched to 1000 mg Cd/kg accumulated 4.61, 12.55, and 60.0 micrograms Cd/g, respectively. No significant correlations were found between mortality of the goldfish and leopard frog and the cadmium concentrations in either water or sediment. However, all three species showed strong correlations between cadmium concentrations in water and tissue, sediment and tissue, and water and sediment. Tissue cadmium concentrations were related to the length of time test organisms were in direct contact with cadmium-enriched sediment.« less

Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador.

PubMed

Barraza, F; Schreck, E; Lévêque, T; Uzu, G; López, F; Ruales, J; Prunier, J; Marquet, A; Maurice, L

2017-10-01

Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg -1 , effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0-20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg -1 . Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice (Oryza sativa) System.

PubMed

Huang, Baifei; Xin, Junliang; Dai, Hongwen; Zhou, Wenjing

2017-11-01

A pot experiment was conducted to investigate the interactive effects of cadmium (Cd) and selenium (Se) on their accumulation in three rice cultivars, which remains unclear. The results showed that Se reduced Cd-induced growth inhibition, and increased and decreased Se and Cd concentrations in brown rice, respectively. Cadmium concentrations in all tissues of the hybrid were similar to those in its male parent yet significantly lower than those in its female parent. Selenium reduced Cd accumulation in rice when Cd concentration exceeded 2.0 mg kg -1 ; however Se accumulation depended on the levels of Cd exposure. Finally, Cd had minimal effect on Se translocation within the three cultivars. We concluded that Cd concentration in brown rice is a heritable trait, making crossbreeding a feasible method for cultivating high-yield, low-Cd rice cultivars. Selenium effectively decreased the toxicity and accumulation of Cd, and Cd affected Se uptake but not translocation.

CD26: A Prognostic Marker of Acute Lymphoblastic Leukemia in Children in the Post Remission Induction Phase.

PubMed

Mehde, Atheer Awad; Yusof, Faridah; Adel Mehdi, Wesen; Zainulabdeen, Jwan Abdulmohsin

2015-01-01

ALL is an irredeemable disease due to the resistance to treatment. There are several influences which are involved in such resistance to chemotherapy, including oxidative stress as a result of the generation of reactive oxygen species (ROS) and presence of hypodiploid cells. Cluster of differentiation 26 (CD26), also known as dipeptidyl peptidase-4, is a 110 kDa, multifunctional, membrane-bound glycoprotein. The aim of this study was to evaluate the clinical significance of serum CD26 in patients with acute lymphoblastic leukaemia patients in the post remission induction phase, as well as the relationship between CD26 activity and the oxidative stress status. CD26, total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI), in addition to activity of related enzymes myeloperoxidase, glutathione- s-transferase and xanthine oxidase, were analysed in sixty children with acute lymphoblastic leukaemia in the post remission induction phase. The study showed significant elevation in CD26, TOS and OSI levels in patients with acute lymphoblastic leukaemia in the post remission induction phase in comparison to healthy control samples. In contrast, myeloperoxidase, glutathione-s-transferase and xanthine oxidase activities were decreased significantly. A significant correlation between CD26 concentration and some oxidative stress parameters was evident in ALL patients. Serum levels of CD26 appear to be useful as a new biomarker of oxidative stress in children with acute lymphoblastic leukaemia in the post remission induction phase, and levels of antioxidants must be regularly estimated during the treatment of children with ALL.

Seasonal variations and relationships between environmental parameters and heavy metal concentrations in tissues of Crassostrea species and in its ambience from the tropical estuaries.

PubMed

Shenai-Tirodkar, Prachi; Gauns, Mangesh; Kumar, Girish; Ansari, Zakir

2018-05-15

This study aimed to evaluate the relationship between physicochemical parameters and heavy metal (Cu, Ni, Pb, and Cd) concentrations from sediment, seawater, and its accumulation in tissues of oyster species (Crassostrea madrasensis and C. gryphoides) from the three sites (Chicalim Bay (CB), Nerul Creek (NC), Chapora Bay (ChB)) along the Goa coast (India). Results showed enrichment of Cu and Ni in sediment exceeding the effect range low (ERL) level. The higher concentrations of Cu and Ni in sediments and in suspended particulate matter (SPM) from all the study sites are indicative of severe contamination of estuarine and associated habitats. Moreover, particulate Ni (at all the sites), Cu (at NC and ChB), Pb (at NC), and Cd (at CB and NC) concentrations were recorded more than its total loadings in surface sediment. Concentration of Cu and Cd in oyster tissue was several folds higher than its concentration in ambience. Further, this study showed that the levels of metal in oysters and their ambient environment were higher during the monsoon season. Hence, the consumption of oysters needs to be considered carefully with respect to the health hazards posed by the elevated levels of metal contaminants in certain seasons. The present study concludes that metals associated with the particulate matter in water column are the main source of metal accumulation in oyster. It is also suggested that concentration of metal pollutants in coastal and estuarine water bodies should be monitored regularly to ensure the acceptable limits of metal concentrations.

[Bioaccumulation of cadmium and zinc in tomato (Lycopersicon esculentum L.)].

PubMed

Sbartai, Hana; Djebar, Med Reda; Sbartai, Ibtissem; Berrabbah, Houria

2012-09-01

This work aims at evaluating the accumulation of cadmium (Cd) and zinc (Zn) (trace elements) in the organs of young tomato plants (Lycopersicon esculentum L. var. Rio Grande) and their effects on the rate of chlorophyll and enzyme activities involved in the antioxidant system: catalase (CAT), glutathion-S-transferase (GST) and peroxysase ascorbate (APX). Plants previously grown on a basic nutrient solution were undergoing treatment for 7 days, either by increasing concentrations of CdCl(2) or ZnSO(4) (0, 50, 100, 250, 500 μM) or by the combined concentrations of Cd and Zn (100/50, 100/100, 100/250, 100/500 μM). The results concerning the determination of metals in the various compartments of tomato plants as a function of increasing concentrations of Cd or Zn, suggest a greater accumulation of Cd and Zn in the roots compared to leaves. The combined treatment (Cd/Zn) interferes with the absorption of the two elements according to their concentrations in the culture medium. The presence of Zn at low concentrations (50 μM of Zn/100 μM Cd) has little influence on the accumulation of Cd in the roots and leaves, while the absorption of these two elements in the leaves increases and decreases in roots when their concentrations are equivalent (100/100 μM) compared to treatment alone. When the concentration of Zn is higher than that of Cd (500 μM of Zn/100 μM Cd) absorption of the latter is inhibited in the roots while increasing their translocation to the leaves. Meanwhile, the dosage of chlorophylls shows that they tend to decrease in a dose-dependent for both treatments (Cd or Cd/Zn), however, treatment with low concentrations of Zn (50 and 100 μM) stimulates chlorophyll synthesis. However, treatment with different concentrations of Cd seems to induce the activity of the enzymes studied (CAT, APX, GST). It is the same for treatment with different concentrations of Zn and this particularly for the highest concentrations. Finally, the combined treatment (Zn/Cd) also appears to cause enzyme inductions: CAT, APX and GST. Copyright © 2012 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Competition effects in cation binding to humic acid: Conditional affinity spectra for fixed total metal concentration conditions

NASA Astrophysics Data System (ADS)

David, Calin; Mongin, Sandrine; Rey-Castro, Carlos; Galceran, Josep; Companys, Encarnació; Garcés, José Luis; Salvador, José; Puy, Jaume; Cecilia, Joan; Lodeiro, Pablo; Mas, Francesc

2010-09-01

Information on the Pb and Cd binding to a purified Aldrich humic acid (HA) is obtained from the influence of different fixed total metal concentrations on the acid-base titrations of this ligand. NICA (Non-Ideal Competitive Adsorption) isotherm has been used for a global quantitative description of the binding, which has then been interpreted by plotting the Conditional Affinity Spectra of the H + binding at fixed total metal concentrations (CAScTM). This new physicochemical tool, here introduced, allows the interpretation of binding results in terms of distributions of proton binding energies. A large increase in the acidity of the phenolic sites as the total metal concentration increases, especially in presence of Pb, is revealed from the shift of the CAScTM towards lower affinities. The variance of the CAScTM distribution, which can be used as a direct measure of the heterogeneity, also shows a significant dependence on the total metal concentration. A discussion of the factors that influence the heterogeneity of the HA under the conditions of each experiment is provided, so that the smoothed pattern exhibited by the titration curves can be justified.

Cd tolerance and accumulation in the aquatic macrophyte, Chara australis: potential use for charophytes in phytoremediation.

PubMed

Clabeaux, Bernadette L; Navarro, Divina A G; Aga, Diana S; Bisson, Mary A

2011-06-15

We investigated the potential use of the alga Chara australis (R. Br.) forphytore mediation of Cd-contaminated sediments in aquatic systems. Chara tolerated up to 20 mg added Cd (kg soil)⁻¹ in laboratory culture. Chlorophyll a and b levels were not affected even at Cd concentrations that suppressed growth. Levels of glutathione were suppressed at 2-35 mg added Cd (kg soil)⁻¹ to 200-350 nmol GSH (g DW)⁻¹, while control levels were 660 nmol GSH (g DW)⁻¹). Histochemical studies showed Cd occurred throughout cell walls and cytoplasm in plants grown in 5-20 mg Cd (kg soil)⁻¹. Quantification using ICP-MS showed the maximum concentration in shoots was 72 mg Cd (kg DW)⁻¹ at 35 mg added Cd (kg soil)⁻¹, while the maximum in rhizoids was 116 mg Cd (kg DW)⁻¹ at 25 mg added Cd (kg soil)⁻¹. The bioconcentration factor (BCF, concentration in plant/concentration in soil) exceeded 1.0, the critical value for hyperaccumulators, for shoots exposed to 35 mg Cd (kg soil)⁻¹ and rhizoids exposed to ≥25 mg Cd (kg soil)⁻¹. Translocation factors (TF, shoot concentration/rhizoid concentration) did not exceed 1.0 for any treatment. While Chara cannot be considered a hyperaccumulator, it shows promise for use in phytoremediation efforts.

In situ removal of dissolved and suspended contaminants from a eutrophic pond using hybrid sand-filter.

PubMed

Vijayaraghavan, K; Joshi, Umid Man; Ping, Han; Reuben, Sheela; Burger, David F

2014-01-01

In this study, in situ hybrid sand filters were designed to remove dissolved and suspended contaminants from eutrophic pond. Currently, there are no attempts made to eradicate dissolved as well as suspended contaminants from eutrophic water system in a single step. Monitoring studies revealed that examined pond contain high chlorophyll-a content (101.8 μg L(-1)), turbidity (39.5 NTU) and total dissolved solids concentration (0.04 g L(-1)). Samples were further exposed to extensive water quality analysis, which include examining physicochemical parameters (pH, conductivity, total dissolved solids, salinity, turbidity and chlorophyll-a), metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Cr, and Ni) and anions (NO3, NO2, PO4, SO4, Cl, F and Br). To tackle pollutants, filtration system was designed to comprise of several components including fine sand, coarse sand/sorbent mix and gravel from top to bottom loaded in fiberglass tanks. All the filters (activated carbon, Sargassum and zeolite) completely removed algal biomass and showed potential to decrease pH during entire operational period of 20 h at 120 L h(-1). To examine the efficiency of filters in adverse conditions, the pond water was spiked with heavy metals (Cu, Cd, Pb, Zn, Cr, and Ni). Of the different filter systems, Sargassum-loaded filter performed exceedingly well with concentrations of heavy metals never exceeded the Environmental protection agency regulations for freshwater limits during total operational period. The total uptake capacities at the end of the fifth event were 24.9, 20.5, 0.58, 5.2, 0.091 and 2.8 mg/kg for Cr, Ni, Cu, Zn, Cd and Pb, respectively.

Immunoglobulin G (IgG) Subclass Distribution and IgG1 Avidity of Antibodies in Human Immunodeficiency Virus-Infected Individuals after Revaccination with Tetanus Toxoid

PubMed Central

Kroon, F. P.; van Tol, M. J. D.; Jol-van der Zijde, C. M.; van Furth, R.; van Dissel, J. T.

1999-01-01

In human immunodeficiency virus (HIV)-infected individuals the amount of antibodies formed after vaccination with T-cell-dependent recall antigens such as tetanus toxoid is proportional to the peripheral blood CD4+ T-lymphocyte counts. To investigate whether the immunoglobulin G (IgG) subclass distribution and avidity of the antibodies produced after vaccination are affected as well, we gave 13 HIV-infected adults with low CD4+ T-lymphocyte counts (<200 × 106/liter; group I), 11 HIV-infected adults with intermediate CD4+ T-lymphocyte counts (≥200 × 106/liter; group II), and 5 healthy controls booster immunizations with tetanus toxoid. The prevaccination antibody concentrations against tetanus toxoid were similar in the HIV-infected and healthy adults. After vaccination the total IgG and the IgG1 anti-tetanus toxoid antibody concentrations were significantly lower in group I than in group II and the controls. The avidity of the IgG1 anti-tetanus toxoid antibodies formed by HIV-infected adults was within the range for healthy controls, irrespective of their CD4+ T-lymphocyte counts. PMID:10225835

Effects of cadmium-spiked sediment on cadmium accumulation and bioturbation by nymphs of the burrowing mayfly Hexagenia bilineata

USGS Publications Warehouse

Bartsch, M.R.; Cope, W.G.; Rada, R.G.

1999-01-01

We assessed accumulation of cadmium (Cd) and bioturbation by nymphs of the burrowing mayfly Hexagenia bilineata as indicators of exposure to Cd- spiked sediment in a 21-d test. Surficial sediments (top 5 cm) from Pool 7 of the Upper Mississippi River were spiked with Cd to concentrations of 3, 7, and 15 ??g Cd g-1 dry weight. The experimental design was completely randomized, with three Cd-spiked sediment treatments plus an unspiked sediment control (1 ??g Cd g-1 dry weight), and 10 nymphs in each of six replicates per treatment. Nymphs accumulated Cd during the 21-d exposure; mean concentrations varied from 0.22 to 6.24 ??g g-1 dry weight, and tissue concentrations were correlated with Cd concentration in unfiltered test water (r = 0.93, P < 0.01) and test sediment (r = 0.93, P < 0.01). The effect of Cd on bioturbation by nymphs, as indicated by turbidity, differed significantly among treatments (P = 0.045) and over time within treatments (P = 0.01). Turbidity progressively decreased as Cd concentration in the sediment increased, up to 7 ??g g-1; however, turbidity in the 15 ??g g-1 treatment (our greatest exposure concentration) did not differ significantly from the control. Concentrations of Cd in unfiltered, overlying test water increased significantly within treatments during the test, indicating that nymphs mobilized sediment-associated Cd into the overlying water, presumably through burrowing and respiratory activities.

The role of organic selenium in cadmium toxicity: effects on broiler performance and health status.

PubMed

Al-Waeli, A; Zoidis, E; Pappas, A C; Demiris, N; Zervas, G; Fegeros, K

2013-03-01

This work was part of a project designed to assess whether organic selenium (Se) can protect against the toxic effects of cadmium (Cd). A total of 300 1-day-old, as hatched, broilers were randomly distributed in four dietary treatments with five replicate pens per treatment. In T1 treatment, broilers were fed a diet with 0.3 mg/kg added Se, as Se-yeast, without added Cd; in T2, broilers were fed a diet with 0.3 mg/kg Se and 10 mg/kg Cd; in T3, broilers were fed a diet with 0.3 mg/kg Se and 100 mg/kg of Cd; and in T4 treatment broilers were fed a diet with 3 mg/kg Se and 100 mg/kg Cd. The Cd was added to diets T2, T3 and T4 as CdCl2. On the 4th and 6th week, two broilers per replicate pen were killed in order to obtain whole blood, liver, kidney and breast samples. Body mass, feed conversion ratio and mortality were assessed and haematological analyses were performed. Se and Cd levels in tissues were analysed by inductively coupled plasma mass spectrometry. Broilers supplemented with 0.3 mg/kg Se can tolerate low levels of Cd added to the diets, as there were no significant negative effects on the examined performance parameters, whereas addition of excess Cd led to an impairment of broilers' performance. Mortality of broilers did not differ between the four dietary treatments at any interval point or the whole period. The examined haematological parameters such as haematocrit, total blood protein concentration, and leukocytes types ranged within physiological values, revealing no negative health effects after simultaneous Cd and Se addition. The present study indicated that Se can help against the negative effects of Cd, but cannot counteract all of its negative effects.

Leaching characteristics of EDTA-enhanced phytoextraction of Cd and Pb by Zea mays L. in different particle-size fractions of soil aggregates exposed to artificial rain.

PubMed

Lu, Yayin; Luo, Dinggui; Lai, An; Liu, Guowei; Liu, Lirong; Long, Jianyou; Zhang, Hongguo; Chen, Yongheng

2017-01-01

Chelator-assisted phytoextraction is an alternative and effective technique for the remediation of heavy metal-contaminated soils, but the potential for heavy metal leaching needs to be assessed. In the present study, a soil column cultivation-leaching experiment was conducted to investigate the Cd and Pb leaching characteristics during assisted phytoextraction of metal-contaminated soils containing different particle-size soil aggregates. The columns were planted with Zea mays "Zhengdan 958" seedlings and treated with combined applications of EDTA and simulated rainfall (pH 4.5 or 6.5). The results were as follows: (1) The greatest uptake of Cd and Pb by Z. mays was observed after treatment with EDTA (2.5 mmol kg -1 soil) and soil aggregates of <1 mm; uptake decreased as the soil aggregate size increased. (2) Simulated rainfall, especially acid rain (pH 4.5), after EDTA applications led to the increasing metal concentrations in the leachate, and EDTA significantly increased the concentrations of both Cd and Pb in the leachate, especially with soil aggregates of <1 mm; metal leachate concentrations decreased as soil particle sizes increased. (3) Concentrations of Cd and Pb decreased with each continuing leachate collection, and data were fit to linear regression models with coefficients of determination (R 2 ) above 0.90 and 0.87 for Cd and Pb, respectively. The highest total amounts of Cd (22.12%) and Pb (19.29%) were observed in the leachate of soils treated with EDTA and artificial acid rain (pH 4.5) with soil aggregates of <1 mm. The application of EDTA during phytoextraction method increased the leaching risk in the following order: EDTA 2.5-1 (pH 4.5) > EDTA 2.5-1 (pH 6.5) > EDTA 2.5-2 (pH 4.5) > EDTA 2.5-4 (pH 4.5) > EDTA 2.5-2 (pH 6.5) > EDTA 2.5-4 (pH 6.5).

Heavy metals in fish tissues/stomach contents in four marine wild commercially valuable fish species from the western continental shelf of South China Sea.

PubMed

Gu, Yang-Guang; Lin, Qin; Huang, Hong-Hui; Wang, Liang-Gen; Ning, Jia-Jia; Du, Fei-Yan

2017-01-30

The concentrations of heavy metals (Cd, Pb, Cr, Ni, Cu and Zn) were determined in four commercially valuable fish species (Thunnus obesus, Decapterus lajang, Cubiceps squamiceps and Priacanthus macracanthus), collected in the western continental shelf of the South China Sea. Concentrations of Cd, Pb, Cr, Ni, Cu, and Zn in fish muscles were 0.006-0.050, 0.13-0.68, 0.18-0.85, 0.11-0.25, 0.12-0.77, and 2.41-4.73μg/g, wet weight, respectively. Concentrations of heavy metals in all species were below their acceptable daily upper limit, suggesting human consumption of these wild fish species may be safe, with health risk assessment based on the target hazard quotients (THQ) and total THQ, indicating no significant adverse health effects with consumption. The average concentrations of Zn were higher in gills than in stomach contents, backbones or muscle, while conversely, the other heavy metals had higher concentrations in stomach contents than in other tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of sodium dodecyl sulfate on the conformation and hemolytic activity of St I and St II, two isotoxins purified from Stichodactyla helianthus.

PubMed

Lanio, M E; Alvarez, C; Pazos, F; Martinez, D; Martínez, Y; Casallanovo, F; Abuin, E; Schreier, S; Lissi, E

2003-01-01

The effect of sodium dodecyl sulfate (SDS) upon the conformation and hemolytic activity of St I and St II strongly depends on its concentration. At relatively low surfactant concentrations (ca. 0.5-5mM range) the surfactant leads to the formation of aggregates, as suggested by the turbidity observed even at relatively low (micromolar range) protein concentrations. In this surfactant range, the proteins show an increase in intrinsic fluorescence intensity and reduced quenching by acrylamide, with an almost total loss of its hemolytic activity. At higher surfactant concentrations the protein adducts disaggregates. This produces a decrease in fluorescence intensity, increase in quenching efficiency by acrylamide, loss of the native tertiary conformation (as reported by the near UV-CD spectra), and increase in alpha-helix content (as evidenced by the far UV-CD spectra). However, and in spite of these substantial changes, the toxins partially recover their hemolytic activity. The reasons for this recovering of the activity at high surfactant concentrations is discussed.

Defective renal water handling in transgenic mice over-expressing human CD39/NTPDase1

PubMed Central

Zhang, Yue; Morris, Kaiya L.; Sparrow, Shannon K.; Dwyer, Karen M.; Enjyoji, Keiichi; Robson, Simon C.

2012-01-01

Ectonucleoside triphosphate diphosphohydrolase-1 hydrolyzes extracellular ATP and ADP to AMP. Previously, we showed that CD39 is expressed at several sites within the kidney and thus may impact the availability of type 2 purinergic receptor (P2-R) ligands. Because P2-Rs appear to regulate urinary concentrating ability, we have evaluated renal water handling in transgenic mice (TG) globally overexpressing hCD39. Under basal conditions, TG mice exhibited significantly impaired urinary concentration and decreased protein abundance of AQP2 in the kidney compared with wild-type (WT) mice. Urinary excretion of total nitrates/nitrites was significantly higher in TG mice, but the excretion of AVP or PGE2 was equivalent to control WT mice. There were no significant differences in electrolyte-free water clearance or fractional excretion of sodium. Under stable hydrated conditions (gelled diet feeding), the differences between the WT and TG mice were negated, but the decrease in urine osmolality persisted. When water deprived, TG mice failed to adequately concentrate urine and exhibited impaired AVP responses. However, the increases in urinary osmolalities in response to subacute dDAVP or chronic AVP treatment were similar in TG and WT mice. These observations suggest that TG mice have impaired urinary concentrating ability despite normal AVP levels. We also note impaired AVP release in response to water deprivation but that TG kidneys are responsive to exogenous dDAVP or AVP. We infer that heightened nucleotide scavenging by increased levels of CD39 altered the release of endogenous AVP in response to dehydration. We propose that ectonucleotidases and modulated purinergic signaling impact urinary concentration and indicate potential utility of targeted therapy for the treatment of water balance disorders. PMID:22622462

Cadmium distribution in field-grown fruit trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korcak, R.F.

The effect of soil applied Cd on Cd distribution in and growth of five species of fruit trees was investigated. Cadmium was applied at three rates (0, 5, and 10 mg kg{sup {minus}1} soil) as CdSO{sub 4} to orchard plots established at two pH levels, low (5.5) and high (6.5). Five fruit tree types were planted: Gala apple (Malus domestica Borkh.) budded on M.26 (dwarfing) or MM.111 (semistandard) rootstocks, Redskin peach (Prunus persica L.) on Lovell rootstock, Stanley plum (Prunus domestica L.) on Myrobalon rootstock, and Seckel pear (Pyrus communis L.) on seedling rootstock. The trees were grown for 6more » yr, 7 yr in the case of pear, and leaf, bark, wood, fruit, and root Cd concentrations were monitored. Gala apple on both rootstocks accumulated very small concentrations of Cd, usually 0.1 mg kg{sup {minus}1} dry wt. in all tissues tested. Peach and plum were intermediate in Cd accumulation, but both still relatively low. Seckel pear had high Cd concentrations in all tissues including fruit flesh and peel. Pear leaf Cd concentrations were 2.0 mg kg{sup {minus}1} from the 10 mg kg{sup {minus}1} soil Cd application after 5 yr. Pear fruit peel and flesh showed elevated, although nonsignificant, Cd concentrations with increased Cd applied. There was little difference between bark and wood tissue Cd concentrations independent of tree type. Root Cd concentrations were highest for pear followed by peach and plum, and lowest in apple.« less

Assessment of heavy metal pollution and human health risk in urban soils of steel industrial city (Anshan), Liaoning, Northeast China.

PubMed

Qing, Xiao; Yutong, Zong; Shenggao, Lu

2015-10-01

The purpose of this study was to determine the concentrations and health risk of heavy metals in urban soils from a steel industrial district in China. A total of 115 topsoil samples from Anshan city, Liaoning, Northeast China were collected and analyzed for Cr, Cd, Pb, Zn, Cu, and Ni. The geoaccumulation index (Igeo), pollution index (PI), and potential ecological risk index (PER) were calculated to assess the pollution level in soils. The hazard index (HI) and carcinogenic risk (RI) were used to assess human health risk of heavy metals. The average concentration of Cr, Cd, Pb, Zn, Cu, and Ni were 69.9, 0.86, 45.1, 213, 52.3, and 33.5mg/kg, respectively. The Igeo and PI values of heavy metals were in the descending order of Cd>Zn>Cu>Pb>Ni>Cr. Higher Igeo value for Cd in soil indicated that Cd pollution was moderate. Pollution index indicated that urban soils were moderate to highly polluted by Cd, Zn, Cu, and Pb. The spatial distribution maps of heavy metals revealed that steel industrial district was the contamination hotspots. Principal component analysis (PCA) and matrix cluster analysis classified heavy metals into two groups, indicating common industrial sources for Cu, Zn, Pb, and Cd. Matrix cluster analysis classified the sampling sites into four groups. Sampling sites within steel industrial district showed much higher concentrations of heavy metals compared to the rest of sampling sites, indicating significant contamination introduced by steel industry on soils. The health risk assessment indicated that non-carcinogenic values were below the threshold values. The hazard index (HI) for children and adult has a descending order of Cr>Pb>Cd>Cu>Ni>Zn. Carcinogenic risks due to Cr, Cd, and Ni in urban soils were within acceptable range for adult. Carcinogenic risk value of Cr for children is slightly higher than the threshold value, indicating that children are facing slight threat of Cr. These results provide basic information of heavy metal pollution control and environment management in steel industrial regions. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of Co-planted Purslane (Portulaca Oleracea L.) on Cd Accumulation by Sunflower in Different Levels of Cd Contamination and Salinity: A Pot Study.

PubMed

Ashrafi, Ali; Zahedi, Morteza; Soleimani, Mohsen

2015-01-01

Heavy metal bioaccumulation can be affected by various crop-weed interactions that potentially exist in agroecosystems. A pot experiment was conducted to evaluate the role of rhizosphere interaction of sunflower and purslane (Portulaca oleracea L.) weed on cadmium (Cd) uptake and its allocation to sunflower grains. The experimental treatments consisted of two cropping systems (mono and mixed culture), two adjusted salinity levels (0 and 0.5% NaCl) and three artificial levels of Cd in soil (Control, 3 and 6 mg kg(-1)). The results showed that the growth of sunflower in the presence of purslane in comparison to mono culture of sunflower led to change of total Cd content and Cd allocated to grains only in saline conditions. Promoting effects of salinity on Cd concentration of grain were alleviated where sunflower was co-planted with purslane. Besides, supply of Zn in grains of co-planted sunflower was strongly affected by salinity. Results of this study revealed that although co-planted purslane could alter conditions in the shared rhizosphere, it had no effect on enhancing Cd uptake by neighboring sunflower directly.

Lipopolysaccharide modulation of a CD14-like molecule on porcine alveolar macrophages

NASA Technical Reports Server (NTRS)

Kielian, T. L.; Ross, C. R.; McVey, D. S.; Chapes, S. K.; Blecha, F.; Spooner, B. S. (Principal Investigator)

1995-01-01

Cluster of differentiation antigen 14 (CD14) functions as a receptor for lipopolysaccharide (LPS) LPS-binding protein (LBP) complexes. Because LPS has varying effects on CD14 expression in vitro, we evaluated CD14 expression in response to LPS with a fully differentiated macrophage phenotype, the alveolar macrophage. By using flow microfluorometric analysis and a radioimmunoassay with an anti-human CD14 monoclonal antibody (My4) that cross-reacts with porcine CD14, we found that macrophages stimulated with LPS for 24 h exhibited a two- to fivefold increase in CD14-like antigen compared with unstimulated cells. At low concentrations of LPS, up-regulation of the CD14-like antigen was dependent on serum; at higher concentrations of LPS, serum was not required. In the absence of serum a 10-fold higher dose of LPS (10 ng/ml) was required to increase CD14-like expression. In addition, LPS-induced CD14-like up-regulation correlated with secretion of tumor necrosis factor-alpha, regardless of serum concentration. Blockade with My4 antibody significantly inhibited LPS-induced tumor necrosis factor-alpha secretion at 1 ng/ml of LPS. However, inhibition decreased as we increased the LPS concentration, suggesting the existence of CD14-independent pathways of macrophage activation in response to LPS. Alternatively, My4 may have a lower affinity for the porcine CD14 antigen than LPS, which may have only partially blocked the LPS-LBP binding site at high concentrations of LPS. Therefore, these data suggest that LPS activation of porcine alveolar macrophages for 24 h increased CD14-like receptor expression. The degree of CD14-like up-regulation was related to LPS concentration, however, activation did not require the presence of serum at high concentrations of LPS.

Micronutrients decrease incidence of common infections in type 2 diabetic outpatients.

PubMed

Liu, Yinghua; Jing, Hongjiang; Wang, Jin; Zhang, Rongxin; Zhang, Yuehong; Zhang, Yong; Xu, Qing; Yu, Xiaoming; Xue, Changyong

2011-01-01

A randomized, double-blind, placebo-controlled trial was carried out to investigate the effects of micronutrients supplementation on immunity and the incidence of common infections in type 2 diabetic outpatients. A total of 196 type 2 diabetic outpatients were randomized to receive tablets of micronutrients (n=97) or placebo (n=99) for 6 months. Individualized dietary energy intake and daily physical activity were recommended. Anthropometric measurements, blood biochemical variables and the incidence of common infections were measured at baseline and at 6 months. Data on diet, exercise and infection (upper respiratory tract infection, skin infection, urinary and genital tract infections, other infections) were recorded 1 month before the study and every month during the study. Blood concentrations of total protein, iron (Fe), folic acid and hemoglobin increased and unsaturated iron-binding capacity(UIBC) levels were decreased in the micronutrients supplementation group compared to the placebo group at 6 months. Moreover, at 6 months, compared to the placebo group, the blood concentrations of IgE, CD4+, CD4+/CD8+, WBC, lymphocyte counts, basophilic leukocyte increased and CD8+ count decreased in the supplementation group, and the levels of IgA, IgM, IgG and complements C3 and C4 did not differ. The incidence of upper respiratory infection, whitlow, dermapostasis, vaginitis, urinary tract infection, gingivitis and dental ulcer were lower and body temperature and duration of fever greatly improved in the supplementation than the placebo group. These data indicated that supplementation of micronutrients might increase immune function and reduce the incidence of common infections in type 2 diabetic outpatients.

Can arbuscular mycorrhizal fungi reduce Cd uptake and alleviate Cd toxicity of Lonicera japonica grown in Cd-added soils?

NASA Astrophysics Data System (ADS)

Jiang, Qiu-Yun; Zhuo, Feng; Long, Shi-Hui; Zhao, Hai-Di; Yang, Dan-Jing; Ye, Zhi-Hong; Li, Shao-Shan; Jing, Yuan-Xiao

2016-02-01

A greenhouse pot experiment was conducted to study the impact of arbuscular mycorrhizal fungi-Glomus versiforme (Gv) and Rhizophagus intraradices (Ri) on the growth, Cd uptake, antioxidant indices [glutathione reductase (GR), ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), ascorbate (ASA), glutathione (GSH) and malonaldehyde (MDA)] and phytochelatins (PCs) production of Lonicera japonica in Cd-amended soils. Gv and Ri significantly increased P acquisition, biomass of shoots and roots at all Cd treatments. Gv significantly decreased Cd concentrations in shoots and roots, and Ri also obviously reduced Cd concentrations in shoots but increased Cd concentrations in roots. Meanwhile, activities of CAT, APX and GR, and contents of ASA and PCs were remarkably higher in Gv/Ri-inoculated plants than those of uninoculated plants, but lower MDA and GSH contents in Gv/Ri-inoculated plants were found. In conclusion, Gv and Ri symbiosis alleviated Cd toxicity of L. japonica through the decline of shoot Cd concentrations and the improvement of P nutrition, PCs content and activities of GR, CAT, APX in inoculated plants, and then improved plant growth. The decrease of shoot Cd concentrations in L. japonica inoculated with Gv/Ri would provide a clue for safe production of this plant from Cd-contaminated soils.

Heavy metal concentrations in earthworms from soil amended with sewage sludge

USGS Publications Warehouse

Beyer, W.N.; Chaney, R.L.; Mulhern, B.M.

1982-01-01

Metal concentrations in soil may be elevated considerably when metal-laden sewage sludge is spread on land. Metals in earthworms (Lumbricidae) from agricultural fields amended with sewage sludge and from experimental plots were examined to determine if earthworms are important in transferring metals in soil to wildlife. Earthworms from four sites amended with sludge contained significantly (P . < 0.05) more Cd (12 times), Cu (2.4 times), Zn (2.0 times), and Pb (1.2 times) than did earthworms from control sites, but the concentrations detected varied greatly and depended on the particular sludge application. Generally, Cd and Zn were concentrated by earthworms relative to soil, and Cu, Pb, and Ni were not concentrated. Concentrations of Cd, Zn, Cu, and Pb in earthworms were correlated (P < 0.05) with those in soil. The ratio of the concentration of metals in earthworms to the concentration of metals in soil tended to be lower in contaminated soil than in clean soil. Concentrations of Cd as high as 100 ppm (dry wt) were detected in earthworms from soil containing only 2 ppm Cd. These concentrations are considered hazardous to wildlife that eat worms. Liming soil decreased Cd concentrations in earthworms slightly (P < 0.05) but had no discernible effect on concentrations of the other metals studied. High Zn concentrations in soil substantially reduced Cd concentrations in earthworms.

Bioaccumulation of selected heavy metals and histopathological and hematobiochemical alterations in backyard chickens reared in an industrial area, India.

PubMed

Kar, Indrajit; Mukhopadhayay, Sunit Kumar; Patra, Amlan Kumar; Pradhan, Saktipada

2018-02-01

This study was carried out to determine the concentrations of four heavy metals, cadmium (Cd), lead (Pb), copper (Cu), and cobalt (Co), and histopathological lesions in tissues of chickens reared in an industrial area of West Bengal, India. In particular, Mejhia Block was selected as a heavy metal-exposed area and Vatar Block (120 km away from industrially polluted areas) as a reference site. Samples were collected from the backyard chickens in these areas. Concentrations of heavy metals in soil, water, feedstuffs, tissues (liver, kidney, spleen, lung, and muscle), and droppings were greater (p < 0.05) in the polluted site than in the reference site. The greatest tissue concentrations of Cd and Pb were noted in the kidney, followed by the liver, lung, spleen, and muscle, whereas Cu and Co concentrations accumulated in these tissues resulted in the following: liver > kidney > lung > spleen > muscle. Heavy metal concentrations were greater in older chickens (> 1 year) than in young chickens (< 1 year). Packed cell volume, total erythrocyte counts, hemoglobin, total protein, and total leucocyte counts were significantly (p < 0.01) lower in the blood picture of chickens in the exposed area. Different serum enzymes and biochemical profiles were altered due to heavy metal exposure. Histological changes revealed necrotic lesions and tubulitis in the kidney, degeneration and necrosis in liver parenchyma, and periarteriolitis, peribronchiolitis, and presence of hemosiderin pigment in the lung of chickens in the exposed site. Results indicated that backyard chickens in heavy metal-exposed site may show pathological lesions in different tissues due to accumulation of heavy metals, and thus, the consumption of chicken meat from the industrially exposed site may pose a potential health risk to local residents of polluted sites.

Characterization and environmental risk assessment of heavy metals found in fly ashes from waste filter bags obtained from a Chinese steel plant.

PubMed

Zhou, Yun; Ning, Xun-an; Liao, Xikai; Lin, Meiqing; Liu, Jingyong; Wang, Jianghui

2013-09-01

The environmental risk of exposure to six heavy metals (Cu, Pb, Zn, Cr, Ni, and Cd) found in fly ashes from waste filter bags obtained from a steel plant was estimated based on the mineralogical compositions, total concentrations and speciation of the metals in the fly ashes. The results indicated that the fly ashes mainly consisted of hematite, magnetite, cyanite, spinel, coesite and amorphous materials. The concentrations of Zn and Pb were much higher than that of other materials. After Zn and Pb, Ni was present in the highest concentration, followed by Cu, Cr and Cd. Each heavy metal was distributed differently in fly ashes. The levels of Zn, Cd and Pb in the active fraction were very high, and ranged from 64.83 to 81.96%, 34.48 to 82.4% and 6.92 to 79.65% respectively, while Cu, Cr and Ni were mainly present in the residual fraction. The risk assessment code (RAC) values of fly ashes showed that the Zn and Cd present in the H3 sample presented a very high risk, with RAC values greater than 50%. The Cu present in the H3 sample, Cd in the H2 sample and Zn in the H4 and H5 samples presented a high risk. The Pb present in the H2 sample, Cd in the H4 sample, Ni in the H1 and H5 samples, and Zn in the H1 sample presented a medium risk. A low risk was presented by the Cu present in the H1, H2, H4 and H5 samples, the Pb in the H1, H3 and H5 samples, the Cd in the H1 and H5 samples, and the Ni in the H2 sample. No risk was presented by Cr in any sample. Copyright © 2013 Elsevier Inc. All rights reserved.

Distinct physiological responses of tomato and cucumber plants in silicon-mediated alleviation of cadmium stress

PubMed Central

Wu, Jiawen; Guo, Jia; Hu, Yanhong; Gong, Haijun

2015-01-01

The alleviative effects of silicon (Si) on cadmium (Cd) toxicity were investigated in cucumber (Cucumis sativus L.) and tomato (Solanum lycopersicum L.) grown hydroponically. The growth of both plant species was inhibited by 100 μM Cd, but Si application counteracted the adverse effects on growth. Si application significantly decreased the Cd concentrations in shoots of both species and roots of cucumber. The root-to-shoot transport of Cd was depressed by added Si in tomato whereas it was increased by added Si in cucumber. The total content of organic acids was decreased in tomato leaves but increased in cucumber roots and leaves by Si application under Cd stress. Si application also increased the cell wall polysaccharide levels in the roots of both species under Cd toxicity. Si-mediated changes in levels of organic acids and cell wall polysaccharides might contribute to the differences in Cd transport in the two species. In addition, Si application also mitigated Cd-induced oxidative damage in both species. The results indicate that there were different mechanisms for Si-mediated decrease in shoot Cd accumulation: in tomato, Si supply decreased root-to-shoot Cd transport; whereas in cucumber, Si supply reduced the Cd uptake by roots. It is suggested that Si-mediated Cd tolerance is associated with different physiological responses in tomato and cucumber plants. PMID:26136764

On the certification of cadmium at trace and ultratrace levels in standard reference materials using ID ICP-MS.

PubMed

Murphy, K E; Long, S E; Vocke, R D

2007-04-01

Analytical methods used for the isotope dilution inductively coupled plasma mass spectrometric (ID-ICP-MS) measurement of Cd at microg kg(-1) and sub-microg kg(-1) levels are described and applied to the certification of new dietary supplement, blood, and serum Standard Reference Materials (SRMs). The materials are: SRM 3240 Ephedra sinica Stapf Aerial Parts, SRM 3241 Ephedra sinica Stapf Native Extract, SRM 3243 Ephedra-Containing Solid Oral Dosage Form, SRM 3244 Ephedra-Containing Protein Powder, SRM 966 Toxic Metals in Bovine Blood, Level 1 (L1) and Level 2 (L2), and SRM 1598a Animal Serum. The concentration of Cd in the materials ranges from 120 microg kg(-1) down to 0.03 microg kg(-1). At these levels, the factors that most influence the accuracy of the ICP-MS data are the procedure blank and spectral and nonspectral interferences. Nonspectral interference, caused by the high concentration of dissolved solids in the matrices investigated, resulted in signal suppression. Matrix separation was used to enhance signal intensity and to reduce spectral interference for the accurate determination of Cd in SRM 1598a and SRM 3244. Chromatographic separation procedures using Chelex for SRM 1598a and anion exchange for SRM 3244 were optimized to achieve the desired separation characteristics without substantially increasing the procedure blank. Sensitivity for the determination of Cd in serum was additionally enhanced through the use of desolvation nebulization. We determined that separations were not required for the accurate ICP-MS determination of Cd in SRM 3240, SRM 3241, SRM 3243, and SRM 966 L2 under optimized analysis conditions. These samples were diluted to a minimum volume and introduced to the ICP-MS via low flow (40-100 microL/min) microconcentric nebulizers. SRM 966 L1 was also analyzed directly, but results were highly variable. The ID-ICP-MS sample preparation and ratio measurement protocols described here resulted in total expanded uncertainties of less than 1% for the determination of 90.85 microg kg(-1) Cd in SRM 3240, and less than 10% total expanded uncertainty for the determination of 0.0468 microg kg(-1) Cd in SRM 1598a.

Growth, cadmium uptake and accumulation of maize (Zea mays L.) under the effects of arbuscular mycorrhizal fungi.

PubMed

Liu, Lingzhi; Gong, Zongqiang; Zhang, Yulong; Li, Peijun

2014-12-01

The effects of three arbuscular mycorrhizal fungi isolates on Cd uptake and accumulation by maize (Zea mays L.) were investigated in a planted pot experiment. Plants were inoculated with Glomus intraradices, Glomus constrictum and Glomus mosseae at three different Cd concentrations. The results showed that root colonization increased with Cd addition during a 6-week growth period, however, the fungal density on roots decreased after 9-week growth in the treatments with G. constrictum and G. mosseae isolates. The percentage of mycorrhizal colonization by the three arbuscular mycorrhizal fungi isolates ranged from 22.7 to 72.3%. Arbuscular mycorrhizal fungi inoculations decreased maize biomass especially during the first 6-week growth before Cd addition, and this inhibitory effect was less significant with Cd addition and growth time. Cd concentrations and uptake in maize plants increased with arbuscular mycorrhizal fungi colonization at low Cd concentration (0.02 mM): nonetheless, it decreased at high Cd concentration (0.20 mM) after 6-week growth period. Inoculation with G. constrictum isolates enhanced the root Cd concentrations and uptake, but G. mosseae isolates showed the opposite results at high Cd concentration level after 9 week growth period, as compared to non-mycorrhizal plants. In conclusion, maize plants inoculated with arbuscular mycorrhizal fungi were less sensitive to Cd stress than uninoculated plants. G. constrictum isolates enhanced Cd phytostabilization and G. mosseae isolates reduced Cd uptake in maize (Z. mays L.).

Factors affecting food chain transfer of mercury in the vicinity of the Nyanza site, Sudbury River, Massachusetts

USGS Publications Warehouse

Haines, T.A.; May, T.W.; Finlayson, R.T.; Mierzykowski, S.E.

2003-01-01

The influence of the Nyanza Chemical Waste Dump Superfund Site on the Sudbury River, Massachusetts, was assessed by analysis of sediment, fish prey organisms, and predator fish from four locations in the river system. Whitehall Reservoir is an impoundment upstream of the site, and Reservoir #2 is an impoundment downstream of the site. Cedar Street is a flowing reach upstream of the site, and Sherman Bridge is a flowing reach downstream of the site. Collections of material for analysis were made three times, in May, July, and October. Sediment was analyzed for acid-volatile sulfide (AVS), simultaneously-extracted (SEM) metals (As, Cd, Cr, Hg, Pb, Sb, Zn), and total recoverable Hg. The dominant predatory fish species collected at all sites, largemouth bass (Micropterus salmoides), was analyzed for the same suite of metals as sediment. Analysis of stomach contents of bass identified small fish (yellow perch Perca flavescens, bluegill Lepomis macrochirus, and pumpkinseed Lepomis gibbosus), crayfish, and dragonfly larvae as the dominant prey organisms. Samples of the prey were collected from the same locations and at the same times as predator fish, and were analyzed for total and methyl mercury. Results of AVS and SEM analyses indicated that sediments were not toxic to aquatic invertebrates at any site. The SEM concentrations of As, Cd, and Cr were significantly higher at Reservoir #2 than at the reference sites, and SEM As and Cd were significantly higher at Sherman Bridge than at Cedar St. Sediment total Hg was elevated only at Reservoir #2. Hg was higher at site-influenced locations in all fish species except brown bullhead (Ameiurus nebulosus). Cd was higher in bluegill, black crappie (Pomoxis nigromaculatus), and brown bullhead, and Cr was higher in largemouth bass fillet samples but not in whole-body samples. There were no seasonal differences in sediment or prey organism metals, but some metals in some fish species did vary over time in an inconsistent manner. Predator fish Hg concentration was significantly linearly related to weighted prey organism methyl Hg concentration. Largemouth bass Hg was significantly lower at Reservoir #2 in our study than in previous investigations in 1989 and 1990. High concentrations of inorganic Hg remain in river sediment as a result of operation of the Nyanza site, and fish Hg concentrations in river reaches downstream of the site are elevated compared to upstream reference sites. However, the differences are relatively small and Hg concentrations in largemouth bass from the site-influenced locations are no higher than those from some other, nearby uncontaminated sites. We hypothesize that this results from burial of contaminated sediment with cleaner material, which reduces bioavailability of contaminants and possibly reduces methylation of mercury.

Dietary α-cyclodextrin modifies gut microbiota and reduces fat accumulation in high-fat-diet-fed obese mice.

PubMed

Nihei, Nanako; Okamoto, Hinako; Furune, Takahiro; Ikuta, Naoko; Sasaki, Kengo; Rimbach, Gerald; Yoshikawa, Yutaka; Terao, Keiji

2018-05-07

We investigated the effect of α-cyclodextrin (α-CD) on the bacterial populations of gut microbiota, production of organic acids, and short-chain fatty acids (SCFAs), and lipid metabolism in obese mice induced by feeding a high-fat diet (HFD). Male C57BL/6J mice were assigned to three diet groups: normal diet (ND) (5% [w/w] fat), HFD (35% [w/w] fat), and HFD (35% [w/w] fat) + 5.5% (w/w) α-CD for 16 weeks. Increases in body and epididymal adipose tissue weights were observed in the HFD group compared with the ND group, which were attenuated in the HFD+α-CD group. The supplementation of α-CD increased the total number of bacteria, Bacteroides, Bifidobacterium, and Lactobacillus that were decreased in gut microbiota of mice by feeding the HFD. Importantly, α-CD administration increased the concentrations of lactic acid and SCFAs, such as acetic, propionic, and butyric acids, and decreased glucose concentrations in cecal contents. Furthermore, supplementation of α-CD upregulated the gene expression of peroxisome proliferator-activated receptor (PPAR)γ involved in adipocyte differentiation and PPARα involved in energy expenditure and downregulated that of sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase involved in fatty acid and triglyceride synthesis in adipose tissue. This study revealed that the alteration in gut microbiota and increased production of lactic acid and SCFAs by supplementation of α-CD have beneficial antiobesity effects via modulating the expression of genes related to lipid metabolism, indicating a prebiotic property of α-CD. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Effect of age on immune parameters and the immune response of dogs to vaccines: a cross-sectional study.

PubMed

HogenEsch, Harm; Thompson, Steven; Dunham, Anisa; Ceddia, Michael; Hayek, Michael

2004-01-01

The evaluation of anti-aging intervention strategies in dogs would benefit from reliable quantitative biomarkers of aging. In the present study, the expression of various immune parameters was measured in young and old dogs to identify potential biomarkers of aging. The second goal of the study was to determine the effect of age on the immune response to vaccines. The immune function, including the antibody response to vaccines, was determined in 32 young adult (3.15+/-0.8 years of age) and 33 old dogs (12.1+/-1.3 years of age) of various breeds. Old dogs had a significantly lower lymphocyte proliferative response and a lower percentage of CD4+ T cells and CD45R+/CD4+ T cells, and a higher percentage of CD8+ T cells and a higher concentration of serum and salivary IgA. The most significant differences (P<0.001) occurred in the lymphocyte proliferative responses to ConA and PHA, the CD4:CD8 ratio, and the percentage of CD45R+/CD4+ T cells suggesting that these parameters are potential biomarkers of aging. There was no difference in the percentage of total T and B lymphocytes and the concentration of serum IgM and IgG. Both groups of dogs had protective titers against distemper virus, parvovirus and rabies virus before annual revaccination. The pre-vaccination titer against rabies virus was higher in the old dogs than in the young dogs, and there were no differences in post-vaccination titers against any of the viruses. This suggests that annual vaccination protocols provide adequate protection for old dogs.

Evaluating cadmium bioavailability in contaminated rice paddy soils and assessing potential for contaminant immobilisation with biochar.

PubMed

Kosolsaksakul, Peerapat; Oliver, Ian W; Graham, Margaret C

2018-06-01

Cadmium (Cd) contaminated soils from the Mae Sot district in northwest Thailand, a region in which rice Cd concentrations often exceed health limits (0.4 mg/kg) set by the World Health Organisation, were examined for isotopically exchangeable Cd (Cd E values using a 111 Cd spike) to determine how this rates as a predictor of rice grain Cd in comparison with soil total Cd and solution extractable Cd (using the commonly applied BCR scheme and, in an attempt to distinguish carbonate bound forms, the Tessier soil sequential extraction scheme reagents). Step 1 of the BCR scheme (0.11 M CH 3 COOH) and step 1 of the Tessier scheme (1M MgCl 2 ) showed the highest R 2 values in regressions with rice Cd (91% and 90%, respectively), but all predictors were strongly linked to rice Cd (p < 0.001) and could be used for prediction purposes. One soil, of the six tested, was an exception to this, where all predictors over-estimated grain Cd by a factor of 2.5-5.7, suggesting that rice grain Cd had been restricted here by the differing flooding regime and subsequent changes to redox conditions. E values and Tessier step 1 extractions were closely related, indicating that these measurements access similar pools of soil Cd. Separately, the isotopic exchangeability (representing bioavailability) of Cd was also assessed in two soils amended with rice husk and miscanthus biochars (0, 1, 5, 10, 15 and 20% w/w) in order to assess the utility of the biochars as a soil amendment for immobilising Cd in situ. One soil showed significant reductions in Cd E value at 5% rice husk biochar addition and at 15% miscanthus biochar addition however, based on the E value-rice grain Cd regression relationship previously established, the E values in the amended soils still predicted for a rice Cd concentration above the health limit. In the second soil, neither of the biochars successfully reduced the Cd E value. This indicates that further work is needed to customise biochar properties to suit specific soil and contaminant situations if they are to be used successfully for remediation of metal contaminated soils. Copyright © 2018 Elsevier Ltd. All rights reserved.

Concentrations and Exposure Evaluation of Metals in Diverse Food Items from Chengdu, China.

PubMed

Wang, Rong; Zhong, Bifeng; Pi, Lu; Xie, Fuyu; Chen, Mengqin; Ding, Sanglan; Su, Shijun; Li, Zhi; Gan, Zhiwei

2018-01-01

A total of 520 food samples belonging to 29 food types and 63 drinking water were collected in Chengdu market of China in 2014 to investigate the concentrations of 11 metals, and to assess the related exposure to the local consumers by estimating the hazard quotient and carcinogenic risk (CR). The results showed that metals concentrations in drinking water were below the limit values suggested by the Ministry of Health of the People's Republic of China, and FAO/WHO (Food and Agriculture Organization of the United Nations/World Health Organization). While As, Cd, and Cr were found at concentrations higher than the limit values in some of the foodstuffs. Children in Chengdu intake more metals compared to adults, with the same order of Mn > Zn > Cu > Sr > Cr > Ni > As > Cd > Pb > Co > Sb. Among all of the diverse food, rice, flour, and fish and seafood were the primary sources to intake metals for Chengdu residents. Residents in Chengdu are subjected to both carcinogenic and non-carcinogenic risks based on the calculated HI and CR values, especially for children. Finally, total daily metals intakes for both children and adults were calculated based on the current study and our previous studies, including consumption of food and drinking water and intake of outdoor and indoor dust. Dietary exposure is the predominant exposure route to metals for Chengdu residents, accounting for more than 75.8% of the total daily metals intakes for both children and adults.

Assessment of influences of cooking on cadmium and arsenic bioaccessibility in rice, using an in vitro physiologically-based extraction test.

PubMed

Zhuang, Ping; Zhang, Chaosheng; Li, Yingwen; Zou, Bi; Mo, Hui; Wu, Kejun; Wu, Jingtao; Li, Zhian

2016-12-15

The health risks associated with rice consumption may decrease if consumers use cooking practices which can reduce the bioaccessibility of metal(loid)s. The effects of cooking on the Cd and As bioaccessibility, at three contamination levels of rice, were studied. Results indicated that cooking reduced bioaccessibility of Cd and As in rice. Cooking resulted in a significant increase (p<0.01) of Cd and As concentrations in the residual fraction. Low volume water-cooking of rice to dryness reduced total Cd by about 10% for rices A and B, while medium or high volume water-cooking had no effect on Cd bioaccessibility in all rice types. In contrast, low volume cooking did not remove As, but a significant decrease (p<0.05) was observed when cooking with higher volumes of water. This study provides information for a better understanding of more realistic estimation of metal(loid)s exposure from rice and the possible health risks. Copyright © 2016. Published by Elsevier Ltd.

Joint toxicity of methamidophos and cadmium acting on Abelmoschus manihot.

PubMed

Wang, Xiao-Fei; Zhou, Qi-Xing

2005-01-01

Joint toxicity of methamidophos and cadmium (Cd) on the ornamental Abelmoschus manihot was firstly examined and compared with single-factor effects of the two pollutants using ecotoxicological indexes including the inhibitory rate of seed germination, root elongation and inhibitory concentration 50% (IC50). The results indicated that methamidophos and Cd had unobvious( p > 0.05) effects on seed germination of the ornamental. There were significant( p < 0.05) inhibitory effects of Cd on root elongation of the tested plant. When the concentration of added Cd was low( < 20 mg/L), significant antagonistic effects on root elongation were observed. And synergic effects were observed when Cd was added in high dose( > 20 mg/L). However, the analysis of joint effects indicated that there were antagonistic effects between Cd and methamidophos under all the treatments. At the high concentration of Cd, joint toxicity of methamidophos and Cd was more dependent on concentration of Cd.

[Evaluation on environmental quality of heavy metals in soils and vegetables based on geostatistics and GIS].

PubMed

Xie, Zheng-miao; Li, Jing; Wang, Bi-ling; Chen, Jian-jun

2006-10-01

Contents of heavy metals (Pb, Zn, Cd, Cu) in soils and vegetables from Dongguan town in Shangyu city, China were studied using geostatistical analysis and GIS technique to evaluate environmental quality. Based on the evaluation criteria, the distribution of the spatial variability of heavy metals in soil-vegetable system was mapped and analyzed. The results showed that the distribution of soil heavy metals in a large number of soil samples in Dongguan town was asymmetric. The contents of Zn and Cu were lower than those of Cd and Pb. The concentrations distribution of Pb, Zn, Cd and Cu in soils and vegetables were different in spatial variability. There was a close relationship between total and available contents of heavy metals in soil. The contents of Pb and Cd in green vegetables were higher than those of Zn and Cu and exceeded the national sanitation standards for vegetables.

Cadmium neurotoxicity to a freshwater planarian.

PubMed

Wu, Jui-Pin; Lee, Hui-Ling; Li, Mei-Hui

2014-11-01

Although freshwater planarians are evolutionarily primitive, they are some of the simplest bilateral animals possessing integrated neural networks similar to those in vertebrates. We attempted to develop planarian Dugesia japonica as a model for investigating the neurotoxicity of environmental pollutants such as cadmium (Cd). This study was therefore designed to study the effects of Cd on the locomotor activity, neurobehavior, and neurological enzymes of D. japonica. After planarians were exposed to Cd at high concentrations, altered neurobehavior was observed that exhibited concentration-dependent patterns. Morphological alterations in Cd-treated planarians included irregular shape, body elongation, screw-like hyperkinesia, and bridge-like position. To study the direct effects of Cd on neurological enzymes, tissue homogenates of planarians were incubated in vitro with Cd before their activity was measured. Results showed that acetylcholinesterase (AChE), adenosine triphosphatase (ATPase), and monoamine oxidase A (MAO-A) activities were inhibited in a concentration-dependent manner. MAO-B activity was significantly induced by Cd at low concentrations and inhibited at high concentrations. Changes in the in vivo activity of AChE and ATPase were also found after planarians were treated with Cd at a sublethal concentration (5.56 μM). These observations indicate that neurotransmission systems in planarians are disturbed after Cd exposure.

Water management practices affect arsenic and cadmium accumulation in rice grains.

PubMed

Sun, Liming; Zheng, Manman; Liu, Hongyan; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

2014-01-01

Cadmium (Cd) and arsenic (As) accumulation in rice grains is a great threat to its productivity, grain quality, and thus human health. Pot and field studies were carried out to unravel the effect of different water management practices (aerobic, aerobic-flooded, and flooded) on Cd and As accumulation in rice grains of two different varieties. In pot experiment, Cd or As was also added into the soil as treatment. Pots without Cd or As addition were maintained as control. Results indicated that water management practices significantly influenced the Cd and As concentration in rice grains and aerobic cultivation of rice furnished less As concentration in its grains. Nonetheless, Cd concentration in this treatment was higher than the grains of flooded rice. Likewise, in field study, aerobic and flooded rice cultivation recorded higher Cd and As concentration, respectively. However, growing of rice in aerobic-flooded conditions decreased the Cd concentration by 9.38 times on average basis as compared to aerobic rice. Furthermore, this treatment showed 28% less As concentration than that recorded in flooded rice cultivation. The results suggested that aerobic-flooded cultivation may be a promising strategy to reduce the Cd and As accumulations in rice grains simultaneously.

[Heavy metal pollution characteristics and ecological risk analysis for soil in Phyllostachys praecox stands of Lin'an].

PubMed

Fang, Xiao-bo; Shi, Han; Liao, Xin-feng; Lou, Zhong; Zhou, Lyu-yan; Yu, Hai-xia; Yao, Lin; Sun, Li-ping

2015-06-01

An investigation was carried out in an attempt to reveal the characteristics of heavy metals contamination in the soils of Phyllostachys praecox forest in Lin' an. Based on the concentrations of Hg, As, Cu, Pb, Zn, Cd, Cr, Ni, Co and Mn in 160 topsoil samples, the pollution status and ecological risks of heavy metals in the soils were assessed by single factor pollution index, Nemerow integrated pollution index and Hankanson potential ecological risk index. The spatial variability of heavy metal concentrations in the soils closely related to the distribution of traffic, industrial and livestock pollution sources. The average concentrations of Hg, As, Cu, Pb, Zn, Cd, Cr, Ni, Co and Mn in the soils were 0.16, 7.41, 34.36, 87.98, 103.98, 0.26, 59.12, 29.56, 11.44 and 350.26 mg · kg(-1), respectively. Pb, Cd, Zn and Cu concentrations were as 2.89, 1.70, 1.12 and 1.12 times as the background values of soil in Zhejiang Province, respectively. But their concentrations were all lower than the threshold values of the National Environmental Quality Standard for Soil (GB 15618-1995). The average single factor pollution index revealed that the level of heavy metal pollution in the soils was in order of Pb>Cd>Cu= Zn>Hg>As>Ni>Co>Cr>Mn. Pb pollution was of moderate level while Cd, Cu and Zn pollutions were slight. There was no soil pollution caused by the other heavy metals. However, the Nemerow integrated pollution index showed that all the 160 soil samples were contaminated by heavy metals to a certain extent. Among total 160 soil samples, slight pollution level, moderate pollution level and heavy pollution level accounted for 55.6%, 29.4% and 15.0%, respectively. The average single factor potential ecological risk index (Er(i)) implied that the potential ecological risk related to Cd reached moderate level, while the others were of slight level. Furthermore, Cd and Hg showed higher potential ecological risk indices which reached up to 256.82 and 187.33 respectively, indicating Cd and Hg had a strong ecological risk and therefore might pose the most serious ecological risk in the soils of P. praecox standsin Lin' an. In addition, the integrated factor potential ecological risk analysis suggested a slight risk to local ecosystem originated from heavy metal contamination in the soils of P. praecox stands in Lin'an.

Atmospheric wet deposition of trace elements to a suburban environment, Reston, Virginia, USA

USGS Publications Warehouse

Conko, Kathryn M.; Rice, Karen C.; Kennedy, Margaret M.

2004-01-01

Wet deposition from a suburban area in Reston, Virginia was collected during 1998 and analyzed to assess the anion and trace-element concentrations and depositions. Suburban Reston, approximately 26 km west of Washington, DC, is densely populated and heavily developed. Wet deposition was collected bi-weekly in an automated collector using trace-element clean sampling and analytical techniques. The annual volume-weighted concentrations of As, Cd, and Pb were similar to those previously reported for a remote site on Catoctin Mt., Maryland (70 km northwest), which indicated a regional signal for these elements. The concentrations and depositions of Cu and Zn at the suburban site were nearly double those at remote sites because of the influence of local vehicular traffic. The 1998 average annual wet deposition (μg m−2 yr−1) was calculated for Al (52,000), As (94), Cd (54), Cr (160), Cu (700), Fe (23,000), Mn (2000), Ni (240), Pb (440), V (430), and Zn (4100). The average annual wet deposition (meq m−2 yr−1) was calculated for H+ (74), Cl− (8.5), NO3− (33), and SO42− (70). Analysis of digested total trace-element concentrations in a subset of samples showed that the refractory elements in suburban precipitation comprised a larger portion of the total deposition of trace elements than in remote areas.

Assessments of levels, potential ecological risk, and human health risk of heavy metals in the soils from a typical county in Shanxi Province, China.

PubMed

Pan, Libo; Ma, Jin; Hu, Yu; Su, Benying; Fang, Guangling; Wang, Yue; Wang, Zhanshan; Wang, Lei; Xiang, Bao

2016-10-01

A total of 128 surface soil samples were collected, and eight heavy metals, including As, Cd, Cr, Cu, Pb, Ni, Zn, and Hg, were analyzed for their concentrations, potential ecological risks, and human health risks. The mean concentrations of these eight metals were lower than the soil environmental quality standards in China, while they were slightly higher than the background values in Shanxi Province. The enrichment factor, coefficient variation, and potential ecological risk index were used to assess the pollution and eco-risk level of heavy metals, among which, Cd and Hg showed higher pollution levels and potential risks than the others in the studied area. Moreover, multivariate geostatistical analysis suggested that Hg originated mainly from point sources such as industrial emissions, while agricultural activity is the predominant factor for Cd. The human health risk assessment indicated that non-carcinogenic values were below the threshold values. The total carcinogenic risks due to As, Cr, and Ni were within the acceptable range for adults, while for children, they were higher than the threshold value (1.0E-04), indicating that children are facing higher threat to heavy metals in soils. These results provide basic information on heavy metal pollution control and human health risk assessment management in the study regions.

Accumulation of Cd, Cu and Zn in shoots of maize (Zea mays L.) exposed to 0.8 or 20 nM Cd during vegetative growth and the relation with xylem sap composition.

PubMed

Nguyen, C; Soulier, A J; Masson, P; Bussière, S; Cornu, J Y

2016-02-01

This work focuses on the exposure of maize plants to nanomolar concentrations of Cd, which is relevant for agricultural soils cropped with food and feed plants. Maize plants were cultivated in nutrient solution at 0.8 or 20 nM Cd during the vegetative growth stages. No significant hormesis or toxic effects of Cd were observed on maize growth, but a decrease in the allocation of Cd to shoots between the 0.8 and 20 nM Cd exposures revealed that the plants already responded to these low concentrations of Cd according to a shoot Cd excluder strategy. The Cd, Cu and Zn concentrations in shoots decreased with time as the result of an early decrease in the root/shoot ratio and of a decrease in the coefficient of allocation to aboveground for Zn and Cd at 20 nM. As a consequence, shoots of young plants were richer in micronutrients Cu and Zn but also in toxic Cd. The rate of delivery of Cd, Cu and Zn from xylem sap was successfully used to predict the time course of concentrations of Cd, Cu and Zn in the shoot. However, it overestimated the actual concentrations of Cd in the shoot, presumably because the reallocation of this trace element from shoots back to roots was not taken into account.

Dietary assimilation of cadmium associated with bacterial exopolymer sediment coatings by the estuarine amphipod Leptocheirus plumulosus: Effects of Cd concentration and salinity

USGS Publications Warehouse

Schlekat, C.E.; Decho, Alan W.; Chandler, G.T.

1999-01-01

Bacterial extracellular substances (also known as exopolysaccharides, or EPS) may serve as vectors for trophic transfer of metals in benthic systems because these ubiquitous sediment coatings can sorb high concentrations of toxic metals, and because many benthic invertebrates assimilate EPS sediment coatings upon ingestion. We conducted 3 sets of experiments to determine the assimilative bioavailability of EPS-associated Cd to the benthic amphipod Leptocheirus plumulosus as a function of Cd concentration and salinity. Bioavailability was measured as L. plumulosus Cd assimilation efficiency (AE) from EPS-coated silica (EPS-Si) and from uncoated silica (NC-Si) using modified pulse-chase methods with the gamma-emitting radioisotope 109Cd. Cd AE was significantly greater from NC-Si than from EPS-Si at 7.5???, but not at 2.5 or 25???. Overall, Cd AE from EPS-Si was between 15.1 and 21.5%. Because EPS-Si sorbed more Cd than NC-Si, EPS coatings magnified the amount of Cd amphipods accumulated at each salinity by up to a factor of 10. Salinity did not directly affect Cd AE from EPS-Si, but because Cd-EPS partitioning increased with decreasing salinity, amphipods accumulated more Cd from EPS at the lowest Cd-EPS incubation salinity (2.5 ???) than at higher salinities (7.5 and 25 ???). Finally, Cd concentration in EPS exhibited an inverse relationship with Cd AE at 2.5 ???, but not at 25 ???. Specifically, Cd AE was 12 times greater at 1 compared with 10 ??g Cd ??g-1 EPS. Together, these results show that estuarine benthos can accumulate Cd from EPS sediment coatings, but that the degree to which this phenomenon occurs is dependent upon seawater salinity and Cd concentration in EPS.

Determination of the total cadmium, copper, lead and zinc concentrations and their labile species fraction in apple beverages by flow-through anodic stripping chronopotentiometry.

PubMed

Jedryczko, Dominika; Pohl, Paweł; Welna, Maja

2017-06-15

An analytical procedure for operationally defined speciation of Cd, Cu, Pb and Zn in apple beverages by anodic stripping chronopotentiometry (ASCP) is presented. Optimal measurement conditions were set down to reliably determine the fraction of the labile metals species. The mean total concentrations of Cu, Pb and Zn were 69±20, 7.3±3.3, and 129±59μgL -1 in apple juices, and 18±3, 4.2±0.1, 53±5μgL -1 in apple drinks, respectively. The contributions of the fraction of the ASCP-labile species varied from 43 to 63% (Cu), from 32 to 42% (Pb) and from 38 to 58% (Zn). The Cd content in all analyzed samples was below 0.02μgL -1 . The detection limits (DLs) achieved for Cu, Pb and Zn were 0.04μgL -1 (Cu), 0.02μgL -1 (Pb), and 0.10μgL -1 (Zn). Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical speciation of trace metals in the industrial sludge of Dhaka City, Bangladesh.

PubMed

Islam, Md Saiful; Al-Mamun, Md Habibullah; Feng, Ye; Tokumura, Masahiro; Masunaga, Shigeki

2017-07-01

The objective of this study was to assess total concentration and chemical fractionation of trace metals in the industrial wastewater and sludge collected from seven different types of industries in Dhaka City, Bangladesh. The sludge from industries is either dumped on landfills or reused as secondary resources in order to preserve natural resources. Metals were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd, and Pb in the sludges were 1.4-9,470, 4.8-994, 12.8-444, 2.2-224, 1.9-46.0 and 1.3-87.0 mg/kg, respectively. As a whole, the average concentrations of trace metals in samples were in the decreasing order of Cr > Ni > Cu > As > Pb > Cd. The results of the Community Bureau of Reference (BCR) sequential extraction showed that the studied metals were predominantly associated with the residual fraction followed by the oxidizable fraction. The study revealed that the mobile fractions of trace metals are poorly predictable from the total content, and bioavailability of all fractions of elements tends to decrease.

Characterization of Photochemical Processes for H2 Production by CdS Nanorod-[FeFe] Hydrogenase Complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, K. A.; Wilker, M. B.; Boehm, M.

2012-03-28

We have developed complexes of CdS nanorods capped with 3-mercaptopropionic acid (MPA) and Clostridium acetobutylicum [FeFe]-hydrogenase I (CaI) that photocatalyze reduction of H{sup +} to H{sub 2} at a CaI turnover frequency of 380-900 s{sup -1} and photon conversion efficiencies of up to 20% under illumination at 405 nm. In this paper, we focus on the compositional and mechanistic aspects of CdS:CaI complexes that control the photochemical conversion of solar energy into H{sub 2}. Self-assembly of CdS with CaI was driven by electrostatics, demonstrated as the inhibition of ferredoxin-mediated H{sub 2} evolution by CaI. Production of H{sub 2} by CdS:CaImore » was observed only under illumination and only in the presence of a sacrificial donor. We explored the effects of the CdS:CaI molar ratio, sacrificial donor concentration, and light intensity on photocatalytic H{sub 2} production, which were interpreted on the basis of contributions to electron transfer, hole transfer, or rate of photon absorption, respectively. Each parameter was found to have pronounced effects on the CdS:CaI photocatalytic activity. Specifically, we found that under 405 nm light at an intensity equivalent to total AM 1.5 solar flux, H{sub 2} production was limited by the rate of photon absorption ({approx}1 ms{sup -1}) and not by the turnover of CaI. Complexes were capable of H{sub 2} production for up to 4 h with a total turnover number of 106 before photocatalytic activity was lost. This loss correlated with inactivation of CaI, resulting from the photo-oxidation of the CdS capping ligand MPA.« less

Clinical Evaluation of the BD FACSPresto™ Near-Patient CD4 Counter in Kenya

PubMed Central

Angira, Francis; Akoth, Benta; Omolo, Paul; Opollo, Valarie; Bornheimer, Scott; Judge, Kevin; Tilahun, Henok; Lu, Beverly; Omana-Zapata, Imelda; Zeh, Clement

2016-01-01

Background The BD FACSPresto™ Near-Patient CD4 Counter was developed to expand HIV/AIDS management in resource-limited settings. It measures absolute CD4 counts (AbsCD4), percent CD4 (%CD4), and hemoglobin (Hb) from a single drop of capillary or venous blood in approximately 23 minutes, with throughput of 10 samples per hour. We assessed the performance of the BD FACSPresto system, evaluating accuracy, stability, linearity, precision, and reference intervals using capillary and venous blood at KEMRI/CDC HIV-research laboratory, Kisumu, Kenya, and precision and linearity at BD Biosciences, California, USA. Methods For accuracy, venous samples were tested using the BD FACSCalibur™ instrument with BD Tritest™ CD3/CD4/CD45 reagent, BD Trucount™ tubes, and BD Multiset™ software for AbsCD4 and %CD4, and the Sysmex™ KX-21N for Hb. Stability studies evaluated duration of staining (18–120-minute incubation), and effects of venous blood storage <6–24 hours post-draw. A normal cohort was tested for reference intervals. Precision covered multiple days, operators, and instruments. Linearity required mixing two pools of samples, to obtain evenly spaced concentrations for AbsCD4, total lymphocytes, and Hb. Results AbsCD4 and %CD4 venous/capillary (N = 189/ N = 162) accuracy results gave Deming regression slopes within 0.97–1.03 and R2 ≥0.96. For Hb, Deming regression results were R2 ≥0.94 and slope ≥0.94 for both venous and capillary samples. Stability varied within 10% 2 hours after staining and for venous blood stored less than 24 hours. Reference intervals results showed that gender—but not age—differences were statistically significant (p<0.05). Precision results had <3.5% coefficient of variation for AbsCD4, %CD4, and Hb, except for low AbsCD4 samples (<6.8%). Linearity was 42–4,897 cells/μL for AbsCD4, 182–11,704 cells/μL for total lymphocytes, and 2–24 g/dL for Hb. Conclusions The BD FACSPresto system provides accurate, precise clinical results for capillary or venous blood samples and is suitable for near-patient CD4 testing. Trial Registration ClinicalTrials.gov NCT02396355 PMID:27483008

Bone metabolism of male rats chronically exposed to cadmium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brzoska, Malgorzata M.; Moniuszko-Jakoniuk, Janina

2005-09-15

Recently, based on a female rat model of human exposure, we have reported that low-level chronic exposure to cadmium (Cd) has an injurious effect on the skeleton. The purpose of the current study was to investigate whether the exposure may also affect bone metabolism in a male rat model and to estimate the gender-related differences in the bone effect of Cd. Young male Wistar rats received drinking water containing 0, 1, 5, or 50 mg Cd/l for 12 months. The bone effect of Cd was evaluated using bone densitometry and biochemical markers of bone turnover. Renal handling of calcium (Ca)more » and phosphate, and serum concentrations of vitamin D metabolites, calcitonin, and parathormone were estimated as well. At treatment with 1 mg Cd/l, corresponding to the low environmental exposure in non-Cd-polluted areas, the bone mineral content (BMC) and density (BMD) at the femur and lumbar spine (L1-L5) and the total skeleton BMD did not differ compared to control. However, from the 6th month of the exposure, the Z score BMD indicated osteopenia in some animals and after 12 months the bone resorption very clearly tended to an increase. The rats' exposure corresponding to human moderate (5 mg Cd/l) and especially relatively high (50 mg Cd/l) exposure dose- and duration-dependently disturbed the processes of bone turnover and bone mass accumulation leading to formation of less dense than normal bone tissue. The effects were accompanied by changes in the serum concentration of calciotropic hormones and disorders in Ca and phosphate metabolism. It can be concluded that low environmental exposure to Cd may be only a subtle risk factor for skeletal demineralization in men. The results together with our previous findings based on an analogous model using female rats give clear evidence that males are less vulnerable to the bone effects of Cd compared to females.« less

Evaluation of treatment outcomes for patients on first-line regimens in US President's Emergency Plan for AIDS Relief (PEPFAR) clinics in Uganda: predictors of virological and immunological response from RV288 analyses.

PubMed

Crawford, K W; Wakabi, S; Magala, F; Kibuuka, H; Liu, M; Hamm, T E

2015-02-01

Viral load (VL) monitoring is recommended, but seldom performed, in resource-constrained countries. RV288 is a US President's Emergency Plan for AIDS Relief (PEPFAR) basic programme evaluation to determine the proportion of patients on treatment who are virologically suppressed and to identify predictors of virological suppression and recovery of CD4 cell count. Analyses from Uganda are presented here. In this cross-sectional, observational study, patients on first-line antiretroviral therapy (ART) (efavirenz or nevirapine+zidovudine/lamivudine) from Kayunga District Hospital and Kagulamira Health Center were randomly selected for a study visit that included determination of viral load (HIV-1 RNA), CD4 cell count and clinical chemistry tests. Subjects were recruited by time on treatment: 6-12, 13-24 or >24 months. Logistic regression modelling identified predictors of virological suppression. Linear regression modelling identified predictors of CD4 cell count recovery on ART. We found that 85.2% of 325 subjects were virologically suppressed (viral load<47 HIV-1 RNA copies/ml). There was no difference in the proportion of virologically suppressed subjects by time on treatment, yet CD4 counts were higher in each successive stratum. Women had higher median CD4 counts than men overall (406 vs. 294 cells/μL, respectively; P<0.0001) and in each time-on-treatment stratum. In a multivariate logistic regression model, predictors of virological suppression included efavirenz use [odds ratio (OR) 0.47; 95% confidence interval (CI) 0.22-1.02; P=0.057], lower cost of clinic visits (OR 0.815; 95% CI 0.66-1.00; P=0.05), improvement in CD4 percentage (OR 1.06; 95% CI 1.014-1.107; P=0.009), and care at Kayunga vs. Kangulamira (OR 0.47; 95% CI 0.23-0.92; P=0.035). In a multivariate linear regression model of covariates associated with CD4 count recovery, time on highly active antiretroviral therapy (ART) (P<0.0001), patient satisfaction with care (P=0.038), improvements in total lymphocyte count (P<0.0001) and haemoglobin concentration (P=0.05) were positively associated, whereas age at start of ART (P=0.0045) was negatively associated with this outcome. High virological suppression rates are achievable on first-line ART in Uganda. The odds of virological suppression were positively associated with efavirenz use and improvements in CD4 cell percentage and total lymphocyte count and negatively associated with the cost of travel to the clinic. CD4 cell reconstitution was positively associated with CD4 count at study visit, time on ART, satisfaction with care at clinic, haemoglobin concentration and total lymphocyte count and negatively associated with age. © 2014 British HIV Association.

Heavy metals in soils and sediments from Dongting Lake in China: occurrence, sources, and spatial distribution by multivariate statistical analysis.

PubMed

Zhang, Yaxin; Tian, Ye; Shen, Maocai; Zeng, Guangming

2018-05-01

Heavy metal contamination in soils/sediments and its impact on human health and ecological environment have aroused wide concerns. Our study investigated 30 samples of soils and sediments around Dongting Lake to analyze the concentration of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in the samples and to distinguish the natural and anthropogenic sources. Also, the relationship between heavy metals and the physicochemical properties of samples was studied by multivariate statistical analysis. Concentration of Cd at most sampling sites were more than five times that of national environmental quality standard for soil in China (GB 15618-1995), and Pb and Zn levels exceeded one to two times. Moreover, Cr in the soil was higher than the national environmental quality standards for one to two times while in sediment was lower than the national standard. The investigation revealed that the accumulations of As, Cd, Mn, and Pb in the soils, and sediments were affected apparently by anthropogenic activities; however, Cr, Fe, and Ni levels were impacted by parent materials. Human activities around Dongting Lake mainly consisted of industrial activities, mining and smelting, sewage discharges, fossil fuel combustion, and agricultural chemicals. The spatial distribution of heavy metal in soil followed the rule of geographical gradient, whereas in sediments, it was significantly affected by the river basins and human activities. The result of principal component analysis (PCA) demonstrated that heavy metals in soils were associated with pH and total phosphorus (TP), while in sediments, As, Cr, Fe, and Ni were closely associated with cation exchange capacity (CEC) and pH, where Pb, Zn, and Cd were associated with total nitrogen (TN), TP, total carbon (TC), moisture content (MC), soil organic matter (SOM), and ignition lost (IL). Our research provides comprehensive approaches to better understand the potential sources and the fate of contaminants in lakeshore soils and sediments.

Spatial variation of acid-volatile sulfide and simultaneously extracted metals in Egyptian Mediterranean Sea lagoon sediments.

PubMed

Younis, Alaa M; El-Zokm, Gehan M; Okbah, Mohamed A

2014-06-01

In risk assessment of aquatic sediments, the immobilizing effect of acid-volatile sulfide (AVS) on trace metals is a principal control on availability and associated toxicity of metals to aquatic biota, which reduces metal bioavailability and toxicity by binding and immobilizing metals as insoluble sulfides. Spatial variation pattern of AVS, simultaneously extracted metals (SEM), and sediment characteristics were studied for the first time in surface sediment samples (0-20 cm) from 43 locations in Egyptian northern delta lagoons (Manzalah, Burullus, and Maryut) as predictors of the bioavailability of some divalent metals (Cu, Zn, Cd, Pb, and Ni) in sediments as well as indicators of metal toxicity in anaerobic sediments. The results indicated that the ∑SEM (Cu + Zn + Cd + Pb + Ni) values in sediments of lagoon Burullus had higher concentrations than those of Maryut and Manzalah. In contrast, AVS concentrations were considerably higher in lagoons Manzalah and Maryut and seemed to be consistent with the increase in organic matter than lagoon Burullus. Generally, the average concentrations of the SEM in all lagoons were in the order of Zn > Cu > Ni > Pb > Cd. The ratios of ∑SEM/AVS were less than 1 at all the sampling stations except at one station in lagoon Maryut as well as four stations located in lagoon Burullus (∑SEM/AVS > 1), which suggests that the metals have toxicity potential in these sediments. Therefore, SEM concentrations probably are better indicators of the metal bioavailability in sediments than the conventional total metal concentrations.

The use of a physiologically-based extraction test to assess relationships between bioaccessible metals in urban soil and neurodevelopmental conditions in children.

PubMed

Hong, Jie; Wang, Yinding; McDermott, Suzanne; Cai, Bo; Aelion, C Marjorie; Lead, Jamie

2016-05-01

Intellectual disability (ID) and cerebral palsy (CP) are serious neurodevelopment conditions and low birth weight (LBW) is correlated with both ID and CP. The actual causes and mechanisms for each of these child outcomes are not well understood. In this study, the relationship between bioaccessible metal concentrations in urban soil and these child conditions were investigated. A physiologically based extraction test (PBET) mimicking gastric and intestinal processes was applied to measure the bio-accessibility of four metals (cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb)) in urban soil, and a Bayesian Kriging method was used to estimate metal concentrations in geocoded maternal residential sites. The results showed that bioaccessible metal concentrations of Cd, Ni, and Pb in the intestinal phase were statistically significantly associated with the child outcomes. Lead and nickel were associated with ID, lead and cadmium was associated with LBW, and cadmium was associated with CP. The total concentrations and stomach concentrations were not correlated to significant effects in any of the analyses. For lead, an estimated threshold value was found that was statistically significant in predicting low birth weight. The change point test was statistically significant (p value = 0.045) at an intestine threshold level of 9.2 mg/kg (95% confidence interval 8.9-9.4, p value = 0.0016), which corresponds to 130.6 mg/kg of total Pb concentration in the soil. This is a narrow confidence interval for an important relationship. Published by Elsevier Ltd.

Cholinesterase activity in the cup oyster Saccostrea sp. exposed to chlorpyrifos, imidacloprid, cadmium and copper.

PubMed

Moncaleano-Niño, Angela M; Luna-Acosta, Andrea; Gómez-Cubillos, Maria Camila; Villamil, Luisa; Ahrens, Michael J

2018-04-30

In the present study, the sensitivity and concentration dependence of three functionally-defined components of cholinesterase activity (total: T-ChE; eserine-sensitive: Es-ChE; and eserine-resistant: Er-ChE) were quantified in the gill, digestive gland and adductor muscle of the tropical cup oyster Saccostrea sp., following acute (96h) aqueous exposure to commercial formulations of the organophosphate (OP) insecticide chlorpyrifos and the neonicotinoid (NN) imidacloprid (concentration range: 0.1-100mg/L), as well as to dissolved cadmium and copper (concentration range: 1-1000μg/L). Oysters (1.5-5.0cm shell length), field-collected from a boating marina in Santa Marta, Colombia (Caribbean Sea) were exposed in the laboratory to each substance at five concentrations. T-ChE, Es-ChE, and Er-ChE activity were quantified in the three tissues in pools of 5 individuals (3 replicates per concentration), before and after inhibition with the total cholinesterase inhibitor eserine (physostigmine, 100µM). Oysters exposed to chlorpyrifos, imidacloprid and Cd showed reduced T-ChE and Es-ChE activity in gills at highest exposure concentrations, with Es-ChE activity being inhibited proportionally more so than T-ChE, whereas Er-ChE activity showed no significant concentration-response. Digestive gland also showed diminished T-ChE, Es-ChE and Er-ChE activity for highest chlorpyrifos and Cd concentrations relative to controls, but an increase of T-ChE and Er-ChE activity at the highest imidacloprid concentration (100mg/L). For Cu, T-ChE, Es-ChE and Er-ChE activities in gills and digestive gland were elevated relative to controls in oysters exposed to Cu concentrations > 100µg/L. In adductor muscle, T-ChE, Es-ChE and Er-ChE activity showed no apparent pattern for any of the four xenobiotics and concentration levels tested. Although this study confirms acute (96h) concentration-dependent reduction of tissue T-ChE and Es-ChE activity in gills and digestive glands of Saccostrea sp. exposed to high concentrations of chlorpyrifos (100mg/L), significant changes in T-ChE, Es-ChE and Er-ChE were also caused by exposure to Cd and Cu at concentrations > 100µg/L and by exposure to imidacloprid (100mg/L), indicating that cholinesterase activity is not a specific biomarker of organophosphate exposure in this species, but, rather, a biomarker of diverse xenobiotic exposure. Copyright © 2018 Elsevier Inc. All rights reserved.

Reactive oxygen species metabolism during the cadmium hyperaccumulation of a new hyperaccumulator Sedum alfredii (Crassulaceae).

PubMed

Zhang, Zhong-chun; Qiu, Bao-Sheng

2007-01-01

Sedum alfredii Hance, a newly discovered hyperaccumulator, could serve as a good material for phytoremediation of Cd polluted sites. Malondialdehyde (MDA), reactive oxygen species (ROS) and antioxidases (catalase (CAT); superoxide dismutase (SOD); peroxidase (POD)) in the leaf were determined when S. alfredii was treated for 15 d with various CdCl2 concentrations ranging from 0 to 800 micromol/L. The results showed that the production rate of 2',7'-dichlorofluorescein (DCF), which is an indicator of ROS level, reached up to the maximum at 400 micromol/L CdCl2 and then declined with the increase of CdCl2 concentration, while MDA accumulation tended to increase. CAT activity was significantly inhibited at all tested CdCl2 concentrations and SOD activity was sharply suppressed at 800 micromol/L CdCl2. However, the enhancement of POD activity was observed when CdCl2 concentration was higher than 400 micromol/L. In addition, its activity increased when treated with 600 micromol/L CdCl2 for more than 5 d. When sodium benzoate, a free radical scavenger, was added, S. alfredii was a little more sensitive to Cd toxicity than that exposed to Cd alone, and the Cd accumulation tended to decline with the increase of sodium benzoate concentration. It came to the conclusions that POD played an important role during Cd hyperaccumulation, and the accumulation of ROS induced by Cd treatment might be involved in Cd hyperaccumulation.

Association of lead, cadmium and mercury with paraoxonase 1 activity and malondialdehyde in a general population in Southern Brazil.

PubMed

Almeida Lopes, Ana Carolina Bertinde; Urbano, Mariana Ragassi; Souza-Nogueira, André de; Oliveira-Paula, Gustavo H; Michelin, Ana Paula; Carvalho, Maria de Fátima H; Camargo, Alissana Ester Iakmiu; Peixe, Tiago Severo; Cabrera, Marcos Aparecido Sarria; Paoliello, Monica Maria Bastos

2017-07-01

Metal exposure is associated with increased oxidative stress (OS), which is considered an underlying mechanism of metal-induced toxicity. Malondialdehyde (MDA) is a final product of lipid peroxidation, and it has been extensively used to evaluate metal-induced OS. Pro-oxidant effects produced by metals can be mitigated by paraoxonase 1 (PON1), an antioxidant enzyme known to prevent cardiovascular disease and atherosclerosis. Among other factors, the Q192R polymorphism and the exposure to heavy metals have been known to alter PON1 activity. Here, we evaluated the association of blood lead (Pb), cadmium (Cd) and mercury (Hg) levels with PON1 activity, and with MDA concentrations in a randomly selected sample of Brazilian adults aged 40 years or older, living in an urban area in Southern Brazil. A total of 889 subjects were evaluated for blood Pb and Cd levels, and 832 were tested for Hg. Geometric mean of blood Pb, Cd and Hg was 1.93μg/dL, 0.06μg/L and 1.40μg/L, respectively. PON1 activity was significantly different among various genotypes: QQ (PON1=121.4U/mL), QR (PON1=87.5U/mL), and RR (PON1=55.2U/mL), p<0.001. PON1 genotypes were associated only with Cd blood levels. Those with QR genotype had Cd concentrations higher (0.07μg/L) than those with the RR genotype (0.04μg/L) with p=0.034. However, PON1 activity was not significantly associated with metal concentrations. Cluster analysis showed that men who reported to be current smokers and drinkers with higher blood Pb and Cd levels, had significantly lower PON1 activity than non-smokers or -drinkers, and women with lower Pb and Cd levels. RR genotype carriers had lower PON1 activity than those with the QR genotype, and had higher levels of Pb and Cd compared with other genotype carriers. For blood Hg, no association with PON1 activity or genotype was noted. We found low levels of Pb, Cd and Hg in environmentally exposed Brazilian adults. Cd concentrations were increased in subjects with QR genotype. Those with RR genotype had lower PON1 activity and higher levels of Pb and Cd than other genotype carriers. The results of cluster analysis suggested that smoking status exerts a significant influence on PON1 activity. Other studies with environmentally exposed populations are required to further clarify whether low blood levels of metals influence OS biomarkers. Copyright © 2017 Elsevier Inc. All rights reserved.

Pollution in the urban soils of Lianyungang, China, evaluated using a pollution index, mobility of heavy metals, and enzymatic activities.

PubMed

Li, Yu; Li, Hong-Guan; Liu, Fu-Cheng

2017-01-01

Soil samples from 16 urban sites in Lianyungang, China were collected and analyzed. A pollution index was used to assess the potential ecological risk of heavy metals and a sequential extraction procedure was used to evaluate the relative distribution of Cu, Zn, Pb, Cd, Cr, and As in exchangeable, carbonate, Fe/Mn oxide, organic/sulfide, and residual fractions. The mobility of heavy metals and urease (URE) activity, alkaline phosphatase (ALP) activity, and invertase (INV) activity of soils was determined. The results showed that the average concentrations of Cu, Zn, Pb, Cd, Cr, and As in Lianyungang soils were much higher than those in the coastal city soil background values of Jiangsu and China. Among the five studied regions (utilities, commercial, industrial, tourism, and roadside), the industrial region had the highest metal concentrations demonstrating that land use had a significant impact on the accumulation of heavy metals in Lianyungang soils. Compared to the other metals, Cd showed the highest ecological risk. According to chemical partitioning, Cu was associated with the organic/sulfides and Pb and Zn were mainly in the carbonate and the Fe/Mn oxide phase. The greatest amounts of Cd were found in exchangeable and carbonate fractions, while Cr and As were mainly in the residual fraction. Cd had the highest mobility of all metals, and the order of mobility (highest to lowest) of heavy metals in Lianyungang soils was Cd > Zn > Pb > Cu > As > Cr. Soil urease activity, alkaline phosphatase activity, and invertase activity varied considerably in different pollution degree sites. Soil enzyme activities had the lowest levels in roadside and industrial regions. Across all the soil data in the five regions, the total Cu, Zn, Pb, Cd, Cr, and As level was negatively correlated with urease activity, alkaline phosphatase activity, and invertase activity, but the relationship was not significant. In the industrial region, alkaline phosphatase activity had significant negative correlations with total Cu, Pb, Cr, Zn, Cd, and heavy metal fractions. This showed that alkaline phosphatase activity was sensitive to heavy metals in heavily contaminated regions, whereas urease and invertase were less affected. The combination of the various methods may offer a powerful analytical technique in the study of heavy metal pollution in street soil.

Fabrication of CdS nanowires with increasing anionic precursor by SILAR method

NASA Astrophysics Data System (ADS)

Dariani, R. S.; Salehi, F.

2016-05-01

CdS nanowires were fabricated on glass substrate at room temperature by SILAR method with cadmium nitrate cationic and sodium sulfide anionic precursors. The deposition were done at different S:Cd concentration ratios of 1:1, 3:1, 5:1, and 7:1. Nanowires growth procedure was studied in the mentioned concentrations. The number of immersion cycles was kept constant at 15 cycles. EDX analysis showed that in all stoichiometric ratios, S/Cd composition ratio remains at about unity. Our results indicated that S:Cd concentration ratio of 7:1 had the longest nanowires with hexagonal structure. The main objective of this paper was to produce CdS nanowires with increasing concentration of sulfur.

Combining contamination indexes, sediment quality guidelines and multivariate data analysis for metal pollution assessment in marine sediments of Cienfuegos Bay, Cuba.

PubMed

Peña-Icart, Mirella; Pereira-Filho, Edenir Rodrigues; Lopes Fialho, Lucimar; Nóbrega, Joaquim A; Alonso-Hernández, Carlos; Bolaños-Alvarez, Yoelvis; Pomares-Alfonso, Mario S

2017-02-01

The purpose of the present work was to combine several tools for assessing metal pollution in marine sediments from Cienfuegos Bay. Fourteen surface sediments collected in 2013 were evaluated. Concentrations of As, Cu, Ni, Zn and V decreased respect to those previous reported. The metal contamination was spatially distributed in the north and south parts of the bay. According to the contamination factor (CF) enrichment factor (EF) and index of geoaccumulation (I geo ), Cd and Cu were classified in that order as the most contaminated elements in most sediment. Comparison of the total metal concentrations with the threshold (TELs) and probable (PELs) effect levels in sediment quality guidelines suggested a more worrisome situation for Cu, of which concentrations were occasional associated with adverse biological effects in thirteen sediments, followed by Ni in nine sediments; while adverse effects were rarely associated with Cd. Probably, Cu could be considered as the most dangerous in the whole bay because it was classified in the high contamination levels by all indexes and, simultaneously, associated to occasional adverse effects in most samples. Despite the bioavailability was partially evaluated with the HCl method, the low extraction of Ni (<3% in all samples) and Cu (<55%, except sample 3) and the relative high extraction of Cd (50% or more, except sample 14) could be considered as an attenuating (Ni and Cu) or increasing (Cd) factor in the risk assessment of those element. Copyright © 2016. Published by Elsevier Ltd.

Phytoextraction potential of poplar (Populus alba L. var. pyramidalis Bunge) from calcareous agricultural soils contaminated by cadmium.

PubMed

Hu, Yahu; Nan, Zhongren; Jin, Cheng; Wang, Ning; Luo, Huanzhang

2014-01-01

To investigate the phytoextraction potential of Populus alba L. var. pyramidalis Bunge for cadmium (Cd) contaminated calcareous soils, a concentration gradient experiment and a field sampling experiment (involving poplars of different ages) were conducted. The translocation factors for all experiments and treatments were greater than 1. The bioconcentration factor decreased from 2.37 to 0.25 with increasing soil Cd concentration in the concentration gradient experiment and generally decreased with stand age under field conditions. The Cd concentrations in P. pyramidalis organs decreased in the order of leaves > stems > roots. The shoot biomass production in the concentration gradient experiment was not significantly reduced with soil Cd concentrations up to or slightly over 50 mg kg(-1). The results show that the phytoextraction efficiency of P. pyramidalis depends on both the soil Cd concentration and the tree age. Populus pyramidalis is most suitable for remediation of slightly Cd contaminated calcareous soils through the combined harvest of stems and leaves under actual field conditions.

Annual suspended sediment and trace element fluxes in the Mississippi, Columbia, Colorado, and Rio Grande drainage basins

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Smith, J.J.

2001-01-01

Suspended sediment, sediment-associated, total trace element, phosphorus (P), and total organic carbon (TOC) fluxes were determined for the Mississippi, Columbia, Rio Grande, and Colorado Basins for the study period (the 1996, 1997, and 1998 water years) as part of the US Geological Survey's redesigned National Stream Quality Accounting Network (NASQAN) programme. The majority (??? 70%) of Cu, Zn, Cr, Ni, Ba, P, As, Fe, Mn, and Al are transported in association with suspended sediment; Sr transport seems dominated by the dissolved phase, whereas the transport of Li and TOC seems to be divided equally between both phases. Average dissolved trace element levels are markedly lower than reported during the original NASQAN programme; this seems due to the use of 'clean' sampling, processing, and analytical techniques rather than to improvements in water quality. Partitioning between sediment and water for Ag, Pb, Cd, Cr, Co, V, Be, As, Sb, Hg, and Ti could not be estimated due to a lack of detectable dissolved concentrations in most samples. Elevated suspended sediment-associated Zn levels were detected in the Ohio River Basin and elevated Hg levels were detected in the Tennessee River, the former may affect the mainstem Mississippi River, whereas the latter probably do not. Sediment-associated concentrations of Ag, Cu, Pb, Zn, Cd, Cr, Co, Ba, Mo, Sb, Hg, and Fe are markedly elevated in the upper Columbia Basin, and appear to be detectable (Zn, Cd) as far downstream as the middle of the basin. These elevated concentrations seem to result from mining and/or mining-related activities. Consistently detectable concentrations of dissolved Se were found only in the Colorado River Basin. Calculated average annual suspended sediment fluxes at the mouths of the Mississippi and Rio Grande Basins were below, whereas those for the Columbia and Colorado Basins were above previously published annual values. Downstream suspended sediment-associated and total trace element fluxes increase in the Mississippi and Columbia Basins, whereas fluxes markedly decrease in the Colorado Basin. No consistent pattern in trace element fluxes was detected in the Rio Grande Basin.

Effects of various cooking processes on the concentrations of arsenic, cadmium, mercury, and lead in foods.

PubMed

Perelló, Gemma; Martí-Cid, Roser; Llobet, Juan M; Domingo, José L

2008-12-10

The effects of cooking processes commonly used by the population of Catalonia (Spain) on total arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) concentrations in various foodstuffs were investigated. All food samples were randomly acquired in local markets, big supermarkets, and grocery stores of Reus (Catalonia). Foods included fish (sardine, hake, and tuna), meat (veal steak, loin of pork, breast and thigh of chicken, and steak and rib of lamb), string bean, potato, rice, and olive oil. For each food item, two composite samples were prepared for metal analyses, whose levels in raw and cooked (fried, grilled, roasted, and boiled) samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The highest concentrations of As, Hg, and Pb (raw and cooked samples) were mainly found in fish, with a clear tendency, in general, to increase metal concentrations after cooking. However, in these samples, Cd levels were very close to their detection limit. In turn, the concentrations of metals in raw and cooked meat samples were detected in all samples (As) or only in a very few samples (Cd, Hg, and Pb). A similar finding corresponded to string beans, rice, and olive oil, while in potatoes, Hg could not be detected and Pb only was detected in the raw samples. In summary, the results of the present study show that, in general terms, the cooking process is only of a very limited value as a means of reducing metal concentrations. This hypothetical reduction depends upon cooking conditions (time, temperature, and medium of cooking).

Bio fuel ash in a road construction: impact on soil solution chemistry.

PubMed

Thurdin, R T; van Hees, P A W; Bylund, D; Lundström, U S

2006-01-01

Limited natural resources and landfill space, as well as increasing amounts of ash produced from incineration of bio fuel and municipal solid waste, have created a demand for useful applications of ash, of which road construction is one application. Along national road 90, situated about 20 km west of Sollefteå in the middle of Sweden, an experiment road was constructed with a 40 cm bio fuel ash layer. The environmental impact of the ash layer was evaluated from soil solutions obtained by centrifugation of soil samples taken on four occasions during 2001-2003. Soil samples were taken in the ash layer, below the ash layer at two depths in the road and in the ditch. In the soil solutions, pH, conductivity, dissolved organic carbon (DOC) and the total concentration of cations (metals) and anions were determined. Two years after the application of the ash layers in the test road, the concentrations in the ash layer of K, SO4, Zn, and Hg had increased significantly while the concentration of Se, Mo and Cd had decreased significantly. Below the ash layer in the road an initial increase of pH was observed and the concentrations of K, SO4, Se, Mo and Cd increased significantly, while the concentrations of Cu and Hg decreased significantly in the road and also in the ditch. Cd was the element showing a potential risk of contamination of the groundwater. The concentrations of Ca in the ash layer indicated an ongoing hardening, which is important for the leaching rate and the strength of the road construction.

Potential of Ranunculus acris L. for biomonitoring trace element contamination of riverbank soils: photosystem II activity and phenotypic responses for two soil series.

PubMed

Marchand, Lilian; Lamy, Pierre; Bert, Valerie; Quintela-Sabaris, Celestino; Mench, Michel

2016-02-01

Foliar ionome, photosystem II activity, and leaf growth parameters of Ranunculus acris L., a potential biomonitor of trace element (TE) contamination and phytoavailability, were assessed using two riverbank soil series. R. acris was cultivated on two potted soil series obtained by mixing a TE (Cd, Cu, Pb, and Zn)-contaminated technosol with either an uncontaminated sandy riverbank soil (A) or a silty clay one slightly contaminated by TE (B). Trace elements concentrations in the soil-pore water and the leaves, leaf dry weight (DW) yield, total leaf area (TLA), specific leaf area (SLA), and photosystem II activity were measured for both soil series after a 50-day growth period. As soil contamination increased, changes in soluble TE concentrations depended on soil texture. Increase in total soil TE did not affect the leaf DW yield, the TLA, the SLA, and the photosystem II activity of R. acris over the 50-day exposure. The foliar ionome did not reflect the total and soluble TE concentrations in both soil series. Foliar ionome of R. acris was only effective to biomonitor total and soluble soil Na concentrations in both soil series and total and soluble soil Mo concentrations in the soil series B.

Elevated CO2 increases glomalin-related soil protein (GRSP) in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils.

PubMed

Jia, Xia; Zhao, Yonghua; Liu, Tuo; Huang, Shuping; Chang, Yafei

2016-11-01

Glomalin-related soil protein (GRSP), which contains glycoproteins produced by arbuscular mycorrhizal fungi (AMF), as well as non-mycorrhizal-related heat-stable proteins, lipids, and humic materials, is generally categorized into two fractions: easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP). GRSP plays an important role in soil carbon (C) sequestration and can stabilize heavy metals such as lead (Pb), cadmium (Cd), and manganese (Mn). Soil contamination by heavy metals is occurring in conjunction with rising atmospheric CO 2 in natural ecosystems due to human activities. However, the response of GRSP to elevated CO 2 combined with heavy metal contamination has not been widely reported. Here, we investigated the response of GRSP to elevated CO 2 in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils. Elevated CO 2 (700 μmol mol -1 ) significantly increased T- and EE- GRSP concentrations in soils contaminated with Cd, Pb or Cd + Pb. GRSP contributed more carbon to the rhizosphere soil organic carbon pool under elevated CO 2  + heavy metals than under ambient CO 2 . The amount of Cd and Pb bound to GRSP was significantly higher under elevated (compared to ambient) CO 2 ; and elevated CO 2 increased the ratio of GRSP-bound Cd and Pb to total Cd and Pb. However, available Cd and Pb in rhizosphere soil under increased elevated CO 2 compared to ambient CO 2 . The combination of both metals and elevated CO 2 led to a significant increase in available Pb in rhizosphere soil compared to the Pb treatment alone. In conclusion, increased GRSP produced under elevated CO 2 could contribute to sequestration of soil pollutants by adsorption of Cd and Pb. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimal Soil Eh, pH, and Water Management for Simultaneously Minimizing Arsenic and Cadmium Concentrations in Rice Grains.

PubMed

Honma, Toshimitsu; Ohba, Hirotomo; Kaneko-Kadokura, Ayako; Makino, Tomoyuki; Nakamura, Ken; Katou, Hidetaka

2016-04-19

Arsenic (As) and cadmium (Cd) concentrations in rice grains are a human health concern. We conducted field experiments to investigate optimal conditions of Eh and pH in soil for simultaneously decreasing As and Cd accumulation in rice. Water managements in the experiments, which included continuous flooding and intermittent irrigation with different intervals after midseason drainage, exerted striking effects on the dissolved As and Cd concentrations in soil through changes in Eh, pH, and dissolved Fe(II) concentrations in the soil. Intermittent irrigation with three-day flooding and five-day drainage was found to be effective for simultaneously decreasing the accumulation of As and Cd in grain. The grain As and Cd concentrations were, respectively, linearly related to the average dissolved As and Cd concentrations during the 3 weeks after heading. We propose a new indicator for expressing the degree to which a decrease in the dissolved As or Cd concentration is compromised by the increase in the other. For minimizing the trade-off relationship between As and Cd in rice grains in the field investigated, water management strategies should target the realization of optimal soil Eh of -73 mV and pH of 6.2 during the 3 weeks after heading.

Water-Chemistry and On-Site Sulfur-Speciation Data for Selected Springs in Yellowstone National Park, Wyoming, 1996-1998

USGS Publications Warehouse

Ball, James W.; Nordstrom, D. Kirk; McCleskey, R. Blaine; Schoonen, Martin A.A.; Xu, Yong

2001-01-01

Fifty-eight water analyses are reported for samples collected from 19 hot springs and their overflow drainages and one ambient-temperature acid stream in Yellowstone National Park (YNP) during 1996-98. These water samples were collected and analyzed as part of research investigations on microbially mediated sulfur oxidation in stream waters and sulfur redox speciation in hot springs in YNP and chemical changes in overflow drainages that affect major ions, redox species, and trace elements. The research on sulfur redox speciation in hot springs is a collaboration with the State University of New York at Stony Brook, Northern Arizona University, and the U.S. Geological Survey (USGS). One ambient-temperature acidic stream system, Alluvium Creek and its tributaries in Brimstone Basin, was studied in detail. Analyses were performed adjacent to the sampling site, in an on-site mobile laboratory truck, or later in a USGS laboratory, depending on stability and preservability of the constituent. Water temperature, specific conductance, pH, Eh, dissolved oxygen (D.O.), and dissolved H2S were determined on-site at the time of sampling. Alkalinity and F were determined within a few days of sample collection by titration and by ion-selective electrode, respectively. Concentrations of S2O3 and SxO6 were determined as soon as possible (minutes to hours later) by ion chromatography (IC). Concentrations of Cl, SO4, and Br were determined by IC within a few days of sample collection. Concentrations of Fe(II) and Fe(total) were determined by ultraviolet/visible spectrophotometry within a few days of sample collection. Densities were determined later in the USGS laboratory. Concentrations of Li, Na, and K were determined by flame atomic absorption (Li) and emission (Na, K) spectrometry. Concentrations of Al, As(total), B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe(total), Mg, Mn, Ni, Pb, Si, Sr, V, and Zn were determined by inductively-coupled plasma optical emission spectrometry. Trace concentrations of Cd, Se, As(total), Ni, and Pb were determined by Zeeman-corrected graphite-furnace atomic-absorption spectrometry. Trace concentrations of As(total) and As(III) were determined by hydride generation using a flow-injection analysis system.

The Form of Choline in the Maternal Diet Affects Immune Development in Suckled Rat Offspring.

PubMed

Lewis, Erin D; Richard, Caroline; Goruk, Susan; Dellschaft, Neele S; Curtis, Jonathan M; Jacobs, René L; Field, Catherine J

2016-04-01

Lipid-soluble phosphatidylcholine (PC) and aqueous free choline are absorbed and metabolized differently, but the metabolic effects of feeding these 2 forms of choline have not been thoroughly investigated. We sought to compare the effects of PC and free choline in the maternal diet on the development of the offspring's immune system. During lactation, Sprague-Dawley dams (n= 10) were randomly assigned to 1 of 2 diet groups containing the same concentration of total choline (1 g/kg diet) as free choline (choline bitartrate) or PC (egg lecithin). The splenocytes of pups aged 21 d were isolated and stimulated ex vivo with concanavalin A (ConA) or lipopolysaccharide (LPS), and the choline concentrations of stomach content, plasma, and the spleen were measured. Pups from PC-fed dams had a lower proportion of cells involved in antigen presentation but produced 54% more interleukin (IL)-2, 163% more IL-6, and 107% more IFN-γ after ConA stimulation and 110% more IL-6 and 43% more tumor necrosis factor (TNF)-α after LPS stimulation (allP< 0.05). The PC concentrations were significantly higher in the plasma and spleen of pups from PC-fed dams (P< 0.05). Increasing the supply of PC in the form of lysophosphatidylcholine to splenocytes in vitro increased the rate of proliferation and IL-2 production and the surface expression of CD25, CD28, CD71, and CD152 on CD8+ T cells, suggesting 1 possible mechanism. The results of this study demonstrate that providing choline to rats in the form of PC (compared to free choline), possibly by increasing the supply of PC to the suckling pups, promotes maturation and improves function of the offspring's immune system. © 2016 American Society for Nutrition.

Multivariate characterization of elements accumulated in King Bolete Boletus edulis mushroom at lowland and high mountain regions.

PubMed

Falandysz, J; Kunito, T; Kubota, R; Bielawski, L; Frankowska, A; Falandysz, Justyna J; Tanabe, S

2008-12-01

Based on ICP-MS, ICP-OES, HG-AAS, CV-AAS and elementary instrumental analysis of King Bolete collected from four sites of different soil bedrock geochemistry considered could be as mushroom abundant in certain elements. King's Bolete fruiting bodies are very rich in K (> 20 mg/g dry weight), rich in Ca, Mg, Na, Rb and Zn (> 100 microg/g dw), and relatively also rich in Ag, Cd, Cs, Cu, Fe, Mn and Se (> 10 microg/g dw). The caps of King Bolete when compared to stipes around two-to three-fold more abundant are in Ag, Cd, Cs, Cu, Hg, K, Mg, Mo, N, Rb, Se and Zn. King Bolete collected at the lowland and mountain sites showed Ag, Ba, Co, Cr, Hg, K, Mg, Mn, Mo and Na in caps in comparable concentrations, and specimens from the mountain areas accumulated more Cd and Sb. Elements such as Al, Pb and Rb occurred at relatively elevated concentration in King Bolete picked up at the metal ores-rich region of the Sudety Mountains. Because of high bioconcentration potential King Bolete at the background sites accumulate in fruiting bodies great concentrations of problematic elements such as Cd, Pb and Hg, i.e. up to nearly 20, 3 and 5 microg/g dw, on the average, respectively. The interdependence among determined mineral elements examined were using the principal components analysis (PCA) method. The PCA explained 56% of the total variance. The metals tend to cluster together (Ba, Cd, Cs, Cr, Ga, Rb, Se, Sr and V; K and Mg; Cu and Mo). The results provided useful environmental and nutritional background level information on 26 minerals as the composition of King Bolete from the sites of different bedrock soil geochemistry.

Trace elements and heavy metals in mineral and bottled drinking waters on the Iranian market.

PubMed

Hadiani, Mohammad Rasoul; Dezfooli-Manesh, Shirin; Shoeibi, Shahram; Ziarati, Parisa; Mousavi Khaneghah, Amin

2015-01-01

A survey of Iranian waters, sampled from 2010 to 2013, is presented. A total of 128 water samples from 42 different brands of bottled mineral and drinking water were collected and analysed for contamination levels of lead (Pb), cadmium (Cd), copper (Cu), arsenic (As) and mercury (Hg). Determinations were performed using a graphite furnace atomic absorption spectrophotometer for Pb, Cd and Cu, a hydride vapour generation as well as an Arsenator digital kit (Wagtech WTD, Tyne and Wear, UK) for As and a direct mercury analyser for Hg. Arsenic concentration in six bottled gaseous mineral samples was higher than the related limit. Regardless of these, mean concentrations of Pb, Cd, Cu, As and Hg in all types of water samples were 4.50 ± 0.49, 1.08 ± 0.09, 16.11 ± 2.77, 5.80 ± 1.63 and 0.52 ± 0.03 µg L⁻¹, respectively. Values obtained for analysed heavy metals in all samples were permissible according to the limits of national and international standards.

Bioaccessibility, dietary exposure and human risk assessment of heavy metals from market vegetables in Hong Kong revealed with an in vitro gastrointestinal model.

PubMed

Hu, Junli; Wu, Fuyong; Wu, Shengchun; Cao, Zhihong; Lin, Xiangui; Wong, Ming Hung

2013-04-01

A systematic survey of heavy metal (HM) concentrations and bioaccessibilities in market vegetables in Hong Kong were carried out for assessing potential health risk to local inhabitants. The average concentrations of Cd, Pb, Cr, Ni, Cu, and Zn in nine major groups of fresh vegetable varied within 0.007-0.053, 0.05-0.17, 0.05-0.24, 0.26-1.1, 0.62-3.0, and 0.96-4.3 mg kg(-1), respectively, and their average bioaccessibilities varied within 21-96%, 20-68%, 24-62%, 29-64%, 30-77%, and 69-94%, respectively. The bioaccessible estimated daily intakes (BEDIs) of Cd, Pb, Cr, Ni, Cu, and Zn from vegetables were far below the tolerable limits. The total bioaccessible target hazard quotient (TBTHQ) of the six HMs was 0.18 and 0.64 for average and high consumers, respectively, with Cd and leafy vegetable being the major risk contributors. Risk assessment of HMs from foods should be modified by taking bioaccessibility into account. Copyright © 2012 Elsevier Ltd. All rights reserved.

Conventional crops and organic amendments for Pb, Cd and Zn treatment at a severely contaminated site.

PubMed

Pichtel, J; Bradway, D J

2008-03-01

The ability of selected plants and amendments to treat Pb, Cd and Zn accumulations from a metalliferous waste disposal site was studied both in the greenhouse and field. Spinach (Spinacea oleracea), cabbage (Brassica oleracea), and a grass-legume mix (red fescue, Festuca rubra; ryegrass, Lolium perenne); and bean (Vicia faba) were grown in the greenhouse on blast furnace slag or baghouse dust amended with composted peat (CP). All plant species accumulated Pb, Cd and Zn to varying degrees. Total soil metal concentrations had a marked influence on plant uptake. Topdressing versus incorporating CP had a significant (p<0.05) effect on spinach and cabbage tissue metal concentrations. Soil Pb and Zn tended to shift towards less bioavailable forms after treatment with CP. Field plots were treated with CP, farmyard manure (FYM), or inorganic fertilizer. Dry matter production of spinach, cabbage and a grass-legume mix was greatest on either the CP or FYM treatments. Phytostabilization in combination with organic amendments may be the most appropriate technology to ensure stabilization of soil metals at this site.

Total Contents and Sequential Extraction of Heavy Metals in Soils Irrigated with Wastewater, Akaki, Ethiopia

NASA Astrophysics Data System (ADS)

Fitamo, Daniel; Itana, Fisseha; Olsson, Mats

2007-02-01

The Akaki River, laden with untreated wastes from domestic, industrial, and commercial sources, serves as a source of water for irrigating vegetable farms. The purpose of this study is to identify the impact of waste-water irrigation on the level of heavy metals and to predict their potential mobility and bioavailability. Zn and V had the highest, whereas Hg the lowest, concentrations observed in the soils. The average contents of As, Co, Cr, Cu, Ni, Zn, V, and Hg of both soils; and Pb and Se from Fluvisol surpassed the mean + 2 SD of the corresponding levels reported for their uncontaminated counterparts. Apparently, irrigation with waste water for the last few decades has contributed to the observed higher concentrations of the above elements in the study soils (Vertisol and Fluvisol) when compared to uncontaminated Vertisol and Fluvisol. On the other hand, Vertisol accommodated comparatively higher average levels of Cr, Cu, Ni, Zn, etc V, and Cd, whereas high contents of Pb and Se were observed in Fluvisol. Alternatively, comparable levels of Co and Hg were found in either soil. Except for Ni, Cr, and Cd in contaminated Vertisol, heavy metals in the soils were not significantly affected by the depth (0-20 and 30-50 cm). When the same element from the two soils was compared, the levels of Cr, Cu, Ni, Pb, Se, Zn, V, Cd at 0-20 cm; and Cr, Ni, Cu, Cd, and Zn at 30-50 cm were significantly different. Organic carbon (in both soils), CEC (Fluvisol), and clay (Vertisol) exhibited significant positive correspondences with the total heavy metal levels. Conversely, Se and Hg contents revealed perceptible associations with carbonate and pH. The exchangeable fraction was dominated by Hg and Cd, whereas the carbonate fraction was abounded with Cd, Pb, and Co. conversely, V and Pb displayed strong affinity to reducible fraction, where as Cr, Cu, Zn, and Ni dominated the oxidizable fraction. Cr, Hg, Se, and Zn (in both soils) showed preference to the residual fraction. Generally, a considerable proportion of the total levels of many of the heavy metals resided in non residual fractions. The enhanced lability is generally expected to follow the order: Cd > Co > Pb > Cu > Ni > Se > V and Pb > Cd > Co > Cu > Ni > Zn in Vertisol and Fluvisol, respectively. For the similar wastewater application, the soil variables influence the status and the distribution of the associated heavy metals among the different soil fractions in the study soils. Among heavy metals that presented relatively elevated levels and with potential mobility, Co, Cu, Ni (either soil), V (Vertisol), Pb, and Zn (Fluvisol) could pose health threat through their introduction into the food chain in the wastewater irrigated soils.

The Role of Node Restriction on Cadmium Accumulation in the Brown Rice of 12 Chinese Rice (Oryza sativa L.) Cultivars.

PubMed

Huang, Gaoxiang; Ding, Changfeng; Guo, Fuyu; Li, Xiaogang; Zhou, Zhigao; Zhang, Taolin; Wang, Xingxiang

2017-11-29

For selection or breeding of rice (Oryza sativa L.) cultivars with low Cd affinity, the role of node Cd restriction on Cd accumulation in brown rice was studied. A pot experiment was conducted to investigate the concentration of Cd in different sections of 12 Chinese rice cultivars. The results indicated that the Cd accumulation in the brown rice was mainly dependent on the root or shoot Cd concentration. Among the cultivars with nearly equal shoot Cd concentrations, Cd accumulation in brown rice was mainly dependent on the transport of Cd in the shoot. However, the Cd transport in the shoot was significantly restricted by the nodes, especially by the first node. Furthermore, the area of the diffuse vascular bundle in the junctional region of the flag leaf and the first node was a key contributor to the variations in Cd restriction by the nodes.

Characteristics of Au Migration and Concentration Distributions in Au-Doped HgCdTe LPE Materials

NASA Astrophysics Data System (ADS)

Sun, Quanzhi; Yang, Jianrong; Wei, Yanfeng; Zhang, Juan; Sun, Ruiyun

2015-08-01

Annealing techniques and secondary ion mass spectrometry have been used to study the characteristics of Au migration and concentration distributions in HgCdTe materials grown by liquid phase epitaxy. Secondary ion mass spectrometry measurements showed that Au concentrations had obvious positive correlations with Hg-vacancy concentration and dislocation density of the materials. Au atoms migrate toward regions of high Hg-vacancy concentration or move away from these regions when the Hg-vacancy concentration decreases during annealing. The phenomenon can be explained by defect chemical equilibrium theory if Au atoms have a very large migration velocity compared with Hg vacancies. Au atoms will also migrate toward regions of high dislocation density, leading to a peak concentration in the inter-diffusion region of HgCdTe materials near the substrate. By use of an Hg and Te-rich annealing technique, different concentration distributions of both Au atoms and Hg vacancies in HgCdTe materials were obtained, indicating that Au-doped HgCdTe materials can be designed and prepared to satisfy the requirements of HgCdTe devices.

Characterization and environmental risk assessment of heavy metals in construction and demolition wastes from five sources (chemical, metallurgical and light industries, and residential and recycled aggregates).

PubMed

Gao, Xiaofeng; Gu, Yilu; Xie, Tian; Zhen, Guangyin; Huang, Sheng; Zhao, Youcai

2015-06-01

Total concentrations of heavy metals (Cu, Zn, Pb, Cr, Cd, and Ni) were measured among 63 samples of construction and demolition (C&D) wastes collected from chemical, metallurgical and light industries, and residential and recycled aggregates within China for risk assessment. The heavy metal contamination was primarily concentrated in the chemical and metallurgical industries, especially in the electroplating factory and zinc smelting plant. High concentrations of Cd were found in light industry samples, while the residential and recycled aggregate samples were severely polluted by Zn. Six most polluted samples were selected for deep research. Mineralogical analysis by X-ray fluorescence (XRF) spectrometry and X-ray diffraction (XRD), combined with element speciation through European Community Bureau of Reference (BCR) sequential extraction, revealed that a relatively slight corrosion happened in the four samples from electroplating plants but high transfer ability for large quantities of Zn and Cu. Lead arsenate existed in the acid extractable fraction in CI7-8 and potassium chromium oxide existed in the mobility fraction. High concentration of Cr could be in amorphous forms existing in CI9. The high content of sodium in the two samples from zinc smelter plants suggested severe deposition and erosion on the workshop floor. Large quantities of Cu existed as copper halide and most of the Zn appeared to be zinc, zinc oxide, barium zinc oxide, and zincite. From the results of the risk assessment code (RAC), the samples from the electroplating factory posed a very high risk of Zn, Cu, and Cr, a high risk of Ni, a middle risk of Pb, and a low risk of Cd. The samples from the zinc smelting plant presented a high risk of Zn, a middle risk of Cu, and a low risk of Pb, Cr, Cd, and Ni.

Cadmium and mercury exposure over time in Swedish children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lundh, T., E-mail: Thomas.Lundh@med.lu.se

Purpose: Knowledge about changes in exposure to toxic metals over time remains very sparse, in particular for children, the most vulnerable group. Here, we assessed whether a reduction in environmental pollution with cadmium (Cd) and mercury (Hg) caused a change in exposure over time. In total, 1257 children (age 4–9) in two towns in Sweden were sampled once in 1986–2013. Blood concentrations of Cd (b-Cd; n=1120) and Hg (b-Hg; n=560) were determined. Results: The median b-Cd was 0.10 (geometric mean 0.10; range 0.010–0.61) μg/L and b-Hg was 0.91 (geometric mean 0.83; range 0.021–8.2) μg/L. Children living close to a smeltermore » had higher b-Cd and b-Hg than those in urban and rural areas. There was no sex difference in b-Cd or b-Hg, and b-Cd and b-Hg showed no significant accumulation by age. b-Cd decreased only slightly (0.7% per year, p<0.001) over the study period. In contrast, b-Hg did show a clear decrease over the study period (3% per year, p<0.001). Conclusions: The exposure to Cd was very low but still might increase the risk of disease later in life. Moreover, b-Cd only showed a minor decrease, indicating that Cd pollution should be further restricted. b-Hg was relatively low and decreasing, probably because of reduced use of dental amalgam and lower Hg intake from fish. The b-Cd and b-Hg levels decreased much less than the levels of lead in the blood as previously found in the same children. - Highlights: • There are few studies of time trends for exposure to toxic metals, except for lead. • 1986–2013 we studied blood levels of cadmium and mercury in 1257 Swedish children. • The median blood concentration of cadmium was 0.10 μg/L, of mercury 0.83 μg/L. • Cadmium perhaps decreased by 0.7% per year, mercury by 3% per year. • Cadmium accumulation may result in toxic levels in elderly women.« less

Effect of long-term application of biosolids for land reclamation on surface water chemistry.

PubMed

Tian, G; Granato, T C; Pietz, R I; Carlson, C R; Abedin, Z

2006-01-01

Biosolids are known to have a potential to restore degraded land, but the long-term impacts of this practice on the environment, including water quality, still need to be evaluated. The surface water chemistry (NO3-, NH4+, and total P, Cd, Cu, and Hg) was monitored for 31 yr from 1972 to 2002 in a 6000-ha watershed at Fulton County, Illinois, where the Metropolitan Water Reclamation District of Greater Chicago was restoring the productivity of strip-mined land using biosolids. The mean cumulative loading rates during the past 31 yr were 875 dry Mg ha(-1) for 1120-ha fields in the biosolids-amended watershed and 4.3 dry Mg ha(-1) for the 670-ha fields in the control watershed. Biosolids were injected into mine spoil fields as liquid fertilizer from 1972 to 1985, and incorporated as dewatered cake from 1980 to 1996 and air-dried solids from 1987 to 2002. The mean annual loadings of nutrients and trace elements from biosolids in 1 ha were 735 kg N, 530 kg P, 4.5 kg Cd, 30.7 kg Cu, and 0.11 kg Hg in the fields of the biosolids-amended watershed, and negligible in the fields of the control watershed. Sampling of surface water was conducted monthly in the 1970s, and three times per year in the 1980s and 1990s. The water samples were collected from 12 reservoirs and 2 creeks receiving drainage from the fields in the control watershed, and 8 reservoirs and 4 creeks associated with the fields in the biosolids-amended watershed for the analysis of NO3- -N (including NO2- N), NH4+-N, and total P, Cd, Cu, and Hg. Compared to the control (0.18 mg L(-1)), surface water NO3- -N in the biosolids-amended watershed (2.23 mg L(-1)) was consistently higher; however, it was still below the Illinois limit of 10 mg L(-1) for public and food-processing water supplies. Biosolids applications had a significant effect on mean concentrations of ammonium N (0.11 mg L(-1) for control and 0.24 mg L(-1) for biosolids) and total P (0.10 mg L(-1) for control and 0.16 mg L(-1) for biosolids) in surface water. Application of biosolids did not increase the concentrations of Cd and Hg in surface water. The elevation of Cu in surface water with biosolids application only occurred in some years of the first decade, when land-applied sludges contained high concentrations of trace metals, including Cu. In fact, following the promulgation of 40 CFR Part 503, the concentrations of all three metals fell below the method detection level (MDL) in surface water for nearly all samplings. Nitrate in the surface water tends to be higher in spring, and ammonium, total P, and total Hg in summer and fall. Mean nitrate, ammonium, and total phosphorus concentrations were found to be greater in creeks than reservoirs. The results indicate that application of biosolids for land reclamation at high loading rates from 1972 to 2002, with adequate runoff and soil erosion control, had only a minor impact on surface water quality.

Wild flora of mine tailings: perspectives for use in phytoremediation of potentially toxic elements in a semi-arid region in Mexico.

PubMed

Sánchez-López, Ariadna S; Del Carmen A González-Chávez, Ma; Carrillo-González, Rogelio; Vangronsveld, Jaco; Díaz-Garduño, Margarita

2015-01-01

The aim of this research was to identify wild plant species applicable for remediation of mine tailings in arid soils. Plants growing on two mine tailings were identified and evaluated for their potential use in phytoremediation based on the concentration of potentially toxic elements (PTEs) in roots and shoots, bioconcentration (BCF) and translocation factors (TF). Total, water-soluble and DTPA-extractable concentrations of Pb, Cd, Zn, Cu, Co and Ni in rhizospheric and bulk soil were determined. Twelve species can grow on mine tailings, accumulate PTEs concentrations above the commonly accepted phytotoxicity levels, and are suitable for establishing a vegetation cover on barren mine tailings in the Zimapan region. Pteridium sp. is suitable for Zn and Cd phytostabilization. Aster gymnocephalus is a potential phytoextractor for Zn, Cd, Pb and Cu; Gnaphalium sp. for Cu and Crotalaria pumila for Zn. The species play different roles according to the specific conditions where they are growing at one site behaving as a PTEs accumulator and at another as a stabilizer. For this reason and due to the lack of a unified approach for calculation and interpretation of bioaccumulation factors, only considering BCF and TF may be not practical in all cases.

Bioavailability of heavy metals, germanium and rare earth elements at Davidschacht dump-field in mine affected area of Freiberg (Saxony)

NASA Astrophysics Data System (ADS)

Midula, Pavol; Wiche, Oliver

2016-04-01

Bioavailability research presents an essential tool, in modern phytoremediation and phytomining technologies, allowing the estimation of plant available fractions of elements in soils. However, up to date, sufficient interdisciplinary knowledge on the biogeochemically impacted behavior of specific target elements, in particular Ge and REEs in mining affected soils and their uptake into strategically used plants is lacking. This presented work is focused on a correlation study between the concentrations of selected heavy metals, Ge and REEs in soils formed on the top of the dump-field of Davidschacht and the corresponding their concentrations in 12 vascular plant species. The mine-dump of Davidschacht, situated in the Freiberg (Saxony, Germany) municipality area was chosen as the study area, which has been considered to be a high contaminated enclave, due to the mining history of the region. In total 12 sampling sites with differing composition of plant species were selected. At each sampling site soil samples from a soil depth of 0 - 10 cm and samples of plant material (shoots) were taken. The soil samples were analysed for total concentration of elements, pH (H2O) and consequently analysed by 4-step sequential extraction (SE) to determine fractions of elements that are mobile (fraction 1), acid soluble (pH 5) (fraction 2), bound to organic and oxidizable matter (fraction 3) and bound to amorphic oxides (fraction 4). The plant material was decomposed by hydrofluoric acid in order to extract the elements. Concentrations of elements in soil extracts and digestion solutions were analysed by ICP-MS. For all species bioconcentration factor (BCF) was calculated of the total concentration of elements in order to investigate the bioaccumulation potential. Arsenic (As), cadmium (Cd) and lead (Pb) were chosen as the representative heavy metals. Within the REEs neodymium (Nd) and cerium (Ce) were selected as representatives for all REEs, since Nd and Ce correlated significant with the other elements from this group. High amounts of As, Cd, Pb in mould horizons were proved. The surprisingly highest concentrations were determined for As (in average 3328 mg kg-1). The results of the pH measurement indicates acid conditions (in average 4.86, min. 3.89) for whole mine heap. Due to the mobility of Cd and Pb in acid environment, a high mobility of Cd in mobile soil fractions (in average 0.58 mg kg-1) was found, that seems to be responsible for the Cd pollution of Freiberger Mulde river, situated near the dump-field in the East direction from the studied area. The Pb content was in the average 1513 mg kg-1. SE analyses shows, that only the minor amounts of these metals were accounted in fractions I - IV (As: 7.75 %, Pb: 5.48 %, Cd: 26.77 %). The total Ge content in soil samples was 2.7 mg.kg-1in average. The concentrations of Nd and Ce were 17.7 mg kg-1and 38.5 mg kg-1, which is even lower than the average Nd and Ce contents in the Earth crust. However, the concentration of Ge was roughly a factor of two higher, than this average showing a large pool of Ge that could be accessed by phytoextraction. The SE analyses shows, that the average in fractions I - IV is even much lower, than in the case of the above mentioned heavy metals in comparison with Ge (1.75 %), Nd (3.28 %) and Ce (3.12 %). The BCF calculated for plants shows, that the only element, which could be possibly used as the object of phytoaccumulation is Cd (the BCF > 1) in species Populus tremula (3.0, 1.7), Spirea douglasii (1.4, 2.2) and Tanacetum vulgare (3.2, 1.3) at the most sampling places. Since these species represent the natural occurring vegetation of the dump, the use of these species together with soil amendments enhancing the plant availability of elements in soil fractions hold promise for phytoextraction of economically valuable metalloids and consequently an in situ bioremediation of the dump field. This work was realised with the support of Christin Jahns on behalf of the Saxonia company and financial supported by grant scheme VEGA 1/0538/15 . The authors are grateful to students and laboratory assistants contributing in the field work and sample preparation.

Subsurface cadmium loss from a stony soil-effect of cow urine application.

PubMed

Gray, Colin William; Chrystal, Jane Marie; Monaghan, Ross Martin; Cavanagh, Jo-Anne

2017-05-01

Cadmium (Cd) losses in subsurface flow from stony soils that have received cow urine are potentially important, but poorly understood. This study investigated Cd loss from a soil under a winter dairy-grazed forage crop that was grazed either conventionally (24 h) or with restricted grazing (6 h). This provided an opportunity to test the hypothesis that urine inputs could increase Cd concentrations in drainage. It was thought this would be a result of cow urine either (i) enhancing dissolved organic carbon (DOC) concentrations via an increase in soil pH, resulting in the formation of soluble Cd-organic carbon complexes and, or (ii) greater inputs of chloride (Cl) via cow urine, promoting the formation of soluble Cd-Cl complexes. Cadmium concentrations in subsurface flow were generally low, with a spike above the water quality guidelines for a month after the 24-h grazing. Cadmium fluxes were on average 0.30 g Cd ha -1  year -1 (0.27-0.32 g Cd ha -1  year -1 ), in line with previous estimates for agricultural soils. The mean Cd concentration in drainage from the 24-h grazed plots was significantly higher (P < 0.05) than 6-h plots. No increase in DOC concentrations between the treatments was found. However, Cl concentrations in drainage were significantly higher (P < 0.001) from the 24-h than the 6-h grazed treatment plots, and positively correlated with Cd concentrations, and therefore, a possible mechanism increasing Cd mobility in soil. Further study is warranted to confirm the mechanisms involved and quantities of Cd lost from other systems.

Distance-dependent varieties of microbial community structure and metabolic functions in the rhizosphere of Sedum alfredii Hance during phytoextraction of a cadmium-contaminated soil.

PubMed

Yang, Wenhao; Zhang, Taoxiang; Lin, Sen; Ni, Wuzhong

2017-06-01

The recovery of microbial community and activities is crucial to the remediation of contaminated soils. Distance-dependent variations of microbial community composition and metabolic characteristics in the rhizospheric soil of hyperaccumulator during phytoextraction are poorly understood. A 12-month phytoextraction experiment with Sedum alfredii in a Cd-contaminated soil was conducted. A pre-stratified rhizobox was used for separating sub-layer rhizospheric (0-2, 2-4, 4-6, 6-8, 8-10 mm from the root mat)/bulk soils. Soil microbial structure and function were analyzed by phospholipid fatty acid (PLFA) and MicroResp™ methods. The concentrations of total and specified PLFA biomarkers and the utilization rates for the 14 substrates (organic carbon) in the 0-2-mm sub-layer rhizospheric soil were significantly increased, as well as decreased with the increase in the distance from the root mat. Microbial structure measured by the ratios of different groups of PLFAs such as fungal/bacterial, monounsaturated/saturated, ratios of Gram-positive to Gram-negative (GP/GN) bacterial, and cyclopropyl/monoenoic precursors and 19:0 cyclo/18:1ω7c were significantly changed in the 0-2-mm soil. The PLFA contents and substrate utilization rates were negatively correlated with pH and total, acid-soluble, and reducible fractions of Cd, while positively correlated with labile carbon. The dynamics of microbial community were likely due to root exudates and Cd uptake by S. alfredii. This study revealed the stimulations and gradient changes of rhizosphere microbial community through phytoextraction, as reduced Cd concentration, pH, and increased labile carbons are due to the microbial community responses.

Heavy metal pollution and ecological risk assessment of the paddy soils near a zinc-lead mining area in Hunan.

PubMed

Lu, Sijin; Wang, Yeyao; Teng, Yanguo; Yu, Xuan

2015-10-01

Soil pollution by Cd, Hg, As, Pb, Cr, Cu, and Zn was characterized in the area of the mining and smelting of metal ores at Guiyang, northeast of Hunan Province. A total of 150 topsoil (0-20 cm) samples were collected in May 2012 with a nominal density of one sample per 4 km(2). High concentrations of heavy metals especially, Cd, Zn, and Pb were found in many of the samples taken from surrounding paddy soil, indicating a certain extent of spreading of heavy metal pollution. Sequential extraction technique and risk assessment code (RAC) were used to study the mobility of chemical forms of heavy metals in the soils and their ecological risk. The results reveal that Cd represents a high ecological risk due to its highest percentage of the exchangeable and carbonate fractions. The metals of Zn and Cu pose a medium risk, and the rest of the metals represent a low environmental risk. The range of the potential ecological risk of soil calculated by risk index (RI) was 123.5~2791.2 and revealed a considerable-high ecological risk in study area especially in the neighboring and surrounding the mining activities area. Additionally, cluster analyses suggested that metals such as Pb, As, Hg, Zn, and Cd could be from the same sources probably related to the acidic drainage and wind transport of dust. Cluster analysis also clearly distinguishes the samples with similar characteristics according to their spatial distribution. The results could be used during the ecological risk screening stage, in conjunction with total concentrations and metal fractionation values to better estimate ecological risk.

Fractionation of trace elements in agricultural soils using ultrasound assisted sequential extraction prior to inductively coupled plasma mass spectrometric determination.

PubMed

Matong, Joseph M; Nyaba, Luthando; Nomngongo, Philiswa N

2016-07-01

The main objectives of this study were to determine the concentration of fourteen trace elements and to investigate their distribution as well as a contamination levels in selected agricultural soils. An ultrasonic assisted sequential extraction procedure derived from three-step BCR method was used for fractionation of trace elements. The total concentration of trace elements in soil samples was obtained by total digestion method in soil samples with aqua regia. The results of the extractable fractions revealed that most of the target trace elements can be transferred to the human being through the food chain, thus leading to serious human health. Enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), risk assessment code (RAC) and individual contamination factors (ICF) were used to assess the environmental impacts of trace metals in soil samples. The EF revealed that Cd was enriched by 3.1-7.2 (except in Soil 1). The Igeo results showed that the soils in the study area was moderately contaminated with Fe, and heavily to extremely polluted with Cd. The soil samples from the unplanted field was found to have highest contamination factor for Cd and lowest for Pb. Soil 3 showed a high risk for Tl and Cd with RAC values of greater than or equal to 50%. In addition, Fe, Ni, Cu, V, As, Mo (except Soil 2), Sb and Pb posed low environmental risk. The modified BCR sequential extraction method provided more information about mobility and environmental implication of studied trace elements in the study area. Copyright © 2016 Elsevier Ltd. All rights reserved.

Total arsenic, lead, and cadmium levels in vegetables cultivated at the Andean villages of northern Chile.

PubMed

Queirolo, F; Stegen, S; Restovic, M; Paz, M; Ostapczuk, P; Schwuger, M J; Muñoz, L

2000-06-08

Various vegetables (broad beans, corn, potato, alfalfa and onion) were sampled in northern Chile, Antofagasta Region. They are the basis of human nutrition in this region and of great relevance to human health. This region is characterized by volcanic events (eruptions, thermal springs, etc.). Most of the vegetables cultivated in this area enter the local markets for a population of approximately 4000 people, whose ancestors were mainly atacameños and quechuas (local indigenous people). The cadmium and lead in these foods was determined by differential pulse anodic stripping voltammetry (DPASV). Results indicate that the highest concentration of Pb and Cd are in the potato skin, while the edible part of the potatoes contained a lower concentration of these metals. The INAA analyses of As in the vegetables from Socaire and Talabre, two towns located close to active volcanoes (e.g. Lascar), show a very high As content: 1850 microg/kg in corn (Socaire) and 860 microg/kg in potatoes (+ skin) (Talabre). These values exceed the National Standard for arsenic (500 microg/kg) by approximately 400% and 180%, respectively. In general, the data show a concentration of Pb greater than Cd with the potential for some vegetables to accumulate heavy metals, The values, expressed in fresh weight, vary from 0.2 to 40 microg/g for Cd and from 0.6 to 94 microg/g for Pb. These concentration intervals, except that of arsenic, are within the recommended standards in the Food Sanitary Regulation (Decree 977), which, expressed as fresh weight, must be equal to or smaller than 500 microg/kg for Pb. There is no legal standard for Cd.

Nondestructive pollution exposure assessment in the European hedgehog (Erinaceus europaeus): I. Relationships between concentrations of metals and arsenic in hair, spines, and soil.

PubMed

D'Havé, Helga; Scheirs, Jan; Mubiana, Valentine Kayawe; Verhagen, Ron; Blust, Ronny; De Coen, Wim

2005-09-01

Conventional metal exposure assessment in terrestrial mammals is generally based on organ analyses of sacrificed animals. Few studies on mammals use nondestructive methodologies despite the growing ethical concern over the use of destructive sampling. Nondestructive methods involve minimal stress to populations and permit successive biomonitoring of the same populations and individuals. In the present study we assessed metal exposure of hedgehogs (Erinaceus europaeus) by investigating relationships between concentrations of metals (Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) and As in soil samples and in hair and spines of hedgehogs. Samples were collected in seven study sites along a metal pollution gradient, characterized by decreasing total soil Ag, As, Cd, Cu, Ni, and Pb concentrations with increasing distance from a nonferrous metallurgic factory. For a number of elements, soil contamination was related both to distance to the smelter and to habitat. Soil concentrations were positively related to levels in hair and spines for Ag, As, Cd, and Pb and thus to hedgehog exposure. Metal concentrations in soil did not relate to metal concentrations in hair and spines for essential elements (e.g., Cu, Fe, Mn, Ni, and Zn), except Co in hair and soil. Our results demonstrate that, at least for nonessential elements, concentrations in soils can be used to predict contamination of these elements in hedgehogs or vice versa. Furthermore, hedgehog exposure increased toward the smelter and was higher for hedgehogs foraging in grasslands than for animals foraging in the forest. Moreover, we believe that hair and spines are promising tools in terrestrial wildlife exposure assessment studies of metals and As.

Blood cadmium concentrations and environmental exposure sources in newcomer South and East Asian women in the Greater Toronto Area, Canada.

PubMed

Wiseman, C L S; Parnia, A; Chakravartty, D; Archbold, J; Zawar, N; Copes, R; Cole, D C

2017-04-01

Immigrant women are often identified as being particularly vulnerable to environmental exposures and health effects. The availability of biomonitoring data on newcomers is limited, thus, presenting a challenge to public health practitioners in the identification of priorities for intervention. In fulfillment of data needs, the purpose of this study was to characterize blood concentrations of cadmium (Cd) among newcomer women of reproductive age (19-45 years of age) living in the Greater Toronto Area (GTA), Canada and to assess potential sources of environmental exposures. A community-based model, engaging peer researchers from the communities of interest, was used for recruitment and follow-up purposes. Blood samples were taken from a total of 211 newcomer women from South and East Asia, representing primary, regional origins of immigrants to the GTA, and environmental exposure sources were assessed via telephone survey. Metal concentrations were measured in blood samples (diluted with 0.5% (v/v) ammonium hydroxide and 0.1% (v/v) octylphenol ethoxylate) using a quadrupole ICP-MS. Survey questions addressed a wide range of environmental exposure sources, including dietary and smoking patterns and use of nutritional supplements, herbal products and cosmetics. A geometric mean (GM) blood Cd concentration of 0.39µg/L (SD:±2.07µg/L) was determined for study participants (min/max: <0.045µg/L (LOD)/2.36µg/L). Several variables including low educational attainment (Relative Ratio (RR) (adjusted)=1.50; 95% CI 1.17-1.91), milk consumption (RR (adjusted)=0.86; 95% CI 0.76-0.97), and use of zinc supplements (RR (adjusted)=0.76; 95% CI 0.64-0.95) were observed to be significantly associated with blood Cd concentrations in the adjusted regression model. The variable domains socioeconomic status (R 2 adj =0.11) and country of origin (R 2 adj =0.236) were the strongest predictors of blood Cd. Blood Cd concentrations fell below those generally considered to be of human health concern. However, negative health effects cannot be entirely excluded, especially for those that fall in the upper percentile range of the distribution, given the mounting evidence for negative health outcomes at low environmental exposure concentrations. Copyright © 2016 Elsevier Inc. All rights reserved.

Human milk oligosaccharide concentration and risk of postnatal transmission of HIV through breastfeeding123

PubMed Central

Kuhn, Louise; Kim, Hae-Young; Hsiao, Lauren; Nissan, Caroline; Sinkala, Moses; Kankasa, Chipepo; Mwiya, Mwiya; Thea, Donald M; Aldrovandi, Grace M

2012-01-01

Background: The inefficiency of HIV breast-milk transmission may be caused by the presence of immunologically active factors, including human milk oligosaccharides (HMOs). Objective: We investigated whether HMO concentrations are associated with a reduced risk of postnatal HIV transmission. Design: A nested case-control study was conducted within a larger cohort study of HIV-infected women and their infants followed from birth to 24 mo in Lusaka, Zambia. Breast-milk samples collected at 1 mo from 81 HIV-infected women who transmitted via breastfeeding, a random sample of 86 HIV-infected women who did not transmit despite breastfeeding, and 36 uninfected breastfeeding women were selected. Total and specific HMO concentrations were measured by HPLC and compared between groups with adjustment for confounders by using logistic regression. Results: HIV-infected women with total HMOs above the median (1.87 g/L) were less likely to transmit via breastfeeding (OR: 0.45; 95% CI: 0.21, 0.97; P = 0.04) after adjustment for CD4 count and breast-milk HIV RNA concentrations; a trend toward higher concentrations of lacto-N-neotetraose being associated with reduced transmission (OR: 0.49; 95% CI: 0.23, 1.04; P = 0.06) was also observed. The proportion of 3′-sialyllactose (3′-SL) per total HMOs was higher among transmitting than among nontransmitting women (P = 0.003) and correlated with higher plasma and breast-milk HIV RNA and lower CD4 counts. Neither Secretor nor Lewis status distinguished between transmitting and nontransmitting women. Conclusions: Higher concentrations of non-3′-SL HMOs were associated with protection against postnatal HIV transmission independent of other known risk factors. Further study of these novel, potentially anti-HIV components of breast milk is warranted. This trial was registered at clinicaltrials.gov as NCT00310726. PMID:22894939

Cadmium removal from wastewater by sponge iron sphere prepared by charcoal direct reduction.

PubMed

Li, Junguo; Li, Jun; Li, Yungang

2009-01-01

Sponge iron sphere (SIS), made of concentrated iron powder and possessed high activity and intension, was prepared through the process of palletizing, roasting and direct reduction by charcoal. The sponge iron sphere could remove most of Cd(2+) from wastewater. The results showed the Cd(2+) removal followed the first order reaction. Initial pH value played an important role in Cd(2+) removal. With original initial pH, Cd(2+) removal decreased to the minimum and then increased slightly with the rising of original concentration. The removal rate constant was -0.1263 and -0.0711 h(-1), respectively, under the Cd(2+) concentration of 50 and 200 mg/L. When the initial pH was adjusted to 3.0, the removal rate constant could increase to -9.896 and -4.351 h(-1), respectively. The removal percentage almost reached to 100% when Cd(2+) concentration was below 100 mg/L. While Cd(2+) concentration was above 100 mg/L, Cd(2+) removal percentage decreased slightly. In dynamic experiments, the column filled with sponge iron sphere exhibited favorable permeability. There was no sphere pulverization and conglutination between spheres. In contrast to the static state experiments, the Cd(2+) removal percentage in dynamic state experiment was lower, and the removal Cd(2+) quantity was 1.749 mg/g.

Effectiveness Study of Drinking Water Treatment Using Clays/Andisol Adsorbent in Lariat Heavy Metal Cadmium (Cd) and Bacterial Pathogens

NASA Astrophysics Data System (ADS)

Pranoto; Inayati; Firmansyah, Fathoni

2018-04-01

Water is a natural resource that is essential for all living creatures. In addition, water also caused of disease affecting humans. The existence of one of heavy metal pollutants cadmium (Cd) in the body of water is an environmental problem having a negative impact on the quality of water resources. Adsorption is one of the ways or methods that are often used for the treatment of wastewater. Clay and allophanic soil were used as Cd adsorbent by batch method. Ceramic filter was used to reduce Cd concentration in the ground water. This study aims to determine the effect of the composition of clay and Allophane, activation temperature and contact time on the adsorption capacity of Cd in the model solution. The optimum adsorption condition and the effectiveness of drinking water treatment in accordance with Regulation of the Minister of Health using clay/Andisol adsorbents in ensnare heavy metals Cd and bacterial pathogens. Identification and characterization of adsorbent is done by using NaF, Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), specific surface area and total acidity specific. The Cd metal concentrations were analysed by atomic absorption spectroscopy. Adsorption isotherms determined by Freundlich and Langmuir equations. Modified water purification technology using ceramic filters are made with a mixture of clay and Andisol composition. The results showed samples of clay and Andisol containing minerals. The optimum condition of adsorption was achieved at 200 °C of activation temperature, 60 minutes of contact time and the 60:40 of clay:Andisol adsorbent composition. Freundlich isotherm represented Cd adsorption on the clay/Andisol adsorbent with a coefficient of determination (R2=0.99) and constant (k=1.59), higher than Langmuir (R2=0.89). The measurement results show the water purification technology using ceramic filters effectively reduce E. coli bacterial and Cd content in the water.

Role of metal mixtures (Ca, Cu and Pb) on Cd bioaccumulation and phytochelatin production by Chlamydomonas reinhardtii.

PubMed

Abboud, Pauline; Wilkinson, Kevin J

2013-08-01

The goal of the study was to determine whether metal uptake and biological effects could be predicted by free ion concentrations when organisms were exposed to Cd and a second metal. Bioaccumulation and algal phytochelatin (PC) concentrations were determined for Chlamydomonas reinhardtii following a 6-h exposure. Bioaccumulation results, after six hours of exposure, showed that Cd uptake decreased in the presence of relatively high concentrations of Ca, Cu and Pb, however, Cd bioaccumulation increased in the presence of ca. equimolar concentrations of Cu. A good correlation was observed between the production of PCs and the amount of metals bioaccumulated for the binary mixtures of Cd-Pb and Cd-Cu, but not the Cd-Ca mixture. Overall, the results suggested that, in the case of mixtures, bioaccumulated metal rather than free ion concentrations would be a better predictor of biological effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Different strategies of cadmium detoxification in the submerged macrophyte Ceratophyllum demersum L.

PubMed

Andresen, Elisa; Mattusch, Jürgen; Wellenreuther, Gerd; Thomas, George; Arroyo Abad, Uriel; Küpper, Hendrik

2013-10-01

The heavy metal cadmium (Cd) is highly toxic to plants. To understand the mechanisms of tolerance and resistance to Cd, we treated the rootless, submerged macrophyte Ceratophyllum demersum L. with sub-micromolar concentrations of Cd under environmentally relevant conditions. X-ray fluorescence measurements revealed changing distribution patterns of Cd and Zn at non-toxic (0.2 nM, 2 nM), moderately toxic (20 nM) and highly toxic (200 nM) levels of Cd. Increasing Cd concentrations led to enhanced sequestration of Cd into non-photosynthetic tissues like epidermis and vein. At toxic Cd concentrations, Zn was redistributed and mainly found in the vein. Cd treatment induced the synthesis of phytochelatins (PCs) in the plants, with a threshold of induction already at 20 nM Cd for PC3. In comparison, in plants treated with Cu, elevated PC levels were detected only at the highest concentrations (100-200 nM Cu). Our results show that also non-accumulators like C. demersum store toxic metals in tissues where the heavy metal interferes least with metabolic pathways, but remaining toxicity interferes with micronutrient distribution. Furthermore, we found that the induction of phytochelatins is not proportional to metal concentration, but has a distinct threshold, specific for each PC species. Finally we could show that 20 nM Cd, which was previously regarded as non-toxic to most plants, already induces detoxifying mechanisms.

Iodine Doping of CdTe and CdMgTe for Photovoltaic Applications

DOE PAGES

Ogedengbe, O. S.; Swartz, C. H.; Jayathilaka, P. A. R. D.; ...

2017-06-06

Here, iodine-doped CdTe and Cd 1-xMg xTe layers were grown by molecular beam epitaxy. Secondary ion mass spectrometry characterization was used to measure dopant concentration, while Hall measurement was used for determining carrier concentration. Photoluminescence intensity and time-resolved photoluminescence techniques were used for optical characterization. Maximum n-type carrier concentrations of 7.4 x 10 18 cm -3 for CdTe and 3 x 10 17 cm -3 for Cd 0.65Mg 0.35Te were achieved. Studies suggest that electrically active doping with iodine is limited with dopant concentration much above these values. Dopant activation of about 80% was observed in most of the CdTemore » samples. The estimated activation energy is about 6 meV for CdTe and the value for Cd 0.65Mg 0.35Te is about 58 meV. Iodine-doped samples exhibit long lifetimes with no evidence of photoluminescence degradation with doping as high as 2 x 10 18 cm -3, while indium shows substantial non-radiative recombination at carrier concentrations above 5 x 10 16 cm -3. Iodine was shown to be thermally stable in CdTe at temperatures up to 600 °C. Results suggest iodine may be a preferred n-type dopant compared to indium in achieving heavily doped n-type CdTe.« less

Defect chemistry and characterization of (Hg, Cd)Te

NASA Technical Reports Server (NTRS)

Vydyanath, H. R.

1981-01-01

Single crystal samples of phosphorus doped Hg sub 0.8 Cd sub 0.2 Te were anneald at temperatures varying from 450 C to 600 C in various Hg atmospheres. The samples were quenched to room temperature from the annealing temperatures. Hall effect and mobility measurements were performed at 77 K on all these samples. The results indicate the crystals to be p type for a total phosphorus concentration of 10 to the 19th power/cu cm in all the samples. The hole concentration at 77 K increases with increasing Hg pressures at 450 C and 500 C contrary to the observation in undoped crystals. Also, at low Hg pressures the concentration of holes in the phosphorus doped crystals is lower than in the undoped crystals. The hole concentration in all the samples is lower than the intrinsic carrier concentration at the annealing temperatures. The hole mobility in the doped crystals is similar to that in the undoped crystals. A defect model according to which phosphorus behaves as a single acceptor interstitially, occupying Te lattice sites while it acts as a single donor occupying Hg lattice sites was established. Equilibrum constants established for the incorporation of all the phosphorus species explain the experimental results

Systematic Evaluation of the Efficacy of Chlorine Dioxide in Decontamination of Building Interior Surfaces Contaminated with Anthrax Spores▿

PubMed Central

Rastogi, Vipin K.; Ryan, Shawn P.; Wallace, Lalena; Smith, Lisa S.; Shah, Saumil S.; Martin, G. Blair

2010-01-01

Efficacy of chlorine dioxide (CD) gas generated by two distinct generation systems, Sabre (wet system with gas generated in water) and ClorDiSys (dry system with gas generated in air), was evaluated for inactivation of Bacillus anthracis spores on six building interior surfaces. The six building materials included carpet, acoustic ceiling tile, unpainted cinder block, painted I-beam steel, painted wallboard, and unpainted pinewood. There was no statistically significant difference in the data due to the CD generation technology at a 95% confidence level. Note that a common method of CD gas measurement was used for both wet and dry CD generation types. Doses generated by combinations of different concentrations of CD gas (500, 1,000, 1,500, or 3,000 parts per million of volume [ppmv]) and exposure times (ranging between 0.5 and 12 h) were used to evaluate the relative role of fumigant exposure period and total dose in the decontamination of building surfaces. The results showed that the time required to achieve at least a 6-log reduction in viable spores is clearly a function of the material type on which the spores are inoculated. The wood and cinder block coupons required a longer exposure time to achieve a 6-log reduction. The only material showing a clear statistical difference in rate of decay of viable spores as a function of concentration was cinder block. For all other materials, the profile of spore kill (i.e., change in number of viable spores with exposure time) was not dependent upon fumigant concentration (500 to 3,000 ppmv). The CD dose required for complete spore kill on biological indicators (typically, 1E6 spores of Bacillus atrophaeus on stainless steel) was significantly less than that required for decontamination of most of the building materials tested. PMID:20305025

PM2.5, PM10 and health risk assessment of heavy metals in a typical printed circuit noards manufacturing workshop.

PubMed

Zhou, Peng; Guo, Jie; Zhou, Xiaoyu; Zhang, Wei; Liu, Lili; Liu, Yangcheng; Lin, Kuangfei

2014-10-01

A typical Printed Circuit Board (PCB) manufacturer was chosen as the object of this study. During PCB processing, fine particulate matter and heavy metals (Cu, Zn, Pb, Cr, Cd and Ni) will be released into the air and dust, which then impact workers' health and the environment. The concentrations of total suspended particle (TSP), PM10 and PM2.5 in the off-site were 106.3, 90.0 and 50.2μg/m(3), respectively, while the concentrations of TSP, PM10 and PM2.5 in the workshops ranged from 36.1 to 365.3, from 27.1 to 289.8 and from 22.1 to 212.3μg/m(3), respectively. Almost all six of the heavy metals were detected in all of the particle samples except Cd. For each workshop, it was obvious that Zn was the most enriched metal in TSP, followed by Cu>Pb (Cr)>Ni>Cd, and the same trend was found for PM10 and PM2.5. In the dust samples, Cu (which ranged from 4.02 to 56.31mg/g) was the most enriched metal, followed by Zn, Cr, Pb, Ni and Cd, and the corresponding concentrations ranged from 0.77 to 4.47, 0.37 to 1.59, 0.26 to 0.84, 0.13 to 0.44 and nd to 0.078mg/g, respectively. The health risk assessment showed that noncancerous effects are unlikely for Zn, Pb, Cr, Cu, Cd and Ni. The carcinogenic risks for Cd and Ni were all lower than 10(-6), except for Cr. This result indicates that carcinogenic risks for workers are relatively possible in the workshops. These findings suggest that this technology is advanced from the perspective of environmental protection in the waste PCB's recycling industry. Copyright © 2014. Published by Elsevier B.V.

Cadmium body burden and increased blood pressure in middle-aged American Indians: the Strong Heart Study

PubMed Central

Franceschini, Nora; Fry, Rebecca; Balakrishnan, Poojitha; Navas-Acien, Ana; Oliver-Williams, Clare; Howard, Annie G; Cole, Shelley A; Haack, Karin; Lange, Ethan M.; Howard, Barbara V.; Best, Lyle G; Francesconi, Kevin A.; Goessler, Walter; Umans, Jason G; Tellez-Plaza, Maria

2016-01-01

Cadmium is an environmental pollutant that has been associated with cardiovascular disease in populations, but the relationship of cadmium with hypertension has been inconsistent. We studied the association between urinary cadmium concentrations, a measure of total body burden, and blood pressure in American Indians, a U.S. population with above national average cadmium burden. Urinary cadmium (Cd) was measured using inductively coupled plasma mass spectrometry, and adjusted for urinary creatinine concentration. Among 3,714 middle-aged American Indian participants of the Strong Heart Study (mean age 56 years, 41% male, 67% ever-smokers, 23% taking anti-hypertensive medications), urinary Cd ranged from 0.01 to 78.48 μg/g creatinine (geometric mean=0.94 μg/g) and it was correlated with smoking pack-year among ever-smokers (r2=0.16, P<0.0001). Participants who were smokers were on average light smokers (mean 10.8 pack-years), and urinary Cd was similarly elevated in light- and never-smokers (geometric means of 0.88 μg/g creatinine for both categories). Log-transformed urinary Cd was significantly associated with higher systolic blood pressure in models adjusted for age, sex, geographic area, body mass index, smoking (ever vs. never, and cumulative pack-years) and kidney function (mean blood pressure difference by lnCd concentration [β]=1.64, P=0.002). These associations were present among light- and never-smokers (β=2.03, P=0.002, n=2,627), although not significant among never-smokers (β=1.22, P=0.18, n=1,260). Cd was also associated with diastolic blood pressure among light- and never-smokers (β=0.94, P=0.004). These findings suggest there is a relationship between cadmium body burden and increased blood pressure in American Indians, a population with increased cardiovascular disease risk. PMID:27629244

Systematic evaluation of the efficacy of chlorine dioxide in decontamination of building interior surfaces contaminated with anthrax spores.

PubMed

Rastogi, Vipin K; Ryan, Shawn P; Wallace, Lalena; Smith, Lisa S; Shah, Saumil S; Martin, G Blair

2010-05-01

Efficacy of chlorine dioxide (CD) gas generated by two distinct generation systems, Sabre (wet system with gas generated in water) and ClorDiSys (dry system with gas generated in air), was evaluated for inactivation of Bacillus anthracis spores on six building interior surfaces. The six building materials included carpet, acoustic ceiling tile, unpainted cinder block, painted I-beam steel, painted wallboard, and unpainted pinewood. There was no statistically significant difference in the data due to the CD generation technology at a 95% confidence level. Note that a common method of CD gas measurement was used for both wet and dry CD generation types. Doses generated by combinations of different concentrations of CD gas (500, 1,000, 1,500, or 3,000 parts per million of volume [ppmv]) and exposure times (ranging between 0.5 and 12 h) were used to evaluate the relative role of fumigant exposure period and total dose in the decontamination of building surfaces. The results showed that the time required to achieve at least a 6-log reduction in viable spores is clearly a function of the material type on which the spores are inoculated. The wood and cinder block coupons required a longer exposure time to achieve a 6-log reduction. The only material showing a clear statistical difference in rate of decay of viable spores as a function of concentration was cinder block. For all other materials, the profile of spore kill (i.e., change in number of viable spores with exposure time) was not dependent upon fumigant concentration (500 to 3,000 ppmv). The CD dose required for complete spore kill on biological indicators (typically, 1E6 spores of Bacillus atrophaeus on stainless steel) was significantly less than that required for decontamination of most of the building materials tested.

Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd-Pb exposures.

PubMed

Xin, Junliang; Huang, Baifei; Yang, Zhongyi; Yuan, Jiangang; Dai, Hongwen; Qiu, Qiu

2010-03-15

A pot experiment was conducted to investigate the stability of Cd and/or Pb accumulation in shoot of Cd and Pb pollution-safe cultivars (PSCs), the hereditary pattern of shoot Cd accumulation, and the transfer potentials of Cd and Pb in water spinach (Ipomoea aquatica Forsk.). A typical Cd-PSC, a typical non-Cd-PSC (Cd accumulative cultivar), a hybrid from the former two cultivars, and two typical Cd+Pb-PSCs were grown in seven soils with different concentrations of Cd and Pb. The results showed that concentrations of Cd and Pb in shoot of the PSCs were always lower than the non-PSC and the highest Cd and Pb transfer factors were also always observed in the non-PSC, indicating the stability of the PSCs in Cd and Pb accumulation. Shoot Cd concentration seemed to be controlled by high Cd dominant gene(s) and thus crossbreeding might not minimize Cd accumulation in water spinach. Interaction between Cd and Pb in soils affected the accumulations of the metals in shoot of water spinach. Under middle Cd and Pb treatments, the presence of higher Pb promoted the accumulation of Cd. However, under high Pb treatment, accumulations of Cd and Pb were both restricted. (c) 2009 Elsevier B.V. All rights reserved.

Heavy metals in navel orange orchards of Xinfeng County and their transfer from soils to navel oranges.

PubMed

Cheng, Jinjin; Ding, Changfeng; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

2015-12-01

This study investigated heavy metal concentrations in soils and navel oranges of Xinfeng County, a well-known navel orange producing area of China. The results showed that the average concentrations of lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As) and mercury (Hg) in orchard soils all increased compared to the regional background values, especially for Cd, which increased by 422%. When compared to the Chinese Environmental Quality Standard for soil (GB15618-1995), Pb, Cr and Hg concentrations in all orchard soil samples were below the limit standards, but Cd concentrations in 24 soil samples (21%) and As concentrations in 8 soil samples (7%) exceeded the limit standards. However, concentrations of all heavy metals in navel orange pulps were within the National Food Safety Standard of China (GB 2762-2012). Dietary risk assessment also showed that the exposure to these five heavy metals by consumption of navel oranges could hardly pose adverse health effects on adults and children. Since the range and degree of soil Cd pollution was widest and the most severe of all, Cd was taken as an example to reveal the transfer characteristics of heavy metals in soil-navel orange system. Cd concentrations in different organs of navel orange trees decreased in the following order: root>leaf>peel>pulp. That navel oranges planted in the Cd contaminated soils were within the national food safety standard was mainly due to the low transfer factor for Cd from soil to pulp (TFpulp). Further studies showed that TFpulp was significantly negatively correlated with soil pH, organic carbon (OC) and cation exchange capacity (CEC). Based on these soil properties, a prediction equation for TFpulp was established, which indicated that the risk for Cd concentration of navel orange pulp exceeding the national food limit is generally low, when soil Cd concentration is below 7.30 mg/kg. If appropriate actions are taken to increase soil pH, OC and CEC, Cd concentrations in navel orange pulps could be further reduced. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of iron plaque on uptake and accumulation of Cd by rice (Oryza sativa L.) seedlings grown in soil.

PubMed

Liu, Houjun; Zhang, Junling; Christie, Peter; Zhang, Fusuo

2008-05-15

Iron plaque is ubiquitously formed on the root surfaces of rice. However, little is known about the role of iron plaque in Cd movement from soil to the plant aboveground parts. A pot experiment was conducted to investigate the influence of iron plaque in Cd uptake and accumulation by rice seedlings in soil. Rice seedlings were pre-cultivated in solution culture for 16 days. Two seedlings were transplanted in a nylon bag containing no substrate but surrounded by soil amended with Fe and Cd combined at rates of 0, 1, or 2 g Fe kg(-1) and 0, 2.0, or 10 mg Cd kg(-1) soil. Fe was added to induce different amounts of iron plaque, and Cd to simulate Cd-polluted soils. Plants were grown for a further 43 days and then harvested. The length of the longest leaf and SPAD values of the newly mature leaves were measured during plant growth. Fe and Cd concentrations were determined in dithionite-citrate-bicarbonate (DCB) soil extracts and in plant roots and shoots. Shoot and root dry weights were significantly affected by Fe supply level but not by added Cd. Root dry weight declined with increasing Fe supply but shoot dry weight decreased at 2 g Fe kg(-1) and increased at 1 g Fe kg(-1) (except at 2 mg Cd kg(-1)). The length of the longest leaf and SPAD values of the newly mature leaves were significantly affected by plant growth stage and added Fe and Cd. Fe tended to diminish the negative effect of Cd on these two parameters. Cd concentrations in DCB extracts increased with increasing Cd and Fe supply. In contrast, external Fe supply markedly reduced shoot and root Cd concentrations and there was generally no significant difference between the two Fe supply levels. Shoot and root Cd concentrations increased with increasing Cd addition. Root Cd concentrations were negatively correlated with root Fe concentrations. The proportion of Cd in DCB extracts was significantly lower than in roots or shoots. The results indicate that enhanced Fe uptake by plants can diminish the negative effects of Cd to some extent and that iron plaque on root surfaces is of little significance in affecting uptake and accumulation of Cd by rice plants.

Finger printing of mixed contaminants from former manufactured gas plant (MGP) site soils: Implications to bioremediation.

PubMed

Thavamani, Palanisami; Megharaj, Mallavarapu; Krishnamurti, G S R; McFarland, Ross; Naidu, Ravi

2011-01-01

Contaminants in general do not occur as single chemicals but as mixtures at any contaminated site. Gasworks sites are the typical mixed contaminated sites. These sites are not only subjected to PAH contamination but also varying degrees of heavy metal contamination. Bioremediation in these sites is often hindered by the presence of heavy metals. The co-occurrence of PAHs with heavy metals has not been systematically investigated. Metals are reported to inhibit the general soil microbiological processes. The total concentration of soluble metal in the system includes both free metal ion and complexed forms. Within bioavailable fraction, the most toxic form is the free metal species, which was not addressed well so far in gas works site characterisation. This study underpins the science and importance of metal bioavailability and speciation based site characterisation in mixed contaminated sites. In this study a detailed elemental chemistry of the gas works site soils are discussed using different methods. The PAH contamination was contributed by both low and high molecular weight PAHs. The total PAHs concentration ranged from 335 to 8645 mg/kg. Among most toxic metals Pb was found in high concentration ranging from 88 to 671 mg/kg, Cd 8 to 112 mg/kg and Zn varied from 64 to 488 mg/kg. Thermodynamic chemical equilibrium model VMINTEQ (Ver 2.52) was used to calculate the free metal species in gas works site soils. The percentage free metal species showed a different trend compared to total metal concentrations, free Zn species ranged 18-86%, free Cd was 26-87% and Pb showed lowest free metal percentage (0-17%). The bioavailable metal species and its implications to bioremediation have also been discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Growth responses of three ornamental plants to Cd and Cd-Pb stress and their metal accumulation characteristics.

PubMed

Liu, Jia-nv; Zhou, Qi-xing; Sun, Ting; Ma, Lena Q; Wang, Song

2008-02-28

Up to now, there was no document on ornamental plants that had been applied to phytoremediation, which can remedy contaminated environment and beautify it at the same time. Thus, the growth responses and possible phytoremediation ability of three ornamental plants selected from the previous preliminary experiments were further examined under single Cd or combined Cd-Pb stress. The results showed that these tested plants had higher tolerance to Cd and Pb contamination and could effectively accumulate the metals, especially for Calendula officinalis and Althaea rosea. For C. officinalis, it grew normally in soils containing 100 mg kg(-1) Cd without suffering phytotoxicity, and the Cd concentration in the roots was up to 1084 mg kg(-1) while the Cd concentration in the shoots was 284 mg kg(-1). For A. rosea, the Cd accumulation in the shoots was higher than that in the roots when the Cd concentration in soils was <100 mg kg(-1), and reached 100 mg kg(-1) as the criteria of a Cd hyperaccumulator when the Cd concentration in soils was 100 mg kg(-1). Their accumulation and tolerance to Cd and Pb were further demonstrated through the hydroponic-culture method. And A. rosea had a great potential as a possible Cd hyperaccumulator under favorable or induced conditions. Furthermore, the interactive effects of Cd and Pb in the three ornamentals were complicated, not only additive, antagonistic or synergistic, but also related to many factors including concentration combinations of heavy metals, plant species and various parts of plants. Thus, it can be forecasted that this work will provide a new way for phytoremediation of contaminated soils.

Assessment of the Effectiveness of Environmental Dredging in South Lake, China

NASA Astrophysics Data System (ADS)

Wang, Xiao Yu; Feng, Jiang

2007-08-01

Environmental dredging is a primary remedial option for removal of the contaminated material from aquatic environment. Of primary concern in environmental dredging is the effectiveness of the intended sediment removal. A 5-year field monitoring study was conducted to assess the effectiveness of the environmental dredging in South Lake, China. The concentrations of total nitrogen (TN), total phosphors, and heavy metals (Zn, Pb, Cd, Cu, Cr, Ni, Hg, and As) before and after dredging in sediment were determined and compared. Multiple ecological risk indices were employed to assess the contamination of heavy metals before and after dredging. Our results showed that the total phosphorus levels reduced 42% after dredging. Similar changes for Hg, Zn, As Pb, Cd, Cu, Cr, and Ni were observed, with reduction percentages of 97.0, 93.1, 82.6, 63.9, 52.7, 50.1, 32.0, and 23.6, respectively, and the quality of sediment improved based on the criterion of Sediment Quality Guidelines by USEPA and contamination degree values (Cd) decreased significantly (paired t-test, p < 0.05). Unexpectedly, the TN increased 49% after dredging compared to before dredging. Findings from the study demonstrated that the environmental dredging was an effective mechanism for removal of total phosphorus and heavy metals from South Lake. Nevertheless, the dredging was ineffective to remove total nitrogen from sediment. We conclude that the reason for the observed increase in TN after dredging was likely ammonia release from the sediment impairing the dredging effectiveness.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Pragati, E-mail: pkumar.phy@gmail.com; Department of Physics and Astrophysics, University of Delhi, Delhi, 110 007; Saxena, Nupur

This work shows the influence of Ag concentration on structural properties of pulsed laser deposited nanocrystalline CdS thin film. X-ray photoelectron spectroscopy (XPS) studies confirm the dopant concentration in CdS films and atomic concentration of elements. XPS studies show that the samples are slightly sulfur deficient. GAXRD scan reveals the structural phase transformation from cubic to hexagonal phase of CdS without appearance of any phase of CdO, Ag{sub 2}O or Ag{sub 2}S suggesting the substitutional doping of Ag ions. Photoluminescence studies illustrate that emission intensity increases with increase in dopant concentration upto 5% and then decreases for higher dopant concentration.

Effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein and behavioural responses of abruptly weaned and housed beef calves

PubMed Central

2012-01-01

Background The effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein response, metabolic and behavioural response, and performance of abruptly weaned and housed beef calves was investigated. Calves were grazed with their dams until the end of the grazing season when they were weaned and housed (day (d) 0) in a concrete slatted floor shed, and offered grass silage ad libitum plus supplementary concentrates. Twenty-six days prior to weaning and housing, 20 singled suckled, pure-bred Simmental male (non-castrated), (n = 10, m) and female (n = 10, f) calves were assigned to one of two treatments (i) concentrate supplement (CS: n = 10 (5 m and 5 f), mean age (s.d.) 201 (12.8) d, mean weight (s.d.) 258 (20.2) kg) or (ii) no concentrate supplement (controls) (NCS: n = 10, (5 m and 5 f), mean age (s.d.) 201 (13.4) d, mean weight (s.d.) 257 (19.6) kg) pre-weaning. Results There was a treatment × sampling time interaction (P < 0.05) for percentage CD4+ and WC1+ (γδ T cells) lymphocytes and concentration of plasma globulin. On d 2, percentage CD4+ lymphocytes decreased (P < 0.001) in both treatments. Subsequently on d 7, percentage of CD4+ lymphocytes increased (P < 0.01) in CS compared with d 0, whereas percentage of CD4+ lymphocytes in NCS did not differ (P > 0.05) from d 0. On d 2, WC1+ lymphocytes decreased (P < 0.05) in both treatments but the decrease was greater (P <0.05) in NCS than CS. Subsequently, percentages did not differ (P > 0.05) from pre-weaning baseline. On d 2, the increase in concentration of globulin was greater (P < 0.05) in CS compared with NCS, and subsequently there was no difference between treatments. Pre-weaning ADG was 1.07 (s.e.m.) (0.26) kg and 0.99 (s.e.m.) (0.26) kg for CS and NCS, respectively. Post-weaning, CS calves spent more time lying compared with NCS calves. Conclusions Calves supplemented with concentrate prior to weaning had a lesser reduction in WC1+ lymphocytes, increased percentage CD4+ lymphocytes and concentration of total protein, and spent more time lying post-weaning, compared with non-supplemented calves. PMID:22217360

Bioaccessibility and Human Exposure Assessment of Cadmium and Arsenic in Pakchoi Genotypes Grown in Co-Contaminated Soils

PubMed Central

Wei, Yanyan; Zheng, Xiaoman; Shohag, Md. Jahidul Islam; Gu, Minghua

2017-01-01

In many countries cadmium (Cd) and arsenic (As) commonly coexist in soils contaminated by mining activities, and can easily enter the human body via consumption of leafy vegetables, like the popularly consumed pakchoi (Brassica chinensis L.), causing major health concerns. In the present study, bioaccessibility and human exposure of Cd and As were assessed in twenty genotypes of pakchoi cultured at two different levels of co-contamination to identify low health risk genotypes. The bioaccessibilities of Cd and As represent a fraction of the total metals content could be bioaccessible for human, in the present study, significant differences in pakchoi Cd and As bioaccessibility were observed among all tested genotypes and co-contaminated levels. Cd and As bioaccessibility of pakchoi were in the ranges of 24.0–87.6% and 20.1–82.5%, respectively, for in the high level co-contaminated soils, which was significantly higher than for low level co-contaminated soils with 7.9–71.8% for Cd bioaccessibility and 16.1–59.0% for As bioaccessibility. The values of bioaccessible established daily intakes (BEDI) and the total bioaccessible target hazard quotients (TBTHQ) of Cd and As were also considerably higher in high level co-contaminated soils than in low level co-contaminated soils. Two genotypes (Meiguanqinggengcai and Zhenqing60F1) contained relatively low concentrations and bioaccessible Cd and As and, their BEDI and TBTHQ for Cd and As ranged below the tolerable limits set by the FAO/WHO (BEDI of Cd < 0.83 μg kg−1 bw day−1, BEDI of As < 3 μg kg−1 bw day−1) and United States Environmental Protection Agency (TBTHQ for Cd and As < 1), this applied for both levels of co-contaminated soils for adults and children. Consequently, these findings suggest identification of safe genotypes in leafy vegetable with low health risk via genotypic screening and breeding methods could be a useful strategy to ensure the safety of food crops grown in those Cd and As co-contaminated fields due to mining activities. PMID:28850097

Bioaccessibility and Human Exposure Assessment of Cadmium and Arsenic in Pakchoi Genotypes Grown in Co-Contaminated Soils.

PubMed

Wei, Yanyan; Zheng, Xiaoman; Shohag, Md Jahidul Islam; Gu, Minghua

2017-08-29

In many countries cadmium (Cd) and arsenic (As) commonly coexist in soils contaminated by mining activities, and can easily enter the human body via consumption of leafy vegetables, like the popularly consumed pakchoi ( Brassica chinensis L.), causing major health concerns. In the present study, bioaccessibility and human exposure of Cd and As were assessed in twenty genotypes of pakchoi cultured at two different levels of co-contamination to identify low health risk genotypes. The bioaccessibilities of Cd and As represent a fraction of the total metals content could be bioaccessible for human, in the present study, significant differences in pakchoi Cd and As bioaccessibility were observed among all tested genotypes and co-contaminated levels. Cd and As bioaccessibility of pakchoi were in the ranges of 24.0-87.6% and 20.1-82.5%, respectively, for in the high level co-contaminated soils, which was significantly higher than for low level co-contaminated soils with 7.9-71.8% for Cd bioaccessibility and 16.1-59.0% for As bioaccessibility. The values of bioaccessible established daily intakes (BEDI) and the total bioaccessible target hazard quotients (TBTHQ) of Cd and As were also considerably higher in high level co-contaminated soils than in low level co-contaminated soils. Two genotypes (Meiguanqinggengcai and Zhenqing60F1) contained relatively low concentrations and bioaccessible Cd and As and, their BEDI and TBTHQ for Cd and As ranged below the tolerable limits set by the FAO/WHO (BEDI of Cd < 0.83 μg kg -1 bw day -1 , BEDI of As < 3 μg kg -1 bw day -1 ) and United States Environmental Protection Agency (TBTHQ for Cd and As < 1), this applied for both levels of co-contaminated soils for adults and children. Consequently, these findings suggest identification of safe genotypes in leafy vegetable with low health risk via genotypic screening and breeding methods could be a useful strategy to ensure the safety of food crops grown in those Cd and As co-contaminated fields due to mining activities.

Chemical fractionation of metals in wetland sediments: Indiana Dunes National Lakeshore.

PubMed

Dollar, N L; Souch, C J; Filippelli, G M; Mastalerz, M

2001-09-15

Tessier-type (1979) sequential extractions for heavy metals (Cd, Cr, Cu, Fe, Mn, Pb, and Zn) were conducted on sediments from two wetland sites, one inundated and the other drained, within the Indiana Dunes National Lakeshore (IDNL), NW Indiana, with the objective of (i) evaluating extraction techniques on organic-rich sediments, (ii) determining the geochemistry and mobility of potentially biotoxic trace metals in a contaminated environment, and (iii) considering the implications of different restoration strategies on the potential for heavy metal remobilization. Long and repeated extractions were needed to effectively degrade the organic-rich sediments (up to 75% of the sediment by mass). Analysis of sulfur fractionation revealed that it was predominantly sequestered along with the organically bound fraction (renamed oxidizable). Metal recovery was good with the sum of the extractant steps typically within 20% of the total metal concentration determined after total microwave digestion. Results showed metal fractionation to be both metal- and site-specific, The oxidizable fraction is dominant for Cu, Cr, and Fe (>65% of the nonresidual fraction for almost all samples) and overall is most important also for Cd and Pb. The iron/manganese oxide fraction is important for Pb, Mn, and Zn, particularly at the drained site. The carbonate bound fraction is relatively insignificant at both sites, except for Cd and Mn, although it is more important at the drained site. The exchangeable fraction is significant in the uppermost sediments at the drained site, particularly for Cd (3-24%), Pb (3-14%), and Zn (36-45%); whereas, for the inundated site, it ranged only from 0 to 1% Zn, with no detectable Cd or Pb. Chromium, Cu, and Fe exist in forms not likely to be remobilized, whereas Cd, Mn, Pb, and Zn are potentially mobile if drained wetland sites are reflooded (and pH and redox potential altered). Simple mass balance calculations illustrate the potential for the removal of approximately 84,375 kg of exchangeable Zn if currently drained sites across the IDNL are reflooded, with concentrations in water draining into Lake Michigan as high as 5 ppm.

Risk Assessment of Heavy Metals in Surface Sediments from the Yanghe River, China

PubMed Central

Li, Jing

2014-01-01

The magnitude and ecological relevance of metal pollution from the upstream of water sources after emergency pollution events was investigated by applying a set of complementary sediment quality assessment methods: (1) geochemical assessment based on background value (the geoaccumulation index); (2) comparisons with sediment quality guidelines (SQGs); (3) an evaluation of the combined pollution according to the risk index (RI); and (4) investigation of the chemical patterns of target heavy metals (Cd, Zn, Cr, Pb, Ni). The geoaccumulation indices (Igeo) suggested that the magnitude of heavy metal pollution of the sediment of Yanghe River decreased in the order of Cd > Zn > Pb > Cr > Ni. Risk analysis also suggested that Cd and Zn concentrations were sufficiently elevated as to cause adverse biological effects in this study area. According to the RI values, 27% of total sampling sites showed considerable ecological risk for the water body, and 53% of total sampling sites showed very high ecological risk for the waterbody. Sediment-bound Cd was found to be predominantly associated with the exchangeable phase of the sediment (25%–68%), while Cr, Ni, Zn and Pb showed the strongest association with the residual fractions (60%–92%, 53%–67%, 24%–85% and 35%–67%, respectively). PMID:25464136

Mobility and bioavailability of Cd, Co, Cr, Cu, Mn and Zn in surface runoff sediments in the urban catchment area of Guwahati, India

NASA Astrophysics Data System (ADS)

Devi, Upama; Bhattacharyya, Krishna G.

2018-03-01

The sediments in stormwater runoff are recognised as the major sink of the heavy metals and affect the soil quality in the catchment. The runoff sediments are also important in the management of contaminant transport to receiving water bodies. In the present work, stormwater during several major rain events was collected from nine principal locations of Guwahati, India. The solid phase was separated from the liquid phase and was investigated for the total contents of Cd, Co, Cr, Cu, Mn and Zn as well as their distribution among the prominent chemical phases. Sequential extraction procedure was used for the chemical fractionation of the metals that contains five steps. The total metal concentration showed the trend, Cd < Co < Cu < Cr < Zn < Mn. The relative distribution of the metals showed that Cd was available mostly in the exchangeable and the carbonate bound fractions, which were the most mobile and high-risk fractions. Co with medium mobility was also found to be in the high-risk category. On the other hand, the mobilities of Cu and Zn were relatively low and these were, therefore, the least bioavailable metals in the runoff sediments falling in medium-risk category.

Assessment of natural sepiolite on cadmium stabilization, microbial communities, and enzyme activities in acidic soil.

PubMed

Sun, Yuebing; Sun, Guohong; Xu, Yingming; Wang, Lin; Liang, Xuefeng; Lin, Dasong; Hu, Fazhi

2013-05-01

A pot trial was conducted to assess the efficiency of sepiolite-induced cadmium (Cd) immobilization in ultisoils. Under Cd concentrations of 1.25, 2.5, and 5 mg kg(-1), the available Cd in the soil after the application of 1-10 % sepiolite decreased by a maximum of 44.4, 23.0, and 17.0 %, respectively, compared with no sepiolite treatments. The increase in the values of soil enzyme activities and microbial number proved that a certain metabolic recovery occurred after sepiolite treatment. The dry biomass of spinach (Spinacia oleracea) increased with increasing sepiolite concentration in the soil. However, the concentration (dry weight) of Cd in the spinach shoots decreased with the increase in sepiolite dose, with maximum reduction of 92.2, 90.0, and 84.9 %, respectively, compared with that of unamended soils. Under a Cd level of 1.25 mg kg(-1), the Cd concentration in the edible parts of spinach at 1 % sepiolite amendment was lower than 0.2 mg kg(-1) fresh weight, the maximum permissible concentration (MPC) of Cd in vegetable. Even at higher Cd concentrations (2.5 and 5 mg kg(-1)), safe spinach was produced when the sepiolite treatment was up to 5 %. The results showed that sepiolite-assisted remediation could potentially succeed on a field scale by decreasing Cd entry into the food chain.

Distribution of Cd, Pb and Cu between dissolved fraction, inorganic particulate and phytoplankton in seawater of Terra Nova Bay (Ross Sea, Antarctica) during austral summer 2011-12.

PubMed

Illuminati, S; Annibaldi, A; Romagnoli, T; Libani, G; Antonucci, M; Scarponi, G; Totti, C; Truzzi, C

2017-10-01

During the austral summer 2011-2012, the metal quotas of Cd, Pb and Cu in the phytoplankton of Terra Nova Bay (TNB, Antarctica) were measured for the first time. Evolution of all the three metal distributions between dissolved and particulate fractions during the season was also evaluated. Metal concentrations were mainly affected by the dynamic of the pack ice melting and phytoplankton activity. In mid-December when TNB area was covered by a thick pack ice layer and phytoplankton activity was very low, all the three metals were present mainly in their dissolved species. When the pack ice started to melt and the water column characteristics became ideal (i.e. moderate stratification, ice free area), the phytoplankton bloom occurred. Cd showed a nutrient-type behaviour with dissolved and particulate fractions mainly influenced by phytoplankton activity. Cd quota showed a mean value of 0.12 ± 0.07 nmol L -1 (30-100% of the total particulate). Also Cu showed a nutrient-type behaviour, with its quota in phytoplankton varying between 0.08 and 2.1 nmol L -1 (20-100% of the total particulate). Pb features the typical distribution of a scavenged element with very low algal content (0.03 ± 0.02 nmol L -1 , representing 20-50% of the total particulate). The vertical distribution of this element was influenced by several factors (e.g. pack ice melting, atmospheric inputs), the phytoplankton activity affecting Pb behaviour only partially. Metal:C ratios provide valuable information on the biological requirements for Cd, Pb and Cu, leading us to better understand their biogeochemical cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mercury, Cadmium, and Lead Levels in Human Placenta: A Systematic Review

PubMed Central

Esteban-Vasallo, María D.; Aragonés, Nuria; Pollan, Marina; López-Abente, Gonzalo

2012-01-01

Background: Placental tissue may furnish information on the exposure of both mother and fetus. Mercury (Hg), cadmium (Cd), and lead (Pb) are toxicants of interest in pregnancy because they are associated with alterations in child development. Objectives: The aim of this study was to summarize the available information regarding total Hg, Cd, and Pb levels in human placenta and possible related factors. Methods: We performed a systematic search of PubMed/MEDLINE, EMBASE, Lilacs, OSH, and Web of Science for original papers on total Hg, Cd, or Pb levels in human placenta that were published in English or Spanish (1976–2011). Data on study design, population characteristics, collection and analysis of placenta specimens, and main results were extracted using a standardized form. Results: We found a total of 79 papers (73 different studies). Hg, Cd, and Pb levels were reported in 24, 46, and 46 studies, respectively. Most studies included small convenience samples of healthy pregnant women. Studies were heterogeneous regarding populations selected, processing of specimens, and presentation of results. Hg concentrations > 50 ng/g were found in China (Shanghai), Japan, and the Faroe Islands. Cd levels ranged from 1.2 ng/g to 53 ng/g and were highest in the United States, Japan, and Eastern Europe. Pb showed the greatest variability, with levels ranging from 1.18 ng/g in China (Shanghai) to 500 ng/g in a polluted area of Poland. Conclusion: The use of the placenta as a biomarker to assess heavy metals exposure is not properly developed because of heterogeneity among the studies. International standardized protocols are needed to enhance comparability and increase the usefulness of this promising tissue in biomonitoring studies. PMID:22591711

Polymorphisms in Iron Homeostasis Genes and Urinary Cadmium Concentrations among Nonsmoking Women in Argentina and Bangladesh

PubMed Central

Rentschler, Gerda; Kippler, Maria; Axmon, Anna; Raqib, Rubhana; Ekström, Eva-Charlotte; Skerfving, Staffan; Vahter, Marie

2013-01-01

Background: Cadmium (Cd) is a human toxicant and carcinogen. Genetic variation might affect long-term accumulation. Cd is absorbed via iron transporters. Objectives: We evaluated the impact of iron homeostasis genes [divalent metal transporter 1 (SLC11A2), transferrin (TF), transferrin receptors (TFR2 and TFRC), and ferroportin (SLC40A1)] on Cd accumulation. Methods: Subjects were nonsmoking women living in the Argentinean Andes [n = 172; median urinary Cd (U-Cd) = 0.24 µg/L] and Bangladesh (n = 359; U-Cd = 0.54 µg/L) with Cd exposure mainly from food. Concentrations of U-Cd and Cd in whole blood or in erythrocytes (Ery-Cd) were measured by inductively coupled plasma mass spectrometry. Fifty polymorphisms were genotyped by Sequenom. Gene expression was measured in whole blood (n = 72) with Illumina DirectHyb HumanHT-12 v4.0. Results: TFRC rs3804141 was consistently associated with U-Cd. In the Andean women, mean U-Cd concentrations were 22% (95% CI: –2, 51%), and they were 56% (95% CI: 10, 120%) higher in women with GA and AA genotypes, respectively, relative to women with the GG genotype. In the Bangladeshi women, mean U-Cd concentrations were 22% (95% CI: 1, 48%), and they were 58% (95% CI: –3, 157%) higher in women with GA and AA versus GG genotype, respectively [adjusted for age and plasma ferritin in both groups; ptrend = 0.006 (Andes) and 0.009 (Bangladesh)]. TFRC expression in blood was negatively correlated with plasma ferritin (rS = –0.33, p = 0.006), and positively correlated with Ery-Cd (significant at ferritin concentrations of < 30 µg/L only, rS = 0.40, p = 0.046). Rs3804141 did not modify these associations or predict TFRC expression. Cd was not consistently associated with any of the other polymorphisms evaluated. Conclusions: One TFRC polymorphism was associated with urine Cd concentration, a marker of Cd accumulation in the kidney, in two very different populations. The consistency of the findings supports the possibility of a causal association. PMID:23416510

[Phytoremediation of mercury and cadmium polluted wetland by Arundo donax].

PubMed

Han, Zhiping; Hu, Xiaobin; Hu, Zhenghai

2005-05-01

With a pot culture of simulated mercury (Hg) and cadmium (Cd)-polluted wetland, this paper studied the capability of Arundo donax in accumulating these heavy metals, and their distribution in the plant. The results showed that after grown in a 101 mg.kg(-1) Hg-polluted wetland for 8 months, the Hg-concentrating capability of Arundo donax was in order of root > stem > leaf, and the Hg concentration in its aboveground parts was 200 +/- 20 mg.kg(-1) (DW); while in the case of 115 mg.kg(-1) Cd-pollution, the Cd-concentrating capability was in order of leaf > root > stem, and the Cd concentration in leaf was 160 +/- 26 mg.kg(-1) (DW). The heavy metals concentration in Arundo donax organs increased with its growth time, being 30%-50% higher for 8 months than for 4 months. The BCF (Bio-concentration factor) decreased with increasing heavy metals concentration. In polluted wetland, the BCFs of Hg by the leaf and stem were 1.9 and 2.1, and those of Cd were 1.5 and 0.3, respectively; while in unpolluted wetland, the concentration of Hg and Cd was 6.8 and 8.5 mg.kg(-1), the BCFs of Hg by the leaf and stem were 6.8 and 12.2, and those of Cd were 7.0 and 2.7, respectively. It was indicated that Arundo donax not only had the characters of large biomass, exuberant root, and good adaptability, but also exhibited high tolerance and concentrating capability to Cd and Hg.

Involvement of an antioxidant defense system in the adaptive response to cadmium in maize seedlings (Zea mays L.).

PubMed

Xu, Xianghua; Liu, Cuiying; Zhao, Xiaoyan; Li, Renying; Deng, Wenjing

2014-11-01

Chemical and biological analyses were used to investigate the growth response and antioxidant defense mechanism of maize seedlings (Zea mays L.) grown in soils with 0-100 mg kg(-1) Cd. Results showed that maize seedlings have strong abilities to accumulate and tolerate high concentrations of Cd. For soil with 50 mg kg(-1) Cd, the Cd contents in roots and shoots of maize seedlings are as large as 295.6 and 153.0 mg kg(-1) DW, respectively, without visible symptoms of toxicity. Lower soil Cd concentrations lead to a decrease in reduced glutathione (GSH) content in leaves of maize seedlings, whereas higher soil Cd concentrations resulted in an increase in the activities of superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Maize seedlings have strong capacities to adapt to low concentrations of Cd by consuming GSH and to develop an antioxidative enzyme system to defend against high-Cd stress.

Successive Onset of Molecular, Cellular and Tissue-Specific Responses in Midgut Gland of Littorina littorea Exposed to Sub-Lethal Cadmium Concentrations

PubMed Central

Benito, Denis; Izagirre, Urtzi; Dallinger, Reinhard; Soto, Manu

2017-01-01

Cadmium (Cd) is one of the most harmful metals, being toxic to most animal species, including marine invertebrates. Among marine gastropods, the periwinkle (Littorina littorea) in particular can accumulate high amounts of Cd in its midgut gland. In this organ, the metal can elicit extensive cytological and tissue-specific alterations that may reach, depending on the intensity of Cd exposure, from reversible lesions to pathological cellular disruptions. At the same time, Littorina littorea expresses a Cd-specific metallothionein (MT) that, due to its molecular features, expectedly exerts a protective function against the adverse intracellular effects of this metal. The aim of the present study was, therefore, to assess the time course of MT induction in the periwinkle’s midgut gland on the one hand, and cellular and tissue-specific alterations in the digestive organ complex (midgut gland and digestive tract) on the other, upon exposure to sub-lethal Cd concentrations (0.25 and 1 mg Cd/L) over 21 days. Depending on the Cd concentrations applied, the beginning of alterations of the assessed parameters followed distinct concentration-dependent and time-dependent patterns, where the timeframe for the onset of the different response reactions became narrower at higher Cd concentrations compared to lower exposure concentrations. PMID:28829377

The possible role of direct ingestion on the overall absorption of cadmium or arsenic in workers exposed to CdO or As2O3 dust.

PubMed

Roels, H; Buchet, J P; Truc, J; Croquet, F; Lauwerys, R

1982-01-01

Six volunteers (two office and four cadmium (Cd)-exposed workers, all nonsmokers) from an electric condenser factory participated in a study involving the measurement of cadmium in air and in dust, the evaluation of hand and mouth contamination by cadmium, and the determination of fecal cadmium. The mean levels of total airborne cadmium measured with static and personal samplers were for the exposed workers 9.5 and 16.7 microgram/m3, respectively, and for the office workers 0.3 and 0.5 microgram/m3, respectively. In the office workers, hand contamination by Cd hardly changes over the workday (less than 10 microgram/hand), whereas in the exposed workers important hand contamination by Cd was observed (up to 1,200 microgram/hand during the workday and up to 300 microgram/hand before lunch or before leaving the factory). Mouth contamination by Cd is rather similar in both groups on Monday morning, but increases 20- to 50-fold on Friday afternoon in the Cd workers against a slight increase for the office workers. The concentration of Cd in the feces was not much different between Sunday and Friday in the office workers, whereas in the exposed workers it was higher on Friday than on Sunday. There is suggestive evidence from a comparative study of fecal cadmium in two Cd-exposed volunteers who carried out their jobs with and without gloves that direct cadmium intake from hand contamination may contribute to the overall Cd absorption. A limited study in a glassware factory (As2O3 exposure) involving the measurement of total airborne arsenic, the determination of urinary arsenic, and the evaluation of hand and mouth contamination by arsenic before and after the workshift suggests that the high urinary arsenic levels (300 microgram/g creatinine) are likely to be more related to an increased oral intake from contaminated hands than to an increased absorption from the lungs.

Fractionation and ecological risk of metals in urban river sediments in Zhongshan City, Pearl River Delta.

PubMed

Cai, Jiannan; Cao, Yingzi; Tan, Haijian; Wang, Yanman; Luo, Jiaqi

2011-09-01

Surface sediments collected from nine urban rivers located in Zhongshan City, Pearl River Delta, were analyzed for total concentration of metals with digestion and chemical fractionation adopting the modified European Community Bureau of Reference (BCR) sequential extraction procedure. The results showed that concentration and fractionation of metals varied significantly among the rivers. The total concentration of eight metals in most rivers did not exceed the China Environmental Quality Standard for Soil, Grade III. The potential ecological risk of metals to rivers were related to the land use patterns, in the order of manufacturing areas > residential areas > agriculture areas. The concentration of Pb in the reducible fraction was relatively high (60.0-84.3%). The dominant proportions of Cd, Zn and Cu were primary in the non-residual fraction (67.0%, 71.8% and 81.4% on average respectively), while the percentages of the residual fractions of Cr and Ni varied over a wide range (43-85% and 24-71% respectively). The approaches of the Håkanson ecological risk index and Secondary Phase Enrichment Factor were applied for ecological risk assessment and metal enrichment calculation. The results indicated Hg and Cd had posed high potential ecological risk to urban rivers in this region. Meanwhile, there was widespread pollution and high enrichment of Cu in river sediments in this region. Multiple regression analysis showed that five water quality parameters (pH, DO, COD(Mn), NH(4)(+)-N, TP) had little influence on the distribution of metal fractionation. This result revealed that the ecological risk of metals was not eliminated along with the improvement in water quality. Correlation studies showed that among the metals, Group A (Cd, As, Pb, Zn Hg, r = 0.730-0.924) and Group B (Cr, Cu, Ni, r = 0.815-0.948) were obtained, and the metal contaminations were from industrial activities rather than residential.

Assessment of metals bioavailability to vegetables under field conditions using DGT, single extractions and multivariate statistics

PubMed Central

2012-01-01

Background The metals bioavailability in soils is commonly assessed by chemical extractions; however a generally accepted method is not yet established. In this study, the effectiveness of Diffusive Gradients in Thin-films (DGT) technique and single extractions in the assessment of metals bioaccumulation in vegetables, and the influence of soil parameters on phytoavailability were evaluated using multivariate statistics. Soil and plants grown in vegetable gardens from mining-affected rural areas, NW Romania, were collected and analysed. Results Pseudo-total metal content of Cu, Zn and Cd in soil ranged between 17.3-146 mg kg-1, 141–833 mg kg-1 and 0.15-2.05 mg kg-1, respectively, showing enriched contents of these elements. High degrees of metals extractability in 1M HCl and even in 1M NH4Cl were observed. Despite the relatively high total metal concentrations in soil, those found in vegetables were comparable to values typically reported for agricultural crops, probably due to the low concentrations of metals in soil solution (Csoln) and low effective concentrations (CE), assessed by DGT technique. Among the analysed vegetables, the highest metal concentrations were found in carrots roots. By applying multivariate statistics, it was found that CE, Csoln and extraction in 1M NH4Cl, were better predictors for metals bioavailability than the acid extractions applied in this study. Copper transfer to vegetables was strongly influenced by soil organic carbon (OC) and cation exchange capacity (CEC), while pH had a higher influence on Cd transfer from soil to plants. Conclusions The results showed that DGT can be used for general evaluation of the risks associated to soil contamination with Cu, Zn and Cd in field conditions. Although quantitative information on metals transfer from soil to vegetables was not observed. PMID:23079133

Positive association between concentration of phthalate metabolites in urine and microparticles in adolescents and young adults.

PubMed

Lin, Chien-Yu; Hsieh, Chia-Jung; Lo, Shyh-Chyi; Chen, Pau-Chung; Torng, Pao-Ling; Hu, Anren; Sung, Fung-Chang; Su, Ta-Chen

2016-01-01

Di-(2-ethylhexyl) phthalate (DEHP) has been used worldwide in various products for many years. In vitro studies have shown that exposure to DEHP and its metabolite mono(2-ethylhexyl) phthalate (MEHP) induces endothelial cell apoptosis. Moreover, exposure to DEHP had been linked to cardiovascular risk factors and cardiovascular diseases in epidemiological studies. Circulating microparticles have been known to be indicators of vascular injury. However, whether DEHP or its metabolites are independently associated with microparticles in humans remains unknown. From 2006 to 2008, we recruited 793 subjects (12-30years) from a population-based sample to participate in this cardiovascular disease prevention examination. Each participant was subjected to interviews and biological sample collection to determine the relationship between concentrations of DEHP metabolites MEHP, mono(ethyl-5-hydroxyhexyl) phthalate, and mono(2-ethly-5-oxoheyl) phthalate in urine and concentrations of endothelial microparticles (CD62E and CD31+/CD42a-), platelet microparticles (CD62P and CD31+/CD42a+), and CD14 in serum. Multiple linear regression analysis revealed that an ln-unit increase in MEHP concentration in urine was positively associated with an increase in serum microparticle counts/μL of 0.132 (±0.016) in CD31+/CD42a- (endothelial apoptosis marker), 0.117 (±0.023) in CD31+/CD42a+ (platelet apoptosis marker), and 0.026 (±0.007) in CD14 (monocyte, macrophage, and neutrophil activation marker). There was no association between DEHP metabolite concentration and CD62E or CD62P. In conclusion, a higher MEHP concentration in urine was associated with an increase in endothelial and platelet microparticles in this cohort of adolescents and young adults. Further studies are warranted to clarify the causal relationship between exposure to DEHP and atherosclerosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sexually immature male ERE-Luc reporter mice to assess low dose estrogen-like effects of CdCl2 versus dietary Cd

PubMed Central

Ramachandran, Balaji; Rizzi, Nicoletta; Maggi, Adriana

2014-01-01

CdCl2 salt is widely used in exposure oriented studies, while the biological exposure of Cadmium (Cd) occurs mostly through diet. Hence, we designed a in vivo imaging methodology with sexually immature male ERE-Luc reporter mice to test the estrogen-like (EL) effects of Cd as a natural component in wheat and flax bread based diets (containing 17.57 and 49.22 ug/kg Cd concentrations respectively) and CdCl2 per-oral dose of 1 ug/kg/bw/day. Total exposure of ingested and % bioaccumulation of Cd in selected organs were estimated as 547 ng (4.4%), 776 ng (0.3%) and 2131.8 ng (0.1%) corresponding to CdCl2, wheat and flax bread based diet treatments respectively. Cd from CdCl2 bioaccumulated more readily, despite the exposure of Cd is higher with bread based diets. Longitudinal in vivo imaging did not reveal significant changes in luciferase activity. White adipose tissue (WAT) and prostate were identified as novel target organs of Cd. Indeed, the rest of the observed EL effects, endogenous target gene expression and necropsy findings are not consistent to any particular organ or treatment. This implies that, the observed EL effects due to low doses of Cd (either from CdCl2 or dietary form) occur only as subtle changes at the molecular level, but inadequate to cause significant changes at the anatomo-pathological level during the 21 day exposure period. The study demonstrates the sensitivity of the methodology to assess EL effects of food embedded Cd and underlines the limitations of directly extrapolating the results of suspected chemicals in their pure form to dietary exposure scenarios. PMID:24795841

T-cell immunity and cytokine production in cosmonauts after long-duration space flights

NASA Astrophysics Data System (ADS)

Morukov, B.; Rykova, M.; Antropova, E.; Berendeeva, T.; Ponomaryov, S.; Larina, I.

2011-04-01

Long-duration spaceflight effects on T-cell immunity and cytokine production were studied in 12 Russian cosmonauts flown onto the International Space Station. Specific assays were performed before launch and after landing and included analysis of peripheral leukocyte distribution, analysis of T-cell phenotype, expression of activation markers, apoptosis, proliferation of T cells in response to a mitogen, concentrations of cytokines in supernatants of cell cultures. Statistically significant increase was observed in leukocytes', lymphocytes', monocytes' and granulocytes' total number, increase in percentage and absolutely number of CD3 +CD4 +-cells, CD4 +CD45RA +-cells and CD4 +CD45RA +/CD4 +CD45RО + ratio, CD4 +CD25 +Bright regulatory cells ( p<0,05) in peripheral blood after landing. T-lymphocytes' capacity to present CD69 and CD25 on its own surfaces was increased for the majority of crewmembers. Analysis of T-cell response to PHA-stimulation in vitro revealed there were some trends toward reduced proliferation of stimulated T-lymphocytes. There was an apparent post flight decrease in secreted IFN-g for the majority of crewmembers and in most instances there was elevation in secreted IL-10. It revealed depression of IFN-g/IL-10 ratio after flight. Correlation analysis according to Spearman's rank correlation test established significant positive correlations ( p<0.05) between cytokine production and T-cell activation (CD25+, CD38+) and negative correlation ( p<0.05) between cytokine production and number of bulk memory CD4+T-cells (CD45RO+). Thus, these results suggest that T-cell dysfunction can be conditioned by cytokine dysbalance and could lead to development of disease after long-duration space flights.

Identification of cadmium-resistant fungi related to Cd transportation in bermudagrass [Cynodon dactylon (L.) Pers].

PubMed

Xie, Yan; Luo, Hongji; Du, Zhimin; Hu, Longxing; Fu, Jinmin

2014-12-01

Phytoremediation utilizing plants and microbes has been increasingly adopted as a green technology for cleaning up heavy metal polluted soils. Cd polluted soil and native bermudagrass from Liuyang and Zhuzhou in Hunan province of China were collected to investigate microbial diversity and isolate Cd resistant fungi, and then to determine the effect of Cd resistant fungi on Cd tolerance and transportation of bermudagrass. The functional diversity of microorganisms was evaluated using the BIOLOG Eco method. Cd-resistant fungi strain was isolated and identified as Aspergillus aculeatus based on the ribosomal internal transcribed spacer region sequence analysis. Bermudagrass was exposed to control, Cd only, and Cd plus A. aculeatus (Cd + A. aculeatus) with growth matrix (sawdust/sand = 3/1 in volume). Results indicated that Cd + A. aculeatus treated bermudagrass exhibited a higher photosynthetic activity compared to Cd only treated plants. Inoculation of A. aculeatus resulted in a decrease in stem and leaf Cd concentrations, to a greater extent for Cd-sensitive than for Cd-tolerant genotype. However, inoculation of A. aculeatus increased root Cd concentration under Cd stress conditions, significantly elevated soil pH, and decreased soil water-soluble Cd concentration. These results suggested that A. aculeatus might be potentially applied to improve Cd tolerance and to reduce Cd transportation to shoot of bermudagrass.

Comparative bioaccumulation of trace metals using six filter feeder organisms in a coastal lagoon ecosystem (of the central-east Gulf of California).

PubMed

Jara-Marini, M E; Tapia-Alcaraz, J N; Dumer-Gutiérrez, J A; García-Rico, L; García-Hernández, J; Páez-Osuna, F

2013-02-01

The Tobari Lagoon, located in the central-east coast of the Gulf of California, receives effluents from the Yaqui Valley, one of the most extensive agricultural areas of México. The Tobari Lagoon also receives effluents from nearby shrimp farms and untreated municipal sewage. Surface sediment samples and six different species of filter feeders (Crassostrea corteziensis, Crassostrea gigas, Chione gnidia, Anadara tuberculosa, Chione fluctifraga, and Fistulobalanus dentivarians) were collected during the dry and the rainy seasons and analyzed to determine concentrations of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). Seasonal variations in metal concentrations in sediment were evident, especially for Cd, Cu, Hg, and Zn. The total and bioavailable concentrations of the five metals are not elevated in comparison to other areas around the world. The percentages of bioavailable respect to total concentrations of the metals varied from 0.6 % in Hg to 50.2 % for Cu. In the organisms, Hg showed the lowest concentrations (ranged from 0.22 to 0.65 μg/g) while Zn showed the highest (ranged from 36.6 to 1,702 μg/g). Linear correlations between the levels of Cu, Pb, and Zn in the soft tissues of C. fluctifraga and C. gnidia, and A. tuberculosa and C. gnidia were found. Seasonal and interspecies variations in the metal levels in filter feeders were found; F. dentivarians, C. corteziensis, and C. gigas exhibited the highest levels, could be used as biomonitors of metals contamination in this area.

Concentrations of selected essential and non-essential elements in arctic fox (Alopex lagopus) and wolverines (Gulo gulo) from the Canadian Arctic.

PubMed

Hoekstra, P F; Braune, B M; Elkin, B; Armstrong, F A J; Muir, D C G

2003-06-20

Arctic fox (Alopex lagopus) and wolverine (Gulo gulo) tissues were collected in the Canadian Arctic from 1998 to 2001 and analyzed for various essential and non-essential elements. Several elements (Ag, Al, As, B, Ba, Be, Co, Cr, Mo, Ni, Sb, Sn, Sr, Tl, U and V) were near or below the detection limits in >95% arctic fox and wolverine samples. Concentrations of Cd, Cu, Fe, total Hg (THg), Mn, Pb, Se and Zn were quantifiable in >50% of the samples analyzed and reported herein. Hepatic elemental concentrations were not significantly different among arctic foxes collected at Ulukhaqtuuq (Holman), NT (n=13) and Arviat, NU (n=50), but were significantly greater than concentrations found in wolverine liver from Kugluktuk (Coppermine), NU (n=12). The mean (+/-1 S.E.) concentrations of Cd in kidney were also significantly greater in arctic fox (1.08+/-0.19 microg g(-1) wet wt.) than wolverine (0.67+/-0.18 microg g(-1) wet wt.). However, mean hepatic Cu concentrations (Ulukhaqtuuq: 5.5+/-0.64; Arviat: 7.1+/-0.49 microg g(-1) wet wt.) in arctic foxes were significantly lower than in wolverines (32+/-3.3 microg g(-1) wet wt.). Hepatic total Hg (THg) concentrations in arctic fox from this study were not significantly different from specimens collected in 1973, suggesting that THg concentrations have not changed dramatically over the past 30 years. The mono-methylmercury (MeHg) concentrations in selected (n=10) arctic fox liver samples from Arviat (0.14+/-0.07 microg g(-1) wet wt.) comprised 14% of THg. While the molar concentrations of THg were correlated with Se in arctic foxes and wolverines, the hepatic Hg/Se molar ratios were consistently lower than unity; suggesting that Se-mediated detoxification pathways of Hg are not overwhelmed at current exposure.

Cadmium Accumulation Characteristics in Turnip Landraces from China and Assessment of Their Phytoremediation Potential for Contaminated Soils.

PubMed

Li, Xiong; Zhang, Xiaoming; Yang, Ya; Li, Boqun; Wu, Yuansheng; Sun, Hang; Yang, Yongping

2016-01-01

Heavy metal (HM) pollution is a global environmental problem that threatens ecosystem and human health. Cadmium (Cd) pollution is the most prominent HM pollution type because of its high toxicity, strong migration, and the large polluted area globally. Phytoremediation of contaminated soil is frequently practiced because of its cost-effectiveness and operability and because it has no associated secondary pollution. High-accumulation plants, including those identified as hyperaccumulators, play an important role in phytoremediation. Therefore, screening of plants to identify hyperaccumulators is important for continued phytoremediation. In the present study, we investigated the Cd tolerance and accumulation capabilities of 18 turnip landraces from China under a soil experiment with known Cd level. The results indicated that turnip has a high capacity for Cd accumulation. Furthermore, significant differences in Cd tolerance and accumulation characteristics were found among different landraces when they grew at 50 mg kg -1 (dry weight) Cd concentration. Among the studied landraces, five turnip landraces met the requirements of Cd hyperaccumulators and three landraces were identified as potential candidates. However, the total Cd content accumulated by individual plant of different turnip landraces was dependent on both the Cd accumulation capacity and plant biomass. Compared with some reported Cd hyperaccumulators, turnip not only shows a high Cd-accumulation capacity but also has rapid growth and a wide distribution area. These advantages indicate that turnip may have considerable potential for phytoremediation of Cd-contaminated soil. Furthermore, the study also indicates that it is not advisable to consume turnip cultivated in an environment that exceeds safe Cd levels.

Cadmium uptake by plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haghiri, F.

Absorption of /sup 115m/Cd by soybean (Gylcine max l.) plants via foliar and root systems and translocation into the seed was determined. The uptake of /sup 115m/Cd by soybeans via the root system was more efficient than that of the foliar placement. Growth and Cd concentrations of soybean and wheat (Triticum aestivum l.) tops were influenced by soil-applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicitiy began to occur in both crops at the lowest level of soil applied Cd (2.5 ppM). With soybean plants, Cdmore » toxicity symptoms resembled fe chlorosis. For wheat plants there were no visual symptoms other than the studied growth. The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa l.) > radish top (Raphanus sativus l.) > celery stalk (Apium graveolens l.) > celery leaves greater than or equal to green pepper (Capsicum frutescens l.) > radish roots.« less

A novel approach to enhancement of surface properties of CdO films by using surfactant: dextrin

NASA Astrophysics Data System (ADS)

Sahin, Bünyamin; Bayansal, Fatih; Yüksel, Mustafa

2015-12-01

We studied the effect of an organic surfactant, dextrin, concentration on structural, morphological and optical properties of nanostructured CdO films deposited on glass substrates by using an easy and low-cost SILAR method. Microstructures of the nanostructured CdO films were optimized by adjusting dextrin concentration. XRD, SEM and UV-Vis Spectroscopy were used to study phase structure, surface morphology and optical properties of CdO films. Furthermore, effects of dextrin concentration on the surface roughness characteristics of CdO samples were reported. The results showed that the presence of organic surfactant highly affected the physical properties of CdO nanomaterials.