Biomedical Implications of Heavy Metals Induced Imbalances in Redox Systems

PubMed Central

Singh, Shweta; Siddiqi, Nikhat J.

2014-01-01

Several workers have extensively worked out the metal induced toxicity and have reported the toxic and carcinogenic effects of metals in human and animals. It is well known that these metals play a crucial role in facilitating normal biological functions of cells as well. One of the major mechanisms associated with heavy metal toxicity has been attributed to generation of reactive oxygen and nitrogen species, which develops imbalance between the prooxidant elements and the antioxidants (reducing elements) in the body. In this process, a shift to the former is termed as oxidative stress. The oxidative stress mediated toxicity of heavy metals involves damage primarily to liver (hepatotoxicity), central nervous system (neurotoxicity), DNA (genotoxicity), and kidney (nephrotoxicity) in animals and humans. Heavy metals are reported to impact signaling cascade and associated factors leading to apoptosis. The present review illustrates an account of the current knowledge about the effects of heavy metals (mainly arsenic, lead, mercury, and cadmium) induced oxidative stress as well as the possible remedies of metal(s) toxicity through natural/synthetic antioxidants, which may render their effects by reducing the concentration of toxic metal(s). This paper primarily concerns the clinicopathological and biomedical implications of heavy metals induced oxidative stress and their toxicity management in mammals. PMID:25184144

Demonstration of Removal, Separation, and Recovery of Heavy Metals from Industrial Wastestreams Using Molecular Recognition Technology (MRT)

DTIC Science & Technology

2002-11-01

Treatment Plant”, TM-2123-ENV, April 1995. 3. Ford, K.H., 1996, “ Heavy Metal Adsorption/ Biosorption Studies for Zero Discharge Industrial Wastewater...SEPARATION, AND RECOVERY OF HEAVY METALS FROM INDUSTRIAL WASTESTREAMS USING MOLECULAR RECOGNITION TECHNOLOGY (MRT) Final Report by Dr. Katherine...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER DEMONSTRATION OF REMOVAL, SEPARATION, AND RECOVERY OF HEAVY METALS FROM INDUSTRIAL WASTEWATERS USING

Comparison of inversion accuracy of soil copper content from vegetation indices under different spectral resolution

NASA Astrophysics Data System (ADS)

Sun, Zhongqing; Shang, Kun; Jia, Lingjun

2018-03-01

Remote sensing inversion of heavy metal in vegetation leaves is generally based on the physiological characteristics of vegetation spectrum under heavy metal stress, and empirical models with vegetation indices are established to inverse the heavy metal content of vegetation leaves. However, the research of inversion of heavy metal content in vegetation-covered soil is still rare. In this study, Pulang is chosen as study area. The regression model of a typical heavy metal element, copper (Cu), is established with vegetation indices. We mainly investigate the inversion accuracies of Cu element in vegetation-covered soil by different vegetation indices according to specific spectral resolutions of ASD (Analytical Spectral Device) and Hyperion data. The inversion results of soil copper content in the vegetation-covered area shows a good accuracy, and the vegetation indices under ASD spectral resolution correspond to better results.

Research Progress of Artificial Forest in the Remediation of Heavy Metal Contaminated Soils

NASA Astrophysics Data System (ADS)

Jiafang, MA; Guangtao, MENG; Liping, HE; Guixiang, LI

2017-01-01

(1) Remediation of soil contaminated by heavy metals has become a hot topic in the world, and phytoremediation technology is the most widely used. (2) In addition to traditional economic benefits, ecological benefits of artificial forest have been more and more important, which are very helpful to soil polluted with heavy metals in the environment. (3) The characteristics of heavy metal pollution of soil and plantations of repair mechanism have been reviewed, and the current mining areas, wetlands, urban plantations on heavy metal elements have enriched the research results. The purpose is to find a new path for governance of heavy metal soil pollution.

Analyses of Essential Elements and Heavy Metals by Using ICP-MS in Maternal Breast Milk from Şanlıurfa, Turkey.

PubMed

Kılıç Altun, Serap; Dinç, Hikmet; Temamoğulları, Füsun Karaçal; Paksoy, Nilgün

2018-01-01

Maternal breast milk is a unique biological matrix that contains essential micronutrients. Potentially heavy metals may also affect infants' health and growth through maternal breast milk. The purpose of this study was to determine and compare the essential elements and heavy metals of maternal breast milk of nursery mothers residing in Şanlıurfa province, Turkey. Maternal breast milk concentrations of sodium, magnesium, phosphorus, potassium, calcium, iron, copper, zinc, arsenic, and lead were analyzed in a random sample of the first time in urban and suburban nursery Turkish mothers ( n : 42). Eight essential elements and two heavy metals were analyzed using ICP-MS after microwave digestion. For bivariate analyses of variables, we use nonparametric Spearman's correlation coefficient test. The mean concentrations of essential elements and heavy metals were as follows: sodium 330 ± 417 mg/L, magnesium 32.6 ± 15.5 mg/L, phosphorus 156 ± 46.2 mg/L, potassium 488 ± 146 mg/L, calcium 193 ± 53.2 mg/L, iron 1.65 ± 1.43 mg/L, copper 0.54 ± 0.46 mg/L, zinc 2.89 ± 3.23 mg/L, arsenic < 1  μ g/L, and lead < 1  μ g/L. Concentrations of heavy metals in maternal breast milk may have the important implication that it is not affected by environmental pollution in this province. This study provides reliable information about maternal breast milk concentrations of nursery mothers residing in Şanlıurfa, Turkey, and also compares the relations between essential elements and socioeconomic conditions, residing areas, and using copper equipment for food preparation of which some have not previously been reported.

Analyses of Essential Elements and Heavy Metals by Using ICP-MS in Maternal Breast Milk from Şanlıurfa, Turkey

PubMed Central

2018-01-01

Maternal breast milk is a unique biological matrix that contains essential micronutrients. Potentially heavy metals may also affect infants' health and growth through maternal breast milk. The purpose of this study was to determine and compare the essential elements and heavy metals of maternal breast milk of nursery mothers residing in Şanlıurfa province, Turkey. Maternal breast milk concentrations of sodium, magnesium, phosphorus, potassium, calcium, iron, copper, zinc, arsenic, and lead were analyzed in a random sample of the first time in urban and suburban nursery Turkish mothers (n: 42). Eight essential elements and two heavy metals were analyzed using ICP-MS after microwave digestion. For bivariate analyses of variables, we use nonparametric Spearman's correlation coefficient test. The mean concentrations of essential elements and heavy metals were as follows: sodium 330 ± 417 mg/L, magnesium 32.6 ± 15.5 mg/L, phosphorus 156 ± 46.2 mg/L, potassium 488 ± 146 mg/L, calcium 193 ± 53.2 mg/L, iron 1.65 ± 1.43 mg/L, copper 0.54 ± 0.46 mg/L, zinc 2.89 ± 3.23 mg/L, arsenic < 1 μg/L, and lead < 1 μg/L. Concentrations of heavy metals in maternal breast milk may have the important implication that it is not affected by environmental pollution in this province. This study provides reliable information about maternal breast milk concentrations of nursery mothers residing in Şanlıurfa, Turkey, and also compares the relations between essential elements and socioeconomic conditions, residing areas, and using copper equipment for food preparation of which some have not previously been reported. PMID:29849639

A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars

NASA Astrophysics Data System (ADS)

Guillot, T.; Santos, N. C.; Pont, F.; Iro, N.; Melo, C.; Ribas, I.

2006-07-01

Context.Nine extrasolar planets with masses between 110 and 430 M_⊕ are known to transit their star. The knowledge of their masses and radii allows an estimate of their composition, but uncertainties on equations of state, opacities and possible missing energy sources imply that only inaccurate constraints can be derived when considering each planet separately.Aims.We seek to better understand the composition of transiting extrasolar planets by considering them as an ensemble, and by comparing the obtained planetary properties to that of the parent stars.Methods.We use evolution models and constraints on the stellar ages to derive the mass of heavy elements present in the planets. Possible additional energy sources like tidal dissipation due to an inclined orbit or to downward kinetic energy transport are considered.Results.We show that the nine transiting planets discovered so far belong to a quite homogeneous ensemble that is characterized by a mass of heavy elements that is a relatively steep function of the stellar metallicity, from less than 20 earth masses of heavy elements around solar composition stars, to up to ~100 M_⊕ for three times the solar metallicity (the precise values being model-dependant). The correlation is still to be ascertained however. Statistical tests imply a worst-case 1/3 probability of a false positive.Conclusions.Together with the observed lack of giant planets in close orbits around metal-poor stars, these results appear to imply that heavy elements play a key role in the formation of close-in giant planets. The large masses of heavy elements inferred for planets orbiting metal rich stars was not anticipated by planet formation models and shows the need for alternative theories including migration and subsequent collection of planetesimals.

Altering Genomic Integrity: Heavy Metal Exposure Promotes Transposable Element-Mediated Damage.

PubMed

Morales, Maria E; Servant, Geraldine; Ade, Catherine; Roy-Engel, Astrid M

2015-07-01

Maintenance of genomic integrity is critical for cellular homeostasis and survival. The active transposable elements (TEs) composed primarily of three mobile element lineages LINE-1, Alu, and SVA comprise approximately 30% of the mass of the human genome. For the past 2 decades, studies have shown that TEs significantly contribute to genetic instability and that TE-caused damages are associated with genetic diseases and cancer. Different environmental exposures, including several heavy metals, influence how TEs interact with its host genome increasing their negative impact. This mini-review provides some basic knowledge on TEs, their contribution to disease, and an overview of the current knowledge on how heavy metals influence TE-mediated damage.

Size distribution, characteristics and sources of heavy metals in haze episode in Beijing.

PubMed

Duan, Jingchun; Tan, Jihua; Hao, Jiming; Chai, Fahe

2014-01-01

Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and Cd were deeply studied considering their toxic effect on human being. Among these heavy metals, the levels of Mn, As and Cd exceeded the reference values of National Ambient Air Quality Standard (GB3095-2012) and guidelines of World Health Organization. By estimation, high percentage of atmospheric heavy metals in PM2.5 indicates it is an effective way to control atmospheric heavy metals by PM2.5 controlling. Pb, Cd, and Zn show mostly in accumulation mode, V, Mn and Cu exist mostly in both coarse and accumulation modes, and Ni and Cr exist in all of the three modes. Considering the health effect, the breakthrough rates of atmospheric heavy metals into pulmonary alveoli are: Pb (62.1%) > As (58.1%) > Cd (57.9%) > Zn (57.7%) > Cu (55.8%) > Ni (53.5%) > Cr (52.2%) > Mn (49.2%) > V (43.5%). Positive matrix factorization method was applied for source apportionment of studied heavy metals combined with some marker elements and ions such as K, As, SO4(2-) etc., and four factors (dust, vehicle, aged and transportation, unknown) are identified and the size distribution contribution of them to atmospheric heavy metals are discussed.

Community Heavy Metal Exposure, San Francisco, California

NASA Astrophysics Data System (ADS)

Chavez, A.; Devine, M.; Ho, T.; Zapata, I.; Bissell, M.; Neiss, J.

2008-12-01

Heavy metals are natural elements that generally occur in minute concentrations in the earth's crust. While some of these elements, in small quantities, are vital to life, most are harmful in larger doses. Various industrial and agricultural processes can result in dangerously high concentrations of heavy metals in our environment. Consequently, humans can be exposed to unsafe levels of these elements via the air we breathe, the water and food we consume, and the many products we use. During a two week study we collected numerous samples of sediments, water, food, and household items from around the San Francisco Bay Area that represent industrial, agricultural, and urban/residential settings. We analyzed these samples for Mercury (Hg), Lead (Pb), and Arsenic (As). Our goal was to examine the extent of our exposure to heavy metals in our daily lives. We discovered that many of the common foods and materials in our lives have become contaminated with unhealthy concentrations of these metals. Of our food samples, many exceeded the EPA's Maximum Contaminant Levels (MCL) set for each metal. Meats (fish, chicken, and beef) had higher amounts of each metal than did non-meat items. Heavy metals were also prevalent in varying concentrations in the environment. While many of our samples exceeded the EPA's Sediment Screening Level (SSL) for As, only two other samples surpassed the SSL set for Pb, and zero of our samples exceeded the SSL for Hg. Because of the serious health effects that can result from over-exposure to heavy metals, the information obtained in this study should be used to influence our future dietary and recreational habits.

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

USDA-ARS?s Scientific Manuscript database

The Grand Bay National Estuarine Research Reserve has the highest biotic diversity of habitats and offer a reserve of food resources and commercially significant species. Rapid human civilization has led to accumulation of heavy metals and trace elements in estuaries. The Grand Bay National Estuarin...

Reduction of heavy metal from soil in Bakri Landfill, Muar, Johor by using Electrokinetic method

NASA Astrophysics Data System (ADS)

Azhar, ATS; Muhammad, E.; Zaidi, E.; Ezree, AM; Aziman, M.; Hazreek, ZAM; Nizam, ZM; Norshuhaila, MS

2017-08-01

The present study focuses on the contamination levels and distribution of heavy metals in soil samples located at Bakri Landfill area, Muar, Johor, Malaysia. The aim of this study is to determine the type of heavy metal elements that contribute towards soil contamination and to reduce them based on the comparison of elemental analysis between pre and post Electrokinetic (EK) processes. The ppm level concentration of elements in this landfill soil is measured by using X-ray Fluorescence analysis. ICP-MS testing was carried out for liquid samples analysis. There were two set of EK experiments conducted. In first phase, voltage was maintained at 3 Vcm-1 and prolonged for 3 hours, while second phase was operated at 1 Vcm-1 for 48 hours. In this work, distilled water was used as an electrolyte for the process and two identical copper foil were used as electrodes due to high electrical conductivity. The application of EK remediation revealed that successful removal of Rb and Ba elements in the soil were observed by 2-3%, however other heavy metals have not changed.

Fast elemental screening of soil and sediment profiles using small-spot energy-dispersive X-ray fluorescence: application to mining sediments geochemistry.

PubMed

Gonzalez-Fernandez, Oscar; Queralt, Ignacio

2010-09-01

Elemental analysis of different sediment cores originating from the Cartagena-La Union mining district in Spain was carried out by means of a programmable small-spot energy-dispersive X-ray fluorescence (EDXRF) spectrometer to study the distribution of heavy metals along soil profiles. Cores were obtained from upstream sediments of a mining creek, from the lowland sedimentation plain, and from a mining landfill dump (tailings pile). A programmable two-dimensional (2D) stage and a focal spot resolution of 600 μm allow us to obtain complete core mapping. Geochemical results were verified using a more powerful wavelength-dispersion X-ray fluorescence (WDXRF) technique. The data obtained was processed in order to study the statistical correlations within the elemental compositions. The results obtained allow us to observe the differential in-depth distribution of heavy metals among the sampled zones. Dump site cores exhibit a homogeneous distribution of heavy metals, whereas the alluvial plain core shows accumulation of heavy metals in the upper part. This approach can be useful for the fast screening of heavy metals in depositional environments around mining sites.

Morphological re-description of Electrotaenia malapteruri (Cestoda: Proteocephalidae) and Dujardinnascaris malapteruri (Nematoda: Heterocheilidae) infecting the Electric catfish Malapterurus electricus and heavy metal accumulation in host and parasites in relation to water and sediment analysis in Lake Manzala, North Delta, Egypt.

PubMed

Abdel-Gaber, Rewaida; Abdel-Ghaffar, Fathy; Abdallah Shazly, Mohamed; Morsy, Kareem; Al Quraishy, Saleh; Mohamed, Sanna; Mehlhorn, Heinz

2017-06-01

Parasites are one of the most serious limiting factors in aquaculture. The Electric catfish Malapterurus electricus was subjected to study the prevalence and mean intensity of parasitic infections throughout the whole year of 2015. Heavy metals accumulation in host fish and parasites were determined in relation to water quality and sediments of two different sites of Lake Manzala (Manzala and Bahr El-Baqar), Egypt. A total of 100 specimens of Electric catfish were collected and examined for the presence of helminth parasites. Two parasite species were recovered and morphologically identified. These were cestoda Electrotaenia malapteruri and nematode Dujardinnascaris malapteruri. Heavy metal analysis in water and sediments showed that measured heavy metals in Bahr El-Baqar were found in risky levels higher than permissible limits and Manzala site. Sediments were found to contain a higher level of metals than water samples. Heavy metals accumulation in recovered parasites and their host were also determined and showed significantly higher concentrations in parasites compared to their host tissues. According to bioconcentration factors, E. malapteruri showed that highest accumulation rate for all recorded elements up to 302. Essential elements like Cu and Fe were found in significantly higher concentrations in D. malapteruri, whereas E. malapteruri accumulated elements Cd, Pb, Ni, Mn, Zn and Ca to a significantly higher degree. Accordingly, the ratios (C[D.malapteruri]/C[E. malapteruri]) for most essential elements were higher than 0.5. Therefore, fish cestodes can be regarded as useful bio-indicators more than nematodes when evaluating the environmental pollution of aquatic ecosystems by heavy metals.

[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.

A critical review of the bioavailability and impacts of heavy metals in municipal solid waste composts compared to sewage sludge.

PubMed

Smith, Stephen R

2009-01-01

The content, behaviour and significance of heavy metals in composted waste materials is important from two potentially conflicting aspects of environmental legislation in terms of: (a) defining end-of-waste criteria and increasing recycling of composted residuals on land and (b) protecting soil quality by preventing contamination. This review examines the effects of heavy metals in compost and amended soil as a basis for achieving a practical and sustainable balance between these different policy objectives, with particular emphasis on agricultural application. All types of municipal solid waste (MSW) compost contain more heavy metals than the background concentrations present in soil and will increase their contents in amended soil. Total concentrations of heavy metals in source-segregated and greenwaste compost are typically below UK PAS100 limits and mechanical segregated material can also comply with the metal limits in UK PAS100, although this is likely to be more challenging. Zinc and Pb are numerically the elements present in the largest amounts in MSW-compost. Lead is the most limiting element to use of mechanically-segregated compost in domestic gardens, but concentrations are typically below risk-based thresholds that protect human health. Composted residuals derived from MSW and greenwaste have a high affinity for binding heavy metals. There is general consensus in the scientific literature that aerobic composting processes increase the complexation of heavy metals in organic waste residuals, and that metals are strongly bound to the compost matrix and organic matter, limiting their solubility and potential bioavailability in soil. Lead is the most strongly bound element and Ni the weakest, with Zn, Cu and Cd showing intermediate sorption characteristics. The strong metal sorption properties of compost produced from MSW or sewage sludge have important benefits for the remediation of metal contaminated industrial and urban soils. Compost and sewage sludge additions to agricultural and other soils, with background concentrations of heavy metals, raise the soil content and the availability of heavy metals for transfer into crop plants. The availability in soil depends on the nature of the chemical association between a metal with the organic residual and soil matrix, the pH value of the soil, the concentration of the element in the compost and the soil, and the ability of the plant to regulate the uptake of a particular element. There is no evidence of increased metal release into available forms as organic matter degrades in soil once compost applications have ceased. However, there is good experimental evidence demonstrating the reduced bioavailability and crop uptake of metals from composted biosolids compared to other types of sewage sludge. It may therefore be inferred that composting processes overall are likely to contribute to lowering the availability of metals in amended soil compared to other waste biostabilisation techniques. The total metal concentration in compost is important in controlling crop uptake of labile elements, like Zn and Cu, which increases with increasing total content of these elements in compost. Therefore, low metal materials, which include source-segregated and greenwaste composts, are likely to have inherently lower metal availabilities overall, at equivalent metal loading rates to soil, compared to composted residuals with larger metal contents. This is explained because the compost matrix modulates metal availability and materials low in metals have stronger sorption capacity compared to high metal composts. Zinc is the element in sewage sludge-treated agricultural soil identified as the main concern in relation to potential impacts on soil microbial activity and is also the most significant metal in compost with regard to soil fertility and microbial processes. However, with the exception of one study, there is no other tangible evidence demonstrating negative impacts of heavy metals applied to soil in compost on soil microbial processes and only positive effects of compost application on the microbial status and fertility of soil are reported. The negative impacts on soil microorganisms apparent in one long-term field experiment could be explained by the exceptionally high concentrations of Cd and other elements in the applied compost, and of Cd in the compost-amended soil, which are unrepresentative of current practice and compost quality. The metal contents of source-segregated MSW or greenwaste compost are smaller compared to mechanically-sorted MSW-compost and sewage sludge, and low metal materials also have the smallest potential metal availabilities. Composting processes also inherently reduce metal availability compared to other organic waste stabilisation methods. Therefore, risks to the environment, human health, crop quality and yield, and soil fertility, from heavy metals in source-segregated MSW or greenwaste-compost are minimal. Furthermore, composts produced from mechanically-segregated MSW generally contain fewer metals than sewage sludge used as an agricultural soil improver under controlled conditions. Consequently, the metal content of mechanically-segregated MSW-compost does not represent a barrier to end-use of the product. The application of appropriate preprocessing and refinement technologies is recommended to minimise the contamination of mechanically-segregated MSW-compost as far as practicable. In conclusion, the scientific evidence indicates that conservative, but pragmatic limits on heavy metals in compost may be set to encourage recycling of composted residuals and contaminant reduction measures, which at the same time, also protect the soil and environment from potentially negative impacts caused by long-term accumulation of heavy metals in soil.

Sustainable sources of biomass for bioremediation of heavy metals in waste water derived from coal-fired power generation.

PubMed

Saunders, Richard J; Paul, Nicholas A; Hu, Yi; de Nys, Rocky

2012-01-01

Biosorption of heavy metals using dried algal biomass has been extensively described but rarely implemented. We contend this is because available algal biomass is a valuable product with a ready market. Therefore, we considered an alternative and practical approach to algal bioremediation in which algae were cultured directly in the waste water stream. We cultured three species of algae with and without nutrient addition in water that was contaminated with heavy metals from an Ash Dam associated with coal-fired power generation and tested metal uptake and bioremediation potential. All species achieved high concentrations of heavy metals (to 8% dry mass). Two key elements, V and As, reached concentrations in the biomass of 1543 mg.kg(-1) DW and 137 mg.kg(-1) DW. Growth rates were reduced by more than half in neat Ash Dam water than when nutrients were supplied in excess. Growth rate and bioconcentration were positively correlated for most elements, but some elements (e.g. Cd, Zn) were concentrated more when growth rates were lower, indicating the potential to tailor bioremediation depending on the pollutant. The cosmopolitan nature of the macroalgae studied, and their ability to grow and concentrate a suite of heavy metals from industrial wastes, highlights a clear benefit in the practical application of waste water bioremediation.

High levels of heavy metal accumulation in dental calculus of smokers: a pilot inductively coupled plasma mass spectrometry study.

PubMed

Yaprak, E; Yolcubal, I; Sinanoğlu, A; Doğrul-Demiray, A; Guzeldemir-Akcakanat, E; Marakoğlu, I

2017-02-01

Various trace elements, including toxic heavy metals, may exist in dental calculus. However, the effect of environmental factors on heavy metal composition of dental calculus is unknown. Smoking is a major environmental source for chronic toxic heavy metal exposition. The aim of this study is to compare toxic heavy metal accumulation levels in supragingival dental calculus of smokers and non-smokers. A total of 29 supragingival dental calculus samples were obtained from non-smoker (n = 14) and smoker (n = 15) individuals. Subjects with a probability of occupational exposure were excluded from the study. Samples were analyzed by inductively coupled plasma mass spectrometry in terms of 26 metals and metalloids, including toxic heavy metals. Toxic heavy metals, arsenic (p < 0.05), cadmium (p < 0.05), lead (p < 0.01), manganese (p < 0.01) and vanadium (p < 0.01) levels were significantly higher in smokers than non-smokers. The levels of other examined elements were similar in both groups (p > 0.05). Within the limitations of this study, it can be concluded that the elementary composition of dental calculus may be affected by environmental factors such as tobacco smoke. Therefore, dental calculus may be utilized as a non-invasive diagnostic biological material for monitoring chronic oral heavy metal exposition. However, further studies are required to evaluate its diagnostic potential. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Spatio-temporal distribution and environmental risk of sedimentary heavy metals in the Yangtze River Estuary and its adjacent areas.

PubMed

Chen, Bin; Liu, Jian; Qiu, Jiandong; Zhang, Xilin; Wang, Shuang; Liu, Jinqing

2017-03-15

Twenty-five surface sediments and one sediment core sample were collected from the study area. Grain size, major elements, and heavy metals were determined. The content of fine-grained sediments (silt and clay), as well as the concentrations of major elements and heavy metals, showed seaward decreasing trends, with high content in the coastal areas of the East China Sea (ECS) and south west of Jeju Island. Low enrichment factor (EF) and geoaccumulation index (Igeo) values were found, indicating that the ecological risk of heavy metals was low. The EF values obtained from the high-resolution sedimentary records of heavy metals in the Yangtze River Estuary could be divided into Stage 1 (1950s to the late 1970s) and Stage 2 (late 1970s to the current sampling day), which coincided with economic development of the Yangtze River Basin, implementation of environmental protection, and impoundment of the Three Gorges Dam. Copyright © 2016. Published by Elsevier Ltd.

Characterisation of heavy metal-bearing phases in stream sediments of the Meža River Valley, Slovenia, by means of SEM/EDS analysis

NASA Astrophysics Data System (ADS)

Miler, M.; Gosar, M.

2010-02-01

Stream sediment reflects the rock structure of the catchment area, its geochemical characteristics and possible recent contamination upstream of the sampling point and thus, it is most frequently used in geochemical researches of heavy metal pollution. Stream sediment samples were collected along the Meža River and its tributaries and the Drava River, located in the NNE part of Slovenia. Previous geochemical studies have shown that these sediments are heavily polluted with heavy metals as a consequence of past mining of Pb-Zn ore and steelworks activities. Conventional geochemical analyses (ICP-MS, AAS, etc.) provided limited information on mineralogy, morphology and sources of heavy metal-bearing phases therefore SEM/EDS was utilized. Several problems were confronted with during EDS analysis, which are related to identification and quantification of light elements, identification of elements due to peak overlaps and quantification of spectra from unpolished samples. These problems were successfully dealt with. SEM/EDS enabled successful identification of heavy metal-bearing phases in stream sediments. Ore mineral phases, such as cerussite, sphalerite, smithsonite and galena, different heavy metal-bearing Fe-alloys, Fe-oxides and spherical particles and common rock-forming and accessory mineral phases, such as barite, rutile, ilmenite, zircon and monazite, were identified using solely SEM/EDS. These results were used for subsequent geochemical interpretation and source apportionment of heavy metals, according to associations of different heavy metal-bearing phases. Heavy metal-bearing phases were arranged by their source and genesis into three groups, denoted as geogenic/technogenic, technogenic and geogenic.

A large-scale field trial experiment to derive effective release of heavy metals from incineration bottom ashes during construction in land reclamation.

PubMed

Chan, Wei-Ping; Ren, Fei; Dou, Xiaomin; Yin, Ke; Chang, Victor Wei-Chung

2018-05-08

Recycling of incineration bottom ashes (IBA) is attracting great interest as it is considered as a vital aspect for closing the waste loop to achieve sustainable development at the growing cities around the world. Various laboratory-testing methods are developed to assess the release potential of heavy metals - one of the most important concerns of using IBA, by reflecting the release conditions of heavy metals from IBA based on the targeted land reclamation application scenarios and corresponding environmental conditions. However, realistic release of the concerned elements in actual application with the presence of complex environment could possibly deviate from the outcomes produced by leaching tests carried out in the laboratory. Hence, a set of large-scale column trial experiments was performed to experimentally determine the effective release of heavy metals, when IBA is used as a filling material in land reclamation. 20 tons of IBA and 320 m 3 of seawater were used in six column trial experiments. The release of 13 heavy metal elements was analyzed through multiple aspects which included kinetics of release, distribution of elements in seawater and the impacts of two different dumping methods, with and without application of a chute. After dumping of IBA into the seawater, almost instantaneous release of heavy metals with uniform horizontal dispersion was observed. Higher concentration of these elements was observed near the bottom of the column, especially when a chute was applied. Comparative analysis was then carried out to establish relationships between the results obtained from the column trial with batch leaching test carried out in the laboratory. Distinctive relationships were observed for different heavy metals which suggests the need of pursuance of further understanding on leaching of IBA in real application scenario and complex environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Geochemical cartography as a tool for assessing the degree of soil contamination with heavy metals in Poland

NASA Astrophysics Data System (ADS)

Szymon Borkowski, Andrzej; Kwiatkowska-Malina, Jolanta

2016-04-01

Spatial disposition of chemical elements including heavy metals in the soil environment is a very important information during preparation of the thematic maps for the environmental protection and/or spatial planning. This knowledge is also essential for the earth's surface and soil's monitoring, designation of areas requiring improvement including remediation. The main source of anthropogenic pollution of soil with heavy metals are industry related to the mining coal and liquid fuels, mining and metallurgy, chemical industry, energy production, waste management, agriculture and transport. The geochemical maps as a kind of specific thematic maps made on the basis of datasets obtained from the Polish Geological Institute's resources allow to get to know the spatial distribution of different chemical elements including heavy metals in soil. The results of the research carried out by the Polish Geological Institute showed strong contamination in some regions in Poland mainly with arsenic, cadmium, lead and nickel. For this reason it was the point to prepare geochemical maps showing contamination of soil with heavy metals, and determine main sources of contamination and zones where heavy metals concentration was higher than acceptable contents. It was also presented a summary map of soil contamination with heavy metals. Additionally, location of highly contaminated zones was compiled with predominant in those areas types of arable soils and then results were thoroughly analyzed. This information can provide a base for further detailed studies on the soil contamination with heavy metals.

The Heavy Metals in Agrosystems and Impact on Health and Quality of Life.

PubMed

Tutic, Adnan; Novakovic, Srecko; Lutovac, Mitar; Biocanin, Rade; Ketin, Sonja; Omerovic, Nusret

2015-06-15

The metal is a chemical element that conducts electricity well and heat, and the nonferrous metals builds cations and ionic bonds. Heavy metals include metals whose density is higher than 5 g/cm(3). The whole range of the metal is in the form of essential trace elements, essential for a number of functions in the human body, and its deficiency results in a lack of occurrence of a serious symptom. The best examples are anemia lack of iron, lack of chromium in diabetes, growth problems in lack of nickel. Other elements such as lead, cadmium, mercury, arsenic and molybdenum have been shown to exhibit large quantities of toxic effects. The paper examines the problem of heavy metals originating from agriculture on agroecosystems. This group of pollutants is considered the most important cause of degradation of soil quality, surface and groundwater and direct causal adverse effects on human and animal health. In order to complete the environmental monitoring of pollutants, these main categories, origins, and possible negative impacts of the basic principles of preventing their toxic effects were examined.

The Heavy Metals in Agrosystems and Impact on Health and Quality of Life

PubMed Central

Tutic, Adnan; Novakovic, Srecko; Lutovac, Mitar; Biocanin, Rade; Ketin, Sonja; Omerovic, Nusret

2015-01-01

The metal is a chemical element that conducts electricity well and heat, and the nonferrous metals builds cations and ionic bonds. Heavy metals include metals whose density is higher than 5 g/cm3. The whole range of the metal is in the form of essential trace elements, essential for a number of functions in the human body, and its deficiency results in a lack of occurrence of a serious symptom. The best examples are anemia lack of iron, lack of chromium in diabetes, growth problems in lack of nickel. Other elements such as lead, cadmium, mercury, arsenic and molybdenum have been shown to exhibit large quantities of toxic effects. The paper examines the problem of heavy metals originating from agriculture on agroecosystems. This group of pollutants is considered the most important cause of degradation of soil quality, surface and groundwater and direct causal adverse effects on human and animal health. In order to complete the environmental monitoring of pollutants, these main categories, origins, and possible negative impacts of the basic principles of preventing their toxic effects were examined. PMID:27275249

Fate and transport of heavy metals and radioelements in groundwater aquifers of Al-Qunfudhah and Wadi Haliy quadrangles, southwest of Saudi Arabia

NASA Astrophysics Data System (ADS)

Bajabaa, S. A.; Abd El-Naby, H.; Dawood, Y.

2009-12-01

The fate and transport of heavy metals and radioelements in groundwater aquifers in five wadis located in the Al Qunfudhah and Wadi Haliy quadrangles were investigated. These wadis are an important source of water to the Red Sea coastal plain. Copper, zinc and other base-metals mineralization occur at eastern parts of these quadrangles that dominates the water catchments area of these wadis. Water, rock and soil samples were collected from all wadis and they were analyzed for major, trace elements, heavy metals and stable isotopes. The chemical and isotopic results showed active water/rock interaction. The preliminary investigation of the data analyses showed some samples with high heavy metals and uranium contents. Generally, the uranium and heavy metal contents are higher in samples collected from the upstream area of each wadi where the crystalline rocks are exposed and direct contact with the runoff. The uranium contents were as high as 120 ppb in some water samples. These elevated values are mainly due to two factors water rock interaction and concentration through evaporation. It was also observed to have elevated heavy metal contents near mining activates, which suggests that these mining activates are playing an important role in mobilizing the heavy elements and in turn affecting the water quality in these wadis.

A city scale study on the effects of intensive groundwater heat pump systems on heavy metal contents in groundwater.

PubMed

García-Gil, Alejandro; Epting, Jannis; Garrido, Eduardo; Vázquez-Suñé, Enric; Lázaro, Jesús Mateo; Sánchez Navarro, José Ángel; Huggenberger, P; Calvo, Miguel Ángel Marazuela

2016-12-01

As a result of the increasing use of shallow geothermal resources, hydraulic, thermal and chemical impacts affecting groundwater quality can be observed with ever increasing frequency (Possemiers et al., 2014). To overcome the uncertainty associated with chemical impacts, a city scale study on the effects of intensive geothermal resource use by groundwater heat pump systems on groundwater quality, with special emphasis on heavy metal contents was performed. Statistical analysis of geochemical data obtained from several field campaigns has allowed studying the spatiotemporal relationship between temperature anomalies in the aquifer and trace element composition of groundwater. The relationship between temperature and the concentrations of trace elements resulted in weak correlations, indicating that temperature changes are not the driving factor in enhancing heavy metal contaminations. Regression models established for these correlations showed a very low reactivity or response of heavy metal contents to temperature changes. The change rates of heavy metal contents with respect to temperature changes obtained indicate a low risk of exceeding quality threshold values by means of the exploitation regimes used, neither producing nor enhancing contamination significantly. However, modification of pH, redox potential, electrical conductivity, dissolved oxygen and alkalinity correlated with the concentrations of heavy metals. In this case, the change rates of heavy metal contents are higher, with a greater risk of exceeding threshold values. Copyright © 2016 Elsevier B.V. All rights reserved.

Sustainable Sources of Biomass for Bioremediation of Heavy Metals in Waste Water Derived from Coal-Fired Power Generation

PubMed Central

Saunders, Richard J.; Paul, Nicholas A.; Hu, Yi; de Nys, Rocky

2012-01-01

Biosorption of heavy metals using dried algal biomass has been extensively described but rarely implemented. We contend this is because available algal biomass is a valuable product with a ready market. Therefore, we considered an alternative and practical approach to algal bioremediation in which algae were cultured directly in the waste water stream. We cultured three species of algae with and without nutrient addition in water that was contaminated with heavy metals from an Ash Dam associated with coal-fired power generation and tested metal uptake and bioremediation potential. All species achieved high concentrations of heavy metals (to 8% dry mass). Two key elements, V and As, reached concentrations in the biomass of 1543 mg.kg−1 DW and 137 mg.kg−1 DW. Growth rates were reduced by more than half in neat Ash Dam water than when nutrients were supplied in excess. Growth rate and bioconcentration were positively correlated for most elements, but some elements (e.g. Cd, Zn) were concentrated more when growth rates were lower, indicating the potential to tailor bioremediation depending on the pollutant. The cosmopolitan nature of the macroalgae studied, and their ability to grow and concentrate a suite of heavy metals from industrial wastes, highlights a clear benefit in the practical application of waste water bioremediation. PMID:22590550

Distributing Characteristics of Heavy Metal Elements in A Tributary of Zhedong River in Laowangzhai Gold Deposit, Yunnan (China): An Implication to Environmentology from Sediments

NASA Astrophysics Data System (ADS)

Yang, Shuran; Danĕk, Tomáš; Yang, Xiaofeng; Cheng, Xianfeng

2016-10-01

Five heavy metal contents from five sediments and seven sediment profiles in an upstream reach of Zhedong river in Laowangzhai gold deposit were investigated in this research, along with analysis of the horizontal distribution, the surface distribution, the vertical distribution and the interlayer distribution of five heavy metal contents: arsenic (As), mercury (Hg), copper (Cu), lead (Pb) and zinc (Zn). The potential ecological risk of five heavy metals was evaluated to help understanding pollution control of Laowangzhai deposit.

[Determination of heavy metals in four traditional Chinese medicines by ICP-MS].

PubMed

Wen, Hui-Min; Chen, Xiao-Hui; Dong, Ting-Xia; Zhan, Hua-Qiang; Bi, Kai-Shun

2006-08-01

To establish a ICP-MS method for the determination of heavy metals, including As, Hg, Pb, Cd, in four traditional Chinese medicines. The samples were digested by closed-versel microwave. The four heavy metals were directly analyzed by ICP-MS. Select internal standard element in for the method by which the analyse signal drife is corrected by the signal of another element (internal standard elements) added to both the standard solution and sample. For all of the analyzed heary methals, the correlative coefficient of the calibration curves was over 0.999 2. The recovery rates of the procedure were 97.5%-108.0%, and its RSD was lower than 11.6%. This method was convenient, quick-acquired, accurate and highly sensitive. The method can be used for the quality control of trace elements in traditional Chinese medicines and for the contents determination of traditional Chinese medicines from different habitats and species.

[MONITORING OF THE CONTENT OF HEAVY METALS AND ELEMENTS IN THE SNOW COVER IN AGRICULTURAL SOILS AT THE TERRITORY OF THE MOSCOW REGION].

PubMed

Ermakov, A A; Karpova, E A; Malysheva, A G; Mikhaylova, R I; Ryzhova, I N

2015-01-01

The monitoring of snow cover pollution by heavy metals and elements (zinc, copper, lead, cadmium, arsenic, nickel, chromium, strontium, manganese, fluorine, lithium) was performed in 20 districts of the Moscow region in 2009, 2012 and 2013. The assessment of the levels of contamination by heavy metals and elements was given by means of comparison of them with the average values in the snow cover near Moscow in the end of the last century and in some areas of the world, that no exposed to technological environmental impact. 7 districts of Moscow region were characterized by a high content of lead and cadmium in the snow water. It requires the control of water, soil and agricultural products pollution.

Structural and elemental analysis of bottom sediments from the Paraíba do Sul River (SE, Brazil) by analytical microscopy

NASA Astrophysics Data System (ADS)

Miguens, Flávio Costa; Oliveira, Martha Lima de; Ferreira, Amanda de Oliveira; Barbosa, Laís Rodrigues; Melo, Edésio José Tenório de; Carvalho, Carlos Eduardo Veiga de

2016-03-01

The Paraíba do Sul River (PSR) is a medium-sized river that flows through the Minas Gerais, São Paulo and Rio de Janeiro Brazilian states the three most developed states in Brazil. Industrial parks and cities have historically been established along the river basin. The waters of PSR are used in agriculture, industry and human consumption of over 20 million people, including Rio de Janeiro City. Furthermore, the river receives effluent from these activities: agricultural runoff, industrial waste, and domestic sewage. Therefore, PSR has been considered polluted, particularly by heavy metals. In order to assess heavy metals in bottom sediments grains of the PSR, to infer their elemental composition, and to characterize individual sediment grains morphology, a non-destructive methodology - X-ray microanalyses (Scanning Electron Microscope coupled to Energy Dispersive X-rays Spectrometer/SEM/EDS) - was used. Heavy metals - Cr, Mn, Ni, Cu, Zn, Zr, Ag, Ba, Au, La, Ce, Nd, Th, Y, Sn, Os and Pb - were detected by SEM/EDS in bottom sediment grains from PSR, predominantly in grains with equivalent diameter ≤10 μm. They occurred as silicates, oxides (hydro-oxides), sulfides, carbonates, sulfates, phosphates and chlorides. All detected heavy metals occurred as, at least, one kind of soluble metal compound, mainly due to ionic exchange from silicates, with the exception of Ag, which was chloride, sulfate or metallic as Os, Au and Pb. These results corroborate heavy metal PSR pollution and food chain risk, considering that near-shore continental shelf is free of heavy metals contamination. Our results also give support to the hypothesis that the PSR estuary can act as a trap for these elements.

Heavy Metals in the Environment-Historical Trends

NASA Astrophysics Data System (ADS)

Callender, E.

2003-12-01

These six metals, commonly classified as heavy metals, are a subset of a larger group of trace elements that occur in low concentration in the Earth's crust. These heavy metals were mined extensively for use in the twentieth century Industrial Society. Nriagu (1988a) estimated that between 0.5 (Cd) and 310 (Cu) million metric tons of these metals were mined and ultimately deposited in the biosphere. In many instances, the inputs of these metals from anthropogenic sources exceed the contributions from natural sources (weathering, volcanic eruptions, forest fires) by several times ( Adriano, 1986). In this chapter, heavy metals (elements having densities greater than 5) and trace elements (elements present in the lithosphere in concentrations less than 0.1%) are considered synonymous.It has been observed in the past that the rate of emission of these trace metals into the atmosphere is low due to their low volatility. However, with the advent of large-scale metal mining and smelting as well as fossil-fuel combustion in the twentieth century, the emission rate of these metals has increased dramatically. As most of these emissions are released into the atmosphere where the mammals live and breathe, we see a great increase in the occurrence of health problems such as lead (Pb) poisoning, cadmium (Cd) Itai-itai disease, chromium (Cr), and nickel (Ni) carcinogenesis.In this chapter, the author has attempted to present a synopsis of the importance of these metals in the hydrocycle, their natural and anthropogenic emissions into the environment, their prevalent geochemical form incorporated into lacustrine sediments, and their time-trend distributions in watersheds that have been impacted by urbanization, mining and smelting, and other anthropogenic activities. These time trends are reconstructed from major-minor-trace-element distributions in age-dated sediment cores, mainly from reservoirs where the mass sedimentation rates (MSRs) are orders of magnitude greater than those in natural lakes, the consequences of which tend to preserve the heavy-metal signatures and minimize the metal diagenesis (Callender, 2000). This chapter focuses mainly on the heavy metals in the terrestrial and freshwater environments whilst the environmental chemistry of trace metals in the marine environment is discussed in Volume 6, Chapter 3 of the Treatise on Geochemistry.The data presented in Table 2, Table 3, Table 4 and Table 5 are updated as much as possible, with many of the references postdate the late 1980s. Notable exceptions are riverine particulate matter chemistry ( Table 2), some references in Table 3, and references concerning the geochemical properties of the six heavy metals discussed in this chapter. There appears to be no recent publication that updates the worldwide average for riverine particulate matter trace metal chemistry ( Martin and Whitfield, 1981; Martin and Windom, 1991). This is supported by the fact that two recent references ( Li, 2000; Chester, 2000) concerning marine chemistry still refer to this 1981 publication. As for references in Table 3, there is a very limited data available concerning the pathways of heavy-metal transport to lakes. Some of the important works have been considered and reviewed in this chapter. In addition, the analytical chemistry of the sedimentary materials has changed little over the past 30 years until the advent and use of inductively coupled plasma/mass spectrometry (ICP/MS) in the late 1990s. Extensive works concerning the geochemical properties of heavy metals have been published during the past 40 years and to the author's knowledge these have survived the test of time.

Heavy metal contents in the sediments of astatic ponds: Influence of geomorphology, hydroperiod, water chemistry and vegetation.

PubMed

Gołdyn, Bartłomiej; Chudzińska, Maria; Barałkiewicz, Danuta; Celewicz-Gołdyn, Sofia

2015-08-01

The contents of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were analysed in the bottom sediments of 30 small, astatic ponds located in the agricultural landscape of Western Poland. The samples were collected from 118 stations located in patches of four vegetation types. Relationships between the contents of particular elements and four groups of factors (geomorphology, hydroperiod, water quality and vegetation) were tested using Redundancy Analysis (RDA). The most important factors influencing the heavy metal contents were the maximum depth and area of the pond, its hydroperiod, water pH and conductivity values. In general, low quantities of heavy metals were recorded in the sediments of kettle-like ponds (small but located in deep depressions) and high in water bodies of the shore-bursting type (large but shallow). Moreover, quantities of particular elements were influenced by the structure of the vegetation covering the pond. Based on the results, we show which types of astatic ponds are most exposed to contamination and suggest some conservation practices that may reduce the influx of heavy metals. Copyright © 2015 Elsevier Inc. All rights reserved.

Oligopeptide-heavy metal interaction monitoring by hybrid gold nanoparticle based assay.

PubMed

Politi, Jane; Spadavecchia, Jolanda; Iodice, Mario; de Stefano, Luca

2015-01-07

Phytochelatins are small peptides that can be found in several organisms, which use these oligopeptides to handle heavy metal elements. Here, we report a method for monitoring interactions between lead(ii) ions in aqueous solutions and phytochelatin 6 oligopeptide bioconjugated onto pegylated gold nanorods (PEG-AuNrs). This study is the first step towards a high sensitive label free optical biosensor to quantify heavy metal pollution in water.

Distribution, sources, and fluxes of heavy metals in the Pearl River Delta, South China.

PubMed

Geng, Junjie; Wang, Yiping; Luo, Hanjin

2015-12-30

Riverine samples were collected at various locations in the Pearl River Delta (PRD) to determine the concentrations of heavy metals (Cr, Ni, Cu, Mn, Zn, Cd, and Pb) in time and space and to estimate the fluxes of heavy metals to the coastal waters off South China. Most of the elements exhibit clear temporal and spatial trends. Principal component analysis shows that surface erosion is the major factor affecting metal concentrations in particulates in the PRD. Natural geology is an important source of these heavy metals. The annual fluxes of Cr, Ni, Cu, Mn, Zn, Cd, and Pb in upstream and downstream were 445, 256, 241, 3293, 1279, 12, and 317 t/year and 1823, 1144, 1786, 15,634, 6183, 74, and 2017 t/year, respectively. A comparison indicated that the annual fluxes of Mn accounted for 1.3% of the global river fluxes, whereas other elements contribute <1%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Does heavy metal exposure affect the condition of Whitethroat (Sylvia communis) nestlings?

PubMed

Turzańska-Pietras, Katarzyna; Chachulska, Justyna; Polechońska, Ludmiła; Borowiec, Marta

2018-03-01

Anthropogenic pollution results in high concentrations of heavy metals in the environment. Due to their persistence and a high potential for bioaccumulation, metals are a real threat for birds breeding in industrial areas. The aim of the present study has been to explore the contents of heavy metals (arsenic As, cadmium Cd, chromium Cr, copper Cu, iron Fe, nickel Ni, lead Pb and zinc Zn) in the excreta of Whitethroat (Sylvia communis) nestlings living in polluted environment and to investigate the relationship between these contents and the nestlings' condition. Excrement samples contained all the studied elements. The contents of arsenic, cadmium, copper and zinc in the excreta of nestlings from nests located close to a slag dump were several times higher than in the soil near the dump, which suggested accumulation in food consumed by the birds. Condition parameters (body mass and haemoglobin concentration) were not related to heavy metal concentrations in the nestlings' excreta, except of Zn. It is possible that Whitethroats are able to detoxicate heavy metals to a certain extent. Detailed, multi-element analysis of the environment, food and bird tissues or excreta should be performed to explore relations between different chemicals and bird condition.

Concentration distribution and assessment of several heavy metals in sediments of west-four Pearl River Estuary

NASA Astrophysics Data System (ADS)

Wang, Shanshan; Cao, Zhimin; Lan, Dongzhao; Zheng, Zhichang; Li, Guihai

2008-09-01

Grain size parameters, trace metals (Co, Cu, Ni, Pb, Cr, Zn, Ba, Zr and Sr) and total organic matter (TOM) of 38 surficial sediments and a sediment core of west-four Pearl River Estuary region were analyzed. The spacial distribution and the transportation procession of the chemical element in surficial sediments were studied mainly. Multivariate statistics are used to analyses the interrelationship of metal elements, TOM and the grain size parameters. The results demonstrated that terrigenous sediment taken by the rivers are main sources of the trace metal elements and TOM, and the lithology of parent material is a dominating factor controlling the trace metal composition in the surficial sediment. In addition, the hydrodynamic condition and landform are the dominating factors controlling the large-scale distribution, while the anthropogenic input in the coastal area alters the regional distribution of heavy metal elements Co, Cu, Ni, Pb, Cr and Zn. The enrichment factor (EF) analysis was used for the differentiation of the metal source between anthropogenic and naturally occurring, and for the assessment of the anthropogenic influence, the deeper layer content of heavy metals were calculated as the background values and Zr was chosen as the reference element for Co, Cu, Ni, Pb, Cr and Zn. The result indicate prevalent enrichment of Co, Cu, Ni, Pb and Cr, and the contamination of Pb is most obvious, further more, the peculiar high EF value sites of Zn and Pb probably suggest point source input.

Neutron-capture Nucleosynthesis in the First Stars

NASA Astrophysics Data System (ADS)

Roederer, Ian U.; Preston, George W.; Thompson, Ian B.; Shectman, Stephen A.; Sneden, Christopher

2014-04-01

Recent studies suggest that metal-poor stars enhanced in carbon but containing low levels of neutron-capture elements may have been among the first to incorporate the nucleosynthesis products of the first generation of stars. We have observed 16 stars with enhanced carbon or nitrogen using the MIKE Spectrograph on the Magellan Telescopes at Las Campanas Observatory and the Tull Spectrograph on the Smith Telescope at McDonald Observatory. We present radial velocities, stellar parameters, and detailed abundance patterns for these stars. Strontium, yttrium, zirconium, barium, europium, ytterbium, and other heavy elements are detected. In four stars, these heavy elements appear to have originated in some form of r-process nucleosynthesis. In one star, a partial s-process origin is possible. The origin of the heavy elements in the rest of the sample cannot be determined unambiguously. The presence of elements heavier than the iron group offers further evidence that zero-metallicity rapidly rotating massive stars and pair instability supernovae did not contribute substantial amounts of neutron-capture elements to the regions where the stars in our sample formed. If the carbon- or nitrogen-enhanced metal-poor stars with low levels of neutron-capture elements were enriched by products of zero-metallicity supernovae only, then the presence of these heavy elements indicates that at least one form of neutron-capture reaction operated in some of the first stars. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile, and The McDonald Observatory of The University of Texas at Austin.

Comparison of single extraction procedures and the application of an index for the assessment of heavy metal bioavailability in river sediments.

PubMed

Sakan, Sanja; Popović, Aleksandar; Škrivanj, Sandra; Sakan, Nenad; Đorđević, Dragana

2016-11-01

Metals in sediments are present in different chemical forms which affect their ability to transfer. The objective of this body of work was to compare different extraction methods for the bioavailability evaluation of some elements, such as Ba, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, V and Zn from Serbian river sediments. A bioavailability risk assessment index (BRAI) was used for the quantification of heavy metal bioavailability in the sediments. Actual and potential element availability was assessed by single extractions with mild (CaCl 2 and CH 3 COONH 4 ) and acidic (CH 3 COOH) extractants and complexing agents (EDTA). Aqua regia extraction was used for the determination of the pseudo-total element content in river sediments. In different single extraction tests, higher extraction of Cd, Cu, Zn and Pb was observed than for the other elements. The results of the single extraction tests revealed that there is a considerable chance of metal leaching from the sediments assessed in this study. When the BRAI was applied, the results showed a high risk of heavy metal bioavailability in Serbian river sediments.

Migration and speciation of heavy metal in salinized mine tailings affected by iron mining.

PubMed

Zhang, Xu; Yang, Huanhuan; Cui, Zhaojie

2017-10-01

The negative effects of heavy metals have aroused much attention due to their high toxicity to human beings. Migration and transformation trend of heavy metals have a close relationship with soil safety. Researching on migration and transformation of heavy metals in tailings can provide a reliable basis for pollution management and ecosystem restoration. Heavy metal speciation plays an important role in risk assessment. We chose Anshan tailings for our study, including field investigations and laboratory research. Four typical heavy metal elements of mine tailings {Fe (373.89 g/kg), Mn (2,303.80 mg/kg), Pb (40.99 mg/kg) and Cr (199.92 mg/kg)} were studied via Tessier test in vertical and horizontal direction. The main speciation of heavy metals in Anshan tailings was the residual. However, heavy metals have a strong ability for migration and transformation in vertical and horizontal directions. Its tendency to change from stable to unstable speciation results in increasing bioavailability and potential bioavailability. Fe, Mn, Pb and Cr showed different ability in the migration and transformation process (Mn > Pb > Fe > Cr) depending on the characteristics of heavy metals and physicochemical properties of the environment.

The effects of mass and metallicity upon planetary nebula formation

NASA Astrophysics Data System (ADS)

Papp, K. A.; Purton, C. R.; Kwok, S.

1983-05-01

A parameterized function is constructed which describes the possible dependence of planetary nebula formation upon metal abundance and stellar mass. Data on galaxies in the Local Group compared with predictions made from the parameterized function indicate that heavy element abundance is the principal agent influencing the formation of planetary nebulae; stars which are rich in heavy elements are the progenitors of planetary nebulae. This analysis, when compared with the observations, argues for a modest degree of pre-enrichment in a few of the sample galaxies. The heavy element dependence of planetary nebula formation also accounts for the deficit of planetary nebulae in the nuclei of NGC 221 and NGC 224, and in the bulge of our Galaxy.

Thermal stability of mullite RMn₂O₅ (R  =  Bi, Y, Pr, Sm or Gd): combined density functional theory and experimental study.

PubMed

Li, Chenzhe; Thampy, Sampreetha; Zheng, Yongping; Kweun, Joshua M; Ren, Yixin; Chan, Julia Y; Kim, Hanchul; Cho, Maenghyo; Kim, Yoon Young; Hsu, Julia W P; Cho, Kyeongjae

2016-03-31

Understanding and effectively predicting the thermal stability of ternary transition metal oxides with heavy elements using first principle simulations are vital for understanding performance of advanced materials. In this work, we have investigated the thermal stability of mullite RMn2O5 (R  =  Bi, Pr, Sm, or Gd) structures by constructing temperature phase diagrams using an efficient mixed generalized gradient approximation (GGA) and the GGA  +  U method. Simulation predicted stability regions without corrections on heavy elements show a 4-200 K underestimation compared to our experimental results. We have found the number of d/f electrons in the heavy elements shows a linear relationship with the prediction deviation. Further correction on the strongly correlated electrons in heavy elements could significantly reduce the prediction deviations. Our corrected simulation results demonstrate that further correction of R-site elements in RMn2O5 could effectively reduce the underestimation of the density functional theory-predicted decomposition temperature to within 30 K. Therefore, it could produce an accurate thermal stability prediction for complex ternary transition metal oxide compounds with heavy elements.

Toxicity of heavy metals and metal-containing nanoparticles on plants.

PubMed

Mustafa, Ghazala; Komatsu, Setsuko

2016-08-01

Plants are under the continual threat of changing climatic conditions that are associated with various types of abiotic stresses. In particular, heavy metal contamination is a major environmental concern that restricts plant growth. Plants absorb heavy metals along with essential elements from the soil and have evolved different strategies to cope with the accumulation of heavy metals. The use of proteomic techniques is an effective approach to investigate and identify the biological mechanisms and pathways affected by heavy metals and metal-containing nanoparticles. The present review focuses on recent advances and summarizes the results from proteomic studies aimed at understanding the response mechanisms of plants under heavy metal and metal-containing nanoparticle stress. Transport of heavy metal ions is regulated through the cell wall and plasma membrane and then sequestered in the vacuole. In addition, the role of different metal chelators involved in the detoxification and sequestration of heavy metals is critically reviewed, and changes in protein profiles of plants exposed to metal-containing nanoparticles are discussed in detail. Finally, strategies for gaining new insights into plant tolerance mechanisms to heavy metal and metal-containing nanoparticle stress are presented. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. Copyright © 2016 Elsevier B.V. All rights reserved.

Heavy metal contamination in the muscle of Aegean chub (Squalius fellowesii) and potential risk assessment.

PubMed

Şaşi, Hüseyin; Yozukmaz, Aykut; Yabanli, Murat

2018-03-01

Especially after the industrial revolution, the amount of contaminants released in aquatic ecosystems has considerably increased. For this reason, the necessity to carry on research on the existence of contaminants, specifically heavy metals, has emerged. In this study, heavy metal concentrations in muscle tissues of Aegean chub, which was an endemic species of south western part of Turkey, gathered from Tersakan River were examined. Heavy metal concentrations of the samples were analyzed with ICP-MS. Estimated daily intakes (EDI), target hazard quotient (THQ), and carcinogenic risk (CR) of elements were calculated. The heavy metals detected in muscle tissues were Zn > Cu > Cr > Mn > Pb > Cd, consecutively. According to the results of the applied health risk assessment (EDI, THQ and CR) for heavy metal exposure from fish consumption in children and adults, it was determined that there was no any significant threat to human health.

Contamination level, distribution and health risk assessment of heavy and toxic metallic and metalloid elements in a cultivated mushroom Pleurotus florida (Mont.) singer.

PubMed

Khani, Rouhollah; Moudi, Maryam; Khojeh, Vahid

2017-02-01

There are great concentrations of toxic metallic and metalloid elements such as lead, arsenic, mercury, cadmium or silver in many species of mushrooms comparative to other fruits and vegetables. In this study, contamination with heavy and toxic metallic and metalloid elements in the cultivated mushroom of (Pleurotus florida (Mont.) Singer) is investigated. P. florida was cultivated on different substrates; wheat straw (as blank), wheat straw + pine cone, wheat straw + soybean straw and wheat straw + urea and the effects of these substrates on contamination levels of Mn, Fe, Cu, Zn, As, Cd, and Pb were analyzed. The results showed that the concentrations of essential elements (Mn, Fe, Cu, and Zn) in the target mushroom are at the typical levels. The estimated daily intakes of studied metallic and metalloid elements were below their oral reference dosage mentioned by the international regulatory bodies. Health risk index (HRI) was calculated to evaluate the consumer's health risk assessment from the metal intake that contaminated in the cultivated mushroom of P. florida on the different nutrient sources. In this study, the individual HRIs were less than 1, which indicates insignificant potential health risk associated with the consumption of target mushroom from the studied substrates. Based on the HRIs values among the toxic metallic and metalloid elements, As in the target mushroom in the substrate of the wheat straw + pine cone is the main sources of risk, and it may cause severe health problems. Thus, this study suggests that the concentrations of heavy and toxic elements should be periodically monitored in cultivated mushrooms.

Effects of heavy metals on plants and resistance mechanisms. A state-of-the-art report with special reference to literature published in Chinese journals.

PubMed

Cheng, Shuiping

2003-01-01

As one of the consequences of heavy metal pollution in soil, water and air, plants are contaminated by heavy metals in some parts of China. To understand the effects of heavy metals upon plants and the resistance mechanisms, would make it possible to use plants for cleaning and remediating heavy metal-polluted sites. The research results on the effects of heavy metals on plants and resistant mechanisms are compiled from Chinese publications from scientific journals and university journals, mostly published during the last decade. Effects of heavy metals on plants result in growth inhibition, structure damage, a decline of physiological and biochemical activities as well as of the function of plants. The effects and bioavailability of heavy metals depend on many factors, such as environmental conditions, pH, species of element, organic substances of the media and fertilization, plant species. But, there are also studies on plant resistance mechanisms to protect plants against the toxic effects of heavy metals such as combining heavy metals by proteins and expressing of detoxifying enzyme and nucleic acid, these mechanisms are integrated to protect the plants against injury by heavy metals. There are two aspects on the interaction of plants and heavy metals. On one hand, heavy metals show negative effects on plants. On the other hand, plants have their own resistance mechanisms against toxic effects and for detoxifying heavy metal pollution. To study the effects of heavy metals on plants and mechanisms of resistance, one must select crop cultivars and/or plants for removing heavy metals from soil and water. More highly resistant plants can be selected especially for a remediation of the pollution site. The molecular mechanisms of resistance of plants to heavy metals should be studied further to develop the actual resistance of these plants to heavy metals. Understanding the bioavailability of heavy metals is advantageous for plant cultivation and phytoremediation. Decrease in the bioavailability to farmlands would reduce the accumulation of heavy metals in food. Alternatively, one could increase the bioavailability of plants to extract more heavy metals.

Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water

PubMed Central

Li, Jing; Yu, Haixin; Luan, Yaning

2015-01-01

The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant’s ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters. PMID:26703632

Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water.

PubMed

Li, Jing; Yu, Haixin; Luan, Yaning

2015-11-26

The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant's ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters.

Influence of urban activity in modifying water parameters, concentration and uptake of heavy metals in Typha latifolia L. into a river that crosses an industrial city.

PubMed

Strungaru, Stefan-Adrian; Nicoara, Mircea; Jitar, Oana; Plavan, Gabriel

2015-01-01

Heavy metals like Cu, Cd, Pb, Ni, Co and Cr can naturally be found almost all over this planet in various amounts. Urban activities such as heavy metal industry, traffic and waste can rapidly increase the metal concentrations in a fresh water ecosystem. This study was done in natural conditions to capture as many aspects in heavy metals pollution and bioremediation of Nicolina River, Romania considered a stream model which is under anthropogenic pressure. Water, sediment and leaves samples of Typha latifolia L. were collected during October 2013 and analyzed in order to assess certain heavy metals (Cu, Cd, Pb, Ni, Co and Cr) from each sampling site using GF-HR-CS-AAS with platform. Heavy metals in significant concentrations in cattail samples were correlated with the water parameters to show the possibility to use the cattail leaves as indicators in heavy metals pollution with potential in bioremediation because they can be easily harvested in autumn and this species is spread worldwide. The levels of metals concentrations in leaves were: Cu > Ni > Cr > Pb > Co knowing that copper is an essential element for plants. The sampling time was important to draw the river diagnosis for heavy metal pollution. The samples were collected, from river, after more than 60 days without rain same as a "human patient" prepared for blood test. Cobalt was considered the metal marker because it was an element with the lowest level of usage in the city. Compared with it only lead, cadmium and copper were used intensively in the industrial activities. T. latifolia L. can be use as an indicator for the health of the studied stream and it was noticed that the heavy metals were not accumulated, although the metal uptake was influenced by sediments and water parameters. The alkalinity of the studied river acts as an inhibitor in the bioremediation process of cattail for cadmium and copper. Lead was uptake by leaves and the water parameters influenced it but it wasn't concentrated enough in leaves to propose this species in lead bioremediation process for Nicolina River.

Expression analysis of metallothioneins and mineral contents in tomato (Lycopersicon esculentum) under heavy metal stress.

PubMed

Kısa, Dursun; Öztürk, Lokman; Doker, Serhat; Gökçe, İsa

2017-04-01

Heavy metals are considered to be the most important pollutants in the contamination of soils; they adversely affect plant growth and development and cause some physiological and molecular changes. The contamination of agricultural soils by heavy metals has changed the mineral element content of vegetables. Plant metallothioneins (MTs) are thought to have the functional role in heavy metal homeostasis, and they are used as the biomarkers for evaluating environmental pollution. We aimed to evaluate the expression of MT isoforms (MT1, 2, 3 and 4) and some mineral element composition of tomato roots, leaves and fruits exposed to copper and lead. Heavy metal applications increased MT1 and MT2 gene expressions compared to the control in the tissues of tomato. The highest level of MT1 and MT2 transcripts was found in roots and leaves, respectively. The expression of MT3 is induced in roots, leaves and fruits except for Pb treatment in roots. MT4 expression increased in fruits; however, other tissues did not show a clear change. Our results indicated that Cu content was higher than Pb in all tissues of tomato. The lower doses of Cu (10 ppm) increased the content of Mg, Fe, Ca and Mn in roots. Pb generally increased the level of minerals in leaves and fruits, but it decreased Mg, Mn and Fe contents in roots. Both heavy metals not only moved to aerial parts but also caused alterations to mineral element levels. These results show that MT transcripts are regulated by Cu and Pb, and expression pattern changes to MT isoforms and tissue types. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Improving crop tolerance to heavy metal stress by polyamine application.

PubMed

Soudek, Petr; Ursu, Marina; Petrová, Šárka; Vaněk, Tomáš

2016-12-15

Many areas have been heavily contaminated by heavy metals from industry and are not suitable for food production. The consumption of contaminated foods represents a health risk in humans, although some heavy metals are essential at low concentrations. Increasing the concentrations of essential elements in foods is one goal to improve nutrition. The aim of this study was to increase the accumulation of heavy metals in plant foods by the external application of putrescine. The levels of cadmium, zinc and iron were measured in different vegetables grown in hydroponic medium supplemented with heavy metals and compared with those grown in a reference medium. The estimated daily intake, based on the average daily consumption for various vegetable types, and the influence of polyamines on metal uptake were calculated. Copyright © 2016 Elsevier Ltd. All rights reserved.

"Periodic-table-style" paper device for monitoring heavy metals in water.

PubMed

Li, Miaosi; Cao, Rong; Nilghaz, Azadeh; Guan, Liyun; Zhang, Xiwang; Shen, Wei

2015-03-03

If a paper-based analytical device (μ-PAD) could be made by printing indicators for detection of heavy metals in chemical symbols of the metals in a style of the periodic table of elements, it could be possible for such μ-PAD to report the presence and the safety level of heavy metal ions in water simultaneously and by text message. This device would be able to provide easy solutions to field-based monitoring of heavy metals in industrial wastewater discharges and in irrigating and drinking water. Text-reporting could promptly inform even nonprofessional users of the water quality. This work presents a proof of concept study of this idea. Cu(II), Ni(II), and Cr(VI) were chosen to demonstrate the feasibility, specificity, and reliability of paper-based text-reporting devices for monitoring heavy metals in water.

Enhancing phytoextraction: the effect of chemical soil manipulation on mobility, plant accumulation, and leaching of heavy metals.

PubMed

Schmidt, Ulrich

2003-01-01

For heavy metal-contaminated agricultural land, low-cost, plant-based phytoextraction measures can be a key element for a new land management strategy. When agents are applied into the soil, the solubility of heavy metals and their subsequent accumulation by plants can be increased, and, therefore, phytoextraction enhanced. An overview is given of the state of the art of enhancing heavy metal solubility in soils, increasing the heavy metal accumulation of several high-biomass-yielding and metal-tolerant plants, and the effect of these measures on the risk of heavy metal leaching. Several organic as well as inorganic agents can effectively and specifically increase solubility and, therefore, accumulation of heavy metals by several plant species. Crops like willow (Salix viminalis L.), Indian mustard [Brassica juncea (L.) Czern.], corn (Zea mays L.), and sunflower (Helianthus annuus L.) show high tolerance to heavy metals and are, therefore, to a certain extent able to use the surpluses that originate from soil manipulation. More than 100-fold increases of lead concentrations in the biomass of crops were reported, when ethylenediaminetetraacetic acid (EDTA) was applied to contaminated soils. Uranium concentrations could be strongly increased when citric acid was applied. Cadmium and zinc concentrations could be enhanced by inorganic agents like elemental sulfur or ammonium sulfate. However, leaching of heavy metals due to increased mobility in soils cannot be excluded. Thus, implementation on the field scale must consider measures to minimize leaching. So, the application of more than 1 g EDTA kg(-1) becomes inefficient as lead concentration in crops is not enhanced and leaching rate increases. Moreover, for large-scale applications, agricultural measures as placement of agents, dosage splitting, the kind and amount of agents applied, and the soil properties are important factors governing plant growth, heavy metal concentrations, and leaching rates. Effective prevention of leaching, breeding of new plant material, and use of the contaminated biomass (e.g., as biofuels) will be crucial for the acceptance and the economic breakthrough of enhanced phytoextraction.

Influence of supercritical water treatment on heavy metals in medical waste incinerator fly ash.

PubMed

Bo, Da; Zhang, Fu-Shen; Zhao, Lijuan

2009-10-15

In this work, medical waste (MW) incinerator fly ashes from different types of incinerators were subjected to supercritical water (SCW) and SCW+H(2)O(2) (SCWH) treatments. Sequential extraction experiments showed that, after SCW treatment, heavy metals in exchangeable and carbonate forms in the ashes could be transferred into other relatively stable forms, e.g., Ba and Cr into residual fraction, Cu and Pb into organic matter fraction. SCWH treatment could stabilize heavy metals in Fe-Mn oxides and residual fractions. However, the behavior of As was quite different from heavy metals, which could be leached out from residue fraction after SCW and SWCH treatments. The leached As tended to absorb onto Fe-Mn oxides and organic matters under near neutral environment, but it could react with Ca(2+) at lower pH, increasing the mobility of this element. Therefore, it is necessary to neutralize acidic ash to near neutral condition before subjecting it to SCW and SCWH treatments so as to effectively stabilize hazardous elements in the ash. Consequently, it is believed that SCWH treatment is an effective alternative for hazardous elements detoxification in MW fly ash.

Hyperspectral estimation of soil heavy metals in Guanzhong area, Shaanxi province

NASA Astrophysics Data System (ADS)

Liu, Jinbao; Cheng, Jie; Wang, Huanyuan; Tong, Wei; Ma, Zenghui

2017-10-01

In this study, the contents of Cr, Mn, Ni, Cu, and Zn, As, Cd, Hg and Pub in 44 soil samples were collected from Fufeng County, Yangling County and Wugong County, Shaanxi Province and were used as data sources. ASD Field Spec HR (350 ˜ 2500 nm), and then the NOR, MSC and SNV of the reflectance were pretreated, the first deviation, second deviation and reflectance reciprocal logarithmic transformation were carried out. The optimal hyper spectral estimation model of nine heavy metal elements of Cr, Mn, Ni, Cu, and Zn, As, Cd, Hg and Pb was established by regression method. Comparing the reflection characteristics of different heavy metal contents and the effect of different pretreatment methods on the establishment of soil heavy metal spectral inversion model. The results show that: (1) the reflectance spectrum improves the signal-to-noise ratio of the reflectance spectrum after the transformation of NOR, MSC and SNV. Combining differential transformation can improve the information of heavy metal elements in the soil, and use the correlation band energy significantly improve the stability and predictability of the model. (2) The modeling accuracy of the optimal model of nine heavy metal spectra of Cr, Mn, Ni, Cu, and Zn, As, Cd, Hg and Pb by PLSR method were 0.7002, 0.7852, 0.687, 0.8036, 0.8619, 0.5765, 0.5451, 0.9912, and 0.6182.

[Ecological risk evaluation of heavy metals of the typical dredged mud in Shanghai].

PubMed

Tang, Qing-Li; Cheng, Jin-Ping; Gao, Hao-Min; Yao, Lei; Jiang, Zhen-Yi; Wu, Yang; Xie, Cui-Song; Liang, Hai; Wang, He; Pi, Shuai-Shuai; Yu, Zhao-Yi

2013-04-01

In order to discuss the potential ecological risk of heavy metals of the typical dredged mud in Shanghai, the Hakanson potential ecological risks method was used to analyse and assess the potential ecological risks of heavy metals, including Hg, Cd, Cu, Pb, As,Cr and Zn in dredged mud from the following three areas-the dock apron of Huangpu River, the mouth of the Yangtze River and inland waterways. The results showed that the mean values of ecological risk index (Er(i)) of the seven heavy metals are 20.05, 17.49, 8.82, 5.71, 4.68, 1.74 and 1.13, respectively, all of which belonged to the low ecological risk; Cd (one location in inland waterways) and Hg (three locations in the mouth of the Yangtze River and one location in inland waterways) are the most hazardous elements, with the Er(i) > 40, which belonged to the medium ecological risk or the high ecological risk, and other elements belonged to the low ecological risk. From the results of ecological risk indices(ERI) of the heavy metals in Shanghai dredged mud, the risk of the heavy metals belonged to the low ecological risk. The ERI of inland waterways, the mouth of the Yangtze River and the dock apron of the Huangpu River were 81.4, 57.7 and 52.5, respectively, which all belong to the low ecological risk.

Source identification and spatial distribution of heavy metals in tobacco-growing soils in Shandong province of China with multivariate and geostatistical analysis.

PubMed

Liu, Haiwei; Zhang, Yan; Zhou, Xue; You, Xiuxuan; Shi, Yi; Xu, Jialai

2017-02-01

Samples of surface soil from tobacco (Nicotiana tabacum L.) fields were analysed for heavy metals and showed the following concentrations (mean of 246 samples, mg/kg): As, 5.10; Cd, 0.11; Cr, 49.49; Cu, 14.72; Hg, 0.08; Ni, 19.28; Pb. 20.20 and Zn, 30.76. The values of the index of geoaccumulation (I geo ) and of the enrichment factor indicated modest enrichment with As, Cd, Cr, Hg, Ni or Pb. Principal component analysis and cluster analysis correctly allocated each investigated element to its source, whether anthropogenic or natural. The results were consistent with estimated inputs of heavy metals from fertilizers, irrigation water and atmospheric deposition. The variation in the concentrations of As, Cd, Cu, Pb and Zn in the soil was mainly due to long-term agricultural practises, and that of Cr and Ni was mainly due to the soil parent material, whereas the source of Hg was industrial activity, which ultimately led to atmospheric deposition. Atmospheric deposition was the main exogenous source of heavy metals, and fertilizers also played an important role in the accumulation of these elements in soil. Identifying the sources of heavy metals in agricultural soils can serve as a basis for appropriate action to control and reduce the addition of heavy metals to cultivated soils.

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops*

PubMed Central

Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

2007-01-01

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity. PMID:17173356

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops.

PubMed

Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

2007-01-01

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity.

Risk Assessment of Heavy Metal Pollution in Soils of Gejiu Tin Ore and Other Metal Deposits of Yunnan Province

NASA Astrophysics Data System (ADS)

Yang, Shuran; Danek, Tomas; Cheng, Xianfeng; Huang, Qianrui

2017-12-01

This paper aims to study three main metal mining areas in Yunnan Province, to summarize and analyze the heavy metal pollution situation in each mining area, and to assess the ecological risk of the mining areas. The results showed that heavy metal pollution existed in different regions of the three mining areas with pollution elements of Cd, As, Cu, Pb, Zn. Risk level, besides Zhen Yuan mining area (class C), for the other two areas was class D, with Beichang mining area in Lanping as the most serious polluted mining area.

Finite element modeling simulation-assisted design of integrated microfluidic chips for heavy metal ion stripping analysis

NASA Astrophysics Data System (ADS)

Hong, Ying; Zou, Jianhua; Ge, Gang; Xiao, Wanyue; Gao, Ling; Shao, Jinjun; Dong, Xiaochen

2017-10-01

In this article, a transparent integrated microfluidic device composed of a 3D-printed thin-layer flow cell (3D-PTLFC) and an S-shaped screen-printed electrode (SPE) has been designed and fabricated for heavy metal ion stripping analysis. A finite element modeling (FEM) simulation is employed to optimize the shape of the electrode, the direction of the inlet pipeline, the thin-layer channel height and the sample flow rate to enhance the electron-enrichment efficiency for stripping analysis. The results demonstrate that the S-shaped SPE configuration matches the channel in 3D-PTLFC perfectly for the anodic stripping behavior of the heavy metal ions. Under optimized conditions, a wide linear range of 1-80 µg l-1 is achieved for Pb2+ detection with a limit of 0.3 µg l-1 for the microfluidic device. Thus, the obtained integrated microfluidic device proves to be a promising approach for heavy metal ions stripping analysis with low cost and high performance.

Impact evaluation of the industrial activities in the Bay of Bakar (Adriatic Sea, Croatia): recent benthic foraminifera and heavy metals.

PubMed

Popadić, Adriana; Vidović, Jelena; Cosović, Vlasta; Medaković, Davorin; Dolenec, Matej; Felja, Igor

2013-11-15

The Bay of Bakar is one of the most heavily polluted bays at the Eastern Adriatic. Three major industrial companies potentially endanger the bay. The concentration of major, minor and trace elements in surface sediments from thirteen stations was discussed in relation to the sediment type and foraminiferal assemblages. The distribution of major elements in the bay is influenced by geological nature of surroundings. Heavy metal distribution depends on pollution sources and on amount of mud fraction: fine-grained sediments are enriched by them in comparison with coarse-grained ones. Different sediment quality criteria complicate the pollution assessment in the bay. Heavy metal concentrations generally fall into allowed depositional values for marine environments; only area in front of the coke plant and the City of Bakar harbor is heavily polluted. Stress-tolerant foraminiferal species dominate at stations with higher concentrations of heavy metals and coarse-grained sediments consist of larger number of epifaunal taxa. Copyright © 2013 Elsevier Ltd. All rights reserved.

Contribution of GIS to evaluate surface water pollution by heavy metals: Case of Ichkeul Lake (Northern Tunisia)

NASA Astrophysics Data System (ADS)

Yazidi, Amira; Saidi, Salwa; Ben Mbarek, Nabiha; Darragi, Fadila

2017-10-01

The concentrations of nutrients and heavy elements in the surface water of the lake Ichkeul, main wadis which feed directly and thermal springs that flow into the lake, are measured to evaluate these chemical elements. There are used to highlight the interactions between these different aquatic compartments of Ichkeul. All metal concentrations in lake water, except Cu, were lower than the maximum permitted concentration for the protection of aquatic life. The results show that the highest concentrations are located in the eastern and south-eastern part of the lake where the polluted water comes from the lagoon of Bizerte through the wadi Tinja as well as from the city of Mateur through the wadi Joumine. The pollution indices and especially the heavy metal evaluation index (HEI) show high pollution specially located at the mouths of wadis and an increase of heavy metal concentrations, as a result of uncontrolled releases of domestic and industrial wastewater.

[Study on distribution characteristics and potential ecological risk of soil heavy metals in the Yellow River beach region in Kaifeng City].

PubMed

Zhang, Peng-yan; Qin, Ming-zhou; Chen, Long; Hu, Chang-hui; Zhao, Ya-ping; Dong, Wei-jun

2013-09-01

The distributions, soil environment status and potential ecological risk of heavy metals were studied in beach soil of returning the cropland into Yellow River beach region in Kaifeng by the Nemerows and Håkansons methods. The results showed that (1) as Among the average contents of the five heavy metals Pb, Cr, Hg, As and Cd, the highest was the average content of Cr, and the lowest was the average content of Pb and Hg. In addition to Hg, the coefficients of variation of other heavy metals were relatively small, indicating that the content of heavy metals was quite different at different sites, and to some extent, relecting that Hg, As and Pb were the major elements polluting the soil, among which, Pb pollution was the pollution with universality. There was little difference in the contents of Cr and Cd from village to village the coefficient of variation was small, and the contents were below the national standard level. (2) There was significant difference in the spatial distribution of soil heavy metal elements in the upper, the middle and lower sections of the study area. The upper section was clean, the middle section was slightly polluted, and the lower section was enriched with pollutants. (3) The distribution of heavy metals in the beach region inside and outside the levees of Yellow River was closely related to the distribution of the residential regions. In the upper section of the beach region (southwest), the population was large and the contents of heavy metals were high. The contents of heavy metals were lower in the near river zone than outside the levees of Yellow River. And the heavy metal contents in the middle and lower section were higher than those outside the levees of Yellow River, while the lower section (northwest) showed a tendency of pollution enrichment. (4) In the view of the average individual potential ecological risk index of heavy metals (E(r)i), the potential ecological risk of Hg reached intense levels, and the potential ecological risk of Pb's contribution to the integrated risk was 50.5%, which was the heavy metal with highest ecological risks. Cd and Pb had a moderate ecological risk, while As and Cr had minor ecological risk. Ecological hazards of heavy metals ranked in the ascending order of Hg > Pb > As > Cd > Cr. (5) The ecological hazard of the heavy metals was ranked in the order Hg > Cd > As > Pb > Cr. Based on the potential ecological risk level corresponding to the RI values, it was shown that there was moderate potential ecological risks of heavy metals in the Yellow River beach region in Kaifeng.

Genesis of the heaviest elements in the Milky Way Galaxy.

PubMed

Sneden, Christopher; Cowan, John J

2003-01-03

We review the origin and evolution of the heavy elements, those with atomic numbers greater than 30, in the early history of the Milky Way. There is a large star-to-star bulk scatter in the concentrations of heavy elements with respect to the lighter metals, which suggests an early chemically unmixed and inhomogeneous Galaxy. The relative abundance patterns among the heavy elements are often very different from the solar system mix, revealing the characteristics of the first element donors in the Galaxy. Abundance comparisons among several halo stars show that the heaviest neutron-capture elements (including barium and heavier) are consistent with a scaled solar system rapid neutron-capture abundance distribution, whereas the lighter such elements do not conform to the solar pattern. The stellar abundances indicate an increasing contribution from the slow neutron-capture process (s-process) at higher metallicities in the Galaxy. The detection of thorium in halo and globular cluster stars offers a promising, independent age-dating technique that can put lower limits on the age of the Galaxy.

Selenite reduction by the obligate aerobic bacterium Comamonas testosteroni S44 isolated from a metal-contaminated soil

PubMed Central

2014-01-01

Background Selenium (Se) is an essential trace element in most organisms but has to be carefully handled since there is a thin line between beneficial and toxic concentrations. Many bacteria have the ability to reduce selenite (Se(IV)) and (or) selenate (Se(VI)) to red elemental selenium that is less toxic. Results A strictly aerobic bacterium, Comamonas testosteroni S44, previously isolated from metal(loid)-contaminated soil in southern China, reduced Se(IV) to red selenium nanoparticles (SeNPs) with sizes ranging from 100 to 200 nm. Both energy dispersive X-ray Spectroscopy (EDX or EDS) and EDS Elemental Mapping showed no element Se and SeNPs were produced inside cells whereas Se(IV) was reduced to red-colored selenium in the cytoplasmic fraction in presence of NADPH. Tungstate inhibited Se(VI) but not Se(IV) reduction, indicating the Se(IV)-reducing determinant does not contain molybdenum as co-factor. Strain S44 was resistant to multiple heavy and transition metal(loid)s such as Se(IV), As(III), Cu(II), and Cd(II) with minimal inhibitory concentrations (MIC) of 100 mM, 20 mM, 4 mM, and 0.5 mM, respectively. Disruption of iscR encoding a transcriptional regulator negatively impacted cellular growth and subsequent resistance to multiple heavy metal(loid)s. Conclusions C. testosteroni S44 could be very useful for bioremediation in heavy metal(loid) polluted soils due to the ability to both reduce toxic Se(VI) and Se(IV) to non-toxic Se (0) under aerobic conditions and to tolerate multiple heavy and transition metals. IscR appears to be an activator to regulate genes involved in resistance to heavy or transition metal(loid)s but not for genes responsible for Se(IV) reduction. PMID:25098921

Micro-PIXE studies of elemental distribution in Cd-accumulating Brassica juncea L.

NASA Astrophysics Data System (ADS)

Schneider, Thorsten; Haag-Kerwer, Angela; Maetz, Mischa; Niecke, Manfred; Povh, Bogdan; Rausch, Thomas; Schüßler, Arthur

1999-10-01

Brassica juncea L. is a high biomass producing crop plant, being able to accumulate Cd and other heavy metals in their roots and shoots. It is a good candidate for efficient phytoextraction of heavy metals - such as Cd - from polluted soils. PIXE and STIM analyses were applied to investigate Cd-uptake in roots and the resulting effects on the elemental distribution of Cd stressed plants. The axial distribution of trace elements as a function of distance from the root tip as well as the radial distribution within cross-sections were analysed. The results are compared with the elemental distribution in control plants.

Ionomics: Genes and QTLs controlling heavy metal uptake in perennial grasses grown on phytoxic soil

USDA-ARS?s Scientific Manuscript database

Perennial grasses occupy diverse soils throughout the world, including many sites contaminated with heavy metals. Uncovering the genetic architecture of QTLs controlling mineral homoeostasis is critical for understanding the biochemical pathways that determine the elemental profiles of perennial pl...

FOOD CHAIN TRANSFER AND BIOAVAILABILITY OF CD AND OTHER ELEMENTS IN PLANTS GROWN ON BIOSOLIDS AMENDED SOILS

EPA Science Inventory

Application of biosolids, livestock manures, compost, and many byproducts add heavy metals to soil. Exposure of humans, livestock and wildlife to these added heavy metals continues to be a concern despite the research and risk assessments which suggest otherwise. Key concepts gov...

HAIR HEAVY METAL AND ESSENTIAL TRACE ELEMENT CONCENTRATION IN CHILDREN WITH AUTISM SPECTRUM DISORDER.

PubMed

Tabatadze, T; Zhorzholiani, L; Kherkheulidze, M; Kandelaki, E; Ivanashvili, T

2015-11-01

Our study aims evaluation of level of essential trace elements and heavy metals in the hair samples of children with autistic spectrum disorder (ASD) and identification of changes that are associated with autistic spectrum disorders. Case-control study was conducted at Child Development Center of Iashvili Children's Central Hospital (LD).We studied 60 children aged from 4 to 5 years old. The concentrations of 28 elements among (Ca,Zn, K, Fe, Cu, Se, Mn, Cr, S, Br, Cl, Co, Ag, V, Ni, Rb, Mo, Sr, Ti, Ba, Pb, As, Hg, Cd, Sb, Zr, Sn, Bi) them trace elements and toxic metals) were determined in scalp hair samples of children (n=30) with autistic spectrum disorder (ASD) and from control group of healthy children (n=30) with matched sex and age. Micro-elemental status was detected in the hair, with roentgen-fluorescence spectrometer method (Method MBИ 081/12-4502-000, Apparatus ALVAX- CIP, USA - UKRAIN) .To achieve the similarity of study and control groups, pre and postnatal as well as family and social history were assessed and similar groups were selected. Children with genetic problems, malnourished children, children from families with social problems were excluded from the study. The diagnosis of ASD were performed by pediatrician and psychologist (using M-CHAT and ADOS) according to DSM IV (Diagnostic and Statistical Manual of Mental Disorders from the American Psychiatric association) criteria. The study was statistically analyzed using computer program SPSS 19. Deficiencies of essential trace microelements revealed in both group, but there was significant difference between control and studied groups. The most deficient element was zinc (92% in target and 20% in control), then - manganese (55% and 8%) and selenium (38% and 4%). In case of cooper study revealed excess concentration of this element only in target group in 50% of cases. The contaminations to heavy metals were detected in case of lead (78% and 16), mercury (43% and 10%) and cadmium (38% and 8%). The study statistical results indicated, that deficient concentrations of trace elements such as zinc, manganese, molybdenum and selenium in hair significantly linked with ASD (Kramer's V was 0,740; 0,537; 0,333; 0,417 accordingly). In case of cooper we got excess levels of this element and this data was highly linked with autism spectrum disorder. We got high associations and significant values between of lead, mercury and cadmium concentrations and ASD. Study results indicate that there are significant differences of hair essential trace elements concentrations in children with autism spectrum disorder comparing with healthy children group. The result obtained also showed high contamination to heavy metals such as lead, mercury and cadmium in ASD children compared to healthy ones. So, our study demonstrated alteration in levels of toxic heavy metals and essential trace elements in children with autistic spectrum disorders as compared to healthy children. This suggests a possible pathophysiological role of heavy metals and trace elements in the genesis of symptoms of autism spectrum disorders.

Effects of heavy metals on sea urchin embryo development. Part 2. Interactive toxic effects of heavy metals in synthetic mine effluents.

PubMed

Kobayashi, Naomasa; Okamura, Hideo

2005-12-01

Interactive toxic effects between heavy metals were investigated using a sea urchin (Anthocidaris crassispina) bioassay. An effluent from an abandoned mine showed significant inhibitory effects on embryo development as well as producing specific malformations. The effects on the embryos were reproduced by synthetic polluted seawater consisting of eight metals (manganese, lead, cadmium, nickel, zinc, chromium, iron, and copper) at the concentrations detected in the mine effluent. This indicated that the heavy metals were responsible for the effects observed. Five heavy metals were ranked in decreasing order of toxicity as follows: Cu>Zn>Pb>Fe>Mn. Among these, zinc and manganese could cause malformation of the embryos. From bioassay results using 27 combinations of heavy metals, 16 combinations including zinc could produce specific malformations, such as radialized, exo-gastrulal, and spaceship Apollo-like gastrulal embryos. Zinc was one of the elements responsible for causing malformations and its effects were intensified by the presence of the other metals, such as manganese, lead, iron, and copper.

Temporal trends and bioavailability assessment of heavy metals in the sediments of Deception Bay, Queensland, Australia.

PubMed

Brady, James P; Ayoko, Godwin A; Martens, Wayde N; Goonetilleke, Ashantha

2014-12-15

Thirteen sites in Deception Bay, Queensland, Australia were sampled three times over a period of 7 months and assessed for contamination by a range of heavy metals, primarily As, Cd, Cr, Cu, Pb and Hg. Fraction analysis, enrichment factors and Principal Components Analysis-Absolute Principal Component Scores (PCA-APCS) analysis were conducted in order to identify the potential bioavailability of these elements of concern and their sources. Hg and Te were identified as the elements of highest enrichment in Deception Bay while marine sediments, shipping and antifouling agents were identified as the sources of the Weak Acid Extractable Metals (WE-M), with antifouling agents showing long residence time for mercury contamination. This has significant implications for the future of monitoring and regulation of heavy metal contamination within Deception Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acute toxicity and synergism of cadmium and zinc in white shrimp, Penaeus setiferus, Juveniles

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

Vanegas, C.; Espina, S.; Botello, A.V.

1997-01-01

Toxic effects of individual heavy metals on decapod crustaceans have been reported frequently, but little information exists concerning interactions. Among the non-essential heavy metals, cadmium is one of the most hazardous elements in the aquatic environment; on the other hand, zinc is an essential element, but toxic when present in greater than trace amounts. Biological effects of cadmium in aquatic organisms are complex due to the interactions with both environmental variables and other toxic agents. In decapod crustaceans, the toxicity of cadmium and zinc is modified by salinity, temperature, hypoxia, calcium ion concentrations and life-cycle stage. Heavy metal pollution hasmore » increased in the coastal waters of the Gulf of Mexico, particularly in shrimp habitat. This study examined the toxicity of cadmium and zinc to white shrimp juveniles and looked at the interaction of the metals. 16 refs., 2 tabs.« less

Multivariate classification of edible salts: Simultaneous Laser-Induced Breakdown Spectroscopy and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry Analysis

NASA Astrophysics Data System (ADS)

Lee, Yonghoon; Nam, Sang-Ho; Ham, Kyung-Sik; Gonzalez, Jhanis; Oropeza, Dayana; Quarles, Derrick; Yoo, Jonghyun; Russo, Richard E.

2016-04-01

Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), both based on laser ablation sampling, can be employed simultaneously to obtain different chemical fingerprints from a sample. We demonstrated that this analysis approach can provide complementary information for improved classification of edible salts. LIBS could detect several of the minor metallic elements along with Na and Cl, while LA-ICP-MS spectra were used to measure non-metallic and trace heavy metal elements. Principal component analysis using LIBS and LA-ICP-MS spectra showed that their major spectral variations classified the sample salts in different ways. Three classification models were developed by using partial least squares-discriminant analysis based on the LIBS, LA-ICP-MS, and their fused data. From the cross-validation performances and confusion matrices of these models, the minor metallic elements (Mg, Ca, and K) detected by LIBS and the non-metallic (I) and trace heavy metal (Ba, W, and Pb) elements detected by LA-ICP-MS provided complementary chemical information to distinguish particular salt samples.

Analysis of heavy metals (Pb and Zn) concentration in sediment of Blanakan fish ponds, Subang, West Java

NASA Astrophysics Data System (ADS)

Wiriawan, A.; Takarina, N. D.; Pin, T. G.

2017-07-01

Blanakan fish ponds receive water resource from Kali Malang and Blanakan rivers. Industrial and domestic activities along the river can cause pollution, especially heavy metals. Zinc (Zn) is an essential element that needed by an organism, while Lead (Pb) is a nonessential element that is not needed. Discharge of waste water from industries and anthropogenic activities continuously not only pollute the water but also the sediment and biota live on it. This research was aimed to know the heavy metals content in the sediment of Blanakan fish ponds. Sediment samples were taken on July and August 2016 at three locations. Heavy metals were analyzed using Atomic Absorption Spectrophotometry (AAS) Shimadzu 6300. The result of Lead (Pb) measurement showed that Fish Pond 1 had higher average concentration compared Fish Pond 2 and Fish Pond 3 which was 0.55 ppm. Standard for Lead (Pb) in sediment according to Ontario Sediment Standards (2008) is 31 ppm. Based on Zinc (Zn) measurement, it was known that average of Zinc (Zn) concentration also higher on Fish Pond 1 compared to Fish Pond 2 and 3 which was 1.93 ppm. According to Ontario Sediment Standards (2008), a standard for Zinc (Zn) in sediment is 120 ppm. This indicated that heavy metals in the sediment of fish ponds were below standards. Statistical analysis using t-test showed that there was no significant difference of heavy metals content among fish ponds.

Chelate-assisted phytoextraction of heavy metals in a soil contaminated with a pyritic sludge.

PubMed

Peñalosa, Jesus Manuel; Carpena, Ramón O; Vázquez, Saúl; Agha, Ramsy; Granado, Ana; Sarro, María José; Esteban, Elvira

2007-05-25

The occurrence of many polluted areas as that affected by the accident of the Aznalcóllar pyrite mine has promoted phytoremediation as a technology able to reduce the risk of heavy metal contamination at low cost. White lupin plant has been considered a good candidate for phytoremediation. We studied the capacity of several complexing agents to improve the ability of white lupin for heavy metal phytoremediation in soils with multi-elemental pollution from acid pyritic sludge. Solution-soil interaction was studied and pot experiments with sludge-affected soil were carried out to this end. The interaction experiments indicated that EDTA and NTA were more efficient than malate and citrate in solubilizing metals (Fe, Mn, Cu, Zn, Cd), with minimum differences between EDTA and NTA. The pot trial showed that NTA was able to mobilize toxic elements from sludge-polluted soil and hence increasing their concentrations in plant (Mn, Cu, Zn, As, Cd). However, the NTA treatment promoted an increase of toxic elements concentrations, especially for As, Cd, Pb, in the lixiviates exceeding the maximum permissible levels, so a careful management of chelate is necessary.

Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China

PubMed Central

Yang, Jie; Teng, Yanguo; Song, Liuting; Zuo, Rui

2016-01-01

Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn). The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment) > Zn, Ni, Cr, Fe, and Mn (moderate enrichment) > Cd and Ni (minimal enrichment). Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area. PMID:27992518

Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China.

PubMed

Yang, Jie; Teng, Yanguo; Song, Liuting; Zuo, Rui

2016-01-01

Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn). The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment) > Zn, Ni, Cr, Fe, and Mn (moderate enrichment) > Cd and Ni (minimal enrichment). Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area.

Multi-element analysis of water decoction of medicine food homology plants using inductively coupled plasma-tandem mass spectrometry

NASA Astrophysics Data System (ADS)

Fu, Liang; Shi, Shu-Yun; Chen, Xiao-Qing

2017-07-01

The concentration of twelve trace elements in the water decoction of medicine food homology plants (MFHP) was determined by inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS). Water decoctions of MFHP were analyzed directly using the MS/MS mode after acidification by 1% (v/v) nitric acid. The polyatomic interferences were eliminated by oxygen mass shift, oxygen on-mass, and ammonia mass shift. The accuracy of the method was verified by analysis of standard reference materials. This method was utilized to investigate the water decoction composition of 16 common Chinese MFHPs. The trace elements in the water decoctions of different MFHPs presented significantly different dissolution ratios. The dissolution ratio of V was the lowest (4.21%-14.86%), whereas Zn showed the highest dissolution ratio (24.87%-86.80%). In addition, the dissolution ratio of heavy metallic elements in most MFHP was equal to or was lower than 30%. Therefore, consumption of MHFP decoction could decrease the heavy metal intake associated with MFHP use and reduce the risk of heavy metal poisoning.

Relative extraction ratio (RER) for arsenic and heavy metals in soils and tailings from various metal mines, Korea.

PubMed

Son, Hye Ok; Jung, Myung Chae

2011-01-01

This study focused on the evaluation of leaching behaviours for arsenic and heavy metals (Cd, Cu, Ni, Pb and Zn) in soils and tailings contaminated by mining activities. Ten representative mine soils were taken at four representative metal mines in Korea. To evaluate the leaching characteristics of the samples, eight extraction methods were adapted namely 0.1 M HCl, 0.5 M HCl, 1.0 M HCl, 3.0 M HCl, Korean Standard Leaching Procedure for waste materials (KSLP), Synthetic Precipitation Leaching Procedure (SPLP), Toxicity Characteristic Leaching Procedure (TCLP) and aqua regia extraction (AR) methods. In order to compare element concentrations as extraction methods, relative extraction ratios (RERs, %), defined as element concentration extracted by the individual leaching method divided by that extracted by aqua regia based on USEPA method 3050B, were calculated. Although the RER values can vary upon sample types and elements, they increase with increasing ionic strength of each extracting solution. Thus, the RER for arsenic and heavy metals in the samples increased in the order of KSLP < SPLP < TCLP < 0.1 M HCl < 0.5 M HCl < 1.0 M HCl < 3.0 M HCl. In the same extraction method, the RER values for Cd and Zn were relatively higher than those for As, Cu, Ni and Pb. This may be due to differences in geochemical behaviour of each element, namely high solubility of Cd and Zn and low solubility of As, Cu, Ni and Pb in surface environment. Thus, the extraction results can give important information on the degree and extent of arsenic and heavy metal dispersion in the surface environment.

Heavy metal analysis in commercial Spirulina products for human consumption

PubMed Central

Al-Dhabi, Naif Abdullah

2013-01-01

For consumption of health foods of Spirulina, by the general public, health food stores are increasingly offering more exotic products. Though Spirulina consumption is growing worldwide, relatively few studies have reported on the quantities of heavy metals/minerals they contain and/or their potential effects on the population’s health. This study reveals the concentrations of six typical heavy metals/minerals (Ni, Zn, Hg, Pt, Mg, and Mn) in 25 Spirulina products commercialized worldwide for direct human consumption. Samples were ground, digested and quantified by Coupled Plasma Mass Spectroscopy (ICP–MS). The concentrations (mg/kg d.w.) were range from 0.001 to 0.012 (Pt) followed by 0.002–0.028 (Hg), 0.002–0.042 (Mg), 0.005–2.248 (Mn), 0.211–4.672 (Ni) and 0.533–6.225 (Zn). The inorganic elements of the present study were significantly lower than the recommended daily intake (RDI) level of heavy metal elements (mg/daily) Ni (0.4), Zn (13), Hg (0.01), Pt (0.002), Mg (400) and Mn (4). Based on this study the concentration of inorganic elements was not found to exceed the present regulation levels, and they can be considered as safe food. PMID:24235875

[Standard sample preparation method for quick determination of trace elements in plastic].

PubMed

Yao, Wen-Qing; Zong, Rui-Long; Zhu, Yong-Fa

2011-08-01

Reference sample was prepared by masterbatch method, containing heavy metals with known concentration of electronic information products (plastic), the repeatability and precision were determined, and reference sample preparation procedures were established. X-Ray fluorescence spectroscopy (XRF) analysis method was used to determine the repeatability and uncertainty in the analysis of the sample of heavy metals and bromine element. The working curve and the metrical methods for the reference sample were carried out. The results showed that the use of the method in the 200-2000 mg x kg(-1) concentration range for Hg, Pb, Cr and Br elements, and in the 20-200 mg x kg(-1) range for Cd elements, exhibited a very good linear relationship, and the repeatability of analysis methods for six times is good. In testing the circuit board ICB288G and ICB288 from the Mitsubishi Heavy Industry Company, results agreed with the recommended values.

Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium.

PubMed

Senesi, G S; Dell'Aglio, M; Gaudiuso, R; De Giacomo, A; Zaccone, C; De Pascale, O; Miano, T M; Capitelli, M

2009-05-01

Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation temperatures and comparable electron number density measured for all samples. An index of the anthropogenic contribution of Cr in polluted soils was calculated in comparison to a non-polluted reference soil. Thus, the intensity ratios of the emission lines of heavy metal can be used to detect in few minutes the polluted areas for which a more detailed sampling and analysis can be useful.

Evaluating the potential use of Tamarix gallica L. for phytoremediation practices in heavy-metal polluted soils

NASA Astrophysics Data System (ADS)

Abou Jaoudé, R.; Pricop, A.; Laffont-Schwob, I.; Prudent, P.; Rabier, J.; Masotti, V.; de Dato, G.; De Angelis, P.

2012-04-01

The rapid growth of population, the increased urbanisation and the expansion of industrial activities have provoked an augmented occurrence of soil contamination by heavy-metals. Important sources of contamination are industrial, mining and military infrastructures, which are often abandoned without performing the appropriate reclamation work. In the Mediterranean Basin, where coastal areas are largely affected by human overexploitation, the use of species able to tolerate heavy-metals and other abiotic stresses may represent a low-cost solution for phytoremediation in these harsh environments. Tamarix gallica L. is a widespread species in coastal Mediterranean areas, showing a high adaptability to different environments and a high tolerance of adversity. With the objective of testing local species as candidates for phytoremediation practices in heavy-metal contaminated coastal soils, cuttings of T. gallica from a wild population around Marseille (France) were planted in pots containing: 1) control soil (loamy soil and sand (2/1)), 2) half-polluted soil (loamy soil, sand and heavy-metal polluted soil (1/1/1)), and 3) polluted soil (sand and heavy-metal polluted soil (1/2)). The contaminated soils were collected in the surrounding of a former lead industry of Marseille littoral and characterised by the presence of Fe, Pb, Zn, As and Al. After three months from planting, leaf functionality was evaluated by measuring leaf gas exchanges, leaf chlorophyll fluorescence and, chlorophyll, phenols, flavonoids and anthocyanins contents. SEM observations coupled to EDXS analysis were used to determine elements (Pb, As and Al) presence and location on the leaf surface and in leaf and root tissues. T. gallica was moderately affected by the presence of heavy-metals in the soil treatments. In fact, a reduction in stomatal conductance was only observed in plants grown in the polluted soil. This reduction did not cause a significant decrease in CO2 assimilation rates. Moreover, the presence of Al on the root surface was observed in plants grown in polluted soils; this element was not detected in leaf tissues or in the leaf extruded material, suggesting a phytostabilization effect for this element. In conclusion, T. gallica could be a potential candidate for phytoremediation practices. Nevertheless, field experiments will be necessary to assess growth performances and phytoremediation potential of this species in heavy-metal polluted areas.

Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. II. Zinc binding inside leaf cell organelles.

PubMed

Vollenweider, Pierre; Bernasconi, Petra; Gautschi, Hans-Peter; Menard, Terry; Frey, Beat; Günthardt-Goerg, Madeleine S

2011-01-01

The phytoextraction potential of plants for removing heavy metals from polluted soils is determined by their capacity to store contaminants in aboveground organs and complex them safely. In this study, the metal compartmentation, elemental composition of zinc deposits and zinc complexation within leaves from poplars grown on soil with mixed metal contamination was analysed combining several histochemical and microanalytical approaches. Zinc was the only heavy metal detected and was stored in several organelles in the form of globoid deposits showing β-metachromasy. It was associated to oxygen anions and different cations, noteworthy phosphorous. The deposit structure, elemental composition and element ratios indicated that zinc was chelated by phytic acid ligands. Maturation processes in vacuolar vs. cytoplasmic deposits were suggested by differences in size and amounts of complexed zinc. Hence, zinc complexation by phytate contributed to metal detoxification and accumulation in foliage but could not prevent toxicity reactions therein. Copyright © 2010 Elsevier Ltd. All rights reserved.

Wastewater and sludge reuse in agriculture

NASA Astrophysics Data System (ADS)

Kalavrouziotis, Ioannis

2016-04-01

The reuse of Municipal wastewaters (TMWW) for irrigation of crops, and of sludge for the amendment of soils, is a multidimensional disposal practice aiming at: (i) minimizing the environmental problems by releasing the pressure exerted by these two inputs on the environment, (ii) providing the growing plants with water and nutrients and (ii) improving soil fertility and productivity, The research work conducted in our University in relation to accomplishing a safe reuse has been focused on the study of the following aspects of reuse: (i) heavy metal accumulation in soils and plants with emphasis on their edible part. This aspect has been studied by conducting a series of experiments aiming at the study of the accumulation of heavy metals in soils, and in plant roots, stalks, leaves and fruits. The conclusions drawn so far with regard to the order of accumulation of heavy metals are: Roots>leaves>stalks>fruits ( edible parts) (ii) interactions between heavy metals, plant nutrients and soil chemical and physical properties. After the examinations of hundreds of interactions, and the development of a quantification of the interactions contribution, it was found that considerable quantities of heavy metals and nutrients are contributed to the soil and to various plant parts , emphasizing the important role of the elemental interactions in plants.(iii) assessment of soil pollution with heavy metals based on pollution indices, Three pollution Indices have been established by our research team and were proposed internationally for application in actual practice for the prediction of soil pollution due to long term reuse of wastewater and sludge. These indices are as follows: (a) Elemental pollution Index (EPI), (b) Heavy Metal Load (HML), and (c) Total Concentration Factor (TCF) and (iv) construction of a computer program for the control of the reuse of TMWW and sludge, and forecasting soil pollution due to accumulation of heavy metal by means of pollution indices.

Amyloid-carbon hybrid membranes for universal water purification

NASA Astrophysics Data System (ADS)

Bolisetty, Sreenath; Mezzenga, Raffaele

2016-04-01

Industrial development, energy production and mining have led to dramatically increased levels of environmental pollutants such as heavy metal ions, metal cyanides and nuclear waste. Current technologies for purifying contaminated waters are typically expensive and ion specific, and there is therefore a significant need for new approaches. Here, we report inexpensive hybrid membranes made from protein amyloid fibrils and activated porous carbon that can be used to remove heavy metal ions and radioactive waste from water. During filtration, the concentration of heavy metal ions drops by three to five orders of magnitude per passage and the process can be repeated numerous times. Notably, their efficiency remains unaltered when filtering several ions simultaneously. The performance of the membrane is enabled by the ability of the amyloids to selectively absorb heavy metal pollutants from solutions. We also show that our membranes can be used to recycle valuable heavy metal contaminants by thermally reducing ions trapped in saturated membranes, leading to the creation of elemental metal nanoparticles and films.

Study on the behavior of heavy metals during thermal treatment of municipal solid waste (MSW) components.

PubMed

Yu, Jie; Sun, Lushi; Wang, Ben; Qiao, Yu; Xiang, Jun; Hu, Song; Yao, Hong

2016-01-01

Laboratory experiments were conducted to investigate the volatilization behavior of heavy metals during pyrolysis and combustion of municipal solid waste (MSW) components at different heating rates and temperatures. The waste fractions comprised waste paper (Paper), disposable chopstick (DC), garbage bag (GB), PVC plastic (PVC), and waste tire (Tire). Generally, the release trend of heavy metals from all MSW fractions in rapid-heating combustion was superior to that in low-heating combustion. Due to the different characteristics of MSW fractions, the behavior of heavy metals varied. Cd exhibited higher volatility than the rest of heavy metals. For Paper, DC, and PVC, the vaporization of Cd can reach as high as 75% at 500 °C in the rapid-heating combustion due to violent combustion, whereas a gradual increase was observed for Tire and GB. Zn and Pb showed a moderate volatilization in rapid-heating combustion, but their volatilities were depressed in slow-heating combustion. During thermal treatment, the additives such as kaolin and calcium can react or adsorb Pb and Zn forming stable metal compounds, thus decreasing their volatilities. The formation of stable compounds can be strengthened in slow-heating combustion. The volatility of Cu was comparatively low in both high and slow-heating combustion partially due to the existence of Al, Si, or Fe in residuals. Generally, in the reducing atmosphere, the volatility of Cd, Pb, and Zn was accelerated for Paper, DC, GB, and Tire due to the formation of elemental metal vapor. TG analysis also showed the reduction of metal oxides by chars forming elemental metal vapor. Cu2S was the dominant Cu species in reducing atmosphere below 900 °C, which was responsible for the low volatility of Cu. The addition of PVC in wastes may enhance the release of heavy metals, while GB and Tire may play an opposite effect. In controlling heavy metal emission, aluminosilicate- and calcium-based sorbents can be co-treated with fuels. Moreover, pyrolysis can be a better choice for treatment of solid waster in terms of controlling heavy metals. PVC and Tire should be separated and treated individually due to high possibility of heavy metal emission. This information may then serve as a guideline for the design of the subsequent gas cleaning plant, necessary to reduce the final emissions to the atmosphere to an acceptable level.

(Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes

NASA Astrophysics Data System (ADS)

Thevenon, Florian; Guédron, Stéphane; Chiaradia, Massimo; Loizeau, Jean-Luc; Poté, John

2011-01-01

Continuous high-resolution sedimentary record of heavy metals (chromium (Cr), copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and mercury (Hg)), from lakes Lucerne and Meidsee (Switzerland), provides pollutant deposition history from two contrasting Alpine environments over the last millennia. The distribution of conservative elements (thorium (Th), scandium (Sc) and titanium (Ti)) shows that in absence of human disturbances, the trace element input is primarily controlled by weathering processes (i.e., runoff and erosion). Nonetheless, the enrichment factor (EF) of Pb and Hg (that are measured by independent methods), and the Pb isotopic composition of sediments from the remote lake Meidsee (which are proportionally more enriched in anthropogenic heavy metals), likely detect early mining activities during the Bronze Age. Meanwhile, the deposition of trace elements remains close to the range of natural variations until the strong impact of Roman activities on atmospheric metal emissions. Both sites display simultaneous increases in anthropogenic trace metal deposition during the Greek and Roman Empires (ca 300 BC to AD 400), the Late Middle Ages (ca AD 1400), and the Early Modern Europe (after ca AD 1600). However, the greatest increases in anthropogenic metal pollution are evidenced after the industrial revolution of ca AD 1850, at low and high altitudes. During the twentieth century, industrial releases multiplied by ca 10 times heavy metal fluxes to hydrological systems located on both sides of the Alps. During the last decades, the recent growing contribution of low radiogenic Pb further highlights the contribution of industrial sources with respect to wood and coal burning emissions.

The potential association between menta deformities and trace elements in Chironomidae (Diptera) taken from a heavy metal contaminated river.

PubMed

Martinez, E A; Moore, B C; Schaumloffel, J; Dasgupta, N

2002-04-01

Elevated morphological deformity rates in Chironomidae larvae have been attributed to such pollutants as oil tars, pesticides, organochlorines, and heavy metals. The potential of chironomids as biological indicators of heavy metal contamination and bioavailability in a contaminated ecosystem was assessed. Chironomid larvae and river sediment were collected from the Coeur d' Alene River system, Idaho, USA, contaminated with heavy metals from mining activities. Chironomid larvae collected at contaminated sites exhibited mouthpart deformity proportions between 3.8 and 10.3% compared to the control site of 0.9%. As, Cd, Cu, Ni, Pb, and Zn were determined in both larvae and sediment samples. Significant correlation between metal concentrations and deformity rates were observed for all metals except Ni. The data also suggests that feeding habits may influence differences in pollution tolerance among genera.

Element accumulation in boreal bryophytes, lichens and vascular plants exposed to heavy metal and sulfur deposition in Finland.

PubMed

Salemaa, Maija; Derome, John; Helmisaari, Heljä-Sisko; Nieminen, Tiina; Vanha-Majamaa, Ilkka

2004-05-25

Macronutrient (N, P, K, Mg, S, Ca), heavy metal (Fe, Zn, Mn, Cu, Ni, Cd, Pb) and Al concentrations in understorey bryophytes, lichens and vascular plant species growing in Scots pine forests at four distances from the Harjavalta Cu-Ni smelter (0.5, 2, 4 and 8 km) were compared to those at two background sites in Finland. The aim was to study the relationship between element accumulation and the distribution of the species along a pollution gradient. Elevated sulfur, nitrogen and heavy metal concentrations were found in all species groups near the pollution source. Macronutrient concentrations tended to decrease in the order: vascular plants>bryophytes>lichens, when all the species groups grew on the same plot. Heavy metal concentrations (except Mn) were the highest in bryophytes, followed by lichens, and were the lowest in vascular plants. In general, vascular plants, being capable of restricting the uptake of toxic elements, grew closer to the smelter than lichens, while bryophytes began to increase in the understorey vegetation at further distances from the smelter. A pioneer moss (Pohlia nutans) was an exception, because it accumulated considerably higher amounts of Cu and Ni than the other species and still survived close to the smelter. The abundance of most of the species decreased with increasing Cu and Ni concentrations in their tissues. Cetraria islandica, instead, showed a positive relationship between the abundance and Cu, Ni and S concentrations of the thallus. It is probable that, in addition to heavy metals, sporadically high SO(2) emissions have also affected the distribution of the plant species.

Will heavy metals in the soils of newly submerged areas threaten the water quality of Danjiangkou Reservoir, China?

PubMed

Song, Zhixin; Shan, Baoqing; Tang, Wenzhong; Zhang, Chao

2017-10-01

Soil heavy metal contents were measured in newly submerged areas of the Danjiangkou Reservoir, China. We aimed to determine the heavy metal distribution in this area and the associated ecological risk. Most of these heavy metal contents (except Pb and Mn) suggest enrichment compared with the background values of soils from Henan Province, especially As and Cd with mean geo-accumulation index (I geo ) values of 0.84 and 0.54. The spatial analysis results indicated that the highest heavy metal contents were distributed in the arable soils above 160m elevation, whereas low heavy metal contents were observed under other land-use types above 160m elevation. According to I geo and EF values, Cd was the major heavy metal contaminant in the newly submerged area, Cr, Pb and Mn mainly originated from natural geochemical sources. In contrast, Ni, Cd, As, Cu, and Zn mainly originated from anthropogenic sources. Evaluation using the potential ecological risk (PER) method indicated that PER of individual elements were low in the studied soils, and the comprehensive PER index was at a moderate level, indicating heavy metals in the soils of newly submerged areas may not threaten the water quality of Danjiangkou Reservoir, especially in winter. Copyright © 2017 Elsevier Inc. All rights reserved.

Heavy Metal Tolerance in Plants: Role of Transcriptomics, Proteomics, Metabolomics, and Ionomics

PubMed Central

Singh, Samiksha; Parihar, Parul; Singh, Rachana; Singh, Vijay P.; Prasad, Sheo M.

2016-01-01

Heavy metal contamination of soil and water causing toxicity/stress has become one important constraint to crop productivity and quality. This situation has further worsened by the increasing population growth and inherent food demand. It has been reported in several studies that counterbalancing toxicity due to heavy metal requires complex mechanisms at molecular, biochemical, physiological, cellular, tissue, and whole plant level, which might manifest in terms of improved crop productivity. Recent advances in various disciplines of biological sciences such as metabolomics, transcriptomics, proteomics, etc., have assisted in the characterization of metabolites, transcription factors, and stress-inducible proteins involved in heavy metal tolerance, which in turn can be utilized for generating heavy metal-tolerant crops. This review summarizes various tolerance strategies of plants under heavy metal toxicity covering the role of metabolites (metabolomics), trace elements (ionomics), transcription factors (transcriptomics), various stress-inducible proteins (proteomics) as well as the role of plant hormones. We also provide a glance of some strategies adopted by metal-accumulating plants, also known as “metallophytes.” PMID:26904030

Evaluation of hyperaccumulator plant species grown in metalliferous sites in Albania

NASA Astrophysics Data System (ADS)

Babani, F.; Civici, N.; Mullaj, A.; Kongjika, E.; Ylli, A.

2007-04-01

Heavy metal contamination of soils causes serious problems to our society. A small number of interesting plant species have been identified that can grow in soils containing high levels of heavy metals, and can also accumulate these metals to high concentrations in the shoot. The heavy metal contents in root, shoot, leaves and flowers of spontaneous plants grown in metalliferous sites in Albania together with the elemental composition of the native soils were determined by X-ray fluorescence spectrometry. Efficiency of photosynthetic apparatus of analyzed ecotypes was evaluated via chlorophyll fluorescence imaging during induction kinetics. Response of plant root system to the presence of metals, the available pools of metals to plants, effect of plant biomass to phytoextraction, photosynthetic pigment metabolism and chlorophyll fluorescence signature of leaves allowed to characterize hyperaccumulator properties and to detect the variation between selected ecotypes to heavy metal accumulation.

[Comparison of heavy metal elements between natural and plantation forests in a subtropical Montane forest].

PubMed

Nie, Ming; Wan, Jia-Rong; Chen, Xiao-Feng; Wang, Li; Li, Bo; Chen, Jia-Kuan

2011-11-01

Heavy metals as one of major pollutants is harmful to the health of forest ecosystems. In the present paper, the concentrations of thirteen heavy metals (Fe, Al, Ti, Cr, Cu, Mn, V, Zn, Ni, Co, Pb, Se and Cd) were compared between natural and plantation forests in the Mt. Lushan by ICP-AES and atomic absorption spectroscopy. The results suggest that the soil of natural forest had higher concentrations of Fe, Al, Ti, Cu, Mn, V, Zn, Ni, Co, Pb, Se, and Cd than the plantation forest except for Cr. The soil of natural forest had a higher level of heavy metals than that of the plantation forest as a whole. This might be due to that the natural forest has longer age than the plantation forest, and fixed soil heavy metals take a longer period of time than the plantation forest.

Heavy-metal pollution and potential ecological risk assessment of sediments from Baihua Lake, Guizhou, P.R. China.

PubMed

Huang, Xianfei; Hu, Jiwei; Li, Cunxiong; Deng, Jiajun; Long, Jian; Qin, Fanxin

2009-12-01

Baihua Lake, a man-made reservoir, is one of the five drinking water sources for Guiyang City in China's southwestern province of Guizhou. In the present research, the distribution and accumulation characteristics of heavy metals (Pb, Cd, As, Cu and Zn) for the sediment of this lake were analyzed by examination of 10 recently collected samples. A method based on toxic-response factor was applied to assess the potential ecological risk of these heavy metals to the water body. For comparison, the two sets of reference data representing the pre-industrial and the local baseline pollution levels were employed to derive the accumulating coefficients for the heavy metals under study. The calculated potential ecological risk indices show that the lake was polluted by heavy metals and both cadmium and arsenic loadings were critical factors responsible for the ecological hazards posed to Baihua Lake by the five elements.

Microwave-assisted digestion using nitric acid for heavy metals and sulfated ash testing in active pharmaceutical ingredients.

PubMed

Pluhácek, T; Hanzal, J; Hendrych, J; Milde, D

2016-04-01

The monitoring of inorganic impurities in active pharmaceutical ingredients plays a crucial role in the quality control of the pharmaceutical production. The heavy metals and residue on ignition/sulfated ash methods employing microwave-assisted digestion with concentrated nitric acid have been demonstrated as alternatives to inappropriate compendial methods recommended in United States Pharmacopoeia (USP) and European Pharmacopoeia (Ph. Eur.). The recoveries using the heavy metals method ranged between 89% and 122% for nearly all USP and Ph. Eur. restricted elements as well as the recoveries of sodium sulfate spikes were around 100% in all tested matrices. The proposed microwave-assisted digestion method allowed simultaneous decomposition of 15 different active pharmaceutical ingredients with sample weigh up to 1 g. The heavy metals and sulfated ash procedures were successfully applied to the determination of heavy metals and residue on ignition/sulfated ash content in mycophenolate mofetil, nicergoline and silymarin.

Distribution of heavy metals in agricultural soils near a petrochemical complex in Guangzhou, China.

PubMed

Li, Junhui; Lu, Ying; Yin, Wei; Gan, Haihua; Zhang, Chao; Deng, Xianglian; Lian, Jin

2009-06-01

The aim of the study was to investigate influence of an industrialized environment on the accumulation of heavy metals in agricultural soils. Seventy soil samples collected from surface layers (0-20 cm) and horizons of five selected pedons in the vicinity area of petrochemical complex in Guangzhou, China were analyzed for Zn, Cu, Pb, Cd, Hg and As concentrations, the horizontal and vertical variation of these metals were studied and geographic information system (GIS)-based mapping techniques were applied to generate spatial distribution maps. The mean concentrations of these heavy metals in the topsoils did not exceed the maximum allowable concentrations in agricultural soil of China with the exception of Hg. Significant differences between land-use types showed that Cu, Pb, Cd, Hg and As concentrations in topsoils were strongly influenced by agricultural practices and soil management. Within a radius of 1,300 m there were no marked decreasing trends for these element concentrations (except for Zn) with the increase of distance from the complex boundary, which reflected little influence of petroleum air emission on soil heavy metal accumulation. Concentrations of Zn, Cu, Pb, Cd, Hg and As in the five pedons, particularly in cultivated vegetable field and orchard, decreased with soil depth, indicating these elements mainly originated from anthropogenic sources. GIS mapping was a useful tool for evaluating spatial variability of heavy metals in the affected soil. The spatial distribution maps allowed the identification of hot-spot areas with high metal concentration. Effective measures should be taken to avoid or minimize heavy metal further contamination of soils and to remediate the contaminated areas in order to prevent pollutants affecting human health through agricultural products.

Recycling of spent adsorbents for oxyanions and heavy metal ions in the production of ceramics.

PubMed

Verbinnen, Bram; Block, Chantal; Van Caneghem, Jo; Vandecasteele, Carlo

2015-11-01

Spent adsorbents for oxyanion forming elements and heavy metals are classified as hazardous materials and they are typically treated by stabilization/solidification before landfilling. The use of lime or cement for stabilization/solidification entails a high environmental impact and landfilling costs are high. This paper shows that mixing spent adsorbents in the raw material for the production of ceramic materials is a valuable alternative to stabilize oxyanion forming elements and heavy metals. The produced ceramics can be used as construction material, avoiding the high economic and environmental impact of stabilization/solidification followed by landfilling. To study the stabilization of oxyanion forming elements and heavy metals during the production process, two series of experiments were performed. In the first series of experiments, the main pollutant, Mo was adsorbed onto iron-based adsorbents, which were then mixed with industrial sludge (3 w/w%) and heated at 1100°C for 30 min. Mo was chosen, as this element is easily adsorbed onto iron-based adsorbents and it is the element that is the most difficult to stabilize (i.e. the highest temperatures need to be reached before the concentrations in the leachate are reduced). Leaching concentration from the 97/3 sludge/adsorbent mixture before heating ranged between 85 and 154 mg/kg; after the heating process they were reduced to 0.42-1.48 mg/kg. Mo was actually stabilized, as the total Mo concentration after addition was not affected by the heat treatment. In the second series of experiments, the sludge was spiked with other heavy metals and oxyanion forming elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in concentrations 5 times higher than the initial concentrations; after heat treatment the leachate concentrations were below the regulatory limit values. The incorporation of spent adsorbents in ceramic materials is a valuable and sustainable alternative to the existing treatment methods, saving raw materials in the ceramics production process and avoiding the use of stabilizing agents. Besides, spent adsorbents added to the raw material for ceramic products, may improve their aesthetic and structural properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genes and quantitative trait loci (QTL) controlling trace element concentrations in perennial grasses grown on phytotoxic soil contaminated with heavy metals

USDA-ARS?s Scientific Manuscript database

Perennial grasses cover diverse soils throughout the world, including sites contaminated with heavy metals, producing forages that must be safe for livestock and wildlife. Chromosome regions known as quantitative trait loci (QTLs) controlling forage mineral concentrations were mapped in a populatio...

Dynamic analysis and vibration testing of CFRP drive-line system used in heavy-duty machine tool

NASA Astrophysics Data System (ADS)

Yang, Mo; Gui, Lin; Hu, Yefa; Ding, Guoping; Song, Chunsheng

2018-03-01

Low critical rotary speed and large vibration in the metal drive-line system of heavy-duty machine tool affect the machining precision seriously. Replacing metal drive-line with the CFRP drive-line can effectively solve this problem. Based on the composite laminated theory and the transfer matrix method (TMM), this paper puts forward a modified TMM to analyze dynamic characteristics of CFRP drive-line system. With this modified TMM, the CFRP drive-line of a heavy vertical miller is analyzed. And the finite element modal analysis model of the shafting is established. The results of the modified TMM and finite element analysis (FEA) show that the modified TMM can effectively predict the critical rotary speed of CFRP drive-line. And the critical rotary speed of CFRP drive-line is 20% higher than that of the original metal drive-line. Then, the vibration of the CFRP and the metal drive-line were tested. The test results show that application of the CFRP drive shaft in the drive-line can effectively reduce the vibration of the heavy-duty machine tool.

Soil quality changes in response to their pollution by heavy metals, Georgia.

PubMed

Matchavariani, Lia; Kalandadze, Besik; Lagidze, Lamzira; Gokhelashvili, Nino; Sulkhanishvili, Nino; Paichadze, Nino; Dvalashvili, Giorgi

2015-01-01

The present study deals with the composition, migration and accumulation of heavy metals in irrigated soils, plants and partially natural waters; and also, establishing the possible sources of pollution and their impact on environmental situation. The content of toxic elements in the irrigated soils adjacent to ore mining and processing enterprise were studied. Content of toxic elements in the irrigated soils adjacent to ore mining, showed that more than half of territory was seriously polluted by copper and zinc. Some part of the area were considered catastrophically polluted. Expressed technogenesis taking place influenced irrigation. Heavy metals like copper, zinc and manganese negative by effected the properties of soil, thus composition and soil-forming processes taking place in the soil. It was especially well represented in the deterioration of hydro-physical potential of the soil. Irrigation of agricultural land plots by water, polluted with heavy metals changed the pH. Balanced correlation among solid, liquid and gas phases was disrupted. In highly polluted soil, the cementing processes took place that sharply increased the bulk density of the soil, deteriorated the porosity of soil and reduced water permeability critically.

Concentration and distribution of heavy metals in two Andisols of the Azuay Andes (Ecuador)

NASA Astrophysics Data System (ADS)

Bech, Jaume; Roca, Núria; Ugalde, Sandra; Tonon, Luis; Larriva, Giovani

2013-04-01

At present many governmental and environmental bureaus are interested in establishing reliable soil quality criteria for heavy metals to enable the detection of polluted sites. To evaluate the variation of heavy metal natural concentration and to assess heavy metal contamination in soils, it is necessary to survey heavy metal baseline levels in order to understand their migration and distribution during pedogenesis. Many nationwide projects report elemental baseline values in soils. Baseline levels of heavy metals in soils have also been determined at local scales. Data is scarce on qualitative and quantitative trace elements content of Ecuatorian soils. The soils in the Azuay Andes (S of Ecuador) are thought to be generally non-contaminated. The objective of this study is to determine and evaluate the natural concentrations and distribution of seven heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) in Andisol of Azuay Andes. Soil samples were grounded in an agate mill prior to pseudototal heavy metal analysis. Cadmium, Co, Cr, Cu, Ni, Pb and Zn were determined by a masses spectrometer (MS-ICP) after aqua regia extraction according to ISO standard procedures. Soil particle size distribution, organic carbon, electrical conductivity and pH have been previously determined. Andisols are dominated by amorphous aluminium silicates and Al-organic complexes. The soils of volcanic area usually have an Ah-Bh-Bhs/Bw-C horizon sequence. The Ah horizon is dark-coloured and normally very high in organic matter, ranging from 6.4 to 15.2 %. A strong rise in pH upon addition of a fluoride solution is used to signal the presence of allophane. The pH usually rises to 10.5 bellow 20 cm. The range of total soil values in mgkg-1 is as follows: Cd (0.03-0.3), Co (0.8-5), Cr (7-15), Cu (9-25), Ni (2-4), Pb (11-41) and Zn (12-37). All heavy metal contents, except for Cd, are strongly correlated with pH. For the pseudototal fraction, there was significant difference between the soil horizons in regards to complex profile development.

Diversity of abundance patterns of neutron-capture elements in very metal-poor stars

NASA Astrophysics Data System (ADS)

Aoki, Misa; Aoki, Wako; Ishimaru, Yuhri; Wanajo, Shinya

2014-05-01

Observations of Very Metal-Poor stars indicate that there are at least two sites to r-process; "weak r-process" and "main r-process". A question is whether these two are well separated or there exists a variation in the r-process. We present the results of abundance analysis of neutron-capture elements in the two Very Metal-Poor stars HD107752 and HD110184 in the Milky Way halo observed with the Subaru Telescope HDS. The abundance patterns show overabundace at light n-capture elements (e.g. Sr, Y), inferring the element yielding of weak r-process, while heavy neutron-capture elements (e.g. Ba, Eu) are deficient; however, the overabundance of light ones is not as significant as that previously found in stars representing the weak r-process (e.g. HD122563; Honda et al. 2006). Our study show diversity in the abundance patterns from light to heavy neutron-capture elements in VMP stars, suggesting a variation in r-process, which may depend on electron fraction of environment.

Self-purification of agrosoddy-podzolic sandy loamy soils fertilized with sewage sludge

NASA Astrophysics Data System (ADS)

Plekhanova, I. O.

2017-04-01

Sandy loamy agrosoddy-podzolic soils and plants growing on them were studied. The soils had been treated with sewage sludge from the Lyubertsy aeration station applied as organic fertilizer for 5-10 years before 1990. Initially, these soils were used for cultivating vegetables and fodder crops. The content and mobility of heavy metal compounds increased in the plow horizons of studied soils under the influence of sewage sludge. The concentrations of Cd and Zn exceeded the tentative permissible concentrations (TPC) for these elements by 8-16 and 2-4 times, respectively. The contaminated layer was found at the depths within 30-50 cm, which attests to a low migration rate of heavy metals added to the studied soils with sewage sludge (SS) 25 years ago. The concentration of Cd exceeded the maximum permissible concentration (MPC) of this element in all vegetable and fodder crops cultivated on the studied soils. The content of heavy metals in plants differed by three-five times in dependence on the capacity of particular plants to accumulate them. The period of soil self-purification from heavy metals was found to depend on the soil contamination level and element mobility, as well as on the element removal with harvested crops and with soil water flows. The maximal time of achieving the normal level of Cd concentration was estimated as 288 years for maximally contaminated soils; the corresponding values for Cu and Zn were estimated as 74 and 64 years, respectively.

PRIMORDIAL r-PROCESS DISPERSION IN METAL-POOR GLOBULAR CLUSTERS

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

Roederer, Ian U., E-mail: iur@obs.carnegiescience.edu

Heavy elements, those produced by neutron-capture reactions, have traditionally shown no star-to-star dispersion in all but a handful of metal-poor globular clusters (GCs). Recent detections of low [Pb/Eu] ratios or upper limits in several metal-poor GCs indicate that the heavy elements in these GCs were produced exclusively by an r-process. Re-examining GC heavy element abundances from the literature, we find unmistakable correlations between the [La/Fe] and [Eu/Fe] ratios in four metal-poor GCs (M5, M15, M92, and NGC 3201), only two of which were known previously. This indicates that the total r-process abundances vary from star to star (by factors ofmore » 2-6) relative to Fe within each GC. We also identify potential dispersion in two other GCs (M3 and M13). Several GCs (M12, M80, and NGC 6752) show no evidence of r-process dispersion. The r-process dispersion is not correlated with the well-known light element dispersion, indicating that it was present in the gas throughout the duration of star formation. The observations available at present suggest that star-to-star r-process dispersion within metal-poor GCs may be a common but not ubiquitous phenomenon that is neither predicted by nor accounted for in current models of GC formation and evolution.« less

r-process enhanched metal-poor stars

NASA Astrophysics Data System (ADS)

Cowan, John; Sneden, Christopher; Lawler, James E.; Den Hartog, Elizabeth A.

Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy - the progenitors of the halo stars - responsible for neutron-capture synthesis of the heavy elements. The large star-to-star scatter observed in the abundances of neutron-capture element/iron ratios at low metallicities - which diminishes with in- creasing metallicity or [Fe/H] - suggests the formation of these heavy elements (presumably from certain types of supernovae) was rare in the early Galaxy. The stellar abundances also indicate a change from the r-process to the slow neutron capture (i.e., s-) process at higher metallicities in the Galaxy and provide insight into Galactic chemical evolution. Finally, the detection of thorium and uranium in halo and globular cluster stars offers an independent age-dating technique that can put lower limits on the age of the Galaxy, and hence the Universe.

Carbon based secondary compounds do not provide protection against heavy metal road pollutants in epiphytic macrolichens.

PubMed

Gauslaa, Yngvar; Yemets, Olena A; Asplund, Johan; Solhaug, Knut Asbjørn

2016-01-15

Lichens are useful monitoring organisms for heavy metal pollution. They are high in carbon based secondary compounds (CBSCs) among which some may chelate heavy metals and thus increase metal accumulation. This study quantifies CBSCs in four epiphytic lichens transplanted for 6months on stands along transects from a highway in southern Norway to search for relationships between concentrations of heavy metals and CBSCs along a gradient in heavy metal pollutants. Viability parameters and concentrations of 21 elements including nutrients and heavy metals in these lichen samples were reported in a separate paper. Medullary CBSCs in fruticose lichens (Ramalina farinacea, Usnea dasypoga) were reduced in the most polluted sites, but not in foliose ones (Parmelia sulcata, Lobaria pulmonaria), whereas cortical CBSC did not change with distance from the road in any species. Strong positive correlations only occurred between the major medullary compound stictic acid present in L. pulmonaria and most heavy metals, consistent with a chelating role of stictic acid, but not of other studied CBSCs or in other species. However, heavy metal chelating did not protect L. pulmonaria against damage because this species experienced the strongest reduction in viability in the polluted sites. CBSCs with an accumulation potential for heavy metals should be quantified in lichen biomonitoring studies of heavy metals because they, like stictic acid, could overshadow pollutant inputs in some species rendering biomonitoring data less useful. In the two fruticose lichen species, CBSCs decreased with increasing heavy metal concentration, probably because heavy metal exposure impaired secondary metabolism. Thus, we found no support for a heavy metal protection role of any CBSCs in studied epiphytic lichens. No intraspecific relationships occurred between CBSCs versus N or C/N-ratio. Interspecifically, medullary CBSCs decreased and cortical CBSCs increased with increasing C/N-ratio. Copyright © 2015 Elsevier B.V. All rights reserved.

Heavy Metal Concentrations in Soils and Factors Affecting Metal Uptake by Plants in the Vicinity of a Korean Cu-W Mine.

PubMed

Jung, Myung Chae

2008-04-04

Heavy metal concentrations were measured in soils and plants in and around a copper-tungsten mine in southeast Korea to investigate the influence of past base metal mining on the surface environment. The results of chemical analysis indicate that the heavy metals in soils decreased with distance from the source, controlled mainly by water movement and topography. The metal concentrations measured in plant species generally decreased in the order; spring onions > soybean leaves > perilla leaves » red pepper > corn grains » jujube grains, although this pattern varied moderately between different elements. The results agree with other reports that metal concentrations in leaves are usually much higher than those in grain. Factors influencing the bioavailability of metals and their occurrences in crops were found as soil pH, cation exchange capacity, organic matter content, soil texture, and interaction among the target elements. It is concluded that total metal concentrations in soils are the main controls on their contents in plants. Soil pH was also an important factor. A stepwise linear multiple regression analysis was also conducted to identify the dominant factors influencing metal uptake by plants. Metal concentrations in plants were also estimated by computer-aided statistical methods.

Determination of Trace Available Heavy Metals in Soil Using Laser-Induced Breakdown Spectroscopy Assisted with Phase Transformation Method.

PubMed

Yi, Rongxing; Yang, Xinyan; Zhou, Ran; Li, Jiaming; Yu, Huiwu; Hao, Zhongqi; Guo, Lianbo; Li, Xiangyou; Lu, Yongfeng; Zeng, Xiaoyan

2018-05-18

To detect available heavy metals in soil using laser-induced breakdown spectroscopy (LIBS) and improve its poor detection sensitivity, a simple and low cost sample pretreatment method named solid-liquid-solid transformation was proposed. By this method, available heavy metals were extracted from soil through ultrasonic vibration and centrifuging and then deposited on a glass slide. Utilization of this solid-liquid-solid transformation method, available Cd and Pb elements in soil were detected successfully. The results show that the regression coefficients of calibration curves for soil analyses reach to more than 0.98. The limits of detection could reach to 0.067 and 0.94 ppm for available Cd and Pb elements in soil under optimized conditions, respectively, which are much better than those obtained by conventional LIBS.

Trace-elements in sheep grazing near a lead-zinc smelting complex at Port Pirie, South Australia

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

Koh, T.S.; Judson, G.J.

1986-07-01

In South Australia, several studies have shown that heavy metal pollution of soils and plants occurs in the vicinity of a lead/zinc smelter at Port Pirie. Data on soil analysis indicates that at least 3400 km/sup 2/ of land near these smelters has been contaminated by the fallout of Pb, Zn and Cd. It is possible that contamination of soil and pasture by heavy metals may adversely affect the health of livestock grazing near the smelters. In sheep, Pb toxicity causes anorexia, abdominal pain and diarrhea while Zn or Cd supplementation reduces the Cu status. This study was undertaken tomore » investigate the effects of heavy metals on the trace-element status of sheep grazing at selected distances from the Port Pirie smelters.« less

Lauryl Amine as heavy metal collector of boiler ash from pulp and paper mill waste

NASA Astrophysics Data System (ADS)

Sembiring, M. P.; Kaban, J.; Bangun, N.; Saputra, E.

2018-04-01

Theincreasing of demand of pulp and paper products, will following with the growing the pulp and paper industryand generate significant mill waste. The total waste reached 1/3 of the amount raw materials used and ash boiler is the waste with the largest percentage of 52%. For that it takes effort to manage the existing waste. The boiler ash contained the chemical elements, it can be utilized such as fertilizer, because it also contains transition metals in form of heavy metal such as Cadmium (Cd), Cobalt (Co), Chrome (Cr), Cupprum (Cu), Ferrum (Fe), Nickel (Ni), and Zinc (Zn), the use of boiler ash must follow the threshold specified by the Government. Several studies have been undertaken to reduce and extract heavy metals from ash and sand of the boiler by using carbon dioxide as its ligand. Eelectrochemical method was used to remove and recovery of heavy metals from the incenerator. This study focused on removal of heavy metals using Lauryl Amine as collector and three solvents namely Dichloromethane, Ethanol and n-Hexane. The treatmentswas able to extract the heavy metal and generally reduce the heavy metal content of ash boiler pulp and paper mill waste. The combination treatment used toreduce the heavy metal content of 5 gram Lauryl Amine collector in Dichloromethane solvent for 4 hours process time.

Cadmium--influence on biochemical processes of the human organism.

PubMed

Boguszewska, Anna; Pasternak, Kazimierz

2004-01-01

Heavy metals are too well-known environmental pollutants of particularly dangerous effect to human health. Because of their wide usage in many industrial branches they are present everywhere in the air, water and soils. Food contamination by heavy elements is hard to avoid and it is a result of environmental contamination by dusts, industrial gases, sewage, waste and coal burning processes. One of the most harmful heavy metals, widely spread in nature is cadmium. Toxic cadmium action involves free oxygen generation and inactivation of protein containing cysteine residues with -SH groups. It influences many metabolic processes causing great damage in many organs. Cadmium can also interact with some essential elements leading to their homeostasis disorders.

[Environmental geochemical baseline of heavy metals in soils of the Ili river basin and pollution evaluation].

PubMed

Zhao, Xin-Ru; Nasier, Telajin; Cheng, Yong-Yi; Zhan, Jiang-Yu; Yang, Jian-Hong

2014-06-01

Environmental geochemical baseline models of Cu, Zn, Pb, As, Hg were established by standardized method in the ehernozem, chestnut soil, sierozem and saline soil from the Ili river valley region. The theoretical baseline values were calculated. Baseline factor pollution index evaluation method, environmental background value evaluation method and heavy metal cleanliness evaluation method were used to compare soil pollution degrees. The baseline factor pollution index evaluation showed that As pollution was the most prominent among the four typical types of soils within the river basin, with 7.14%, 9.76%, 7.50% of sampling points in chernozem, chestnut soil and sierozem reached the heavy pollution, respectively. 7.32% of sampling points of chestnut soil reached the permitted heavy metal Pb pollution index in the chestnut soil. The variation extent of As and Pb was the largest, indicating large human disturbance. Environmental background value evaluation showed that As was the main pollution element, followed by Cu, Zn and Pb. Heavy metal cleanliness evaluation showed that Cu, Zn and Pb were better than cleanliness level 2 and Hg was the of cleanliness level 1 in all four types of soils. As showed moderate pollution in sierozem, and it was of cleanliness level 2 or better in chernozem, chestnut soil and saline-alkali soil. Comparing the three evaluation systems, the baseline factor pollution index evaluation more comprehensively reflected the geochemical migration characteristics of elements and the soil formation processes, and the pollution assessment could be specific to the sampling points. The environmental background value evaluation neglected the natural migration of heavy metals and the deposition process in the soil since it was established on the regional background values. The main purpose of the heavy metal cleanliness evaluation was to evaluate the safety degree of soil environment.

Biogeochemistry of heavy metals in contaminated excessively moistened soils (Analytical review)

NASA Astrophysics Data System (ADS)

Vodyanitskii, Yu. N.; Plekhanova, I. O.

2014-03-01

The biogeochemical behavior of heavy metals in contaminated excessively moistened soils depends on the development of reducing conditions (either moderate or strong). Upon the moderate biogenic reduction, Cr as the metal with variable valence forms low-soluble compounds, which decreases its availability to plants and prevents its penetration into surface- and groundwater. Creation of artificial barriers for Cr fixation on contaminated sites is based on the stimulation of natural metal-reducing bacteria. Arsenic, being a metalloid with a variable valence, is mobilized upon the moderate biogenic reduction. The mobility of siderophilic heavy metals with a constant valence grows under the moderate reducing conditions at the expense of dissolution of iron (hydr)oxides as carriers of these metals. Zinc, which can enter the newly formed goethite lattice, is an exception. Strong reduction processes in organic excessively moist and flooded soils (usually enriched in S) lead to the formation of low-soluble sulfides of heavy elements with both variable (As) and constant (Cu, Ni, Zn, and Pb) valence. On changing aquatic regime in overmoistened soils and their drying, sulfides of heavy metals are oxidized, and previously fixed metals are mobilized.

Influence of heavy metal stress on antioxidant status and DNA damage in Urtica dioica.

PubMed

Gjorgieva, Darinka; Kadifkova Panovska, Tatjana; Ruskovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

2013-01-01

Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity.

Health risk assessment of heavy metals in soils and vegetables from wastewater irrigated area, Beijing-Tianjin city cluster, China.

PubMed

Wang, Yanchun; Qiao, Min; Liu, Yunxia; Zhu, Yongguan

2012-01-01

The possible health risks of heavy metals contamination to local population through food chain were evaluated in Beijing and Tianjin city cluster, China, where have a long history of sewage irrigation. The transfer factors (TF) for heavy metals from soil to vegetables for six elements including Cu, Zn, Pb, Cr, As and Cd were calculated and the pollution load indexes (PLI) were also assessed. Results indicate that only Cd exceeded the maximum acceptable limit in these sites. So far, the heavy metal concentrations in soils and vegetables were all below the permissible limits set by the Ministry of Environmental Protection of China and World Health Organization. The transfer factors of six heavy metals showed the trend as Cd > Zn > Cu > Pb > As > Cr, which were dependent on the vegetable species. The estimated dietary intakes of Cu, Zn, Pb, Cr, As and Cd were far below the tolerable limits and the target hazard quotient (THQ) values were less than 1, which suggested that the health risks of heavy metals exposure through consuming vegetables were generally assumed to be safe.

Contamination of Polish national parks with heavy metals.

PubMed

Staszewski, Tomasz; Łukasik, Włodzimierz; Kubiesa, Piotr

2012-07-01

The paper presents results of screening analysis of all Polish national parks (23) contamination with Cd, Cu, Pb and Zn on the basis of a three-level characteristic of heavy metal presence in Norway spruce stands: accumulation on the needle surface, concentration of heavy metals in spruce needles and concentration of bioavailable heavy metals in the soil. Based on the obtained results, the classification of forest ecosystem hazard in national parks with heavy metals was made using synthetic indicators. It was found out that Babiogórski, Magurski, Ojcowski and Gorczański National Parks, located in the southern part of the country, were the most polluted with heavy metals. It is probably due to a higher industrial activity in this part of Poland and the transboundary transport of air pollutants. A little lower level of pollution was observed in Kampinoski National Park located in the middle of the country. The concentration of heavy metals found in needles from national parks does not seem to be harmful for the health status of the trees. Statistically significant correlation between all parameters, which was found for cadmium--the most mobile of the analysed elements--shows that this metal can be proposed as a marker to reflect present effect of industrial emission on forests.

Labile rhizosphere soil solution fraction for prediction of bioavailability of heavy metals and rare earth elements to plants.

PubMed

Shan, Xiao-Quan; Wang, Zhongwen; Wang, Weisheng; Zhang, Shuzhen; Wen, Bei

2003-02-01

A labile rhizosphere soil solution fraction has been recommended to predict the bioavailability of heavy metals and rare earth elements to plants. This method used moist rhizosphere soil in combination with a mixture of 0.01 mol L(-1) of low-molecular-weight organic acids (LMWOAs) as extractant. The extracted soil solutions were fractionated into two colloidal fractions of <0.45 microm (F(3)) and <0.2 microm (F(2)), and one truly dissolved fraction including free metal ions and inorganic and organic complexes (fractionr(0.2 microm, LMWOAs) approximately r(0.45 microm, LMWOAs). In the case of rare earth elements the good correlation was obtained for both the wheat roots and shoots. Generally, the correlation coefficients obtained by LMWAOs were better than that obtained by the first step of BCR method. Therefore, LMWAOs and F(lrss) were strongly recommended to predict the bioavailability of metals in soil pools to plants.

The Ubiquity of the Rapid Neutron-capture Process

NASA Astrophysics Data System (ADS)

Roederer, Ian U.; Cowan, John J.; Karakas, Amanda I.; Kratz, Karl-Ludwig; Lugaro, Maria; Simmerer, Jennifer; Farouqi, Khalil; Sneden, Christopher

2010-12-01

To better characterize the abundance patterns produced by the r-process, we have derived new abundances or upper limits for the heavy elements zinc (Zn, Z= 30), yttrium (Y, Z= 39), lanthanum (La, Z= 57), europium (Eu, Z= 63), and lead (Pb, Z= 82). Our sample of 161 metal-poor stars includes new measurements from 88 high-resolution and high signal-to-noise spectra obtained with the Tull Spectrograph on the 2.7 m Smith Telescope at the McDonald Observatory, and other abundances are adopted from the literature. We use models of the s-process in asymptotic giant branch stars to characterize the high Pb/Eu ratios produced in the s-process at low metallicity, and our new observations then allow us to identify a sample of stars with no detectable s-process material. In these stars, we find no significant increase in the Pb/Eu ratios with increasing metallicity. This suggests that s-process material was not widely dispersed until the overall Galactic metallicity grew considerably, perhaps even as high as [Fe/H] =-1.4, in contrast with earlier studies that suggested a much lower mean metallicity. We identify a dispersion of at least 0.5 dex in [La/Eu] in metal-poor stars with [Eu/Fe] <+0.6 attributable to the r-process, suggesting that there is no unique "pure" r-process elemental ratio among pairs of rare earth elements. We confirm earlier detections of an anti-correlation between Y/Eu and Eu/Fe bookended by stars strongly enriched in the r-process (e.g., CS 22892-052) and those with deficiencies of the heavy elements (e.g., HD 122563). We can reproduce the range of Y/Eu ratios using simulations of high-entropy neutrino winds of core-collapse supernovae that include charged-particle and neutron-capture components of r-process nucleosynthesis. The heavy element abundance patterns in most metal-poor stars do not resemble that of CS 22892-052, but the presence of heavy elements such as Ba in nearly all metal-poor stars without s-process enrichment suggests that the r-process is a common phenomenon. This paper includes data taken at The McDonald Observatory of The University of Texas at Austin.

[History of heavy metal pollution from tidal flat in Haizhou Bay].

PubMed

Zhang, Rui; Zhang, Fan; Liu, Fu-Cheng; Yin, Fu-Jun; Ding, Ying-Jun; Gao, Jin-Rong; Chen, Jing; Shao, Wei

2013-03-01

Coastal zone could be considered as an important sink of regional source to sink and preserve historical records of environmental evolution. Four sediment cores, collected from tidal flat at Haizhou Bay near Lianyungang City, were examined for concentrations of heavy metals including Cd, Cr, Cu, Mn, Pb and Zn in core sediments to investigate the historical input of trace metals. In addition, sediment rates of cores LH3 and LH4 were determined based on radionuclide 210Pb. The results showed that grain size control effect was not the main factor that influenced the distribution of heavy metals. Heavy metals concentrations in the surface sediments were higher than these regional background values. Furthermore, Al element as a proxy of grain size was selected for normalization and calculation of metal enrichment factor (EF) and anthropogenic heavy metal fluxes. The results revealed that heavy metals in tidal flats were continuously enriched in the past decades, meanwhile, tidal flats have been significantly subjected to contaminations due to anthropogenic activities. Moreover, the depth profiles of heavy metals fluxes correspond to scenario of social-economy development of Lianyungang, which is an important urban area near Haizhou Bay. From 1950s to 2005, anthropogenic fluxes of metals increased with fluctuations, whereas, since 2005 anthropogenic fluxes declined, which may be correlated to the adjustment of industrial structure as well as the strengthened environmental regulation.

Review: Nutritional ecology of heavy metals.

PubMed

Hejna, M; Gottardo, D; Baldi, A; Dell'Orto, V; Cheli, F; Zaninelli, M; Rossi, L

2018-01-08

The aim of this review is to focus the attention on the nutrition ecology of the heavy metals and on the major criticisms related to the heavy metals content in animal feeds, manure, soil and animal-origin products. Heavy metals are metallic elements that have a high density that have progressively accumulated in the food chain with negative effects for human health. Some metals are essential (Fe, I, Co, Zn, Cu, Mn, Mo, Se) to maintain various physiological functions and are usually added as nutritional additives in animal feed. Other metals (As, Cd, F, Pb, Hg) have no established biological functions and are considered as contaminants/undesirable substances. The European Union adopted several measures in order to control their presence in the environment, as a result of human activities such as: farming, industry or food processing and storage contamination. The control of the animal input could be an effective strategy to reduce human health risks related to the consumption of animal-origin products and the environmental pollution by manure. Different management of raw materials and feed, animal species as well as different legal limits can influence the spread of heavy metals. To set up effective strategies against heavy metals the complex interrelationships in rural processes, the widely variability of farming practices, the soil and climatic conditions must be considered. Innovative and sustainable approaches have discussed for the heavy metal nutrition ecology to control the environmental pollution from livestock-related activities.

Environmental assessment of Al-Hammar Marsh, Southern Iraq.

PubMed

Al-Gburi, Hind Fadhil Abdullah; Al-Tawash, Balsam Salim; Al-Lafta, Hadi Salim

2017-02-01

(a) To determine the spatial distributions and levels of major and minor elements, as well as heavy metals, in water, sediment, and biota (plant and fish) in Al-Hammar Marsh, southern Iraq, and ultimately to supply more comprehensive information for policy-makers to manage the contaminants input into the marsh so that their concentrations do not reach toxic levels. (b) to characterize the seasonal changes in the marsh surface water quality. (c) to address the potential environmental risk of these elements by comparison with the historical levels and global quality guidelines (i.e., World Health Organization (WHO) standard limits). (d) to define the sources of these elements (i.e., natural and/or anthropogenic) using combined multivariate statistical techniques such as Principal Component Analysis (PCA) and Agglomerative Hierarchical Cluster Analysis (AHCA) along with pollution analysis (i.e., enrichment factor analysis). Water, sediment, plant, and fish samples were collected from the marsh, and analyzed for major and minor ions, as well as heavy metals, and then compared to historical levels and global quality guidelines (WHO guidelines). Then, multivariate statistical techniques, such as PCA and AHCA, were used to determine the element sourcing. Water analyses revealed unacceptable values for almost all physio-chemical and biological properties, according to WHO standard limits for drinking water. Almost all major ions and heavy metal concentrations in water showed a distinct decreasing trend at the marsh outlet station compared to other stations. In general, major and minor ions, as well as heavy metals exhibit higher concentrations in winter than in summer. Sediment analyses using multivariate statistical techniques revealed that Mg, Fe, S, P, V, Zn, As, Se, Mo, Co, Ni, Cu, Sr, Br, Cd, Ca, N, Mn, Cr, and Pb were derived from anthropogenic sources, while Al, Si, Ti, K, and Zr were primarily derived from natural sources. Enrichment factor analysis gave results compatible with multivariate statistical techniques findings. Analysis of heavy metals in plant samples revealed that there is no pollution in plants in Al-Hammar Marsh. However, the concentrations of heavy metals in fish samples showed that all samples were contaminated by Pb, Mn, and Ni, while some samples were contaminated by Pb, Mn, and Ni. Decreasing of Tigris and Euphrates discharges during the past decades due to drought conditions and upstream damming, as well as the increasing stress of wastewater effluents from anthropogenic activities, led to degradation of the downstream Al-Hammar Marsh water quality in terms of physical, chemical, and biological properties. As such properties were found to consistently exceed the historical and global quality objectives. However, element concentration decreasing trend at the marsh outlet station compared to other stations indicate that the marsh plays an important role as a natural filtration and bioremediation system. Higher element concentrations in winter were due to runoff from the washing of the surrounding Sabkha during flooding by winter rainstorms. Finally, the high concentrations of heavy metals in fish samples can be attributed to bioaccumulation and biomagnification processes.

Divergent biology of facultative heavy metal plants.

PubMed

Bothe, Hermann; Słomka, Aneta

2017-12-01

Among heavy metal plants (the metallophytes), facultative species can live both in soils contaminated by an excess of heavy metals and in non-affected sites. In contrast, obligate metallophytes are restricted to polluted areas. Metallophytes offer a fascinating biology, due to the fact that species have developed different strategies to cope with the adverse conditions of heavy metal soils. The literature distinguishes between hyperaccumulating, accumulating, tolerant and excluding metallophytes, but the borderline between these categories is blurred. Due to the fact that heavy metal soils are dry, nutrient limited and are not uniform but have a patchy distribution in many instances, drought-tolerant or low nutrient demanding species are often regarded as metallophytes in the literature. In only a few cases, the concentrations of heavy metals in soils are so toxic that only a few specifically adapted plants, the genuine metallophytes, can cope with these adverse soil conditions. Current molecular biological studies focus on the genetically amenable and hyperaccumulating Arabidopsis halleri and Noccaea (Thlaspi) caerulescens of the Brassicaceae. Armeria maritima ssp. halleri utilizes glands for the excretion of heavy metals and is, therefore, a heavy metal excluder. The two endemic zinc violets of Western Europe, Viola lutea ssp. calaminaria of the Aachen-Liège area and Viola lutea ssp. westfalica of the Pb-Cu-ditch of Blankenrode, Eastern Westphalia, as well as Viola tricolor ecotypes of Eastern Europe, keep their cells free of excess heavy metals by arbuscular mycorrhizal fungi which bind heavy metals. The Caryophyllaceae, Silene vulgaris f. humilis and Minuartia verna, apparently discard leaves when overloaded with heavy metals. All Central European metallophytes have close relatives that grow in areas outside of heavy metal soils, mainly in the Alps, and have, therefore, been considered as relicts of the glacial epoch in the past. However, the current literature favours the idea that hyperaccumulation of heavy metals serves plants as deterrent against attack by feeding animals (termed elemental defense hypothesis). The capability to hyperaccumulate heavy metals in A. halleri and N. caerulescens is achieved by duplications and alterations of the cis-regulatory properties of genes coding for heavy metal transporting/excreting proteins. Several metallophytes have developed ecotypes with a varying content of such heavy metal transporters as an adaption to the specific toxicity of a heavy metal site. Copyright © 2017 Elsevier GmbH. All rights reserved.

Multivariate statistical and lead isotopic analyses approach to identify heavy metal sources in topsoil from the industrial zone of Beijing Capital Iron and Steel Factory.

PubMed

Zhu, Guangxu; Guo, Qingjun; Xiao, Huayun; Chen, Tongbin; Yang, Jun

2017-06-01

Heavy metals are considered toxic to humans and ecosystems. In the present study, heavy metal concentration in soil was investigated using the single pollution index (PIi), the integrated Nemerow pollution index (PIN), and the geoaccumulation index (Igeo) to determine metal accumulation and its pollution status at the abandoned site of the Capital Iron and Steel Factory in Beijing and its surrounding area. Multivariate statistical (principal component analysis and correlation analysis), geostatistical analysis (ArcGIS tool), combined with stable Pb isotopic ratios, were applied to explore the characteristics of heavy metal pollution and the possible sources of pollutants. The results indicated that heavy metal elements show different degrees of accumulation in the study area, the observed trend of the enrichment factors, and the geoaccumulation index was Hg > Cd > Zn > Cr > Pb > Cu ≈ As > Ni. Hg, Cd, Zn, and Cr were the dominant elements that influenced soil quality in the study area. The Nemerow index method indicated that all of the heavy metals caused serious pollution except Ni. Multivariate statistical analysis indicated that Cd, Zn, Cu, and Pb show obvious correlation and have higher loads on the same principal component, suggesting that they had the same sources, which are related to industrial activities and vehicle emissions. The spatial distribution maps based on ordinary kriging showed that high concentrations of heavy metals were located in the local factory area and in the southeast-northwest part of the study region, corresponding with the predominant wind directions. Analyses of lead isotopes confirmed that Pb in the study soils is predominantly derived from three Pb sources: dust generated during steel production, coal combustion, and the natural background. Moreover, the ternary mixture model based on lead isotope analysis indicates that lead in the study soils originates mainly from anthropogenic sources, which contribute much more than the natural sources. Our study could not only reveal the overall situation of heavy metal contamination, but also identify the specific pollution sources.

Use of Carboxymethyl-beta-cyclodextrin (CMCD) as Flushing Agent for Remediation of Metal Contaminated Soil

NASA Astrophysics Data System (ADS)

Skold, M. E.; Thyne, G. D.; McCray, J. E.; Drexler, J. W.

2005-12-01

One of the major challenges in remediating soil and ground water is the presence of mixed organic and inorganic contaminants. Due to their very different behavior, research has to a large extent focused on remediation of either organic or inorganic contaminants rather than mixed waste. Cyclodextrins (CDs) are a group of non-toxic sugar based molecules that do not sorb to soil particles and do not experience pore size exclusion. Thus, they have good hydraulic properties. CDs enhance the solubility of organic compounds by forming inclusion complexes between organic contaminants and the non-polar cavity at the center of the CD. By substituting functional groups to the cyclodextrin molecule it can form complexes with heavy metals. Previous studies have shown that carboxymethyl-beta-cyclodextrin (CMCD) can simultaneously complex organic and inorganic contaminants. The aim of this study is to compare how strongly CMCD complexes several common heavy metals, radioactive elements and a common divalent cation. Results from batch experiments show that CMCD has the ability to complex a wide array of heavy metals and radioactive elements. The solubility of metal oxalates and metal oxides clearly increased in the presence of CMCD. Logarithmic conditional formation constants ranged from 3.5 to 6 for heavy metals and from 3 to 6 for radioactive elements. Calcium, which may compete for binding sites, has a logarithmic conditional formation constant of 3.1. Batch experiments performed at 10 and 25 degrees C showed little temperature effect on conditional formation constants. Results from batch experiments were compared to results from column experiments where Pb was sorbed onto hydrous ferric oxide coated sand and subsequently removed by a CMCD solution. The results indicate that CMCD is a potential flushing agent for remediation of mixed waste sites.

Granulometric selectivity in Liza ramado and potential contamination resulting from heavy metal load in feeding areas

NASA Astrophysics Data System (ADS)

Pedro, Sílvia; Canastreiro, Vera; Caçador, Isabel; Pereira, Eduarda; Duarte, Armando C.; Raposo de Almeida, Pedro

2008-11-01

The stomach contents of thin-lipped grey mullets Liza ramado were analysed in terms of granulometric composition and compared to the sediment of potential feeding areas in the Tagus estuary. Total organic matter (TOM) content and heavy metal content were determined in the surface sediment of three areas and eight trace elements were quantified: Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. The three sampled areas did not differ in TOM; and the heavy metal content was below Effects Range-Low level for most elements. The mean observed concentrations were present in the following sequence: Zn > Pb > Cr > Cu ≈ Ni > Co > Cd > Hg. Stomach contents granulometric composition provided information about the feeding selectivity of the mullets. Sediment fractions with particle size between 20 and 50 μm are preferred, independently of the fishes' length. Smaller standard length (SL) fishes have a higher positive selection of fine grained sediments than those with a larger SL. Finer fractions usually have higher concentration of heavy metals, which makes younger specimens of the thin-lipped grey mullet potentially more exposed to heavy metal load in the estuary. Metal concentration was not independent from the sampling point, presenting higher values near the margins and the estuary tidal drainage system. This means that during the first period of each tidal cycle, the mullets will feed first on the most contaminated areas, as a consequence of their movement following the rising tide to feed on previously exposed areas.

Ten Thousand Years of Environment Assessment Using Synchrotron Radiation Micro Beam

NASA Astrophysics Data System (ADS)

Shirasawa, K.; Ide-Ektessabi, A.; Koizumi, A.; Azechi, M.

2003-08-01

The environment surrounding human has changed through civilization and industrialization, and through these developments, problems including the pollution from heavy metals such as lead and mercury have arisen. In this study, we analyzed major and trace elements in modern and prehistoric teeth by x-ray fluorescence (XRF) analysis using synchrotron radiation micro beam, in order to assess the changes of the environment through the civilization and the industrialization and their affects to the human. It is suggested that teeth accumulate elements in the mineral phase, hydroxiapatite, during their formation, and because there are no significant turnovers, teeth are concerned to be indicators of the environment of the donor. We first analyzed the elements on the surface of tooth from modern individual and tooth from human remains of Jomon period to assess the heavy metal concentration and effect of the diagenesis. The adhering ground elements on the prehistoric teeth showed high amount of Ti, Fe, Mn and other metallic elements.

Assessment of heavy metals in Averrhoa bilimbi and A. carambola fruit samples at two developmental stages.

PubMed

Soumya, S L; Nair, Bindu R

2016-05-01

Though the fruits of Averrhoa bilimbi and A. carambola are economically and medicinally important, they remain underutilized. The present study reports heavy metal quantitation in the fruit samples of A. bilimbi and A. carambola (Oxalidaceae), collected at two stages of maturity. Heavy metals are known to interfere with the functioning of vital cellular components. Although toxic, some elements are considered essential for human health, in trace quantities. Heavy metals such as Cr, Mn, Co, Cu, Zn, As, Se, Pb, and Cd were analyzed by atomic absorption spectroscopy (AAS). The samples under investigation included, A. bilimbi unripe (BU) and ripe (BR), A. carambola sour unripe (CSU) and ripe (CSR), and A. carambola sweet unripe (CTU) and ripe (CTR). Heavy metal analysis showed that relatively higher level of heavy metals was present in BR samples compared to the rest of the samples. The highest amount of As and Se were recorded in BU samples while Mn content was highest in CSU samples and Co in CSR. Least amounts of Cr, Zn, Se, Cd, and Pb were noted in CTU while, Mn, Cu, and As were least in CTR. Thus, the sweet types of A. carambola (CTU, CTR) had comparatively lower heavy metal content. There appears to be no reason for concern since different fruit samples of Averrhoa studied presently showed the presence of various heavy metals in trace quantities.

Enhanced heavy metal immobilization in soil by grinding with addition of nanometallic Ca/CaO dispersion mixture.

PubMed

Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Kakeda, Mitsunori

2012-10-01

This study investigated the use of a nanometallic Ca and CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb) in contaminated soil. Simple grinding achieved 85-90% heavy metal immobilization, but it can be enhanced further to 98-100% by addition of a nanometallic Ca/CaO dispersion mixture produced by grinding. Observations using SEM-EDS elemental maps and semi-quantitative analysis showed that the amounts of As, Cd, Cr, and Pb measurable on the soil particle surface decrease after nanometallic Ca/CaO treatment. The leachable heavy metal concentrations were reduced after nanometallic Ca/CaO treatment to concentrations lower than the Japan soil elution standard regulatory threshold: <0.01 mg L(-1) for As, Cd, and Pb; and 0.05 mg L(-1) for Cr. Effects of soil moisture and pH on heavy metal immobilization were not strongly influenced. The most probable mechanisms for the enhancement of heavy metal immobilization capacity with nanometallic Ca/CaO treatment might be due to adsorption and entrapment of heavy metals into newly formed aggregates, thereby prompting aggregation of soil particles and enclosure/binding with Ca/CaO-associated immobile salts. Results suggest that the nanometallic Ca/CaO mixture is suitable for use in immobilization of heavy-metal-contaminated soil under normal moisture conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Distribution of Heavy Metals in Surface Sediments of the Bay of Bengal Coast

PubMed Central

Hasan, M. R.; Khan, M.; Aktar, S.; Fatema, K.

2017-01-01

The concentrations of major (Si, Al, Ca, Fe, and K) and minor (Cd, Mn, Ni, Pb, U, Zn, Co, Cr, As, Cu, Rb, Sr, and Zr,) elements in the surficial sediments were studied in an attempt to establish their concentration in the Bengal coast. It was revealed that the majority of the trace elements have been introduced into the Bengal marine from the riverine inflows that are also affected by the impact of industrial, ship breaking yard, gas production plant, and urban wastes. The concentration of heavy metals was measured using Atomic Absorption Spectroscopy and Energy Dispersive X-ray fluorescence instruments. The highest concentrations for several trace elements were thus recorded which generally decrease with distance from the coast. It was observed that the heavy metal concentrations in the sediments generally met the criteria of international marine sediment quality. However, both the contamination factor and pollution load index values suggested the elevation of some metals' concentrations in the region. Constant monitoring of the Bengal coast water quality needs to be recorded with a view to minimizing the risk of health of the population and the detrimental impacts on the aquatic ecosystem. PMID:28255298

[Determination of Heavy Metal Elements in Diatomite Filter Aid by Inductively Coupled Plasma Mass Spectrometry].

PubMed

Nie, Xi-du; Fu, Liang

2015-11-01

This study established a method for determining Be, Cr, Ni, As, Cd, Sb, Sn, Tl, Hg and Pb, total 10 heavy metals in diatomite filter aid. The diatomite filter aid was digested by using the mixture acid of HNO₃ + HF+ H₃PO₄ in microwave system, 10 heavy metals elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The interferences of mass spectrometry caused by the high silicon substrate were optimized, first the equipment parameters and isotopes of test metals were selected to eliminate these interferences, the methane was selected as reactant gas, and the mass spectral interferences were eliminated by dynamic reaction cell (DRC). Li, Sc, Y, In and Bi were selected as the internal standard elements to correct the interferences caused by matrix and the drift of sensitivity. The results show that the detection limits for analyte is in the range of 3.29-15.68 ng · L⁻¹, relative standard deviations (RSD) is less than 4.62%, and the recovery is in the range of 90.71%-107.22%. The current method has some advantages such as, high sensitivity, accurate, and precision, which can be used in diatomite filter aid quality control and safety estimations.

Heavy metals in wild rice from northern Wisconsin

USGS Publications Warehouse

Bennett, J.P.; Chiriboga, E.; Coleman, J.; Waller, D.M.

2000-01-01

Wild rice grain samples from various parts of the world have been found to have elevated concentrations of heavy metals, raising concern for potential effects on human health. It was hypothesized that wild rice from north-central Wisconsin could potentially have elevated concentrations of some heavy metals because of possible exposure to these elements from the atmosphere or from water and sediments. In addition, no studies of heavy metals in wild rice from Wisconsin had been performed, and a baseline study was needed for future comparisons. Wild rice plants were collected from four areas in Bayfield, Forest, Langlade, Oneida, Sawyer and Wood Counties in September, 1997 and 1998 and divided into four plant parts for elemental analyses: roots, stems, leaves and seeds. A total of 194 samples from 51 plants were analyzed across the localities, with an average of 49 samples per part depending on the element. Samples were cleaned of soil, wet digested, and analyzed by ICP for Ag, As, Cd, Cr, Cu, Hg, Mg, Pb, Se and Zn. Roots contained the highest concentrations of Ag, As, Cd, Cr, Hg, Pb, and Se. Copper was highest in both roots and seeds, while Zn was highest just in seeds. Magnesium was highest in leaves. Seed baseline ranges for the 10 elements were established using the 95% confidence intervals of the medians. Wild rice plants from northern Wisconsin had normal levels of the nutritional elements Cu, Mg and Zn in the seeds. Silver, Cd, Hg, Cr, and Se were very low in concentration or within normal limits for food plants. Arsenic and Pb, however, were elevated and could pose a problem for human health. The pathway for As, Hg and Pb to the plants could be atmospheric.

Using expansive grasses for monitoring heavy metal pollution in the vicinity of roads.

PubMed

Vachová, Pavla; Vach, Marek; Najnarová, Eva

2017-10-01

We propose a method for monitoring heavy metal deposition in the vicinity of roads using the leaf surfaces of two expansive grass species which are greatly abundant. A principle of the proposed procedure is to minimize the number of operations in collecting and preparing samples for analysis. The monitored elements are extracted from the leaf surfaces using dilute nitric acid directly in the sample-collection bottle. The ensuing steps, then, are only to filter the extraction solution and the elemental analysis itself. The verification results indicate that the selected grasses Calamagrostis epigejos and Arrhenatherum elatius are well suited to the proposed procedure. Selected heavy metals (Zn, Cu, Pb, Ni, Cr, and Cd) in concentrations appropriate for direct determination using methods of elemental analysis can be extracted from the surface of leaves of these species collected in the vicinity of roads with medium traffic loads. Comparing the two species showed that each had a different relationship between the amounts of deposited heavy metals and distance from the road. This disparity can be explained by specific morphological properties of the two species' leaf surfaces. Due to the abundant occurrence of the two species and the method's general simplicity and ready availability, we regard the proposed approach to constitute a broadly usable and repeatable one for producing reproducible results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phytoextraction and phytostabilization potential of plants grown in the vicinity of heavy metal-contaminated soils: a case study at an industrial town site.

PubMed

Lorestani, B; Yousefi, N; Cheraghi, M; Farmany, A

2013-12-01

With the development of urbanization and industrialization, soils have become increasingly polluted by heavy metals. Phytoremediation, an emerging cost-effective, nonintrusive, and aesthetically pleasing technology that uses the remarkable ability of plants to concentrate elements, can be potentially used to remediate metal-contaminated sites. In this research, two processes of phytoremediation (phytoextraction and phytostabilization) were surveyed in some plant species around an industrial town in the Hamedan Province in the central-western part of Iran. To this purpose, shoots and roots of the seven plant species and the associated soil samples were collected and analyzed by measuring Pb, Fe, Mn, Cu, and Zn concentrations using ICP-AES and then calculating the biological absorption coefficient, bioconcentration factor, and translocation factor parameters for each element. The obtained results showed that among the collected plants, Salsola soda is the most effective species for phytoextraction and phytostabilization and Cirsium arvense has the potential for phytostabilization of the measured heavy metals.

Seasonal variations in the heavy metal concentrations of sediments influenced by highways of different traffic volumes

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

Van Hassel, J.H.; Ney, J.J.; Garling, D.L.

1979-11-01

The distribution of contaminating waste products, particularly heavy metals, to the roadside ecosystem is cause for considerable concern, due to both the documented toxicity of these metals at low concentrations and their accumulation by resident organisms. The elements of major concern are lead from gasoline engine exhsuts, nickel from both diesel fuel and lubricating oil, and cadmium and zinc from rubber tires. Lead has been correlated to traffic density in various components of the terrestrial ecosystem. Similar results were reported for nickel, cadmium, and zinc, as well as lead. Information concerning concentration of heavy metals in roadside aquatic ecosystems ismore » very limited. To provide an initial assessment of contamination from this source, we determined seasonal concentrations of heavy metals in stream sediment as related to traffic density. Heavy metals entering the stream ecosystem in runoff are rapidly adsorbed to sediment, providing a stable indicator of local contamination. Analysis of seasonal change in the heavy metal load of the sediment provides insight concerning the importance of runoff relative to sediment-water interaction and uptake by other componenets of the system.« less

Trace elements and heavy metals in hair of stage III breast cancer patients.

PubMed

Benderli Cihan, Yasemin; Sözen, Selim; Oztürk Yıldırım, Sema

2011-12-01

This prospective study was designed to compare the hair levels of 36 elements in 52 patients with stage III breast cancer to those of an equal number of healthy individuals. Principal component and cluster analysis were used for source of identification and apportionment of heavy metals and trace elements in these two groups. A higher average level of iron was found in samples from patients while controls had higher levels of calcium. Both patients and controls had elevated levels of tin, magnesium, zinc, and sodium. Almost all element values in cancer patients showed higher dispersion and asymmetry than in healthy controls. Between the two groups, there were statistically significant differences in the concentrations of silver, arsenic, gold, boron, barium, beryllium, calcium, cadmium, cerium, cobalt, cesium, gadolinium, manganese, nickel, lead, antimony, scandium, selenium, and zinc (p < 0.05). Strong positive correlations were found between lead and gold (r = 0.785) in the cancer group and between palladium and cobalt (r = 0.945) in the healthy individuals. Our results show that there are distinct patterns of heavy metals and trace elements in the hair of breast cancer patients in comparison to healthy controls. These results could be of significance in the diagnosis of breast cancer.

Heavy metals contamination and their risk assessment around the abandoned base metals and Au-Ag mines in Korea

NASA Astrophysics Data System (ADS)

Chon, Hyo-Taek

2017-04-01

Heavy metals contamination in the areas of abandoned Au-Ag and base metal mines in Korea was investigated in order to assess the level of metal pollution, and to draw general summaries about the fate of toxic heavy metals in different environments. Efforts have been made to compare the level of heavy metals, chemical forms, and plant uptake of heavy metals in each mine site. In the base-metals mine areas, significant levels of Cd, Cu, Pb and Zn were found in mine dump soils developed over mine waste materials and tailings. Leafy vegetables tend to accumulate heavy metals(in particular, Cd and Zn) higher than other crop plants, and high metal concentrations in rice crops may affect the local residents' health. In the Au-Ag mining areas, arsenic would be the most characteristic contaminant in the nearby environment. Arsenic and heavy metals were found to be mainly associated with sulfide gangue minerals, and the mobility of these metals would be enhanced by the effect of continuing weathering and oxidation. According to the sequential extraction of metals in soils, most heavy metals were identified as non-residual chemical forms, and those are very susceptible to the change of ambient conditions of a nearby environment. The concept of pollution index(PI) of soils gives important information on the extent and degree of multi-element contamination, and can be applied to the evaluation of mine soils before their agricultural use and remediation. The risk assessment process comprising exposure assessment, dose-response assessment, and risk characterization was discussed, and the results of non-cancer risk of As, Cd, and Zn, and those of cancer risk of As were suggested.

Oribatid communities and heavy metal bioaccumulation in selected species associated with lichens in a heavily contaminated habitat.

PubMed

Skubała, Piotr; Rola, Kaja; Osyczka, Piotr

2016-05-01

The study examines oribatid communities and heavy metal bioaccumulation in selected species associated with different microhabitats of a post-smelting dump, i.e. three lichen species of Cladonia with various growth forms and the slag substrate. The abundance of oribatids collected from the substrate was significantly lower than observed in lichen thalli. The morphology and chemical properties of lichens, and to some extent varying concentrations of heavy metals in thalli, are probably responsible for significant differences in oribatid communities inhabiting different Cladonia species. Some oribatids demonstrate the ability to accumulate zinc and cadmium with unusual efficiency, whereas lead is the most effectively regulated element by all species. A positive correlation was found between Zn content in all studied oribatids and their microhabitats. Oribatids exploring different food resources, i.e. fungivorous and non-fungivorous grazers, show considerable differences in bioconcentrations of certain elements.

On-line/on-site analysis of heavy metals in water and soils by laser induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Meng, Deshuo; Zhao, Nanjing; Wang, Yuanyuan; Ma, Mingjun; Fang, Li; Gu, Yanhong; Jia, Yao; Liu, Jianguo

2017-11-01

The enrichment method of heavy metal in water with graphite and aluminum electrode was studied, and combined with plasma restraint device for improving the sensitivity of detection and reducing the limit of detection (LOD) of elements. For aluminum electrode enrichment, the LODs of Cd, Pb and Ni can be as low as several ppb. For graphite enrichment, the measurement time can be less than 3 min. The results showed that the graphite enrichment and aluminum electrode enrichment method can effectively improve the LIBS detection ability. The graphite enrichment method combined with plasma spatial confinement is more suitable for on-line monitoring of industrial waste water, the aluminum electrode enrichment method can be used for trace heavy metal detection in water. A LIBS method and device for soil heavy metals analysis was also developed, and a mobile LIBS system was tested in outfield. The measurement results deduced from LIBS and ICP-MS had a good consistency. The results provided an important application support for rapid and on-site monitoring of heavy metals in soil. (Left: the mobile LIBS system for analysis of heavy metals in soils. Top right: the spatial confinement device. Bottom right: automatic graphite enrichment device for on0line analysis of heavy metals in water).

Detection of pristine gas two billion years after the Big Bang.

PubMed

Fumagalli, Michele; O'Meara, John M; Prochaska, J Xavier

2011-12-02

In the current cosmological model, only the three lightest elements were created in the first few minutes after the Big Bang; all other elements were produced later in stars. To date, however, heavy elements have been observed in all astrophysical environments. We report the detection of two gas clouds with no discernible elements heavier than hydrogen. These systems exhibit the lowest heavy-element abundance in the early universe, and thus are potential fuel for the most metal-poor halo stars. The detection of deuterium in one system at the level predicted by primordial nucleosynthesis provides a direct confirmation of the standard cosmological model. The composition of these clouds further implies that the transport of heavy elements from galaxies to their surroundings is highly inhomogeneous.

[Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

PubMed

Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

2014-09-01

The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb < Cu < Cd < Cr < As < Zn. The heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd < Cu < As < Cr

Hydroponics reducing effluent's heavy metals discharge.

PubMed

Rababah, Abdellah; Al-Shuha, Ahmad

2009-01-01

This paper investigates the capacity of Nutrient Film Technique (NFT) to control effluent's heavy metals discharge. A commercial hydroponic system was adapted to irrigate lettuces with primary treated wastewater for studying the potential heavy metals removal. A second commercial hydroponic system was used to irrigate the same type of lettuces with nutrient solution and this system was used as a control. Results showed that lettuces grew well when irrigated with primary treated effluent in the commercial hydroponic system. The NFT-plant system heavy metals removal efficiency varied amongst the different elements, The system's removal efficiency for Cr was more than 92%, Ni more than 85%, in addition to more than 60% reduction of B, Pb, and Zn. Nonetheless, the NFT-plants system removal efficiencies for As, Cd and Cu were lower than 30%. Results show that lettuces accumulated heavy metals in leaves at concentrations higher than the maximum acceptable European and Australian levels. Therefore, non-edible plants such as flowers or pyrethrum are recommended as value added crops for the proposed NFT.

Particle Size Distribution of Heavy Metals and Magnetic Susceptibility in an Industrial Site.

PubMed

Ayoubi, Shamsollah; Soltani, Zeynab; Khademi, Hossein

2018-05-01

This study was conducted to explore the relationships between magnetic susceptibility and some soil heavy metals concentrations in various particle sizes in an industrial site, central Iran. Soils were partitioned into five fractions (< 28, 28-75, 75-150, 150-300, and 300-2000 µm). Heavy metals concentrations including Zn, Pb, Fe, Cu, Ni and Mn and magnetic susceptibility were determined in bulk soil samples and all fractions in 60 soil samples collected from the depth of 0-5 cm. The studied heavy metals except for Pb and Fe displayed a substantial enrichment in the < 28 µm. These two elements seemed to be independent of the selected size fractions. Magnetic minerals are specially linked with medium size fractions including 28-75, 75-150 and 150-300 µm. The highest correlations were found for < 28 µm and heavy metals followed by 150-300 µm fraction which are susceptible to wind erosion risk in an arid environment.

HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance

NASA Astrophysics Data System (ADS)

Wakeford, Hannah R.; Sing, David K.; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D.; Tremblin, Pascal; Amundsen, David S.; Lewis, Nikole K.; Mandell, Avi M.; Fortney, Jonathan J.; Knutson, Heather; Benneke, Björn; Evans, Thomas M.

2017-05-01

A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H2O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b’s atmospheric heavy element content (4.8-4.0+21.5 times solar). This likely indicates that HAT-P-26b’s atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals.

Water hyacinth as indicator of heavy metal pollution the tropics

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

Gonzalez, H.; Otero, M.; Lodenius, M.

1989-12-01

The water hyacinth (Eichhornia crassipes) is a common aquatic plant in many tropical countries. Its ability absorb nutrients and other elements from the water has made it possible to use it for water purification purposes. Eichhornia, especially stems and leaves, have been successfully used as indicators of heavy metal pollution in tropical countries. The uptake of heavy metals in this plant is stronger in the roots than in the floating shoots. Metallothionein-like compounds have been found from roots of this species after cadmium exposure. The purpose of this investigation was to study the possibilities of using roots of water hyacinthmore » as a biological indicator of metal pollution in tropical aquatic ecosystems.« less

Coexistence of Heavy Metal and Antibiotic Resistance within a Novel Composite Staphylococcal Cassette Chromosome in a Staphylococcus haemolyticus Isolate from Bovine Mastitis Milk

PubMed Central

Xue, Huping; Wu, Zhaowei; Li, Longping; Li, Fan; Wang, Yiqing

2015-01-01

The structure of a composite staphylococcal cassette chromosome (SCC) carried by a methicillin-resistant Staphylococcus haemolyticus (NW19A) isolated from a bovine milk sample was analyzed. The formation of the circular forms of both single SCC elements and composite SCC elements was detected in NW19A. Twenty heavy metal and antibiotic resistance-related genes coexisted in this composite SCC, suggesting that these genes might be coselected under environmental pressure. The mec gene complex in NW19A, designated type C3, is different from classic C1 or C2 gene complexes structurally and likely evolves differently. Furthermore, results from alignment of the SCC composite island of NW19A with 50 related sequences from different staphylococcal strains provided additional evidence to support the notion that coagulase-negative staphylococci (CoNS) are the original host of heavy metal resistance genes among staphylococci. Given that a SCC composite island could transfer freely among different staphylococcal species from different hosts, more attention should be paid to contamination with heavy metals and antibiotics in dairy farming environments, including wastewater, soil, feces, and feed. PMID:26169408

Coexistence of heavy metal and antibiotic resistance within a novel composite staphylococcal cassette chromosome in a Staphylococcus haemolyticus isolate from bovine mastitis milk.

PubMed

Xue, Huping; Wu, Zhaowei; Li, Longping; Li, Fan; Wang, Yiqing; Zhao, Xin

2015-09-01

The structure of a composite staphylococcal cassette chromosome (SCC) carried by a methicillin-resistant Staphylococcus haemolyticus (NW19A) isolated from a bovine milk sample was analyzed. The formation of the circular forms of both single SCC elements and composite SCC elements was detected in NW19A. Twenty heavy metal and antibiotic resistance-related genes coexisted in this composite SCC, suggesting that these genes might be coselected under environmental pressure. The mec gene complex in NW19A, designated type C3, is different from classic C1 or C2 gene complexes structurally and likely evolves differently. Furthermore, results from alignment of the SCC composite island of NW19A with 50 related sequences from different staphylococcal strains provided additional evidence to support the notion that coagulase-negative staphylococci (CoNS) are the original host of heavy metal resistance genes among staphylococci. Given that a SCC composite island could transfer freely among different staphylococcal species from different hosts, more attention should be paid to contamination with heavy metals and antibiotics in dairy farming environments, including wastewater, soil, feces, and feed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

[Speciation Characteristics and Bioavailability of Heavy Metals in Oasis Soil Under Pb, Zn Combined Stress].

PubMed

Jin, Cheng; Zhao, Zhuan-jun; Nan, Zhong-ren; Wang, Sheng-li; Wu, Wen-fei; Wang, Hou-cheng

2015-05-01

Pot experiments were conducted on cole (Brassica) grown in oasis soil under combined stress of lead and zinc, to study the effect of heavy metal combined pollution on cole growth as well as the speciation conversion rules and bioavailability. The result showed that the promoting effect on cole growth was shown in the low concentration treatments, especially on stem leaves. With addition of exotic heavy metals, the main speciations of Pb and Zn in the soil transformed from tight-bound to loose-bound forms as compared to the control, and the bioavailability of heavy metals was increased. And, the exchangeable Pb and the carbonate bound form of Zn were the major contributing speciations which were absorbed in different parts of cole. What's more, the capabilities of uptake and translocation of Pb and Zn by cole were stronger at lower stress levels, and the enrichment and migration coefficients decreased with the increasing content of bioavailable fraction of the corresponding element or the coexisting element. In all treatments, the Pb concentration in the stem leaves of cole exceeded the food safety threshold, therefore it is recommended to conduct detection of relevant indicators before planting foliage vegetables in this kind of soil.

The influence of different types of pesticides on elemental profiles of some fruit trees: Apple and plum

NASA Astrophysics Data System (ADS)

Gheboianu, Anca Irina; Setnescu, Tanta; Setnescu, Radu; Culicov, Otilia; Zinicovscaia, Inga

2017-12-01

The aim of this study is to evaluate the elemental content of various samples from apple and plum orchard - located in Dambovita and Arges Counties - (soil, bark and leaves) and to characterize the influence of different types of pesticides commonly used in orchards. For this purpose, the effect of pesticide/ natural fertilizer couples was studied by characterization of treated and untreated soil composition. Heavy metals were also used as tracers for pesticides concentration monitoring, aiming to get information about their overall concentration and eventually, their critical accumulation into some parts of the studied plants (which shall not exceed the limits regulated by Romanian law and UE directives for pesticides use in fruit-grower). Solid samples were analyzed by wavelength dispersion X-ray fluorescence (WDXRF) and instrumental nuclear activation methods (INAA). Moreover, soil properties (pH and electrical conductivity) were determined in order to characterize agricultural soils and to analyze relationships between heavy metal contents and soil properties. Multivariate data analysis was performed to identify a common source for heavy metals. Correlations between the concentrations of heavy metals in the analyzed samples and pesticides used in these areas were found.

Earliest evidence of pollution by heavy metals in archaeological sites.

PubMed

Monge, Guadalupe; Jimenez-Espejo, Francisco J; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

2015-09-21

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called "Anthropocene". According to its heavy metal concentration, these sediments meet the present-day standards of "contaminated soil". Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

Silicon occurrence, uptake, transport and mechanisms of heavy metals, minerals and salinity enhanced tolerance in plants with future prospects: A review.

PubMed

Imtiaz, Muhammad; Rizwan, Muhammad Shahid; Mushtaq, Muhammad Adnan; Ashraf, Muhammad; Shahzad, Sher Muhammad; Yousaf, Balal; Saeed, Dawood Anser; Rizwan, Muhammad; Nawaz, Muhammad Azher; Mehmood, Sajid; Tu, Shuxin

2016-12-01

Recently, heavy metals pollution due to industrialization and urbanization, use of untreated wastewater and unreasonable use of pesticides and fertilizers is increasing rapidly, resulting in major threat to the environment and contaminate soils. Silicon (Si) is the second most abundant element in the earth crust after oxygen. Although it's higher accumulation in plants, yet Si has not been listed as essential nutrient however, considered as beneficial element for growth of plants particularly in stressed environment. Research to date has demonstrated that silicon helps the plants to alleviate the various biotic and abiotic stresses. This review article presents a comprehensive update about Si and heavy metals, minerals and salinity stresses, and contained the progress about Si so far done worldwide in the light of previous studies to evaluate the ecological importance of Si. Moreover, this review will also be helpful to understand the Si uptake ability and its benefits on plants grown under stressed environment. Further research needs for Si-mediated mitigation of heavy metals and mineral nutrients stresses are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of the effects of phosphate fertilizer application on the heavy metal content in agricultural soils with different cultivation patterns.

PubMed

Cheraghi, Mehrdad; Lorestani, Bahareh; Merrikhpour, Hajar

2012-01-01

The use of phosphate fertilizers is essential in agriculture, because they supply farmland with nutrients for growing plants. However, heavy metals might be included as impurities in natural materials and minerals, so heavy metals can also be present in phosphate fertilizers or other chemical fertilizers. The aim of this work was to assess the heavy metal content and contamination status of agricultural soils in the Hamadan province of Iran used for the cultivation of different crops, including cucumber, potatoes, and sugar beet. Surface soil samples were collected and analyzed to determine the total concentration of specific elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), before the pollution index was calculated for each element. Soils used for the cultivation of the three types of crop were not contaminated with As, Cr, Cu, Pb, or Zn. However, the pollution indices for Cd were 1.1, 4.4, and 3.8 in cucumber, potato, and sugar beet fields, respectively, which indicated moderate, high, and high levels of contamination, respectively. Soils from potato and sugar beet fields were heavily contaminated with Cd, which may have resulted from long-term overuse of phosphate fertilizers.

Molecular identification of isolated fungi, microbial and heavy metal contamination of canned meat products sold in Riyadh, Saudi Arabia

PubMed Central

Nasser, Laila A.

2014-01-01

Several studies have shown that canned meat products may be contaminated with fungal elements, bacteria and even heavy metals which may occur during the transportation, storage and handling processes. We conducted this study to determine the fungal, microbial and heavy metal contents of canned meats in Saudi Arabia. Of the 13 canned meat samples studied, Aspergillus and Penicillium were found in more than 70% of the total samples. Sequences of Penicillium species isolated from meat samples generated a phylogenetic tree which shows that the studied isolates were clustered in four groups. No bacterial contamination was noted in all of the samples. Nine of the 13 samples had iron concentrations above the permissible limit. All samples had zinc and copper levels below the maximum permissible limit. Four samples had cadmium levels above the maximum permissible level. All samples had levels of lead above the maximum permissible levels. These results indicate that fungal elements and higher levels of heavy metals such as lead and cadmium can be found in canned meat products. This may pose as a real danger to consumers, since canned meat products are readily accessible and convenient in Saudi Arabia. PMID:26288552

Elemental analyses of pine bark and wood in an environmental study.

PubMed

Saarela, K-E; Harju, L; Rajander, J; Lill, J-O; Heselius, S-J; Lindroos, A; Mattsson, K

2005-05-01

Bark and wood samples were taken from the same individuals of Scots pine (Pinus sylvestris L.) from a polluted area close to a Cu-Ni smelter in Harjavalta and from some relatively unpolluted areas in western Finland. The samples were analysed by thick-target particle induced X-ray emission (PIXE) after preconcentration by dry ashing at 550 degrees C. The elemental contents of pine bark and wood were compared to study the impact of heavy metal pollution on pine trees. By comparison of the elemental contents in ashes of bark and wood, a normalisation was obtained. For the relatively clean areas, the ratios of the concentration in bark ash to the concentration in wood ash for different elements were close to 1. This means that the ashes of Scots Pine wood and bark have quite similar elemental composition. For the samples from the polluted area the mean concentration ratios for some heavy metals were elevated (13-28), reflecting the effect of direct atmospheric contamination. The metal contents in the ashes of pine bark and wood were also compared to recommendations for ashes to be recycled back to the forest environment. Bark from areas close to emission sources of heavy metal pollution should be considered with caution if aiming at recycling the ash. Burning of bark fuel of pine grown within 6 km of the Cu-Ni smelter is shown to generate ashes with high levels of Cu, Ni as well as Cd, As and Pb.

Prospecting for Precious Metals in Ultra-Metal-Poor Stars

NASA Astrophysics Data System (ADS)

French, R. S.

2000-05-01

The chemical compositions of the most metal-poor halo stars are living records of the very early nucleosynthetic history of the Galaxy. Only a few prior generations, if not a single one, of element-donating supernovae could have been responsible for the heavy elements observed in ultra-metal-poor (UMP; [Fe/H] < --2.5) stars. Abundances of the heavy neutron-capture elements (Z > 30) can yield direct information about the supernova progenitors to UMP stars, and abundances of unstable thorium and uranium (Z = 90, 92) can potentially provide age estimates for the Galactic halo. Already, many studies have demonstrated that abundances of rare-earth elements (56 <= Z <= 72) in UMP stars are completely consistent with their production in rapid neutron-capture synthesis (r-process) events, usually believed to occur during supernovae explosions. Therefore, mapping the entire abundance pattern of UMP stars is of significant interest. In particular, abundances of the most massive stable elements (Os -> Pb or 76 <= Z <= 82) could provide crucial information about the so-called ``third r-process peak,'' and are critical to the radioactive-dating technique that uses unstable thorium as a chronometer. Until recently, abundance determinations for these elements have been virtually non-existent, as the strongest relevant transitions lay in the vacuum UV, inaccessible to ground-based observation. The availability of high-resolution space-based spectrometers has opened up new regions of spectral coverage, including precisely the range in wavelength needed to make these sensitive measurements. We have undertaken a study of about 10 metal-poor halo giants to determine the abundances of several of the heaviest neutron-capture elements including platinum, osmium, lead, and gold. Preliminary results indicate that the abundance pattern of heavy neutron-capture elements (56 <= Z <= 82) in UMP stars does mimic a scaled solar system r-process. Thus, the ability to estimate the initial abundances of thorium and uranium is greatly reinforced.

Informal e-waste recycling: environmental risk assessment of heavy metal contamination in Mandoli industrial area, Delhi, India.

PubMed

Pradhan, Jatindra Kumar; Kumar, Sudhir

2014-01-01

Nowadays, e-waste is a major source of environmental problems and opportunities due to presence of hazardous elements and precious metals. This study was aimed to evaluate the pollution risk of heavy metal contamination by informal recycling of e-waste. Environmental risk assessment was determined using multivariate statistical analysis, index of geoaccumulation, enrichment factor, contamination factor, degree of contamination and pollution load index by analysing heavy metals in surface soils, plants and groundwater samples collected from and around informal recycling workshops in Mandoli industrial area, Delhi, India. Concentrations of heavy metals like As (17.08 mg/kg), Cd (1.29 mg/kg), Cu (115.50 mg/kg), Pb (2,645.31 mg/kg), Se (12.67 mg/kg) and Zn (776.84 mg/kg) were higher in surface soils of e-waste recycling areas compared to those in reference site. Level exceeded the values suggested by the US Environmental Protection Agency (EPA). High accumulations of heavy metals were also observed in the native plant samples (Cynodon dactylon) of e-waste recycling areas. The groundwater samples collected form recycling area had high heavy metal concentrations as compared to permissible limit of Indian Standards and maximum allowable limit of WHO guidelines for drinking water. Multivariate analysis and risk assessment studies based on total metal content explains the clear-cut differences among sampling sites and a strong evidence of heavy metal pollution because of informal recycling of e-waste. This study put forward that prolonged informal recycling of e-waste may accumulate high concentration of heavy metals in surface soils, plants and groundwater, which will be a matter of concern for both environmental and occupational hazards. This warrants an immediate need of remedial measures to reduce the heavy metal contamination of e-waste recycling sites.

Influence of Heavy Metal Stress on Antioxidant Status and DNA Damage in Urtica dioica

PubMed Central

Kadifkova Panovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

2013-01-01

Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity. PMID:23862140

Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries

PubMed Central

Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

2016-01-01

Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments. PMID:27681994

Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries.

PubMed

Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

2016-09-29

Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.

Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries

NASA Astrophysics Data System (ADS)

Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

2016-09-01

Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.

Conifer needles as biomonitors of atmospheric heavy metal deposition: comparison with mosses and precipitation, role of the canopy

NASA Astrophysics Data System (ADS)

Čeburnis, D.; Steinnes, E.

Concentrations of seven elements (As, Cd, Cr, Mn, Pb, V, Zn) in mosses ( Hylocomium splendens, Pleurozium schreberi, Eurhynchium angustirete) and needles of Norway spruce ( Picea abies) and juniper ( Juniperus communis) were determined at 48 sites in Lithuania. Conifer needles consistently showed many times lower concentrations than mosses collected at the same site. Correlations between heavy-metal concentrations in needles and mosses indicated that accumulation processes may be similar, but mosses appear to be clearly preferable as biomonitors of atmospheric deposition because of their higher elemental concentrations and more quantitative reflection of deposition rates. Precipitation in the open field and under the canopy was investigated at two stations with respect to the same metals. The canopy was shown to retain a considerable part of lead, whereas elements such as Zn and Mn were enriched in precipitation under the canopy. Study of metal concentrations in moss growing, respectively, below and outside the canopy showed that none of so studied elements was significantly retained by the canopy. Most of the metals (Cu, Fe, Zn, Cr, Ni, V) were leached from the canopy to a smaller or greater extent.

Analysis of traditional Tibetan pills

NASA Astrophysics Data System (ADS)

Cesnek, Martin; Štefánik, Milan; Miglierini, Marcel; Kmječ, Tomáš; Sklenka, L'ubomír

2017-11-01

Traditional Tibetan medicine starts to be a very popular complementary medicine in USA and Europe. These pills contain many elements essential for the human body. However, they might also contain heavy metals such as mercury, iron, arsenic, etc. This paper focuses on elemental composition of two Tibetan pills and investigation of forms of iron in them. X-ray fluorescence spectroscopy and neutron activation analysis identified the presence of several heavy metals such as mercury, iron and copper. Mőssbauer spectroscopy revealed the possible presence of α - F e 2 O 3(hematite) and α - F e O O H(goethite) in both of the investigated samples.

Stellar Abundance Observations and Heavy Element Formation

NASA Astrophysics Data System (ADS)

Cowan, J. J.

2005-05-01

Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy -- the progenitors of the halo stars -- responsible for neutron-capture synthesis of the heavy elements. Abundance comparisons among the r-process-rich halo stars show that the heaviest neutron-capture elements (i.e., Ba and above) are consistent with a scaled solar system r-process abundance distribution, while the lighter neutron-capture elements do not conform to the solar pattern. These comparisons suggest the possibility of two r-process sites in stars. The large star-to-star scatter observed in the abundances of neutron-capture element/iron ratios at low metallicities -- which disappears with increasing metallicity or [Fe/H] -- suggests the formation of these heavy elements (presumably from certain types of supernovae) was rare in the early Galaxy. The stellar abundances also indicate a change from the r-process to the slow neutron capture (i.e., s-) process at higher metallicities in the Galaxy and provide insight into Galactic chemical evolution. Finally, the detection of thorium and uranium in halo and globular cluster stars offers an independent age-dating technique that can put lower limits on the age of the Galaxy, and hence the Universe. This work has been supported in part by NSF grant AST 03-07279 (J.J.C.) and by STScI grants GO-8111, GO-8342 and GO-9359.

Heavy metals in particulate and colloidal matter from atmospheric deposition of urban Guangzhou, South China.

PubMed

Huang, Wen; Duan, Dandan; Zhang, Yulong; Cheng, Hefa; Ran, Yong

2014-08-30

Suspended particulate matter (SPM) and colloidal matter (COM) in annual dry and wet deposition samples in urban Guangzhou were for the first time collected, and their trace metals were investigated by using inductively coupled plasma mass spectrometry (ICP-MS). The deposition flux of SPM and of metal elements varied largely among the investigated seasons, and reached the maximum in spring. The correlation analysis indicated that significant correlations existed among some of the metal elements in the deposition samples. The enrichment factors (EF) of metals in COM in the deposition ranging from 79.66 to 130,000 were much higher than those of SPM ranging from 1.65 to 286.48, indicating the important role of COM. The factor analysis showed that emissions from street dust, non-ferrous metal production, and heavy fuel oil were major sources of the trace metals. Positive matrix factorization (PMF) model was used to quantitatively estimate anthropogenic source. Copyright © 2013 Elsevier Ltd. All rights reserved.

Maps of heavy metals in the soils of the European Union and proposed priority areas for detailed assessment.

PubMed

Tóth, Gergely; Hermann, Tamás; Szatmári, Gábor; Pásztor, László

2016-09-15

Soil contamination is one of the greatest concerns among the threats to soil resources in Europe and globally. Despite of its importance there was only very course scale (1/5000km(2)) data available on soil heavy metal concentrations prior to the LUCAS topsoil survey, which had a sampling density of 200km(2). Based on the results of the LUCAS sampling and auxiliary information detailed and up-to-date maps of heavy metals (As, Cd, Cr, Cu, Hg, Pb, Zn, Sb, Co and Ni) in the topsoil of the European Union were produced. Using the maps of heavy metal concentration in topsoil we made a spatial prediction of areas where local assessment is suggested to monitor and eventually control the potential threat from heavy metals. Most of the examined elements remain under the corresponding threshold values in the majority of the land of the EU. However, one or more of the elements exceed the applied threshold concentration on 1.2Mkm(2), which is 28.3% of the total surface area of the EU. While natural backgrounds might be the reason for high concentrations on large proportion of the affected soils, historical and recent industrial and mining areas show elevated concentrations (predominantly of As, Cd, Pb and Hg) too, indicating the magnitude of anthropogenic effect on soil quality in Europe. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Efficient and selective heavy metal sequestration from water by using layered sulfide K 2x Sn 4-x S 8-x (x = 0.65–1; KTS-3)

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

Sarma, Debajit; Islam, Saiful M.; Subrahmanyam, K. S.

Heavy metal ions (Cd 2+, Hg 2+, As 3+ and Pb 2+) are an important contributor to the contamination of groundwater and other water bodies in and around industrial areas. Herein, we demonstrate the rapid and efficient capacity of a layered metal sulfide material, K2xSn4-xS8-x (x = 0.65-1, KTS-3) for heavy metal ion removal from water. The effect of concentration, pH, kinetics, and competitive ions such as Na +/Ca 2+ on the heavy metal ion removal capacity of KTS-3 was systematically investigated. X-ray photoelectron spectroscopy (XPS), elemental analyses, and powder X-ray diffraction studies revealed that the heavy metal ion-exchange ofmore » KTS-3 is complete (quantitative replacement of all potassium ions) and topotactic. The heavy metal ion-exchange by using KTS-3 follows the Langmuir-Freundlich model with high exchange capacities, q(m) 205(17) mg g -1 for Cd 2+, 372(21) mg g -1 for Hg 2+ and 391(89) mg g -1 for Pb 2+. KTS-3 retains excellent heavy metal ion-exchange capacity even in very high concentration (1 M) of competing ions (Na +/Ca 2+) and also over a broad pH range (2-12). KTS-3 also exhibits very good ion-exchange capacity for precious Ag + and toxic As 3+ ions. The kinetics of heavy metal ion adsorption by KTS-3 are rapid (absorbs all ions within a few minutes). These properties and the environmentally friendly character of KTS-3 make it a promising candidate for sequestration of heavy metal ions from water.« less

Application of biosolids in mineral sands mine rehabilitation: use of stockpiled topsoil decreases trace element uptake by plants.

PubMed

Rate, Andrew W; Lee, Karen M; French, Peter A

2004-02-01

Mineral sands mining involves stripping topsoil to access heavy-mineral bearing deposits, which are then rehabilitated to their original state, commonly pasture in south-west Western Australia. Organic amendments such as biosolids (digested sewage sludge) can contribute organic carbon to the rehabilitating system and improve soil chemical fertility and physical conditions. Use of biosolids also introduces the risk of contamination of the soil-plant system with heavy metals, but may be a useful source of trace elements to plants if the concentrations of these elements are low in unamended soil. We expected that biosolids amendment of areas mined for mineral sands would result in increased concentrations of metals in soils and plants, and that metal uptake would be decreased by adding stockpiled topsoil or by liming. A glasshouse experiment growing a mixed annual ryegrass (Lolium rigidum)-subterranean clover (Trifolium subterraneum) sward was conducted using two soil materials (residue sand/clay and conserved topsoil) from a mineral sands mine amended with different rates of biosolids (0, 10, 20, 50 dry t/ha), and including a liming treatment (2 t/ha). Total concentrations of metals (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) in soil increased with increasing rate of biosolids application. Metal uptake was generally lower where topsoil was present and was decreased by liming. With increasing biosolids application, plant metal concentrations increased for Cd, Ni and Zn but decreased or were erratic for other elements. In clover, biosolids application removed the Zn deficiency observed where biosolids were not applied. Plant uptake of all elements increased with increasing biosolids application, suggesting dilution by increased plant biomass was responsible for erratic metal concentration results. Despite the observed increases in uptake of metals by plants, metal concentrations in both species were low and below food standard thresholds. It is unlikely that a single application of biosolids in this system posed a threat from heavy metal contamination of soils or plants, and was beneficial in terms of Zn nutrition of T. subterraneum.

Direct identification of trace metals in fine and ultrafine particles in the Detroit urban atmosphere.

PubMed

Utsunomiya, Satoshi; Jensen, Keld A; Keeler, Gerald J; Ewing, Rodney C

2004-04-15

Exposure to airborne particulates containing low concentrations of heavy metals, such as Pb, As, and Se, may have serious health effects. However, little is known about the speciation and particle size of these airborne metals. Fine- and ultrafine particles with heavy metals in aerosol samples from the Detroit urban area, Michigan, were examined in detail to investigate metal concentrations and speciation. The characterization of individual particles was completed using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) combined with conventional high-resolution TEM techniques. The trace elements, Pb, As, La, Ce, Sr, Zn, Cr, Se, Sn, Y, Zr, Au, and Ag, were detected, and the elemental distributions were mapped in situ atthe nanoscale. The crystal structures of the particles containing Pb, Sr, Zn, and Au were determined from their electron diffraction patterns. Based on the characterization of the representative trace element particles, the potential health effects are discussed. Most of the trace element particles detected in this study were within a range of 0.01-1.0 microm in size, which has the longest atmospheric residence time (approximately 100 days). Increased chemical reactivity owing to the size of nanoparticles may be expected for most of the trace metal particles observed.

Trace element carriers in combined sewer during dry and wet weather: an electron microscope investigation.

PubMed

El Samrani, A G; Lartiges, B S; Ghanbaja, J; Yvon, J; Kohler, A

2004-04-01

The nature of trace element carriers contained in sewage and combined sewer overflow (CSO) was investigated by TEM-EDX-Electron diffraction and SEM-EDX. During dry weather, chalcophile elements were found to accumulate in sewer sediments as early diagenetic sulfide phases. The sulfurization of some metal alloys was also evidenced. Other heavy metal carriers detected in sewage include metal alloys, some iron oxihydroxide phases and neoformed phosphate minerals such as anapaite. During rain events, the detailed characterization of individual mineral species allowed to differentiate the contributions from various specific sources. Metal plating particles, barite from automobile brake, or rare earth oxides from catalytic exhaust pipes, originate from road runoff, whereas PbSn alloys and lead carbonates are attributed to zinc-works from roofs and paint from building siding. Soil contribution can be traced by the presence of clay minerals, iron oxihydroxides, zircons and rare earth phosphates. However, the most abundant heavy metal carriers in CSO samples were the sulfide particles eroded from sewer sediments. The evolution of relative abundances of trace element carriers during a single storm event, suggests that the pollution due to the "first flush" effect principally results from the sewer stock of sulfides and previously deposited metal alloys, rather than from urban surface runoff.

Trace elements (Cu, Zn, and Hg) and δ13C/δ15N in seabird subfossils from three islands of the South China Sea and its implications.

PubMed

Xu, Liqiang; Liu, Xiaodong; Nie, Yaguang

2016-05-01

Seabird subfossils were collected on three islands of the Xisha Archipelago, South China Sea. Via elemental analysis, we identified that bird guano was a significant source for heavy metals Cu, Zn, and Hg. Cu and Zn levels in these guano samples are comparable to their levels in wildbird feces, but guano Hg was lower than previously reported. Trophic positions significantly impacted transfer efficiency of heavy metals by seabirds. Despite of a common source, trace elements, as well as stable isotopes (i.e., guano δ(13)C and collagen δ(15)N), showed island-specific characteristics. Bird subfossils on larger island had relatively greater metal concentrations and revealed higher trophic positions. Partition of element and isotope levels among the islands suggested that transfer efficacy of seabirds on different islands was different, and bird species were probably unevenly distributed among the islets. Island area is possibly a driving factor for distributions of seabird species.

Crystallographic phases in heavy rare earth metals under megabar pressures

NASA Astrophysics Data System (ADS)

Samudrala, G. K.; Vohra, Y. K.

2012-07-01

Experiments aimed at understanding the crystallographic phases of heavy rare earth metals were carried out in a diamond anvil cell at the Advanced Photon Source, Argonne National Laboratory. Heavy rare earth metals dysprosium (Dy), holmium (Ho), erbium (Er) and thulium (Tm) were compressed to multi-megabar pressures. The rare earth crystal sequence hcp→Sm-type→dhcp→distorted-fcc (dfcc) is observed in all four elements. Upon further compression, a structural transformation to a monoclinic C2/m phase has been observed. We summarize the results from these experiments and present Rietveld structural refinements on high pressure phases for the specific case of dysprosium.

Fractionation, Bioaccessibility, and Risk Assessment of Heavy Metals in the Soil of an Urban Recreational Area Amended with Composted Sewage Sludge

PubMed Central

Zhang, Tao; Shao, Yanqiu; Tian, Chao; Cattle, Stephen R.; Zhu, Ying; Song, Jinjuan

2018-01-01

A composted sewage sludge (CSS) was added to the soil of an urban garden at 5%, 10%, and 25% (w/w soil) and stabilised for 180 days. Samples were then collected and analysed for total heavy metal concentrations, chemical fractions, and bioaccessibility, together with some physicochemical properties. The results showed that the total chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) concentrations were increased with CSS addition rate. The CSS addition decreased the residual fractions of these four elements. The exchangeable Cr, Cu, and Pb fractions were very small or not detected, while Zn exhibited an increasing trend in its exchangeable fraction with CSS addition rate. The bioaccessibility of these four elements was increased with the CSS addition rate. Moreover, the Cr, Cu, and Zn bioaccessibility correlated positively with the total concentration, while the bioaccessibility of these four elements exhibited a negative correlation with the residual fraction. The fractionation and bioaccessibility of heavy metals may have also been influenced by pH, cation exchange capacity, and organic matter. The risk assessment code reflected the amended soil showed no or low environmental risks for Cr, Cu, and Pb and a medium risk for Zn. The hazardous index values and cancer risk levels indicated that the heavy metals in the soil amended with 25% CSS posed negligible potential noncarcinogenic and carcinogenic risks to children and adults via incidental ingestion. PMID:29597244

Contamination characteristics and source apportionment of heavy metals in topsoil from an area in Xi'an city, China.

PubMed

Chen, Xiuduan; Lu, Xinwei

2018-04-30

As soil-extractable elements potentially pose ecological and health risks, identifying their contamination characteristics and sources is crucial. Therefore, to understand topsoil trace elements in the urban ring zone from the Second Ring Road to the Third Ring of Xi'an city in China, we determined the concentrations of Zn, Co, V, As, Cu, Mn, Ba, Ni and Pb, and analyzed the sources of the contamination. The results showed that the individual pollution indices of Pb, Co, Cu, Zn, Ba, Ni, Mn, As, and V were 1.79, 1.48, 1.41, 1.33, 1.20, 1.07, 1.04, 0.99, and 0.99, respectively. Evaluation with the aid of the pollution load index (PLI) indicated slight soil contamination by these elements in the study area. Using the positive matrix factorization (PMF) method, we identified four sources of contamination, namely (1) a natural source, (2) traffic emission source, (3) industrial emission source, and (4) mixed source. PMF is an effective tool for source apportionment of heavy metals in topsoil. The contribution rates of the natural source, traffic source, mixed source, and industrial source to the heavy metal contamination were specified as 25.04%, 24.71%, 24.99%, and 25.26%, respectively. Considering the above, any attempt to reduce the soil environmental cost of urban development, has to take into account the heavy metal contamination of the topsoil from industries, traffic, and other activities. Copyright © 2018 Elsevier Inc. All rights reserved.

Heavy metal exposure from cooked rice grain ingestion and its potential health risks to humans from total and bioavailable forms analysis.

PubMed

Praveena, S M; Omar, N A

2017-11-15

Heavy metal in rice studies has attracted a greater concern worldwide. However, there have been limited studies on marketed rice samples although it represents a vital ingestion portion for a real estimation of human health risk. This study was aimed to determine both total and bioaccessible of trace elements and heavy metals (Cd, Cr, Cu, Co, Al, Zn, As, Pb and Fe) in 22 varieties of cooked rice using an inductively coupled plasma-optical emission spectroscopy. Both total and bioaccessible of trace elements and heavy metals were digested using closed-nitric acid digestion and Rijksinstituut voor Volksgezondheid en Milieu (RIVM) in vitro digestion model, respectively. Human health risks via Health Risk Assessment (HRA) were conducted to understand exposure risks involving adults and children representing Malaysian population. Zinc was the highest while As was the lowest contents for total and in their bioavailable forms. Four clusters were identified: (1) Pb, As, Co, Cd and Cr; (2) Cu and Al; (3) Fe and (4) Zn. For HRA, there was no any risks found from single element exposure. While potential carcinogenic health risks present for both adult and children from single As exposure (Life time Cancer Risk, LCR>1×10 -4 ). Total Hazard Quotient values for adult and children were 27.0 and 18.0, respectively while total LCR values for adult and children were 0.0049 and 0.0032, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of wastewater irrigation on chemical and physical properties of Petroselinum crispum.

PubMed

Keser, Gonca; Buyuk, Gokhan

2012-06-01

The present study was carried out to assess the impact of wastewater on parsley (Petroselinum crispum). The parameters determined for soil were pH, electrical conductivity (EC), soil organic matter (SOM), nutrient elements (Ca, Mg, Na, K, Mn, Cu, Zn, and Fe), and heavy metals (Cd, Cr, Ni, and Pb), while the parameters determined for the plant included pigment content, dry matter, nutrient element, and heavy metals. SOM, EC, and clay contents were higher, and pH was slightly acidic in soil treated with wastewater compared to control soil. The enrichment factors (EF) of the nutrient elements in contaminated soil are in the sequence of Na (2) > Ca (1.32) > Mn = Mg (1.17) > Cu (1.11) > Zn (1.08) > Fe (1.07) > K (0.93), while EF in parsley are Na (6.63) > Ca (1.60) > Mg (1.34) > Zn (1.15) > Fe (0.95) > Cu = K (0.90) > Mn (0.85). Application of wastewater significantly decreased dry matter, while photosynthetic pigment content increased in parsley. The enrichment of the heavy metals is in the sequence: Cd (1.142) > Pb (1.131) > Ni (1.112) > Cr (1.095). P. crispum shows a high transfer factor (TF > 1) for Cd signifying a high mobility of Cd from soil to plant. Thus, although the wastewater irrigation in parsley production aims to produce socioeconomic benefits, study results indicated that municipal wastewater is not suitable for irrigation of parsley because it has negative effects on plant and causes heavy metal accumulation.

Health risk assessment of heavy metals via dietary intake of five pistachio (Pistacia vera L.) cultivars collected from different geographical sites of Iran.

PubMed

Taghizadeh, Seyedeh Faezeh; Davarynejad, Gholamhossein; Asili, Javad; Nemati, Seyed Hossein; Rezaee, Ramin; Goumenou, Marina; Tsatsakis, Aristides M; Karimi, Gholamreza

2017-09-01

Pistachio is an important horticultural product and Iran is considered as a main pistachio producing country. Assessment of heavy metals in this export fruit is crucial for protecting public health against toxic heavy metals. The concentration of selected heavy metals in soil, water and five pistachio cultivars from four geographical regions of Iran were measured. Although none of the elements were detected in water irrigation, infield metal content in the soil had good correlation with that of pistachio. The highest amounts of Al, As, Co, Ni and Se were reported in samples collected from Sarakhs, Iran. Considering both cultivar and region effects on selected heavy metals concentration, Kaleghoochi cultivar from Sarakhs site showed the highest amount of Al, As, Ni and Se. The maximum concentration of Hg was found in Akbari cultivar collected from Damghan. In the Akbari and the Ahmad aghaei cultivars collected from Sarakhs and Damghan cultivation zones, respectively, the highest amount of Co were observed. Based on our results, the HI value for the consumers of Iranian pistachio was 0.066. It seems that the levels of heavy metals in these pistachio samples pose no risk to consumers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tunable magnetic and magnetocaloric properties in heavy rare-earth based metallic glasses through the substitution of similar elements

NASA Astrophysics Data System (ADS)

Zhang, Huiyan; Li, Ran; Zhang, Leilei; Zhang, Tao

2014-04-01

The influence of interchangeable substitution of similar heavy rare-earth-elements (HRE), i.e., Gd-Ho, Gd-Er, and Ho-Er, on the magnetic and magnetocaloric properties of HRE55Al27.5Co17.5 metallic glasses was evaluated. The magnetic transition temperature (TC) can be tuned in a wide temperature range from 8 K to 93 K by adjusting the substitutional concentration in the resulting metallic glasses. A roughly linear correlation between peak value of magnetic entropy change (|ΔSMpk|) and TC-2/3 was obtained in the three systems. This kind of substitutional adjustment provides a useful method for designing desirable candidates in metallic glasses with high magnetic entropy change, large magnetic cooling efficiency, and tunable TC for magnetic refrigerant in nitrogen and hydrogen liquefaction temperature ranges.

The origin, historical variations, and distribution of heavy metals in the Qiongzhou Strait and nearby marine areas

NASA Astrophysics Data System (ADS)

Zhang, Zhiqiang; Chen, Liang; Wang, Weiping; Li, Tuanjie; Zu, Tingting

2017-04-01

We analyzed heavy metal concentrations in a number of surface sediments and cores from the Qiongzhou Strait and surrounding marine areas. The areas of high concentrations are primarily outside the eastern mouth of the Qiongzhou Strait and on the west side of the Leizhou Peninsula, whereas the areas of low concentrations are located primarily in the eastern Qiongzhou Strait. The maximum Cd, Pb and Zn concentrations in the samples collected in our study do not exceed the official standards for marine sediments, whereas the concentrations of Cr and Cu slightly exceed the standards. Correlations exist between the concentrations of Cu, Pb, Zn, Cr and Cd, and the concentrations of these metals are positively correlated with the mean particle size (φ value), indicating that the finer sediments have adsorbed greater amounts of heavy metal elements than the coarser sediments. An evaluation of the potential environmental risks demonstrates that certain indices of heavy metal pollution and environmental risks are relatively low and may be assigned low risk levels, thereby indicating that, in terms of heavy metals, the marine sedimentary environment in this region is only mildly impacted. Our analysis of the contaminant origins shows that the heavy metals in this region primarily originate in the Pearl River Estuary and that a small amount of them is derived from local runoff. The elevated heavy metal concentrations from the upper sections of the cores started 130 years ago, which indicats that heavy metals in the surface sediments are primarily due to human activities associated with industrialization.

[Bioaccumulation of heavy metals by the dominant plants growing in Huayuan manganese and lead/zinc mineland, Xiangxi].

PubMed

Yang, Sheng-Xiang; Tian, Qi-Jian; Liang, Shi-Chu; Zhou, Yao-Yu; Zou, Hui-Cheng

2012-06-01

Heavy metal pollution is a major environmental problem of mine wasteland. Finding out the tolerant plants, which can adapt to the local climate and the soil conditions, is the premise of vegetation restoration. An extensive vegetation survey and sampling were conducted in Huayuan Mn and Pb/Zn mineland, 76 species belonging to 69 genera and 39 families were recorded. The main dominant species and their associated soils were determined for heavy metal concentrations. The results showed that soil Pb, Zn and Cd levels exceeded the threshold levels of Class II of China Environmental Quality Standard for Soils, which suggested minesoils might be polluted by the three elements. The main dominant plants can adapt to the unfavorable edaphic conditions of mineland and were tolerant to heavy metals. There were great variations of metal uptake and accumulation among different plant species. They were classified into three types according to the metal concentrations in the plant shoots and roots: the accumulator, e. g. Camellia oleifera and Dicranopteris dichotoma, absorbed a large amount of heavy metals by the roots and transported to the shoots, which can be used to clean up the soils containing light to moderate toxic metal concentration and with high-value; the root compartment, e. g. Rubus tephrodes, R. corchorifolius, R. chroosepalus, Artemisia princeps and Pteridium aquilinum also absorbed a large amount of heavy metals but held in the roots; and the excluder, e. g. Miscanthus sinensis, Imperata cylindrica, Indocalamus tessellatus and Toddalia asiatica, absorbed less heavy metals than the accumulators. The root compartment and the excluder were more suitable for remediation of the mine wastelands with high heavy metal concentration, low-value and extensive area.

Rapid screening of heavy metals and trace elements in environmental samples using portable X-ray fluorescence spectrometer, A comparative study

PubMed Central

McComb, Jacqueline Q.; Rogers, Christian; Han, Fengxiang X.; Tchounwou, Paul B.

2014-01-01

With industrialization, great amounts of trace elements and heavy metals have been excavated and released on the surface of the earth and dissipated into the environments. Rapid screening technology for detecting major and trace elements as well as heavy metals in variety of environmental samples is most desired. The objectives of this study were to determine the detection limits, accuracy, repeatability and efficiency of a X-ray fluorescence spectrometer (Niton XRF analyzer) in comparison with the traditional analytical methods, inductively coupled plasma optical emission spectrometer (ICP-OES) and inductively coupled plasma optical emission spectrometer (ICP-MS) in screening of major and trace elements of environmental samples including estuary soils and sediments, contaminated soils, and biological samples. XRF is a fast and non-destructive method in measuring the total concentration of multi--elements simultaneously. Contrary to ICP-OES and ICP-MS, XRF analyzer is characterized by the limited preparation required for solid samples, non-destructive analysis, increased total speed and high throughout, the decreased production of hazardous waste and the low running costs as well as multi-elemental determination and portability in the fields. The current comparative study demonstrates that XRF is a good rapid non-destructive method for contaminated soils, sediments and biological samples containing higher concentrations of major and trace elements. Unfortunately, XRF does not have sensitive detection limits of most major and trace elements as ICP-OES or ICP-MS but it may serve as a rapid screening tool for locating hot spots of uncontaminated field soils and sediments. PMID:25861136

Multi-element sewer slime impact pattern--a quantitative characteristic enabling identification of the source of heavy metal discharges into sewer systems.

PubMed

Kintrup, J; Wünsch, G

2001-11-01

The capability of sewer slime to accumulate heavy metals from municipal wastewater can be exploited to identify the sources of sewage sludge pollution. Former investigations of sewer slime looked for a few elements only and could, therefore, not account for deviations of the enrichment efficiency of the slime or for irregularities from sampling. Results of ICP-MS multi element determinations were analyzed by multivariate statistical methods. A new dimensionless characteristic "sewer slime impact" is proposed, which is zero for unloaded samples. Patterns expressed in this data format specifically extract the information required to identify the type of pollution and polluter quicker and with less effort and cost than hitherto.

Mitigation effects of silicon rich amendments on heavy metal accumulation in rice (Oryza sativa L.) planted on multi-metal contaminated acidic soil.

PubMed

Gu, Hai-Hong; Qiu, Hao; Tian, Tian; Zhan, Shu-Shun; Deng, Teng-Hao-Bo; Chaney, Rufus L; Wang, Shi-Zhong; Tang, Ye-Tao; Morel, Jean-Louis; Qiu, Rong-Liang

2011-05-01

The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and 40gkg(-1)) and steel slag (3 and 6gkg(-1)) increased soil pH from 4.0 to 5.0-6.4, decreased the phytoavailability of heavy metals by at least 60%, and further suppressed metal uptake by rice. Diffusion gradient in thin-film measurement showed the heavy metal diffusion fluxes from soil to solution decreased by greater than 84% after remediation. X-ray diffraction analysis indicated the mobile metals were mainly deposited as their silicates, phosphates and hydroxides in amended treatments. Moreover, it was found metal translocation from stem to leaf was dramatically restrained by adding amendments, which might be due to the increase of silicon concentration and co-precipitation with heavy metals in stem. Finally, a field experiment showed the trace element concentrations in polished rice treated with amendments complied with the food safety standards of China. These results demonstrated fly ash and steel slag could be effective in mitigating heavy metal accumulation in rice grown on multi-metal contaminated acidic soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

A review of heavy metals in indoor dust and its human health-risk implications.

PubMed

Tan, Sock Yin; Praveena, Sarva Mangala; Abidin, Emilia Zainal; Cheema, Manraj Singh

2016-12-01

Indoor dust acts as a media for heavy metal deposition. Past studies have shown that heavy metal concentration in indoor dust is affected by local human activities and atmospheric transport can have harmful effects on human health. Additionally, children are more sensitive to heavy metals due to their hand-to-mouth behaviour and rapid body development. However, limited information on health risks were found in past dust studies as these studies aimed to identify heavy metal concentrations and sources of indoor dust. The objective of this review is to discuss heavy metal concentration and sources influencing its concentration in indoor dust. Accordingly, high lead (Pb) concentration (639.10 μg/g) has been reported in heavy traffic areas. In addition, this review paper aims to estimate the health risk to children from heavy metals in indoor dust via multiple exposure pathways using the health-risk assessment (HRA). Urban areas and industrial sites have revealed high heavy metal concentration in comparison to rural areas. Hazard index (HI) values found in arsenic (As), chromium (Cr) and Pb were 21.30, 1.10 and 2.40, respectively, indicate that non-carcinogenic elements are found in children. Furthermore, most of the past studies have found that carcinogenic risks for As, cadmium (Cd), Cr and Pb were below the acceptable total lifetime cancer risk (TLCR) range (1×10-6-1×10-4). The results of health risk assessment in this review show that carcinogenic risk exists among children. Hence, this proves that future studies need to focus on children's carcinogenic risk in indoor dust studies in order to find out the sources of heavy metals in indoor dust. This review highlights the importance of having the HRA application using bioavailable heavy metal concentration as it provides more accurate health-risk estimation. Moreover, this review is also useful as a reference for policy decision making in protecting children's health.

Heavy metal speciation and risk assessment in dry land and paddy soils near mining areas at Southern China.

PubMed

Liu, Guannan; Wang, Juan; Zhang, Erxi; Hou, Jing; Liu, Xinhui

2016-05-01

Heavy metal contamination of soils has been a long-standing environmental problem in many parts of the world, and poses enormous threats to ecosystem and human health. Speciation of heavy metals in soils is crucial to assessing environmental risks from contaminated soils. In this study, total concentrations and speciation of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn were measured for agricultural soils near mines along the Diaojiang River in Guangxi Zhuang Autonomy Region, China. The sources of heavy metals in soils also were identified to assess their effect on speciation distribution of soil heavy metals. Furthermore, the speciation distribution of Cd and Zn, main soil heavy metal pollutants, in dry land and paddy soils were compared. Results showed that there were two severely polluted regions near mine area reaching alarming pollution level. As, Cd, Pb, and Zn were more affected by mining activities, showing very strong pollution level in soils. The mean percentage of exchangeable and carbonate fraction was highest and up to 46.8 % for Cd, indicating a high environmental risk. Greater bioavailable fractions of As, Cd, Cu, Mn, Pb, and Zn were found in soils heavily polluted by mining activities, whereas Cr and Ni as geogenic elements in the stable residual fraction. In addition, in the dry land soils, reducible fraction proportion of Cd was higher than that in the paddy soils, whereas exchangeable and carbonate fraction of Cd was lower than that in the paddy soils. Oxidizable fraction of Zn was higher in the paddy soils than that in the dry land soils. The results indicate that the sources of soil heavy metals and land types affect heavy metal speciation in the soil and are significant for environmental risk assessment of soil heavy metal pollutions.

Genotoxicity of 11 heavy metals detected as food contaminants in two human cell lines.

PubMed

Kopp, B; Zalko, D; Audebert, M

2018-04-01

Heavy metals, such as arsenic (As), antimony (Sb), barium (Ba), cadmium (Cd), cobalt (Co), germanium (Ge), lead (Pb), nickel (Ni), tellurium (Te), and vanadium (V) are widely distributed in the environment and in the food chain. Human exposure to heavy metals through water and food has been reported by different international agencies. Although some of these heavy metals are essential elements for human growth and development, they may also be toxic at low concentrations due to indirect mechanisms. In this study, the genotoxic and cytotoxic properties of 15 different oxidation statuses of 11 different heavy metals were investigated using high-throughput screening (γH2AX assay) in two human cell lines (HepG2 and LS-174T) representative of target organs (liver and colon) for food contaminants. Base on their lowest observed adverse effect concentration, the genotoxic potency of each heavy metal in each cell line was ranked in decreasing order, NaAsO 2  > CdCl 2  > PbCl 2 (only in LS-174T cells) > As 2 O 5  > SbCl 3  > K 2 TeO 3  > As 2 O 3 . No significant genotoxicity was observed with the other heavy metals tested. Cell viability data indicate that several heavy metals (As, Cd, Co, Ni, Sb, and Te) induce cytotoxicity at high concentrations, whereas an increase in the number of cells was observed for lead concentrations >100 µM in both cell lines tested, suggesting that lead stimulates cell growth. All these results highlight the possible human health hazards associated with the presence of heavy metals present in food. Environ. Mol. Mutagen. 59:202-210, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Human health risk assessment of heavy metals in urban stormwater.

PubMed

Ma, Yukun; Egodawatta, Prasanna; McGree, James; Liu, An; Goonetilleke, Ashantha

2016-07-01

Toxic chemical pollutants such as heavy metals (HMs) are commonly present in urban stormwater. These pollutants can pose a significant risk to human health and hence a significant barrier for urban stormwater reuse. The primary aim of this study was to develop an approach for quantitatively assessing the risk to human health due to the presence of HMs in stormwater. This approach will lead to informed decision making in relation to risk management of urban stormwater reuse, enabling efficient implementation of appropriate treatment strategies. In this study, risks to human health from heavy metals were assessed as hazard index (HI) and quantified as a function of traffic and land use related parameters. Traffic and land use are the primary factors influencing heavy metal loads in the urban environment. The risks posed by heavy metals associated with total solids and fine solids (<150μm) were considered to represent the maximum and minimum risk levels, respectively. The study outcomes confirmed that Cr, Mn and Pb pose the highest risks, although these elements are generally present in low concentrations. The study also found that even though the presence of a single heavy metal does not pose a significant risk, the presence of multiple heavy metals could be detrimental to human health. These findings suggest that stormwater guidelines should consider the combined risk from multiple heavy metals rather than the threshold concentration of an individual species. Furthermore, it was found that risk to human health from heavy metals in stormwater is significantly influenced by traffic volume and the risk associated with stormwater from industrial areas is generally higher than that from commercial and residential areas. Copyright © 2016 Elsevier B.V. All rights reserved.

Monitoring and assessment of heavy metal/metalloid concentration by inductively coupled plasma mass spectroscopy (ICP-MS) method in Gonyeli Lake, Cyprus.

PubMed

Alkas, Fehmi Burak; Shaban, Jehad Abdullah; Sukuroglu, Ayca Aktas; Kurt, Mehmet Ali; Battal, Dilek; Saygi, Sahan

2017-09-22

The presence of heavy metals/metalloids in the ecosystem has been an increasing ecological and global public health concern due to their potential to cause adverse health effects. For this reason, the accumulation of some heavy metals such as Cr, Mn, Ni, Cu, As, Cd, Pb was assessed by way of ICP-MS in water, sediment and fish (Cyprinus carpio) sampled from Gonyeli Lake, North Cyprus. The results showed that these metals/metalloids are found widespread throughout the study area. In water, most concentrated element was manganese with 92.1 ppb and least concentrated was lead with 0.914 ppb. In sediment, copper had the highest concentration with 613 ppm, and cadmium the lowest with 1.57 ppm. In fish tissues (muscle and gills), the most concentrated element was manganese with 12.5 ppm and the least concentrated cadmium with 0.017 ppm. These results indicate that future remediation efforts are indispensable for the rehabilitation of the lake.

Heavy metals in human teeth dentine: A bio-indicator of metals exposure and environmental pollution.

PubMed

Asaduzzaman, Khandoker; Khandaker, Mayeen Uddin; Binti Baharudin, Nurul Atiqah; Amin, Yusoff Bin Mohd; Farook, Mohideen Salihu; Bradley, D A; Mahmoud, Okba

2017-06-01

With rapid urbanization and large-scale industrial activities, modern human populations are being increasingly subjected to chronic environmental heavy metal exposures. Elemental uptake in tooth dentine is a bioindicator, the uptake occurring during the formation and mineralization processes, stored to large extent over periods of many years. The uptake includes essential elements, most typically geogenic dietary sources, as well as non-essential elements arising through environmental insults. In this study, with the help of the Dental Faculty of the University of Malaya, a total of 50 separate human teeth were collected from dental patients of various ethnicity, age, gender, occupation, dietary habit, residency, etc. Analysis was conducted using inductively coupled plasma-mass spectrometry (ICP-MS), most samples indicating the presence of the following trace elements, placed in order of concentration, from least to greatest: As, Mn, Ba, Cu, Cr, Pb, Zn, Hg, Sb, Al, Sr, Sn. The concentrations have been observed to increase with age. Among the ethnic groups, the teeth of ethnic Chinese showed marginally greater metal concentrations than those of the Indians and Malays, the teeth dentine of females generally showing greater concentrations than that of males. Greater concentrations of Hg, Cu and Sn were found in molars while Pb, Sr, Sb and Zn were present in greater concentrations in incisors. With the elevated concentration levels of heavy metals in tooth dentine reflecting pollution from industrial emissions and urbanization, it is evident that human tooth dentine can provide chronological information on exposure, representing a reliable bio-indicator of environmental pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficiency Evaluation of Food Waste Materials for the Removal of Metals and Metalloids from Complex Multi-Element Solutions.

PubMed

Massimi, Lorenzo; Giuliano, Antonella; Astolfi, Maria Luisa; Congedo, Rossana; Masotti, Andrea; Canepari, Silvia

2018-02-26

Recent studies have shown the potential of food waste materials as low cost adsorbents for the removal of heavy metals and toxic elements from wastewater. However, the adsorption experiments have been performed in heterogeneous conditions, consequently it is difficult to compare the efficiency of the individual adsorbents. In this study, the adsorption capacities of 12 food waste materials were evaluated by comparing the adsorbents' efficiency for the removal of 23 elements from complex multi-element solutions, maintaining homogeneous experimental conditions. The examined materials resulted to be extremely efficient for the adsorption of many elements from synthetic multi-element solutions as well as from a heavy metal wastewater. The 12 adsorbent surfaces were analyzed by Fourier transform infrared spectroscopy and showed different types and amounts of functional groups, which demonstrated to act as adsorption active sites for various elements. By multivariate statistical computations of the obtained data, the 12 food waste materials were grouped in five clusters characterized by different elements' removal efficiency which resulted to be in correlation with the specific adsorbents' chemical structures. Banana peel, watermelon peel and grape waste resulted the least selective and the most efficient food waste materials for the removal of most of the elements.

Analysis of heavy metals in road-deposited sediments.

PubMed

Herngren, Lars; Goonetilleke, Ashantha; Ayoko, Godwin A

2006-07-07

Road-deposited sediments were analysed for heavy metal concentrations at three different landuses (residential, industrial, commercial) in Queensland State, Australia. The sediments were collected using a domestic vacuum cleaner which was proven to be highly efficient in collecting sub-micron particles. Five particle sizes were analysed separately for eight heavy metal elements (Zn, Fe, Pb, Cd, Cu, Cr, Al and Mn). At all sites, the maximum concentration of the heavy metals occurred in the 0.45-75 microm particle size range, which conventional street cleaning services do not remove efficiently. Multicriteria decision making methods (MCDM), PROMETHEE and GAIA, were employed in the data analysis. PROMETHEE, a non-parametric ranking analysis procedure, was used to rank the metal contents of the sediments sampled at each site. The most polluted site and particle size range were the industrial site and the 0.45-75 microm range, respectively. Although the industrial site displayed the highest metal concentrations, the highest heavy metal loading coincided with the highest sediment load, which occurred at the commercial site. GAIA, a special form of principal component analysis, was applied to determine correlations between the heavy metals and particle size ranges and also to assess possible correlation with total organic carbon (TOC). The GAIA-planes revealed that irrespective of the site, most of the heavy metals are adsorbed to sediments below 150 microm. A weak correlation was found between Zn, Mn and TOC at the commercial site. This could lead to higher bioavailability of these metals through complexation reactions with the organic species in the sediments.

[Investigation and analysis of heavy metal pollution related to soil-Panax notoginseng system].

PubMed

Chen, Lu; Mi, Yan-Hua; Lin, Xin; Liu, Da-Hui; Zeng, Min; Chen, Xiao-Yan

2014-07-01

In this study, five heavy metals contamination of soil and different parts of Panax notoginseng in the plantation area was investigated. Analysis of heavy metals correlation between the planting soil and P. notoginseng; and the absorption and accumulation characteristics and translocation of soil heavy metals by P. notoginseng plants was revealed. Through field investigation and laboratory analytical methods, analysis of China's 30 different soil P. notoginseng origin and content of heavy metals in five different parts of the P. notoginseng plant content of heavy metals. The results revealed that the soil heavy metals should not be neglected in the plantation area Referring to the national soil quality standards (GB15608-1995), the excessive degree of soil heavy metals pollution showed Hg > As > Cd > Cr in the plantation area, and Pb content of soil was in the scope of the standard. Refer to 'Green Industry Standards for Import and Export of Medical Plants and Preparations', the excessive degree of heavy metals content of P. notoginseng plants showed As > Pb > Cr > Cd, and Hg content of plants was in the scope of the standard. Concentrations of five heavy metals of underground parts of P. notoginseng plants are higher than aboveground, and heavy metals elements are more concentrated in the root, followed by the rhizome of P. notoginseng plants. Heavy metal accumulation characteristics of the different parts of the P. notoginseng of the overall performance is the root > the rhizome > the root tuber > leaves > stems. From the point of view BCF value analysis of various parts of the P. notoginseng plants to absorb heavy metals in soil, BCF values of all samples were less than 1, description P. notoginseng not belong Hyperaccumulator. From the view of transportation and related analysis of the soil-P. notoginseng systems, the rhizome of P. notoginseng and the content of As and Cr in soil was significantly correlated, the root of P. notoginseng and the content of Cd in soil was significantly correlated, and no significant correlation between the other indicators. Through the analysis of transportation transfer coefficient showed: Pb, As and Cr are not easy to transport aboveground part from the underground, but Cd and Hg are relatively easy to transport stems from rhizome, the migration of five heavy metals in the aerial part is relatively strong, and heavy metal of stems is easily transported to the leaves. P. notoginseng does not belong to the enrichment of heavy metals in crops, especially for Hg in soil with strong patience. In survey area, the content of heavy metals of P. notoginseng's planting soil is relatively high, and the heavy metals As, Pb, Cr, Cd of P. notoginseng also exist heavy metals exceeded problems. Due to the presence of heavy metals in crops internal absorption and translocation of special laws, accumulation of heavy metals varied significantly in different parts of P. notoginseng. The overall, the performance for the heavy metal content of the underground parts is more than aboveground, it explain heavy metals of P. notoginseng plants is still the main source of the soiL Therefore, the key to control of planting area soil environmental quality and reduce exogenous harmful substances secondary pollution of soil in the cultivation process are to study and solve the heavy metals pollution problem of P. notoginseng.

Phytoremediation of heavy metals--concepts and applications.

PubMed

Ali, Hazrat; Khan, Ezzat; Sajad, Muhammad Anwar

2013-05-01

The mobilization of heavy metals by man through extraction from ores and processing for different applications has led to the release of these elements into the environment. Since heavy metals are nonbiodegradable, they accumulate in the environment and subsequently contaminate the food chain. This contamination poses a risk to environmental and human health. Some heavy metals are carcinogenic, mutagenic, teratogenic and endocrine disruptors while others cause neurological and behavioral changes especially in children. Thus remediation of heavy metal pollution deserves due attention. Different physical and chemical methods used for this purpose suffer from serious limitations like high cost, intensive labor, alteration of soil properties and disturbance of soil native microflora. In contrast, phytoremediation is a better solution to the problem. Phytoremediation is the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is a relatively recent technology and is perceived as cost-effective, efficient, novel, eco-friendly, and solar-driven technology with good public acceptance. Phytoremediation is an area of active current research. New efficient metal hyperaccumulators are being explored for applications in phytoremediation and phytomining. Molecular tools are being used to better understand the mechanisms of metal uptake, translocation, sequestration and tolerance in plants. This review article comprehensively discusses the background, concepts and future trends in phytoremediation of heavy metals. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biochar immobilizes soil-borne arsenic but not cationic metals in the presence of low-molecular-weight organic acids.

PubMed

Alozie, Nneka; Heaney, Natalie; Lin, Chuxia

2018-07-15

A batch experiment was conducted to examine the effects of biochar on the behaviour of soil-borne arsenic and metals that were mobilized by three low-molecular-weight organic acids. In the presence of citric acid, oxalic acid and malic acid at a molar concentration of 0.01M, the surface of biochar was protonated, which disfavours adsorption of the cationic metals released from the soil by organic acid-driven mobilization. In contrast, the oxyanionic As species were re-immobilized by the protonated biochar effectively. Biochar could also immobilize oxyanionic Cr species but not cationic Cr species. The addition of biochar increased the level of metals in the solution due to the release of the biochar-borne metals under attack by LMWOAs via cation exchange. Biochar could also have the potential to enhance reductive dissolution of iron and manganese oxides in the soil, leading to enhanced release of trace elements bound to these oxides. The findings obtained from this study have implications for evaluating the role of biochar in immobilizing trace elements in rhizosphere. Adsorption of cationic heavy metals on biochar in the presence of LMWOAs is unlikely to be a mechanism responsible for the impeded uptake of heavy metals by plants growing in heavy metal-contaminated soils. Copyright © 2018 Elsevier B.V. All rights reserved.

[Study on distribution of five heavy metal elements in different parts of Cordyceps sinensis by microwave digestion ICP-MS].

PubMed

Zhou, Li; Hao, Qing-Xiu; Wang, Sheng; Yang, Quan; Kang, Chuan-Zhi; Yang, Wan-Zhen; Guo, Lan-Ping

2017-08-01

The contents of five heavy metals (Cu, Pb, As, Cd, Hg) in 17 batches of Cordyceps sinensis were determined by microwave digestion-ICP-MS, and their distribution in C. sinensis were analyzed. The results showed that the contents of Cu, Pb, Cd and Hg in all batches were in accordance with the international standards of Chinese Medicine-Chinese Herbal Medicine Heavy Metal Limit, with their contents in the stroma higher than that in the caterpillar body, and the excess rate of As, which mainly concentrated in the caterpillar body part of C. sinensis, was 88.24%, as the content of As in the caterpillar body was 7 to 12 fold of that in the stroma. In this study, the distribution of five heavy metals in C. sinensis was clarified, and the existing problems of arsenic limit of heavy metal in C. sinensis were analyzed, and some suggestions were put forward. It is hoped that the reference standard can be provided for the limited standard of arsenic in C. sinensis. Copyright© by the Chinese Pharmaceutical Association.

The function of digestive enzymes on Cu, Zn, and Pb release from soil in in vitro digestion tests.

PubMed

Li, Yi; Demisie, Walelign; Zhang, Ming-kui

2013-07-01

The bioaccessibility of soil heavy metals is the solubility of soil heavy metals in synthetic human digestive juice, which is usually determined using in vitro digestion test. To reveal the effects of digestive enzymes on soil heavy metals bioaccessibility, three representative in vitro digestion tests, Simple Bioaccessibility Extraction Test (SBET), Physiologically Based Extraction Test (PBET), and Simple Gastrointestinal Extraction Test (SGET), were chosen. The bioaccessibility of soil Cu, Zn, and Pb in each method were respectively evaluated with and without digestive enzymes, and the differences were compared. The results showed that the effects of digestive enzymes varied with different methods and elements. Because of digestive enzymes addition, the environmental change from acid gastric phase to neutral intestinal phase of PBET did not result in apparently decrease of the bioaccessibility of soil Cu. However, the solubility of soil Zn and Pb were pH-dependent. For SGET, when digestive enzymes were added, its results reflected more variations resulting from soil and element types. The impacts of digestive enzymes on heavy metal dissolution are mostly seen in the intestinal phase. Therefore, digestive enzyme addition is indispensable to the gastrointestinal digestion methods (PBET and SGET), while the pepsin addition is not important for the methods only comprised of gastric digestion (SBET).

Source apportionment of heavy metals and their ecological risk in a tropical river basin system.

PubMed

Kumar, Balwant; Singh, Umesh Kumar

2018-06-27

Surface water and sediment samples were collected from Ajay River basin to appraise the behavior of heavy metals with surrounding environments and their inter-elemental relationships. Parameters like pH and organic carbon are having a minimal role in heavy metal distribution while some elements like Fe and Cu showed great affinity for organic matter based on linear regression analysis (LRA). Ficklin diagram justified that river basin is not contaminated through acidic pollutants. The river basin is highly enriched with Cu, Cd, Pb, and Ni which were much higher than world average values, average shale standard, effect range low (ERL), and threshold effect level (TEL). PCA and LRA verified that Cu, Cd, Pb, and Ni were mainly derived from anthropogenic inputs, and others like Fe, Mn, Zn, and Co came from geogenic sources. Pollution indices revealed that river basin is moderately to highly contaminated by Cu, Cd, and Ni. Furthermore, Ajay River basin is under strong potential ecological risk based on the obtained value of risk index and probable effect level/effect range median quotient index. However, river basin is strongly influenced by lithological properties, diversified hydrogeological settings, mineralization and mobilization of subsurface materials, and urban and industrial effluents which are controlling the heavy metals.

Earliest evidence of pollution by heavy metals in archaeological sites

PubMed Central

Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

2015-01-01

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

Earliest evidence of pollution by heavy metals in archaeological sites

NASA Astrophysics Data System (ADS)

Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

2015-09-01

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

Leaching Properties of Naturally Occurring Heavy Metals from Soils

NASA Astrophysics Data System (ADS)

Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

2014-12-01

The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with remediation of naturally polluted sites, and emphasizes the importance of risk-based countermeasures against naturally occurring heavy metals. Keywords: Leaching properties, Control Factor, Naturally Occurring Heavy Metals, Lead, Arsenic, Chromium

Relationships between Heavy Metal Concentrations in Roadside Topsoil and Distance to Road Edge Based on Field Observations in the Qinghai-Tibet Plateau, China

PubMed Central

Yan, Xuedong; Gao, Dan; Zhang, Fan; Zeng, Chen; Xiang, Wang; Zhang, Man

2013-01-01

This study investigated the spatial distribution of copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), chromium (Cr), cobalt (Co), nickel (Ni) and arsenic (As) in roadside topsoil in the Qinghai-Tibet Plateau and evaluated the potential environmental risks of these roadside heavy metals due to traffic emissions. A total of 120 topsoil samples were collected along five road segments in the Qinghai-Tibet Plateau. The nonlinear regression method was used to formulize the relationship between the metal concentrations in roadside soils and roadside distance. The Hakanson potential ecological risk index method was applied to assess the degrees of heavy metal contaminations. The regression results showed that both of the heavy metals’ concentrations and their ecological risk indices decreased exponentially with the increase of roadside distance. The large R square values of the regression models indicate that the exponential regression method can suitably describe the relationship between heavy metal accumulation and roadside distance. For the entire study region, there was a moderate level of potential ecological risk within a 10 m roadside distance. However, Cd was the only prominent heavy metal which posed potential hazard to the local soil ecosystem. Overall, the rank of risk contribution to the local environments among the eight heavy metals was Cd > As > Ni > Pb > Cu > Co > Zn > Cr. Considering that Cd is a more hazardous heavy metal than other elements for public health, the local government should pay special attention to this traffic-related environmental issue. PMID:23439515

Comparison of the multifractal characteristics of heavy metals in soils within two areas of contrasting economic activities in China

NASA Astrophysics Data System (ADS)

Li, Xiaohui; Li, Xiangling; Yuan, Feng; Jowitt, Simon M.; Zhou, Taofa; Yang, Kui; Zhou, Jie; Hu, Xunyu; Li, Yang

2016-09-01

Industrial and agricultural activities can generate heavy metal pollution that can cause a number of negative environmental and health impacts. This means that evaluating heavy metal pollution and identifying the sources of these pollutants, especially in urban or developed areas, is an important first step in mitigating the effects of these contaminating but necessary economic activities. Here, we present the results of a heavy metal (Cu, Pb, Zn, Cd, As, and Hg) soil geochemical survey in Hefei city. We used a multifractal spectral technique to identify and compare the multifractality of heavy metal concentrations of soils within the industrial Daxing and agricultural Yicheng areas. This paper uses three multifractal parameters (Δα, Δf(α), and τ''(1)) to indicate the overall amount of multifractality within the soil geochemical data. The results show all of the elements barring Hg have larger Δα, Δf(α), and τ''(1) values in the Daxing area compared to the Yicheng area. The degree of multifractality suggests that the differing economic activities in Daxing and Yicheng generate very different heavy metal pollution loads. In addition, the industrial Daxing area contains significant Pb and Cd soil contamination, whereas Hg is the main heavy metal present in soils within the Yicheng area, indicating that differing clean-up procedures and approaches to remediating these polluted areas are needed. The results also indicate that multifractal modelling and the associated generation of multifractal parameters can be a useful approach in the evaluation of heavy metal pollution in soils.

Chemical and biological methods to evaluate the availability of heavy metals in soils of the Siena urban area (Italy).

PubMed

Nannoni, Francesco; Protano, Giuseppe

2016-10-15

A biogeochemistry field study was conducted in the Siena urban area (Italy) with the main objective of establishing the relationship between available amounts of heavy metals in soil assessed by a chemical method (soil fractionation) and bioavailability assessed by a biological method (bioaccumulation in earthworm tissues). The total content of traffic-related (Cd, Cu, Pb, Sb, Zn) and geogenic (Co, Cr, Ni, U) heavy metals in uncontaminated and contaminated soils and their concentrations in soil fractions and earthworms were used for this purpose. The bioavailability of heavy metals assessed by earthworms did not always match the availability defined by soil fractionation. Earthworms were a good indicator to assess the bioavailability of Pb and Sb in soil, while due to physiological mechanisms of regulation and excretion, Cd, Cu and Zn tissue levels in these invertebrates gave misleading estimates of their bioavailable pool. No relationship was identified between chemical and biological availability for the geogenic heavy metals, characterized by a narrow range of total contents in soil. The study highlighted that chemical and biological methods should be combined to provide more complete information about heavy element bioavailability in soils. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of the suitability of two lichen species and one higher plant for monitoring airborne heavy metals.

PubMed

Aprile, Giuseppa Grazia; Di Salvatore, Mina; Carratù, Giovanna; Mingo, Antonio; Carafa, Anna Maria

2010-03-01

We compared the capacity to accumulate airborne heavy metals of two lichens (Flavoparmelia caperata and Parmotrema chinense) and one higher plant (Nerium oleander) at a very densely populated urban site near Naples. After 15, 45, 75, and 120 days of exposure at four sites with different levels of air pollution, equal portions of thalli and 20 leaves were collected, and four environmentally significant elements, Fe, Cu, Zn, and Pb, were measured by inductively coupled plasma analysis. To compare the accumulation rates of lichens and the vascular plant, we determined an index of relative accumulation rate of pollutants during time and the ratio between the concentrations of each element in exposed samples to that of control samples (exposed-to-control ratio). Our data indicate F. caperata as being the most suitable bioaccumulator, followed by P. chinense. N. oleander was also found to be a useful heavy metal biomonitor though not suitable as a bioaccumulator.

Benefits of the Use of Sewage Sludge over EDTA to Remediate Soils Polluted with Heavy Metals.

PubMed

Hernández, Ana J; Gutiérrez-Ginés, María J; Pastor, Jesús

2015-09-01

Sewage sludges from urban wastewater treatment plants are often used to remediate degraded soils. However, the benefits of their use in metal-polluted soils remain unclear and need to be assessed in terms of factors besides soil fertility. This study examines the use of thermal-dried sewage sludge (TDS) as an amendment for heavy metal-polluted soil in terms of its effects on soil chemical properties, leachate composition, and the growth of native plant communities. To assess the response of the soil and its plant community to an increase in metal mobilization, the effects of TDS amendment were compared with those of the addition of a chelating agent (ethylenediaminetetraacetic acid [EDTA]). The experimental design was based on a real-case scenario in which soils from of an abandoned mine site were used in a greenhouse bioassay. Two doses of TDS and EDTA were applied to a soil containing high Pb, Zn, Cu, and Cd levels (4925, 5675, 404, and 25 mg kg, respectively). Soil pH was 6.4, and its organic matter content was 5.53%. The factors examined after soil amendment were soil fertility and heavy metal contents, leachate element losses, the plant community arising from the seed bank (plant cover, species richness and biodiversity, above/below ground biomass), and phytotoxic effects (chemical contents of abundant species). Thermal-dried sewage sludge emerged as a good phytostabilizer of Pb, Zn, Cu, and Cd given its capacity to reduce the plant uptake of metals and achieve rapid plant cover. This amendment also enhanced the retention of other elements in the plant root system and overall showed a better capacity to remediate soils polluted with several heavy metals. The addition of EDTA led to plant productivity losses and nutritional imbalances because it increased the mobility of several elements in the soil and its leachates. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Marine sponges with contrasting life histories can be complementary biomonitors of heavy metal pollution in coastal ecosystems.

PubMed

Batista, Daniela; Muricy, Guilherme; Rocha, Rafael Chávez; Miekeley, Norbert F

2014-05-01

In this study, we compared the usefulness of a long-living sponge (Hymeniacidon heliophila, Class Demospongiae) and a short-living one (Paraleucilla magna, Class Calcarea) as biomonitors of metallic pollution. The concentrations of 16 heavy metals were analyzed in both species along a gradient of decreasing pollution from the heavily polluted Guanabara Bay to the less impacted coastal islands in Rio de Janeiro, SE Brazil (SW Atlantic). The levels of most elements analyzed were higher in H. heliophila (Al, Co, Cr, Cu, Fe, Mn, Ni, Hg, Ni, and Sn) and P. magna (Ni, Cu, Mn, Al, Ti, Fe, Pb, Co, Cr, Zn, and V) collected from the heavily polluted bay when compared with the cleanest sites. Hymeniacidon heliophila accumulates 11 elements more efficiently than P. magna. This difference may be related to their skeleton composition, histological organization, symbiont bacteria and especially to their life cycle. Both species can be used as a biomonitors of metallic pollution, but while Hymeniacidon heliophila was more effective in concentrating most metals, Paraleucilla magna is more indicated to detect recent pollutant discharges due to its shorter life cycle. We suggest that the complementary use of species with contrasting life histories can be an effective monitoring strategy of heavy metals in coastal environments.

Heavy metals concentration and availability of different soils in Sabzevar area, NE of Iran

NASA Astrophysics Data System (ADS)

Mazhari, Seyed Ali; Sharifiyan Attar, Reza; Haghighi, Faezeh

2017-10-01

Soils developed in the Sabzevar ophiolitic area originate from different bedrocks. All samples display similar physico-chemical properties, but heavy metal concentrations vary extremely in different soil samples. Serpentine soils have the highest total concentration of Cr, Ni and Co; while soils derived from mafic rocks (olivine basalts and hornblende gabbros) show the highest Cu (85.29-109.11 ppm) and Zn (46.88-86.60 ppm). The DTPA-extraction of soil samples indicates that the order of metal bioavailability was Cr3% of total Cr; >12% of total Co and >17% of total Zn). Oxide minerals (such as chromite and magnetite) in Sabzevar soils play as resistant minerals and impede the heavy metal availability; while forsterite, pyroxene, serpentine and talc are more labile and show higher DTPA-extractable of heavy metals.

An Assessment of Heavy Metal Contamination on the Surface Sediment of Seagrass Beds at the Khanh Hoa Coast, Vietnam.

PubMed

Nguyen, Xuan-Vy; Tran, Minh-Hue; Le, Trong-Dung; Papenbrock, Jutta

2017-12-01

Seagrasses beds are vulnerable ecosystems. Human-induced disturbances, including heavy metal pollution, cause losses in seagrass beds. Assessment of the heavy metal concentration in seagrass meadows is an urgent need in order to protect and sustain these ecosystems. The concentration of eight trace metals in the surface sediment was observed from six seagrass beds at Khanh Hoa's coast, Vietnam. Three pollution indices and statistical analysis were used to evaluate the levels of contamination with these elements. This report on heavy metals within seagrass beds in Vietnam shows that, based on enrichment factors, only one location revealed moderately severe enrichment of Cu. Geo-accumulation indices fall in the uncontaminated class at all locations whereas for the ecological risk factor, values of Cu at My Giang and of Pb at Thuy Trieu were in a moderate risk class. Hence, two of eight locations may be exposed to high Cu and Pb.

[Mapping Critical Loads of Heavy Metals for Soil Based on Different Environmental Effects].

PubMed

Shi, Ya-xing; Wu, Shao-hua; Zhou, Sheng-lu; Wang, Chun-hui; Chen, Hao

2015-12-01

China's rapid development of industrialization and urbanization causes the growing problem of heavy metal pollution of soil, threatening environment and human health. Therefore, prevention and management of heavy metal pollution become particularly important. Critical loads of heavy metals are an important management tool that can be utilized to prevent the occurrence of heavy metal pollution. Our study was based on three cases: status balance, water environmental effects and health risks. We used the steady-state mass balance equation to calculate the critical loads of Cd, Cu, Pb, Zn at different effect levels and analyze the values and spatial variation of critical loads. In addition, we used the annual input fluxes of heavy metals of the agro-ecosystem in the Yangtze River delta and China to estimate the proportion of area with exceedance of critical loads. The results demonstrated that the critical load value of Cd was the minimum, and the values of Cu and Zn were lager. There were spatial differences among the critical loads of four elements in the study area, lower critical loads areas mainly occurred in woodland and high value areas distributed in the east and southwest of the study area, while median values and the medium high areas mainly occurred in farmland. Comparing the input fluxes of heavy metals, we found that Pb and Zn in more than 90% of the area exceeded the critical loads under different environmental effects in the study area. The critical load exceedance of Cd mainly occurred under the status balance and the water environmental effect, while Cu under the status balance and water environmental effect with a higher proportion of exceeded areas. Critical loads of heavy metals at different effect levels in this study could serve as a reference from effective control of the emissions of heavy metals and to prevent the occurrence of heavy metal pollution.

Heavy metal biomonitoring and phytoremediation potentialities of aquatic macrophytes in River Nile.

PubMed

Fawzy, Manal Ahmed; Badr, Nadia El-sayed; El-Khatib, Ahmed; Abo-El-Kassem, Amany

2012-03-01

The concentrations of Cd, Cu, Pb, and Zn in sediments, water, and different plant organs of six aquatic vascular plant species, Ceratophyllum demersum L. Echinochloa pyramidalis (Lam.) Hitchc. & Chase; Eichhornia crassipes (Mart.) Solms-Laub; Myriophyllum spicatum L.; Phragmites australis (Cav.) Trin. ex Steud; and Typha domingensis (Pers.) Poir. ex Steud, growing naturally in the Nile system (Sohag Governorate), were investigated. The aim was to define which species and which plant organs exhibit the greatest accumulation and evaluate whether these species could be usefully employed in biomonitoring and phytoremediation programs. The recorded metals in water samples were above the standard levels of both US Environmental Protection Agency and Egyptian Environmental Affairs Agency except for Pb. The concentrations of heavy metals in water, sediments, and plants possess the same trend: Zn > Cu > Pb > Cd which reflects the biomonitoring potentialities of the investigated plant species. Generally, the variation of heavy element concentrations in water and sediments in relation to site and season, as assessed by two-way repeated measured ANOVA, was significant (p < 0.05). However, insignificant variations were observed in the concentrations of Pb and Cd in sediments in relation to season and of Cu and Zn in relation to site. Results also showed that the selectivity of the heavy elements for the investigated plants varied significantly (p < 0.05) with species variation. The accumulation capability of the investigated species could be arranged according to this pattern: C. demersum > E. crassipes > M. spicatum > E. pyramidalis > T. domingensis > P. australis. On the basis of the element concentrations, roots of all the studied species contain higher concentrations of Cu and Zn than shoots while leaves usually acquire the highest concentrations of Pb. Cd concentrations among different plant organs are comparable except in M. spicatum where the highest Cd concentrations were recorded in the leaves. Our results also demonstrated that all the studied species can accumulate more than 1,450-fold the concentration of the investigated heavy elements in water rendering them of interest for use in phytoremediation studies of polluted waters. Given the absence of systematic water quality monitoring, heavy elements in plants, rather than sediments, provide a cost-effective means for assessing heavy element accumulation in aquatic systems during plant organ lifespan.

Efficiency Evaluation of Food Waste Materials for the Removal of Metals and Metalloids from Complex Multi-Element Solutions

PubMed Central

Giuliano, Antonella; Astolfi, Maria Luisa; Congedo, Rossana; Masotti, Andrea; Canepari, Silvia

2018-01-01

Recent studies have shown the potential of food waste materials as low cost adsorbents for the removal of heavy metals and toxic elements from wastewater. However, the adsorption experiments have been performed in heterogeneous conditions, consequently it is difficult to compare the efficiency of the individual adsorbents. In this study, the adsorption capacities of 12 food waste materials were evaluated by comparing the adsorbents’ efficiency for the removal of 23 elements from complex multi-element solutions, maintaining homogeneous experimental conditions. The examined materials resulted to be extremely efficient for the adsorption of many elements from synthetic multi-element solutions as well as from a heavy metal wastewater. The 12 adsorbent surfaces were analyzed by Fourier transform infrared spectroscopy and showed different types and amounts of functional groups, which demonstrated to act as adsorption active sites for various elements. By multivariate statistical computations of the obtained data, the 12 food waste materials were grouped in five clusters characterized by different elements’ removal efficiency which resulted to be in correlation with the specific adsorbents’ chemical structures. Banana peel, watermelon peel and grape waste resulted the least selective and the most efficient food waste materials for the removal of most of the elements. PMID:29495363

HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance.

PubMed

Wakeford, Hannah R; Sing, David K; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D; Tremblin, Pascal; Amundsen, David S; Lewis, Nikole K; Mandell, Avi M; Fortney, Jonathan J; Knutson, Heather; Benneke, Björn; Evans, Thomas M

2017-05-12

A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H 2 O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b's atmospheric heavy element content ([Formula: see text] times solar). This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals. Copyright © 2017, American Association for the Advancement of Science.

The impact of heavy metals from environmental tobacco smoke on indoor air quality as determined by Compton suppression neutron activation analysis.

PubMed

Landsberger, S; Wu, D

1995-12-01

The method of instrumental neutron activation analysis (NAA) has been improved for air filter samples in the determination of low level heavy metals in indoor air. By using the techniques of epithermal neutron irradiation in conjunction with Compton suppression, the detection limits of cadmium, arsenic and antimony measurements have been dramatically reduced to 2 ng for Cd, 0.2 ng for As, and 0.03 ng for Sb. The determination of these heavy metals in particulate material generated from cigarette smoking in indoor environments has been conducted. Other elements, Br, Cl, Na, K, Zn were also found at elevated levels.

[Hyperspectral remote sensing in monitoring the vegetation heavy metal pollution].

PubMed

Li, Na; Lü, Jian-sheng; Altemann, W

2010-09-01

Mine exploitation aggravates the environment pollution. The large amount of heavy metal element in the drainage of slag from the mine pollutes the soil seriously, doing harm to the vegetation growing and human health. The investigation of mining environment pollution is urgent, in which remote sensing, as a new technique, helps a lot. In the present paper, copper mine in Dexing was selected as the study area and China sumac as the study plant. Samples and spectral data in field were gathered and analyzed in lab. The regression model from spectral characteristics for heavy metal content was built, and the feasibility of hyperspectral remote sensing in environment pollution monitoring was testified.

Source apportionment of atmospheric bulk deposition in the Belgrade urban area using Positive Matrix factorization

NASA Astrophysics Data System (ADS)

Tasić, M.; Mijić, Z.; Rajšić, S.; Stojić, A.; Radenković, M.; Joksić, J.

2009-04-01

The primary objective of the present study was to assess anthropogenic impacts of heavy metals to the environment by determination of total atmospheric deposition of heavy metals. Atmospheric depositions (wet + dry) were collected monthly, from June 2002 to December 2006, at three urban locations in Belgrade, using bulk deposition samplers. Concentrations of Fe, Al, Pb, Zn, Cu, Ni, Mn, Cr, V, As and Cd were analyzed using atomic absorption spectrometry. Based upon these results, the study attempted to examine elemental associations in atmospheric deposition and to elucidate the potential sources of heavy metal contaminants in the region by the use of multivariate receptor model Positive Matrix Factorization (PMF).

Online X-ray Fluorescence (XRF) Analysis of Heavy Metals in Pulverized Coal on a Conveyor Belt.

PubMed

Yan, Zhang; XinLei, Zhang; WenBao, Jia; Qing, Shan; YongSheng, Ling; DaQian, Hei; Da, Chen

2016-02-01

Heavy metals in haze episode will continue to threaten the quality of public health around the world. In order to decrease the emission of heavy metals produced from coal burning, an online X-ray fluorescence (XRF) analyzer system, consisting of an XRF analyzer with data acquisition software and a laser rangefinder, was developed to carry out the measurement of heavy metals in pulverized coal. The XRF analyzer was mounted on a sled, which can effectively smooth the surface of pulverized coal and reduce the impact of surface roughness during online measurement. The laser rangefinder was mounted over the sled for measuring the distance between a pulverized coal sample and the analyzer. Several heavy metals and other elements in pulverized coal were online measured by the XRF analyzer directly above a conveyor belt. The limits of detection for Hg, Pb, Cr, Ti, Fe, and Ca by the analyzer were 44 ± 2, 34 ± 2, 17 ± 3, 41 ± 4, 19 ± 3, and 65 ± 2 mg·kg(-1), respectively. The relative standard deviation (%RSD) for the elements mentioned was less than 7.74%. By comparison with the results by inductively-coupled plasma mass spectrometry (ICP-MS), relative deviation (%D) of the online XRF analyzer was less than 10% for Cr, Ti, and Ca, in the range of 0.8-24.26% for Fe, and greater than 20% for Hg and Pb. © The Author(s) 2016.

The use of vegetables in the biomonitoring of cadmium and lead pollution in the environment.

PubMed

Szczygłowska, Marzena; Bodnar, Małgorzata; Namieśnik, Jacek; Konieczka, Piotr

2014-01-01

Lead and cadmium emitted from various anthropogenic sources have the ability to accumulate in tissues of living organisms. The phenomenon of accumulation of metals in the body is harmful and undesirable. The ability of plants to accumulate heavy metals from the individual elements of the environment has been used in biomonitoring of pollution. Leaves and roots of vegetables have particular predisposition for accumulating toxic metals such as lead and cadmium and therefore can be used for biomonitoring of the environment, mainly as a tool for assessing the extent of soil contamination. The article discusses information in the literature on entry paths of lead and cadmium into the body, toxic effects of lead and cadmium on the human organism, and the use of vegetables as a tool in the biomonitoring of heavy metals in different elements of the environment.

Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Topical report. [Metal content in Cerro Negro heavy petroleum

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

Pearson, C.D.; Green, J.A.; Green, J.B.

1988-01-01

Nickel, vanadium, and iron were determined in distilled and chromatographically separated fractions from Cerro Negro heavy petroleum. Corresponding data were also obtained on two samples of Wilmington, California, heavy crude and one Mayan, Mexico, heavy oil for comparison. For the Cerro Negro crude, the ratio of porphyrinic to nonporphyrinic forms of metals was also determined on selected fractions using visible spectroscopy. In all four heavy petroleums, significant levels of metals were found only in the highest boiling distillate available, ca. 550-700/sup 0/C (1000-1300/sup 0/F), and the residue. Typically, the distillation residue contained >95 percent of a given metal. All crudesmore » contained metalloorganics of the following types: strongly acidic, weakly acidic, strongly basic, weakly basic, and neutral, but the relative distribution of metals among each class was crude dependent. Generally, nickel and vanadium distributions for a given crude followed one another very closely, while those for iron were often inconclusive because of poor mass balances for that element. Attempts to concentrate metalloorganics through liquid chromatographic separation methods largely unsuccessful. The wide variety of types of metal-containing compounds in the crudes examined precluded the use of a single approach for their isolation or preconcentration. 21 refs., 1 fig., 12 tabs.« less

Geostatistical conditional simulation for the assessment of contaminated land by abandoned heavy metal mining.

PubMed

Ersoy, Adem; Yunsel, Tayfun Yusuf; Atici, Umit

2008-02-01

Abandoned mine workings can undoubtedly cause varying degrees of contamination of soil with heavy metals such as lead and zinc has occurred on a global scale. Exposure to these elements may cause to harm human health and environment. In the study, a total of 269 soil samples were collected at 1, 5, and 10 m regular grid intervals of 100 x 100 m area of Carsington Pasture in the UK. Cell declustering technique was applied to the data set due to no statistical representativity. Directional experimental semivariograms of the elements for the transformed data showed that both geometric and zonal anisotropy exists in the data. The most evident spatial dependence structure of the continuity for the directional experimental semivariogram, characterized by spherical and exponential models of Pb and Zn were obtained. This study reports the spatial distribution and uncertainty of Pb and Zn concentrations in soil at the study site using a probabilistic approach. The approach was based on geostatistical sequential Gaussian simulation (SGS), which is used to yield a series of conditional images characterized by equally probable spatial distributions of the heavy elements concentrations across the area. Postprocessing of many simulations allowed the mapping of contaminated and uncontaminated areas, and provided a model for the uncertainty in the spatial distribution of element concentrations. Maps of the simulated Pb and Zn concentrations revealed the extent and severity of contamination. SGS was validated by statistics, histogram, variogram reproduction, and simulation errors. The maps of the elements might be used in the remediation studies, help decision-makers and others involved in the abandoned heavy metal mining site in the world.

Source apportionment and pollution evaluation of heavy metals in water and sediments of Buriganga River, Bangladesh, using multivariate analysis and pollution evaluation indices.

PubMed

Bhuiyan, Mohammad Amir Hossain; Dampare, Samuel B; Islam, M A; Suzuki, Shigeyuki

2015-01-01

Concentrations of heavy metals in water and sediment samples of Buriganga River in the capital city Dhaka, Bangladesh, were studied to understand the level of heavy metals and their source apportionment. The results showed that the mean concentrations of heavy metals both in water and sediment samples were very high and, in most cases, exceeded the permissible limits recommended by the Bangladesh government and other international organizations. Significantly higher concentrations of Pb, Cr, Mn, Co, Ni, Cu, Zn, As, and Cd were found in sediment samples. However, average concentrations of metals both in water and sediment samples were above the effect range median. The heavy metal pollution index (HPI) and degree of contamination (Cd) yielded different results in water samples despite significant correlations between them. The heavy metal evaluation index (HEI) showed strong correlations with HPI and Cd and provided better assessment of pollution levels. The enrichment factor (EF) and geoaccumulation index (Igeo) showed the elevated value of Cr, Pb, and Cd in access of background values. The measured elements were subjected to positive matrix factorization (PMF) and examining correlations in order to explain the content, behavior, and source apportionment of metals. PMF resulted in a successful partitioning of variances into sources related to background geochemistry and contaminant influences. However, the PMF approach successfully demarcated the major sources of metals from tannery, paint, municipal sewage, textiles, and agricultural activities.

Metal transformation as a strategy for bacterial detoxification of heavy metals.

PubMed

Essa, Ashraf M M; Al Abboud, Mohamed A; Khatib, Sayeed I

2018-01-01

Microorganisms can modify the chemical and physical characters of metals leading to an alteration in their speciation, mobility, and toxicity. Aqueous heavy metals solutions (Hg, Cd, Pb, Ag, Cu, and Zn) were treated with the volatile metabolic products (VMPs) of Escherichia coli Z3 for 24 h using aerobic bioreactor. The effect of the metals treated with VMPs in comparison to the untreated metals on the growth of E. coli S1 and Staphylococcus aureus S2 (local isolates) was examined. Moreover, the toxic properties of the treated and untreated metals were monitored using minimum inhibitory concentration assay. A marked reduction of the treated metals toxicity was recorded in comparison to the untreated metals. Scanning electron microscopy and energy dispersive X-ray analysis revealed the formation of metal particles in the treated metal solutions. In addition to heavy metals at variable ratios, these particles consisted of carbon, oxygen, sulfur, nitrogen elements. The inhibition of metal toxicity was attributed to the existence of ammonia, hydrogen sulfide, and carbon dioxide in the VMPs of E. coli Z3 culture that might responsible for the transformation of soluble metal ions into metal complexes. This study clarified the capability of E. coli Z3 for indirect detoxification of heavy metals via the immobilization of metal ions into biologically unavailable species. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Association between heavy metal and metalloid levels in topsoil and cancer mortality in Spain.

PubMed

Núñez, Olivier; Fernández-Navarro, Pablo; Martín-Méndez, Iván; Bel-Lan, Alejandro; Locutura Rupérez, Juan F; López-Abente, Gonzalo

2017-03-01

Spatio-temporal cancer mortality studies in Spain have revealed patterns for some tumours which display a distribution that is similar across the sexes and persists over time. Such characteristics would be common to tumours that shared risk factors, including the geochemical composition of the soil. The aim of this study was to assess the possible association between heavy metal and metalloid levels in topsoil (upper soil horizon) and cancer mortality in mainland Spain. Ecological cancer mortality study at a municipal level, covering 861,440 cancer deaths (27 different tumour locations) in 7917 Spanish mainland towns, from 1999 to 2008. The elements included in this analysis were Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Topsoil levels (partial extraction) were determined by ICP-MS at 13,317 sampling points. For the analysis, the data on the topsoil composition have been transformed by the centred logratio (clr-transformation). Principal factor analysis was performed to obtain independent latent factors for the transformed variables. To estimate the effect of heavy metal levels in topsoil composition on mortality, we fitted Besag, York and Mollié models, which included each town's factor scores as the explanatory variable. Integrated Nested Laplace Approximation (INLA) was used as a tool for Bayesian inference. All results were adjusted for sociodemographic variables. The results showed an association between trace contents of heavy metals and metalloids in topsoil and mortality due to tumours of the digestive system in mainland Spain. This association was observed in both sexes, something that would support the hypothesis that the incorporation of heavy metals into the trophic chain might be playing a role in the aetiology of some types of cancer. Topsoil composition and the presence of potentially toxic elements in trace concentrations might be an additional component in the aetiology of some types of cancer, and go some way to determine the ensuing geographic differences in mortality in Spain. The results support the interest of inclusion of heavy metal levels in topsoil as a hypothesis in analytical epidemiological studies using biological markers of exposure to heavy metals and metalloids.

Probing single magnon excitations in Sr₂IrO₄ using O K-edge resonant inelastic x-ray scattering.

PubMed

Liu, X; Dean, M P M; Liu, J; Chiuzbăian, S G; Jaouen, N; Nicolaou, A; Yin, W G; Rayan Serrao, C; Ramesh, R; Ding, H; Hill, J P

2015-05-27

Resonant inelastic x-ray scattering (RIXS) at the L-edge of transition metal elements is now commonly used to probe single magnon excitations. Here we show that single magnon excitations can also be measured with RIXS at the K-edge of the surrounding ligand atoms when the center heavy metal elements have strong spin-orbit coupling. This is demonstrated with oxygen K-edge RIXS experiments on the perovskite Sr2IrO4, where low energy peaks from single magnon excitations were observed. This new application of RIXS has excellent potential to be applied to a wide range of magnetic systems based on heavy elements, for which the L-edge RIXS energy resolution in the hard x-ray region is usually poor.

Impact of industrial effluent on growth and yield of rice (Oryza sativa L.) in silty clay loam soil.

PubMed

Anwar Hossain, Mohammad; Rahman, Golum Kibria Muhammad Mustafizur; Rahman, Mohammad Mizanur; Molla, Abul Hossain; Mostafizur Rahman, Mohammad; Khabir Uddin, Mohammad

2015-04-01

Degradation of soil and water from discharge of untreated industrial effluent is alarming in Bangladesh. Therefore, buildup of heavy metals in soil from contaminated effluent, their entry into the food chain and effects on rice yield were quantified in a pot experiment. The treatments were comprised of 0, 25%, 50%, 75% and 100% industrial effluents applied as irrigation water. Effluents, initial soil, different parts of rice plants and post-harvest pot soil were analyzed for various elements, including heavy metals. Application of elevated levels of effluent contributed to increased heavy metals in pot soils and rice roots due to translocation effects, which were transferred to rice straw and grain. The results indicated that heavy metal toxicity may develop in soil because of contaminated effluent application. Heavy metals are not biodegradable, rather they accumulate in soils, and transfer of these metals from effluent to soil and plant cells was found to reduce the growth and development of rice plants and thereby contributed to lower yield. Moreover, a higher concentration of effluent caused heavy metal toxicity as well as reduction of growth and yield of rice, and in the long run a more aggravated situation may threaten human lives, which emphasizes the obligatory adoption of effluent treatment before its release to the environment, and regular monitoring by government agencies needs to be ensured. Copyright © 2015. Published by Elsevier B.V.

Evaluation of heavy metals in hazardous automobile shredder residue thermal residue and immobilization with novel nano-size calcium dispersed reagent.

PubMed

Lee, Chi-Hyeon; Truc, Nguyen Thi Thanh; Lee, Byeong-Kyu; Mitoma, Yoshiharu; Mallampati, Srinivasa Reddy

2015-10-15

This study was conducted to synthesize and apply a nano-size calcium dispersed reagent as an immobilization material for heavy metal-contaminated automobile shredder residues (ASR) dust/thermal residues in dry condition. Simple mixing with a nanometallic Ca/CaO/PO4 dispersion mixture immobilized 95-100% of heavy metals in ASR dust/thermal residues (including bottom ash, cavity ash, boiler and bag filter ash). The quantity of heavy metals leached from thermal residues after treatment by nanometallic Ca/CaO/PO4 was lower than the Korean standard regulatory limit for hazardous waste landfills. The morphology and elemental composition of the nanometallic Ca/CaO-treated ASR residue were characterized by field emission scanning election microscopy combined with electron dispersive spectroscopy (FE-SEM/EDS). The results indicated that the amounts of heavy metals detectable on the ASR thermal residue surface decreased and the Ca/PO4 mass percent increased. X-ray diffraction (XRD) pattern analysis indicated that the main fraction of enclosed/bound materials on ASR residue included Ca/PO4- associated crystalline complexes, and that immobile Ca/PO4 salts remarkably inhibited the desorption of heavy metals from ASR residues. These results support the potential use of nanometallic Ca/CaO/PO4 as a simple, suitable and highly efficient material for the gentle immobilization of heavy metals in hazardous ASR thermal residue in dry condition. Copyright © 2015 Elsevier B.V. All rights reserved.

Heavy metals (Pb, Cd, As and MeHg) as risk factors for cognitive dysfunction: A general review of metal mixture mechanism in brain.

PubMed

Karri, Venkatanaidu; Schuhmacher, Marta; Kumar, Vikas

2016-12-01

Human exposure to toxic heavy metals is a global challenge. Concurrent exposure of heavy metals, such as lead (Pb), cadmium (Cd), arsenic (As) and methylmercury (MeHg) are particularly important due to their long lasting effects on the brain. The exact toxicological mechanisms invoked by exposure to mixtures of the metals Pb, Cd, As and MeHg are still unclear, however they share many common pathways for causing cognitive dysfunction. The combination of metals may produce additive/synergetic effects due to their common binding affinity with NMDA receptor (Pb, As, MeHg), Na + - K + ATP-ase pump (Cd, MeHg), biological Ca +2 (Pb, Cd, MeHg), Glu neurotransmitter (Pb, MeHg), which can lead to imbalance between the pro-oxidant elements (ROS) and the antioxidants (reducing elements). In this process, ROS dominates the antioxidants factors such as GPx, GS, GSH, MT-III, Catalase, SOD, BDNF, and CERB, and finally leads to cognitive dysfunction. The present review illustrates an account of the current knowledge about the individual metal induced cognitive dysfunction mechanisms and analyse common Mode of Actions (MOAs) of quaternary metal mixture (Pb, Cd, As, MeHg). This review aims to help advancement in mixture toxicology and development of next generation predictive model (such as PBPK/PD) combining both kinetic and dynamic interactions of metals. Copyright © 2016 Elsevier B.V. All rights reserved.

Elemental characterization of Mt. Sinabung volcanic ash, Indonesia by Neutron Activation Analysis

NASA Astrophysics Data System (ADS)

Kusmartini, I.; Syahfitri, W. Y. N.; Kurniawati, S.; Lestiani, D. D.; Santoso, M.

2017-06-01

Mount Sinabung is a volcano located in North Sumatera, Indonesia which has been recorded not erupted since 1600. However in 2013 it has been erupted and cause of black thick smog, rain sand and volcanic ash. Volcanic ash containing trace elements material that can be utilized in various applications but still has potential danger of heavy metals. In order to obtain an elemental composition data of volcanic ash, the characterization of volcanic ash were carried out using Neutron Activation Analysis. The volcanic ash was taken from Mt. Sinabung eruption. Samples were irradiated at the rabbit system in the reactor G.A Siwabessy facilities with neutron flux ˜ 1013 n.cm-2.s-1 and then counted using HPGe detector. Method validation was carried out by SRM NIST Coal Fly Ash 1633b and NIST 2711a Montana II Soil with recovery values were in the range of 96-108% and 95-106% respectively. The results showed that major elements; Al, Na, Ca and Fe, concentrations were 8.7, 1.05, 2.98 and 7.44 %, respectively, minor elements K, Mg, Mn, Ti, V and Zn were 0.87%, 0.78%, 0.18%, 0.62%, 197.13 ppm and 109.35 ppm, respectively, heavy metals; As, Cr, Co and Sb, contents were 4.48, 11.75, 17.13 and 0.35 ppm, respectively while rare earth elements such as Ce, Eu, La, Nd, Sm, Yb were 45.33, 1.22, 19.63, 20.34, 3.86, and 2.57 ppm respectively. The results of the elemental contents of volcanic ash that has been obtained can be used as the scientific based data for volcanic material utilization by considering the economic potential of elements contained and also the danger of the heavy metals content.

Treatment Technologies for Historical Ponds Containing Elemental Phosphorus - Summary and Evaluation

EPA Pesticide Factsheets

This report provides a summary and evaluation on six remediation technologies potentially applicable to treat 16 ponds containing waste contaminated with elemental phosphorus, heavy metals, and radiocnuclides at the Eastern Michaud Flats (EMF) Superfund...

Effects of elemental sulphur on heavy metal uptake by plants growing on municipal sewage sludge.

PubMed

Dede, Gulgun; Ozdemir, Saim

2016-01-15

In this study experiment was carried out to determine the phytoextraction potential of six plant species (Conium maculatum, Brassica oleraceae var. oleraceae, Brassica juncea, Datura stramonium, Pelargonium hortorum and Conyza canadensis) grown in a sewage sludge medium amended with metal uptake promoters. The solubility of Cu, Cd and Pb was significantly increased with the application of elemental S due to decrease of pH. Faecal coliform number was markedly decreased by addition of elemental sulphur. The extraction of Cu, Cr and Pb from sewage sludge by using B. juncea plant was observed as 65%, 65% and 54% respectively that is statistically similar to EDTA as sulphur. The bioaccumulation factors were found higher (>1) in the plants tested for Cu and Pb like B. juncea. Translocation index (TI) calculated values for Cd and Pb were greater than one (>1) in both C. maculatum and B. oleraceae var. oleraceae. The results cleared that the amendment of sludge with elemental sulphur showed potential to solubilize heavy metals in phytoremediation as much as EDTA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Background concentrations and reference values for heavy metals in soils of Cuba.

PubMed

Alfaro, Mirelys Rodríguez; Montero, Alfredo; Ugarte, Olegario Muñiz; do Nascimento, Clístenes Williams Araújo; de Aguiar Accioly, Adriana Maria; Biondi, Caroline Miranda; da Silva, Ygor Jacques Agra Bezerra

2015-01-01

The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg(-1)): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements.

Geochemical background and ecological risk of heavy metals in surface sediments from the west Zhoushan Fishing Ground of East China Sea.

PubMed

Xu, Gang; Liu, Jian; Pei, Shaofeng; Hu, Gang; Kong, Xianghuai

2015-12-01

Surface sediment grain size as well as the spatial distribution, pollution status, and source identification of heavy metals in the west Zhoushan Fishing Ground (ZFG) of the East China Sea were analyzed to study the geochemical background concentrations of heavy metals and to assess their potential ecological risk. Our results show that surface sediments in the eastern part of study area were mainly composed of sand-sized components. Spatial distributions of heavy metals were mainly controlled by grain size and terrigenous materials, and their concentrations in the coarsest grain sediments formed primarily during the Holocene transgressive period could represent the element background values of our study area. Contamination factor suggests that there was no pollution of Pb, Zn, and Cr generally in our study area and slight pollution of Cu, Cd, and As (especially Cu) at some stations. In addition, ecological harm coefficient indicates that the ecological risk of each heavy metal, except for Cd, at two stations was low as well. These results are consistent with the pollution load index and ecological risk index, which suggest both the overall level of pollution and the overall ecological risk of six studied metals in sediment were relatively low in our study area. Enrichment factor indicates that the heavy metals came mostly from the natural source. Summarily, the quality level of sediment in our study area was relatively good, and heavy metals in sediments could not exert threat to aquatic lives in the ZFG until now.

Adsorption of Heavy Metals in Industrial Wastewater by Magnetic Nano-particles

NASA Astrophysics Data System (ADS)

Tu, Y.; You, C.

2010-12-01

Industrial wastewater containing heavy metals is of great concern because of their toxic impact to living species and environments. Removal of metal ions from industrial effluent using nano-particles is an area of extensive research. This study collected wastewaters and effluents from 11 industrial companies in tanning, electronic plating, printed circuit board manufacturing, semi-conductor, and metal surface treatment industry and studied in detailed the major and trace element compositions to develop potential fingerprinting technique for pollutant source identification. The results showed that electronic plating and metal surface treatment industry produce high Fe, Mn, Cr, Zn, Ni and Mo wastewater. The tanning industry and the printed circuit board manufacturing industry released wastewater with high Fe and Cr, Cu and Ni, respectively. For semi-conductor industry, significant dissolved In was detected in wastewater. The absorption experiments to remove heavy metals in waters were conducted using Fe3O4 nano-particles. Under optimal conditions, more than 99 % dissolved metals were removed in a few minutes.

Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China.

PubMed

Hu, Rong; Yan, Yun; Zhou, Xiaoli; Wang, Yanan; Fang, Yanming

2018-02-22

Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr), copper (Cu), lead (Pb), vanadium (V), and zinc (Zn)) at five sampling sites (four roads and a forest park) during the summer and winter of 2012. According to the relative accumulation factor (RAF) and contamination factor (CF) results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation ( p < 0.05) between traffic volume and concentration for three heavy metals (Cr, Cu, and V) in winter, whereas a significant positive correlation ( p < 0.05) was observed between traffic volume and concentrations for four heavy metal elements (Cr, Pb, V, and Zn) in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution.

Multivariate geostatistical analysis and source identification of heavy metals in the sediment of Poyang Lake in China.

PubMed

Dai, Lijun; Wang, Lingqing; Li, Lianfang; Liang, Tao; Zhang, Yongyong; Ma, Chuanxin; Xing, Baoshan

2018-04-15

Heavy metals in lake sediment have become a great concern because their remobilization has frequently occurred under hydrodynamic disturbance in shallow lakes. In this study, heavy metals (Cr, Cu, Cd, Pb, and Zn) concentrations in the surface and core sediments of the largest freshwater lake in China, Poyang Lake, were investigated. Geostatistical prediction maps of heavy metals distribution in the surface sediment were completed as well as further data mining. Based on the prediction maps, the ranges of Cr, Cu, Cd, Pb, and Zn concentrations in the surface sediments of the entire lake were 96.2-175.2, 38.3-127.6, 0.2-2.3, 22.5-77.4, and 72.3-254.4mg/kg, respectively. A self-organizing map (SOM) was applied to find the inner element relation of heavy metals in the sediment cores. K-means clustering of the self-organizing map was also completed to define the Euclidian distance of heavy metals in the sediment cores. The geoaccumulation index (I geo ) for Poyang Lake indicated a varying degree of heavy metal contamination in the surface sediment, especially for Cu. The heavy metal contamination in the sediment profiles had similar pollution levels as those of surface sediment, except for Cd. Correlation matrix mapping and principal component analysis (PCA) were used to support the idea that Cr, Pb, and Zn may be mainly derived from both lithogenic and human activities, such as atmospheric and river inflow transportation, whereas Cu and Cd may be mainly contributed from anthropogenic sources, such as mining activities and fertilizer application. Copyright © 2017 Elsevier B.V. All rights reserved.

Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China

PubMed Central

Hu, Rong; Yan, Yun; Zhou, Xiaoli; Wang, Yanan; Fang, Yanming

2018-01-01

Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr), copper (Cu), lead (Pb), vanadium (V), and zinc (Zn)) at five sampling sites (four roads and a forest park) during the summer and winter of 2012. According to the relative accumulation factor (RAF) and contamination factor (CF) results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation (p < 0.05) between traffic volume and concentration for three heavy metals (Cr, Cu, and V) in winter, whereas a significant positive correlation (p < 0.05) was observed between traffic volume and concentrations for four heavy metal elements (Cr, Pb, V, and Zn) in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution. PMID:29470433

Analyses of Mineral Content and Heavy Metal of Honey Samples from South and East Region of Turkey by Using ICP-MS.

PubMed

Kılıç Altun, Serap; Dinç, Hikmet; Paksoy, Nilgün; Temamoğulları, Füsun Karaçal; Savrunlu, Mehmet

2017-01-01

The substantial of mineral ingredients in honey may symbolize the existence of elements in the plants and soil of the vicinity wherein the honey was taken. The aim of this study was to detect the levels of 13 elements (Potassium (K), Sodium (Na), Calcium (Ca), Iron (Fe), Zinc (Zn), Cadmium (Cd), Copper (Cu), Manganese (Mn), Lead (Pb), Nickel (Ni), Chromium (Cr), Aluminum (Al), and Selenium (Se)) in unifloral and multifloral honey samples from south and east regions of Turkey. Survey of 71 honey samples from seven different herbal origins, picked up from the south and east region of Turkey, was carried out to determine their mineral contents during 2015-2016. The mineral contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The most abundant minerals were K, Na, and Ca ranging within 1.18-268 ppm, 0.57-13.1 ppm, and 0.77-4.5 ppm, respectively. Zn and Cu were the most abundant trace element while Pb, Cd, Ni, and Cr were the lowest heavy metals in the honey samples surveyed, with regard to the concentrations of heavy metals such as Zn, Cu, Pb, Cd, Ni, and Cr suggested and influence of the botanical origin of element composition. Geochemical and geographical differences are probably related to the variations of the chemical components of honey samples.

Bioaccumulation and distribution of heavy metals in Maize, Oat and Sorghum Plants, grown in industrially polluted region

NASA Astrophysics Data System (ADS)

Angelova, Violina; Ivanova, Radka; Ivanov, Krasimir

2010-05-01

The uptake of heavy metals (Cd, Pb and Zn) by maize, oat and sorghum plants cultivated, under field conditions, in industrially polluted soils was studied. The experimental plots were situated at different distances (0.1, 2.0 and 15.0 km) from the source of pollution - the Non-Ferrous Metal Works near Plovdiv, Bulgaria. On reaching commercial ripeness the crops were gathered and the contents of heavy metals in their different parts - roots, stems, leaves and grains, were determined after dry ashing. The quantitative measurements were carried out with ICP. A clearly distinguished species peculiarity existed in the accumulation of heavy metals in the vegetative and reproductive organs of the studied crops. Sorghum plants accumulated larger heavy metal quantities compared to maize and oat plants, as the major part of heavy metals was retained by roots and a very small part was translocated to epigeous parts. The studied crops may be considered as metal-tolerant crops and may be cultivated on soils which are low, medium or highly contaminated with lead, zinc and cadmium, as they do not show a tendency of accumulating these elements in epigeous parts and grains above the maximum permissible concentrations. The possible use of aboveground mass and grains for animal food guarantees the economic expedience upon the selection of these crops. Acknowledgment: This work is supported by the Bulgarian Ministry of Education, Project DO-02-87/08.

Mobilization of arsenic and heavy metals from polluted soils by humic acid

NASA Astrophysics Data System (ADS)

Reyes, Arturo; Fuentes, Bárbara; Letelier, María Victoria; Cuevas, Jacqueline

2017-04-01

The existence of soils contaminated with harmful elements by mining activities is a global environmental concern. The northern part of Chile has several heavy metal contaminated sites due to former copper and gold artisanal mining activities. Therefore, a complete characterization of abandoned sites and the implementation of remediation technologies are of interest for regulators, the industry, and the population. The objective of the study was to test the use of humic acid as a washing treatment to reduce the heavy metal concentration of soil samples impacted by mine waste material. A stratified random sampling was conducted on the target site to determine the physical and chemical composition of mine waste and soil material. The sampling consisted of taking 37 samples at 0-20 cm depths in a 10,000 square-meter area. The samples were dried and sieved at 2 mm. The batch washing experiments were conducted in triplicate at pH 7.0. A 1:10 solid to liquid ratio and three humic acid dose (0, 50, and 100 mg/l) were used. After shaking (24 h, room temperature) and subsequently filtration (0.22 μm), the supernatants were analyzed for heavy metals, redox potential and pH. The heavy metals mobility was assessed using extraction methods before and after treatments. The soils had alkaline pH values, conductivity ranged between 8 and 35 mS/cm, with low organic matter. Total concentrations of Vanadium (V) (10.80 to 175.00 mg/kg), Lead (Pb) (7.31 to 90.10 mg/kg), Antimonium (Sb) (0.83 to 101.00 mg/kg), and Arsenic (As) (9.53 to 2691.00 mg/kg) exceeded several times the EPA`s recommended values for soils. At 100 mg/L HA the removal efficiencies for V, Pb, Sb, and As were 32, 68, 77, and 82% respectively. According to the extraction procedure V, Pb, Sb, and As species are mainly as oxidizable and residual fractions. According to the results, the target mine site is contaminated with harmful elements. It can be concluded that the use of humic acid is a good alternative as a treatment to minimize the harmful element mobility. More test must be conducted in order to increase the efficiency of heavy metal removal by using humic acid.

Heavy metals in agricultural soils of the European Union with implications for food safety.

PubMed

Tóth, G; Hermann, T; Da Silva, M R; Montanarella, L

2016-03-01

Soil plays a central role in food safety as it determines the possible composition of food and feed at the root of the food chain. However, the quality of soil resources as defined by their potential impact on human health by propagation of harmful elements through the food chain has been poorly studied in Europe due to the lack of data of adequate detail and reliability. The European Union's first harmonized topsoil sampling and coherent analytical procedure produced trace element measurements from approximately 22,000 locations. This unique collection of information enables a reliable overview of the concentration of heavy metals, also referred to as metal(loid)s including As, Cd, Cr, Cu, Hg, Pb, Zn, Sb. Co, and Ni. In this article we propose that in some cases (e.g. Hg and Cd) the high concentrations of soil heavy metal attributed to human activity can be detected at a regional level. While the immense majority of European agricultural land can be considered adequately safe for food production, an estimated 6.24% or 137,000km(2) needs local assessment and eventual remediation action. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

A comprehensive analysis of the content of heavy rare-earth elements and platinum in snow samples to assess the ecological hazard of air pollution in urban areas

NASA Astrophysics Data System (ADS)

Vinokurov, S. F.; Tarasova, N. P.; Trunova, A. N.; Sychkova, V. A.

2017-07-01

Snow samples from the territory of the Setun River Valley Wildlife Sanctuary are analyzed for the content of rare-earth elements, heavy metals, and other hazardous elements by the inductively coupled plasma mass-spectrometry method. The changes in the concentrations of rare-earth elements, Pt, Pd, and indicator ratios of elements in the solid fractions of snow are revealed. A trend toward a decrease in the content of several elements northeastward of the Moscow Ring Road (MRR) is established. The level of seasonal atmospheric contamination of the area under study is assessed, and a possible source is identified.

Abundances in the Very Metal Poor s-Process-rich Star CS 22183-015

NASA Astrophysics Data System (ADS)

Johnson, Jennifer A.; Bolte, Michael

2002-11-01

We report on the abundances for 13 elements in CS 22183-015, the most metal-poor, s-process-rich star yet discovered. We measure [Fe/H]=-3.12 and large overabundances compared to scaled solar values for 11 heavy elements with s-process origin. The low luminosity of the star suggests that it is a CH star, a giant that has accreted s-processed material from an evolved, very metal poor companion. We find a [Pb/Ba] value of 1.1 dex and, more generally, that the ratio of heavy to light s-process elements is larger than seen in the solar system. This result is consistent with theoretical expectations for the s-process in metal-poor stars. [Eu/La] is higher than predicted from the solar system s-process abundance ratios. We argue that the s-process in metal-poor stars is more efficient at producing Eu that in asymptotic giant branch stars of solar metallicity. Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Monitoring heavy metal concentrations in the sediments of the Moskva and Oka River system- Results of the Volga-Rhine-Project

NASA Astrophysics Data System (ADS)

Andresen, Höpke

2010-05-01

In the course of the Volga-Rhine-Project sediment, water and pore water samples were collected on the Volga as well as the Moskva and Oka river systems. The sampling area discussed here is located south east of the city of Moscow. Sediment samples were taken along the Moskva River between Moscow and the city of Kolomna, which is approximately 100 km to the southeast of Moscow and in the Oka River close to the confluence with the Moskva River (Kolomna). The first sampling campaign in this region took place in 1993, followed by further sampling in 1997 and 2007. For evaluation of sediment quality classification systems are often used. The geo-accumulation index proposed by Mueller (1979) is a classification system which consists of seven classes given by the following expression: I = log2×Cn- geo 1.5×Bn Where Cn = measured concentration; Bn = background value (Turekian & Wedepol 1961) of element n and 1.5 = background matrix correction factor. The geo-accumulation index consists of seven grades (0-6) which indicate the enrichment of an element compared to the background value. These grades range from 'not polluted' to 'very strongly polluted'. Another possibility to express sediment contamination is to evaluate the effects on the ecosystem. The lowest effect level (LEL) gives the concentrations of the heavy metals in sediment below which no effect on the majority of the sediment dwelling organisms is expected. The probable effect level (PEL) represents the concentration of heavy metals above which the organisms frequently will show adverse effects. Both of these approaches were used to evaluate the results of the Volga-Rhine-Project. In the last two decades the concentrations of heavy metals in the sediments decreased by up to 60%. In 1993 sediments revealed high concentrations of several heavy metals such as chromium, cadmium, lead, zinc, arsenic, nickel and cobalt, whereas in 2007 only two sediment samples were classified as 'very strongly polluted' regarding lead and cadmium concentrations. Additionally six other sediment samples were found to be 'strongly polluted' with cadmium, zinc and lead, respectively. Using the ecotoxicological approach on the sediments, chromium, cadmium and zinc are above the PEL, whereas the content of lead exceeds the LEL. Thus, these metals may still cause toxic effects on the fresh water system. Although the input of heavy metals into the river systems has clearly decreased during the last 20 years, there are still some locations where high concentrations of heavy metals are found, suggesting point sources. Especially cadmium still shows significantly higher concentrations than the background value in the entire sampling area. There are even two sampling points where the cadmium concentrations reach approximately 100x the background value. To determine the temporal variation of the heavy metal input, sediment cores were taken. Heavy metal concentrations increase with depth in the cores and show a maximum at a depth of about 35-40 cm. Some part of this increase may be a result of early diagenesis as well as a result of reduced heavy metal input. The nature of the decline of the heavy metal concentrations is still in progress. Despite all the improvements achieved in environmental protection in Russia, still some problems have to be addressed. Especially in urban areas like the Moscow region the number and the size of illegal dump sites is increasing dramatically, leading to strong inputs of heavy metals and other pollutants into the river systems, with consequences for the sensitive eco systems.

Use of geostatistics for assessing the concentration of heavy metals in a stretch of the River Apodi-Mossoro (Rio Grande do Norte State, Brazil).

NASA Astrophysics Data System (ADS)

Bezerra, J. M.; Siqueira, G. M.; Montenegro, A. A. A.; Silva, P. C. M.; Batista, R. O.

2012-04-01

The objective of this study was to assess the environmental changes with respect to the concentration of heavy metals in the sediment contained a stretch of the River Apodi-Mossoró (Rio Grande do Norte State, Brazil), considering changes in land use and soil. The sediment samples were collected at 30 points in the bed Apodi- Mossoró River in a section with features urban-rural town of Mossoró. The concentration of heavy metals in the sediment was determined using composite samples of surface sediments from the bottom with a depth of 20 cm, according to the methodology of APHAAWWA-WPCF (1998), where he subsequently held to determine the presence and quantity of metal concentration total by the technique of atomic absorption spectrometry, and analyzed the following heavy metals: aluminum(Al), cádmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). Data were analyzed using statistical and geostatistical. The geostatistical analysiswas performed by the construction of experimental semivariogramas self-assessment and adjustment by using the technique of Jack-kinifing. The elemento Cd was absent in the samples, which reduces the possibility of environmental contamination events. The average concentrations of the elements under study are within the limits proposed by the environmental legislation (National Environmental Council). However, for the elements Fe, Al and Mn no threshold values, because these are associated with the rocky material of geochemical origin. The elemento Fe had the highest range of values than the other, and all elements except for Zn and Cd showed the presence of outliers, suggesting the possibility that these points are listed as points liable to contribution by human activities. It was verified the presence of human influence, because the elements undergo an increase of concentration values from the point 11, which is located downstream of the urban bus consolidated. The experimental semivariogramas of elements Cu and Zn adjusted to the spherical model, while the elemen Fe was adjusted to the exponential model. The concentration of Mn is set to the Gaussian model, while the other elements (Al, Cr, Ni and Pb) showed pure nugget effect. The spatial variability of heavy metals analyzed in the study area has high spatial discontinuity, being influenced by the presence of human action, leading to the existence of trend in the semivariogram of the data of Al, Ni, Pb and Cr. Being derived values range from 350 m for Cu and Mn, Fe and 400 m to 425 m for Zn. It is recommended that future studies adopt a sampling grid with spacing less than 350 mand is expected to get a better response to the behavior of the spatial variability of the elements.

Adsorption of heavy metals by road deposited solids.

PubMed

Gunawardana, Chandima; Goonetilleke, Ashantha; Egodawatta, Prasanna

2013-01-01

The research study discussed in the paper investigated the adsorption/desorption behaviour of heavy metals commonly deposited on urban road surfaces, namely, Zn, Cu, Cr and Pb, for different particle size ranges of solids. The study outcomes, based on field studies and batch experiments, confirmed that road deposited solids particles contain a significantly high amount of vacant charge sites with the potential to adsorb additional heavy metals. Kinetic studies and adsorption experiments indicated that Cr is the most preferred metal element to associate with solids due to the relatively high electronegativity and high charge density of trivalent cation (Cr(3+)). However, the relatively low availability of Cr in the urban road environment could influence this behaviour. Comparing total adsorbed metals present in solids particles, it was found that Zn has the highest capacity for adsorption to solids. Desorption experiments confirmed that a low concentration of Cu, Cr and Pb in solids was present in water-soluble and exchangeable form, whilst a significant fraction of adsorbed Zn has a high likelihood of being released back into solution. Among heavy metals, Zn is considered to be the most commonly available metal among road surface pollutants.

The effect of heavy metal concentration and soil pH on the abundance of selected microbial groups within ArcelorMittal Poland steelworks in Cracow.

PubMed

Lenart, Anna; Wolny-Koładka, Katarzyna

2013-01-01

The present study aimed to identify the effect of heavy metal concentration and soil pH on the abundance of the selected soil microorganisms within ArcelorMittal Poland steelworks, Cracow. The analysis included 20 soil samples, where the concentration of Fe, Zn, Cd, Pb, Ni, Cu, Mn, Cr and soil pH were evaluated together with the number of mesophilic bacteria, fungi, Actinomycetes and Azotobacter spp. In the majority of samples soil pH was alkaline. The limits of heavy metals exceeded in eight samples and in one sample, the concentration of Zn exceeded 31-fold. Chromium was the element which most significantly limited the number of bacteria and Actinomycetes.

Distributions of Heavy Metals and Benzo[ a]pyrene in Oligotrophic Peat Soils and Peat Gleyzems of Northeastern Sakhalin

NASA Astrophysics Data System (ADS)

Lipatov, D. N.; Shcheglov, A. I.; Manakhov, D. V.; Karpukhin, M. M.; Zavgorodnyaya, Yu. A.; Tsvetnova, O. B.

2018-05-01

The contents and profile distributions of Cr, Ni, Cu, Zn, Cd, Hg, Pb, and benzo[a]pyrene in oligotrophic peat soils, oligotrophic peat gley soils (Dystric Fibric Histosols), humus-impregnated peat gleyzems (Dystric Histic Gleysols), and mucky gleyzems (Dystric Gleysols) have been analyzed with consideration for their degree of oligotrophicity and anthropogenic loads. Horizons with the accumulation (O, Tpyr, TT) and removal (Ghi,e) of heavy metals have been revealed. The increase in the content of heavy metals and benzo[ a]pyrene in the upper layer of oligotrophic peat soils under technogenic fallouts in the impact zone of flare and motor transport has been considered. Statistical parameters of the spatial variation of parameters in organic and gley horizons have been calculated. The variation coefficients of pollutant elements (Pb and Zn) in the surface horizons of soils increase to 100-125%. Positive correlations revealed between the content of some heavy metals in litter indicate their bioaccumulation and possible joint input with aerotechnogenic fallouts. No correlations are found between the contents of benzo[ a]pyrene and heavy metals, but a reliable negative correlation with the ash content is noted in the peat horizon.

Source apportionment and health risk assessment of heavy metals in soil for a township in Jiangsu Province, China.

PubMed

Jiang, Yanxue; Chao, Sihong; Liu, Jianwei; Yang, Yue; Chen, Yanjiao; Zhang, Aichen; Cao, Hongbin

2017-02-01

Human activities contribute greatly to heavy metal pollution in soils. Concentrations of 15 metal elements were detected in 105 soil samples collected from a typical rural-industrial town in southern Jiangsu, China. Among them, 7 heavy metals-lead, copper, zinc, arsenic, chromium, cadmium, and nickel-were considered in the health risk assessment for residents via soil inhalation, dermal contact, and/or direct/indirect ingestion. Their potential sources were quantitatively apportioned by positive matrix factorization using the data set of all metal elements, in combination with geostatistical analysis, land use investigation, and industrial composition analysis. Furthermore, the health risks imposed by sources of heavy metal in soil were estimated for the first time. The results indicated that Cr, Cu, Cd, Pb, Ni, and Co accumulated in the soil, attaining a mild pollution level. The total hazard index values were 3.62 and 6.11, and the total cancer risks were 9.78 × 10 -4 and 4.03 × 10 -4 for adults and children, respectively. That is, both non-carcinogenic and carcinogenic risks posed by soil metals were above acceptable levels. Cr and As require special attention because the health risks of Cr and As individually exceeded the acceptable levels. The ingestion of homegrown produce was predominantly responsible for the high risks. The potential sources were apportioned as: a) waste incineration and textile/dyeing industries (28.3%), b) natural sources (45.4%), c) traffic emissions (5.3%), and d) electroplating industries and livestock/poultry breeding (21.0%). Health risks of four sources accounted for 23.5%, 32.7%, 7.4%, and 36.4% of the total risk, respectively. Copyright © 2016. Published by Elsevier Ltd.

Heavy ligand atom induced large magnetic anisotropy in Mn(ii) complexes.

PubMed

Chowdhury, Sabyasachi Roy; Mishra, Sabyashachi

2017-06-28

In the search for single molecule magnets, metal ions are considered pivotal towards achieving large magnetic anisotropy barriers. In this context, the influence of ligands with heavy elements, showing large spin-orbit coupling, on magnetic anisotropy barriers was investigated using a series of Mn(ii)-based complexes, in which the metal ion did not have any orbital contribution. The mixing of metal and ligand orbitals was achieved by explicitly correlating the metal and ligand valence electrons with CASSCF calculations. The CASSCF wave functions were further used for evaluating spin-orbit coupling and zero-field splitting parameters for these complexes. For Mn(ii) complexes with heavy ligand atoms, such as Br and I, several interesting inter-state mixings occur via the spin-orbit operator, which results in large magnetic anisotropy in these Mn(ii) complexes.

Heavy metal extractable forms in sludge from wastewater treatment plants.

PubMed

Alvarez, E Alonso; Mochón, M Callejón; Jiménez Sánchez, J C; Ternero Rodríguez, M

2002-05-01

The analysis of heavy metals is a very important task to assess the potential environmental and health risk associated with the sludge coming from wastewater treatment plants (WWTPs). However, it is widely accepted that the determination of total elements does not give an accurate estimation of the potential environmental impact. So, it is necessary to apply sequential extraction techniques to obtain a suitable information about their bioavailability or toxicity. In this paper, a sequential extraction scheme according to the BCR's guidelines was applied to sludge samples collected from each sludge treatment step of five municipal activated sludge plants. Al. Cd, Co, Cu, Cr, Fe, Mn, Hg, Mo, Ni, Pb, Ti and Zn were determined in the sludge extracts by inductively coupled plasma atomic emission spectrometry. In relation to current international legislation for the use of sludge for agricultural purposes none of metal concentrations exceeded maximum permitted levels. In most of the metal elements under considerations, results showed a clear rise along the sludge treatment in the proportion of two less-available fractions (oxidizable metal and residual metal).

Endophytic bacteria and their potential to enhance heavy metal phytoextraction.

PubMed

Rajkumar, Mani; Ae, Noriharu; Freitas, Helena

2009-09-01

Pollution of soils with heavy metals is becoming one of the most severe environmental and human health hazards. Due to its widespread contamination finding innovative ways to clean metal pollutant has become a priority in the remediation field. Phytoremediation, the use of plants for the restoration of environments contaminated with pollutants is a relatively new technology that is more benign than current engineering solutions to treat contaminated sites. Recently, the benefits of combining endophytic bacteria with plants for increased remediation of pollutants have been successfully tried for toxic metal removal from contaminated soils. Endophytic bacteria reside within plant hosts without causing disease symptoms. Further, the metal resistant endophytes are reported to be present in various hyperaccumulator plants growing on heavy metal contaminated soils and play an important role in successful survival and growth of plants. Moreover, the metal resistant endophytes are reported to promote plant growth by various mechanisms such as nitrogen fixation, solubilization of minerals, production of phytohormones, siderophores, utilization of 1-aminocyclopropane-1-carboxylic acid as a sole N source and transformation of nutrient elements. In this review we highlight the diversity and plant growth promoting features of metal resistant endophytic bacteria and discuss their potential in phytoextraction of heavy metals from contaminated soils.

Association of urinary metal profiles with altered glucose levels and diabetes risk: a population-based study in China.

PubMed

Feng, Wei; Cui, Xiuqing; Liu, Bing; Liu, Chuanyao; Xiao, Yang; Lu, Wei; Guo, Huan; He, Meian; Zhang, Xiaomin; Yuan, Jing; Chen, Weihong; Wu, Tangchun

2015-01-01

Elevated heavy metals and fasting plasma glucose (FPG) levels were both associated with increased risk of cardiovascular diseases. However, studies on the associations of heavy metals and essential elements with altered FPG and diabetes risk were limited or conflicting. The objective of this study was to evaluate the potential associations of heavy metals and essential trace elements with FPG and diabetes risk among general Chinese population. We conducted a cross-sectional study to investigate the associations of urinary concentrations of 23 metals with FPG, impaired fasting glucose (IFG) and diabetes among 2242 community-based Chinese adults in Wuhan. We used the false discovery rate (FDR) method to correct for multiple hypothesis tests. After adjusting for potential confounders, urinary aluminum, titanium, cobalt, nickel, copper, zinc, selenium, rubidium, strontium, molybdenum, cadmium, antimony, barium, tungsten and lead were associated with altered FPG, IFG or diabetes risk (all P< 0.05); arsenic was only dose-dependently related to diabetes (P< 0.05). After additional adjustment for multiple testing, titanium, copper, zinc, selenium, rubidium, tungsten and lead were still significantly associated with one or more outcomes (all FDR-adjusted P< 0.05). Our results suggest that multiple metals in urine are associated with FPG, IFG or diabetes risk. Because the cross-sectional design precludes inferences about causality, further prospective studies are warranted to validate our findings.

Effects of urban air pollutants on elemental accumulation and identification of oxidative stress biomarkers in the transplanted lichen Pseudovernia furfuracea.

PubMed

Oztetik, Elif; Cicek, Arzu

2011-07-01

Determining the origins of heavy metals, their accumulation, and their detoxification mechanisms constitutes a major problem in understanding environmental pollution in urban areas. The objective of this study was to detect the relative air quality in Eskisehir city center (Turkey) through the transplanted epiphytic lichen Pseudovernia furfuracea as a biomonitor of the concentrations of some heavy metals accumulated and to describe their toxic effects on lichen physiology during the study period of one year. The influence of heavy metal accumulations on macroelement levels were also examined. In addition to analysis of B, K, Ca, P, S, Al, Fe, Mg, Mn, Ni, Zn, Pb, and Cu, total soluble proteins and oxidative stress parameters through glutathione (GSH) contents and glutathione S-transferase (GST) activities were also determined. Results indicate that, although the heavy metal concentrations were found to be gradually increased from the unpolluted control zone to the city center, the concentrations of macroelements S and Ca were higher in the polluted area. However, B, K, Mg, and P elements were found to be higher in the unpolluted area than in the polluted zones. It seems that heavy metals induce oxidative stress in lichens; we found enhancement of GSH concentrations and GST activity. Most probably, the expected destruction in this organism was reduced by the intervention of antioxidant capacity. Therefore, this report confirms the fact that the epiphytic lichen P. furfuracea is a good model for biomonitoring atmospheric quality for a long-term transplantation study, and oxidative stress parameters stand out as a tool for an early environment assessment of other physiological parameters. Copyright © 2011 SETAC.

Effects of Application of NTA and EDTA on Accumulation of Soil Heavy Metals in Chrysanthemum

NASA Astrophysics Data System (ADS)

Bai, Weiyang

2018-02-01

In order to find out the effect of non-bio chelating agent EDTA and bio-chelating agent NTA on soil heavy metal pollution, the effects of different ratio of chelating agent NTA and EDTA on soil heavy metals (Pb, Cu and Cd ), the effects of chelating on content of chlorophyll and vitamin C and the degree of soil nutrient loss were evaluated. The results showed: that the contents of Pb and Cd were the highest in the roots of Chrysanthemum in the treatment (EDTA / NTA = 2: 1). The treatment (EDTA / NTA = 1: 1) was the best chelating agent ratio for the synergistic effect, which can significantly promoted the Chrysanthemum on heavy metal Cu uptake and transport to aboveground. Chrysanthemum were inhibited by all chelating agents treatments, while the content of chlorophyll and vitamin C of the Chrysanthemum physiological indexes were reduced. In the treatment (EDTA = 1), chlorophyll SPAD, vitamin C content reached a minimum of 36 and 38mg · 100g-1, respectively. The nutrient element TN in the leachate were gradually decreased with the time, and the tenth day was significantly lower than the leaching rate of the first day (p <0.05) in the treatments (NTA = 1, EDTA / NTA = 1: 2). The nutrient element TN was decreased most, reaching 51.6%, and the activation effect was decreased significantly in the fifteenth day in treatment (NTA = 1), Treatment(EDTA / NTA = 1: 1)> treatment (EDTA = 1) >treatment (EDTA / NTA = 2: 1) >treatment (EDTA / NTA = 1: 2)> treatment (NTA = 1). Treatment (EDTA / NTA = 2: 1) was recommended for the chelating agent ratio with the better physiological parameters, the more heavy metal extraction and the less nitrogen and phosphorus loss

Evaluation of heavy metals and polycyclic aromatic hydrocarbons in honeys from different origins.

PubMed

Corredera, Lourdes; Bayarri, Susana; Pérez-Arquillué, Consuelo; Lázaro, Regina; Molino, Francisco; Herrera, Antonio

2014-03-01

A survey of honey samples from different geographical and botanical origins, including some samples collected from a fire-affected area in Spain, was conducted to assess their content of heavy metals and polycyclic aromatic hydrocarbons (PAHs). The levels of the determined toxic elements (Pb, Cd, As, and Sn) were low and were in the range of those reported by other studies. In our work the total amount of heavy metals and Pb was higher in dark honeys than in pale honeys. In the collected samples, no detectable levels of the 15 PAHs studied were found. The obtained data served to assess the levels of heavy metals and PAHs in honey samples from different geographical and environmental origins and to contribute to the scarce data about pollutant content of this matrix. In light of these results, the analyzed samples do not pose any serious concern to human health, and the data obtained in this study could serve to contribute to the establishment of specific maximum limits for honey.

Quantitative relations between soil heavy metal contamination and landscape pattern in Wuxi, China

NASA Astrophysics Data System (ADS)

Zhu, Ming; Pu, Lijie; Xu, Yan

2017-04-01

Land use practices changed landscape pattern and meanwhile, brought forth numerous environmental problems including heavy metal contamination in soil. In this study, we investigated the quantitative relations between soil heavy metal contamination and its surrounding landscape pattern based on topsoil samples and land use map of Wuxi in 2009. The results of vector fitting with Redundancy analysis in R package vegan showed that Percent Coverage of build-up area (PCB) within 2500 m, Perimeter-Area Fractal Dimension (PAFD) within 2500 m, Edge Density (ED) within 2500 m, Patch Density (PD) within 200 m, Percent Coverage of wetland (PCW) within 2000 m and Patch Cohesion (PC) within 200 m significantly affected the contents of heavy metal elements. The results of Stepwise regression suggested that increase of build-up area and fragmentation would increase Cu and Zn, while increase of wetland would decrease the contents of As and Cu. PAFD was negative with Cd, Hg, Pb and Zn.

Heavy element affinities in Apollo 17 samples

NASA Technical Reports Server (NTRS)

Allen, R. O., Jr.; Jovanovic, S.; Reed, G. W., Jr.

1975-01-01

Pb-204, Bi, Tl, and Zn in samples from the Apollo 17 site exhibit relationships not found in samples from other sites. Pb-204, Tl, and Zn in residues remaining after dilute acid leaching are correlated with one another. Orange soil 74220, which is enriched in Pb-204, Tl, and Zn, is included in these relationships. In addition, the submicron metallic phase generally associated with agglutinate formation is correlated with all three of these elements; this relationship has already been reported for Pb-204 in other samples. Thus, orange soil and agglutinates appear to be involved in concentrating heavy volatile metals. A process other than mixing is required to account for this. As a consequence of the isolation of the landing site by the surrounding massifs, local supply and recycling of volatile trace elements in soils may account for some of the interelement relations.

Identification of an exposure risk to heavy metals from pharmaceutical-grade rubber stoppers.

PubMed

Li, Xianghui; Qian, Pingping

2017-07-01

Exposure to low concentrations of heavy metals and metalloids represents a well-documented risk to animal and human health. However, current standards (European Pharmacopeia [EP], United States Pharmacopoeia [USP], International Organization for Standardization [ISO], YBB concerned with rubber closures) only require testing for Zn in pharmaceutical-grade rubber stoppers and then using only pure water as a solvent. We extracted and quantified heavy metals and trace elements from pharmaceutical-grade rubber stoppers under conditions that might occur during the preparation of drugs. Pure water, saline, 10% glucose, 3% acetic acid (w/v), 0.1 mol/L hydrochloric acid, and diethylenetriaminepentaacetic acid (4 mg/mL, 0.4 mg/mL, and 0.04 mg/mL) were used as extraction agents. We quantified the extracted arsenic, lead, antimony, iron, magnesium, aluminum, and zinc using inductively coupled plasma mass spectrometry. The concentration of extracted metals varied depending on the different extraction solutions used and between the different rubber stopper manufacturers. Rubber stoppers are ubiquitously used in the pharmaceutical industry for the storage and preparation of drugs. Extraction of heavy metals during the manufacturing and preparation of drugs represents a significant risk, suggesting a need for industry standards to focus on heavy metal migration from rubber stoppers. Copyright © 2016. Published by Elsevier B.V.

The effect of sampling scheme in the survey of atmospheric deposition of heavy metals in Albania by using moss biomonitoring.

PubMed

Qarri, Flora; Lazo, Pranvera; Bekteshi, Lirim; Stafilov, Trajce; Frontasyeva, Marina; Harmens, Harry

2015-02-01

The atmospheric deposition of heavy metals in Albania was investigated by using a carpet-forming moss species (Hypnum cupressiforme) as bioindicator. Sampling was done in the dry seasons of autumn 2010 and summer 2011. Two different sampling schemes are discussed in this paper: a random sampling scheme with 62 sampling sites distributed over the whole territory of Albania and systematic sampling scheme with 44 sampling sites distributed over the same territory. Unwashed, dried samples were totally digested by using microwave digestion, and the concentrations of metal elements were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and AAS (Cd and As). Twelve elements, such as conservative and trace elements (Al and Fe and As, Cd, Cr, Cu, Ni, Mn, Pb, V, Zn, and Li), were measured in moss samples. Li as typical lithogenic element is also included. The results reflect local emission points. The median concentrations and statistical parameters of elements were discussed by comparing two sampling schemes. The results of both sampling schemes are compared with the results of other European countries. Different levels of the contamination valuated by the respective contamination factor (CF) of each element are obtained for both sampling schemes, while the local emitters identified like iron-chromium metallurgy and cement industry, oil refinery, mining industry, and transport have been the same for both sampling schemes. In addition, the natural sources, from the accumulation of these metals in mosses caused by metal-enriched soil, associated with wind blowing soils were pointed as another possibility of local emitting factors.

Heavy metals accumulation affects bone microarchitecture in osteoporotic patients.

PubMed

Scimeca, Manuel; Feola, Maurizio; Romano, Lorenzo; Rao, Cecilia; Gasbarra, Elena; Bonanno, Elena; Brandi, Maria Luisa; Tarantino, Umberto

2017-04-01

Bone metabolism is affected by mechanical, genetic, and environmental factors and plays a major role in osteoporosis. Nevertheless, the influence of environmental pollution on the occurrence of osteoporosis is still unclear and controversial. In this context, heavy metals are the most important pollutants capable to affect bone mass. The aim of this study was to investigate whether heavy metals accumulation in bone tissues could be related to the altered bone metabolism and architecture of osteoporotic patients. To this end, we analyzed 25 bone head biopsies osteoporotic patients and 25 bone head biopsies of osteoarthritic patients. Moreover we enrolled 15 patients underwent hip arthroplasty for high-energy hip fracture or osteonecrosis of the femoral head as a control group. Bone head biopsies were studied by BioQuant-osteo software, scanning electron microscopy and Energy Dispersive X-ray microanalysis. We found a prevalence of lead, cadmium and chromium accumulation in osteoporotic patients. Noteworthy, high levels of sclerostin, detected by immunohistochemistry, correlate with the accumulation of heavy metal found in the bone of osteoporotic patients, suggesting a molecular link between heavy metal accumulation and bone metabolism impairment. In conclusion, the presence of heavy metals into bone shed new light on the comprehension of the pathogenesis of osteoporosis since these elements could play a non redundant role in the development of osteoporosis at cellular/molecular and epigenetic level. Nevertheless, in vivo and in vitro studies need to better elucidate the molecular mechanism in which heavy metals can participate to osteoporosis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1333-1342, 2017. © 2016 Wiley Periodicals, Inc.

[Pollution evaluation and health risk assessment of heavy metals from atmospheric deposition in Lanzhou].

PubMed

Li, Ping; Xue, Su-Yin; Wang, Sheng-Li; Nan, Zhong-Ren

2014-03-01

In order to evaluate the contamination and health risk of heavy metals from atmospheric deposition in Lanzhou, samples of atmospheric deposition were collected from 11 sampling sites respectively and their concentrations of heavy metals were determined. The results showed that the average contents of Cu, Pb, Cd, Cr, Ni, Zn and Mn were 82.22, 130.31, 4.34, 88.73, 40.64, 369.23 and 501.49 mg x kg(-1), respectively. There was great difference among different functional areas for all elements except Mn. According to the results, the enrichment factor score of Mn was close to 1, while the enrichment of Zn, Ni, Cu and Cr was more serious, and Pb and Cd were extremely enriched. The assessment results of geoaccumulation index of potential ecological risk indicated that the pollution of Cd in the atmospheric deposition of Lanzhou should be classified as extreme degree, and that of Cu, Ni, Zn, Pb as between slight and extreme degrees, and Cr as practically uncontaminated. Contaminations of atmospheric dust by heavy metals in October to the next March were more serious than those from April to August. Health risk assessment indicated that the heavy metals in atmospheric deposition were mainly ingested by human bodies through hand-mouth ingestion. The non-cancer risk was higher for children than for adults. The order of non-cancer hazard indexes of heavy metals was Pb > Cr > Cd > Cu > Ni > Zn. The non-cancer hazard indexes and carcinogen risks of heavy metals were both lower than their threshold values, suggesting that they will not harm the health.

Sources, spatial variation, and speciation of heavy metals in sediments of the Tamagawa River in Central Japan.

PubMed

Shikazono, N; Tatewaki, K; Mohiuddin, K M; Nakano, T; Zakir, H M

2012-01-01

Sediments of the Tamagawa River in central Japan were studied to explain the spatial variation, to identify the sources of heavy metals, and to evaluate the anthropogenic influence on these pollutants in the river. Sediment samples were collected from 20 sites along the river (five upstream, four midstream, and 11 downstream). Heavy metal concentrations, viz. chromium, nickel, copper, zinc, lead, cadmium, and molybdenum, in the samples were measured using inductively coupled plasma-mass spectroscopy. The chemical speciations of heavy metals in the sediments were identified by the widely used five-step Hall method. Lead isotopes were analyzed to identify what portion is contributed by anthropogenic sources. The total heavy metal concentrations were compared with global averages for continental crust (shale) and average values for Japanese river sediments. The mean heavy metal concentrations were higher in downstream sediments than in upstream and midstream samples, and the concentrations in the silt samples were higher than those in the sand samples. Speciation results demonstrate that, for chromium and nickel, the residual fractions were dominant. These findings imply that the influence of anthropogenic chromium and nickel contamination is negligible, while copper, zinc, and lead were mostly extracted in the non-residual fraction (metals in adsorbed/exchangeable/carbonate forms or bound to amorphous Fe oxyhydroxides, crystalline Fe oxides, or organic matter), indicating that these elements have high chemical mobility. The proportion of lead (Pb) isotopes in the downstream silt samples indicates that Pb accumulation is primarily derived from anthropogenic sources.

Antimicrobial resistance and its association with tolerance to heavy metals in agriculture production.

PubMed

Yu, Zhongyi; Gunn, Lynda; Wall, Patrick; Fanning, Séamus

2017-06-01

Antimicrobial resistance is a recognized public health challenge that since its emergence limits the therapeutic options available to veterinarians and clinicians alike, when treatment is warranted. This development is further compounded by the paucity of new antibiotics. The agri-food industry benefits from the availability of antimicrobial compounds for food-animal production and crop protection. Nonetheless, their improper use can result in the selection for bacteria that are phenotypically resistant to these compounds. Another class of agents used in agriculture includes various cationic metals that can be included in animal diets as nutritional supplements or spread on pastures to support crop growth and protection. Heavy metals, in particular, are giving rise to concerns among public health professionals, as they can persist in the environment remaining stable for prolonged periods. Moreover, bacteria can also exhibit resistance to these chemical elements and the genes encoding this phenotype can be physically localized to plasmids that may also contain one or more antimicrobial resistance-encoding gene(s). This paper reviews our current understanding of the role that bacteria play in expressing resistance to heavy metals. It will describe how heavy metals are used in agri-food production, and explore evidence available to link resistance to heavy metals and antimicrobial compounds. In addition, possible solutions to reduce the impact of heavy metal resistance are also discussed, including using organic minerals and reducing the level of trace minerals in animal feed rations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Migration of copper and some other metals from copper tableware

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

Ishiwata, H.; Inoue, T.; Yoshihira, K.

Intake of heavy metals is an important problem in human health. Certain heavy metals are avoided with regard to their use for utensils or tableware coming into contact with food, although copper is widely used in food processing factories or at home. The use of copper products for the processing, cooking or serving of foods and beverages is considered to be a cause of a copper contamination. Although copper is essential element, its excess ingestion is undesirable. In this study, the migration of copper from tin-plated or non-plated copperware under several experimental conditions was investigated using food-simulating solvents.

Study of heavy metals and other elements in macrophyte algae using energy-dispersive X-ray fluorescence

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

Carvalho, M.L.; Amorim, P.; Marques, M.I.M.

1997-04-01

Fucus vesiculosus L. seaweeds from three estuarine stations were analyzed by X-ray fluorescence, providing results for the concentration of total K, Ca, Ti, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Sr, and Pb. Four different structures of the algae (base, stipe, reproductive organs, and growing tips) were analyzed to study the differential accumulation of heavy metals by different parts of Fucus. Some elements (e.g., Cu and Fe) are preferentially accumulated in the base of the algae, whereas others (e.g., As) exhibit higher concentrations in the reproductive organs and growing tips. The pattern of accumulation in different structures is similarmore » for Cu, Zn, and Pb, but for other metals there is considerable variability in accumulation between parts of the plant. This is important in determining which structures of the plant should be used for biomonitoring. For samples collected at stations subject to differing metal loads, the relative elemental composition is approximately constant, notwithstanding significant variation in absolute values. The proportion of metals in Fucus is similar to that found in other estuaries, where metal concentrations are significantly lower. Energy-dispersive X-ray fluorescence has been shown to be a suitable technique for multielement analysis in this type of sample. No chemical pretreatment is required, minimizing sample contamination. The small amount of sample required, and the wide range of elements that can be detected simultaneously make energy-dispersive X-ray fluorescence a valuable tool for pollution studies.« less

Multiscale analysis of the spatial variability of heavy metals and organic matter in soils and groundwater across Spain

NASA Astrophysics Data System (ADS)

Luque-Espinar, J. A.; Pardo-Igúzquiza, E.; Grima-Olmedo, J.; Grima-Olmedo, C.

2018-06-01

During the last years there has been an increasing interest in assessing health risks caused by exposure to contaminants found in soil, air, and water, like heavy metals or emerging contaminants. This work presents a study on the spatial patterns and interaction effects among relevant heavy metals (Sb, As and Pb) that may occur together in different minerals. Total organic carbon (TOC) have been analyzed too because it is an essential component in the regulatory mechanisms that control the amount of metal in soils. Even more, exposure to these elements is associated with a number of diseases and environmental problems. These metals can have both natural and anthropogenic origins. A key component of any exposure study is a reliable model of the spatial distribution the elements studied. A geostatistical analysis have been performed in order to show that selected metals are auto-correlated and cross-correlated and type and magnitude of such cross-correlation varies depending on the spatial scale under consideration. After identifying general trends, we analyzed the residues left after subtracting the trend from the raw variables. Three scales of variability were identified (compounds or factors) with scales of 5, 35 and 135 km. The first factor (F1) basically identifies anomalies of natural origin but, in some places, of anthropogenics origin as well. The other two are related to geology (F2 and F3) although F3 represents more clearly geochemical background related to large lithological groups. Likewise, mapping of two major structures indicates that significant faults have influence on the distribution of the studied elements. Finally, influence of soil and lithology on groundwater by means of contingency analysis was assessed.

Concentrations of potentially toxic elements in soils and vegetables from the macroregion of São Paulo, Brazil: availability for plant uptake.

PubMed

dos Santos-Araujo, Sabrina Novaes; Alleoni, Luís Reynaldo Ferracciú

2016-02-01

The occurrence and accumulation of heavy metals or so-called potentially toxic elements (PTEs) in soils and plants have driven long-standing concerns about the adverse effects such metals have on the environment and human health. Furthermore, contaminated food products are known to be a leading source of exposure to heavy metals for the general population. It is crucial to accurately assess the concentrations of metals in crops and the bioavailable contents of these elements in the soil. The state of São Paulo is the largest consumer market of horticultural products in Brazil with production focused essentially on urban and industrial areas, which greatly increases the degree of exposure to contaminants. The objective of the authors in this study was to evaluate the soil-plant relationships between concentrations of Cd, Cu, Ni, Pb and Zn in vegetable and garden soils in the state of São Paulo, Brazil. To accomplish this, 200 soil (0-20 cm) and plant samples were collected from 25 species in the production areas. With the exception of Cd, there was positive correlation between pseudototals (USEPA 3051a) and bioavailable contents (extracted with DTPA) of heavy metals. However, the Cd and Pb contents in plants were not significantly correlated with any of the variables studied. All random forest and tree models proved to be good predictors of results generated from a regression model and provided useful information including covariates that were important for specifically forecasting Zn concentration in plants.

Trace elements in agroecosystems and impacts on the environment.

PubMed

He, Zhenli L; Yang, Xiaoe E; Stoffella, Peter J

2005-01-01

Trace elements mean elements present at low concentrations (mg kg-1 or less) in agroecosystems. Some trace elements, including copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), molybdenum (Mo), and boron (B) are essential to plant growth and are called micronutrients. Except for B, these elements are also heavy metals, and are toxic to plants at high concentrations. Some trace elements, such as cobalt (Co) and selenium (Se), are not essential to plant growth but are required by animals and human beings. Other trace elements such as cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), mercury (Hg), and arsenic (As) have toxic effects on living organisms and are often considered as contaminants. Trace elements in an agroecosystem are either inherited from soil parent materials or inputs through human activities. Soil contamination with heavy metals and toxic elements due to parent materials or point sources often occurs in a limited area and is easy to identify. Repeated use of metal-enriched chemicals, fertilizers, and organic amendments such as sewage sludge as well as wastewater may cause contamination at a large scale. A good example is the increased concentration of Cu and Zn in soils under long-term production of citrus and other fruit crops. Many chemical processes are involved in the transformation of trace elements in soils, but precipitation-dissolution, adsorption-desorption, and complexation are the most important processes controlling bioavailability and mobility of trace elements in soils. Both deficiency and toxicity of trace elements occur in agroecosystems. Application of trace elements in fertilizers is effective in correcting micronutrient deficiencies for crop production, whereas remediation of soils contaminated with metals is still costly and difficult although phytoremediation appears promising as a cost-effective approach. Soil microorganisms are the first living organisms subjected to the impacts of metal contamination. Being responsive and sensitive, changes in microbial biomass, activity, and community structure as a result of increased metal concentration in soil may be used as indicators of soil contamination or soil environmental quality. Future research needs to focus on the balance of trace elements in an agroecosystem, elaboration of soil chemical and biochemical parameters that can be used to diagnose soil contamination with or deficiency in trace elements, and quantification of trace metal transport from an agroecosystem to the environment.

Toxicity, mechanism and health effects of some heavy metals

PubMed Central

Jaishankar, Monisha; Tseten, Tenzin; Anbalagan, Naresh; Beeregowda, Krishnamurthy N.

2014-01-01

Heavy metal toxicity has proven to be a major threat and there are several health risks associated with it. The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning. They sometimes act as a pseudo element of the body while at certain times they may even interfere with metabolic processes. Few metals, such as aluminium, can be removed through elimination activities, while some metals get accumulated in the body and food chain, exhibiting a chronic nature. Various public health measures have been undertaken to control, prevent and treat metal toxicity occurring at various levels, such as occupational exposure, accidents and environmental factors. Metal toxicity depends upon the absorbed dose, the route of exposure and duration of exposure, i.e. acute or chronic. This can lead to various disorders and can also result in excessive damage due to oxidative stress induced by free radical formation. This review gives details about some heavy metals and their toxicity mechanisms, along with their health effects. PMID:26109881

Pollution assessment and source apportionment of heavy metals in contaminated site soils

NASA Astrophysics Data System (ADS)

Zheng, Hongbo; Ma, Yan

2018-03-01

Pollution characteristics of heavy metals in soil were analyzed with a typical contaminated site as the case area. The pollution degree of the element was evaluated by indexes of geoaccumulation (Igeo). The potential ecological risk of heavy metals was assessed with potential ecological risk index model. Principal component analysis (PCA) model was simultaneously carried out to identify the main sources of heavy metals in topsoils. The results indicated that: 1. Mean values of 11 kinds of metals in topsoils were greater than respective soil background values, following the order: Zn>Pb>V>Cr>Cu>Ni>Co>As>Sb>Cd>Hg. Heavy metals with a certain accumulation in the research area were significantly affected by external factors. 2. Igeo results showed that Cd and Zn reached strongly polluted degree, while Pb with moderately to strongly polluted, Sb and Hg with moderately polluted, Cu, Co, Ni and Cr with unpolluted to moderately polluted, V and As with un-polluted. 3. Potential ecological risk assessment showed the degree of ecological risk with Cd at very high risk, Hg at high risk, Pb at moderate risk and others at low risk. The comprehensive risk of all the metals was very high. 4. PCA got three main sources with contributions, including industrial activities (44.18%), traffic and burning dust (26.68%) and soil parent materials (12.20%).

Migration Potential of Contaminants in the Soil of Rocky Mountain Arsenal, I. Open Literature Review.

DTIC Science & Technology

1979-01-01

Organochlorine Insecticides. 14 3. Organophosphorous Insecticides. 17 4. DIMP, DCPD and DBCP. 19 B. Inorganics . 22 1. General. 22 2. Heavy Metals.. 24 3...and DBCP. 2. Inorganics - heavy metals and soluble salts. The specific elements or compounds focused on were those which have been shown to exist in...the initial moisture content of the soil was raised S..21 B. Inorganics . 1. General, The two most common types of inorganic contaminants in soil are

Cosmological quantum chromodynamics, neutron diffusion, and the production of primordial heavy elements

NASA Technical Reports Server (NTRS)

Applegate, J. H.; Hogan, Craig J.; Scherrer, R. J.

1988-01-01

A simple one-dimensional model is used to describe the evolution of neutron density before and during nucleosynthesis in a high-entropy bubble left over from the cosmic quark-hadron phase transition. It is shown why cosmic nucleosynthesis in such a neutron-rich environment produces a surfeit of elements heavier than lithium. Analytical and numerical techniques are used to estimate the abundances of carbon, nitrogen, and heavier elements up to Ne-22. A high-density neutron-rich region produces enough primordial N-14 to be observed in stellar atmospheres. It shown that very heavy elements may be created in a cosmological r-process; the neutron exposure in the neutron-rich regions is large enough for the Ne-22 to trigger a catastrophic r-process runaway in which the quantity of heavy elements doubles in much less than an expansion time due to fission cycling. A primordial abundance of r-process elements is predicted to appear as an excess of rare earth elements in extremely metal-poor stars.

Health risk assessment on human exposed to heavy metals in the ambient air PM10 in Ahvaz, southwest Iran

NASA Astrophysics Data System (ADS)

Goudarzi, Gholamreza; Alavi, Nadali; Geravandi, Sahar; Idani, Esmaeil; Behrooz, Hamid Reza Adeli; Babaei, Ali Akbar; Alamdari, Farzaneh Aslanpour; Dobaradaran, Sina; Farhadi, Majid; Mohammadi, Mohammad Javad

2018-06-01

Heavy metals (HM) are one of the main components of urban air pollution. Today, megacities and industrial regions in southwest of Iran are frequently suffering from severe haze episodes, which essentially caused by PM10-bound heavy metals. The purpose of this study was to evaluate the health risk assessment on human exposed to heavy metals (Cr, Ni, Pb, and Zn) in the ambient air PM10 in Ahvaz, southwest Iran. In this study, we estimated healthy people from the following scenarios: (S3) residential site; (S2) high-traffic site; (S1) industrial site in Ahvaz metropolitan during autumn and winter. In the current study, high-volume air samplers equipped with quartz fiber filters were used to sampling and measurements of heavy metal concentration. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was utilized for detection of heavy metal concentration (ng m-3). Also, an estimate of the amount of health risk assessment (hazard index) of Cr, Ni, Pb, and Zn of heavy metal exposure to participants was used. Result of this study showed that the residential and industrial areas had the lowest and the highest level of heavy metal. Based on the result of this study, average levels of heavy metal in industrial, high-traffic, and residential areas in autumn and winter were 31.48, 30.89, and 23.21 μg m-3 and 42.60, 37.70, and 40.07 μg m-3, respectively. Based on the result of this study, the highest and the lowest concentration of heavy metal had in the industrial and residential areas. Zn and Pb were the most abundant elements among the studied PM10-bound heavy metals, followed by Cr and Ni. The carcinogenic risks of Cr, Pb, and the integral HQ of metals in PM10 for children and adults via inhalation and dermal exposures exceeded 1 × 10-4 in three areas. Also, based on the result of this study, the values of hazard index (HI) of HM exposure in different areas were significantly higher than standard. The health risks attributed to HM should be further investigated from the perspective of the public health in metropolitans. The result of this study showed increasing exposure concentrations to heavy metal in the studied scenarios have a significant potential for generating different health endpoints, while environmental health management in ambient air can cause disorders in citizenship and causing more spiritual and material costs.

Health risk assessment on human exposed to heavy metals in the ambient air PM10 in Ahvaz, southwest Iran.

PubMed

Goudarzi, Gholamreza; Alavi, Nadali; Geravandi, Sahar; Idani, Esmaeil; Behrooz, Hamid Reza Adeli; Babaei, Ali Akbar; Alamdari, Farzaneh Aslanpour; Dobaradaran, Sina; Farhadi, Majid; Mohammadi, Mohammad Javad

2018-06-01

Heavy metals (HM) are one of the main components of urban air pollution. Today, megacities and industrial regions in southwest of Iran are frequently suffering from severe haze episodes, which essentially caused by PM 10 -bound heavy metals. The purpose of this study was to evaluate the health risk assessment on human exposed to heavy metals (Cr, Ni, Pb, and Zn) in the ambient air PM 10 in Ahvaz, southwest Iran. In this study, we estimated healthy people from the following scenarios: (S3) residential site; (S2) high-traffic site; (S1) industrial site in Ahvaz metropolitan during autumn and winter. In the current study, high-volume air samplers equipped with quartz fiber filters were used to sampling and measurements of heavy metal concentration. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was utilized for detection of heavy metal concentration (ng m -3 ). Also, an estimate of the amount of health risk assessment (hazard index) of Cr, Ni, Pb, and Zn of heavy metal exposure to participants was used. Result of this study showed that the residential and industrial areas had the lowest and the highest level of heavy metal. Based on the result of this study, average levels of heavy metal in industrial, high-traffic, and residential areas in autumn and winter were 31.48, 30.89, and 23.21 μg m -3 and 42.60, 37.70, and 40.07 μg m -3 , respectively. Based on the result of this study, the highest and the lowest concentration of heavy metal had in the industrial and residential areas. Zn and Pb were the most abundant elements among the studied PM 10 -bound heavy metals, followed by Cr and Ni. The carcinogenic risks of Cr, Pb, and the integral HQ of metals in PM 10 for children and adults via inhalation and dermal exposures exceeded 1 × 10 -4 in three areas. Also, based on the result of this study, the values of hazard index (HI) of HM exposure in different areas were significantly higher than standard. The health risks attributed to HM should be further investigated from the perspective of the public health in metropolitans. The result of this study showed increasing exposure concentrations to heavy metal in the studied scenarios have a significant potential for generating different health endpoints, while environmental health management in ambient air can cause disorders in citizenship and causing more spiritual and material costs.

Health risk assessment on human exposed to heavy metals in the ambient air PM10 in Ahvaz, southwest Iran

NASA Astrophysics Data System (ADS)

Goudarzi, Gholamreza; Alavi, Nadali; Geravandi, Sahar; Idani, Esmaeil; Behrooz, Hamid Reza Adeli; Babaei, Ali Akbar; Alamdari, Farzaneh Aslanpour; Dobaradaran, Sina; Farhadi, Majid; Mohammadi, Mohammad Javad

2018-02-01

Heavy metals (HM) are one of the main components of urban air pollution. Today, megacities and industrial regions in southwest of Iran are frequently suffering from severe haze episodes, which essentially caused by PM10-bound heavy metals. The purpose of this study was to evaluate the health risk assessment on human exposed to heavy metals (Cr, Ni, Pb, and Zn) in the ambient air PM10 in Ahvaz, southwest Iran. In this study, we estimated healthy people from the following scenarios: (S3) residential site; (S2) high-traffic site; (S1) industrial site in Ahvaz metropolitan during autumn and winter. In the current study, high-volume air samplers equipped with quartz fiber filters were used to sampling and measurements of heavy metal concentration. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was utilized for detection of heavy metal concentration (ng m-3). Also, an estimate of the amount of health risk assessment (hazard index) of Cr, Ni, Pb, and Zn of heavy metal exposure to participants was used. Result of this study showed that the residential and industrial areas had the lowest and the highest level of heavy metal. Based on the result of this study, average levels of heavy metal in industrial, high-traffic, and residential areas in autumn and winter were 31.48, 30.89, and 23.21 μg m-3 and 42.60, 37.70, and 40.07 μg m-3, respectively. Based on the result of this study, the highest and the lowest concentration of heavy metal had in the industrial and residential areas. Zn and Pb were the most abundant elements among the studied PM10-bound heavy metals, followed by Cr and Ni. The carcinogenic risks of Cr, Pb, and the integral HQ of metals in PM10 for children and adults via inhalation and dermal exposures exceeded 1 × 10-4 in three areas. Also, based on the result of this study, the values of hazard index (HI) of HM exposure in different areas were significantly higher than standard. The health risks attributed to HM should be further investigated from the perspective of the public health in metropolitans. The result of this study showed increasing exposure concentrations to heavy metal in the studied scenarios have a significant potential for generating different health endpoints, while environmental health management in ambient air can cause disorders in citizenship and causing more spiritual and material costs.

Environmental impact of heavy metals on the soils and plants around a coke-making factory of Jiyuan city, China

NASA Astrophysics Data System (ADS)

Lun Leung, Kwun

2010-05-01

The combustion of coal usually leads to many different kinds of pollution around coke-making factories. Among these pollutions, the heavy metal contamination in the soil and plants is one of the major concerns by people living around. Heavy metals are highly attracted to the biological tissue, and can stay in bodies of organisms for long period of time, causing a lot of hazardous diseases to human beings, animal and plants. In the developing regions of China, developing of industries has been based on the sacrifices of environments and human health. In order to evaluate the danger of heavy metal contamination from a coke factory to citizens of close inhabitants, a survey on soil and plants was conducted in the region around a coke-making factory in Jiyuan city, which is a major electricity supplying city for the Henan Province in China. In this study, 8 surface soil samples and 11 plant samples were collected from 8 different places around the coke-making factory in Jiyuan city. The collected samples are then treated in the laboratory, and 8 types of heavy metals, which include arsenic, cadmium, chromium, cobalt, copper, lead, nickel and zinc, are analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The concentration data of heavy metals that collected from the analysis are then used to evaluate their toxicity towards living organisms and ecology by applying several biological effect standards, such as effect-range low (ERL), effect-range median (ERM) and several maximum allowances standards of heavy metal concentrations in soils and plants that established by different countries. Moreover, the relationship between the distance from the factory and the concentration of heavy metals in soils and plants are also evaluated in order to find out the contamination ranges of those heavy metals from the source. The result shows that the concentration of these 8 types of heavy metals in the site exceeds the ERL, with lead being the heavy metals that exceeds the biological effect standards the most. This study suggests some remediate measures that must be made in order to decrease the emission of these elements to meet the national standards. The local government is now realized the problems and begins to limit the emissions and offers medical treatments to kids detected with high blood lead.

Distribution and health risk assessment of dissolved heavy metals in the Three Gorges Reservoir, China (section in the main urban area of Chongqing).

PubMed

Zhao, Xin; Li, Ting-Yong; Zhang, Tao-Tao; Luo, Wei-Jun; Li, Jun-Yun

2017-01-01

The Three Gorges Project (TGP) is the largest hydropower station ever built in the world. A better understanding of the concentrations of heavy metals in the aquatic environment of the Three Gorges Reservoir (TGR) is crucial for national drinking water security and sustainable ecosystem development. To thoroughly investigate the impact of heavy metals on water quality after the impoundment to the maximum level of 175 m in the TGR, the concentrations of the dissolved heavy metals (Cr, Cu, Zn, Cd, Pb, As) were measured in April and August 2015, by inductively coupled plasma mass spectrometry (ICP-MS). (1) Except Zn and Pb, most of the heavy metal concentrations in the water of the TGR reached the level of the National Surface Water Environmental Quality Standards (GB3838-2002) I of China, revealing that the water quality of the TGR was good overall. (2) There were significant positive correlations among the concentrations of Cu, As, and Cd, revealing that they may exhibit similar geochemical behaviors. (3) The spatial distribution of the heavy metal concentrations was diverse and complex. The Zn concentration obviously increased in the rainy season from upstream to downstream in the Yangtze River, while the other heavy metals exhibited no significant changes in their concentrations. The distribution characteristics of the heavy metal concentrations on both sides and the middle of the river were different at different sites. (4) The health risk of the six elements was assessed through a human health risk assessment (HHRA), and the assessment results were lower than the maximum acceptable risk level designed by the US EPA and International Commission on Radiological Protection (ICRP). The HHRA model in the aquatic environment revealed that the risk of non-carcinogenic heavy metals (Cu, Zn, and Pb) was at a negligible risk level of 10 -11 ∼10 -9  a -1 . At all the study sites, the risk of carcinogenic heavy metals (Cr, Cd, and As) was higher than the risk of non-carcinogenic heavy metals. As was the most important risk factor, followed by Cr. The results of this study hold great significance for a timely understanding of the changing water quality for affected departments to ensure the health of the residents in the TGR area.

Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum

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

Kim, Jin Woo; Lee, Won Suk; Byun, Jong Min

2015-05-07

We employed a modified refractory-metal-addition method to achieve higher coercivity and remanence in heavy rare earth element (HREE)-free Nd–Fe–B sintered magnets. This process involved inducing the formation of a homogeneous secondary phase at the grain boundaries during sintering, making it possible to control the intergrain diffusion by adding small amounts of Mo, a refractory metal. To control the microstructure of the secondary phase effectively, a metal organic compound of the refractory metal was coated on the surfaces of the particles of an HREE-free Nd–Fe–B powder. The average grain size after this process was 5.60 μm, which was approximately 1.8 μm smaller thanmore » that of the HREE-free sintered Nd–Fe–B magnets (7.4 μm). The coercivity of the magnets prepared through this process could be increased from 11.88 kOe to 13.91 kOe without decreasing their remanence.« less

Magnetocaloric effect in heavy rare-earth elements doped Fe-based bulk metallic glasses with tunable Curie temperature

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

Li, Jiawei; Huo, Juntao; Chang, Chuntao, E-mail: ctchang@nimte.ac.cn, E-mail: dujun@nimte.ac.cn

2014-08-14

The effects of heavy rare earth (RE) additions on the Curie temperature (T{sub C}) and magnetocaloric effect of the Fe-RE-B-Nb (RE = Gd, Dy and Ho) bulk metallic glasses were studied. The type of dopping RE element and its concentration can easily tune T{sub C} in a large temperature range of 120 K without significantly decreasing the magnetic entropy change (ΔS{sub M}) and refrigerant capacity (RC) of the alloys. The observed values of ΔS{sub M} and RC of these alloys compare favorably with those of recently reported Fe-based metallic glasses with enhanced RC compared to Gd{sub 5}Ge{sub 1.9}Si{sub 2}Fe{sub 0.1}. The tunable T{submore » C} and large glass-forming ability of these RE doped Fe-based bulk metallic glasses can be used in a wide temperature range with the final required shapes.« less

The effects of fire temperatures on water soluble heavy metals.

NASA Astrophysics Data System (ADS)

Pereira, P.; Ubeda, X.; Martin, D. A.

2009-04-01

Fire ash are majority composed by base cations, however the mineralized organic matter, led also available to transport a higher quantity of heavy metals that potentially could increase a toxicity in soil and water resources. The amount availability of these elements depend on the environment were the fire took place, burning temperature and combusted tree specie. The soil and water contamination from fire ash has been neglected, because the majority of studies are focused on base cations dynamic. Our research, beside contemplate major elements, is focused in to study the behavior of heavy metals released from ash slurries created at several temperatures under laboratory environment, prescribed fires and wildland fires. The results presented in these communication are preliminary and study the presence of Aluminium (Al3+), Manganese (Mn2+), Iron (Fe2+) and Zinc (Zn2+) of ash slurries generated in laboratory environment at several temperatures (150°, 200°, 250°, 300°, 350°, 400°,450°, 500°, 550°C) from Quercus suber, Quercus robur, Pinus pinea and Pinus pinaster and from a low medium temperature prescribed fire in a forest dominated Quercus suber trees. We observed that ash produced at lower and medium temperatures (<300-400°C) released in water higher contents of Al3+ than unburned sample, especially in Quercus species and Mn2+ in Pinus ashes. Fe2+ and Zn2+ showed a reduced concentration in test solution in relation to unburned sample at all temperatures of exposition. In the results obtained from prescribed fire, we identify a higher release of Al3+ and a decrease of the remain elements. The solubilization of these elements are related with pH levels and ash calcite content, because their ability to capture ions in solution. Moreover, the amount and the type of ions released in relation to unburned sample vary in each specie. In this study Al3+ release is related with Quercus species and Mn2+ with Pinus species. Fire ashes can be an environmental problem, because at long term can increase soil acidity. After all base cations have being leached, pH values decrease, and the heavy metals remaining in the ash are easily transported with unknown impacts on soil and water resources. Research is needed in the study at long term of the effects of fire in metals accumulation in soil resources, and all these aspects will be discussed. Keywords: Fire ash, heavy metals, Quercus suber, Quercus robur, Pinus pinea, Pinus pinaster, prescribed fire, pH, Calcite

Statistical Evaluation and Optimization of Factors Affecting the Leaching Performance of Copper Flotation Waste

PubMed Central

Çoruh, Semra; Elevli, Sermin; Geyikçi, Feza

2012-01-01

Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5 min, and temperature = 41.5°C. PMID:22629194

Statistical evaluation and optimization of factors affecting the leaching performance of copper flotation waste.

PubMed

Coruh, Semra; Elevli, Sermin; Geyikçi, Feza

2012-01-01

Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5 min, and temperature = 41.5 °C.

Trace elemental composition of curry by inductively coupled plasma optical emission spectrometry (ICP-OES).

PubMed

Gonzálvez, A; Armenta, S; De La Guardia, M

2008-01-01

A methodology based on inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted acid digestion was developed to determine the content of traces elements in curry samples from the Spanish market. The methodology was validated in terms of accuracy by the analysis of citrus and tomato leaf reference materials achieving comparable results with the certified values. The trace metal content of curry samples was compared with data available from previously published reports concerning Indian samples, especially in terms of heavy metal composition, in order to guarantee the quality of the commercially available spices in the European countries. Values found for the analysis of arsenic, lead and cadmium were significantly lower than the maximum limit allowed by European Union statutory limits for heavy metals and lower than those obtained for Indian curry leaves reported by Indian research teams by using neutron activation and γ-ray analysis.

Identification of heavy metals on vegetables at the banks of Kaligarang river using neutron analysis activation method

NASA Astrophysics Data System (ADS)

Yulianti, D.; Marwoto, P.; Fianti

2018-03-01

This research aims to determine the type, concentration, and distribution of heavy metals in vegetables on the banks river Kaligarang using Neutron Analysis Activation (NAA) Method. The result is then compared to its predefined threshold. Vegetable samples included papaya leaf, cassava leaf, spinach, and water spinach. This research was conducted by taking a snippet of sediment and vegetation from 4 locations of Kaligarang river. These snippets are then prepared for further irradiated in the reactor for radioactive samples emiting γ-ray. The level of γ-ray energy determines the contained elements of sample that would be matched to Neutron Activation Table. The results showed that vegetablesat Kaligarang are containing Cr-50, Co-59, Zn-64, Fe-58, and Mn-25, and well distributed at all research locations. Furthermore, the level of the detected metal elements is less than the predefined threshold.

Trends and sources for heavy metals in urban atmosphere

NASA Astrophysics Data System (ADS)

Kemp, Kåre

2002-04-01

The concentrations of a number of heavy metals in the air in three Danish cities have been measured by means of PIXE for more than two decades. The well-known capability of PIXE for fast and efficient analysis of aerosol samples has been employed for analysis of daily samples from several sites during the whole period. The main sources are traffic, domestic heating and long-range transport. Source apportionment and trends for single metals are assessed by means of simple statistical methods. The most striking change has occurred for the Pb concentration, which is reduced by almost a factor of 100 following the reduction of the Pb content in petrol. The main source of Cu, Cr and Zn is the traffic. The concentrations of these elements have been slightly increasing. The concentrations for most of the other heavy metals, which originate mainly from sources outside the cities, have been decreasing.

Distribution, enrichment and accumulation of heavy metals in coastal sediments of Alang-Sosiya ship scrapping yard, India.

PubMed

Reddy, M Srinivasa; Basha, Shaik; Sravan Kumar, V G; Joshi, H V; Ramachandraiah, G

2004-06-01

Since its inception in 1982, the Alang-Sosiya yard has become the largest ship scrapping works in the world. Several hundreds of ships arrive every year. The degree of heavy metal contamination has been studied in bulk and fine sediments from the intertidal zone of this ship scrapping yard, two stations, one on either side at 5 km distance and one reference station 60 km distance near Mahuva, towards the south. The samples have been subjected to a total digestion technique and analysed for elements: Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Zn and Al, and %TOC. The absolute metal concentrations reflected variations in BF and FF sediment samples with organic matter content. Enrichment factors (EF) and geoaccumulation indices (Igeo) have been calculated and the relative contamination levels are assessed at these sites. At Alang-Sosiya, the enrichment of heavy metals has been observed to be relatively high.

Differentiation characteristics and source analysis of heavy metals in typical brown soil under different vegetation

NASA Astrophysics Data System (ADS)

Dong, Zhicheng; Zhang, Lina; Li, Xueshuang; Lv, Shuangyan; He, Shijie; Liu, Ying; Ma, Xuanxuan

2017-08-01

Anomalous enrichment of soil elements (especially heavy metals) has aroused popular attention in China. In order to discuss distribution characteristics and analyze sources of elements in brown soil, field investigation and sample collection were carried out under different vegetation (cherry, apple, bamboos and pine) in Qixia, a typical apple production base in China. Element contents, pH, electrical conductivity (EC) and magnetic susceptibility (MS) were tested. Results showed that element concentrations were about roughly 2.48 times as China’s background values, while significantly lower than the class ii of National soil Environment Quality Standard (Ni excepted). Meanwhile, vertical distribution and accumulation characteristics of elements in typical brown soil were significantly different under different vegetation. In detail, elements (Zn excepted) of Pine soil accumulated in surface, while they (Cd, Arsenic excepted) increased with depth under other vegetation. Moreover, pH and EC changed like elements, while MS was exactly opposite. It was found that those differences above were mainly caused by human activities (such as improper use of fertilizer, pesticide and inadequate use of organic fertilizer, etc.). Additionally, differences in composition and decomposition rate of vegetation litter also resulted in vertical differentiations of soil elements under different vegetation.

Heavy metals and essential elements in Italian cereals.

PubMed

Brizio, P; Benedetto, A; Squadrone, S; Curcio, A; Pellegrino, M; Ferrero, M; Abete, M C

2016-12-01

Crops intended for human nutrition and food production containing different essential trace elements, such as copper and zinc, could be contaminated by toxic metals like cadmium and lead. The interrelationship between micronutrients and contaminant trace elements in different cereals was investigated in North-western Italy, where both agricultural and industrial activities are present. Elemental concentrations in sampled cereals were assessed by inductively coupled plasma mass spectrometry (ICP-MS). Rice, oats and barley reached the highest median levels for Al, Cd and Pb content, while corn samples were less contaminated by toxic metals. Regarding essential elements highest median values of Cu and Zn were both found in barley, while Ni median content was higher in oats. Rice had the lowest median levels of essential elements. The correlation study between toxic and essential elements seemed to demonstrate fixed trends in analysed samples, corroborating the importance of a different diet to limit potential adverse effects caused by toxic elements.

Analysis of Carcinogenic Heavy Metals in Gallstones and its Role in Gallbladder Carcinogenesis.

PubMed

Mondal, Bikash; Maulik, Dhrubajyoti; Mandal, Mousumi; Sarkar, Gautam Narayan; Sengupta, Sanjay; Ghosh, Debidas

2017-12-01

Gallstone is a high-risk factor for gallbladder pre-malignancy or malignancy (GB PM-M) but which substances of gallstones definitely assist to turn out in to GB PM-M, remains unclear. This study aimed to find out the presence of carcinogenic heavy metals in gallstones and to explore the aetiopathogenesis of gallbladder pre-malignancy and malignancy. Presence of elements in gallstones was detected by energy dispersive X-ray spectroscopy (EDS) with scanning electron microscopy (SEM) and then level of carcinogenic heavy metals was estimated in gallstones using atomic absorption spectroscopy (AAS). The experiment was carried out in gallstone samples of 46 patients with gallbladder pre-malignant and malignant condition (PM-M group) and 65 sex and age-matched patients with chronic cholecystitis (C-C group). Gallstones were also classified in to three types such as cholesterol stone, mixed stone, and black pigment stone. EDS analysis detected presence of mercury, lead, and cobalt elements in all types of gallstones of both PM-M and C-C groups. AAS analysis revealed significantly higher amount of mercury (p < 0.001), lead (p < 0.0001), cobalt (p < 0.01), and cadmium (p < 0.01) in the gallstones of PM-M than C-C groups. The presence of these heavy metals also varied among stone types of both groups. EDS phase analysis showed 'dense deposits' of these metals in gallstones. Presence of significantly higher amount of mercury, lead, cobalt, and cadmium in gallstones may play a pivotal role as risk factors in the development of gallbladder malignancy or pre-malignancy. 'Dense deposits' of these metals in the gallstones which is the first observation, may act as crucial doses of carcinogens.

Growth conditions, elemental accumulation and induced physiological changes in Chinese cabbage.

PubMed

Moreno, Diego A; Víllora, Gemma; Ruiz, Juan M; Romero, Luis

2003-08-01

Soils contaminated with low levels of heavy metals and other trace elements are now frequently used for vegetable growing. In this situation, heavy metals and trace elements from these polluted soils may accumulate in the agricultural plants being grown in them and thereby enter the human food chain. The objectives of this study are to elucidate the effects of growth conditions, manipulated by the crop covers, on the phytoaccumulation of elements, and to investigate the conceivable influences of these conditions on the plant biochemistry. In three consecutive years of field experiments, open air (T(0)), and floating rowcover treatments (T(1): perforated polyethylene 50 micrometers; T(2): polypropylene 17 gm(-2)) were used to produce different environmental conditions for the growth of Chinese cabbage [Brassica rapa L. (Pekinensis group) cv. 'Nagaoka 50']. Five samplings (whole tops) were carried out from transplanting to harvest and measurements of B, Al, Ag, Si and Ca concentration as well as phenolics (orto-diphenols, total phenols and anthocyanins), pectic fractions, amino acids (histidine, phenylalanine and tyrosine) and polyphenol oxidase activity, were carried out in samples. The T(1) (perforated polyethylene sheet) gave greater B, Al, Ag and Si concentration and phytoextraction (in weight units) than the open-air control. These findings can help to develop new cost-effective techniques for phytoremediation as the application of plastic covers in the field. The build-up of heavy metals in those crops would make the product less suitable for human consumption.

Multielemental analysis of Migori (Southwest, Kenya) artisanal gold mine ores and sediments by EDX-ray fluorescence technique: implications of occupational exposure and environmental impact.

PubMed

Odumo, O B; Mustapha, A O; Patel, J P; Angeyo, H K

2011-05-01

The results of heavy element profiling of the gold ores and sediments associated with the artisanal gold mining activities of the Migori gold belt of Southwestern Nyanza, Kenya, were reported in this paper. The analysis was made to assess the occupational exposure of the miners as well as to investigate the environmental impact of toxic heavy metals. Gold ores and sediments from the artisanal gold processing were sampled in four artisanal gold mining areas: Osiri A, Osiri B, Mikei and Macalder (Makalda) and analyzed for heavy elemental content using (109)Cd radioisotope excited EDXRF spectrometry technique. Analysis consisted of direct irradiating of sample pellets. The concentrations of major elements detected were: titanium (711.41-10,766.67 mg/kg); cobalt (82.65-1,010.00 mg/kg); zinc (29.90-63,210 mg/kg); arsenic (29.30-8,246.59 mg/kg); gold (14.07-73.48 mg/kg); lead (16.31-14,999.40 mg/kg) and mercury (16.10-149.93 mg/kg). The average concentration of the heavy toxic metals i.e. arsenic, lead, titanium and zinc were found to be above 50 mg/Kg as recommended by World Health Organization. © Springer Science+Business Media, LLC 2011

Mineral resource of the month: rare earth elements

USGS Publications Warehouse

,

2011-01-01

The article provides information on rare earth elements, which are group of 17 natural metallic elements. The rare earth elements are scandium, yttrium and lanthanides and classified into light rare earth elements (LREE) and heavy rate earth elements (HREE). The principal ores of the rare earth elements are identified. An overview of China's production of 97 percent of the rare earths in the world is provided. Commercial applications of rare earths are described.

Evolution of heavy-element abundances in the Galactic halo and disk

NASA Technical Reports Server (NTRS)

Mathews, G. J.; Cowan, J. J.; Schramm, D. N.

1988-01-01

The constraints on the universal energy density and cosmological constant from cosmochronological ages and the Hubble age are reviewed. Observational evidence for the galactic chemical evolution of the heavy-element chronometers is descirbed in the context of numerical models. The viability of the recently discovered Th/Nd stellar chronometer is discussed, along with the suggestion that high r-process abundances in metal-poor stars may have resulted from a primordial r-process, as may be required by some inhomogeneous cosmologies.

Spatiotemporal Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 in Zhejiang Province

PubMed Central

Wang, Xiaofeng; He, Shengliang; Chen, Shuchang; Zhang, Yongli; Wang, Aihong; Luo, Jinbin; Ye, Xialiang; Mo, Zhe; Wu, Lizhi; Xu, Peiwei; Cai, Gaofeng; Chen, Zhijian; Lou, Xiaoming

2018-01-01

The spatiotemporal characteristics and human health risks of 12 heavy metals (Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb, Se, and Tl) in fine particulate matter (PM2.5) in Zhejiang Province were investigated. The annual average PM2.5 concentration was 58.83 µg/m3 in 2015 in Zhejiang. Element contents in PM2.5 varied greatly with the season and locations. Al, Pb, and Mn were the most abundant elements among the studied metal(loid)s in PM2.5. The non-carcinogenic risks of the 12 elements through inhalation and dermal contact exposure were lower than the safe level for children and adults. However, there were potential non-carcinogenic risks of Tl, As, and Sb for children and Tl for adults through ingestion exposure. The carcinogenic risks from As, Be, Cd, Cr, Pb, and Ni through inhalation exposure were less than the acceptable level (1 × 10−4) for children and adults. Pb may carry a potential carcinogenic risk for both children and adults through ingestion. More attention should be paid to alleviate non-carcinogenic and carcinogenic health risks posed by particle-bound toxic elements through ingestion exposure. PMID:29587346

Effects of compost fertilization in organic farming on micronutrients and heavy metals in soil and crops

NASA Astrophysics Data System (ADS)

Erhart, Eva; Sager, Manfred; Bonell, Marion; Fuchs, Katrin; Haas, Dieter; Ableidinger, Christoph; Hartl, Wilfried

2015-04-01

For organic stockless and vegetable farms using biowaste compost is a way to sustain soil humus content. At the same time compost use in agriculture closes local nutrient cycles. Besides organic matter and main nutrients, biowaste compost also imports micronutrients and heavy metals in amounts determined by the compost input material. The aim of this work was to assess total and plant-available contents of micronutrients B, Ca, Cu, Fe, Mn, Mo, Ni, Zn, beneficial elements Co and Se and heavy metals Cd, Cr and Pb in the soil and in crops after 20 years of fertilization with compost produced from source-separated organic waste. Topsoil and wheat grain samples were collected from the long-term field experiment 'STIKO' situated near Vienna on a Molli-gleyic Fluvisol. Between 1992 and 2012 the organic treatments C1, C2 and C3 had received 5, 10 and 14 t ha-1 yr-1 (wet wt.) biowaste compost on average. They were compared with the unfertilized organic control treatment and with three mineral fertilization treatments, which had received 20, 32 and 44 kg N ha-1 yr 1, respectively, plus 40 kg P and 68 kg K ha-1 yr-1 on average. Total soil element contents of B, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se and Zn were measured in aqua regia digestion. Immediately water-soluble elements were analysed in soil saturation extract, elements in exchangeable form in LiCl extract following Husz (2001), and long-term available elements in 0.5 N HCl extract. Wheat grains were dehulled, milled and subjected to microwave digestion with HNO3 and H2O2. Wheat was analyzed for Cd and Pb with ICP-MS. All other elements in wheat and all soil extracts were analyzed using ICP-AES. Total soil concentrations of micronutrients, heavy metals and beneficial elements were in the range of usual soil contents and lower than the Austrian background values for arable land with comparable pH and carbonate concentration (Schwarz and Freudenschuss, 2004) in all treatments (all mg kg-1: B 14-19, Fe 16000-18000, Mn 397-445, Mo 0.7-1.0, Cu 15-17, Ni 21-22, Zn 45-52, Cr 26-28, Pb 13-17, Co 7.5-8.4). Total soil concentrations of Cd (0.37-0.46 mg kg-1) were the same as the background values. No significant differences were found between the treatments and the unfertilized control. Similarly, the plant available LiCl-fraction and the long-term available HCl-fraction did not show significant differences between the treatments. In the soil saturation extracts, Cu content was 18-22 µg kg-1, B 172-187 µg kg-1, Fe 62-113 µg kg-1 and Ca 62-71 mg kg-1, all in the usual range of soil saturation extracts of agricultural fields without significant differences between treatments. The other elements were below the limit of determination. In the wheat, contents of micronutrients, heavy metals and beneficial elements were in the same range as in other Austrian wheat samples (Spiegel and Sager, 2008) with the exception of Ca. Element contents were (all in mg kg-1): B 0.5-0.6, Ca 387-464, Cd 0.023-0.028, Co 0.006, Cr 0.10-0.17, Cu 4.7-5.3, Fe 36-50, Mn 30-33, Mo 0.31-0.35, Ni 0.11-0.15, Se 0.15-0.27 and Zn 28-31. Pb was below the limit of determination in the wheat grains. No significant differences were detected between the treatments. After 20 years of compost fertilization with high quality biowaste compost at the above rates no increase in micronutrients and heavy metals was detected in total soil contents and in plant-available fractions nor in wheat grains.

H2S adsorption by municipal solid waste incineration (MSWI) fly ash with heavy metals immobilization.

PubMed

Wu, Huanan; Zhu, Yu; Bian, Songwei; Ko, Jae Hac; Li, Sam Fong Yau; Xu, Qiyong

2018-03-01

As a byproduct of municipal solid waste incineration (MSWI) plant, fly ash is becoming a challenge for waste management in recent years. In this study, MSWI fly ash (FA) was evaluated for the potential capacity of odorous gas H 2 S removal. Results showed that fly ash demonstrated longer breakthrough time and higher H 2 S capacities than coal fly ash and sandy soil, due to its high content of alkali oxides of metals including heavy metals. H 2 S adsorption capacities of FA1 and FA2 were 15.89 and 12.59 mg H 2 S/g, respectively for 750 ppm H 2 S. The adsorption of H 2 S on fly ash led to formation of elemental sulfur and metal sulfide. More importantly, the formation of metal sulfide significantly reduced the leachability of heavy metals, such as Cr, Cu, Cd and Pb as shown by TCLP tests. The adsorption isotherms fit well with Langmuir model with the correlation coefficient over 0.99. The adsorption of H 2 S on fly ash features simultaneous H 2 S removal and stabilization and heavy metals found in most MSWI fly ash, making fly ash the potential low cost recycled sorbent material. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Characteristics and Risk Assessment of Heavy Metals in Core Sediments from Lakes of Tibet].

PubMed

Guo, Bi-xi; Liu, Yong-qin; Zhang, Fan; Hou, Ju-zhi; Zhang, Hong-bo

2016-02-15

To explore the source of heavy metals in lake sediments and their hazard to environment on Tibetan Plateau, China, heavy metal (Cu, Zn, Cd, Pb, Cr, Co, Ni and As) levels in surface sediments of 18 lakes were investigated. Inductively Coupled Plasma Mass Spectrometry (ICP-MS, X-7 series) was used to determine the contents of heavy metals and the concentrations of carbon and nitrogen in sediment samples were analyzed by element analyzer (Vario Max CN, Elementar, Germany). The average concentrations for Cu, Zn, Cd, Pb, Cr, Co, Ni and As were 24.61 mg x kg(-1), 70.14 mg x kg(-1), 0.26 mg x kg(-1), 25.43 mg x kg(-1), 74.12 mg x kg(-1), 7.93 mg x kg(-1), 33.85 mg x kg(-1), 77.69 mg x kg(-1). It was found that heavy-metal concentrations in Tibet sediments were higher than those in Antarctic, but lower than those in the regions affected by anthropogenic activities. The contents of Cu, Zn, Pb, Cr and Co in the samples were lower than the background values of Tibet. Correlation analysis and principal components analysis (PCA) were used to analyze the origins of heavy metals. The result showed that Cu, Zn, Cd, Pb, Co, Ni and As came from soil in drainage basin and atmospheric deposition. Cr was mainly affected by human activities. Assessment on ecological risk of heavy metals was carried out using Hakanson's method and cluster analysis (CA). Assessment on ecological risk indicated that Pumoyum Co, Longmo Co and Bangong Co were at low risks, Bieruoze Co was at high ecological risk level and the other lakes were at different risk levels.

Moisture Influence Reducing Method for Heavy Metals Detection in Plant Materials Using Laser-Induced Breakdown Spectroscopy: A Case Study for Chromium Content Detection in Rice Leaves.

PubMed

Peng, Jiyu; He, Yong; Ye, Lanhan; Shen, Tingting; Liu, Fei; Kong, Wenwen; Liu, Xiaodan; Zhao, Yun

2017-07-18

Fast detection of heavy metals in plant materials is crucial for environmental remediation and ensuring food safety. However, most plant materials contain high moisture content, the influence of which cannot be simply ignored. Hence, we proposed moisture influence reducing method for fast detection of heavy metals using laser-induced breakdown spectroscopy (LIBS). First, we investigated the effect of moisture content on signal intensity, stability, and plasma parameters (temperature and electron density) and determined the main influential factors (experimental parameters F and the change of analyte concentration) on the variations of signal. For chromium content detection, the rice leaves were performed with a quick drying procedure, and two strategies were further used to reduce the effect of moisture content and shot-to-shot fluctuation. An exponential model based on the intensity of background was used to correct the actual element concentration in analyte. Also, the ratio of signal-to-background for univariable calibration and partial least squared regression (PLSR) for multivariable calibration were used to compensate the prediction deviations. The PLSR calibration model obtained the best result, with the correlation coefficient of 0.9669 and root-mean-square error of 4.75 mg/kg in the prediction set. The preliminary results indicated that the proposed method allowed for the detection of heavy metals in plant materials using LIBS, and it could be possibly used for element mapping in future work.

Benthic macroalgae as biological indicators of heavy metal pollution in the marine environments: a biomonitoring approach for pollution assessment.

PubMed

Chakraborty, Sukalyan; Bhattacharya, Tanushree; Singh, Gurmeet; Maity, Jyoti Prakash

2014-02-01

Metal pollution in the marine coastline environment is an important topical issue in the context of ecological disturbance and climate change. Heavy metal contaminations (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in seawater and surficial sediments, as well as macroalgal diversity, were determined in six different locations along the coast of the Gulf of Kutch in India. The marine coastline environment was found to be enriched with Cd and Zn in comparison to other metals. Significant (p ≤ 0.05) inter-elemental positive-correlations were observed between Fe-Mn, Fe-Cu, Fe-Cr, Fe-Zn, Cr-Cu, Cu-Mn, and Cd-Zn, as well as negative-correlations between Cd-Pb, Ni-Pb, and Zn-Pb. Though genus specific macroalgal responses to heavy metal accumulation were significant, species specific response was insignificant (p ≤ 0.05). The relative abundance of metals in macroalgae followed the order of Fe>Zn>Mn>Cu>Cd>Cr>Ni>Pb. The high uptake of metals in green algae (Ulva lactuca and Enteromorpha intestinalis) and brown algae (Padina gymnospora and Dictyota bartayresiana) suggested that these algae may be used as potential biomonitors for heavy metal pollution. Three pollution indicators, Contamination Factor (CF), Enrichment Factor (EF) and Geochemical Index (Igeo) were calculated to determine the degree of metal pollution in the marine coastline and the contribution of anthropogenic influence. © 2013 Published by Elsevier Inc.

Heavy metals in hair of wild canids from the Brazilian Cerrado.

PubMed

Curi, Nelson Henrique de Almeida; Brait, Carlos Henrique Hoff; Antoniosi Filho, Nelson Roberto; Talamoni, Sônia Aparecida

2012-06-01

In this study, we aimed to assess whether free-ranging wild canids are exposed to heavy metals in one of the most developed and populated regions of Brazil. Hair of 26 wild canids (maned wolves Chrysocyon brachyurus, crab-eating foxes Cerdocyon thous, and hoary foxes Lycalopex vetulus) from the Cerrado biome in Southeast Brazil were analyzed by spectrophotometry to detect cadmium, chromium, and lead, and also the essential copper, iron, manganese, and zinc traces. All samples showed traces of copper, iron, manganese, and zinc. Non-essential lead was detected in 57% (2.35 ± 0.99 mg/kg), and chromium in 88% (2.98 ± 1.56 mg/kg) of samples. Cadmium traces (detection limit 0.8 mg/kg) were not found. Crab-eating foxes had more copper, iron, and manganese in hair than maned wolves. Correlations among element levels differed between maned wolves and crab-eating foxes. Concentrations of chromium and lead were outstandingly higher than in wild canids from other areas. Addressing the causes of such levels and the impacts of the heavy metal pollution in Neotropical ecosystems is urgent for animal health and conservation purposes. We argue that heavy metal pollution should be considered as dangerous threats to wildlife health in Brazil and recommend hair sampling as a biomonitoring tool for heavy metals in Neotropical terrestrial mammals.

Analysis on the distribution characteristics and sources of soil heavy metals in suburban farmland in Xiangtan City

NASA Astrophysics Data System (ADS)

Zhang, Yong; Sun, Xinxin

2018-01-01

The rapid development of the economy will inevitably have an impact on the farmland soil environment. The content of heavy metal is increasing day by day, and the heavy metal can enter people's body through different channels and endanger people's health. Based on agricultural land and crop types in accordance with the regional land use classification, using the method of the Single Factor Index and Comprehensive Pollution Index, the pollution status of heavy metals in farmland soil in the suburbs of Xiangtan city was studied and evaluated. At the same time, we use SPSS software to analyze the four heavy metal elements (Cu, Zn, As and Pb) and analyze their possible sources. The results showed that the farmland soils in Erhuan Road and Zhubu Port were polluted, and the farmland soil in Shuangma (an old industrial district) was not polluted; for different crop lands, orchards and vegetable lands were not contaminated, but rape and rice lands were contaminated. Pearson correlation analysis showed that Cu, As and Pb might come from the same pollution source, while Zn might come from other sources. Waste water from a chemical plant, crop types, automobile exhaust and other human factors may be important sources of soil pollution in agricultural fields.

Spatial Variation and Assessment of Heavy Metal and Radioactive Risk in Farmland around a Retired Uranium Mine

NASA Astrophysics Data System (ADS)

Liang, Jie; Shi, Chen-hao; Zeng, Guang-ming; Zhong, Min-zhou; Yuan, Yu-jie

2017-07-01

In recent years, heavy metal contamination in the environment has been attracted worldwide attention due to their toxicity, persistence,extensive sources and non-biodegradable properties. We herein investigate variation trend and risk of heavy metal and radiation distribution in the former mine stope, former mineral ore stockyard, and mine road with surface soils of a retired uranium mine in the mid-south of China. The mean concentrations (mg/kg) of Pb,Cd,Cu,Zn,As,Hg,Cr,Mn,Ni,U, and 232Th were analyzed according to the corresponding background values in Hunan, China. The Geo-accumulation index (Igeo ) were used for the assessment of pollution level of heavy metals and the radioactive elements of U and 232Th. Then, Pollution load index (PLI) and GIS techniquewere integrated to assess spatial distribution of heavy metal contamination and radioactive contamination. Results confirmed that three areas in the retired uranium mine was a primary source of pollution, which showed anthropogenic origin mainly from agricultural runoff, hydrometallurgy from chemical industries, radioactive tailings, and electroplating industriesfinally drained into Zishui River and Xiangjiang River. Based on the actual situation, some suggestions were put forward for the treatment of the retired uranium mine in conclusion.

Enrichment and assessment of the health risks posed by heavy metals in PM1 in Changji, Xinjiang, China.

PubMed

Liu, Yu Y; Shen, Ya X; Liu, Cheng; Liu, Hao F

2017-04-16

The present study aims to investigate the influence of human activity on heavy metals in a typical arid urban area of China and assess human health risks posed by heavy metals in PM 1 (particles <1.0 μm in diameter) for different people. In this paper, Changji (Xinjiang, China) was selected as the study area, and samples were collected from March 2014 to March 2015. A total 14 elements in PM 1 were quantified using ICP-MS. An enrichment factor (EF) was used to assess the influence of human activity on the contamination of these metals. The results indicated that Mn was not enriched; Co, Cu, Cr, Ni, Tl, and V were slightly enriched; Mo, Pb, and Sb were moderately enriched; and Ag, As, and Cd were strongly enriched. To assess the health risks associated with inhaling PM 1 , the risk assessment code and loss in life expectancy based on the individual metals were calculated. The results showed that the elements Ag, Cu, Mo, Pb, Sb, Tl, and V in PM 1 posed low levels of non-carcinogenic risks, but these metals may still pose risks to certain susceptible populations. In addition, the results also showed that As, Co, and Cr posed an appreciable carcinogenic risk, while Cd and Ni posed low levels of carcinogenic risk. The total predicted loss of life expectancy caused by the three metals As, Co, and Ni was 63.67 d for the elderly, 30.95 d for adult males, 26.62 d for adult females, and 48.22 d for children. Therefore, the safety of the elderly and children exposed to PM 1 should be given more attention than the safety of adults. The results from this study demonstrate that the health risks posed by heavy metals in PM 1 in Changji, Xinjiang, China should be examined.

Associations of urban environmental pollution with health-related physiological traits in a free-living bird species.

PubMed

Bauerová, Petra; Vinklerová, Jitka; Hraníček, Jakub; Čorba, Vojtěch; Vojtek, Libor; Svobodová, Jana; Vinkler, Michal

2017-12-01

Urban environmental pollution results in contamination of the tissues of synanthropic organisms by toxic trace elements with potential impacts on human health. Passerine birds may serve as convenient indicators of such contamination. In this study we investigated the effect of blood and plumage contamination with heavy metals (lead Pb, cadmium Cd, copper Cu, chromium Cr) and arsenic metalloid (As) on condition, health and ornamental colour in free-living great tit (Parus major) males from 13 cities across the Czech Republic (EU), mist netted during the early breading season (April-May). Our results showed a significant association of heavy metal tissue contamination with immune function, namely leukocyte composition in the avian blood circulation. High heavy metal contamination in bird feathers was linked to a high heterophil/lymphocyte (H/L) ratio, indicating long-term stress in individuals inhabiting heavily polluted environments. In contrast, males with higher concentrations of heavy metals in blood had a lower H/L ratio, assumingly due to the direct toxicity of heavy metals in certain cell types. This is also supported by traits indicative of anaemia-like haemolytic conditions (decreased absolute erythrocyte count) and increased haematopoiesis (a tendency for increased frequencies of immature erythrocytes). We did not find any association of heavy metal contamination with the bacteriolytic activity of plasma complement, feather growth or ornamentation (black breast stripe area and yellow colouration). There was no significant relationship between heavy metal contamination in blood or feathers and PM 10 pollution at the study sites. Our correlational study is the first to show on a large geographic scale that despite strict European air pollution regulations and regular monitoring that have allowed general improvements in atmospheric contamination, non-degradable heavy metals persistently contaminate animal blood and feathers in anthropogenic environments at levels that may have subclinical yet physiological effects with varied influence on health. Copyright © 2017 Elsevier B.V. All rights reserved.

Heavy metal toxicity as a kill mechanism in impact caused mass extinctions

NASA Technical Reports Server (NTRS)

Wdowiak, T. J.; Davenport, S. A.; Jones, D. D.; Wdowiak, P.

1988-01-01

Heavy metals that are known to be toxic exist in carbonaceous chrondrites at abundances considerably in excess to that of the terrestrial crust. An impactor of relatively undifferentiated cosmic matter would inject into the terrestrial environment large quantities of toxic elements. The abundances of toxic metals found in the Allende CV carbonaceous chondrite and the ratio of meteoritic abundance to crustal abundance are: Cr, 3630 PPM, 30X; Co, 662 PPM, 23X; ni, 13300 PPm, 134X; se, 8.2 PPM, 164X; Os, 0.828 PPM, 166X. The resulting areal density for global dispersal of impactor derived heavy metals and their dilution with terrestrial ejecta are important factors in the determination of the significance of impactor heavy metal toxicity as a kill mechanism in impact caused mass extinctions. A 10 km-diameter asteroid having a density of 3 gram per cu cm would yield a global areal density of impact dispersed chondritic material of 3 kg per square meter. The present areal density of living matter on the terrestrial land surface is 1 kg per square meter. Dilution of impactor material with terrestrial ejecta is determined by energetics, with the mass of ejecta estimated to be in the range of 10 to 100 times that of the mass of the impactor. Because a pelagic impact would be the most likely case, the result would be a heavy metal rainout.

Halophytes--an emerging trend in phytoremediation.

PubMed

Manousaki, Eleni; Kalogerakis, Nicolas

2011-01-01

Halophytic plants are of special interest because these plants are naturally present in environments characterized by an excess of toxic ions, mainly sodium and chloride. Several studies have revealed that these plants may also tolerate other stresses including heavy metals based on the findings that tolerance to salt and to heavy metals may, at least partly, rely on common physiological mechanisms. In addition, it has been shown that salt-tolerant plants may also be able to accumulate metals. Therefore, halophytes have been suggested to be naturally better adapted to cope with environmental stresses, including heavy metals compared to salt-sensitive crop plants commonly chosen for phytoextraction purposes. Thus, potentially halophytes are ideal candidates for phytoextraction orphytostabilization of heavy metal polluted soils and moreover of heavy metal polluted soils affected by salinity. Some halophytes use excretion processes in order to remove the excess of salt ions from their sensitive tissues and in some cases these glandular structures are not always specific to Na+ and Cl- and other toxic elements such as cadmium, zinc, lead, or copper are accumulated and excreted by salt glands or trichomes on the surface of the leaves--a novel phytoremediation process called "phytoexcretion". Finally, the use of halophytes has also been proposed for soil desalination through salt accumulation in the plant tissue or dissolution of soil calcite in the rhizosphere to provide Ca2+ that can be exchanged with Na+ at cation exchange sites.

Groundwater chemistry and human health risk assessment in the mining region of East Singhbhum, Jharkhand, India.

PubMed

Singh, Umesh Kumar; Ramanathan, A L; Subramanian, V

2018-08-01

Groundwater chemistry of mining region of East Singhbhum district having complex contaminant sources were investigated based on heavy metals loads and other hydrochemical constituents. This study aimed to identify the degree of heavy metals exposure and their potential health risk to local population. The results of hydrochemical analysis showed that Na + , K + , and Ca 2+ ions are the dominant cations in the groundwater, while HCO 3 - , F - and Cl - ions dominate the anionic part of the groundwater. The weathering process was considered the dominant factor to determine the major ionic composition in the study area. Compositional analysis for heavy metal has identified that groundwater of the study area is contaminated by Cd, Pb and Cr elements. Source of these metals have been identified as an anthropogenic inputs from mining activities and mineral processing units. Health risk analysis of individual heavy metal for chronic daily intake (CDI) and hazard quotient (HQ) was found in the order of Cr > As > Cd > Pb which is indicating high health risk for the population. In addition, Hazard Index (HI) analysis for heavy metals was found significantly high (>1) which is considered as a threat for human population because they have the tendency to accumulate in the body and cause variety of diseases like kidney problem, dysfunction of liver and renal cortex as well as cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modeling and evaluation of urban pollution events of atmospheric heavy metals from a large Cu-smelter.

PubMed

Chen, Bing; Stein, Ariel F; Castell, Nuria; Gonzalez-Castanedo, Yolanda; Sanchez de la Campa, A M; de la Rosa, J D

2016-01-01

Metal smelting and processing are highly polluting activities that have a strong influence on the levels of heavy metals in air, soil, and crops. We employ an atmospheric transport and dispersion model to predict the pollution levels originated from the second largest Cu-smelter in Europe. The model predicts that the concentrations of copper (Cu), zinc (Zn), and arsenic (As) in an urban area close to the Cu-smelter can reach 170, 70, and 30 ng m−3, respectively. The model captures all the observed urban pollution events, but the magnitude of the elemental concentrations is predicted to be lower than that of the observed values; ~300, ~500, and ~100 ng m−3 for Cu, Zn, and As, respectively. The comparison between model and observations showed an average correlation coefficient of 0.62 ± 0.13. The simulation shows that the transport of heavy metals reaches a peak in the afternoon over the urban area. The under-prediction in the peak is explained by the simulated stronger winds compared with monitoring data. The stronger simulated winds enhance the transport and dispersion of heavy metals to the regional area, diminishing the impact of pollution events in the urban area. This model, driven by high resolution meteorology (2 km in horizontal), predicts the hourly-interval evolutions of atmospheric heavy metal pollutions in the close by urban area of industrial hotspot.

Uptake of heavy metals by Typha capensis from wetland sites polluted by effluent from mineral processing plants: implications of metal-metal interactions.

PubMed

Zaranyika, M F; Nyati, W

2017-10-01

The aim of the present work was to demonstrate the existence of metal-metal interactions in plants and their implications for the absorption of toxic elements like Cr. Typha capensis , a good accumulator of heavy metals, was chosen for the study. Levels of Fe, Cr, Ni, Cd, Pb, Cu and Zn were determined in the soil and roots, rhizomes, stems and leaves of T. capensis from three Sites A, B and C polluted by effluent from a chrome ore processing plant, a gold ore processing plant, and a nickel ore processing plant, respectively. The levels of Cr were extremely high at Site A at 5415 and 786-16,047 μg g -1 dry weight in the soil and the plant, respectively, while the levels of Ni were high at Site C at 176 and 24-891 μg g -1 in the soil and the plant, respectively. The levels of Fe were high at all three sites at 2502-7500 and 906-13,833 μg g -1 in the soil and plant, respectively. For the rest of the metals, levels were modest at 8.5-148 and 2-264 μg g -1 in the soil and plant, respectively. Pearson's correlation analysis confirmed mutual synergistic metal-metal interactions in the uptake of Zn, Cu, Co, Ni, Fe, and Cr, which are attributed to the similarity in the radii and coordination geometry of the cations of these elements. The implications of such metal-metal interactions (or effects of one metal on the behaviour of another) on the uptake of Cr, a toxic element, and possible Cr detoxification mechanism within the plant, are discussed.

[Distribution Characteristics and Source Analysis of Dustfall Trace Elements During Winter in Beijing].

PubMed

Xiong, Qiu-lin; Zhao, Wen-ji; Guo, Xiao-yu; Chen, Fan-tao; Shu, Tong-tong; Zheng, Xiao-xia; Zhao, Wen-hui

2015-08-01

The dustfall content is one of the evaluation indexes of atmospheric pollution. Trace elements especially heavy metals in dustfall can lead to risks to ecological environment and human health. In order to study the distribution characteristics of trace elements, heavy metals pollution and their sources in winter atmospheric dust, 49 dustfall samples were collected in Beijing City and nearby during November 2013 to March 2014. Then the contents (mass percentages) of 40 trace elements were measured by Elan DRC It type inductively coupled plasma mass (ICP-MS). Test results showed that more than half of the trace elements in the dust were less than 10 mg x kg(-1); about a quarter were between 10-100 mg x kg-1); while 7 elements (Pb, Zr, Cr, Cu, Zn, Sr and Ba) were more than 100 mg x kg(-1). The contents of Pb, Cu, Zn, Bi, Cd and Mo of winter dustfall in Beijing city.were respectively 4.18, 4.66, 5.35, 6.31, 6.62, and 8.62 times as high as those of corresponding elements in the surface soil in the same period, which went beyond the soil background values by more than 300% . The contribution of human activities to dustfall trace heavy metals content in Beijing city was larger than that in the surrounding region. Then sources analysis of dustfall and its 20 main trace elements (Cd, Mo, Nb, Ga, Co, Y, Nd, Li, La, Ni, Rb, V, Ce, Pb, Zr, Cr, Cu, Zn, Sr, Ba) was conducted through a multi-method analysis, including Pearson correlation analysis, Kendall correlation coefficient analysis and principal component analysis. Research results indicated that sources of winter dustfall in Beijing city were mainly composed of the earth's crust sources (including road dust, construction dust and remote transmission of dust) and the burning of fossil fuels (vehicle emissions, coal combustion, biomass combustion and industrial processes).

Ecosystem and human health assessment in relation to aquatic environment pollution by heavy metals: case study of the Murmansk region, northwest of the Kola Peninsula, Russia

NASA Astrophysics Data System (ADS)

Moiseenko, T. I.; Morgunov, B. A.; Gashkina, N. A.; Megorskiy, V. V.; Pesiakova, A. A.

2018-06-01

Throughout the Euro-Arctic region of Russia (Murmansk region), there is a substantial increase of metal concentrations in water, which are related to local discharges from the metallurgical and mining industry, transboundary pollution, as well as indirect leaching of elements by acid precipitation. This study collates data to investigate the relationship between surface water contamination by metals, and fish and human health. Fish are used as a biological indicator to show the impact of water pollution by metals on the ecosystem’s health. The etiology of fish and human diseases are related to the water pollution and accumulation of metals in organisms. High concentrations of Ni and Cd in water drives an accumulation of these elements in organs and tissues of fish, especially in kidneys. The relation between the accumulation of Ni in kidneys and the development of fish nephrocalcinosis and fibroelastosis was established. Statistical analysis demonstrated that human populations in cities close in proximity to smelters show the highest incidence of disease. The results of histological, clinical, and post-mortem examination of patients shows the highest content of toxic metals, especially Cd, in livers and kidneys. Our complex investigation of a set of disorders observed in fish and human populations indicates that there is a high probability that the negative impact on human health is caused by prolonged water contamination by heavy metals. As a novel finding, this paper shows that based on the similarity of pathological processes and bioaccumulation of metals in fish and humans, examining the content of heavy metals in fish can be used to confirm etiology and evaluate the potential risk to human health by pollution of surface waters.

Comparison of leaching characteristics of heavy metals in APC residue from an MSW incinerator using various extraction methods.

PubMed

Chiang, Kung-Yuh; Tsai, Chen-Chiu; Wang, Kuen-Sheng

2009-01-01

This study investigates four extraction methods (water extraction, toxicity characteristics leaching procedure (TCLP), modified TCLP with pH control, and sequential chemical extraction (SCE)), each representing different liquid-to-solid (L/S) ratios, pH controls, and types of leachant, and their effects on the leaching concentration of heavy metals in municipal solid waste (MSW) incinerator air pollution control (APC) residue. The results indicated that for extraction with distilled water, the heavy metal leaching concentration (mg/l) decreased with L/S ratio, but the amount of heavy metal released (AHMR), defined as the leached amount of heavy metals to the weight of the tested sample (mg/kg), increased with an increase in L/S ratio, in the range of 2-100. The results also showed that both the leaching concentration and the amount of released metals were strongly pH-dependent in the TCLP and modified TCLP tests. In the case of pHs lower than 6.5, the leaching concentrations of Cd, Pb, Cu, Zn, and Cr decreased with an increase in pH. As pH increased higher than 6.5, Cr and Zn were almost insoluble. Meanwhile, Cd and Cu also showed a similar trend but at pHs of 8.5 and 7.5, respectively. Due to the nature of amphoteric elements, in the case of pHs higher than 7, the Pb leaching concentration increased with increasing pH. In modified TCLP tests with the pH value controlled at the same level as in the SCE test, the heavy metal speciation approached the extractable carbonate bound fraction by the SCE. Both amounts of targeted metals leached from the SCE and modified TCLP tests were much higher than those for the regular TCLP and water extraction tests.

Heavy metal contamination and risk assessment in water, paddy soil, and rice around an electroplating plant.

PubMed

Liu, Jie; Zhang, Xue-Hong; Tran, Henry; Wang, Dun-Qiu; Zhu, Yi-Nian

2011-11-01

The objective of this paper is to assess the impact of long-term electroplating industrial activities on heavy metal contamination in agricultural soils and potential health risks for local residents. Water, soil, and rice samples were collected from sites upstream (control) and downstream of the electroplating wastewater outlet. The concentrations of heavy metals were determined by an atomic absorption spectrophotometer. Fractionation and risk assessment code (RAC) were used to evaluate the environmental risks of heavy metals in soils. The health risk index (HRI) and hazard index (HI) were calculated to assess potential health risks to local populations through rice consumption. Hazardous levels of Cu, Cr, and Ni were observed in water and paddy soils at sites near the plant. According to the RAC analysis, the soils showed a high risk for Ni and a medium risk for Cu and Cr at certain sites. The rice samples were primarily contaminated with Ni, followed by Cr and Cu. HRI values >1 were not found for any heavy metal. However, HI values for adults and children were 2.075 and 1.808, respectively. Water, paddy soil, and rice from the studied area have been contaminated by Cu, Cr, and Ni. The contamination of these elements is related to the electroplating wastewater. Although no single metal poses health risks for local residents through rice consumption, the combination of several metals may threaten the health of local residents. Cu and Ni are the key components contributing to the potential health risks.

RADIATION DOSE DUE TO RADON AND HEAVY METAL ANALYSIS IN DRINKING WATER SAMPLES OF JAMMU DISTRICT, JAMMU & KASHMIR, INDIA.

PubMed

Kumar, A; Kaur, M; Sharma, S; Mehra, R; Sharma, D K; Mishra, R

2016-10-01

In the present investigation, radon concentration and heavy metal analysis were carried out in drinking water samples in Jammu district, Jammu & Kashmir, India. The radon concentration was measured by using RAD-7, portable alpha particle detector. The values of radon concentration in drinking water samples were also compared within the safe limit recommended by different health agencies. The total annual effective dose ranged from 53.04 to 197.29 µSv y -1 The annual effective dose from few locations from the studied area was found to be greater than the safe limit (100 µSv y -1 ) suggested by World Health Organisation (WHO) and EU Council. Heavy metal concentration was determined by atomic absorption spectrophotometer. A total of eight elements were analysed, viz. arsenic, mercury, zinc, iron, copper, chromium, manganese and cadmium. Heavy metals are considered to be the major pollutants of water sources. The results were compared with the limits of WHO, EU and Indian organisations. The trace metal analysis is not on the exceeding side of the permissible limit in all the samples. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Element 74, the Wolfram Versus Tungsten Controversy

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

Holden,N.E.

Two and a quarter centuries ago, a heavy mineral ore was found which was thought to contain a new chemical element called heavy stone (or tungsten in Swedish). A few years later, the metal was separated from its oxide and the new element (Z=74) was called wolfram. Over the years since that time, both the names wolfram and tungsten were attached to this element in various countries. Sixty years ago, IUPAC chose wolfram as the official name for the element. A few years later, under pressure from the press in the USA, the alternative name tungsten was also allowed bymore » IUPAC. Now the original, official name 'wolfram' has been deleted by IUPAC as one of the two alternate names for the element. The history of this controversy is described here.« less

Source of atmospheric heavy metals in winter in Foshan, China.

PubMed

Tan, Ji-Hua; Duan, Jing-Chun; Ma, Yong-Liang; Yang, Fu-Mo; Cheng, Yuan; He, Ke-Bin; Yu, Yong-Chang; Wang, Jie-Wen

2014-09-15

Foshan is a ceramics manufacturing center in the world and the most polluted city in the Pearl River Delta (PRD) in southern China measured by the levels of atmospheric heavy metals. PM2.5 samples were collected in Foshan in winter 2008. Among the 22 elements and ions analyzed, 7 heavy metals (Zn, V, Mn, Cu, As, Cd and Pb) were studied in depth for their levels, spatiotemporal variations and sources. The ambient concentrations of the heavy metals were much higher than the reported average concentrations in China. The levels of Pb (675.7 ± 378.5 ng/m(3)), As (76.6 ± 49.1 ng/m(3)) and Cd (42.6 ± 45.2 ng/m(3)) exceeded the reference values of NAAQS (GB3095-2012) and the health guidelines of the World Health Organization. Generally, the levels of atmospheric heavy metals showed spatial distribution as: downtown site (CC, Chancheng District)>urban sites (NH and SD, Nanhai and Shunde Districts)>rural site (SS, Shanshui District). Two sources of heavy metals, the ceramic and aluminum industries, were identified during the sampling period. The large number of ceramic manufactures was responsible for the high levels of atmospheric Zn, Pb and As in Chancheng District. Transport from an aluminum industry park under light north-west winds contributed high levels of Cd to the SS site (Shanshui District). The average concentration of Cd under north-west wind was 220 ng/m(3), 20.5 times higher than those under other wind directions. The high daily maximum enrichment factors (EFs) of Cd, Pb, Zn, As and Cu at all four sites indicated extremely high contamination by local emissions. Back trajectory analysis showed that the heavy metals were also closely associated with the pathway of air mass. A positive matrix factorization (PMF) method was applied to determine the source apportionment of these heavy metals. Five factors (industry including the ceramic industry and coal combustion, vehicle emissions, dust, transportation and sea salt) were identified and industry was the most important source of atmospheric heavy metals. The present paper suggests a control policy on the four heavy metals Cd, Pb, Zn, and Cu, and suggests the inclusion of As in the ceramic industry emission standard in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

[Heavy metals: soil characteristics and methods of evaluating parameters for defining "contaminated soils"].

PubMed

Gagliano-Candela, R; Cammarota, R

2000-01-01

The excessive content of toxic elements in the human environment is associated with the etiology of a number of diseases. Soils' pollutants decontamination regards the main industrialised countries. Heavy metals represent the main problem for soil pollution characterisation. The first approach for pollution evaluation is the determination of total metal concentration; the evaluation of their bioavailability is required for a correct knowledge of the environmental risk. In the present work is shown the procedure to evaluate the sites, which require decontamination and which need the following data: knowledge of the threshold for each metal in the soil and its range, chemical analysis of the components, determination of bioavailability and soil destination. The bioavailability is easily calculated by the procedure of aimed extractions.

Heavy Metal Stress and Some Mechanisms of Plant Defense Response

PubMed Central

Emamverdian, Abolghassem; Ding, Yulong; Mokhberdoran, Farzad; Xie, Yinfeng

2015-01-01

Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants. PMID:25688377

Multi-elements determination in medical and edible Alpinia oxyphylla and Morinda officinalis and their decoctions by ICP-MS.

PubMed

Zhao, Xiangsheng; Wei, Jianhe; Shu, Xiaoyan; Kong, Weijun; Yang, Meihua

2016-12-01

Contents of twenty elements (Mg, K, Ca, Na, Fe, Al, Zn, Ba, Mn, Cu, Mo, Cr, Ni, As, Se, Cd, Hg, Tl, Pb and V) in two medical and edible plant species, Alpinia oxyphylla and Morinda officinalis were simultaneously determined by inductively coupled plasma-mass spectrometry (ICP-MS) method after microwave digestion with HNO 3 -H 2 O 2 (6:1, v/v) as the digestion solvent. Certified standard reference material Poplar leaf was used to assess the accuracy of the method. The greatest contents of Mg, K, Ca, Al, Fe and Na were found in dried Alpinia oxyphylla and Morinda officinalis samples. The contents of five heavy metals including Pb, Cd, As, Hg and Cu in Alpinia oxyphylla did not exceed the limits. The contents of Pb in 76.67% samples and Cd in two batches of Morinda officinalis samples exceeded the limits set by Chinese Pharmacopeia. The contents of the selected elements in different parts (leaves, stems, roots and fruits) of Alpinia oxyphylla varied considerably. The highest concentrations of Mg, Ca, Mn and Se were found in the leaves of Alpinia oxyphylla, at the same time, while, the contents of 9 elements including Cd, Cr, Cu, As, Pb in the roots were the highest. The transfer ratios of selected elements from both species of herbs into their decoctions were reduced. Especially for the heavy metals, the transfer ratios were below 30% except As (79.73%) in Morinda officinalis. The results showed that decoction of the samples may reduce the intake of heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaporation as the transport mechanism of metals in arid regions.

PubMed

Lima, Ana T; Safar, Zeinab; Loch, J P Gustav

2014-09-01

Soils of arid regions are exposed to drought and drastic temperature oscillations throughout the year. Transport mechanisms in these soils are therefore very different from the ones in temperate regions, where rain dictates the fate of most elements in soils. Due to the low rainfall and high evaporation rates in arid regions, groundwater quality is not threatened and all soil contamination issues tend to be overlooked. But if soil contamination happens, where do contaminants go? This study tests the hypothesis of upward metal movement in soils when evaporation is the main transport mechanism. Laboratory evaporation tests were carried out with heavy metal spiked Saudi soil, using circulation of air as the driving force (Fig. 1). Main results show that loamy soil retains heavy metals quite well while evaporation drives heavy metals to the surface of a sandy soil. Evaporation transports heavy metals upward in sandy soils of arid regions, making them accumulate at the soil surface. Sand being the dominating type of soil in arid regions, soils can then be a potential source of contaminated aerosols and atmospheric pollution - a transboundary problem. Some other repercussions for this problem are foreseen, such as the public ingestion or inhalation of dust. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mineralogical characteristics of sediments and heavy metal mobilization along a river watershed affected by acid mine drainage.

PubMed

Xie, Yingying; Lu, Guining; Yang, Chengfang; Qu, Lu; Chen, Meiqin; Guo, Chuling; Dang, Zhi

2018-01-01

Trace-element concentrations in acid mine drainage (AMD) are primarily controlled by the mineralogy at the sediment-water interface. Results are presented for a combined geochemical and mineralogical survey of Dabaoshan Mine, South China. Developed sequential extraction experiments with the analysis of the main mineralogical phases by semi-quantitative XRD, differential X-ray diffraction (DXRD) and scanning electron microscopy (SEM) were conducted to identify the quantitative relationship between iron minerals and heavy metals. Results showed that schwertmannite, jarosite, goethite and ferrihydrite were the dominant Fe-oxyhydroxide minerals which were detected alternately in the surface sediment with the increasing pH from 2.50 to 6.93 along the Hengshi River. Decreasing contents of schwertmannite ranging from 35 wt % to 6.5 wt % were detected along the Hengshi River, which was corresponding to the decreasing metal contents. The easily reducible fractions exert higher affinity of metals while compared with reducible and relatively stable minerals. A qualitative analysis of heavy metals extracted from the sediments indicated that the retention ability varied: Pb > Mn > Zn > As ≈ Cu > Cr > Cd ≈ Ni. Results in this study are avail for understanding the fate and transport of heavy metals associated with iron minerals and establishing the remediation strategies of AMD systems.

Mineralogical characteristics of sediments and heavy metal mobilization along a river watershed affected by acid mine drainage

PubMed Central

Xie, Yingying; Yang, Chengfang; Qu, Lu; Chen, Meiqin; Guo, Chuling; Dang, Zhi

2018-01-01

Trace-element concentrations in acid mine drainage (AMD) are primarily controlled by the mineralogy at the sediment-water interface. Results are presented for a combined geochemical and mineralogical survey of Dabaoshan Mine, South China. Developed sequential extraction experiments with the analysis of the main mineralogical phases by semi-quantitative XRD, differential X-ray diffraction (DXRD) and scanning electron microscopy (SEM) were conducted to identify the quantitative relationship between iron minerals and heavy metals. Results showed that schwertmannite, jarosite, goethite and ferrihydrite were the dominant Fe-oxyhydroxide minerals which were detected alternately in the surface sediment with the increasing pH from 2.50 to 6.93 along the Hengshi River. Decreasing contents of schwertmannite ranging from 35 wt % to 6.5 wt % were detected along the Hengshi River, which was corresponding to the decreasing metal contents. The easily reducible fractions exert higher affinity of metals while compared with reducible and relatively stable minerals. A qualitative analysis of heavy metals extracted from the sediments indicated that the retention ability varied: Pb > Mn > Zn > As ≈ Cu > Cr > Cd ≈ Ni. Results in this study are avail for understanding the fate and transport of heavy metals associated with iron minerals and establishing the remediation strategies of AMD systems. PMID:29304091

First survey of atmospheric heavy metal deposition in Kosovo using moss biomonitoring.

PubMed

Maxhuni, Albert; Lazo, Pranvera; Kane, Sonila; Qarri, Flora; Marku, Elda; Harmens, Harry

2016-01-01

Bryophytes act as bioindicators and bioaccumulators of metal deposition in the environment. The atmospheric deposition of Cd, Cr, Cu, Fe, Hg, Ni, Mn, Pb, and Zn in Kosovo was investigated by using carpet-forming moss species (Pseudocleropodium purum and Hypnum cupressiforme) as bioindicators. This research is part of the European moss survey coordinated by the ICP Vegetation, an International Cooperative Programme reporting on the effects of air pollution on vegetation to the UNECE Convention on Long-range Transboundary Air Pollution. Sampling was performed during the summer of 2011 at 25 sampling sites homogenously distributed over Kosovo. Unwashed, dried samples were digested by using wet digestion in Teflon tubes. The concentrations of metal elements were determined by atomic absorption spectrometry (AAS) equipped with flame and/or furnace systems. The heavy metal concentration in mosses reflected local emission sources. The data obtained in this study were compared with those of similar studies in neighboring countries and Europe (2010-2014 survey). The geographical distribution maps of the elements over the sampled territory were constructed using geographic information system (GIS) technology. The concentrations of Cr, Ni, Pb, and Zn were higher than the respective median values of Europe, suggesting that the zones with heavy vehicular traffic and industry emission input are important emitters of these elements. Selected zones are highly polluted particularly by Cd, Pb, Hg, and Ni. The statistical analyses revealed that a strong correlation exists between the Pb and Cd content in mosses, and the degree of pollution in the studied sites was assessed.

Heavy metal pollution and forest health in the Ukrainian Carpathians.

PubMed

Shparyk, Y S; Parpan, V I

2004-07-01

The Ukrainian Carpathians are characterized by high air pollution caused by emissions from numerous industries. We have been monitoring the state of forests in this region since 1989. The highest levels of tree defoliation (>30%) are found close to industrial emission sources and in the upper mountain forests of the Ivano-Frankivsk and Chernivtsi regions. This is caused by a combination of strong anthropogenic influences (pollution, illegal uses, recreation) as well as poor site and climatic conditions. In the Ivano-Frankivsk region, Cd and Mo accumulate in forest soils; Cr, Mo and Zn soil concentrations are higher than their limit levels; and Pb concentrations exceed toxic levels close to industrial areas (10% of the region territory). Local background levels of heavy metals are greatly exceeded in snow close to industrial regions. Analysis of correlation matrices shows that the chemical elements Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn occur at pollution levels in natural ecosystems in the Ukrainian Carpathians. Maximum concentrations of toxic elements occur in the oak forest zone; the most industrially developed area of the region. Toxic heavy metals in the Ukrainian Carpathians forests enter with precipitation and dustfall, then become fixed in soil and accumulate in leaves, needles of vascular plants and mosses. Concentrations of these metals decrease with altitude: highest in the oak forests, less in beech, and lowest in the spruce forest zones. However, some chemical elements have the highest concentrations in spruce forests; V in needles, As in snow, and Ba and Al in soils.

Toxic heavy metals in human blood in relation to certain food and environmental samples in Kerala, South India.

PubMed

Jose, Anitha; Ray, Joseph George

2018-03-01

Toxic heavy metals such as arsenic (As), lead (Pb), and mercury (Hg) are systemic toxicants that are hazardous to human health. However, as these elements are increasing in the environment due to fast urbanization, industrialization, and chemicalized agricultural activities, accumulation of the same in human body anywhere in the world is quite interesting to global assessment of environment quality. In this connection, random examination of blood samples of human population in Kerala, South India, was carried out to assess the threat of heavy metal contamination to humans in this part of the globe, especially in relation to the amount of such metals in food and other environmental samples. Except pure vegetarians, people of Kerala consume rice as the staple food with a lot of fish. Therefore, the amount of these three heavy metals in drinking water, fish, rice, and paddy soils was done. Heavy metals in the blood were examined in relation to age, gender, and dietary habits such as frequency of fish eating or vegetarianism. Influence of dental amalgam fillings on blood mercury levels was also analyzed. Quantitative assessment of metals in samples was done by inductively coupled plasma-mass spectrometry (ICP-MS). The levels of arsenic, lead, and mercury were found well below the reference values, though diet seemed to pull them up as the amount of metals in blood showed significant differences between vegetarians and non-vegetarians. Evidence to the influence of dental amalgam fillings on blood mercury levels could not be established with the present samples.

Examining Two Sets of Introgression Lines in Rice (Oryza sativa L.) Reveals Favorable Alleles that Improve Grain Zn and Fe Concentrations

PubMed Central

Hu, Xia; Cheng, Li-Rui; Xu, Jian-Long; Shi, Yu-Min; Li, Zhi-Kang

2015-01-01

In the modern world, the grain mineral concentration (GMC) in rice (Oryza sativa L.) not only includes important micronutrient elements such as iron (Fe) and zinc (Zn), but it also includes toxic heavy metal elements, especially cadmium (Cd) and lead (Pb). To date, the genetic mechanisms underlying the regulation of GMC, especially the genetic background and G × E effects of GMC, remain largely unknown. In this study, we adopted two sets of backcross introgression lines (BILs) derived from IR75862 (a Zn-dense rice variety) as the donor parent and two elite indica varieties, Ce258 and Zhongguangxiang1, as recurrent parents to detect QTL affecting GMC traits including Fe, Zn, Cd and Pb concentrations in two environments. We detected a total of 22 loci responsible for GMC traits, which are distributed on all 12 rice chromosomes except 5, 9 and 10. Six genetic overlap (GO) regions affecting multiple elements were found, in which most donor alleles had synergistic effects on GMC. Some toxic heavy metal-independent loci (such as qFe1, qFe2 and qZn12) and some regions that have opposite genetic effects on micronutrient (Fe and Zn) and heavy metal element (Pb) concentrations (such as GO-IV) may be useful for marker-assisted biofortification breeding in rice. We discuss three important points affecting biofortification breeding efforts in rice, including correlations between different GMC traits, the genetic background effect and the G × E effect. PMID:26161553

Atmospheric inorganic trace contaminants in Finland, especially in the Gulf of Finland area

NASA Astrophysics Data System (ADS)

Jalkanen, Liisa Maria

Atmospheric aerosol samples were collected at Utö and Virolahti in the Gulf of Finland area and Ähtäri in Central Finland using a filter pack. The samples were analysed by instrumental neutron activation analysis (INAA) and inductively coupled plasma mass-spectrometry (ICP-MS) for 34 elements including halogens and heavy metals. A very simple and quantitative acid digestion method was developed for the dissolution of the aerosol samples for ICP-MS analysis. Analysis of the elemental data is given using trajectories, principal component analysis and long-range transport modelling. The average total (fine + coarse) atmospheric concentrations range at Utö from 0.083 ng m -3 for Cd to 730 ng m-3 for Na. The sea areas (Utö, Virolahti, Hailuoto) have most of the heavy metal air pollution in Finland, as witnessed by the aerosol concentration and wet deposition data. There is a clear decreasing gradient in the deposition of As, Cd, Cr, Pb, and V from South to North in Finland. In general, the trace element concentrations and deposition are lower in Finland than in Central Europe. The effect of large particulate emission sources in Estonia can be seen in the elemental concentrations of atmospheric particles and in the deposition around the eastern Gulf of Finland region. There has been a remarkable decrease in heavy metal emissions in Finland during the 1990s. However, due to long-range transport, the decrease in deposition as witnessed by analysis of these concentrations in precipitation and moss is much less than would be expected.

[Distribution of chemical elements in whole blood and plasma].

PubMed

Barashkov, G K; Zaĭtseva, L I; Kondakhchan, M A; Konstantinova, E A

2003-01-01

The distribution factor (Fd) of 35 elements of plasma and whole blood in 26 healthy men and women was detected by ICP-OES. Usilig this parameter the elements were subdivided in 3 pools. 9 of them have Fd higher than 1.5 ("elements of plasma"-Ag, Ca, Cu, In, Li, Na, Se, Si, Sr); 6 have lower than 0.5 ("elements of blood cells"-Fe, K, Mn, Ni, V, Zn), other 20-about 1 ("blood elements"). Fd of all elements depends on ionic radius. Elements of 2nd sub-groups of all groups of Mendeleev's periodic table ("heavy metals") depend on the similar law: "with growing of ionic radius the concentration of elements in plasma enhances". In alkaline metals Fd depends on the opposite law:" with growing of ionic radius of alkaline metal the quantity of elements in blood cells enhance". Dependence of Fd on the value of atomic mass in periods or in exterior electronic cloud (s-, p-, d-, f-) was not established. The table of distribution of all detected elements in whole blood in relation to 8 macroelements (Ca, Mg, K, Na, S, P, Fe, Zn,) is presented, as a basic diagnostic criteria in metal-ligand homeostasis disturbance.

Selected toxic and essential heavy metals in impacted teeth and the surrounding mandibular bones of people exposed to heavy metals in the environment.

PubMed

Malara, Piotr; Fischer, Agnieszka; Malara, Beata

2016-01-01

The elemental composition of bones and teeth can allow exposure to heavy metals in the environment to be estimated. The aim of this study was to determine whether impacted mandibular teeth and the surrounding bones can be used as biomonitoring media to assess exposure to heavy metals. The research materials were 67 impacted lower third molars and samples of the cortical bone removed when the wisdom teeth were surgically extracted. The samples were from people living in two areas with different environmental concentrations of heavy metals. The cadmium, chromium, copper, iron, lead, manganese, and zinc concentrations in the samples were determined by atomic absorption spectrometry with flame atomization. The cadmium and lead concentrations in the impacted third molars and the bones surrounding the teeth were significantly higher for people living in the relatively polluted Ruda Slaska region than for people living in Bielsko-Biala region. Significantly higher chromium, copper, manganese, and zinc concentrations were found in the bones surrounding the impacted teeth from people living in Ruda Slaska than in the bones surrounding the impacted teeth from people living in Bielsko-Biala. The cadmium concentrations in impacted teeth and the surrounding bones were significantly positively correlated. The results indicated that impacted mandibular teeth and the surrounding mandibular bones may reflect the exposure of people to cadmium and lead in the environment. This conclusion, however, must be verified in future research projects designed to exclude the possibility of additional dietary, occupational, and other types of exposure to heavy metals.

Characterization and structure prediction of partial length protein sequences of pcoA, pcoR and chrB genes from heavy metal resistant bacteria from the Klip River, South Africa.

PubMed

Chihomvu, Patience; Stegmann, Peter; Pillay, Michael

2015-04-01

The Klip River has suffered from severe anthropogenic effects from industrial activities such as mining. Long-term exposure to heavy metal pollution has led to the development of heavy metal resistant strains of Pseudomonas sp. KR23, Lysinibacillus sp. KR25, and E. coli KR29. The objectives of this study were to characterize the genetics of copper and chromate resistance of the isolates. Copper and chromate resistance determinants were cloned and sequenced. Open reading frames (ORFs) related to the genes CopA and CopR were identified in E. coli KR29, PcoA in Lysinibacillus sp. KR25 and none related to chromate resistance were detected. The 3D-models predicted by I-TASSER disclose that the PcoA proteins consist of β-sheets, which form a part of the cupredoxin domain of the CopA copper resistance family of genes. The model for PcoR_29 revealed the presence of a helix turn helix; this forms part of a DNA binding protein, which is part of a heavy metal transcriptional regulator. The bacterial strains were cured using ethidium bromide. The genes encoding for heavy metal resistance and antibiotic resistance were found to be located on the chromosome for both Pseudomonas sp. (KR23) and E. coli (KR29). For Lysinibacillus (KR25) the heavy metal resistance determinants are suspected to be located on a mobile genetic element, which was not detected using gel electrophoresis.

Characterization and Structure Prediction of Partial Length Protein Sequences of pcoA, pcoR and chrB Genes from Heavy Metal Resistant Bacteria from the Klip River, South Africa

PubMed Central

Chihomvu, Patience; Stegmann, Peter; Pillay, Michael

2015-01-01

The Klip River has suffered from severe anthropogenic effects from industrial activities such as mining. Long-term exposure to heavy metal pollution has led to the development of heavy metal resistant strains of Pseudomonas sp. KR23, Lysinibacillus sp. KR25, and E. coli KR29. The objectives of this study were to characterize the genetics of copper and chromate resistance of the isolates. Copper and chromate resistance determinants were cloned and sequenced. Open reading frames (ORFs) related to the genes CopA and CopR were identified in E. coli KR29, PcoA in Lysinibacillus sp. KR25 and none related to chromate resistance were detected. The 3D-models predicted by I-TASSER disclose that the PcoA proteins consist of β-sheets, which form a part of the cupredoxin domain of the CopA copper resistance family of genes. The model for PcoR_29 revealed the presence of a helix turn helix; this forms part of a DNA binding protein, which is part of a heavy metal transcriptional regulator. The bacterial strains were cured using ethidium bromide. The genes encoding for heavy metal resistance and antibiotic resistance were found to be located on the chromosome for both Pseudomonas sp. (KR23) and E. coli (KR29). For Lysinibacillus (KR25) the heavy metal resistance determinants are suspected to be located on a mobile genetic element, which was not detected using gel electrophoresis. PMID:25837632

Bacterial community structure and abundances of antibiotic resistance genes in heavy metals contaminated agricultural soil.

PubMed

Zhang, Fengli; Zhao, Xiaoxue; Li, Qingbo; Liu, Jia; Ding, Jizhe; Wu, Huiying; Zhao, Zongsheng; Ba, Yue; Cheng, Xuemin; Cui, Liuxin; Li, Hongping; Zhu, Jingyuan

2018-04-01

Soil contamination with heavy metals is a worldwide problem especially in China. The interrelation of soil bacterial community structure, antibiotic resistance genes, and heavy metal contamination in soil is still unclear. Here, seven agricultural areas (G1-G7) with heavy metal contamination were sampled with different distances (741 to 2556 m) to the factory. Denaturing gradient gel electrophoresis (DGGE) and Shannon index were used to analyze bacterial community diversity. Real-time fluorescence quantitative PCR was used to detect the relative abundance of ARGs sul1, sul2, tetA, tetM, tetW, one mobile genetic elements (MGE) inti1. Results showed that all samples were polluted by Cadmium (Cd), and some of them were polluted by lead (Pb), mercury (Hg), arsenic (As), copper (Cu), and zinc (Zn). DGGE showed that the most abundant bacterial species were found in G7 with the lightest heavy metal contamination. The results of the principal component analysis and clustering analysis both showed that G7 could not be classified with other samples. The relative abundance of sul1 was correlated with Cu, Zn concentration. Gene sul2 are positively related with total phosphorus, and tetM was associated with organic matter. Total gene abundances and relative abundance of inti1 both correlated with organic matter. Redundancy analysis showed that Zn and sul2 were significantly related with bacterial community structure. Together, our results indicate a complex linkage between soil heavy metal concentration, bacterial community composition, and some global disseminated ARG abundance.

Chemical evolution with rotating massive star yields - I. The solar neighbourhood and the s-process elements

NASA Astrophysics Data System (ADS)

Prantzos, N.; Abia, C.; Limongi, M.; Chieffi, A.; Cristallo, S.

2018-05-01

We present a comprehensive study of the abundance evolution of the elements from H to U in the Milky Way halo and local disc. We use a consistent chemical evolution model, metallicity-dependent isotopic yields from low and intermediate mass stars and yields from massive stars which include, for the first time, the combined effect of metallicity, mass loss, and rotation for a large grid of stellar masses and for all stages of stellar evolution. The yields of massive stars are weighted by a metallicity-dependent function of the rotational velocities, constrained by observations as to obtain a primary-like 14N behaviour at low metallicity and to avoid overproduction of s-elements at intermediate metallicities. We show that the Solar system isotopic composition can be reproduced to better than a factor of 2 for isotopes up to the Fe-peak, and at the 10 per cent level for most pure s-isotopes, both light ones (resulting from the weak s-process in rotating massive stars) and the heavy ones (resulting from the main s-process in low and intermediate mass stars). We conclude that the light element primary process (LEPP), invoked to explain the apparent abundance deficiency of the s-elements with A < 100, is not necessary. We also reproduce the evolution of the heavy to light s-elements abundance ratio ([hs/ls]) - recently observed in unevolved thin disc stars - as a result of the contribution of rotating massive stars at sub-solar metallicities. We find that those stars produce primary F and dominate its solar abundance and we confirm their role in the observed primary behaviour of N. In contrast, we show that their action is insufficient to explain the small observed values of ^{12}C/^{13}C in halo red giants, which is rather due to internal processes in those stars.

Surveys of research in the Chemistry Division, Argonne National Laboratory

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

Grazis, B.M.

1992-01-01

Research reports are presented on reactive intermediates in condensed phase (radiation chemistry, photochemistry), electron transfer and energy conversion, photosynthesis and solar energy conversion, metal cluster chemistry, chemical dynamics in gas phase, photoionization-photoelectrons, characterization and reactivity of coal and coal macerals, premium coal sample program, chemical separations, heavy elements coordination chemistry, heavy elements photophysics/photochemistry, f-electron interactions, radiation chemistry of high-level wastes (gas generation in waste tanks), ultrafast molecular electronic devices, and nuclear medicine. Separate abstracts have been prepared. Accelerator activites and computer system/network services are also reported.

Surveys of research in the Chemistry Division, Argonne National Laboratory

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

Grazis, B.M.

1992-11-01

Research reports are presented on reactive intermediates in condensed phase (radiation chemistry, photochemistry), electron transfer and energy conversion, photosynthesis and solar energy conversion, metal cluster chemistry, chemical dynamics in gas phase, photoionization-photoelectrons, characterization and reactivity of coal and coal macerals, premium coal sample program, chemical separations, heavy elements coordination chemistry, heavy elements photophysics/photochemistry, f-electron interactions, radiation chemistry of high-level wastes (gas generation in waste tanks), ultrafast molecular electronic devices, and nuclear medicine. Separate abstracts have been prepared. Accelerator activites and computer system/network services are also reported.

Spatial variability in depth and landscape of heavy metal contents of volcanic soils of the National Cajas Park in the Azuay Andes (Ecuador)

NASA Astrophysics Data System (ADS)

Bech, Jaume; Roca, Núria; Boluda, Rafael; Gil, Carlos; Ramos-Miras, Joaquín; Rodríguez, Jose A.

2015-04-01

Although the soils in the Azuay Andes are thought to be generally non-contaminated, it is necessary to preserve them from anthropogenic pollution. This area supplies drinking water to Cuenca, the third city of Ecuador. At present, very little information is available on baseline metal concentrations in Latin American soils. Therefore, it is important to establish the baseline of elements in soils as reference values for evaluating potential changes in their concentrations and to be able to define their origins. The objectives of this study are: (1) to show morphological, physical and chemical characteristics of Andisols in the Azuay Andes (Ecuador); (2) to determine the concentrations of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and (3) to evaluate the relationship between metal concentration and soil properties. The study area is located in National Cajas Park in the Paramo area of the Andes at Azuay Province (Ecuador). The geological origin of the National Cajas Park dates back to the Quaternary age. This area is a U-shaped glaciated valley formed over a pre-existing volcanic basement which consists of rhyolite and andesite volcanic tuff. The moraines are covered by discontinuous patches of volcanic ash. The climate is characterized by rather high rainfall, between 1200 to 2000 mm per year, regularly distributed and generally of a low intensity with a yearly average constant temperature (7°C) with high diurnal amplitudes. The paramo is a high altitude neotropical grassland ecosystem, located between the continuous forest border (~3500 m) and the eternal snow line (~5000 m). Seven representative volcanic soil pedons of a toposequence were studied and sampled. All horizons were analysed for physical and chemical properties by standard and specific methods for volcanic soils. Total metal concentrations in soil horizons were determined by ICP-MS spectrometer. The background values were calculated using the 4σ-outlier test. This requires the elimination of potential outliers from the data set and the calculation of the mean and the standard deviation for the remaining sub-collective. Andisols are dominated by amorphous aluminium silicates and Al-organic complexes. The soils of a volcanic area usually have an Ah-Bh-Bhs/ Bw-C horizon sequence. The Ah horizon is dark-coloured and very high in organic carbon. The pH NaF usually rises to 10.5 below 20 cm. Correlation metal concentration with pH NaF may reflect the impact of volcanic pedogenetic pathways of soils on the original trace elements distribution (Cr and Pb). Close relationships between organic matter have a marked affinity to trace elements (Cd and Cu) forming organomineral complexes. Ni and Zn present a close relationship with soil grain distribution. This may reflect the impact of wind or water on the original parent material distribution. The great dispersion of heavy metals between horizons could be horizon discontinuities. The elements Zr, Ti and Y, have been widely used as indices of immobile minerals. These studies must be performed to definitively confirm the complex profiles. Cadmium, Cu, Ni and Zn showed highly significant differences between Andisols. The complex association of the soils in the landscape was attributed to the difference in their parent material compositions. Occasional or continuous addition of volcanic deposits to soil becomes the soil forming process, and is decisive in the distribution of heavy metals. Although, the Azuay soils have shown a spatial variability of heavy metal concentrations in depth and landscape, the data sets were predominantly influenced by natural element distribution. In general, the upper limits of heavy metal background are (in mg•kg-1): Cd (1), Cr (44), Cu (54), Ni (10), Pb (69) and Zn (149). Only one point with slight enrichment Cd anomalies were observed: A4 (35-69 cm): 1.72 mg•kg-1. The concentrations of heavy metals found in the Cajas National Park are normal and do not show any sign of contamination. Acknowledgements The authors are grateful to L. Tonon, G. Larriva of the University of Cuenca (Ecuador) and S. Ugalde for their technical support in this study.

Evaluation of Heavy Metal Exposure to Soil and Paddy Plant around the Closed Municipal Solid Waste Landfill: Case Study at Gunung Tugel Landfill, Banyumas-Central Java

NASA Astrophysics Data System (ADS)

Kasam; Rahmawati, Suphia; Mulya Iresha, Fajri; Wacano, Dhandhun; Farida Fauziah, Ida; Afif Amrullah, Muhammad

2018-01-01

This work was focused on assessing the exposure of heavy metal from closed municipal solid waste (MSW) landfill on soil and paddy plants. This study aimed to determine heavy metal content whether at the soil in the around Gunung Tugel landfill included and accumulated in the paddy plant tissues. The investigated metals include chromium (Cr), copper (Cu), cadmium (Cd), iron (Fe), and zinc (Zn). The samples were acid-digested before the desired elements were measured using Atomic Absorption Spectrophotometry (AAS). The results are presented as distribution map of the landfill area based on the total heavy metals content distribution in the soil and paddy plants. The samples shown that the concentrations of heavy metals around Gunung Tugel landfill are 6.27-34.71 mg/kg, 0.17-0.42 mg/kg, 28.29-48.69 mg/kg, 18,997.26-32,572.29 mg/kg, 342.74-834.49 mg/kg, 136.10-290.14 mg/kg at the top soil and 0.00-1.70 mg/kg, 0.00-0.26 mg/kg, 0.79-10.46 mg/kg, 13.88-61.46 mg/kg, 18.79-50.56 mg/kg, 87.27-273.22 mg/kg at the paddy for Cr, Cd, Cu, Fe, Mn, and Zn respectively. According to the results, The Gunung Tugel landfill is not a direct source of heavy metal pollution at paddy plant in the landfill area, but through surface water and soil media. Rainfall around landfill is quite high ie more 2000 mm/year of rainfall and soil permeability is 1.0 cm/sec.

[Speciation Distribution and Risk Assessment of Heavy Metals in Typical Material Roof Dusts].

PubMed

Li, Dun-zhu; Guan, Yun-tao; Liu, An; Li, Si-yuan

2015-09-01

With the modified BCR sequential extraction procedure, the chemical speciation and risk for 10 heavy metals (Ba, Co, Cr, Cu, Mn, Ni, Pb, Sb, Sr and Zn) in roof dusts were investigated. The subjects of this study were collected from four typical material paved roofs (i. e., ceramic tile, concrete, metal and asphalt) in southeast China. The results indicated that the average contents of heavy metals in roof dust significantly exceeded road dust. The analysis of chemical fraction showed that the acid soluble/exchangeable fraction of Zn was much higher than other elements, the existence of Pb and Cu was mainly in oxidization fraction, while other heavy metals dominated by the residual fraction. The mobility sequence percentages for all roof dust samples decreased in the order of Pb > Zn > Cu >Mn > Co >Sr > Sb > Ni > Ba > Cr, and it should be noted that Pb, Zn, Cu, Mn and Co all have more than 50% proportion in mobility sequence. Based on environmental risk assessment, the highest values of contamination factors (Cf) and risk assessment code (RAC) consistently was observed in Zn, which indicated that Zn had relatively high ecological risk. Health risk assessment showed that the non-carcinogenic hazard indexes (HI) of heavy metals decreased in the order of Pb > Cr > Sb > Zn > Mn > Cu > Ba > Ni > Co > Sr, the HI of heavy metals for adults were lower than safe value while the HI of Pb for children was higher than safe value, suggesting that they will not harm the adult's health except Pb for children. The carcinogenic risk for Cr, Co and Ni were all below the threshold values, which indicated that there was no carcinogenic risk.

Heavy Metal Pollution of Lakes along the Mid-Lower Reaches of the Yangtze River in China: Intensity, Sources and Spatial Patterns

PubMed Central

Zeng, Haiao; Wu, Jinglu

2013-01-01

Lakes in the middle and lower reaches of the Yangtze River form a shallow lake group unique in the World that is becoming increasingly polluted by heavy metals. Previous studies have largely focused on individual lakes, with limited exploration of the regional pattern of heavy metal pollution of the lake group in this area. This paper explores the sources, intensity and spatial patterns of heavy metal pollution of lake sediments. A total of 45 sample lakes were selected and the concentrations of key metal elements in the sediments of each lake were measured. The cluster analysis (CA), principal component analysis (PCA) and Geo-accumulation index (Ig) analysis permitted analysis of the source and pollution intensity of the target lakes. Results suggested a notable spatial variation amongst the sample lakes. Lakes in the upper part of the lower reach of the Yangtze River surrounded by typical urban landscapes were strongly or extremely polluted, with high concentrations of Pb, Zn, Cu and Cd in their sediments. This was attributed to large amount of untreated industrial discharges and municipal sewage produced within the lake catchments. In contrast, the heavy-metal pollution of lakes in the Taihu Delta area was notably lower due to industrial restructuring and implementation of effective environmental protection measures. Lakes along the middle reach of Yangtze River surrounded by agricultural areas were unpolluted to moderately polluted by heavy metals overall. Our results suggested that lakes in the central part of China require immediate attention and efforts should be made to implement management plans to prevent further degradation of water quality in these lakes. PMID:23442559

Heavy Metals Toxicity and the Environment

PubMed Central

Tchounwou, Paul B; Yedjou, Clement G; Patlolla, Anita K; Sutton, Dwayne J

2013-01-01

Heavy metals are naturally occurring elements that have a high atomic weight and a density at least 5 times greater than that of water. Their multiple industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment; raising concerns over their potential effects on human health and the environment. Their toxicity depends on several factors including the dose, route of exposure, and chemical species, as well as the age, gender, genetics, and nutritional status of exposed individuals. Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and mercury rank among the priority metals that are of public health significance. These metallic elements are considered systemic toxicants that are known to induce multiple organ damage, even at lower levels of exposure. They are also classified as human carcinogens (known or probable) according to the U.S. Environmental Protection Agency, and the International Agency for Research on Cancer. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, genotoxicity, and carcinogenicity. PMID:22945569

Impact of WWII dumpsites on Saipan (CNMI): heavy metal status of soils and sediments.

PubMed

Denton, Gary R W; Emborski, Carmen A; Hachero, April A B; Masga, Ray S; Starmer, John A

2016-06-01

A number of dumpsites occur on the island of Saipan and in the surrounding coastal waters. Many of these sites date back to the immediate post WWII clean-up period and contain a variety of wartime wastes. Metallic debris is generally the most visible waste material and commonly includes bomb fragments, artillery shells, bullets, and other military hardware. In this investigation, we examined the heavy metal status of soils from around several of these dumpsites and in any obvious drainage pathways leading from them to the coast. Sediments were also taken for analysis from a number of coastal discharge points and three submerged sites. Metal enrichment was evident for one or more elements in deposits from two of the three submerged sites and 24 of the 32 land-based sites visited. Copper, Pb, and Zn were the most commonly encountered contaminant metals with levels well in excess of 1000 μg/g(-1) in several instances. Elevated Hg and Cd concentrations were also relatively widespread throughout the study area although levels of each element seldom exceeded 1.0 and 10.0 μg/g(-1), respectively. Silver, another element of toxicological concern, was only occasionally detected despite registering a high of 42 μg/g(-1) at one particular site. The metal data were weighed against established benchmarks formulated for the protection of human and ecological health. Implications of the findings and issues of primary concern are briefly addressed.

Human Health Risks Associated with Metals from Urban Soil and Road Dust in an Oilfield Area of Southeastern Algeria.

PubMed

Benhaddya, Mohammed Lamine; Boukhelkhal, Abdelaziz; Halis, Youcef; Hadjel, Mohammed

2016-04-01

Hassi Messaoud town is a recent city that is situated inside the oil field, which hosts an important petroleum extraction field and refinery. Large-scale and long-term oil refinery and corresponding industrial activities may contaminate the surrounding soil/dust and could lead to pollution levels that can affect human health. The soil and road dust samples were analysed for different trace elements: copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). Geo-accumulation index (I(geo)), pollution index (PI), and integrated pollution index (IPI) were calculated to evaluate the heavy metal contamination level of urban soil and road dust. The I(geo) values indicate unpolluted to moderate polluted of investigated metals in the soil samples. The assessment results of PI support the results of I(geo), and IPI indicates heavy metals in road dust polluted seriously. The noncarcinogenic health risk assessment shows that ingestion of soil/dust particles is the route for exposure to heavy metals, followed by dermal adsorption. The human exposure risk assessment based on different exposure pathways showed that the hazard index (HI) was <1.0 for all of the elements. The relative exposure risk (noncarcinogenic) was greater for toddlers. Although the overall risk was within the acceptable limit of 1.00, the HI of Pb from the soil (0.103) and road dust (0.132) was close to the threshold limits, which over the long-term may pose a health risk.

Assessing soil heavy metal pollution in the water-level-fluctuation zone of the Three Gorges Reservoir, China.

PubMed

Ye, Chen; Li, Siyue; Zhang, Yulong; Zhang, Quanfa

2011-07-15

The water-level-fluctuation zone (WLFZ) between the elevations of 145-175 m in China's Three Gorges Reservoir has experienced a novel hydrological regime with half a year (May-September) exposed in summer and another half (October-April) submerged in winter. In September 2008 (before submergence) and June 2009 (after submergence), soil samples were collected in 12 sites in the WLFZ and heavy metals (Hg, As, Cr, Cd, Pb, Cu, Zn, Fe, and Mn) were determined. Enrichment factor (EF), factor analysis (FA), and factor analysis-multiple linear regression (FA-MLR) were employed for heavy metal pollution assessment, source identification, and source apportionment, respectively. Results demonstrate spatial variability in heavy metals before and after submergence and elements of As, Cd, Pb, Cu, and Zn are higher in the upper and low reaches. FA and FA-MLR reveal that As and Cd are the primary pollutants before submergence, and over 45% of As originates from domestic sewage and 59% of Cd from industrial wastes. After submergence, the major contaminants are Hg, Cd, and Pb, and traffic exhaust contributes approximately 81% to Hg and industrial effluent accounts about 36% and 73% for Cd and Pb, respectively. Our results suggest that increased shipping and industrial wastes have deposited large amounts of heavy metals which have been accumulated in the WLFZ during submergence period. Copyright © 2011 Elsevier B.V. All rights reserved.

A comprehensive analysis of heavy metals in urban road dust of Xi'an, China: Contamination, source apportionment and spatial distribution.

PubMed

Pan, Huiyun; Lu, Xinwei; Lei, Kai

2017-12-31

A detailed investigation was conducted to study heavy metal contamination in road dust from four regions of Xi'an, Northwest China. The concentrations of eight heavy metals Co, Cr, Cu, Mn, Ni, Pb, Zn and V were determined by X-Ray Fluorescence. The mean concentrations of these elements were: 30.9mgkg -1 Co, 145.0mgkg -1 Cr, 54.7mgkg -1 Cu, 510.5mgkg -1 Mn, 30.8mgkg -1 Ni, 124.5mgkg -1 Pb, 69.6mgkg -1 V and 268.6mgkg -1 Zn. There was significant enrichment of Pb, Zn, Co, Cu and Cr based on geo-accumulation index value. Multivariate statistical analysis showed that levels of Cu, Pb, Zn, Co and Cr were controlled by anthropogenic activities, while levels of Mn, Ni and V were associated with natural sources. Principle component analysis and multiple linear regression were applied to determine the source apportionment. The results showed that traffic was the main source with a percent contribution of 53.4%. Natural sources contributed 26.5%, and other anthropogenic pollution sources contributed 20.1%. Clear heavy metal pollution hotspots were identified by GIS mapping. The location of point pollution sources and prevailing wind direction were found to be important factors in the spatial distribution of heavy metals. Copyright © 2017 Elsevier B.V. All rights reserved.

Heavy metals in industrially emitted particulate matter in Ile-Ife, Nigeria.

PubMed

Ogundele, Lasun T; Owoade, Oyediran K; Hopke, Philip K; Olise, Felix S

2017-07-01

Iron and steel smelting facilities generate large quantities of airborne particulate matter (PM) through their various activities and production processes. The resulting PM that contains a variety of heavy metals has potentially detrimental impacts on human health and the environment. This study was conducted to assess the potential health effects of the pollution from the heavy metals in the airborne PM sampled in the vicinity of secondary smelting operations in Ile-Ife, Nigeria. X-ray fluorescence (XRF) was used to determine the elemental concentration of Pb, Cr, Cd, Zn, Mn, As, Fe, Cu, and Ni in the size-segregated PM samples. Pollution Indices (PI) consisting of Contamination Factor (CF), Degree of Contamination (DC) and Pollution Index Load (PLI) and Target Hazard Quotient (THQ) were employed to assess the pollution risk associated with the heavy metals in the PM. CF, DC and PLI values were 3< CF <6, >32 and >1, respectively for the three sites, indicating deterioration of the ambient air quality in the vicinity of the smelter. The heavy metals in the airborne PM pose a severe health risk to people living in vicinity of the facility and to its workers. The diminished air quality with the associated health risks directly depends on the industrial emissions from steel production and control measures are recommended to mitigate the likely risks. Copyright © 2017 Elsevier Inc. All rights reserved.

Functionalization of magnetic hollow porous oval shape NiFe2O4 as a highly selective sorbent for the simultaneous determination of five heavy metals in real samples.

PubMed

Liu, Mingyang; Yang, Lijun; Zhang, Lei

2016-12-01

In this study, a functionalized magnetic hollow porous oval-shape NiFe 2 O 4 (MHPO-NiFe 2 O 4 ) was designed by a facile synthesis procedure, and employed as magnetic solid phase extraction (MSPE) material to extract several heavy metal ions. As-prepared MHPO-NiFe 2 O 4 exhibited superior adsorption capacities of 20.17, 16.64, 16.82, 9.69 and 16.58mgg -1 , for Cu(II), Cd(II), Cr(III), Co(II) and Zn(II), and was then used to detect these heavy metals elements in real samples by combining with inductively coupled plasma optical emission spectroscopy (ICP-OES). The possible mechanism of the enrichment of heavy metals ions on MHPO-NiFe 2 O 4 was proposed, which involved the dominant adsorption and desorption. The detection limits were as low as 0.015, 0.13, 0.062, 0.035 and 0.46μgL -1 for Cu(II), Cd(II), Cr(III), Co(II) and Zn(II), respectively. A good repeatability was obtained with the relative standard deviation (RSD) of 3.87%. Moreover, the method was successfully utilized for the analysis of five heavy metals in real samples (cabbage, lettuce, apple, seawater), with satisfactory recoveries in the range of 92-108%. Copyright © 2016 Elsevier B.V. All rights reserved.

Laser-induced breakdown spectroscopic detection of trace level heavy metal in solutions on a laser-pretreated metallic target.

PubMed

Niu, Sheng; Zheng, Lijuan; Khan, Abdul Qayyum; Feng, Guang; Zeng, Heping

2018-03-01

A fast and sensitive analysis for trace level heavy metals in aqueous solution was realized by using an improved laser induced breakdown spectroscopy (LIBS) methodology. Solutions containing heavy metal elements, Ni, Cr, and Cd, were concentrated in a laser-pretreated area (25 × 20mm 2 ) of a polished aluminum target surface, wherein pretreated grooves enabled homogeneous distribution of the metallic solutions in the well-defined area, and laser ablation of the aluminum target produced unique plasma excitation of various metallic ions. For 1-mL solutions deposited, we obtained an analytical precision of about 7% relative standard deviation (RSD), and limits of detection (LODs) of 22, 19, and 184μg/L for Ni, Cr, and Cd, respectively. Moreover, the laser-pretreated metallic microstructure allowed more solution deposited with the help of a hot plate, which supported improvement of LODs to sub-μg/L level for Cr and Ni and μg/L level for Cd with about 20-mL solution engaged in the enrichment processes. The applicability of the proposed methodology was validated on certified reference materials and real river water. Copyright © 2017 Elsevier B.V. All rights reserved.

Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

PubMed

Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

2017-10-06

Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

Identification of heavy metal origins related to chemical and morphological soil properties using several non-destructive X-ray analytical methods.

PubMed

Akbulut, Songul; Grieken, Renevan; Kılıc, Mehmet A; Cevik, Ugur; Rotondo, Giuliana G

2013-03-01

Soils are complex mixtures of organic, inorganic materials, and metal compounds from anthropogenic sources. In order to identify the pollution sources, their magnitude and development, several X-ray analytical methods were applied in this study. The concentrations of 16 elements were determined in all the soil samples using energy dispersive X-ray fluorescence spectrometry. Soils of unknown origin were observed by scanning electron microscopy equipped with a Si(Li) X-ray detector using Monte Carlo simulation approach. The mineralogical analyses were carried out using X-ray diffraction spectrometry. Due to the correlations between heavy metals and oxide compounds, the samples were analyzed also by electron probe microanalyzer (EPMA) in order to have information about their oxide contents. On the other hand, soil pH and salinity levels were identified owing to their influence between heavy metal and soil-surface chemistry. Moreover, the geoaccumulation index (I (geo)) enables the assessment of contamination by comparing current and pre-industrial concentrations.

Heavy metals found in the breathing zone, toenails and lung function of welders working in an air-conditioned welding workplace.

PubMed

Hariri, Azian; Mohamad Noor, Noraishah; Paiman, Nuur Azreen; Ahmad Zaidi, Ahmad Mujahid; Zainal Bakri, Siti Farhana

2017-09-22

Welding operations are rarely conducted in an air-conditioned room. However, a company would set its welding operations in an air-conditioned room to maintain the humidity level needed to reduce hydrogen cracks in the specimen being welded. This study intended to assess the exposure to metal elements in the welders' breathing zone and toenail samples. Heavy metal concentration was analysed using inductively coupled plasma mass spectrometry. The lung function test was also conducted and analysed using statistical approaches. Chromium and manganese concentrations in the breathing zone exceeded the permissible exposure limit stipulated by Malaysian regulations. A similar trend was obtained in the concentration of heavy metals in the breathing zone air sampling and in the welders' toenails. Although there was no statistically significant decrease in the lung function of welders, it is suggested that exposure control through engineering and administrative approaches should be considered for workplace safety and health improvement.

The impact of sewage sludge treatment on the content of selected heavy metals and their fractions.

PubMed

Ignatowicz, Katarzyna

2017-07-01

The aim of the study was to assess the physicochemical properties of compost made of municipal sewage sludge from selected Municipal Sewage Treatment Plant. Content of basic macroelements and heavy metals (Zn, Cu, Cr, Cd, Ni, Pb, Hg, Mg, Ca, N, P, K, Na) and their fractions was determined by means of BCR method. Based on the analyzes, it was found that the content of heavy metals in compost did not exceed the limits set by natural land management of sewage sludge; the compost is very abundant in biogenic elements - nitrogen and phosphorus - and it can be also considered a significant source of calcium and magnesium. The analysis of results obtained from the three-stage chemical extraction revealed that deposits subjected to aerobic stabilization and composting accumulate metals (in descending sequence) in fractions III and II, i.e. fractions virtually inaccessible to the ecosystem in optimal conditions of use. Copyright © 2017 Elsevier Inc. All rights reserved.

Health risks of heavy metals to the general public in Tianjin, China via consumption of vegetables and fish.

PubMed

Wang, Xilong; Sato, T; Xing, Baoshan; Tao, S

2005-11-01

Consumption of vegetables and fish contaminated with the heavy metals Cu, Zn, Pb, Cd, Hg, and Cr is the most likely route for human exposure in Tianjin, China. Health risks associated with these heavy metals were assessed based on the target hazard quotients (THQs), which can be derived from concentrations of heavy metals in vegetables and fish consumed in four districts (Dong Li, Xi Qing, Jin Nan, and Bei Chen) and the urban area of Tianjin, China. Individual metal THQ (<1) values indicate the relative absence of health risks associated with intake of a single heavy metal through consumption of either contaminated vegetables or fish only. However, consumption of both vegetables and fish would lead to potential health risks especially for children, since individual THQs for vegetables and fish would sum up to almost 1. If individual THQs resulting from crops consumption are considered, the health risks would be greater for children since the THQ values will always be >1. Risk contribution from Cr is minimal compared to the other elements. Hg is the major risk contributor for children in Bei Chen since the THQ contribution amounts to about 45% of the total THQ values due to vegetables and fish consumption. The health risk to adults in Ding Li is ascribed mainly to the intake of Cd by vegetables and fish consumption, which contributes a substantial fraction to the total THQ (about 51%).

Remote sensing of soybean stress as an indicator of chemical concentration of biosolid amended surface soils

NASA Astrophysics Data System (ADS)

Sridhar, B. B. Maruthi; Vincent, Robert K.; Roberts, Sheila J.; Czajkowski, Kevin

2011-08-01

The accumulation of heavy metals in the biosolid amended soils and the risk of their uptake into different plant parts is a topic of great concern. This study examines the accumulation of several heavy metals and nutrients in soybeans grown on biosolid applied soils and the use of remote sensing to monitor the metal uptake and plant stress. Field and greenhouse studies were conducted with soybeans grown on soils applied with biosolids at varying rates. The plant growth was monitored using Landsat TM imagery and handheld spectroradiometer in field and greenhouse studies, respectively. Soil and plant samples were collected and then analyzed for several elemental concentrations. The chemical concentrations in soils and roots increased significantly with increase in applied biosolid concentrations. Copper (Cu) and Molybdenum (Mo) accumulated significantly in the shoots of the metal-treated plants. Our spectral and Landsat TM image analysis revealed that the Normalized Difference Vegetative Index (NDVI) can be used to distinguish the metal stressed plants. The NDVI showed significant negative correlation with increase in soil Cu concentrations followed by other elements. This study suggests the use of remote sensing to monitor soybean stress patterns and thus indirectly assess soil chemical characteristics.

Diffuse gas properties and stellar metallicities in cosmological simulations of disc galaxy formation

NASA Astrophysics Data System (ADS)

Marinacci, Federico; Pakmor, Rüdiger; Springel, Volker; Simpson, Christine M.

2014-08-01

We analyse the properties of the circumgalactic medium and the metal content of the stars comprising the central galaxy in eight hydrodynamical `zoom-in' simulations of disc galaxy formation. We use these properties as a benchmark for our model of galaxy formation physics implemented in the moving-mesh code AREPO, which succeeds in forming quite realistic late-type spirals in the set of `Aquarius' initial conditions of Milky-Way-sized haloes. Galactic winds significantly influence the morphology of the circumgalactic medium and induce bipolar features in the distribution of heavy elements. They also affect the thermodynamic properties of the circumgalactic gas by supplying an energy input that sustains its radiative losses. Although a significant fraction of the heavy elements are transferred from the central galaxy to the halo, and even beyond the virial radius, enough metals are retained by stars to yield a peak in their metallicity distributions at about Z⊙. All our default runs overestimate the stellar [O/Fe] ratio, an effect that we demonstrate can be rectified by an increase of the adopted Type Ia supernova rate. Nevertheless, the models have difficulty in producing stellar metallicity gradients of the same strength as observed in the Milky Way.

Nutrient metal elements in plants.

PubMed

DalCorso, Giovanni; Manara, Anna; Piasentin, Silvia; Furini, Antonella

2014-10-01

Plants need many different metal elements for growth, development and reproduction, which must be mobilized from the soil matrix and absorbed by the roots as metal ions. Once taken up by the roots, metal ions are allocated to different parts of the plant by the vascular tissues. Metals are naturally present in the soil, but human activities, ranging from mining and agriculture to sewage processing and heavy industry, have increased the amount of metal pollution in the environment. Plants are challenged by environmental metal ion concentrations that fluctuate from low to high toxic levels, and have therefore evolved mechanisms to cope with such phenomena. In this review, we focus on recent data that provide insight into the molecular mechanisms of metal absorption and transport by plants, also considering the effect of metal deficiency and toxicity. We also highlight the positive effects of some non-essential metals on plant fitness.

Regulation of essential heavy metals (Cu, Cr, and Zn) by the freshwater prawn macrobrachium malcolmsonii (Milne Edwards)

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

Vijayram, K.; Geraldine, P.

1996-02-01

Despite the low concentrations of heavy metals in the surrounding medium, aquatic organisms take them up and accumulate them in their soft tissues to concentrations several fold higher than those of ambient levels. Knowledge of accumulation patterns of a particular trace metal is a prerequisite for understanding the significance of an observed metal concentration in a particular animal, especially from the aspect of biomonitoring. Many marine invertebrates accumulate heavy metals without any regulation and the accumulation necessarily being associated with mechanisms to store the metals in a detoxified form. Two detoxification mechanisms have been described, both of which may occurmore » in one specimen. Heavy metals can either be bound up in insoluble metalliferous {open_quote}granules{close_quote}, or are bound to soluble metal-binding ligands, such as metallothioneins. Some marine decapod crustaceans have an innate ability to regulate the internal concentrations of essential but potentially toxic metals within a constant level, presumably to meet their metabolic demands. However, at present, there is no such information relating to freshwater decapod crustaceans, especially shrimps which occupy a totally different environment. Macrobrachium malcolmsonii, a potential aquaculture species for freshwater is found in abundance in one of the major Indian rivers, the Cauvery. In the present study, an attempt was made to determine whether the freshwater prawn, M. malcolmsonlii, is able to regulate the three essential elements, copper, chromium and zinc, over a wide range of dissolved concentrations. These three metals were chosen because the Cauvery River receives pollutants containing these metals.« less

Assessment of water-soluble thiourea-formaldehyde (WTF) resin for stabilization/solidification (S/S) of heavy metal contaminated soils.

PubMed

Liu, She-Jiang; Jiang, Jia-Yu; Wang, Shen; Guo, Yu-Peng; Ding, Hui

2018-03-15

Stabilization/Solidification (S/S) can be regarded as necessary for remediation of heavy metal contaminated soil. There is, however, solid agent is not very convenient to use. Water-soluble thiourea-formaldehyde (WTF) is a novel chelating agent, which has more practical applications. The process of WTF resin for S/S process of heavy metal contaminated soils was studied. Laboratory-prepared slurries, made of field soils spiked with Cd 2+ and Cr 6+ were treated with WTF resin. The toxicity characteristic leaching procedure (TCLP) showed that with 2 wt% WTF, in the neutral condition of soil after treatment for 7 d, the leaching concentrations of Cd 2+ and Cr 6+ in contaminated soil were decreased by 80.3% and 92.6% respectively. Moreover, Tessier sequence extraction procedure showed WTF resin reduced the leaching concentration by transforming heavy metal from exchange form to organic form. The structure of WTF is obtained according to elemental analysis result and reaction mechanism. Through analysis of the infrared spectrogram of WTF and WTF heavy mental chelating precipitation, WTF can form stable chelate with heavy mental through coordination. The significant groups are hydroxyl, nitrogen and sulphur function groups in WTF mainly. Toxicology test revealed that the WTF resin is nontoxic to microorganism in the soils. Copyright © 2017 Elsevier B.V. All rights reserved.

The R-process Alliance: First Release from the Southern Search for R-process-enhanced Stars in the Galactic Halo

NASA Astrophysics Data System (ADS)

Hansen, Terese T.; Holmbeck, Erika M.; Beers, Timothy C.; Placco, Vinicius M.; Roederer, Ian U.; Frebel, Anna; Sakari, Charli M.; Simon, Joshua D.; Thompson, Ian B.

2018-05-01

The recent detection of a binary neutron star merger and the clear evidence of the decay of radioactive material observed in this event have, after 60 years of effort, provided an astrophysical site for the rapid neutron-capture (r-) process which is responsible for the production of the heaviest elements in our universe. However, observations of metal-poor stars with highly enhanced r-process elements have revealed abundance patterns suggesting that multiple sites may be involved. To address this issue, and to advance our understanding of the r-process, we have initiated an extensive search for bright (V < 13.5), very metal-poor ([Fe/H] < ‑2) stars in the Milky Way halo exhibiting strongly enhanced r-process signatures. This paper presents the first sample collected in the southern hemisphere using the echelle spectrograph on du Pont 2.5 m telescope at Las Campanas Observatory. We have observed and analyzed 107 stars with ‑3.13 < [Fe/H] < ‑0.79. Of those, 12 stars are strongly enhanced in heavy r-process elements (r-II), 42 stars show moderate enhancements of heavy r-process material (r-I), and 20 stars exhibit low abundances of the heavy r-process elements and higher abundances of the light r-process elements relative to the heavy ones (limited-r). This search is more successful at finding r-process-enhanced stars compared to previous searches, primarily due to a refined target selection procedure that focuses on red giants. This paper includes data gathered with the 2.5 m du Pont telescope located at Las Campanas Observatory, Chile.

The assessment of bore-hole water quality of Kakamega County, Kenya

NASA Astrophysics Data System (ADS)

Christine, Adika A.; Kibet, Joshua K.; Kiprop, Ambsrose K.; Were, Munyendo L.

2018-03-01

Numerous deleterious impacts of anthropogenic activities on water quality are typically observed in areas bursting with mineral exploitation, agricultural activities, and industrial processes. Therefore, this contribution details the water quality and water origin in selected hand-dug wells of one the most prominent mining areas in Kenya (Kakamega County). The toxicological impacts of drinking water from a mining site may include cancer and genetic aberrations largely because of the toxic effects of waterborne metals including Hg and As. Accordingly, this study focuses primarily on the investigation of heavy metals, essential elements such as Na and K. Heavy metals and essential elements were determined using spectroscopic and titrimetric techniques. The study revealed that mercury (Hg) concentration ranged between 0.00256 and 0.0611 ± 0.00005 mg/L while arsenic (As) concentration ranged from 0.0103 to 0.0119 ± 0.00005 mg/L. The concentration of potassium ranged from 2.53 to 4.08 ± 0.15 mg/L while that of sodium varied from 6.74 to 9.260 ± 0.2 mg/L. Although the concentration of cadmium was lower than that recommended by W.H.O, the concentrations of Hg, Pb, and As in Kakamega waters were higher than the internationally accepted levels. The generally high level of heavy metals in Kakamega bore-hole waters is, therefore, a public health concern that needs immediate intervention.

Modified clay sorbents for wastewater treatment and immobilization of heavy metals in soils

NASA Astrophysics Data System (ADS)

Burlakovs, Juris; Klavins, Maris; Vincevica-Gaile, Zane; Stapkevica, Mara

2014-05-01

Soil and groundwater pollution with heavy metals is the result of both, anthropogenic and natural processes in the environment. Anthropogenic influence in great extent appears from industry, mining, treatment of metal ores and waste incineration. Contamination of soil and water can be induced by diffuse sources such as applications of agrochemicals and fertilizers in agriculture, air pollution from industry and transport, and by point sources, e.g., wastewater streams, runoff from dump sites and factories. Treatment processes used for metal removal from polluted soil and water include methodologies based on chemical precipitation, ion exchange, carbon adsorption, membrane filtration, adsorption and co-precipitation. Optimal removal of heavy metal ions from aqueous medium can be achieved by adsorption process which is considered as one of the most effective methods due to its cost-effectiveness and high efficiency. Immobilization of metals in contaminated soil also can be done with different adsorbents as the in situ technology. Use of natural and modified clay can be developed as one of the solutions in immobilization of lead, zinc, copper and other elements in polluted sites. Within the present study clay samples of different geological genesis were modified with sodium and calcium chlorides, iron oxyhydroxides and ammonium dihydrogen phosphate in variable proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of metals by sorption and batch leaching tests. Sorption capacity for raw clay samples was considered as relatively lower referring to the modified species of the same clay type. In addition, clay samples were tested for powder X-ray difractometry, cation exchange, surface area properties, elemental composition, as well as scanning electron microscopy pictures of clay sample surface structures were obtained. Modified clay sorbents were tested for sorption of lead as monocontaminant and for complex contamination of heavy metals. The highest sorption capacity was observed for clay modified with hydroxyapatite and calcium salts. Sorption capacity increased with a rise of temperature; the best pH value for sorption was 5. Immobilization of metals in soil, as well as industrial wastewater treatment can be accomplished by using sorbents on modified clay basis.

Concentration method for the spectrochemical determination of seventeen minor elements in natural water

USGS Publications Warehouse

Silvey, W.D.; Brennan, R.

1962-01-01

A method for the quantitative spectrochemical determination of microgram amounts of 17 minor elements in water is given. The chelating reagents 8-quinolinol, tannic acid, and thionalide are utilized to concentrate traces (1 to 500 ??g.) of aluminum, cobalt, chromium, copper, iron, gallium, germanium, manganese, nickel, titanium, vanadium, bismuth, lead, molybdenum, cadmium, zinc, and beryllium. Indium is added as a buffer, and palladium is used as an internal standard. The ashed oxides of these 17 metals are subsequently subjected to direct current arcing conditions during spectrum analysis. The method can be used to analyze waters with dissolved solids ranging from less than 100 to more than 100,000 p.p.m. There is no limiting concentration range for the determination of the heavy metals since any volume of sample can be used that will contain a heavy metal concentration within the analytical range of the method. Both the chemical and spectrographic procedures are described, and precision and accuracy data are given.

Adsorption of oils, heavy metals and dyes by recovered carbon powder from spent pot liner of aluminum smelter plant.

PubMed

Mazumder, B; Devi, Sasmita Rani

2008-07-01

Aluminum smelter plants employ Hall-Heroult electrolysis cells for electrolysis of molten cryolite to recover aluminum metal by electrolysis. These cells use carbon cathode blocks as a lining material inside. At the end of service life of the cells, pot lines are discarded and new carbon blocks are laid for fresh charging. These used carbon cathode blocks, known as spent pot liners, are heavily infested with toxic elements such as fluoride, cyanide, alkali, etc. Therefore, their disposal in open field poses great environmental risk. A simple process has been developed for decontamination of these spent pot liners and to recover its carbon value. The experiments indicated that this carbon, in the form of fine powder (around 20 micron in size) can absorb toxic elements like heavy metals, dyes, oils, etc. to a great extent and thus can be used for mitigating environmental pollution occuring due to various toxic wastes.

Compton suppression method and epithermal NAA in the determination of nutrients and heavy metals in Nigerian food and beverages.

PubMed

Ahmed, Y A; Landsberger, S; O'Kelly, D J; Braisted, J; Gabdo, H; Ewa, I O B; Umar, I M; Funtua, I I

2010-10-01

We used in this study Compton suppression method and epithermal neutron activation analysis to determine the concentration of nutrients and heavy metals in Nigerian food and beverages. The work was performed at the University of Texas TRIGA Reactor by short, medium, and long irradiation protocols, using thermal flux of 1.4x10(12)n cm(-2)s(-1) and epithermal flux of 1.4x10(11)n cm(-2)s(-1). Application of Compton suppression method has reduced interferences from Compton scattered photons thereby allowing easy evaluation of Na, Cl, Ca, Cu, Mn, Mg, Co, Cr, Rb, Fe, and Se. The epithermal NAA method has enabled determination of Cd, As, Ba, Sr, Br, I, and V with little turn-around time. Quality Control and Quality Assurance of the method was tested by analyzing four Standard Reference Materials (non-fat powdered milk, apple leaves, citrus leaves, and peach leaves) obtained from National Institute for Standards and Technology. Our results show that sorghum, millet, and maize have high values of Zn, Mn, Fe, low values of Cd, As, and Se. Powdered milks, rice, beans, and soybeans were found to have moderate amounts of all the elements. Tobacco recorded high content of Cd, Mn, and As, whereas tea, tsobo leaves, Baobab leaves, and okro seed have more As values than others. However, biscuits, macaroni, spaghetti, and noodles show lower concentrations of all the elements. The distribution of these nutrients and heavy metals in these food and beverages shows the need to fortify biscuits and pastas with micro and macro-nutrients and reduce the use of tobacco, tea, tsobo leaves, Baobab leaves, and Okro seed to avoid intake of heavy elements. Copyright 2010 Elsevier Ltd. All rights reserved.

Migration of some metals in the ecosystem of the Caspian sea

NASA Astrophysics Data System (ADS)

Chaplygin, Wladimir A.; Tanasova, Anastasia S.; Ershova, Tatiana S.; Zaitsev, Vyacheslav F.; Bech, Jaume; Roca, Núria

2017-04-01

The content of heavy metals in aquatic organisms of the Caspian sea is connected with the increase of anthropogenic load on aqueous ecosystems, what leads to the disruption of the natural cycle of chemical elements. Heavy metals in small concentrations are included in an organism and are involved in various metabolic processes. One of the reasons for the high content of metals in the body of hydrobionts is the accumulation of the last in the food web and functional disturbance in all parts of the ecosystem. The aim of this work was to trace the migration of some metals in trophic chains in the ecosystem of the Caspian sea. The objects of the study were: various types of soils of the Caspian sea molluscs of the genus Didacna, fish - gobies ceneйcTвa Gobiidae and liver of Russian sturgeon Acipenser gueldenstaedtii, mammal - the liver of the Caspian seal Phoca caspica. The main burden of the accumulation of trace elements takes on the liver, which is a functional depot of many metals and is characterized by high metabolic activity in which there is a filtering and transformation of substances. The content of heavy metals in the objects of study were determined by atomic absorption method. The results are presented in mg/kg dry matter. The results showed that the level of accumulation of heavy metals in different types of soils of the Caspian sea was within the limits of environmental standards for bottom sediments taken in the Netherlands (2009) and heavy metal concentrations in silt and sand soil were below background values (according Verkhnevolzhskaya exploration of the enterprise and the Institute of water problems Russian Academy of Sciences, Russia). It should be noted that silty and sandy soils have a similar distribution pattern of heavy metals. A number of decrease the content of heavy metals in different soils of the Caspian sea were as follows: Silty and sandy soils: Zn>Ni>Pb>Co>Cd>Hg. The metals content in mollusks decreases in the series: Zn>Ni>Cd>Pb>Co>Hg. Decreasing the number of heavy metals content in steers as follows: Zn>Ni>Pb>Co>Cd>Hg, in the liver of Russian sturgeon: Zn>Ni>Pb>Cd>Co>Hg. It should be noted that in living objects Zn and Ni is accumulated to a greater extent in comparison with the other investigated metals. Apparently, this is due to their close contact with sediments, which have previously drawn attention N.V. Kuznetsova (2015) and N. Yu. Yevtushenko (1996). And mollusks, have the most intimate contact with the soil, have accumulated zinc and Nickel at higher concentrations (79.73 ± 2.18 mg/kg and 59.97 ± of 9.29 mg/kg, respectively), compared with fishs. In living organisms revealed the migration of mercury through trophic levels. If the concentration of mercury in sandy soil to make per unit, it is possible to obtain the following ratios: sand soil ×1 < mollusks ×5< gobies ×10< hepar Russian sturgeon ×70 < Caspian seal × 2000. Mercury forms a very stable mercury-organic complexes, displacing biological molecules, almost all other metals. This property of mercury causes an irreversible increase in its concentration in the transition to the trophic chain of organisms from lower links (mollusks) to high (Caspian seal). Shellfish have a high ability to remove heavy metals from soil, especially from sandy. Therefore, they have a high bioaccumulation factors (Zn - 7, Ni - 7, Cd - 4, Hg - 5) while the fish significant coefficients of bioaccumulation was noted in only a handful of metals: gobies (Hg - 2), Russian sturgeon (Cd - 2.5 and Hg - 7). Thus, the bioaccumulation potential of metals depends on species physiological characteristics of the organisms and environmental factors.

Cysteine-Functionalized Chitosan Magnetic Nano-Based Particles for the Recovery of Light and Heavy Rare Earth Metals: Uptake Kinetics and Sorption Isotherms

PubMed Central

Galhoum, Ahmed A.; Mafhouz, Mohammad G.; Abdel-Rehem, Sayed T.; Gomaa, Nabawia A.; Atia, Asem A.; Vincent, Thierry; Guibal, Eric

2015-01-01

Cysteine-functionalized chitosan magnetic nano-based particles were synthesized for the sorption of light and heavy rare earth (RE) metal ions (La(III), Nd(III) and Yb(III)). The structural, surface, and magnetic properties of nano-sized sorbent were investigated by elemental analysis, FTIR, XRD, TEM and VSM (vibrating sample magnetometry). Experimental data show that the pseudo second-order rate equation fits the kinetic profiles well, while sorption isotherms are described by the Langmuir model. Thermodynamic constants (ΔG°, ΔH°) demonstrate the spontaneous and endothermic nature of sorption. Yb(III) (heavy RE) was selectively sorbed while light RE metal ions La(III) and Nd(III) were concentrated/enriched in the solution. Cationic species RE(III) in aqueous solution can be adsorbed by the combination of chelating and anion-exchange mechanisms. The sorbent can be efficiently regenerated using acidified thiourea. PMID:28347004

[Dynamics of heavy metals in the holocene aeolian loess-soil profile in the upper-reaches of the Huaihe River].

PubMed

He, Zhong; Huang, Chun-chang; Pang, Jiang-li; Wang, Li-jun; Li, Xin-yan

2006-07-01

Upon the exploration and research in the field, we determined the content of Pb, Zn, Cu, Mn, Cr, Co, Ni, Ti, V, Nb at YPC loess-soil site on the X-ray Fluorescence. In the stage of loess accumulation, the content of these heavy metals are very low and the variances are very little, which can be served as the background value of paleosol formation. In the stage of Holocene Megathermal, the content of these heavy metals are increased greatly, because the eluviations and transmigrations of freely soluble elements under warm and humidity environment. In the stage of modern soil( MS), the content of Pb are increased gradually, and there are abruptly increase in the depth of 8cm below the ground, which are the records of sedimentation and accumulation of atmospheric pollutant.

Sequential chemical extraction for a phosphogypsum environmental impact evaluation

NASA Astrophysics Data System (ADS)

Gennari, R. F.; Garcia, I.; Medina, N. H.; Silveira, M. A. G.

2013-05-01

Phosphogypsum (PG) is gypsum generated during phosphoric acid production. PG is stocked in large stacks or accumulated in lakes; it contains heavy metals and naturally occurring radioactive elements. The metal contamination may affect the functionality, sustainability and biodiversity of ecosystems. In this work, PG samples were analyzed by Plasma Spectrometry. Total metal content and in the extractable fraction of chemical elements were determined. For K, Ni, Zn, Cr, Cd, Ba, Pb and U, the results obtained are lower than those obtained in a Idaho plant are including and also lower than those found in the soil, indicating this PG sample analyzed probably will not cause any additional metal neither natural radiation contamination.

Metal contamination status of the soil-plant system and effects on the soil microbial community near a rare metal recycling smelter.

PubMed

Li, Zhu; Ma, Tingting; Yuan, Cheng; Hou, Jinyu; Wang, Qingling; Wu, Longhua; Christie, Peter; Luo, Yongming

2016-09-01

Four heavy metals (Cd, Cu, Pb and Zn), two metalloids (As and Sb) and two rare metals (In and Tl) were selected as target elements to ascertain their concentrations and accumulation in the soil-plant system and their effects on the structure of the soil microbial community in a typical area of rare metal smelting in south China. Twenty-seven soil samples 100, 500, 1000, 1500 and 3000 m from the smelter and 42 vegetable samples were collected to determine the concentrations of the target elements. Changes in soil micro-organisms were investigated using the Biolog test and 454 pyrosequencing. The concentrations of the eight target elements (especially As and Cd) were especially high in the topsoil 100 m from the smelter and decreased markedly with increasing distance from the smelter and with increasing soil depth. Cadmium bio-concentration factors in the vegetables were the highest followed by Tl, Cu, Zn, In, Sb, Pb, and then As. The concentrations of As, Cd and Pb in vegetables were 86.7, 100 and 80.0 %, respectively, over the permissible limits and possible contamination by Tl may also be of concern. Changes in soil microbial counts and average well colour development were also significantly different at different sampling distances from the smelter. The degree of tolerance to heavy metals appears to be fungi > bacteria > actinomycetes. The 454 pyrosequencing indicates that long-term metal contamination from the smelting activities has resulted in shifts in the composition of the soil bacterial community.

Localization of heavy metals immobilized on specific organic and mineral parts of a wood-derived biochar

NASA Astrophysics Data System (ADS)

Rees, Frédéric; Watteau, Françoise; Morel, Jean-Louis

2013-04-01

Biochar has been intensively investigated over recent years, not only as a promising carbon sequestration or fertilizing agent in soils but also as a possible new sorbent to remediate contaminated soils. A few studies have revealed its high potential for heavy metals immobilization depending on the nature of biochar and trace elements. The mechanisms behind this immobilization remain however unclear: some authors have hypothesized a high sorption capacity due to biochar large surface area while others have suggested that this immobilization is mainly due to soil pH increase. In particular, the distinction between heavy metals specific sorption in biochar pores and heavy metals precipitation in or outside biochar particles is often impossible to make while it is of primary importance to evaluate biochar ability to retain these pollutants on a long-time scale. In order to evaluate the main heavy metal immobilization effects on a standard biochar and to identify the most successful biochar parts of the sample, we examined biochar particles after heavy metals immobilization in batch experiments designed to mimic real chemical processes in soils. A biochar derived from hard and soft wood and pyrolyzed at about 450°C was put in contact with relatively low concentrations of heavy metals (Pb, Cu, Cd, Zn, Ni) in an initially acidic Ca(NO3)2 solution. Following a one-week adsorption and a one-week desorption step, we recovered the biochar particles and observed them using scanning electron microscopy coupled to energy dispersive x-ray spectroscopy, focusing especially on the changes in mineral phases and the location of each of the retained heavy metals on biochar particles. We were able to distinguish different structures in the biochar samples which were linked to the degree of pyrolysis and the exact nature of the raw wood biomass. We detected the presence of concentrated metals zones (e.g. lead) in specific locations of the organic particles depending on the original plant tissues, and enlightened metal associations with newly-formed mineral phases such as calcite present on biochar surface. These observations provide new insights in the understanding of metal immobilization mechanisms on biochar such as precipitation and co-precipitation. Our findings also underline the need to consider the heterogeneity of biochar constitution for optimizing the remediation potential of biochar on contaminated sites.

Pre-supernova models for massive stars produced with large nuclear reaction network by MESA

NASA Astrophysics Data System (ADS)

Park, Byeongchan; Kwak, Kyujin

2018-04-01

Core-collapsed Supernova (CCSN) is one of violent phenomena in the universe. CCSN generates heavy elements and leaves a neutron star behind. It has been known that the physical properties of CCSN depend on those of pre-supernova such as mass, metallicities including distribution of elements, and the density and temperature profile which are obtained from the stellar evolution calculation. In particular, the production of heavy elements in CCSN is sensitive to the abundance profiles in the pre-supernova models. In this study, we evolve a massive main sequence star with 15Msun and solar metallicity to the pre-supernova stage by using two different networks, small and large. The large nuclear reaction network includes more than four times isotopes than the small network. Our calculations were done by MESA (Modules for Experiments in Stellar Astrophysics) which allowed us to use the large network containing about a hundred isotopes. We compare the results obtained with two networks.

LIBS coupled with ICP/OES for the spectral analysis of betel leaves

NASA Astrophysics Data System (ADS)

Rehan, I.; Rehan, K.; Sultana, S.; Khan, M. Z.; Muhammad, R.

2018-05-01

Laser-induced breakdown spectroscopy (LIBS) system was optimized and was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air. Pulsed Nd:YAG (1064 nm) in conjunction with a suitable detector (LIBS 2000+, Ocean Optics, Inc) having the optical resolution of 0.06 nm was used to record the emission spectra from 200 to 720 nm. Elements like Al, Ba, Ca, Cr, Cu, P, Fe, K, Mg, Mn, Na, P, S, Sr, and Zn were found to be present in the samples. The abundances of observed elements were calculated through normalized calibration curve method, integrated intensity ratio method, and calibration free-LIBS approach. Quantitative analyses were accomplished under the assumption of local thermodynamic equilibrium (LTE) and optically thin plasma. LIBS findings were validated by comparing its results with the results obtained using a typical analytical technique of inductively coupled plasma-optical emission spectroscopy (ICP/OES). Limit of detection (LOD) of the LIBS system was also estimated for heavy metals.

Essential and toxic elements in honeys from a region of central Italy.

PubMed

Meli, M A; Desideri, D; Roselli, C; Benedetti, C; Feduzi, L

2015-01-01

Levels of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), zinc (Zn), mercury (Hg), cadmium (Cd), and lead (Pb) in several types of honey produced in a region of Central Italy were determined by atomic absorption spectroscopy (AAS). The degree of humidity, sugar content, pH, free acidity, combined acidity (lactones), and total acidity were also measured. These elements were found to be present in honey in various proportions depending upon (1) the area foraged by bees, (2) flower type visited for collection of nectar, and (3) quality of water in the vicinity of the hive. Strong positive correlations occurred between Pb and Hg, Pb and Cd, Pb and Fe, Pb and Cr, Hg and Cd, and Hg and Fe. The honey products synthesized in Central Italy were of good quality, but not completely free of heavy metal contamination. Compared with established recommended daily intakes, heavy metals or trace element intoxication following honey consumption in Italy was found not to be a concern for human health.

[Determination of trace metals in atmospheric dry deposition with a heavy matrix of PUF by inductively coupled plasma mass spectroscopy after microwave digestion].

PubMed

Pan, Yue-peng; Wang, Yue-si; Yang, Yong-jie; Wu, Dan; Xin, Jin-yuan; Fan, Wen-yan

2010-03-01

Interest in atmospheric dry deposition results mostly from concerns about the effects of the deposited trace elements entering waterbody, soil and vegetation as well as their subsequent health effects. A microwave assisted digestion method followed by inductively coupled plasma mass spectrometric (MAD-ICP/MS) analysis was developed to determine the concentrations of a large number of trace metals in atmospheric dry deposition samples with a heavy matrix of polyurethane foam (PUF). A combination of HNO3-H2O2-HF was used for digestion. The experimental protocol for the microwave assisted digestion was established using two different SRMs (GBW 07401, Soil and GBW 08401, Coal fly ash). Subsequently, blanks and limits of detection for total trace metal concentrations were determined for PUF filter which was used for dry deposition sampling. Finally, the optimized digestion method was applied to real world atmospheric dry deposition samples collected at 10 sites in Jingjinji area in winter from Dec. 2007 to Feb. 2008. The results showed that the area-averaged total mass fluxes ranged between 85 and 912 mg x (m2 x d)(-1), and fluxes of most elements were highest at Baoding and lowest at Xinglong. In addition, the elemental fluxes in urban areas of Beijing, Tianjin and Tangshan were measured to be higher than that in suburb and rural sites. The average fluxes of crust elements (A1, Fe, Mn, K, Na, Ca and Mg) were one to three orders of magnitude higher than anthropogenic elements (Cu, Pb, Cr, Ni, V, Zn and Ba), varying from 151 to 16034 microg x (m2 x d)(-1) versus 14 to 243 microg x (m2 x d)(-1). Zinc was the most abundant heavy metal and calcium the highest of the crust elements while the elements Mo, Co, Cd, As and Be deposited less or even could not be detected. The anthropogenic and crustal contributions were estimated by employing enrichment factors (EF) calculated relative to the average crustal composition. The EF values of all elements except Pb and Zn were below 10, suggesting that local soil and/or dust generally dominate in the dry deposition flux.

Preconcentration of heavy metals on activated carbon and their determination in fruits by inductively coupled plasma optical emission spectrometry.

PubMed

Feist, Barbara; Mikula, Barbara

2014-03-15

A method of separation and preconcentration of cadmium, cobalt, copper, nickel, lead, and zinc at trace level using activated carbon is proposed. Activated carbon with the adsorbed trace metals was mineralised using a high-pressure microwave mineraliser. The heavy metals were determined after preconcentration by inductively coupled plasma optical emission spectrometry (ICP-OES). The influence of several parameters, such as pH, sorbent mass, shaking time was examined. Moreover, effects of inorganic matrix on recovery of the determined elements were studied. The experiment shows that foreign ions did not influence recovery of the determined elements. The detection limits (DL) of Cd, Co, Cu, Ni, Pb, and Zn were 0.17, 0.19, 1.60, 2.60, 0.92 and 1.50 μg L(-)(1), respectively. The recovery of the method for the determined elements was better than 95% with relative standard deviation from 1.3% to 3.7%. The preconcentration factor was 80. The proposed method was applied for determination of Cd, Co, Cu, Ni, Pb, and Zn in fruits materials. Accuracy of the proposed method was verified using certified reference material (NCS ZC85006 Tomato). Copyright © 2013 Elsevier Ltd. All rights reserved.

Heavy metal contamination from gold mining recorded in Porites lobata skeletons, Buyat-Ratototok district, North Sulawesi, Indonesia.

PubMed

Edinger, Evan N; Azmy, Karem; Diegor, Wilfredo; Siregar, P Raja

2008-09-01

Shallow marine sediments and fringing coral reefs of the Buyat-Ratototok district of North Sulawesi, Indonesia, are affected by submarine disposal of tailings from industrial gold mining and by small-scale gold mining using mercury amalgamation. Between-site variation in heavy metal concentrations in shallow marine sediments was partially reflected by trace element concentrations in reef coral skeletons from adjacent reefs. Corals skeletons recorded silicon, manganese, iron, copper, chromium, cobalt, antimony, thallium, and lead in different concentrations according to proximity to sources, but arsenic concentrations in corals were not significantly different among sites. Temporal analysis found that peak concentrations of arsenic and chromium generally coincided with peak concentrations of silica and/or copper, suggesting that most trace elements in the coral skeleton were incorporated into detrital siliciclastic sediments, rather than impurities within skeletal aragonite.

[Evaluation of pollution of an urban area by level of heavy metals in snow cover].

PubMed

Stepanova, N V; Khamitova, R Ia; Petrova, R S

2003-01-01

The goal of this study was to systematize various methodological approaches to evaluating the contamination of the snow cover with heavy metals (HM) by using Kazan, an industrial city with diversified industry, as an example. The findings suggest that it is necessary to characterize the contamination of the snow cover by the actual entrance of an element per area unit of the snow cover for a definite period of time rather than by the concentration of TM in the volume unit of snow water (mg/l), which minimizes the uncertainties with spatial and temporary snow cover variations. The index of the maximum allowable entrance, which is of practical value, may be used to objectively calibrate the pollution of the snow cover, by estimating the amount of a coming element and its toxicity.

[Distribution and pollution assessment of heavy metals in soil of relocation areas from the Danjiangkou Reservoir].

PubMed

Zhang, Lei; Qin, Yan-Wen; Zheng, Bing-Hui; Shi, Yao; Han, Chao-Nan

2013-01-01

The aim of this article is to explore the pollution level and potential ecological risk of heavy metals in soil of the relocation areas from the Danjiangkou Reservoir. The contents and spatial distribution of Cd, Pb, Cu, Zn, Cr and As in soil of the relocation areas from the Danjiangkou Reservoir were analyzed. The integrated pollution index and potential ecological risk index were used to evaluate the contamination degree and potential ecological risk of these elements. The results indicated that the average contents of Cd, Pb, Cu, Zn, Cr and As in the samples were 0.61, 23.11, 58.25, 22.65, 58.99 and 16.95 mg x kg(-1), respectively. Compared with the background value of soils from Henan province, all these 6 elements except Zn were enriched to some extent, especially Cd. Similar patterns were observed for the spatial distribution of Cu, Zn, and Pb. Compared with the contents of heavy metals in surface sediments of the typical domestic reservoirs, Cd and As in soil of the relocation areas from the Danjiangkou Reservoir were heavily accumulated. The correlation analysis showed that there were significant positive correlations among Pb, Cu, and Zn. And there was also significant positive correlation between Cr and Pb. In contrast, negative correlation was found between Cr and As. To sum up, the comprehensive assessment results showed that Cd was the primary element with high ecological risk.

Environmental impacts of heavy metals, rare earth elements and natural radionuclides in marine sediment from Ras Tanura, Saudi Arabia along the Arabian Gulf.

PubMed

El-Taher, Atef; Alshahri, Fatimh; Elsaman, Reda

2018-02-01

Ras Tanura city is one of the most important cities in Saudi Arabia because of the presence of the largest and oldest oil refinery in the Middle East which was began operations in September 1945. Also its contains gas plant and two ports. The concentration of natural radionuclides, heavy metals and rare earth elements were measured in marine sediment samples collected from Ras Tanura. The specific activities of 238 U, 226 Ra, 232 Th, 40 K and 137 Cs (Bq/kg) were measured using A hyper-pure Germanium detector (HPGe), and ranged from (20.4 ± 4.0-55.1 ± 9.9), (6.71 ± 0.7-46.1 ± 4.5), (3.51 ± 0.5-18.2 ± 1.5), (105 ± 4.4-492 ± 13) and from (0.33 ± 0.04-2.10 ± 0.4) for 238 U, 226 Ra, 232 Th, 40 K and 137 Cs respectively. Heavy metals and rare earth elements were measured using ICPE-9820 Plasma Atomic Emission Spectrometer. Also the frequency distributions for all radioactive variables in sediment samples were analyzed. Finally the radiological hazards due to natural radionuclides in marine sediment were calculated to the public and it's diagramed by Surfer program in maps. Comparing with the international recommended values, its values found to be within the international level. Copyright © 2017 Elsevier Ltd. All rights reserved.

HAT-P-26b: A Neptune-mass Exoplanet with Primordial Solar Heavy Element Abundance

NASA Astrophysics Data System (ADS)

Wakeford, Hannah R.; Sing, David K.; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric; Tremblin, Pascal; Skalid Amundsen, David; Lewis, Nikole K.; Mandell, Avi; Fortney, Jonathan J.; Knutson, Heather; Benneke, Björn; Evans, Tom M.

2017-01-01

A trend in giant planet mass and atmospheric heavy elemental abundance was first noted last century from observations of planets in our own solar system. These four data points from Jupiter, Saturn, Uranus, and Neptune have served as a corner stone of planet formation theory. Here we add another point in the mass-metallicity trend from a detailed observational study of the extrasolar planet HAT-P-26b, which inhabits the critical mass regime near Neptune and Uranus. Neptune-sized worlds are among the most common planets in our galaxy and frequently exist in orbital periods very different from that of our own solar system ice giants. Atmospheric studies are the principal window into these worlds, and thereby into their formation and evolution, beyond those of our own solar system. Using the Hubble Space Telescope and Spitzer, from the optical to the infrared, we conducted a detailed atmospheric study of the Neptune-mass exoplanet HAT-P-26b over 0.5 to 4.5 μm. We detect prominent H2O absorption at 1.4 μm to 525 ppm in the atmospheric transmission spectrum. We determine that HAT-P-26b’s atmosphere is not rich in heavy elements (≈1.8×solar), which goes distinctly against the solar system mass-metallicity trend. This likely indicates that HAT-P-26b’s atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime with little contamination from metal-rich planetesimals.

HAT-P-26b: A Neptune-mass Exoplanet with Primordial Solar Heavy Element Abundance

NASA Astrophysics Data System (ADS)

Wakeford, Hannah; Sing, David; Deming, Drake; Kataria, Tiffany; Lopez, Eric

2016-10-01

A trend in giant planet mass and atmospheric heavy elemental abundance was first noted last century from observations of planets in our own solar system. These four data points from Jupiter, Saturn, Uranus, and Neptune have served as a corner stone of planet formation theory. Here we add another point in the mass-metallicity trend from a detailed observational study of the extrasolar planet HAT-P-26b, which inhabits the critical mass regime near Neptune and Uranus. Neptune-sized worlds are among the most common planets in our galaxy and frequently exist in orbital periods very different from that of our own solar system ice giants. Atmospheric studies are the principal window into these worlds, and thereby into their formation and evolution, beyond those of our own solar system. Using the Hubble Space Telescope and Spitzer, from the optical to the infrared, we conducted a detailed atmospheric study of the Neptune-mass exoplanet HAT-P-26b over 0.5 to 4.5 μm. We detect prominent H2O absorption at 1.4 μm to 525 ppm in the atmospheric transmission spectrum. We determine that HAT-P-26b's atmosphere is not rich in heavy elements (≈1.8×solar), which goes distinctly against the solar system mass-metallicity trend. This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime with little contamination from metal-rich planetesimals.

Distribution of Major and Trace Elements in a Tropical Hydroelectric Reservoir in Sarawak, Malaysia.

PubMed

Sim, Siong Fong; Ling, Teck Yee; Nyanti, Lee; Ean Lee, Terri Zhuan; Mohd Irwan Lu, Nurul Aida Lu; Bakeh, Tomy

2014-01-01

This paper reports the metals content in water, sediment, macroalgae, aquatic plant, and fish of Batang Ai Hydroelectric Reservoir in Sarawak, Malaysia. The samples were acid digested and subjected to atomic absorption spectrometry analysis for Na, K, Mn, Cr, Ni, Zn, Mg, Fe, Sn, Al, Ca, As, Se, and Hg. The total Hg content was analysed on the mercury analyser. Results showed that metals in water, sediment, macroalgae, aquatic plant, and fish are distinguishable, with sediment and biota samples more susceptible to metal accumulation. The distributions of heavy metals in water specifically Se, Sn, and As could have associated with the input of fish feed, boating, and construction activities. The accumulation of heavy metals in sediment, macroalgae, and aquatic plant on the other hand might be largely influenced by the redox conditions in the aquatic environment. According to the contamination factor and the geoaccumulation index, sediment in Batang Ai Reservoir possesses low risk of contamination. The average metal contents in sediment and river water are consistently lower than the literature values reported and well below the limit of various guidelines. For fishes, trace element Hg was detected; however, the concentration was below the permissible level suggested by the Food and Agriculture Organization.

Distribution of Major and Trace Elements in a Tropical Hydroelectric Reservoir in Sarawak, Malaysia

PubMed Central

Nyanti, Lee; Ean Lee, Terri Zhuan; Mohd Irwan Lu, Nurul Aida Lu

2014-01-01

This paper reports the metals content in water, sediment, macroalgae, aquatic plant, and fish of Batang Ai Hydroelectric Reservoir in Sarawak, Malaysia. The samples were acid digested and subjected to atomic absorption spectrometry analysis for Na, K, Mn, Cr, Ni, Zn, Mg, Fe, Sn, Al, Ca, As, Se, and Hg. The total Hg content was analysed on the mercury analyser. Results showed that metals in water, sediment, macroalgae, aquatic plant, and fish are distinguishable, with sediment and biota samples more susceptible to metal accumulation. The distributions of heavy metals in water specifically Se, Sn, and As could have associated with the input of fish feed, boating, and construction activities. The accumulation of heavy metals in sediment, macroalgae, and aquatic plant on the other hand might be largely influenced by the redox conditions in the aquatic environment. According to the contamination factor and the geoaccumulation index, sediment in Batang Ai Reservoir possesses low risk of contamination. The average metal contents in sediment and river water are consistently lower than the literature values reported and well below the limit of various guidelines. For fishes, trace element Hg was detected; however, the concentration was below the permissible level suggested by the Food and Agriculture Organization. PMID:27437493

Profiling extractable and leachable inorganic impurities in ophthalmic drug containers by ICP-MS.

PubMed

Solomon, Paige; Nelson, Jenny

2018-03-01

In this study, we investigated the elemental impurities present in the plastic material of ophthalmic eye drop bottles using inductively coupled plasma-mass spectrometry (ICP-MS). Metallic contaminations, especially localized within the small cavity of the eye, can significantly perturb the ocular metallome. The concern is two-fold: first certain elements, for example heavy metals, can be toxic to humans at even trace levels, and second, these contaminations can have adverse reactions with other medicines or enzymatic processes in the eye. The implication of redox-active metals in cataract formation is one such biological consequence. The analysis demonstrated the effect of aggressive storage and transportation conditions on elemental extractable and leachable contamination, and posits that release of these elemental impurities can disrupt metallome equilibrium in the ocular compartment, leading to toxicity and disease.

Impact of tannery effluents on the aquatic environment of the Buriganga River in Dhaka, Bangladesh.

PubMed

Asaduzzaman, Mohammad; Hasan, Imtiaj; Rajia, Sultana; Khan, Nazneen; Kabir, Kazi Ahmed

2016-06-01

This study presents an overview of the existence and effects of six heavy metals, chromium (Cr), lead (Pb), cadmium (Cd), mercury (Hg), manganese (Mn), and aluminum (Al), in tannery effluents released to the Buriganga River in Dhaka, Bangladesh. The pollutants were found in three different sources, such as effluents from tanneries, contaminated river water and three species of fish-climbing perch (Anabas testudineus), spotted snakehead (Channa punctata), and Black tilapia (Oreochromis mossambicus) caught from the river. Tannery effluents, water, and fish samples were collected from three different factories, five sample stations, and three different harvesting points, respectively. Effluents from all three factories contained significant amounts of heavy metals, especially Cr (374.19 ppm in average), whereas lesser amounts were found in the tissues of the three fish species studied. The trends in tissue elemental concentrations of fish were Cr > Pb > Al > Hg > Mn > Cd. In most cases (Cr, Cd, Mn, and Al), heavy metal concentrations were found to be greater in climbing perch than in Black tilapia and spotted snakehead. Although the river water contained high concentrations of harmful heavy metals, the fish species under study had concentrations well below the permissible Food and Agriculture Organization/World Health Organization levels for those metals and seemed to be safe for human consumption. © The Author(s) 2014.

Risk Assessment and Implication of Human Exposure to Road Dust Heavy Metals in Jeddah, Saudi Arabia

PubMed Central

Shabbaj, Ibrahim I.; Alghamdi, Mansour A.; Shamy, Magdy; Alsharif, Musaab M.; Khoder, Mamdouh I.

2017-01-01

Data dealing with the assessment of heavy metal pollution in road dusts in Jeddah, Saudi Arabia and its implication to human health risk of human exposure to heavy metals, are scarce. Road dusts were collected from five different functional areas (traffic areas (TA), parking areas (PA), residential areas (RA), mixed residential commercial areas (MCRA) and suburban areas (SA)) in Jeddah and one in a rural area (RUA) in Hada Al Sham. We aimed to measure the pollution levels of heavy metals and estimate their health risk of human exposure applying risk assessment models described by United States Environmental Protection Agency (USEPA). Using geo-accumulation index (Igeo), the pollution level of heavy metals in urban road dusts was in the following order Cd > As > Pb > Zn > Cu > Ni > Cr > V > Mn > Co > Fe. Urban road dust was found to be moderately to heavily contaminated with As, Pb and Zn, and heavily to extremely contaminated with Cd. Calculation of enrichment factor (EF) revealed that heavy metals in TA had the highest values compared to that of the other functional areas. Cd, As, Pb, Zn and Cu were severely enriched, while Mn, V, Co, Ni and Cr were moderately enriched. Fe was considered as a natural element and consequently excluded. The concentrations of heavy metals in road dusts of functional areas were in the following order: TA > PA > MCRA > SA > RA > RUA. The study revealed that both children and adults in all studied areas having health quotient (HQ) < 1 are at negligible non-carcinogenic risk. The only exception was for children exposed to As in TA. They had an ingestion health quotient (HQing) 1.18 and a health index (HI) 1.19. The most prominent exposure route was ingestion. The cancer risk for children and adults from exposure to Pb, Cd, Co, Ni, and Cr was found to be negligible (≤1 × 10−6). PMID:29278373

Contamination source apportionment and health risk assessment of heavy metals in soil around municipal solid waste incinerator: A case study in North China.

PubMed

Ma, Wenchao; Tai, Lingyu; Qiao, Zhi; Zhong, Lei; Wang, Zhen; Fu, Kaixuan; Chen, Guanyi

2018-08-01

Few studies have comprehensively taken into account the source apportionment and human health risk of soil heavy metals in the vicinity of municipal solid waste incinerator (MSWI) in high population density area. In this study, 8 elements (Cr, Pb, Cu, Ni, Zn, Cd, Hg, and As) in fly ash, soil samples from different functional areas and vegetables collected surrounding the MSWI in North China were determined. The single pollution index, integrated Nemerow pollution index, principal component analysis (PCA), absolute principle component score-multiple linear regression (APCS-MLR) model and dose-response model were used in this study. The results showed that the soils around the MSWI were moderately polluted by Cu, Pb, Zn, and Hg, and heavily polluted by As and Cd. MSWI had a significant influence on the distribution of soil heavy metals in different distances from MSWI. The source apportionment results showed that MSWI, natural source, industrial discharges and coal combustion were the four major potential sources for heavy metals in the soils, with the contributions of 36.08%, 29.57%, 10.07%, and 4.55%, respectively. MSWI had a major impact on Zn, Cu, Pb, Cd, and Hg contamination in soil. The non-carcinogenic risk and carcinogenic risk posed by soil heavy metals surrounding the MSWI were unacceptable. The soil heavy metals concentrations and health risks in different functional areas were distinct. MSWI was the predominate source of non-carcinogenic risk with the average contribution rate of 36.99% and carcinogenic risk to adult male, adult female and children with 4.23×10 -4 , 4.57×10 -4 , and 1.41×10 -4 respectively, implying that the impact of MSWI on human health was apparent. This study provided a new insight for the source apportionment and health risk assessment of soil heavy metals in the vicinity of MSWI. Copyright © 2018. Published by Elsevier B.V.

Relationship between heavy metal accumulation and morphometric parameters in European hare (Lepus europaeus) inhabiting various types of landscapes in southern Poland.

PubMed

Wajdzik, Marek; Halecki, Wiktor; Kalarus, Konrad; Gąsiorek, Michał; Pająk, Marek

2017-11-01

To evaluate the influence of hazardous substances in the environment, studies of pollutant accumulation in wild living animals are needed. Studies dealing with heavy metal contamination in mammals usually focus on a single organ. We investigated accumulation of heavy metals as well as iron in European hare (Lepus europaeus) living in southern Poland, Małopolska Province. Hares were captured during the hunting season. We tested metal accumulation in 14 organs and tissues using 35 individuals with known body weight and sex inhabiting agricultural, industrial and other types of landscapes. To obtain deeper insight into contamination patterns, we used accumulation data from the liver since it is the most frequently investigated organ and prone to pollution accumulation. Based on the data obtained for the liver, we tested the impact of metal pollution on hare morphology, including body length and several skull cranimetric parameters. Metals content differed between organs. Moreover, individuals from industrial areas had higher Cd content in their body. We distinguished two groups of elements: the first group, Cd, Fe and Zn, revealed the highest toxic effect in the liver and kidneys; the second group, Cr, Ni, and Pb, accumulated primarily in the brain. Hares inhabiting industrial areas had higher concentration of Cd and Pb, and lower levels of Cr and Fe in their liver in comparison with those from agricultural and forest habitats. Heavy metals had an effect on body length that was negatively associated with Cr levels. Skull diastema length was associated positively with accumulation of Cd and Pb. We showed that hare organs and tissues could be used as bioindicators of environmental pollution by heavy metals. Copyright © 2017 Elsevier Inc. All rights reserved.

Implications of metal accumulation mechanisms to phytoremediation.

PubMed

Memon, Abdul R; Schröder, Peter

2009-03-01

Trace elements (heavy metals and metalloids) are important environmental pollutants, and many of them are toxic even at very low concentrations. Pollution of the biosphere with trace elements has accelerated dramatically since the Industrial Revolution. Primary sources are the burning of fossil fuels, mining and smelting of metalliferous ores, municipal wastes, agrochemicals, and sewage. In addition, natural mineral deposits containing particularly large quantities of heavy metals are found in many regions. These areas often support characteristic plant species thriving in metal-enriched environments. Whereas many species avoid the uptake of heavy metals from these soils, some of them can accumulate significantly high concentrations of toxic metals, to levels which by far exceed the soil levels. The natural phenomenon of heavy metal tolerance has enhanced the interest of plant ecologists, plant physiologists, and plant biologists to investigate the physiology and genetics of metal tolerance in specialized hyperaccumulator plants such as Arabidopsis halleri and Thlaspi caerulescens. In this review, we describe recent advances in understanding the genetic and molecular basis of metal tolerance in plants with special reference to transcriptomics of heavy metal accumulator plants and the identification of functional genes implied in tolerance and detoxification. Plants are susceptible to heavy metal toxicity and respond to avoid detrimental effects in a variety of different ways. The toxic dose depends on the type of ion, ion concentration, plant species, and stage of plant growth. Tolerance to metals is based on multiple mechanisms such as cell wall binding, active transport of ions into the vacuole, and formation of complexes with organic acids or peptides. One of the most important mechanisms for metal detoxification in plants appears to be chelation of metals by low-molecular-weight proteins such as metallothioneins and peptide ligands, the phytochelatins. For example, glutathione (GSH), a precursor of phytochelatin synthesis, plays a key role not only in metal detoxification but also in protecting plant cells from other environmental stresses including intrinsic oxidative stress reactions. In the last decade, tremendous developments in molecular biology and success of genomics have highly encouraged studies in molecular genetics, mainly transcriptomics, to identify functional genes implied in metal tolerance in plants, largely belonging to the metal homeostasis network. Analyzing the genetics of metal accumulation in these accumulator plants has been greatly enhanced through the wealth of tools and the resources developed for the study of the model plant Arabidopsis thaliana such as transcript profiling platforms, protein and metabolite profiling, tools depending on RNA interference (RNAi), and collections of insertion line mutants. To understand the genetics of metal accumulation and adaptation, the vast arsenal of resources developed in A. thaliana could be extended to one of its closest relatives that display the highest level of adaptation to high metal environments such as A. halleri and T. caerulescens. This review paper deals with the mechanisms of heavy metal accumulation and tolerance in plants. Detailed information has been provided for metal transporters, metal chelation, and oxidative stress in metal-tolerant plants. Advances in phytoremediation technologies and the importance of metal accumulator plants and strategies for exploring these immense and valuable genetic and biological resources for phytoremediation are discussed. A number of species within the Brassicaceae family have been identified as metal accumulators. To understand fully the genetics of metal accumulation, the vast genetic resources developed in A. thaliana must be extended to other metal accumulator species that display traits absent in this model species. A. thaliana microarray chips could be used to identify differentially expressed genes in metal accumulator plants in Brassicaceae. The integration of resources obtained from model and wild species of the Brassicaceae family will be of utmost importance, bringing most of the diverse fields of plant biology together such as functional genomics, population genetics, phylogenetics, and ecology. Further development of phytoremediation requires an integrated multidisciplinary research effort that combines plant biology, genetic engineering, soil chemistry, soil microbiology, as well as agricultural and environmental engineering.

Microplastics in the surface sediments from the Beijiang River littoral zone: Composition, abundance, surface textures and interaction with heavy metals.

PubMed

Wang, Jundong; Peng, Jinping; Tan, Zhi; Gao, Yifan; Zhan, Zhiwei; Chen, Qiuqiang; Cai, Liqi

2017-03-01

While large quantities of studies on microplastics in the marine environment have been widely carried out, few were available in the freshwater environment. The occurrence and characteristics, including composition, abundance, surface texture and interaction with heavy metals, of microplastics in the surface sediments from Beijiang River littoral zone were investigated. The concentrations of microplastics ranged from 178 ± 69 to 544 ± 107 items/kg sediment. SEM images illustrated that pits, fractures, flakes and adhering particles were the common patterns of degradation. Chemical weathering of microplastics was also observed and confirmed by μ-FTIR. EDS spectra displayed difference in the elemental types of metals on the different surface sites of individual microplastic, indicating that some metals carried by microplastics were not inherent but were derived from the environment. The content of metals (Ni, Cd, Pb, Cu, Zn and Ti) in microplastics after ultrasonic cleaning has been analyzed by ICP-MS. Based on data from the long-term sorption of metals by microplastics and a comparison of metal burden between microplastics, macroplastics and fresh plastic products, we suggested that the majority of heavy metals carried by microplastics were derived from inherent load. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling of Thermochemical Behavior in an Industrial-Scale Rotary Hearth Furnace for Metallurgical Dust Recycling

NASA Astrophysics Data System (ADS)

Wu, Yu-Liang; Jiang, Ze-Yi; Zhang, Xin-Xin; Xue, Qing-Guo; Yu, Ai-Bing; Shen, Yan-Song

2017-10-01

Metallurgical dusts can be recycled through direct reduction in rotary hearth furnaces (RHFs) via addition into carbon-based composite pellets. While iron in the dust is recycled, several heavy and alkali metal elements harmful for blast furnace operation, including Zn, Pb, K, and Na, can also be separated and then recycled. However, there is a lack of understanding on thermochemical behavior related to direct reduction in an industrial-scale RHF, especially removal behavior of Zn, Pb, K, and Na, leading to technical issues in industrial practice. In this work, an integrated model of the direct reduction process in an industrial-scale RHF is described. The integrated model includes three mathematical submodels and one physical model, specifically, a three-dimensional (3-D) CFD model of gas flow and heat transfer in an RHF chamber, a one-dimensional (1-D) CFD model of direct reduction inside a pellet, an energy/mass equilibrium model, and a reduction physical experiment using a Si-Mo furnace. The model is validated by comparing the simulation results with measurements in terms of furnace temperature, furnace pressure, and pellet indexes. The model is then used for describing in-furnace phenomena and pellet behavior in terms of heat transfer, direct reduction, and removal of a range of heavy and alkali metal elements under industrial-scale RHF conditions. The results show that the furnace temperature in the preheating section should be kept at a higher level in an industrial-scale RHF compared with that in a pilot-scale RHF. The removal rates of heavy and alkali metal elements inside the composite pellet are all faster than iron metallization, specifically in the order of Pb, Zn, K, and Na.

Heavy metal distribution and partitioning in the vicinity of the discharge areas of Lisbon drainage basins (Tagus Estuary, Portugal)

NASA Astrophysics Data System (ADS)

Duarte, Bernardo; Silva, Gilda; Costa, José Lino; Medeiros, João Paulo; Azeda, Carla; Sá, Erica; Metelo, Inês; Costa, Maria José; Caçador, Isabel

2014-10-01

Worldwide estuarine ecosystems are by their privileged geographic location, anthropogenically impacted systems. Heavy metal contamination in estuarine waters and sediments are well known to be one of the most important outcomes driven from human activities. The partitioning of these elements has been widely focused, due to its importance not only on the estuarine biogeochemistry but also on its bioavailability to the trophic webs. As observed in other estuaries, in the Tagus basin, no increase in the partition coefficients with the increasing suspended particulate matter concentrations was observed, mostly due to a permanent dilution process of the suspended matter, rich in heavy metals and less contaminated and resuspended bottom sediments. Another important outcome of this study was the common origin of all the analysed heavy metals, probably due to the large industrialization process that the margins of the Tagus estuary suffered in the past, although no relationship was found with the presence of the different discharge areas. In fact, metal partitioning seems to be mostly influenced by the chemical species in which the pollutant is delivered to the system and on water chemistry, with a higher emphasis on the metal cycling essentially between the particulate and dissolved phase. This partitioning system acquires a relevant importance while evaluating the impacts of marine construction and the associated dredging operations, and consequent changes in the estuarine water chemistry.

Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash

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

Kuboňová, L., E-mail: lenka.kubonova@vsb.cz; Langová, Š.; Nowak, B.

2013-11-15

Highlights: • MSW fly ash was thermally and hydrometallurgically treated to remove heavy metals. • More than 90% of easy volatile heavy metals (Cd and Pb) were removed thermally. • More than 90% of Cd, Cr, Cu an Zn were removed by alkaline – acid leaching. • The best results were obtained for the solution of 3 M NaOH and 2 M H{sub 2}SO{sub 4}. - Abstract: Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be amore » potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel.« less

[Accumulation, distribution and pollution assessment of heavy metals in surface sediment of Caohai plateau wetland, Guizhou province].

PubMed

Zhang, Qing-Hai; Lin, Chang-Hu; Tan, Hong; Lin, Shao-Xia; Yang, Hong-Bo

2013-03-01

The objective of this paper is to investigate the concentrations and distribution characteristics of heavy metals in surface sediments of different areas in the Caohai plateau wetland. 16 samples of surface sediments were collected and 7 heavy metals were analyzed. Heavy metal pollution in surface sediments of different areas in the Caohai plateau wetland was estimated by the Tomlinson Pollution Load Index (PLI) method. The analyzed results indicated that the average contents of Cd, Hg, As, Pb, Cr, Cu, Zn were 0.985, 0.345, 15.8, 38.9, 38.6, 22.8 and 384 mg x kg(-1), respectively. The heavy metal distributions varied with regional environment changes, the order of average contents of Cd and Hg in different regions was E (the eastern region) > S (the southern region) > N (the northern region), the order of the average content of Pb was N > E > S, and that of Zn was S > E > N. The results also suggested a medium heavy metal pollution level in the surface sediment of the Caohai plateau wetland with the PLI(zone) reaching 1.17. The order of pollution level in surface sediments of different regions was E > S > N. The results showed medium pollution levels in E and Hg which reached the extreme intensity pollution level were also the major polluted elements in surface sediments of the Caohai plateau wetland. And also, results showed medium pollution levels of Cd and Pb in surface sediments of Caohai plateau wetland. Cluster analysis results showed similar pollution sources of Cd, Zn, Pb and Hg, which should be attached great importance in terms of the prevention of the Caohai plateau wetland.

Chemometric evaluation of heavy metal pollutions in Patna region of the Ganges alluvial plain, India: implication for source apportionment and health risk assessment.

PubMed

Devi, Ningombam Linthoingambi; Yadav, Ishwar Chandra

2018-03-28

While metal pollution and distribution in soil are well documented for many countries, the situation is more serious in developing countries because of the rapid increase in industrialization and urbanization during last decades. Although it is well documented in developed countries, data about substantial metal pollution in Indian soil, especially in eastern Ganges alluvial plain (GAP), are limited. In this study, eight different blocks of Patna district located in eastern GAP were selected to investigate the contamination, accumulation, and sources of metals in surface soil considering different land use types. Additionally, human health risk assessment was estimated to mark the potential carcinogenic and non-carcinogenic effect of metals in soil. The concentration of all metals (except Pb) in soil was below the Indian standard limit of the potential toxic element for agricultural soil. Pb was the most abundant in soil, followed by Zn and Cu, and accounted for 52, 33 and 8% of the total metal. In terms of land use types, roadside soil detected higher concentrations of all metals, followed by park/grassland soil. Principal component analysis results indicated traffic pollution and industrial emissions are the major sources of heavy metals in soil. This was further confirmed by strong inter-correlation of heavy metals (Cd, Cr, Ni, Cu and Pb). Human health risk assessment results indicated ingestion via soil as the primary pathway of heavy metal exposure to both adults and children population. The estimated hazard index was highest for Pb, suggesting significant non-carcinogenic effect to both adults and children population. The children were more prone to the non-carcinogenic effect of Pb than adults. However, relatively low cancer risk value estimated for all metals suggested non-significant carcinogenic risk in the soil.

Uptake of heavy metals and arsenic in black soldier fly (Hermetia illucens) larvae grown on seaweed-enriched media.

PubMed

Biancarosa, Irene; Liland, Nina S; Biemans, Daan; Araujo, Pedro; Bruckner, Christian G; Waagbø, Rune; Torstensen, Bente E; Lock, Erik-Jan; Amlund, Heidi

2018-04-01

The black soldier fly (Hermetia illucens) is one of the most promising insect species for use in animal feed. However, studies investigating feed and food safety aspects of using black soldier fly as feed are scarce. In this study, we fed black soldier fly larvae feeding media enriched with seaweed, which contains naturally high concentrations of heavy metals and arsenic. The aim of this study was to investigate the potential transfer of such undesirable substances from the feeding media to the larvae. The larvae accumulated cadmium, lead, mercury and arsenic. Concentrations of these elements in the larvae increased when more seaweed was added to the feeding media. The highest retention was seen for cadmium (up to 93%) and the lowest for total arsenic (up to 22%). When seaweed inclusion exceeded 20% in the media, this resulted in larval concentrations of cadmium and total arsenic above the current European Union maximum levels for these elements in complete feed. Our results confirm that insect larvae can accumulate heavy metals and arsenic when present in the feeding media. A broader understanding of the occurrence of these undesirable substances in processed larvae products is needed to assess feed and food safety. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Environmental geochemistry of a highly polluted area: the Mazarambroz Pb-Zn mine (Castilla-La Mancha region, Spain)

NASA Astrophysics Data System (ADS)

González-Corrochano, Beatriz; Higueras, Pablo; Jurado, Verónica; María Esbrí, José; Martínez-Coronado, Alba; Alonso-Azcárate, Jacinto

2013-04-01

Human activities, as mining, can alter the concentrations of metals in the environmental compartments and facilitate their dispersion (Moreno Grau, 2003). Total concentrations are usually evaluated, but they do not provide information about the bioavailability and toxicity of metals, since changes in the environmental conditions cause selective release of the total metal content (Sahuquillo et al., 2003). Thus, the bioavailability or toxic effects of the metals can only be studied by determining their chemical partitioning (Quevauviller, 1998). Leaching by selective chemical extracts is the conventional method for evaluating the availability of elements. The Mazarambroz Pb-Zn mine, located in the Castilla-La Mancha region (central Spain), is an important case of abandoned Pb-Zn sulphide mine, with high concentrations of other highly toxic heavy metals such as Cu, As and Cd. The objectives of this work were to determine the extent of the heavy metal contamination and to study the heavy metal bioavailability, by the application of selective chemical extractions, in the Mazarambroz mine area. Soil and sediment samples were taken from the studied area according to a systematic sampling type (regular grid). Soil main parameters (reactivity and conductivity) were determined. Chemical extractions were made using two different selective reagents: i) CaCl2 (0.01M) (Novozamsky et al., 1993) and; ii) EDTA (0.05 M) (Quevauviller, 1996). The contents of heavy metals in the extracts were measured by inductively coupled plasma-mass spectroscopy (ICP-MS). The compounds extracted with the CaCl2 solution represent the water soluble and exchangeable fractions, so they can be considered as the metal concentration that can be absorbed by plants. EDTA solution extracts metals on exchange sites of both inorganic and organic complexes. Additionally, it can dissolve calcareous materials through complexation of calcium and magnesium (Chao, 1984; Sahuquillo et al., 2003). Total geochemical analyses of the samples were carried out using a Field Portable X-Ray Fluorescence Spectroscopy analyser (EDXRF). Results were statistically processed with Minitab 15.0 and mapped with Surfer 9. The mean concentrations of the studied heavy metals are significantly higher than the world average, the Castilla-La Mancha region mean and the local reference value for soils, so the studied area can be considered a polluted area as consequence of the mining process carried out in the Mazarambroz Pb-Zn mine. The total affected area by high concentrations of heavy metals differs depending on the studied element, reaching the maximum extension and importance for lead and zinc. In the studied area, soil and sediments are also affected by very low pH and high conductivity, which indicates the presence of soluble salts, likely sulfates, products of the sulfide oxidation. These results would imply an increase in the heavy metal mobility and transference to the plants and, as a consequence, an increase in the environmental damage since the area close to the mine is used for the cultivation of cereals and rabbit hutting. The results of the extractions show that the highest extracted concentrations are obtained from the sediment samples due to the influence of the stream in the weathering of this type of materials. References - Chao, T.T., 1984. Use of partial dissolution techniques in geochemical exploration. Journal of Geochemical Exploration, 20, 101-135. - Moreno Grau, M.D., 2003. Environmental Toxicology: Risk Assessment to Human Health. Mc Graw Hill, Madrid. - Novozamsky, I., Lexmond, T.M., Houba, V.J.G., 1993. A single extraction procedure of soil for evaluation of uptake f some heavy metals by plants. International Journal of Environmental Analytical Chemistry, 51, 47-58. - Quevauviller, P., Lachica, M., Barahona, E., Rauret, G., Ure, A., Gomez, A., Muntau, H., 1996. Interlaboratory comparison of EDTA and DTPA procedures prior to certification of extractable trace elements in calcareous soil. Science of the Total Environment, 178, 137-132. - Quevauviller, Ph., 1998. Operationally defined extraction procedures for soil and sediment analysis I. Standardization. Trac-Trends in Analytical Chemistry, 17 (5), 289-298. - Sahuquillo, A., Rigol, A., Rauret, G., 2003. Overview of the use of leaching/extraction tests for risk assessment of trace metals in contaminated soils and sediments. Trac-Trends in Analytical Chemistry, 22 (3), 152-159.

Assessment of heavy metals (Cd and Pb) and micronutrients (Cu, Mn, and Zn) of paddy (Oryza sativa L.) field surface soil and water in a predominantly paddy-cultivated area at Puducherry (Pondicherry, India), and effects of the agricultural runoff on the elemental concentrations of a receiving rivulet.

PubMed

Reddy, M Vikram; Satpathy, Deepmala; Dhiviya, K Shyamala

2013-08-01

The concentrations of toxic heavy metals-Cd and Pb and micronutrients-Cu, Mn, and Zn were assessed in the surface soil and water of three different stages of paddy (Oryza sativa L.) fields, the stage I-the first stage in the field soon after transplantation of the paddy seedlings, holding adequate amount of water on soil surface, stage II-the middle stage with paddy plants of stem of about 40 cm length, with sufficient amount of water on the soil surface, and stage III-the final stage with fully grown rice plants and very little amount of water in the field at Bahour, a predominantly paddy cultivating area in Puducherry located on the southeast Coast of India. Comparison of the heavy metal and micronutrient concentrations of the soil and water across the three stages of paddy field showed their concentrations were significantly higher in soil compared with that of water (p < 0.05) of the fields probably because of accumulation and adsorption in soil. The elemental concentrations in paddy soil as well as water was in the ranking order of Cd > Mn > Zn > Cu > Pb indicating concentration of Cd was maximum and Pb was minimum. The elemental concentrations in both soil and water across the three stages showed a ranking order of stage II > stage III > stage I. The runoff from the paddy fields has affected the elemental concentrations of the water and sediment of an adjacent receiving rivulet.

PM2.5 levels, chemical composition and health risk assessment in Xinxiang, a seriously air-polluted city in North China.

PubMed

Feng, Jinglan; Yu, Hao; Liu, Shuhui; Su, Xianfa; Li, Yi; Pan, Yuepeng; Sun, Jianhui

2017-10-01

Seventeen PM 2.5 samples were collected at Xinxiang during winter in 2014. Nine water-soluble ions, 19 trace elements and eight fractions of carbonaceous species in PM 2.5 were analyzed. PM 2.5 concentrations and elements species during different periods with different pollution situations were compared. The threat of heavy metals in PM 2.5 was assessed using incremental lifetime cancer risk. During the whole period, serious regional haze pollution persisted, and the averaged concentration of PM 2.5 was 168.5 μg m -3 , with 88.2 % of the daily samples exhibiting higher PM 2.5 concentrations than the national air quality standard II. The high NO 3 - /SO 4 2- ratio suggested that vehicular exhaust made an important contribution to atmospheric pollution. All of organic carbon and elemental carbon ratios in this study were above 2.0 for PM 2.5 , which might reflect the combined contributions from coal combustion, motor vehicle exhaust and biomass burning. Mean 96-h backward trajectory clusters indicated that more serious air pollution occurred when air masses transported from the Hebei, Shanxi and Zhengzhou. The concentrations of the water-soluble ions and trace elements on haze days were 2 and 1.8 times of those on clear days. The heavy metals in PM 2.5 might not cause non-cancerous health issues by exposure through the human respiratory system. However, lifetime cancer risks of heavy metals obviously exceeded the threshold (10 -6 ) and might have a cancer risk for residents in Xinxiang. This study provided detailed composition data and comprehensive analysis of PM 2.5 during the serious haze pollution period and their potential impact on human health in Xinxiang.

Metal and transuranic records in mussel shells, byssal threads and tissues

NASA Astrophysics Data System (ADS)

Koide, Minoru; Lee, Dong Soo; Goldberg, Edward D.

1982-12-01

Bivalve shells offer several advantages over tissues for the monitoring of heavy metal pollutants in the marine environment. They are easier to handle and to store. The problem of whether to depurate the animals before analyses is avoided. The shells appear to be more sensitive to environmental heavy metals levels over the long term than do the soft parts. Of the substances examined (Cd, Cu, Zn, Pb, Ag, Ni, 238Pu and 239 + 240Pu) only Pb and Pu displayed a strong covariance between soft tissue and shell concentrations. There were strong correlations between metals in the shell but not in the soft tissues in general. The byssal threads, because of their enrichment of transuranic elements and of their ease in handling, may be useful in monitoring these metals. A very weak discharge of 238Pu to marine waters adjacent to a nuclear reactor was detected in the byssal threads of mussels.

Determining the metallicity of the solar envelope using seismic inversion techniques

NASA Astrophysics Data System (ADS)

Buldgen, G.; Salmon, S. J. A. J.; Noels, A.; Scuflaire, R.; Dupret, M. A.; Reese, D. R.

2017-11-01

The solar metallicity issue is a long-lasting problem of astrophysics, impacting multiple fields and still subject to debate and uncertainties. While spectroscopy has mostly been used to determine the solar heavy elements abundance, helioseismologists attempted providing a seismic determination of the metallicity in the solar convective envelope. However, the puzzle remains since two independent groups provided two radically different values for this crucial astrophysical parameter. We aim at providing an independent seismic measurement of the solar metallicity in the convective envelope. Our main goal is to help provide new information to break the current stalemate amongst seismic determinations of the solar heavy element abundance. We start by presenting the kernels, the inversion technique and the target function of the inversion we have developed. We then test our approach in multiple hare-and-hounds exercises to assess its reliability and accuracy. We then apply our technique to solar data using calibrated solar models and determine an interval of seismic measurements for the solar metallicity. We show that our inversion can indeed be used to estimate the solar metallicity thanks to our hare-and-hounds exercises. However, we also show that further dependencies in the physical ingredients of solar models lead to a low accuracy. Nevertheless, using various physical ingredients for our solar models, we determine metallicity values between 0.008 and 0.014.

Development of a heavy metal sorption system through the P=S functionalization of coconut (Cocos nucifera) fibers.

PubMed

de Sousa, Dayane Almeida; de Oliveira, Elisabeth; da Costa Nogueira, Márcio; Espósito, Breno Pannia

2010-01-01

Lignocellulosic residues are interesting materials for the production of heavy metal adsorbents for aquatic systems. Whole fibers taken from coconut (Cocos nucifera) husks were functionalized with the thiophosphoryl (P=S) group by means of the direct reaction with Cl(3)PS, (CH(3)O)(2)ClP=S or (CH(3)CH(2)O)(2)ClP=S in order to obtain an adsorptive system for 'soft' metal ions, particularly Cd(2+). These functionalized fibers (FFs) were characterized by means of elemental analysis, infrared spectroscopy, thermal analysis and acid-base titration. Adsorption isotherms for Cd(2+) fitted the Langmuir model, with binding capacities of 0.2-5 m mol g(-1) of FF at 25 degrees C.

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.

Selective Separation and Determination of Heavy Metals (Cd, Pb, Cr) Speciation Forms from Hortic Antrosols

NASA Astrophysics Data System (ADS)

Bulgariu, D.; Bulgariu, L.

2009-04-01

The speciation, inter-phases distribution and biodisponibility of heavy metals in soils represent one of main problem of environmental geochemistry and agro-chemistry. This problem is very important in case of hortic antrosols (soils from glasshouses) for the elimination of agricultural products (fruits, vegetables) contamination with heavy metals. In soils from glass houses, the speciation and inter-phases distribution processes of heavy metals have a particular dynamic, different in comparison with those from non-protected soils. The predominant distribution forms of heavy metals in such soils types are: complexes with low mass organic molecules, organic-mineral complexes, complexes with inorganic ligands (hydroxide-complexes, carbonate-complexes, sulphate-complexes, etc.) and basic salts. All of these have high stabilities in conditions of soils from glass houses, and in consequence, the separation and determination of speciation forms (which is directly connected with biodisponibility of heavy metals) by usual methods id very difficult and has a high uncertain degree. In this study is presented an original method for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils, which is based by the combination of solid-liquid sequential extraction (SPE) with the extraction in aqueous polymer-inorganic salt two-phase systems (ABS). The soil samples used for this study have been sampled from three different locations (glass houses from Iasi, Barlad and Bacau - Romania) where the vegetables cultivation have bee performed by three different technologies. In this way was estimated the applicability and the analytical limits of method proposed by as, in function of the chemical-mineralogical and physical-chemical characteristics of soils. As heavy metals have been studied cadmium, lead and chromium, all being known for their high toxicity. The procedure used for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils has two main steps: (i) non-destructive separation of chemical-mineralogical associations and aggregates from soils samples - for this the separation method with heavy liquids (bromophorme) and isodynamic magnetic method have been used; (ii) sequential extraction of heavy metals from soil fractions separated in the first step, by using combined SPE-ABS procedure. For the preparation of combined extraction systems was used polyethylene glycol (with different molecular mass: 2000, 4000 and 8000). As phase-forming inorganic salts and as selective extracting agents we have used different usual inorganic reagents. The type and concentration of phase-forming salts have been selected in function of, both nature of extracted heavy metals and chemical-mineralogical characteristics of soil samples. The experimental parameters investigated in this study are: molecular mass of polyethylene glycol and the concentration of polymeric solutions, nature and concentration of phase-forming salts, nature and concentration of extracting agents, pH in extraction system phase, type of extracted heavy metals, type of speciation forms of heavy metals and their concentrations. All these factors can influence significantly the efficiency and the selectivity of separation process. The experimental results have indicate that the combined SPE-ABS extraction systems have better separation efficiency, in comparison with traditional SPE systems and ca realized a accurate discrimination between speciation forms of heavy metals from soils. Under these conditions, the estimation of inter-phases distribution and biodisponibility of heavy metals has a high precision. On the other hand, when the combined SPE-ABS systems are used, the concomitant extraction of the elements from the same geochemical association with studied heavy metals (inevitable phenomena in case of separation by SPE procedures) is significant diminished. This increases the separation selectivity and facilitated the more accurate determination of speciation forms concentration. By adequate selection of extraction conditions can be realized the selective separation of organic-mineral complexes, which will permit to perform detailed studies about the structure and chemical composition of these. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07).

Occurrence and distribution of selected heavy metals in the surface sediments of South Brittany coastal waters: An assessment using pollution indicators

NASA Astrophysics Data System (ADS)

Ong, M. C.; Menier, D.; Noor Azhar, M. S.; Dupont, V.; Révillon, S.

2012-04-01

In order to avoid the pollution of heavy metals in South Brittany water, it is necessary to establish the data and understand the mechanisms influencing the distribution of heavy metals of the area. One of the aims of this work was to assess heavy metals contamination in Gulf of Morbihan and Quiberon Bay. Another aim was to use interpolation surfaces per metals to assess the contamination separately per metal. A total of 196 bottom sediment samples were collected from the coastal waters in order to determine the spatial concentration of Cr, Mn, Co, Cu, Zn, Cd and Pb by Inductively Coupled Plasma Mass Spectrometry (ICPMS) after acid digestion. The average heavy metal concentrations are ranked as follows: Mn>Zn>Cr>Pb>Cu>Cu>Cd. In the gulf, metal enrichments observed compared to the bay environment may due river run-off from three major river (Auray, Le Marle and Novalo rivers) which carried municipal waste and maritime activities along the coastal area within the gulf. Beside those factors, the natural factors such as the sheltered basin morphology itself, fine sediment and low hydrodynamic regime which favour the in situ accumulation of pollutants. The level of pollution levels attributed to heavy metals was evaluated using several pollution indicators in order to determine anthropogenically derived sediment contamination. Comparison to sediment quality guidelines (SQGs), enrichment factors (EFs), index of geoaccumulation (Igeo) and contamination factors (CF) based on reference element and background value to compensate for the influence of the natural variability in sediment mineralogy and to assess whether the concentration observed in surface sediment represent background and contaminated levels and visualize using ArcGIS software. These analyses validated that the bottom sediment only enriched in Pb and the other metals in most sample are not due to artificial contamination. Overall, geochemistry of the samples show the effect of both natural and anthropogenic inputs to the catchment, however, natural processes are more dominant than anthropogenic inputs in concentrating metals in the sediment.

Heavy Metals Concentrations in top Soils of Urban Areas (Naples - Southern Italy) as an Indicator of Anthropogenic Origin.

NASA Astrophysics Data System (ADS)

Cicchella, D.; De Vivo, B.; Lima, A.; Somma, R.

2001-12-01

Heavy metals pollution, which mainly originates from automobile exhausts and industry, is a serious danger for human health. The source and extension of heavy metals pollution in the top soils has been studied extensively in the past 30 years. The role of the soil processes in accumulating or mobilising metals is very important in environmental science due to the central position of the soil in the hydrological cycle and ecosystem. Concentrations of heavy metals in top soils, collected in green areas and public parks in metropolitan Naples area have been determined to provide information on specific emission sources. In addition to toxic metals, such as Pb, As, Cd, Cr and others, we have investigated the top soils as well for Pt group elements (PGEs), because since 1993 it is mandatory within EC for all new petrol driven motor vehicles to be equipped with Pt/Pd/Rh catalytic converter. In Italy this law has come into effect in 1998, but still is allowed to old vehicles use lead gasoline, though now the big majority of cars is equipped with Pt/Pd/Rh catalytic converters. Emission of abraded fragments of catalytic converters in vehicle exhausts will certainly determine environmental contamination with Pt group elements (PGEs), since many Pt complexes are highly cytotoxic and, in small dose, are strong allergens and potent sensitiser. The metropolitan area of Naples due to intense human activities and vehicles traffic is an interesting area to be monitored in order to check the pollution state of the soils. The geology of the area is prevalently represented by volcanics, erupted from the Upper Pleistocene to Recent by Mt. Somma-Vesuvius on the east and the Campi Flegrei fields on the west. To compile multi-element geochemical maps baseline we have sampled in situ and transported top soil for a total of 200 samples. The survey have been carried at about 200 sites covering an area of about 120 Km2, with a grid of 0.5 x 0.5 km in the highly urbanised area and 1 km x 1 km in the sub urban areas. In each sampled site has been determined the pH (5.93- 8.21); and measured partial and total radioactivity (U, Th, K) using a portable scintillometer. All soil samples were analysed for 40 elements by ICP-MS and AES. The data for some of the harmful metals (as mg Kg-1) range as follows: Cd from 0.03 to 6.9, Cr from 0.8 to 189, Ni from 0.8 to 67, Pb from 17 to 2052, Co from 3 to 37, Hg from 0.01 to 2.6, Pt from 0.001 to 0.1, Pd from 0.002 to 0.052. The geochemical data, have been processed by means of GIS to compile geochemical single element distribution, R-mode factor analysis element associations and risk maps. The latter in particular, are useful to enhance areas potentially at risk for residential/recreational and commercial/industrial land use, following intervention criteria fixed by Italian

Critical review of heavy metal pollution of traffic area runoff: Occurrence, influencing factors, and partitioning.

PubMed

Huber, Maximilian; Welker, Antje; Helmreich, Brigitte

2016-01-15

A dataset of 294 monitored sites from six continents (Africa, Asia, Australia, Europe, North and South America) was compiled and evaluated to characterize the occurrence and fate of heavy metals in eight traffic area categories (parking lots, bridges, and three types each of both roads and highways). In addition, site-specific (fixed and climatic) and method-specific (related to sample collection, preparation, and analysis) factors that influence the results of the studies are summarized. These factors should be considered in site descriptions, conducting monitoring programs, and implementing a database for further research. Historical trends for Pb show a sharp decrease during recent decades, and the median total Pb concentrations of the 21st century for North America and Europe are approximately 15 μg/L. No historical trend is detected for Zn. Zn concentrations are very variable in traffic area runoff compared with other heavy metals because of its presence in galvanized structures and crumbs of car tire rubber. Heavy metal runoff concentrations of parking lots differ widely according to their use (e.g., employee, supermarket, rest areas for trucks). Bridge deck runoff can contain high Zn concentrations from safety fences and galvanizing elements. Roads with more than 5000 vehicles per day are often more polluted than highways because of other site-specific factors such as traffic signals. Four relevant heavy metals (Zn, Cu, Ni, and Cd) can occur in the dissolved phase. Knowledge of metal partitioning is important to optimize stormwater treatment strategies and prevent toxic effects to organisms in receiving waters. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of low-temperature transformation of mixtures of sewage sludge and plant materials on content, leachability and toxicity of heavy metals.

PubMed

Gondek, Krzysztof; Baran, Agnieszka; Kopeć, Michał

2014-12-01

The aim of the study was to determine the influence of the process of low-temperature transformation and the addition of plant material to sewage sludge diversifying the content of mobile forms of heavy metals and their ecotoxicity. The experimental design included: sewage sludge+rape straw, sewage sludge+wheat straw, sewage sludge+sawdust, sewage sludge+bark and sewage sludge with no addition. The mixtures were subjected to thermal transformation in a chamber furnace, under conditions without air. The procedure consisted of two stages: the first stage (130°C for 40 min) focused on drying the material, whereas in the second stage (200°C for 30 min) proper thermal transformation of materials took place. Thermal transformation of the materials, caused an increase in total contents of heavy metals in comparison to the material before transformation. From among elements, the cadmium content changed the most in materials after thermal transformation. As a result of thermal transformation, the content of water soluble form of the heavy metals decreased significantly in all the prepared mixtures. Low toxicity of the extracts from materials for Vibrio fischeri and Lepidium sativum was found in the research, regardless of transformation process. L. sativum showed higher sensitivity to heavy metals occurring in the studied extracts from materials than V. fischeri, evidence of which are the positive significant correlations between the content of metals and the inhibition of root growth of L. sativum. Copyright © 2014 Elsevier Ltd. All rights reserved.

Application of multivariate statistical analysis in the pollution and health risk of traffic-related heavy metals.

PubMed

Ebqa'ai, Mohammad; Ibrahim, Bashar

2017-12-01

This study aims to analyse the heavy metal pollutants in Jeddah, the second largest city in the Gulf Cooperation Council with a population exceeding 3.5 million, and many vehicles. Ninety-eight street dust samples were collected seasonally from the six major roads as well as the Jeddah Beach, and subsequently digested using modified Leeds Public Analyst method. The heavy metals (Fe, Zn, Mn, Cu, Cd, and Pb) were extracted from the ash using methyl isobutyl ketone as solvent extraction and eventually analysed by atomic absorption spectroscopy. Multivariate statistical techniques, principal component analysis (PCA), and hierarchical cluster analysis were applied to these data. Heavy metal concentrations were ranked according to the following descending order: Fe > Zn > Mn > Cu > Pb > Cd. In order to study the pollution and health risk from these heavy metals as well as estimating their effect on the environment, pollution indices, integrated pollution index, enrichment factor, daily dose average, hazard quotient, and hazard index were all analysed. The PCA showed high levels of Zn, Fe, and Cd in Al Kurnish road, while these elements were consistently detected on King Abdulaziz and Al Madina roads. The study indicates that high levels of Zn and Pb pollution were recorded for major roads in Jeddah. Six out of seven roads had high pollution indices. This study is the first step towards further investigations into current health problems in Jeddah, such as anaemia and asthma.

Water Quality in Surface Water: A Preliminary Assessment of Heavy Metal Contamination of the Mashavera River, Georgia

PubMed Central

Urushadze, Teo

2018-01-01

Water quality contamination by heavy metal pollution has severe effects on public health. In the Mashavera River Basin, an important agricultural area for the national food system in Georgia (e.g., vegetable, dairy and wine production), water contamination has multiple influences on the regional and country-wide health. With new industrial activities in the region, sediment extraction, and discharge of untreated wastewater into the river, its tributaries and irrigation canals, a comprehensive study of water quality was greatly needed. This study examined sediment and water samples from 17 sampling sites in the Mashavera River Basin during the high and low precipitation seasons. The results were characterized utilizing the Geo-accumulation Index (Igeo), Enrichment Factor (EF), Pollution Load index (PLI), Contamination Factor (CF) and Metal Index (MI). According to the CFs, Cu > Cd > Zn > Pb > Fe > Mn > Ni > Cr > Hg is the descending order for the content of all observed heavy metals in sediments collected in both seasons. Fe and As were additionally examined in water samples. Overall, As, Cd and Pb, all highly toxic elements, were found in high concentrations in downstream sample sites. According to these results, comprehensive monitoring with narrow intervals between sampling dates, more sample sites along all waterways, and proximate observation of multiple trace metal elements are highly recommended. Moreover, as the part of the water quality governance system, an immediate and sustainable collective action by all stakeholders to control the pollution level is highly recommended, as this issue is linked to the security of the national food system and poses a local public health risk. PMID:29597320

Mapping of available heavy metals in Catamarca (Argentina)

NASA Astrophysics Data System (ADS)

Roca, N.; Pazos, M. S.; Bech, J.

2009-04-01

Copper, iron, manganese and zinc are four essential elements for plant growth. Mapping heavy metal migration and distribution in soils is a preliminary step in assessing heavy metal availability in soils. However, data of qualitative and quantitative trace elements composition of soils of Argentina are scarce. Despite the small amounts required by plants, agricultural soils are usually deficient in one or more micronutrients, therefore, their concentration in plant tissues falls below the levels that allow optimal growth. Soil nature plays a fundamental role in the availability of micronutrients and their behaviour at a soil-plant level. The aim of this study is to determine the plant availability and areas of deficiency in agricultural soils with risk of salinization. The presented maps have been elaborated on the basis of the information provided by the monochromatic aerial photographs, scale 1:7000 and projected using the topographic information of the National Topographic Maps. Soils were sampled according to the spatial variation of soil types and land use. Sampling points were geo-referenced. Soil samples were analyzed at the laboratory for complete physicochemical and mineralogical characteristics. The percentage of organic matter is the determining factor in the presence and distribution of the available metals in the soils of the studied area, being the top horizon the one of greatest accumulation. CuDTPA, FeDPTA and MnDPTA are mobile within the profile, whereas ZnDPTA remains adsorbed without vertical displacement. ZnDTPA is the only available metal which also shows differences due to soil salinity and textural classes. However, soil geochemical conditions imply low extractability and a certain difficulty for micronutrient absorption by plants.

Water quality mapping of Laguna de Bay and its watershed, Philippines

NASA Astrophysics Data System (ADS)

Saito, S.; Nakano, T.; Shin, K.; Maruyama, S.; Miyakawa, C.; Yaota, K.; Kada, R.

2011-12-01

Laguna de Bay (or Laguna Lake) is the largest lake in the Philippines, with a surface area of 900 km2 and its watershed area of 2920 km2 (Santos-Borja, 2005). It is located on the southwest part of the Luzon Island and its watershed contains 5 provinces, 49 municipalities and 12 cities, including parts of Metropolitan Manila. The water quality in Laguna de Bay has significantly deteriorated due to pollution from soil erosion, effluents from chemical industries, and household discharges. In this study, we performed multiple element analysis of water samples in the lake and its watersheds for chemical mapping, which allows us to evaluate the regional distribution of elements including toxic heavy metals such as Cd, Pb and As. We collected water samples from 24 locations in Laguna de Bay and 160 locations from rivers in the watersheds. The sampling sites of river are mainly downstreams around the lake, which covers from urbanized areas to rural areas. We also collected well water samples from 17 locations, spring water samples from 10 locations, and tap water samples from 21 locations in order to compare their data with the river and lake samples and to assess the quality of household use waters. The samples were collected in dry season of the study area (March 13 - 17 and May 2 - 9, 2011). The analysis was performed at the Research Institute for Humanity and Nature (RIHN), Japan. The concentrations of the major components (Cl, NO3, SO4, Ca, Mg, Na, and K) dissolved in the samples were determined with ion chromatograph (Dionex Corporation ICS-3000). We also analyzed major and trace elements (Li, B, Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn Ga, Ge, As, Se, Rb, Sr, Y, Zr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Pb and U) with inductively coupled plasma-mass spectrometry (ICP-MS, Agilent Technologies 7500cx). The element concentrations of rivers are characterized by remarkable regional variations. For example, heavy metals such as Ni, Cd and Pb are markedly high in the western region as compared to the eastern region implying that the chemical variation reflects the urbanization in the western region. On the other hand, As contents is relatively high in the south of the lake and some inflowing rivers in the area. The higher concentration of As is also observed in the spring water samples in the area. Therefore, the source of As in the area is probably natural origin rather than anthropogenic. Although river water samples in western watersheds have high concentrations of heavy metals, the lake water samples in western area of the lake are not remarkably high in heavy metals. This inconsistency implies that the heavy metals flowed into the western lake from heavy metal-enriched rives have precipitated on the bottom of the lake. The polluted sediments may induce the pollution of benthos resulting in increase of the risks of food pollution through the bioaccumulation in the ecosystem.

Creation of half-metallic f -orbital Dirac fermion with superlight elements in orbital-designed molecular lattice

NASA Astrophysics Data System (ADS)

Cui, Bin; Huang, Bing; Li, Chong; Zhang, Xiaoming; Jin, Kyung-Hwan; Zhang, Lizhi; Jiang, Wei; Liu, Desheng; Liu, Feng

2017-08-01

Magnetism in solids generally originates from the localized d or f orbitals that are hosted by heavy transition-metal elements. Here, we demonstrate a mechanism for designing a half-metallic f -orbital Dirac fermion from superlight s p elements. Combining first-principles and model calculations, we show that bare and flat-band-sandwiched (FBS) Dirac bands can be created when C20 molecules are deposited into a two-dimensional hexagonal lattice, which are composed of f -molecular orbitals (MOs) derived from s p -atomic orbitals (AOs). Furthermore, charge doping of the FBS Dirac bands induces spontaneous spin polarization, converting the system into a half-metallic Dirac state. Based on this discovery, a model of a spin field effect transistor is proposed to generate and transport 100% spin-polarized carriers. Our finding illustrates a concept to realize exotic quantum states by manipulating MOs, instead of AOs, in orbital-designed molecular crystal lattices.

Metallothionein from Wild Populations of the African Catfish Clarias gariepinus: From Sequence, Protein Expression and Metal Binding Properties to Transcriptional Biomarker of Metal Pollution.

PubMed

M'kandawire, Ethel; Mierek-Adamska, Agnieszka; Stürzenbaum, Stephen R; Choongo, Kennedy; Yabe, John; Mwase, Maxwell; Saasa, Ngonda; Blindauer, Claudia A

2017-07-18

Anthropogenic pollution with heavy metals is an on-going concern throughout the world, and methods to monitor release and impact of heavy metals are of high importance. With a view to probe its suitability as molecular biomarker of metal pollution, this study has determined a coding sequence for metallothionein of the African sharptooth catfish Clarias gariepinus . The gene product was recombinantly expressed in Escherichia coli in presence of Zn(II), Cd(II), or Cu, and characterised by Electrospray Ionisation Mass Spectrometry and elemental analysis. C. gariepinus MT displays typical features of fish MTs, including 20 conserved cysteines, and seven bound divalent cations (Zn(II) or Cd(II)) when saturated. Livers from wild C. gariepinus fish collected in all three seasons from four different sites on the Kafue River of Zambia were analysed for their metal contents and for MT expression levels by quantitative PCR. Significant correlations were found between Zn and Cu levels and MT expression in livers, with MT expression clearly highest at the most polluted site, Chililabombwe, which is situated in the Copperbelt region. Based on our findings, hepatic expression of MT from C. gariepinus may be further developed as a major molecular biomarker of heavy metal pollution resulting from mining activities in this region.

Determination of Heavy Metals in Almonds and Mistletoe as a Parasite Growing on the Almond Tree Using ICP-OES or ICP-MS.

PubMed

Kamar, Veysi; Dağalp, Rukiye; Taştekin, Mustafa

2017-12-28

In this study, the elements of Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, Sr, Pb, Ti, and Zn were determined in the leaves, fruits, and branches of mistletoe, (Viscum albüm L.), used as a medicinal plant, and in the leaves, branches and barks of almond tree which mistletoe grows on. The aim of the study is to investigate whether the mistletoe are more absorbent than the almond tree in terms of the heavy metal contents and the determination of the amount of the elements penetrated into the mistletoe from the almond tree. ICP-MS (inductively coupled plasma-mass spectrometry) was used for the analysis of As, Cd, Mo, and Pb, whereas ICP-OES (inductively coupled plasma optical emission spectrometry) was used for the other elements. The results obtained were statistically evaluated at 95% confidence level. Within the results obtained in this study, it was determined whether there is a significant difference between metal elements in almond tree and mistletoe, or not. As a result, it was observed that there were higher contents of B, Ba, K, Mg, and Zn in the mistletoe than in the almond tree. K was found much higher than other elements in the mistletoe. On the other hand, Al, As, Ca, Cd, Cr, Cu, Fe, Mo, Ni, Sr, Pb, and Ti contents were determined to be more in almond tree than mistletoe.

Assessment of heavy metals in agricultural soils and their source apportionment: a Turkish district survey.

PubMed

Dartan, Güler; Taşpınar, Fatih; Toröz, İsmail

2015-03-01

This study aimed at investigating the impact of industrialization on the quality of agricultural soils in the district of Bandırma, Turkey, in terms of soil heavy metal contamination. Many soil and phosphogypsum samples were analyzed, and enrichment factors (EFs) were calculated. The average concentration gradient of metals in the soil (mg/kg) was As < Se < Sb < Pb < Co < Cd < V < Cu < Ni < Zn < Cr < P < Mn < Na < K < Mg < Fe < Ca < Al. According to the Pearson cross-correlation results for the element pairs of Fe-Mg (0.635), Fe-Cu (0.863), Fe-Cd (0.545), Cu-Cd (0.630), Mn-Cr (0.698), Mn-Al (0.523), Cr-Mg (0.543), Al-P (0.508), Na-K (0.616), and C-Zn (0.703), the metal enrichments in the soil were found to be moderately high and significant. In the majority of soil samples, Ni, Cu, Co, Zn, Se, Pb, and Cr were moderately enriched whereas Sb and Cd were extremely highly enriched. A factor analysis (FA) was applied to the cross-correlations of the elements to identify their sources. Six significant factors were extracted with the help of FA, explaining 77.22 % of the total variance, and the elements loaded on these factors were interpreted. The evaluations of the factors showed that the study area has been exposed to heavy metal pollution from anthropogenic sources considering the high levels of Cr, Cd, Cu, P, V, Zn, Ni, Sb, and Pb in the soil and the higher EFs falling in the range of 2.54-372.87. Moreover, the soil concentrations of Mn, Mg, Co, Al, K, and Ca were also high, but they were of lithogenic in origin according to the FA.

Models of H II regions - Heavy element opacity, variation of temperature

NASA Technical Reports Server (NTRS)

Rubin, R. H.

1985-01-01

A detailed set of H II region models that use the same physics and self-consistent input have been computed and are used to examine where in parameter space the effects of heavy element opacity is important. The models are briefly described, and tabular data for the input parameters and resulting properties of the models are presented. It is found that the opacities of C, Ne, O, and to a lesser extent N play a vital role over a large region of parameter space, while S and Ar opacities are negligible. The variation of the average electron temperature T(e) of the models with metal abundance, density, and T(eff) is investigated. It is concluded that by far the most important determinator of T(e) is metal abundance; an almost 7000 K difference is expected over the factor of 10 change from up to down abundances.

Honeybees and honey as monitors for heavy metal contamination near thermal power plants in Mugla, Turkey.

PubMed

Silici, Sibel; Uluozlu, Ozgur Dogan; Tuzen, Mustafa; Soylak, Mustafa

2016-03-01

In the present work, 6 honeydew samples of known geographical and botanical origins and 11 honeybee samples were analyzed to detect possible contamination by the thermoelectric power plants in Mugla, Turkey. The contents of trace elements were determined by atomic absorption spectrometry after application of microwave digestion. The samples from the thermal power plants, which were 10-22 km away from the hives, that did not cause pollution in honeydew honeys were also analyzed. The levels of copper, cadmium (Cd), lead (Pb), zinc, manganese, iron, chromium, nickel, and aluminum were similar to the values found in other recent studies in literature. However, it was found that the contamination levels of the toxic elements such as Pb and Cd in honeybee samples measured relatively higher than that of honey samples. The study concludes that honeybees may be better bioindicators of heavy metal pollution than honey. © The Author(s) 2013.

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

Role of extrinsic arbuscular mycorrhizal fungi in heavy metal-contaminated wetlands with various soil moisture levels.

PubMed

Zheng, S; Wang, C; Shen, Z; Quan, Y; Liu, X

2015-01-01

This study presents an efficient heavy metal (HM) control method in HM-contaminated wetlands with varied soil moisture levels through the introduction of extrinsic arbuscular mycorrhizal fungi (AMF) into natural wetland soil containing indigenous AMF species. A pot culture experiment was designed to determine the effect of two soil water contents (5-8% and 25-30%), five extrinsic AMF inoculants (Glomus mosseae, G. clarum, G. claroideum, G. etunicatum, and G. intraradices), and HM contamination on root colonization, plant growth, and element uptake of common reed (Phragmites australis (Cav.) Trin. ex Steudel) plantlets in wetland soils. This study showed the prevalence of mycorrhizae in the roots of all P. australis plantlets, regardless of extrinsic AMF inoculations, varied soil moisture or HM levels. It seems that different extrinsic AMF inoculations effectively lowered HM concentrations in the aboveground tissues of P. australis at two soil moisture levels. However, metal species, metal concentrations, and soil moisture should also be very important factors influencing the elemental uptake performance of plants in wetland ecosystems. Besides, the soil moisture level significantly influenced plant growth (including height, and shoot and root dry weight (DW)), and extrinsic AMF inoculations differently affected shoot DW.

Assessing pollution in a Mediterranean lagoon using acid volatile sulfides and estimations of simultaneously extracted metals.

PubMed

Zaaboub, Noureddine; Helali, Mohamed Amine; Martins, Maria Virgínia Alves; Ennouri, Rym; Béjaoui, Béchir; da Silva, Eduardo Ferreira; El Bour, Monia; Aleya, Lotfi

2016-11-01

Bizerte Lagoon is a southern Mediterranean semi-enclosed lagoon with a maximum depth of 12 m. After assessing sediment quality, the authors report on the physicochemical characteristics of the lagoon's surface sediment using SEM (simultaneously extracted metals) and AVS (acid volatile sulfides) as proxies. Biogeochemical tools are used to investigate the environmental disturbance at the water-sediment interface by means of SEM and AVS to seek conclusions concerning the study area's pollution status. Results confirm accumulation of trace elements in sediment. The use of the SEM-AVS model with organic matter in sediment (ƒOC) confirms possible bioavailability of accumulated trace elements, especially Zn, in the southern part of the lagoon, with organic matter playing an important role in SEM excess correction to affirm a nontoxic total metal sediment state. Individual trace element toxicity is dependent on the bioavailable fraction of SEM Metal on sediment, as is the influence of lagoon inflow from southern water sources on element bioavailability. Appropriate management strategies are highly recommended to mitigate any potential harmful effects on health from this heavy-metal-based pollution.

Heavy metals in atmospheric surrogate dry deposition

PubMed

Morselli; Cecchini; Grandi; Iannuccilli; Barilli; Olivieri

1999-02-01

This paper describes a methodological approach for the assessment of the amount of surrogate dry deposition of several toxic heavy metals (Cd, Cr, Cu, Ni, Pb, V, Zn) associated with atmospheric particulate matter at ground level. The objectives of the study were twofold: i) the evaluation of several techniques for the digestion of dry deposition samples for trace metal analysis; ii) the comparison of the results from two samplers with different collecting surfaces. A dry solid surface sampler (DRY sampler, Andersen--USA) and a water layer surface sampler (DAS sampler--MTX Italy) were employed. The samples were collected over a one-year period in an urban site of Bologna (northern Italy). A description is given of the complete procedure, from sampling to data elaboration, including sample storage, digestion and analytical methods. According to the results obtained with three different digestion techniques (Teflon bomb, microwave digester and Teflon flask with vapour cooling system), the highest recovery rate was achieved by the Teflon bomb procedure employing an NBS 1648 Standard Reference Material; 90-95% of the elements considered were recovered by dissolution in a pressurized Teflon bomb with an HNO3-HF mixture. Given these results, the technique was adopted for dry deposition sample digestion. On the basis of the amount of heavy metals measured as monthly deposition fluxes (microg/m2), the collecting efficiency of the DAS sampler for a number of elements was found to be as much as two to three times greater than that of the DRY sampler.

Sex, age, and tissue specific accumulation of eight metals, arsenic, and selenium in the European hedgehog (Erinaceus europaeus).

PubMed

Rautio, Anni; Kunnasranta, Mervi; Valtonen, Anu; Ikonen, Mirva; Hyvärinen, Heikki; Holopainen, Ismo J; Kukkonen, Jussi V K

2010-11-01

Many insectivores have been shown to be sensitive to heavy metals and therefore suitable for biomonitoring purposes. In Finland, the hibernation period of the European hedgehog (Erinaceus europaeus) is long, and during hibernation the stress caused by environmental toxins may be crucial. Concentrations of cadmium (Cd), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), arsenic (As), and selenium (Se) were measured in a population of hedgehogs in the town of Joensuu in eastern Finland during the summers of 2004 and 2005. The analyzed tissues were kidney, liver, hair, and spine. The sampled hedgehogs (n = 65) were mainly road-killed animals. As expected, the concentrations of heavy metals were low because the hedgehogs were living in a comparatively unpolluted area. Significant increases with age were found in Cd concentrations (kidney, liver, and spine) and some essential elements (Se in spine, kidney, and liver; Mo in kidney and liver; Cu in spine; Fe in liver; and Mn in spine). Age accumulation and correlations between Se and Cd and between Mo and Cd may indicate the protective roles of Se and Mo against Cd toxicity in hedgehogs, in which Cd is already at comparatively low concentrations. Sex had no significant effect on concentrations of the elements studied. In conclusion, age is an important parameter to be taken into account when studying heavy-metal concentrations in hedgehogs and other insectivores.

Heavy metals distribution in soils surrounding an abandoned mine in NW Madrid (Spain) and their transference to wild flora.

PubMed

Moreno-Jiménez, Eduardo; Peñalosa, Jesús M; Manzano, Rebeca; Carpena-Ruiz, Ramón O; Gamarra, Roberto; Esteban, Elvira

2009-03-15

The present work concerns the distribution and mobility of heavy metals (Fe, Mn, Cu, Zn and Cd) in the surrounding soils of a mine site and their transfer to wild flora. Thus, soils and plants were sampled from a mining valley in NW Madrid (Spain), and total and extractable heavy metals were analysed. Soils affected by mining activities presented total Cd, Cu and Zn concentrations above toxic thresholds. The percentage of extractable element was highest for Cd and lowest for Cu. A highly significant correlation was observed between the total and extractable concentrations of metals in soils, indicating that, among the factors studied, total metals concentration is the most relevant for heavy metals extractability in these soils. (NH(4))(2)SO(4)-extractable metal concentrations in soils are correlated better with metal concentrations in several plant species than total metals in soils, and thus can be used as a suitable and robust method for the estimation of the phytoavailable fraction present in soils. Twenty-five vascular plant species (3 ferns and 22 flowering plants) were analysed, in order to identify exceptional characteristics that would be interesting for soil phytoremediation and/or reclamation. High Cd and Zn concentrations have been found in the aerial parts of Hypericum perforatum (Cd), Salix atrocinerea (Cd, Zn) and Digitalis thapsi (Cd, Zn). The present paper is, to the best of our knowledge, the first report of the metal accumulation ability of the two latter plant species. The phytoremediation ability of S. atrocinerea for Cd and Zn was estimated, obtaining intervals of time that could be considered suitable for the phytoextraction of polluted soils.

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.

Sorption interactions of heavy metals with biochar in soil remediation studies

NASA Astrophysics Data System (ADS)

Fristak, Vladimir; Friesl-Hanl, Wolfgang; Wawra, Anna; Soja, Gerhard

2015-04-01

The search for new materials in soil remediation applications has led to new conversion technologies such as carbonization and pyrolysis. Biochar represents the pyrolytic product of different biomass input materials processed at 350-1000°C and anoxic conditions. The pyrolysis temperature and feedstock have a considerable influence on the quality of the charred product and also its main physico-chemical properties. Biochar as porous material with large specific surface and C-stability is utilized in various environmental and agricultural technologies. Carbon sequestration, increase of soil water-holding capacity and pH as well as sorption of different xenobiotics present only a fraction of the multitude of biochar application possibilities. Heavy metals as potential sources of ecotoxicological risks are characterized by their non-degradability and the potential transfer into the food chain. Carbonaceous materials have been used for a long time as sorbents for heavy metals and organic contaminants in soil and water technologies. The similarity of biochar with activated carbon predetermines this material as remediation tool which plays an important role in heavy metal immobilization and retention with a parallel reduction in the risk of ground water and food crop contamination. In all this processes the element-specific sorption behaviour of biochar creates new conditions for pollutant binding. Sorption interaction and separation of contaminants from soil solution or waste effluent can be affected by wide-ranging parameters. In detail, our study was based on batch-sorption comparisons of two biochars produced from wood chips and green waste residues. We observed that sorption efficiency of biochar for model bivalent heavy metals (Cd, Zn, Cu) can be influenced by equilibrium parameters such as pH, contact time, initial concentration of metal in reaction solutions, presence of surfactants and chemical modification by acid hydrolysis, esterification and methylation. The study of sorption mechanisms showed differences in the sorption of the targeted heavy metals in relation to the contribution of ion-exchange and precipitation processes. We confirmed the effectivity of physico-chemical artificial aging on sorption capacity of biochar in terms of changes in surface structure. Based on these results, the application potential of biochar as sorption material for stabilizing heavy metals in soils is discussed.

Elements including metals in the atomizer and aerosol of disposable electronic cigarettes and electronic hookahs.

PubMed

Williams, Monique; Bozhilov, Krassimir; Ghai, Sanjay; Talbot, Prue

2017-01-01

Our purpose was to quantify 36 inorganic chemical elements in aerosols from disposable electronic cigarettes (ECs) and electronic hookahs (EHs), examine the effect of puffing topography on elements in aerosols, and identify the source of the elements. Thirty-six inorganic chemical elements and their concentrations in EC/EH aerosols were determined using inductively coupled plasma optical emission spectroscopy, and their source was identified by analyzing disassembled atomizers using scanning electron microscopy and energy dispersive X-ray spectroscopy. Of 36 elements screened, 35 were detected in EC/EH aerosols, while only 15 were detected in conventional tobacco smoke. Some elements/metals were present in significantly higher concentrations in EC/EH aerosol than in cigarette smoke. Concentrations of particular elements/metals within EC/EH brands were sometimes variable. Aerosols generated at low and high air-flow rates produced the same pattern of elements, although the total element concentration decreased at the higher air flow rate. The relative amount of elements in the first and last 60 puffs was generally different. Silicon was the dominant element in aerosols from all EC/EH brands and in cigarette smoke. The elements appeared to come from the filament (nickel, chromium), thick wire (copper coated with silver), brass clamp (copper, zinc), solder joints (tin, lead), and wick and sheath (silicon, oxygen, calcium, magnesium, aluminum). Lead was identified in the solder and aerosol of two brands of EHs (up to 0.165 μg/10 puffs). These data show that EC/EH aerosols contain a mixture of elements, including heavy metals, with concentrations often significantly higher than in conventional cigarette smoke. While the health effects of inhaling mixtures of heated metals is currently not known, these data will be valuable in future risk assessments involving EC/EH elements/metals.

Elevated CO2 levels affects the concentrations of copper and cadmium in crops grown in soil contaminated with heavy metals under fully open-air field conditions.

PubMed

Guo, Hongyan; Zhu, Jianguo; Zhou, Hui; Sun, Yuanyuan; Yin, Ying; Pei, Daping; Ji, Rong; Wu, Jichun; Wang, Xiaorong

2011-08-15

Elevated CO(2) levels and the increase in heavy metals in soils through pollution are serious problems worldwide. Whether elevated CO(2) levels will affect plants grown in heavy-metal-polluted soil and thereby influence food quality and safety is not clear. Using a free-air CO(2) enrichment (FACE) system, we investigated the impacts of elevated atmospheric CO(2) on the concentrations of copper (Cu) or cadmium (Cd) in rice and wheat grown in soil with different concentrations of the metals in the soil. In the two-year study, elevated CO(2) levels led to lower Cu concentrations and higher Cd concentrations in shoots and grain of both rice and wheat grown in the respective contaminated soil. Elevated CO(2) levels slightly but significantly lowered the pH of the soil and led to changes in Cu and Cd fractionation in the soil. Our study indicates that elevated CO(2) alters the distribution of contaminant elements in soil and plants, thereby probably affecting food quality and safety.

HOW MANY NUCLEOSYNTHESIS PROCESSES EXIST AT LOW METALLICITY?

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

Hansen, C. J.; Montes, F.; Arcones, A., E-mail: cjhansen@lsw.uni-heidelberg.de, E-mail: cjhansen@dark-cosmology.dk, E-mail: montes@nscl.msu.edu, E-mail: almudena.arcones@physik.tu-darmstadt.de

Abundances of low-metallicity stars offer a unique opportunity to understand the contribution and conditions of the different processes that synthesize heavy elements. Many old, metal-poor stars show a robust abundance pattern for elements heavier than Ba, and a less robust pattern between Sr and Ag. Here we probe if two nucleosynthesis processes are sufficient to explain the stellar abundances at low metallicity, and we carry out a site independent approach to separate the contribution from these two processes or components to the total observationally derived abundances. Our approach provides a method to determine the contribution of each process to themore » production of elements such as Sr, Zr, Ba, and Eu. We explore the observed star-to-star abundance scatter as a function of metallicity that each process leads to. Moreover, we use the deduced abundance pattern of one of the nucleosynthesis components to constrain the astrophysical conditions of neutrino-driven winds from core-collapse supernovae.« less

The transcription factor MTF-1 is essential for basal and heavy metal-induced metallothionein gene expression.

PubMed

Heuchel, R; Radtke, F; Georgiev, O; Stark, G; Aguet, M; Schaffner, W

1994-06-15

We have described and cloned previously a factor (MTF-1) that binds specifically to heavy metal-responsive DNA sequence elements in the enhancer/promoter region of metallothionein genes. MTF-1 is a protein of 72.5 kDa that contains six zinc fingers and multiple domains for transcriptional activation. Here we report the disruption of both alleles of the MTF-1 gene in mouse embryonic stem cells by homologous recombination. The resulting null mutant cell line fails to produce detectable amounts of MTF-1. Moreover, due to the loss of MTF-1, the endogenous metallothionein I and II genes are silent, indicating that MTF-1 is required for both their basal and zinc-induced transcription. In addition to zinc, other heavy metals, including cadmium, copper, nickel and lead, also fail to activate metal-responsive promoters in null mutant cells. However, cotransfection of an MTF-1 expression vector and metal-responsive reporter genes yields strong basal transcription that can be further boosted by zinc treatment of cells. These results demonstrate that MTF-1 is essential for metallothionein gene regulation. Finally, we present evidence that MTF-1 itself is a zinc sensor, which exhibits increased DNA binding activity upon zinc treatment.

Modifications of chemical functional groups of Pandanus amaryllifolius Roxb and its effect towards biosorption of heavy metals

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

Abdullah, Mohd Zamri, E-mail: zamriab@petronas.com.my; Ismail, Siti Salwa

2015-07-22

The utilization of non-living biomass as an alternative biosorbent for heavy metal removal has gain a tremendous consideration through the years. Pandanus amaryllifolius Roxb or pandan leaves, which is widely used as food additives in the South East Asia region, has been selected for its viability in the said effort due to the presence of chemical functional groups on its cellular network that enables the sorption to occur. In order to elucidate the possible mechanisms participated during the heavy metal removal process, the biosorbent undergone a series of modification techniques to alter the chemical functional groups present on its constituent.more » From the outcome of the chemically-modified biosorbent being subjected to the contact with metal cations, nitrogen- and oxygen-containing groups present on the biosorbent are believed to be responsible for the metal uptake to occur through complexation mechanism. Modifying amine groups causes 14% reduction of Cu(II) uptake, whereas removing protein element increases the uptake to 26% as compared to the unmodified biosorbent. Also, scanning electron micrographs further suggested that the adsorption mechanism could perform in parallel, as attributed to the evidence of porous structure throughout the biosorbent fibrous nature.« less

Modifications of chemical functional groups of Pandanus amaryllifolius Roxb and its effect towards biosorption of heavy metals

NASA Astrophysics Data System (ADS)

Abdullah, Mohd. Zamri; Ismail, Siti Salwa

2015-07-01

The utilization of non-living biomass as an alternative biosorbent for heavy metal removal has gain a tremendous consideration through the years. Pandanus amaryllifolius Roxb or pandan leaves, which is widely used as food additives in the South East Asia region, has been selected for its viability in the said effort due to the presence of chemical functional groups on its cellular network that enables the sorption to occur. In order to elucidate the possible mechanisms participated during the heavy metal removal process, the biosorbent undergone a series of modification techniques to alter the chemical functional groups present on its constituent. From the outcome of the chemically-modified biosorbent being subjected to the contact with metal cations, nitrogen- and oxygen-containing groups present on the biosorbent are believed to be responsible for the metal uptake to occur through complexation mechanism. Modifying amine groups causes 14% reduction of Cu(II) uptake, whereas removing protein element increases the uptake to 26% as compared to the unmodified biosorbent. Also, scanning electron micrographs further suggested that the adsorption mechanism could perform in parallel, as attributed to the evidence of porous structure throughout the biosorbent fibrous nature.

Pop-rock music as precipitating cause in youth suicide.

PubMed

Litman, R E; Farberow, N L

1994-03-01

The plaintiffs in a law suit alleged that the heavy metal rock band Judas Priest, and its publisher CBS, were liable for damages to two youths who shot themselves after listening to the band's album. Crucial issues included "proximate cause" and "precipitating cause" in suicide, and the alleged role of subliminal messages. The judge ruled that although the "heavy metal" music might have had a toxic influence, the sounds and words are protected by the free speech first amendment. The influence of subliminal messages on behavior is unproven. There were many other elements in the personalities and situations of the victims to account for their self-destructive behavior.

Synthetic Developments of Nontoxic Quantum Dots.

PubMed

Das, Adita; Snee, Preston T

2016-03-03

Semiconductor nanocrystals, or quantum dots (QDs), are candidates for biological sensing, photovoltaics, and catalysis due to their unique photophysical properties. The most studied QDs are composed of heavy metals like cadmium and lead. However, this engenders concerns over heavy metal toxicity. To address this issue, numerous studies have explored the development of nontoxic (or more accurately less toxic) quantum dots. In this Review, we select three major classes of nontoxic quantum dots composed of carbon, silicon and Group I-III-VI elements and discuss the myriad of synthetic strategies and surface modification methods to synthesize quantum dots composed of these material systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ecological vulnerability: seasonal and spatial assessment of trace metals in soils and plants in the vicinity of a scrap metal recycling factory in Southwestern Nigeria.

PubMed

Owoade, O K; Awotoye, O O; Salami, O O

2014-10-01

The concentrations of selected heavy metals in the soil and vegetation in the immediate vicinity of a metal scrap recycling factory were determined in the dry and wet seasons using the Atomic Absorption Spectrophotometer. The results showed that the soil pH in all the sites indicated slight acidity (from 5.07 to 6.13), high soil organic matter content (from 2.08 to 5.60 %), and a well-drained soil of sandy loam textural composition. Soil heavy metal content in the dry season were 0.84-3.12 mg/kg for Pb, 0.26-0.46 mg/kg for Cd, 9.19-24.70 mg/kg for Zn, and 1.46-1.97 mg/kg for Cu. These values were higher than those in the wet season which ranged from 0.62-0.69 mg/kg for Pb, 0.67-0.78 mg/kg for Cd, 0.84-1.00 mg/kg for Zn, and 1.26-1.45 mg/kg for Cu. Except for cadmium in the dry season, the highest concentrations occurred in the northern side of the factory for all the elements in both seasons. An increase in the concentrations of the elements up to 350 m in most directions was also observed. There was no specific pattern in the level of the metals in the leaves of the plant used for the study. However, slightly elevated values were observed in the wet season (Pb 0.53 mg/kg, Cd 0.59 mg/kg, Cu 0.88 mg/kg) compared with the dry season values (Pb 0.50 mg/kg, Cd 0.57 mg/kg, Cu 0.83 mg/kg). This study showed that the elevated concentrations of these metals might be associated with the activities from the recycling plant, providing the basis for heavy metal pollution monitoring and control of this locality that is primarily used for agricultural purposes.

New developments in understanding the r-process from observations of metal-poor stars

NASA Astrophysics Data System (ADS)

Frebel, Anna

2015-04-01

In their atmospheres, old metal-poor Galactic stars retain detailed information about the chemical composition of the interstellar medium at the time of their birth. Extracting such stellar abundances enables us to reconstruct the beginning of the chemical evolution shortly after the Big Bang. About 5% of metal-poor stars with [Fe/H] < - 2 . 5 display in their spectrum a strong enhancement of neutron-capture elements associated with the rapid (r-) nucleosynthesis process that is responsible for the production of the heaviest elements in the Universe. This fortuity provides a unique opportunity of bringing together astrophysics and nuclear physics because these objects act as ``cosmic lab'' for both fields of study. The so-called r-process stars are thought to have formed from material enriched in heavy neutron-capture elements that were created during an r-process event in a previous generation supernova. It appears that the few stars known with this rare chemical signature all follow the scaled solar r-process pattern (for the heaviest elements with 56 <= Z <= 90 that is). This suggests that the r-process is universal - a surprising empirical finding and a solid result that can not be obtained from any laboratory on earth. While much research has been devoted to establishing this pattern, little attention has been given to the overall level of enhancement. New results will be presented on the full extent of r-process element enrichment as observed in metal-poor stars. The challenge lies in determining how the r-process material in the earliest gas clouds was mixed and diluted. Assuming individual r-process events to have contributed the observed r-process elements. We provide empirical estimates on the amount of r-process material produced. This should become a crucial constraint for theoretical nuclear physics models of heavy element nucleosynthesis.

Application of geoaccumulation index and enrichment factors on the assessment of heavy metal pollution in the sediments.

PubMed

Shafie, Nur Aliaa; Aris, Ahmad Zaharin; Zakaria, Mohamad Pauzi; Haris, Hazzeman; Lim, Wan Ying; Isa, Noorain Mohd

2013-01-01

An investigative study was carried out in Langat River to determine the heavy metal pollution in the sediment with 22 sampling stations selected for the collection of sediment samples. The sediment samples were digested and analyzed for extractable metal ((48)Cd, (29)Cu, (30)Zn, (33)As, (82)Pb) using the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Parameters, such as pH, Eh, electrical conductivity (EC), salinity, cation exchange capacity (CEC) and loss on ignition (LOI) were also determined. The assessment of heavy metal pollution was derived using the enrichment factors (EF) and geoaccumulation index (I(geo)). This study revealed that the sediment is predominantly by As > Cd > Pb > Zn > Cu. As recorded the highest EF value at 187.45 followed by Cd (100.59), Pb (20.32), Zn (12.42) and Cu (3.46). This is similar to the I(geo), which indicates that the highest level goes to As (2.2), exhibits moderately polluted. Meanwhile, Cd recorded 1.8 and Pb (0.23), which illustrates that both of these elements vary from unpolluted to moderately polluted. The Cu and Zn levels are below 0, which demonstrates background concentrations. The findings are expected to update the current status of the heavy metal pollution as well as creating awareness concerning the security of the river water as a drinking water source.

Bioaccumulation of metals and metalloids in medicinal plant Ipomoea pes-caprae from areas impacted by tsunami.

PubMed

Kozak, Lidia; Kokociński, Mikołaj; Niedzielski, Przemysław; Lorenc, Stanisław

2015-02-01

Tsunami events may have an enormous impact on the functioning of aquatic and terrestrial ecosystems by altering various relationships with biotic components. Concentrations of acid-leachable fractions of heavy metals and metalloids in soils and plant samples from areas affected by the December 2004 tsunami in Thailand were determined. Ipomoea pes-caprae, a common plant species growing along the seashore of this region, and frequently used in folk medicine, was selected to assess the presence of selected elements. Elevated amounts of Cd, Pb, Zn, and As in soil samples, and Pb, Zn, As, Se, Cr, and Ni in plant samples were determined from the tsunami-impacted regions for comparison with reference locations. The flowers of Ipomoea pes-caprae contained the highest amounts of these metals, followed by its leaves, and stems. In addition, its bioaccumulation factor (BAF) supports this capability of high metal uptake by Ipomoea pes-caprae from the areas affected by the tsunami in comparison with a reference site. This uptake was followed by the translocation of these elements to the various plant components. The presence of these toxic metals in Ipomoea pes-caprae growing in contaminated soils should be a concern of those who use this plant for medicinal purposes. Further studies on the content of heavy metals and metalloids in this plant in relation to human health concerns are recommended. © 2014 SETAC.

The determination of trace elements in crude oil and its heavy fractions by atomic spectrometry

NASA Astrophysics Data System (ADS)

Duyck, Christiane; Miekeley, Norbert; Porto da Silveira, Carmem L.; Aucélio, Ricardo Q.; Campos, Reinaldo C.; Grinberg, Patrícia; Brandão, Geisamanda P.

2007-09-01

A literature review on the determination of trace elements in crude oil and heavy molecular mass fractions (saturates, aromatics, resins and asphaltenes) by ICP-MS, ICP OES and AAS is presented. Metal occurrences, forms and distributions are examined as well as their implications in terms of reservoir geochemistry, oil refining and environment. The particular analytical challenges for the determination of metals in these complex matrices by spectrochemical techniques are discussed. Sample preparation based on ashing, microwave-assisted digestion and combustion decomposition procedures is noted as robust and long used. However, the introduction of non-aqueous solvents and micro-emulsions into inductively coupled plasmas is cited as a new trend for achieving rapid and accurate analysis. Separation procedures for operationally defined fractions in crude oil are more systematically applied for the observation of metal distributions and their implications. Chemical speciation is of growing interest, achieved by the coupling of high efficiency separation techniques (e.g., HPLC and GC) to ICP-MS instrumentation, which allows the simultaneous determination of multiple organometallic species of geochemical and environmental importance.

Variation in heavy metals and microelements in South African medicinal plants obtained from street markets.

PubMed

Street, R A; Kulkarni, M G; Stirk, W A; Southway, C; Van Staden, J

2008-08-01

South African medicinal plants are traditionally harvested from a wide range of undisclosed locations by plant gatherers. Thus, there is a risk that plant material may be exposed to a variety of pollutants. The variation in five heavy metals (arsenic, cadmium, cobalt, nickel, and lead) and six essential elements (boron, copper, iron, manganese, molybdenum, and zinc) was determined in commonly used South African medicinal plants obtained from street markets. Elemental content was determined using inductively coupled plasma optical emission spectrophotometry. The reliability of the procedure was ensured by analysing a certified reference material. Medicinal plant samples contained arsenic and cadmium at levels exceeding the World Health Organization limits of 1 and 0.3 mg kg(-1) respectively. Lead and nickel were detected in all samples. Elevated iron and manganese levels were recorded in certain plant species. Multiple metal contamination of parts of medicinal plants gives grounds for concern. This study emphasizes the unsafe consequences of the South African practice of collecting medicinal plants from undisclosed locations and making these readily available to the public.

Do heavy metals and metalloids influence the detoxification of organic xenobiotics in plants?

PubMed

Schröder, Peter; Lyubenova, Lyudmila; Huber, Christian

2009-11-01

Mixed pollution with trace elements and organic industrial compounds is characteristic for many spill areas and dumping sites. The danger for the environment and human health from such sites is large, and sustainable remediation strategies are urgently needed. Phytoremediation seems to be a cheap and environmentally sound option for the removal of unwanted compounds, and the hyperaccumulation of trace elements and toxic metals is seemingly independent from the metabolism of organic xenobiotics. However, stress reactions, ROS formation and depletion of antioxidants will also cause alterations in xenobiotic detoxification. Here, we investigate the capability of plants to detoxify chlorophenols via glutathione conjugation in a mixed pollution situation. Typha latifolia and Phragmites australis plants for the present study were grown under greenhouse conditions in experimental ponds. A Picea abies L. suspension culture was grown in a growth chamber. Cadmium sulphate, sodium arsenate and lead chloride in concentrations from 10 to 500 microM were administered to plants. Enzymes of interest for the present study were: glutathione transferase (GST), glutathione reductase, ascorbate peroxidase and peroxidase. Measurements were performed according to published methods. GST spectrophotometric assays included the model substrates CDNB, DCNB, NBC, NBoC and the herbicide Fluorodifen. Heavy metals lead to visible stress symptoms in higher plants. Besides one long-term experiment of 72 days duration, the present study shows time and concentration-dependent plant alterations already after 24 and 72 h Cd incubation. P. abies spruce cell cultures react to CdSO(4) and Na(2)HAsO(4) with an oxidative burst, similar to that observed after pathogen attack or elicitor treatment. Cd application resulted in a reduction in GSH and GSSG contents. When a heavy metal mixture containing Na(2)HAsO(4), CdSO(4) and PbCl(2) was applied to cultures, both GSH and GSSG levels declined. Incubation with 80 microM arsenic alone doubled GSSG values. Based on these results, further experiments were performed in whole plants of cattail and reed, using cadmium in Phragmites and cadmium and arsenic in Typha as inducers of stress. In Phragmites australis, GST activities for CDNB and DCNB were significantly reduced after short-term Cd exposure (24 h). In the same samples, all antioxidant enzymes increased with rising heavy metal concentrations. Typha latifolia rhizome incubation with Cd and As leads to an increase in glutathione reductase and total peroxidase activity and to a decrease in ascorbate peroxidase activity. Measurements of the same enzymes in leaves of the same plants show increased GR activities, but no change in peroxidases. GST conjugation for CDNB was depressed in both cattail rhizomes and leaves treated with Cd. After As application increased, DCNB enzyme activities were detected. T. latifolia and P. australis are powerful species for phytoremediation because they penetrate a large volume of soil with their extensive root and rhizome systems. However, an effective remediation process will depend on active detoxifying enzymes, and also on the availability of conjugation partners, e.g. glutathione and its analogues. Species-specific differences seem to exist between the regulations of primary defence enzymes like SOD, catalase, peroxidases, whereas others prefer to induce the glutathione-dependent enzymes. As long as the pollutant mix encountered is simple and dominated by heavy metals, plant defence might be sufficient. When pollution plumes contain heavy metals and organic xenobiotics at the same time, this means that part of the detoxification capacity, at least of glutathione-conjugating reactions, is withdrawn from the heavy metal front to serve other purposes. In fact, glutathione S-transferases show strong reactions in stressed plants or in the presence of heavy metals. The spruce cell culture was a perfect model system to study short-term responses on heavy metal impact. Overall, and on the canopy level, this inhibitory effect might result in a lower detoxification capacity for organic pollutants and thus interfere with phytoremediation. We present evidence that pollution with heavy metals will interfere with both the oxidative stress defence in plants, and with their ability to conjugate organic xenobiotics. Despite plant-species-dependent differences, the general reactions seem to include oxidative stress and an induction of antioxidative enzymes. Several processes seem to depend on direct binding of heavy metals to enzyme proteins, but effects on transcription are also observed. Induction of xenobiotic metabolism will be obtained at high heavy metal concentrations, when plant stress is elevated. Plants for phytoremediation of complex pollution mixtures have to be selected according to three major issues: uptake/accumulation capacity, antioxidative stress management, and detoxification/binding properties for both the trace elements and the organic xenobiotics. By way of this, it might be possible to speed up the desired remediation process and/or to obtain the desired end products. And, amongst the end products, emphasis should be laid on industrial building materials, biomass for insulation or biogas production, but not for feed and fodder. Each of these attempts would increase the chances for publicly accepted use of phytoremediation and help to cure the environment.

Heavy metal fluxes at the sediment-water interface of three coastal ecosystems from south-west of the Iberian Peninsula

PubMed

Blasco; Saenz; Gomez-Parra

2000-03-20

Concentrations of the heavy metals Cr, Cu, Fe and Mn were measured in sediments and porewater samples collected in three coastal ecosystems southwest of the Iberian Peninsula: the Odiel and Barbate River Salt Marshes and the Bay of Cadiz. Both the sediment and the porewater metal concentrations in the Odiel River Salt Marshes are higher than the values found in the Bay of Cadiz and Barbate River Salt Marsh, particularly for copper, a metal associated with mining activity. In porewater, the profiles were not the same as those in the solid phase and reflect the different behaviours of the elements in relation to the redox conditions. The heavy metals Cr and Cu show a typical enrichment in the porewater of the oxic zone. The heavy metals Mn and Fe show an increase in the porewater at the depths where the maximum nitrate and phosphate concentrations occur, respectively. Significant differences between background levels for each heavy metal in the various studied zones exist. Iron and Cu showed larger background levels in the Odiel River Salt Marshes than those in the Cadiz Bay and the Barbate River Salt Marshes. In the Bay of Cadiz the background levels are also high, particularly for Cr. At the Odiel River Salt Marshes the diffusive flux of Cu is high (1.3-230.1 microg cm(-2) year(-1)), which suggests that the Odiel River Salt Marshes are subject to strong contamination by Cu, which is presumably introduced to the sediment in particulate form. In the Bay of Cadiz, Cr is the only metal with positive diffusive flux (2.15 microg cm(-2) year(-1)). It is higher than those obtained in other coastal ecosystems including the Odiel River Salt Marshes. The positive diffusive flux of Cr has been associated with the input of this metal by the naval industry and the manufacturing of car and aircraft components.

Transversely Excited Atmospheric CO2 Laser-Induced Plasma Spectroscopy for the Detection of Heavy Metals in Soil

NASA Astrophysics Data System (ADS)

Khumaeni, A.; Sugito, H.; Setia Budi, W.; Yoyo Wardaya, A.

2018-01-01

A rapid detection of heavy metals in soil was presented by the metal-assisted gas plasma method using specific characteristics of a pulsed, transversely excited atmospheric (TEA) CO2 laser. The soil particles were placed in a hole made of acrylic plate. The sample was covered by a to prevent the soil particles from being blown off. The mesh also functioned to initiate a luminous plasma. When a TEA CO2 laser (1500 mJ, 200 ns) was focused on the soil sample, passing through the metal mesh, some of the laser energy was used to generate the gas plasma on the mesh surface, and the remaining laser energy was employed to ablate the soil particles. The fine, ablated soil particles moved into the gas plasma region to be dissociated and excited. Using this technique, analysis can be made with reduced sample pretreatment, and therefore a rapid analysis can be performed efficiently. The results proved that the signal to noise ratio (S/N) of the emission spectral lines is much better for the case of the present method (mesh method) compared to the case of standard laser-induced breakdown spectroscopy using the pellet method. Rapid detection of heavy metal elements in soil has been successfully carried out. The detection limits of Cu and Hg in soil were estimated to be 3 and 10 mg/kg, respectively. The present method has good potential for rapid and sensitive detection of heavy metals in soil samples.

Source origin and parameters influencing levels of heavy metals in TSP, in an industrial background area of Southern Italy

NASA Astrophysics Data System (ADS)

Ragosta, Maria; Caggiano, Rosa; D'Emilio, Mariagrazia; Macchiato, Maria

In this paper, we investigate the relationships among atmospheric concentration of trace elements and some meteorological parameters. In particular, the effects of different meteorological conditions on heavy metal levels are interpreted by means of a multivariate statistical approach. The analysed variables were measured during a monitoring survey that started in 1997, and this survey was carried out in order to evaluate the atmospheric concentrations of heavy metals in the industrial area of Tito Scalo (Basilicata Region, Southern Italy). Here we present and analyse the data set collected from 1997 to 1999. The data set includes daily concentrations of total suspended particulates (TSP), daily concentrations of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in TSP and daily meteoclimatic data (temperature, rainfall, speed and wind directions). Both the concentration level and the occurrence of peak concentration events are consistent with the characteristics of the study area: abundant small and medium industrial plants in a mountainous and unpolluted zone. Regarding the origin of sources of heavy metals in TSP, the statistical procedure allows us to identify three profiles: SP 1 and SP 2 related to industrial sources and SP 3 related to other sources (natural and/or anthropogenic). In particular, taking into account the effect of different meteorological conditions, we are able to distinguish the contribution of different fractions of the same metal in the detected source profiles.

Mobility and bio-availability of heavy metals in anthropogenically contaminated alluvial (deluvial) meadow soils (EUTRIC FLUVISOLS)

NASA Astrophysics Data System (ADS)

Dinev, Nikolai; Hristova, Mariana; Tzolova, Venera

2015-04-01

The total content of heavy metals is not sufficient to assess the pollution and the risk for environment as it does not provide information for the type and solubility of heavy metals' compounds in soils. The purpose was to study and determine the mobility of heavy metals in anthropogenically contaminated alluvial (delluvial) meadow soils spread around the non-ferrous plant near the town of Asenovgrad in view of risk assessment for environment pollution. Soil samples from monitoring network (1x1 km) was used. The sequential extraction procedure described by Zein and Brummer (1989) was applied. Results showed that the easily mobilizable cadmium compounds predominate in both contaminated and not contaminated soils. The stable form of copper (associated with silicate minerals, carbonates or amorphous and crystalline oxide compounds) predominates only in non polluted soils and reviles the risk of the environment contamination. Lead spreads and accumulates as highly soluble (mobile) compounds and between 72.3 and 99.6 percent of the total lead is bioavailable in soils. The procedure is very suitable for studying the mobility of technogenic lead and copper in alluvial soils with neutral medium reaction and in particular at the high levels of cadmium contamination. In soils with alkaline reaction - polluted and unpolluted the error of analysis increases for all studied elements.

Characterisation of mineralogical forms of barium and trace heavy metal impurities in commercial barytes by EPMA, XRD and ICP-MS.

PubMed

Ansari, T M; Marr, I L; Coats, A M

2001-02-01

This study was carried out to characterise the mineralogical forms of barium and the trace heavy metal impurities in commercial barytes of different origins using electron probe microanalysis (EPMA), X-ray diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS). Qualitative EPMA results show the presence of typically eight different minerals in commercial barytes including barite (BaSO4), barium feldspar, galena (PbS), pyrite (FeS2), sphalerite (ZnS), quartz (SiO2), and silicates, etc. Quantitative EPMA confirms that the barite crystals in the barytes contain some strontium and a little calcium, whereas trace heavy metals occur in the associated minerals. Analysis of aqua regia extracts of barytes samples by ICP-MS has shown the presence of a large number of elements in the associated minerals. Arsenic, copper and zinc concentrations correlate closely in all 10 samples. The findings suggest that barytes is not, as traditionally thought, an inert mineral, but is a potentially toxic substance due to its associated heavy metal impurities, which can be determined by an aqua regia digest without the need for complete dissolution of the barite itself. X-ray powder diffraction was not informative as the complex barite pattern masks the very weak lines from the small amounts of associated minerals.

TiO2/bone composite materials for the separation of heavy metal impurities from waste water solutions

NASA Astrophysics Data System (ADS)

Dakroury, G.; Labib, Sh.; Abou El-Nour, F. H.

2012-09-01

Pure bone material obtained from cow meat, as apatite-rich material, and TiO2-bone composite materials are prepared and studied to be used for heavy metal ions separation from waste water solutions. Meat wastes are chemically and thermally treated to control their microstructure in order to prepare the composite materials that fulfill all the requirements to be used as selective membranes with high performance, stability and mechanical strength. The prepared materials are analyzed using Hg-porosimetry for surface characterization, energy dispersive X-ray spectroscopy (EDAX) for elemental analysis and Fourier transform infrared spectroscopy (FTIR) for chemical composition investigation. Structural studies are performed using X-ray diffraction (XRD). Microstructural properties are studied using scanning electron microscopy (SEM) and specific surface area studies are performed using Brunauer-Emmet-Teller (BET) method. XRD studies show that multiphase structures are obtained as a result of 1h sintering at 700-1200 °C for both pure bone and TiO2-bone composite materials. The factors affecting the transport of different heavy metal ions through the selected membranes are determined from permeation flux measurements. It is found that membrane pore size, membrane surface roughness and membrane surface charge are the key parameters that control the transport or rejection of heavy metal ions through the selected membranes.

Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash.

PubMed

Kuboňová, L; Langová, Š; Nowak, B; Winter, F

2013-11-01

Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050°C and in a muffle oven at temperatures from 500 to 1200°C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simultaneous heavy metals removal and municipal sewage sludge dewaterability improvement in bioleaching processes by various inoculums.

PubMed

Shi, Chaohong; Zhu, Nengwu; Shang, Ru; Kang, Naixin; Wu, Pingxiao

2015-11-01

The heavy metals content and dewaterability of municipal sewage sludge (MSS) are important parameters affecting its subsequent disposal and land application. Six kinds of inoculums were prepared to examine the characteristics of heavy metals removal and MSS dewaterability improvement in bioleaching processes. The results showed that Cu, Zn and Cd bioleaching efficiencies (12 days) were 81-91, 87-93 and 81-89%, respectively, which were significantly higher than those of Fe-S control (P < 0.05) and blank control (P < 0.01). The bioleaching boosted by the prepared inoculums could also significantly enhance MSS dewaterability (P < 0.01). The centrifugal dehydration efficiency of MSS rose from 73.00 to 90.00% at day 12. Microscopic observations and energy dispersive spectrum analysis demonstrated that the dewaterability improvement might be attributed to the changes of sludge structure from flocculent to obvious granular and the formation of secondary minerals mainly consisting of iron, oxygen and sulfur elements. The results above demonstrated that bacterial consortium enriched from acid mine drainage (AMD) was suitable to boost sludge bioleaching for heavy metals removal and dewaterability improvement. It also suggested that the synergy of sulfur/ferrous-oxidizing bacteria (SFOB) enriched from AMD and the cooperation of exogenous and indigenous SFOB significantly promoted bioleaching efficiencies.

Combining multitracing and 2D-modelling to identify the dynamic of heavy metals during flooding.

NASA Astrophysics Data System (ADS)

Hissler, C.; Hostache, R.; Matgen, P.; Tosheva, Z.; David, E.; Bates, P.; Stille, P.

2012-04-01

Recent years have seen a growing awareness of the wider environmental significance of the sediment loads transported by rivers and streams. This includes the importance of suspended sediment in transporting heavy metals and the potential for these trace elements to be desorbed from the particles to the solution. That threaten the water quality and can cause severe impacts in downstream areas like wetlands and floodplains. Contemporary data on the sediment loads of rivers provide clear evidence of significant recent changes in the sediment fluxes and of several rivers in response to human activities. For instance, Trace elements (including heavy metals) that are currently considered to be undisturbed by human activities and used as tracers of continental crust derived material have become more and more involved in industrial processes. Mathematical models validated by in situ experimentations are the only available tool to predict the consequences of natural as well as man-induced environmental changes and impacts on sediment dynamics. They are approximate representations of complex natural systems and the evaluation of a model with respect to its ability to reproduce multiple criteria and behaviour of a real system is still problematic. Interactions between modellers and experimentalists improve significantly the interpretation of the modelling output and led to formulate more realistic assumptions on the behaviour of natural systems. The geochemical information, which appeared to be non-correlated with the hydrological standard parameters, provides new information and contributes to give an "orthogonal view" on the hydrologic system behaviour. Regarding the recent development in geochemical tracer applications in models, the multi-tracer approach (natural vs anthropogenic; elemental concentration-isotopic signature-radionuclide activity) may be a necessity to decrease significantly the uncertainties in sediment transport modelling. The objective of this study is to assess the risk of floodplain contamination in heavy metal due to river sediment deposition and to heavy metal partitioning between particulate and dissolved phases. We focus on a multidisciplinary approach combining environmental geochemistry (multitracing) and hydraulic modelling (using TELEMAC-2D). One important single flood event was selected to illustrate this innovative approach. During the entire flood, the river water was sampled every hour in order to collect the particulate and the dissolved fractions. All the tracers were analyzed in both fractions. An important set of hydrological and sedimentological data are used to reach a more efficient calibration of the TELEMAC modelling system. In addition to standard techniques of hydrochemistry, new approaches of in situ suspended sediment transport monitoring will help getting new insights on the hydraulic system behaviour.

[Study on microwave digestion of coal for the determination of multi-element by ICP-OES and ICP-MS].

PubMed

Wang, Hui; Song, Qiang; Yao, Qiang; Chen, Chang-He; Yu, Fei-Lu

2012-06-01

Effects of temperature and four acids (HNO3, HNO3/H2O2, HNO3/HF and HNO3/HF+H3BO3) on the coal decomposition by microwave digestion and the multi-element analysis were studied. SARM20 was used as a coal standard reference material. The contents of 10 mineral elements (Al, Ca, Fe, Mg, K, Na, S, Si, Sr and Ti) in the coal SARM20 were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). And the contents of 20 heavy metals (Li, Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Zr, Sn, Cs, Ba, Ce, Eu and Pb) were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the coal was completely decomposed by microwave digestion with HNO3/HF+ H3BO3 at 210 degrees C. Good recoveries for all elements in the coal SARM20 were obtained by this two-step microwave digestion method. The recoveries of the 10 mineral elements were from 87.5% to 98.8%, and the recoveries of the 20 heavy metals were from 85% to 112.5%. All RSDs of tests were below 3%.

Determination of the oxidation states of metals and metalloids: An analytical review

NASA Astrophysics Data System (ADS)

Vodyanitskii, Yu. N.

2013-12-01

The hazard of many heavy metals/metalloids in the soil depends on their oxidation state. The problem of determining the oxidation state has been solved due to the use of synchrotron radiation methods with the analysis of the X-ray absorption near-edge structure (XANES). The determination of the oxidation state is of special importance for some hazardous heavy elements (arsenic, antimony, selenium, chromium, uranium, and vanadium). The mobility and hazard of each of these elements depend on its oxidation state. The mobilities are higher at lower oxidation states of As, Cr, V, and Se and at higher oxidation states of Sb and U. The determination of the oxidation state of arsenic has allowed revealing its fixation features in the rhizosphere of hydrophytes. The known oxidation states of chromium and uranium are used for the retention of these elements on geochemical barriers. Different oxidation states have been established for vanadium displacing iron in goethite. The determination of the oxidation state of manganese in the rhizosphere and the photosynthetic apparatus of plants is of special importance for agricultural chemists.

Hubble Friday - Heavy Metal Stars

NASA Image and Video Library

2017-12-08

Hubble rocks out with heavy metal stars! This 10.5-billion-year-old globular cluster, NGC 6496, is home to heavy-metal stars of a celestial kind! The stars comprising this spectacular spherical cluster are enriched with much higher proportions of metals — elements heavier than hydrogen and helium are curiously known as metals in astronomy — than stars found in similar clusters. A handful of these high-metallicity stars are also variable stars, meaning that their brightness fluctuates over time. NGC 6496 hosts a selection of long-period variables — giant pulsating stars whose brightness can take up to, and even over, a thousand days to change — and short-period eclipsing binaries, which dim when eclipsed by a stellar companion. The nature of the variability of these stars can reveal important information about their mass, radius, luminosity, temperature, composition, and evolution, providing astronomers with measurements that would be difficult or even impossible to obtain through other methods. NGC 6496 was discovered in 1826 by Scottish astronomer James Dunlop. The cluster resides at about 35,000 light-years away in the southern constellation of Scorpius (The Scorpion). Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt Text credit: European Space Agency Read more: go.nasa.gov/1U2wqGW

Apis mellifera ligustica, Spinola 1806 as bioindicator for detecting environmental contamination: a preliminary study of heavy metal pollution in Trieste, Italy.

PubMed

Giglio, Anita; Ammendola, Anna; Battistella, Silvia; Naccarato, Attilio; Pallavicini, Alberto; Simeon, Enrico; Tagarelli, Antonio; Giulianini, Piero Giulio

2017-01-01

Honeybees have become important tools for the ecotoxicological assessment of soil, water and air metal contamination due to their extraordinary capacity to bioaccumulate toxic metals from the environment. The level of heavy metal pollution in the Trieste city was monitored using foraging bees of Apis mellifera ligustica from hives owned by beekeepers in two sites strategically located in the suburban industrial area and urban ones chosen as control. The metal concentration in foraging bees was determined by inductively coupled plasma-mass spectrometry. The chemical analysis has identified and quantified 11 trace elements accumulated in two different rank orders: Zn> Cu > Sr > Bi > Ni > Cr > Pb = Co > V > Cd > As in foraging bees from the suburban site and Zn > Cu > Sr > Cr > Ni > Bi > Co = V > Pb > As > Cd in bees from urban site. Data revealed concentrations of Cr and Cu significantly higher and concentration of Cd significantly lower in bees from urban sites. The spatial difference and magnitude order in heavy metal accumulation along the urban-suburban gradient are mainly related to the different anthropogenic activity within sampled sites and represent a risk for the human health of people living in the city. We discussed and compared results with the range of values reported in literature.

Elemental Concentrations in Roadside Dust Along Two National Highways in Northern Vietnam and the Health-Risk Implication.

PubMed

Phi, Thai Ha; Chinh, Pham Minh; Cuong, Doan Danh; Ly, Luong Thi Mai; Van Thinh, Nguyen; Thai, Phong K

2018-01-01

There is a need to assess the risk of exposure to metals via roadside dust in Vietnam where many people live along the road/highways and are constantly exposed to roadside dust. In this study, we collected dust samples at 55 locations along two major Highways in north-east Vietnam, which passed through different land use areas. Samples were sieved into three different particle sizes and analyzed for concentrations of eight metals using a X-ray fluorescence instrument. The concentrations and environmental indices (EF, I geo ) of metals were used to evaluate the degree of pollution in the samples. Among different land uses, industrial areas could be highly polluted with heavy metals in roadside dust, followed by commerce and power plants. Additionally, the traffic density probably played an important role; higher concentrations were observed in samples from Highway No. 5 where traffic is several times higher than Highway No. 18. According to the risk assessment, Cr poses the highest noncarcinogenic risk even though the health hazard index values of assessed heavy metals in this study were within the acceptable range. Our assessment also found that the risk of exposure to heavy metals through roadside dust is much higher for children than for adults.

THE PROPERTIES OF HEAVY ELEMENTS IN GIANT PLANET ENVELOPES

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

Soubiran, François; Militzer, Burkhard

The core-accretion model for giant planet formation suggests a two-layer picture for the initial structure of Jovian planets, with heavy elements in a dense core and a thick H–He envelope. Late planetesimal accretion and core erosion could potentially enrich the H–He envelope in heavy elements, which is supported by the threefold solar metallicity that was measured in Jupiter’s atmosphere by the Galileo entry probe. In order to reproduce the observed gravitational moments of Jupiter and Saturn, models for their interiors include heavy elements, Z , in various proportions. However, their effect on the equation of state of the hydrogen–helium mixturesmore » has not been investigated beyond the ideal mixing approximation. In this article, we report results from ab initio simulations of fully interacting H–He– Z mixtures in order to characterize their equation of state and to analyze possible consequences for the interior structure and evolution of giant planets. Considering C, N, O, Si, Fe, MgO, and SiO{sub 2}, we show that the behavior of heavy elements in H–He mixtures may still be represented by an ideal mixture if the effective volumes and internal energies are chosen appropriately. In the case of oxygen, we also compute the effect on the entropy. We find the resulting changes in the temperature–pressure profile to be small. A homogeneous distribution of 2% oxygen by mass changes the temperature in Jupiter’s interior by only 80 K.« less

VizieR Online Data Catalog: Behavior of heavy elements in H-He-Z mixtures (Soubiran+, 2016)

NASA Astrophysics Data System (ADS)

Soubiran, F.; Militzer, B.

2016-11-01

The core-accretion model for giant planet formation suggests a two-layer picture for the initial structure of Jovian planets, with heavy elements in a dense core and a thick H-He envelope. Late planetesimal accretion and core erosion could potentially enrich the H-He envelope in heavy elements, which is supported by the threefold solar metallicity that was measured in Jupiter's atmosphere by the Galileo entry probe. In order to reproduce the observed gravitational moments of Jupiter and Saturn, models for their interiors include heavy elements, Z, in various proportions. However, their effect on the equation of state of the hydrogen-helium mixtures has not been investigated beyond the ideal mixing approximation. In this article, we report results from ab initio simulations of fully interacting H-He-Z mixtures in order to characterize their equation of state and to analyze possible consequences for the interior structure and evolution of giant planets. Considering C, N, O, Si, Fe, MgO, and SiO2, we show that the behavior of heavy elements in H-He mixtures may still be represented by an ideal mixture if the effective volumes and internal energies are chosen appropriately. In the case of oxygen, we also compute the effect on the entropy. We find the resulting changes in the temperature-pressure profile to be small. A homogeneous distribution of 2% oxygen by mass changes the temperature in Jupiter's interior by only 80K. (3 data files).

Segregation of isotopes of heavy metals due to light-induced drift: results and problems

NASA Astrophysics Data System (ADS)

Sapar, A.; Aret, A.; Poolamäe, R.; Sapar, L.

2008-04-01

Atutov and Shalagin (1988) proposed light-induced drift (LID) as a physically well understandable mechanism to explain the formation of isotopic anomalies observed in CP stars. We have generalized the theory of LID and applied it to diffusion of heavy elements and their isotopes in quiescent atmospheres of CP stars. Diffusional segregation of isotopes of chemical elements is described by the equations of continuity and diffusion velocity. Computations of evolutionary sequences for the abundances of mercury isotopes in several model atmospheres have been made, using the Fortran 90 program SMART composed by the authors. Results confirm predominant role of LID in separation of isotopes.

Chemical characteristic of PM2.5 emission and inhalational carcinogenic risk of domestic Chinese cooking.

PubMed

Zhang, Nan; Han, Bin; He, Fei; Xu, Jia; Zhao, Ruojie; Zhang, Yujuan; Bai, Zhipeng

2017-08-01

To illustrate chemical characteristic of PM 2.5 emission and assess inhalational carcinogenic risk of domestic Chinese cooking, 5 sets of duplicate cooking samples were collected, using the most used 5 types of oil. The mass abundance of 14 elements, 5 water-soluble ions, organic carbon (OC), elemental carbon (EC) and 11 polycyclic aromatic hydrocarbons (PAHs) were calculated; the signature and diagnostic ratio of cooking in the domestic kitchen were analyzed; and carcinogenic risks of heavy metals and PAHs via inhalation were assessed in two scenarios. The analysis showed that OC was the primary composition in the chemical profile; Na was the most abundant element that might be due to the usage of salt; Cr and Pb, NO 3 - and SO 4 2- , Phe, FL and Pyr were the main heavy metals/water-soluble ions/PAHs, respectively. Phe and FL could be used to separate cooking and stationary sources, while diagnostic ratios of BaA/(BaA + CHR), BaA/CHR, BaP/BghiP and BaP/BeP should be applied with caution, as they were influenced by various cooking conditions. Carcinogenic risks of heavy metals and PAHs were evaluated in two scenarios, simulating the condition of cooking with no ventilation and with the range hood on, respectively. The integrated risk of heavy metals and PAHs was 2.7 × 10 -3 and 5.8 × 10 -6 , respectively, during cooking with no ventilation. While with the usage of range hood, only Cr(VI), As and Ni might induce potential carcinogenic risk. The difference in the chemical abundance in cooking sources found between this and other studies underlined the necessity of constructing locally representative source profiles under real conditions. The comparison of carcinogenic risk suggested that the potentially adverse health effects induced by inorganic compositions from cooking sources should not be ignored. Meanwhile, intervention methods, such as the operation of range hood, should be applied during cooking for health protection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentrations of lead, cadmium, mercury and other elements in seeds of Lupinus mutabilis and of other legumes.

PubMed

Gross, R; Auslitz, J; Schramel, P; Payer, H D

1987-01-01

Several species of legumes and varieties of lupins were examined for their heavy metal content in the seeds. Atomic absorption spectrometry was the main analytical tool. Validity and reproducibility of the results was checked by analyzing the same materials at two different laboratories performing the same technique. Additionally, inductively coupled plasma emission spectroscopy was applied. In grains of Lupinus mutabilis which constitute a traditional food in Andean populations, the following contents of heavy metals were determined: 0.10-0.25 microgram/g Cd; 0.5-1.6 microgram/g Pb; 0.10-0.15 microgram/g Hg. Seeds of other legumes contained 0.05-0.35 microgram/g Cd; 0.1-0.2 microgram/g Pb; 0.01-0.04 microgram/g Hg. The high lead content of lupins is easily reduced to one tenth by traditional extraction with boiling water. The mercury content, too, is decreased by this technique. The high manganese content of 1 300-1,400 micrograms/g of Lupinus albus compared to other legumes (25-37 micrograms/g) seems to be characteristic for this species and may be of nutritional significance. The comparison of the heavy metal contents of legume seeds of different origin and variety indicates a complex pattern of environmental and genetic factors that contribute to the specific metal contents of individual harvests. On the level of varieties the environmental factors (climate, soil, geology, agricultural techniques) seem to exhibit more important influences on the specific accumulation of heavy metals than genetic factors. In contrast, on the level of species or genera, the accumulation of heavy metals seems to be dominated by genetic factors rather than by environmental influences.

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.

Monitoring of heavy metal particle emission in the exhaust duct of a foundry using LIBS.

PubMed

Dutouquet, C; Gallou, G; Le Bihan, O; Sirven, J B; Dermigny, A; Torralba, B; Frejafon, E

2014-09-01

Heavy metals have long been known to be detrimental to human health and the environment. Their emission is mainly considered to occur via the atmospheric route. Most of airborne heavy metals are of anthropogenic origin and produced through combustion processes at industrial sites such as incinerators and foundries. Current regulations impose threshold limits on heavy metal emissions. The reference method currently implemented for quantitative measurements at exhaust stacks consists of on-site sampling of heavy metals on filters for the particulate phase (the most prominent and only fraction considered in this study) prior to subsequent laboratory analysis. Results are therefore known only a few days after sampling. Stiffer regulations require the development of adapted tools allowing automatic, on-site or even in-situ measurements with temporal resolutions. The Laser-Induced Breakdown Spectroscopy (LIBS) technique was deemed as a potential candidate to meet these requirements. On site experiments were run by melting copper bars and monitoring emission of this element in an exhaust duct at a pilot-scale furnace in a French research center dedicated to metal casting. Two approaches designated as indirect and direct analysis were broached in these experiments. The former corresponds to filter enrichment prior to subsequent LIBS interrogation whereas the latter entails laser focusing right through the aerosol for detection. On-site calibration curves were built and compared with those obtained at laboratory scale in order to investigate possible matrix and analyte effects. Eventually, the obtained results in terms of detection limits and quantitative temporal monitoring of copper emission clearly emphasize the potentialities of the direct LIBS measurements. Copyright © 2014 Elsevier B.V. All rights reserved.

Trace elements in blood of sea turtles Lepidochelys olivacea in the Gulf of California, Mexico.

PubMed

Zavala-Norzagaray, A A; Ley-Quiñónez, C P; Espinosa-Carreón, T L; Canizalez-Román, A; Hart, C E; Aguirre, A A

2014-11-01

This study determined the concentrations of heavy metals in blood collected from Pacific Ridley sea turtles (Lepidochelys olivacea) inhabiting the coast of Guasave, Mexico, in the Gulf of California. The highest reported metal concentration in blood was Zn, followed by Se. Of nonessential toxic metals, As was reported in higher percentage compared to Cd. The concentrations of metals detected were present as follows: Zn > Se > Mn > As > Ni > Cd > Cu. Cd concentration in blood is higher in our population in comparison with other populations of L. olivacea, and even higher in other species of sea turtles. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements, and is easily accessible and nonlethal for sea turtles.

Investigation of Media Effects on Removal of Heavy Metals in Bioretention Cells

NASA Astrophysics Data System (ADS)

Gülbaz, Sezar; Melek Kazezyilmaz-Alhan, Cevza; Copty, Nadim K.

2015-04-01

Heavy metals are the most toxic elements at high concentrations, although some of them such as Cu and Zn are essential to plants, humans, and animals within a limited value. However, some heavy metals, such as Pb, have adverse effects even at low concentrations. Therefore, it is known that the toxic metals such as Zn, Cu and Pb in storm water runoff are serious threat for aquatic organisms. It is very important to control and reduce heavy metal concentration in urban storm water runoff. There are several methods to remove the aforementioned toxic metals such as electrolyte extraction, chemical precipitation, ion-exchange, reverse osmosis, membrane filtration, adsorption, cementation, and electrochemical treatment technologies. However, these methods are highly expensive and hard to implement for treatment of big volumes of water such as storm water. For this purpose, Low Impact Development (LID) Best Management Practices (BMPs) have become popular to collect, infiltrate, and treat toxic metals in storm water runoff in recent years. LID-BMP is a land planning method which is used to manage storm water runoff and improve water quality by reducing contaminant in storm water runoff. Bioretention is an example of LID-BMP application of which usage has recently been started in storm water treatment. Researchers have been investigating the advantages of bioretention systems and this study contributes to these research efforts by seeking for the media effects of bioretention on heavy metal removal. For this purpose, batch sorption experiments were performed to determine the distribution coefficients and retardation factor of copper (Cu), lead (Pb), and zinc (Zn) for bioretention media such as mulch, turf, local or vegetative soil, sand and gravel. Furthermore, sorption reaction kinetics of Cu, Pb and Zn are tested in order to assess the sorption equilibrium time of these metals for 5 bioretention media. The results of sorption test show that turf has higher sorption capacity than mulch and local soil for heavy metals used in the experiment. On the other hand, sand and gravel have relatively lower sorption capacities. Linear equilibrium isotherm represents sorption of these metals for all bioretention media. The highest sorption is observed for Pb followed by Cu and Zn for all bioretention media. The time required for reaching equilibrium conditions for bioretention column media is ranged from 1 to 6 hours for each metal investigated.

Heavy Metal Pollution and Ecological Assessment around the Jinsha Coal-Fired Power Plant (China)

PubMed Central

Hu, Jiwei; Qin, Fanxin; Quan, Wenxuan; Cao, Rensheng; Wu, Xianliang

2017-01-01

Heavy metal pollution is a serious problem worldwide. In this study, 41 soil samples and 32 cabbage samples were collected from the area surrounding the Jinsha coal-fired power plant (JCFP Plant) in Guizhou Province, southwest China. Pb, Cd, Hg, As, Cu and Cr concentrations in soil samples and cabbage samples were analysed to study the pollution sources and risks of heavy metals around the power plant. The results indicate that the JCFP Plant contributes to the Pb, Cd, As, Hg, Cu, and Cr pollution in nearby soils, particularly Hg pollution. Cu and Cr in soils from both croplands and forestlands in the study area derive mainly from crustal materials or natural processes. Pb, Cd and As in soils from croplands arise partly through anthropogenic activities, but these elements in soils from forestlands originate mainly from crustal materials or natural processes. Hg pollution in soils from both croplands and forestlands is caused mainly by fly ash from the JCFP Plant. The cabbages grown in the study area were severely contaminated with heavy metals, and more than 90% of the cabbages had Pb concentrations exceeding the permissible level established by the Ministry of Health and the Standardization Administration of the People’s Republic of China. Additionally, 30% of the cabbages had As concentrations exceeding the permissible level. Because forests can protect soils from heavy metal pollution caused by atmospheric deposition, close attention should be given to the Hg pollution in soils and to the concentrations of Pb, As, Hg and Cr in vegetables from the study area. PMID:29258250

Heavy Metal Pollution and Ecological Assessment around the Jinsha Coal-Fired Power Plant (China).

PubMed

Huang, Xianfei; Hu, Jiwei; Qin, Fanxin; Quan, Wenxuan; Cao, Rensheng; Fan, Mingyi; Wu, Xianliang

2017-12-18

Heavy metal pollution is a serious problem worldwide. In this study, 41 soil samples and 32 cabbage samples were collected from the area surrounding the Jinsha coal-fired power plant (JCFP Plant) in Guizhou Province, southwest China. Pb, Cd, Hg, As, Cu and Cr concentrations in soil samples and cabbage samples were analysed to study the pollution sources and risks of heavy metals around the power plant. The results indicate that the JCFP Plant contributes to the Pb, Cd, As, Hg, Cu, and Cr pollution in nearby soils, particularly Hg pollution. Cu and Cr in soils from both croplands and forestlands in the study area derive mainly from crustal materials or natural processes. Pb, Cd and As in soils from croplands arise partly through anthropogenic activities, but these elements in soils from forestlands originate mainly from crustal materials or natural processes. Hg pollution in soils from both croplands and forestlands is caused mainly by fly ash from the JCFP Plant. The cabbages grown in the study area were severely contaminated with heavy metals, and more than 90% of the cabbages had Pb concentrations exceeding the permissible level established by the Ministry of Health and the Standardization Administration of the People's Republic of China. Additionally, 30% of the cabbages had As concentrations exceeding the permissible level. Because forests can protect soils from heavy metal pollution caused by atmospheric deposition, close attention should be given to the Hg pollution in soils and to the concentrations of Pb, As, Hg and Cr in vegetables from the study area.

Distribution and Multivariate Pollution Risks Assessment of Heavy Metals and Natural Radionuclides Around Abandoned Iron-Ore Mines in North Central Nigeria

NASA Astrophysics Data System (ADS)

Isinkaye, Omoniyi Matthew

2018-02-01

The Itakpe abandoned iron-ore mines constitute the largest iron-ore deposits in Nigeria with an estimated reserve of about three million metric tons of ore. The present effort is a part of a comprehensive study to estimate the environmental and radiological health hazards associated with previous mining operations in the study area. In this regard, heavy metals (Fe, Zn, Cu, Cd, Cr, Mn, Pb, Ni, Co and As) and natural radionuclides (U, Th and K) were measured in rock, soil and water samples collected at different locations within the mining sites. Atomic absorption and gamma-ray spectrometry were utilized for the measurements. Fe, Mn, Zn, Cu, Ni, Cd, Cr, Co Pb and As were detected at varying concentrations in rock and soil samples. Cd, Cr, Pb and As were not detected in water samples. The concentrations of heavy metals vary according to the following pattern; rock ˃ soil ˃ water. The mean elemental concentrations of K, U and Th are 2.9%, 0.8 and 1.2 ppm and 1.3%, 0.7 and 1.7 ppm, respectively, for rock and soil samples. Pearson correlation analyses of the results indicate that the heavy metals are mostly negatively correlated with natural radionuclides in the study area. Cancer and non-cancer risks due to heavy metals and radiological hazards due to natural radionuclides to the population living within the vicinity of the abandoned mines are lower than acceptable limits. It can, therefore, be concluded that no significant environmental or radiological health hazard is envisaged.

Synthesis and characterization of sulfur functionalized graphene oxide nanosheets as efficient sorbent for removal of Pb2+, Cd2+, Ni2+ and Zn2+ ions from aqueous solution: A combined thermodynamic and kinetic studies

NASA Astrophysics Data System (ADS)

Pirveysian, Mahtab; Ghiaci, Mehran

2018-01-01

A very simple, one pot method was used for preparation of sulfur functionalized graphene oxide (GO-SOxR) with sodium sulfide and water in reflux condition. The elemental analysis data showed high sulfur content up to 15%. EDS and XPS analysis also proved introduction of sulfur element. To make the sorbent more efficient operationally, the GO-SOxR was coated with a mesoporous shell of TiO2 or SiO2. The prepared sorbents were characterized by SEM, TEM, TGA, XPS, XRD, IR and EDS. GO-SOxR@TiO2 and GO-SOxR@SiO2 composites were tested for removal of Pb(II), Cd(II), Ni(II) and Zn(II) as heavy metal ions from aqueous solution in batch method. Adsorption of the heavy metal ions was studied kinetically, and the adsorption capacities of GO-SOxR, GO-SOxR@TiO2, and GO-SOxR@SiO2 were evaluated using equilibrium adsorption isotherms, and compared to other adsorbents used for removal of these heavy metals. Kinetic studies showed that the experimental data was fitted with pseudo second order model. The adsorption capacity of GO was significantly improved by sulfur functionalization and TiO2 coating.

Health risk assessment of urban population exposure to contaminants in the soils of the Southern Kuzbass

NASA Astrophysics Data System (ADS)

Osipova, N. A.; Tarasova, N. P.; Osipov, K. Yu.; Maximova, D. I.

2015-11-01

This study concerns the human health risk due to exposure of Co, Cu, As, Mn contained in soils of the Southern Kuzbass, where the coal industry is developed. Soil samples of 200 were taken in Mezhdurechensk - city with intensive coal mining and processing industries. The content of heavy metals in samples were determined using the electron spectroscopy. Several samples were also investigated by methods of the instrumental neutron activation analysis (INAA) and the inductively coupled plasma mass spectrometry (ICP-MS). With regard to the effects of heavy metals on the adult population health the total Hazard Index (HI) for ingestion and inhalation routes was 0.87×10-1 and 7.8×10-1 respectively. According to the contribution of Co, Cu, As, Mn to the total HI the elements form the decreasing series Mn (0,42-0,50)> Co (0.18-0.20)> Cu (0,13-0,19 )> As (0,05-0,09). These chemical elements are present in the organic and inorganic forms in coals and coal wastes. Ranking the city territory has shown that administrative districts have different HI values (8.4 10-1 - 8.8 10-1). When analyzing the human health risks of coal mining and coal-processing enterprises the impact of heavy metals as components of coals and combustion products should be taken into account.

Heavy metal accumulation in Pseudevernia furfuracea (L.) Zopf from the Karabük iron-steel factory in Karabük, Turkey.

PubMed

Cansaran-Duman, Demet; Atakol, Orhan; Atasoy, Ilknur; Kahya, Didem; Aras, Sümer; Beyaztaş, Taylan

2009-01-01

Pseudevernia furfuracea (L.) Zopf lichen specimens were collected every 5 km starting from around an iron-steel factory located in the central area of Karabük province, up to Yenice Forest. Zn, Cu, Mn, Fe, Pb, Ni, Cd, Cr contents were analyzed in the samples collected from polluted and unpolluted areas. A Pseudevernia furfuracea (L.) Zopf sample from Yenice Forest was used as a control. The reason for this choise was the abundance of species diversity, and therefore sample collection might cause a very low impact on natural population density. The forest is among the 100 forested areas that must be urgently taken under protection according to WWF (World Wildlife Fund) researches. Results of the current study manifested significant variations among the contents of these elements between stations. As expected, the pollution sources, such as iron-steel factory, roads and railroads, industry, heavy traffic, and waste treatment plants, have major impact on the heavy metal accumulation in P. furfuracea (L.) Zopf, and, in accordance to their location, samples 8 and 10 displayed high element accumulation. Surprisingly, although Yenice Forest is under protection, results of our study showed that the region is becoming polluted by the influence of many pollution sources in the area. The present study also confirms the efficient metal accumulation capacity of lichens.

Levels of rare earth elements, heavy metals and uranium in a population living in Baiyun Obo, Inner Mongolia, China: a pilot study.

PubMed

Hao, Zhe; Li, Yonghua; Li, Hairong; Wei, Binggan; Liao, Xiaoyong; Liang, Tao; Yu, Jiangping

2015-06-01

The Baiyun Obo deposit is the world's largest rare earth elements (REE) deposit. We aimed to investigate levels of REE, heavy metals (HMs) and uranium (U) based on morning urine samples in a population in Baiyun Obo and to assess the possible influence of rare earth mining processes on human exposure. In the mining area, elevated levels were found for the sum of the concentrations of light REE (LREE) and heavy REE (HREE) with mean values at 3.453 and 1.151 μg g(-1) creatinine, which were significantly higher than those in the control area. Concentrations of HMs and U in the population increased concomitantly with increasing REE levels. The results revealed that besides REE, HMs and U were produced with REE exploitation. Gender, age, educational level, alcohol and smoking habit were major factors contributing to inter-individual variation. Males were more exposed to these metals than females. Concentrations in people in the senior age group and those with only primary education were low. Drinking and smoking were associated with the levels of LREE, Cr, Cu, Cd and Pb in morning urine. Hence this study provides basic and useful information when addressing public and environmental health challenges in the areas where REE are mined and processed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mussel Shell Evaluation as Bioindicator For Heavy Metals

NASA Astrophysics Data System (ADS)

Andrello, Avacir Casanova; Lopes, Fábio; Galvão, Tiago Dutra

2010-05-01

Recently, in Brazil, it has appeared a new and unusual "plague" in lazer and commercial fishing. It is caused by the parasitic larval phase of certain native bivalve mollusks of fresh water known as "Naiades" and its involves the presence of big bivalve of fresh water, mainly Anodontites trapesialis, in the tanks and dams of the fish creation. These bivalve mollusks belong to the Unionoida Order, Mycetopodidae Family. The objective of the present work was to analyze the shells of these mollusks to verify the possibility of use as bioindicators for heavy metals in freshwater. The mollusks shells were collected in a commercial fishing at Londrina-PR. A qualitative analysis was made to determine the chemical composition of the shells and verify a possible correlation with existent heavy metals in the aquatic environment. In the inner part of the shells were identified the elements Ca, P, Fe, Mn and Sr and in the outer part were identified Ca, P, Fe, Mn, Sr and Cu. The Ca ratio of the outer part by inner part of the analyzed shells is around of 1, as expected, because Ca is the main compound of mollusks shells. The ratio of P, Fe, Mn, and Sr to the Ca were constant in all analyzed shells, being close to 0.015. The ratio Cu/Ca varied among the shells, showing that this mollusk is sensitive to concentration of this element in the aquatic environment.

Prediction of size-fractionated airborne particle-bound metals using MLR, BP-ANN and SVM analyses.

PubMed

Leng, Xiang'zi; Wang, Jinhua; Ji, Haibo; Wang, Qin'geng; Li, Huiming; Qian, Xin; Li, Fengying; Yang, Meng

2017-08-01

Size-fractionated heavy metal concentrations were observed in airborne particulate matter (PM) samples collected from 2014 to 2015 (spanning all four seasons) from suburban (Xianlin) and industrial (Pukou) areas in Nanjing, a megacity of southeast China. Rapid prediction models of size-fractionated metals were established based on multiple linear regression (MLR), back propagation artificial neural network (BP-ANN) and support vector machine (SVM) by using meteorological factors and PM concentrations as input parameters. About 38% and 77% of PM 2.5 concentrations in Xianlin and Pukou, respectively, were beyond the Chinese National Ambient Air Quality Standard limit of 75 μg/m 3 . Nearly all elements had higher concentrations in industrial areas, and in winter among the four seasons. Anthropogenic elements such as Pb, Zn, Cd and Cu showed larger percentages in the fine fraction (ø≤2.5 μm), whereas the crustal elements including Al, Ba, Fe, Ni, Sr and Ti showed larger percentages in the coarse fraction (ø > 2.5 μm). SVM showed a higher training correlation coefficient (R), and lower mean absolute error (MAE) as well as lower root mean square error (RMSE), than MLR and BP-ANN for most metals. All the three methods showed better prediction results for Ni, Al, V, Cd and As, whereas relatively poor for Cr and Fe. The daily airborne metal concentrations in 2015 were then predicted by the fully trained SVM models and the results showed the heaviest pollution of airborne heavy metals occurred in December and January, whereas the lightest pollution occurred in June and July. Copyright © 2017 Elsevier Ltd. All rights reserved.

Alaska's rare earth deposits and resource potential

USGS Publications Warehouse

Barker, James C.; Van Gosen, Bradley S.

2012-01-01

Alaska’s known mineral endowment includes some of the largest and highest grade deposits of various metals, including gold, copper and zinc. Recently, Alaska has also been active in the worldwide search for sources of rare earth elements (REE) to replace exports now being limitedby China. Driven by limited supply of the rare earths, combined with their increasing use in new ‘green’ energy, lighting, transportation, and many other technological applications, the rare earth metals neodymium, europium and, in particular, the heavy rare earth elements terbium, dysprosium and yttrium are forecast to soon be in critical short supply (U.S. Department of Energy, 2010).

Monitoring of Soil Contamination by Heavy Metals in the Impact Zone of Copper-Nickel Smelter on the Kola Peninsula

NASA Astrophysics Data System (ADS)

Kashulina, G. M.

2018-04-01

The results of landscape monitoring of the concentrations of acid-extractable Ni, Cu, Co, Mn, and Zn in soils of the local impact zone of the Severonikel industrial complex on the Kola Peninsula are discussed. The aim of monitoring studies was to reveal the spatial and temporal regularities of variation in the degree of soil contamination by heavy metals. In 2001-2011, the concentrations of acid-extractable compounds of the elements in the upper part of organic soil horizons around this plant exceeded their background concentrations by two orders of magnitude for Cu and Co and by three orders of magnitude for Ni. The degree of topsoil contamination with Ni, Cu, and Co generally corresponded to the distance of the plots from the contamination source and to the modern technogenic load. However, because of the long period of the emissions, their extreme amounts, and complex composition, indirect factors—the degree of technogenic soil degradation, the loss of soil organic matter, saturation of the surface soil layers by the contaminating metals, and competitive relationships between the elements—also affect soil contamination level. The concentrations of all the studied metals in the topsoil are characterized by considerable (1.5 to 7 times) variability in their long-term dynamics. The most important factors of this variability for Ni, Cu, and Co are the organic matter content of the samples and the amount of atmospheric precipitation in the year preceding the sampling. An inverse relationship between element concentrations in the soils and the amount of atmospheric precipitation attests to the dynamic nature and reversible character of the accumulation of heavy metals in the soils.

Pal 12 - A metal-rich globular cluster in the outer halo

NASA Technical Reports Server (NTRS)

Cohen, J. G.; Frogel, J. A.; Persson, S. E.; Zinn, R.

1980-01-01

New optical and infrared observations of several stars in the distant globular cluster Pal 12 show that they have CO strengths and heavy element abundances only slightly less than in M 71, one of the more metal-rich globular clusters. Pal 12 thus has a metal abundance near the high end of the range over which globular clusters exist and lies in the outer galactic halo. Its red horizontal branch is not anomalous in view of the abundance that has been found.

ICP-MS: Analytical Method for Identification and Detection of Elemental Impurities.

PubMed

Mittal, Mohini; Kumar, Kapil; Anghore, Durgadas; Rawal, Ravindra K

2017-01-01

Aim of this article is to review and discuss the currently used quantitative analytical method ICP-MS, which is used for quality control of pharmaceutical products. ICP-MS technique has several applications such as determination of single elements, multi element analysis in synthetic drugs, heavy metals in environmental water, trace element content of selected fertilizers and dairy manures. ICP-MS is also used for determination of toxic and essential elements in different varieties of food samples and metal pollutant present in the environment. The pharmaceuticals may generate impurities at various stages of development, transportation and storage which make them risky to be administered. Thus, it is essential that these impurities must be detected and quantified. ICP-MS plays an important function in the recognition and revealing of elemental impurities. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Selective determination of heavy metals (Cd, Pb, Cr) speciation forms from hortic anthrosols

NASA Astrophysics Data System (ADS)

Bulgariu, Dumitru; Bulgariu, Laura; Filipov, Feodor; Astefanei, Dan; Stoleru, Vasile

2010-05-01

In soils from glass houses, the speciation and inter-phases distribution processes of heavy metals have a particular dynamic, different in comparison with those from non-protected soils. The predominant distribution forms of heavy metals in such soils types are: complexes with low mass organic molecules, organic-mineral complexes, complexes with inorganic ligands (hydroxide-complexes, carbonate-complexes, sulphate-complexes, etc.) and basic salts. All of these have high stabilities in conditions of soils from glass houses, and in consequence, the separation and determination of speciation forms (which is directly connected with biodisponibility of heavy metals) by usual methods id very difficult and has a high uncertain degree. In this study is presented an original method for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils, which is based by the combination of solid-liquid sequential extraction (SPE) with the extraction in aqueous polymer-inorganic salt two-phase systems (ABS). The soil samples used for this study have been sampled from three different locations (glass houses from Iasi, Barlad and Bacau - Romania) where the vegetables cultivation have been performed by three different technologies. In this way was estimated the applicability and the analytical limits of method proposed by as, in function of the chemical-mineralogical and physical-chemical characteristics of soils. As heavy metals have been studied cadmium, lead and chromium, all being known for their high toxicity. The procedure used for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils has two main steps: (i) non-destructive separation of chemical-mineralogical associations and aggregates from soils samples - for this the separation method with heavy liquids (bromophorme) and isodynamic magnetic method have been used; (ii) sequential extraction of heavy metals from soil fractions separated in the first step, by using combined SPE-ABS procedure. For the preparation of combined extraction systems was used polyethylene glycol (with different molecular mass: 2000, 4000 and 8000). As phase-forming inorganic salts and as selective extracting agents we have used different usual inorganic reagents. The type and concentration of phase-forming salts have been selected in function of, both nature of extracted heavy metals and chemical-mineralogical characteristics of soil samples. The experimental parameters investigated in this study are: molecular mass of polyethylene glycol and the concentration of polymeric solutions, nature and concentration of phase-forming salts, nature and concentration of extracting agents, pH in extraction system phase, type of extracted heavy metals, type of speciation forms of heavy metals and their concentrations. All these factors can influence significantly the efficiency and the selectivity of separation process. The experimental results have indicate that the combined SPE-ABS extraction systems have better separation efficiency, in comparison with traditional SPE systems and ca realized a accurate discrimination between speciation forms of heavy metals from soils. Under these conditions, the estimation of inter-phases distribution and biodisponibility of heavy metals has a high precision. On the other hand, when the combined SPE-ABS systems are used, the concomitant extraction of the elements from the same geochemical association with studied heavy metals (inevitable phenomena in case of separation by SPE procedures) is significant diminished. This increases the separation selectivity and facilitated the more accurate determination of speciation forms concentration. By adequate selection of extraction conditions can be realized the selective separation of organic-mineral complexes, which will permit to perform detailed studies about the structure and chemical composition of these. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07 and project PNCDI 2 - D5 no. 52-141 / 2008).

Analysis of heavy metal accumulation in fish from the coastal waters of Terengganu, Malaysia

NASA Astrophysics Data System (ADS)

Rosli, M. N. R.; Samat, S. B.; Yasir, M. S.

2018-04-01

Bioaccumulation of toxic metals in fish causes serious threats to the human when they are consumed. Thus, the detection of toxic element concentration levels in fish is important. The accumulation of four heavy metal concentration of Cd, Cu, Mn and Zn in fish was determined. Five fish species namely Epinephelus lanceolatus, Rastrelliger, Megalaspis cordyla, Bramidae and Siganus canaliculatus were collected from the coastal waters of Terengganu, Malaysia. The analysis was done using inductive coupled plasma-mass spectrometer (ICP-MS) technique. The accumulation of the four heavy metals in muscle tissues of the fish are lower compared to liver and gill tissues. Cd concentration was higher in liver tissues except in Megalaspis cordyla. Meanwhile Cu concentration was higher in liver for all selected fishes. Mn concentration was higher in gill tissues of all fish studied while Zn concentration was higher in gill tissues except in Epinephelus lanceolatus and Rastrelliger. The highest average level of heavy metal recorded in fish is Zn (11.05 × 10-2 ± 1.44 × 10-2 mg kg-1) followed by Mn (1.81 × 10-2 ± 0.58 × 10-2 mg kg-1), Cu (0.70 × 10-2 ± 0.10 × 10-2 mg kg-1) and Cd (0.52×10-2 ± 0.27 × 10-2 mg kg-1). The metal concentration found in this study was lower than the national and international Recommended Dietary Allowance (RDA) for human consumption. Long term monitoring system of metal bioaccumulation in fishes need to be done to provide useful information for the assessment of the potential health risks of metals in Malaysia.

Size distribution and concentrations of heavy metals in atmospheric aerosols originating from industrial emissions as predicted by the HYSPLIT model

NASA Astrophysics Data System (ADS)

Chen, Bing; Stein, Ariel F.; Maldonado, Pabla Guerrero; Sanchez de la Campa, Ana M.; Gonzalez-Castanedo, Yolanda; Castell, Nuria; de la Rosa, Jesus D.

2013-06-01

This study presents a description of the emission, transport, dispersion, and deposition of heavy metals contained in atmospheric aerosols emitted from a large industrial complex in southern Spain using the HYSPLIT model coupled with high- (MM5) and low-resolution (GDAS) meteorological simulations. The dispersion model was configured to simulate eight size fractions (<0.33, 0.66, 1.3, 2.5, 5, 14, 17, and >17 μm) of metals based on direct measurements taken at the industrial emission stacks. Twelve stacks in four plants were studied and the stacks showed considerable differences for both emission fluxes and size ranges of metals. We model the dispersion of six major metals; Cr, Co, Ni, La, Zn, and Mo, which represent 77% of the total mass of the 43 measured elements. The prediction shows that the modeled industrial emissions produce an enrichment of heavy metals by a factor of 2-5 for local receptor sites when compared to urban and rural background areas in Spain. The HYSPLIT predictions based on the meteorological fields from MM5 show reasonable consistence with the temporal evolution of concentrations of Cr, Co, and Ni observed at three sites downwind of the industrial area. The magnitude of concentrations of metals at two receptors was underestimated for both MM5 (by a factor of 2-3) and GDAS (by a factor of 4-5) meteorological runs. The model prediction shows that heavy metal pollution from industrial emissions in this area is dominated by the ultra-fine (<0.66 μm) and fine (<2.5 μm) size fractions.

Identification of source locations for atmospheric dry deposition of heavy metals during yellow-sand events in Seoul, Korea in 1998 using hybrid receptor models

NASA Astrophysics Data System (ADS)

Han, Young-Ji; Holsen, Thomas M.; Hopke, Philip K.; Cheong, Jang-Pyo; Kim, Ho; Yi, Seung-Muk

2004-10-01

Elemental dry deposition fluxes were measured using dry deposition plates from March to June 1998 in Seoul, Korea. During this spring sampling period several yellow-sand events characterized by long-range transport from China and Mongolia impacted the area. Understanding the impact of yellow-sand events on atmospheric dry deposition is critical to managing the heavy metal levels in the environment in Korea. In this study, the measured flux of a primarily crustal metal, Al and an anthropogenic metal, Pb was used with two hybrid receptor models, potential source contribution function (PSCF) and residence time weighted concentration (RTWC) for locating sources of heavy metals associated with atmospheric dry deposition fluxes during the yellow-sand events in Seoul, Korea. The PSCF using a criterion value of the 75th percentile of the measured dry deposition fluxes and RTWC results using the measured elemental dry deposition fluxes agreed well and consistently showed that there were large potential source areas in the Gobi Desert in China and Mongolia and industrial areas near Tianjin, Tangshan, and Shenyang in China. Major industrial areas of Shenyang, Fushun, and Anshan, the Central China loess plateau, the Gobi Desert, and the Alashan semi-desert in China were identified to be major source areas for the measured Pb flux in Seoul, Korea. For Al, the main industrial areas of Tangshan, Tianjin and Beijing, the Gobi Desert, the Alashan semi-desert, and the Central China loess plateau were found to be the major source areas. These results indicate that both anthropogenic sources such as industrial areas and natural sources such as deserts contribute to the high dry deposition fluxes of both Pb and Al in Seoul, Korea during yellow-sand events. RTWC resolved several high potential source areas. Modeling results indicated that the long-range transport of Al and Pb from China during yellow-sand events as well as non-yellow-sand spring daytimes increased atmospheric dry deposition of heavy metals in Korea.

Metallothionein from Wild Populations of the African Catfish Clarias gariepinus: From Sequence, Protein Expression and Metal Binding Properties to Transcriptional Biomarker of Metal Pollution

PubMed Central

M’kandawire, Ethel; Mierek-Adamska, Agnieszka; Stürzenbaum, Stephen R.; Choongo, Kennedy; Yabe, John; Mwase, Maxwell; Saasa, Ngonda; Blindauer, Claudia A.

2017-01-01

Anthropogenic pollution with heavy metals is an on-going concern throughout the world, and methods to monitor release and impact of heavy metals are of high importance. With a view to probe its suitability as molecular biomarker of metal pollution, this study has determined a coding sequence for metallothionein of the African sharptooth catfish Clarias gariepinus. The gene product was recombinantly expressed in Escherichia coli in presence of Zn(II), Cd(II), or Cu, and characterised by Electrospray Ionisation Mass Spectrometry and elemental analysis. C. gariepinus MT displays typical features of fish MTs, including 20 conserved cysteines, and seven bound divalent cations (Zn(II) or Cd(II)) when saturated. Livers from wild C. gariepinus fish collected in all three seasons from four different sites on the Kafue River of Zambia were analysed for their metal contents and for MT expression levels by quantitative PCR. Significant correlations were found between Zn and Cu levels and MT expression in livers, with MT expression clearly highest at the most polluted site, Chililabombwe, which is situated in the Copperbelt region. Based on our findings, hepatic expression of MT from C. gariepinus may be further developed as a major molecular biomarker of heavy metal pollution resulting from mining activities in this region. PMID:28718783