Erosion and physical transport via overland flow of arsenic and lead bound to silt-sized particles

PubMed Central

Cadwalader, G. Owen; Renshaw, Carl E.; Jackson, Brian P.; Magilligan, Francis J.; Landis, Joshua D.; Bostick, Benjamin C.

2011-01-01

Understanding of the transport mechanisms of contaminated soils and sediment is essential for the sustainable management of contaminated lands. In New England and elsewhere, vast areas of agricultural lands are contaminated by the historical application of lead-arsenate pesticides. Left undisturbed the physical and chemical mobility of As and Pb in these soils is limited due to their strong affinity for adsorption onto solid phases. However, soil disturbance promotes erosion and overland flow during intense rainstorms. Here we investigate the event-scale transport of disturbed As and Pb contaminated soils through measurement of concentrations of As and Pb in suspended sediment and changes in Pb isotopic ratios in overland flow. Investigation of several rain events shows that where land disturbance has occurred, physical transport of silt-sized particles and aggregates is the primary transport vector of As and Pb derived from pesticide-contaminated soil. Although both As and Pb are associated with similarly-sized particles, we find that solid-phase As is more effectively mobilized and transported than Pb. Our results demonstrate that anthropogenic land disturbance of historical lands contaminated with lead-arsenate pesticides may redistribute, through physical transport, significant amounts of As, and lesser amounts of Pb, to riparian and stream sediments, where they are potentially more bioavailable. PMID:21552357

Low Contribution of PbO2-Coated Lead Service Lines to Water Lead Contamination at the Tap

EPA Science Inventory

To determine if field experience corroborates that formation of stable PbO2 coatings on lead service lines (LSLs) provides an effective lead contamination control strategy, lead profile sampling was undertaken at eight home kitchen taps in three US cities (Newport, Rhode Island; ...

Combined application of compost and Bacillus sp. CIK-512 ameliorated the lead toxicity in radish by regulating the homeostasis of antioxidants and lead.

PubMed

Ahmad, Iftikhar; Akhtar, Muhammad Javed; Mehmood, Shehzad; Akhter, Kalsoom; Tahir, Muhammad; Saeed, Muhammad Farhan; Hussain, Muhammad Baqir; Hussain, Saddam

2018-02-01

Lead (Pb) contamination is ubiquitous and usually causes toxicity to plants. Nevertheless, application of compost and plant growth promoting rhizobacteria synergistically may ameliorate the Pb toxicity in radish. The present study assessed the effects of compost and Bacillus sp. CIK-512 on growth, physiology, antioxidants and uptake of Pb in contaminated soil and explored the possible mechanism for Pb phytotoxicity amelioration. Treatments comprised of un-inoculated control, compost, CIK-512, and compost + CIK-512; plants were grown in soil contaminated with Pb (500mgkg -1 ) and without Pb in pot culture. Lead caused reduction in shoot dry biomass, photosynthetic rate, stomatal conductance, relative water contents, whereas enhanced root dry biomass, ascorbate peroxidase, catalase, malondialdehyde and electrolyte leakage in comparison with non-contaminated control. Plants inoculated with strain CIK-512 and compost produced significantly higher dry biomass, photosynthetic rate and stomatal conductance in normal and contaminated soils. Bacterial strain CIK-512 and compost synergy improved growth and physiology of radish in contaminated soil possibly through homeostasis of antioxidant activities, reduced membrane leakage and Pb accumulation in shoot. Possibly, Pb-induced production of reactive oxygen species resulted in increased electrolyte leakage and malondialdehyde contents (r = 0.88-0.92), which led to reduction in growth (r = -0.97) and physiology (r = -0.38 to -0.80), however, such negative effects were ameliorated by the regulation of antioxidants (r = 0.78-0.87). The decreased activity of antioxidants coupled with Pb accumulation in aerial part of the radish indicates the Pb-phytotoxicity amelioration through synergistic application of compost and Bacillus sp. CIK-512. Copyright © 2017 Elsevier Inc. All rights reserved.

Alterations of lead speciation by sulfate from addition of flue gas desulfurization gypsum (FGDG) in two contaminated soils

EPA Science Inventory

This is the first study to evaluate the potential application of FGDG as an in situ Pb stabilizer in contaminated soils with two different compositions and to explain the underlying mechanisms. A smelter Pb contaminated soil (SM-soil), rich in ferrihydrite bound Pb (FH-Pb), ceru...

A 300 year history of lead contamination in northern French Alps reconstructed from distant lake sediment records.

PubMed

Arnaud, F; Revel-Rolland, M; Bosch, D; Winiarski, T; Desmet, M; Tribovillard, N; Givelet, N

2004-05-01

Lead concentrations and isotopic ratios were measured along two well-dated sediment cores from two distant lakes: Anterne (2100 m a.s.l.) and Le Bourget (270 m a.s.l.), submitted to low and high direct human impact and covering the last 250 and 600 years, respectively. The measurement of lead in old sediment samples (>3000 BP) permits, in using mixing-models, the determination of lead concentration, flux and isotopic composition of purely anthropogenic origin. We thus show that since ca. 1800 AD the regional increase in lead contamination was mostly driven by coal consumption ((206)Pb/(207)Pb approximately 1.17-1.19; (206)Pb/(204)Pb approximately 18.3-18.6), which peaks around 1915 AD. The increasing usage of leaded gasoline, introduced in the 1920s, was recorded in both lakes by increasing Pb concentrations and decreasing Pb isotope ratios. A peak around 1970 ((206)Pb/(207)Pb approximately 1.13-1.16; (206)Pb/(204)Pb approximately 17.6-18.0) corresponds to the worldwide recorded leaded gasoline maximum of consumption. The 1973 oil crisis is characterised by a drastic drop of lead fluxes in both lakes (from approximately 35 to <20 mg cm(-2) yr(-1)). In the late 1980s, environmental policies made the Lake Anterne flux drop to pre-1900 values (<10 mg cm(-2) yr(-1)) while Lake Le Bourget is always submitted to an important flux (approximately 25 mg cm(-2) yr(-1)). The good match of our distant records, together and with a previously established series in an ice core from Mont Blanc, provides confidence in the use of sediments as archives of lead contamination. The integration of the Mont Blanc ice core results from Rosman et al. with our data highlights, from 1990 onward, a decoupling in lead sources between the high elevation sites (Lake Anterne and Mont Blanc ice core), submitted to a mixture of long-distance and regional contamination and the low elevation site (Lake Le Bourget), where regional contamination is predominant.

Lead phytoremediation potential of Vetiver grass: a hydroponic study

NASA Astrophysics Data System (ADS)

Pachanoor, D. S.; Andra, S. P.; Datta, R.; Sarkar, D.

2006-05-01

Lead (Pb) is a toxic heavy metal that is released into the environment from a variety of sources. Sources of Pb contamination in soils can be divided into three broad categories: industrial activities, such as mining and smelting processes, agricultural activities, such as application of insecticide and municipal sewage sludge, and urban activities, such as use of Pb in gasoline, paints, and other materials. Severe Pb contamination of soils may cause a variety of environmental problems, including loss of vegetation, groundwater contamination and Pb toxicity in plants, animals and humans. The use of plants to remove toxic metals from soils (phytoremediation) is fast emerging as an acceptable strategy for cost-effective and environmentally sound remediation of contaminated soils. The objective of this study was to gain insight into the lead uptake potential and biochemical stress response mechanism in vetiver grass (Vetiveria zizanioides L.) upon exposure to Pb in contaminated soils. We investigated the effect of increasing concentrations of Pb on vetiver grass grown in a hydroponic system. Plant response to the addition of phosphate in the presence of Pb was also studied. Biochemical stress response was studied by monitoring the activities of Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes. The results indicated that exposure to Pb in the range of 0 ppm -1200 ppm had no significant negative effects on the growth of vetiver grass. There was no considerable decrease in vetiver biomass, implying the potential of this grass for Pb phytoremediation. The translocation of Pb from the root to the shoot was up to 20%. The SOD activity was in positive correlation with Pb concentrations in the solution, but no such trend was observed with GPx. In systems containing phosphate fertilizer, lead precipitated out immediately, thereby decreasing the soluble concentration of lead, resulting in less availability of Pb to the grass.

Environmental contaminants in California condors

USGS Publications Warehouse

Wiemeyer, Stanley N.; Scott, J.M.; Anderson, M.P.; Bloom, P.H.; Stafford, C.J.

1988-01-01

Five wild Califorinia condors (Gymnogyps californianus) that died in 1980-86 were necropsied and tissues were analyzed for environmental contaminants. Three died of lead (Pb) poisoning, 1 presumably of cyanide (CN) poisoning, and 1 nestling of handling shock. Organochlorine concentrations were low in 4 condors that were analyzed for these contaminants. Blood samples from 14 wild and 14 captive condors were analyzed primarily for Pb. Five of 14 wild condors sampled had elevated (> 0.70 ppm) concentrations of Pb in blood whereas Pb concentrations in all captive condors were low. Lead levels in individual birds often fluctuated over time. Lead exposure, especially poisoning, was a major factor affecting the wild California condor population during 1982-86. The probable source of Pb was bullet fragments in carrion on which condors were feeding.

The Effect of Soil Properties on Metal Bioavailability: Field Scale Validation to Support Regulatory Acceptance

DTIC Science & Technology

2014-06-01

unacceptable levels of the toxic metal(loid)s arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb). With the exception of Pb contaminated soils, human...remediation and closure. Lead (Pb), arsenic (As), chromium (Cr), and cadmium (Cd) are toxic (i.e., capable of producing an unwanted, deleterious effect...lagoon are contaminated with high concentrations of lead , chromium, and cadmium . 14 Deseret Chemical Depot: The Deseret Chemical Depot is

[Remediation Pb, Cd contaminated soil in lead-zinc mining areas by hydroxyapatite and potassium chloride composites].

PubMed

Wang, Li; Li, Yong-Hua; Ji, Yan-Fang; Yang, Lin-Sheng; Li, Hai-Rong; Zhang, Xiu-Wu; Yu, Jiang-Ping

2011-07-01

The composite agents containing potassium chloride (KCl) and Hydroxyapatite (HA) were used to remediate the lead and cadmium contaminated soil in Fenghuang lead-zinc mining-smelting areas, Hunan province. The objective of this study was to identify and evaluate the influence of Cl- to the fixing efficiency of Pb and Cd by HA. Two types of contaminated soil (HF-1, HF-2) were chosen and forty treatments were set by five different Hydroxyapatite (HA) dosages and four different Cl- dosages. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the results. It showed that HA could efficiently fix the Pb and Cd from TCLP form. The maximum Pb-fixing efficiency and Cd-fixing efficiency of two types of soil were 83.3%, 97.27% and 35.96%, 57.82% when the HA: Pb: KCl molar ratio was 8: 1: 2. Compared to the fixing efficiency without KCl, KCl at the KCl: Pb molar ratio of 2 improved Pb-fixing efficiency and Cd-fixing efficiency by 6.26%, 0.33% and 7.74%, 0.83% respectively when the HA: Pb molar ratio was 8. Generally, Cl- can improve the Pb/Cd-fixing efficiency in heavy metal contaminated soil by Hydroxyapatite.

Distribution and Source Identification of Pb Contamination in industrial soil

NASA Astrophysics Data System (ADS)

Ko, M. S.

2017-12-01

INTRODUCTION Lead (Pb) is toxic element that induce neurotoxic effect to human, because competition of Pb and Ca in nerve system. Lead is classified as a chalophile element and galena (PbS) is the major mineral. Although the Pb is not an abundant element in nature, various anthropogenic source has been enhanced Pb enrichment in the environment after the Industrial Revolution. The representative anthropogenic sources are batteries, paint, mining, smelting, and combustion of fossil fuel. Isotope analysis widely used to identify the Pb contamination source. The Pb has four stable isotopes that are 208Pb, 207Pb, 206Pb, and 204Pb in natural. The Pb is stable isotope and the ratios maintain during physical and chemical fractionation. Therefore, variations of Pb isotope abundance and relative ratios could imply the certain Pb contamination source. In this study, distributions and isotope ratios of Pb in industrial soil were used to identify the Pb contamination source and dispersion pathways. MATERIALS AND METHODS Soil samples were collected at depth 0­-6 m from an industrial area in Korea. The collected soil samples were dried and sieved under 2 mm. Soil pH, aqua-regia digestion and TCLP carried out using sieved soil sample. The isotope analysis was carried out to determine the abundance of Pb isotope. RESULTS AND DISCUSSION The study area was developed land for promotion of industrial facilities. The study area was forest in 1980, and the satellite image show the alterations of land use with time. The variations of land use imply the possibilities of bringing in external contaminated soil. The Pb concentrations in core samples revealed higher in lower soil compare with top soil. Especially, 4 m soil sample show highest Pb concentrations that are approximately 1500 mg/kg. This result indicated that certain Pb source existed at 4 m depth. CONCLUSIONS This study investigated the distribution and source identification of Pb in industrial soil. The land use and Pb concentration at depth indicated elusive contamination event or contamination sources. In order to identify the contamination source clearly, isotope and Pb compound/mineralogy analysis are necessary.

Applying geochemical signatures of atmospheric dust to distinguish current mine emissions from legacy sources

NASA Astrophysics Data System (ADS)

Dong, Chenyin; Taylor, Mark Patrick

2017-07-01

Resolving the source of environmental contamination is the critical first step in remediation and exposure prevention. Australia's oldest silver-zinc-lead mine at Broken Hill (>130 years old) has generated a legacy of contamination and is associated with persistent elevated childhood blood lead (Pb) levels. However, the source of environmental Pb remains in dispute: current mine emissions; remobilized mine-legacy lead in soils and dusts; and natural lead from geological weathering of the gossan ore body. Multiple lines of evidence used to resolve this conundrum at Broken Hill include spatial and temporal variations in dust Pb concentrations and bioaccessibility, Pb isotopic compositions, particle morphology and mineralogy. Total dust Pb loading (mean 255 μg/m2/day) and its bioaccessibility (mean 75% of total Pb) is greatest adjacent to the active mining operations. Unweathered galena (PbS) found in contemporary dust deposits contrast markedly to Pb-bearing particles from mine-tailings and weathered gossan samples. Contemporary dust particles were more angular, had higher sulfur content and had little or no iron and manganese. Dust adjacent to the mine has Pb isotopic compositions (208Pb/207Pb: 2.3197; 206Pb/207Pb: 1.0406) that are a close match (99%) to the ore body with values slightly lower (94%) at the edge of the city. The weight of evidence supports the conclusion that contemporary dust Pb contamination in Broken Hill is sourced primarily from current mining activities and not from weathering or legacy sources.

Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA

USGS Publications Warehouse

Jackson, B.P.; Winger, P.V.; Lasier, P.J.

2004-01-01

'Capsule:' Coal combustion emissions appear to be a major source of Pb in the Okefenokee wetland. Contamination of the environment from atmospheric deposition during the twentieth century is pervasive even in areas ostensibly considered pristine or remote from point sources. In this study, Pb concentrations in a Pb-210-dated peat core collected from the Okefenokee Swamp, GA were used to assess historical contaminant input via atmospheric deposition. Lead isotope ratios were determined by dynamic reaction cell ICP-MS (DRC-ICP-MS). Increases in Pb concentration occurred in the late nineteenth century and a marked rise in Pb concentrations pre-dated the widespread use of leaded gasoline within the US. The Pb-206/Pb-207 ratios of 1.19 during this period were consistent with coal combustion emissions. A later increase in Pb concentration, concurrent with a trend toward more radiogenic Pb-206/Pb-207 ratios in gasoline is consistent with an increased input of Pb from leaded gasoline emissions. However, it appears that coal combustion emissions remain a major source of Pb to the Okefenokee.

Lead Retention in a Calcareous Soil Influenced by Calcium and Phosphate Amendments

EPA Science Inventory

Phosphate amendments in calcareous lead (Pb)-contaminated soils to immobilize Pb may be hindered due to competition of Pb with calcium (Ca) that may inhibit the retention of Pb as a precipitation mechanism. This study explored the retention of Pb in a calcareous soil spiked and ...

Lead in roadway dusts from different functional areas in a typical valley city, NW China: contamination and exposure risk.

PubMed

Pan, Huiyun; Lu, Xinwei; Lei, Kai

2018-01-01

Lead contamination and exposure risk assessment in roadway dusts from four different functional areas in a typical valley city in northwest China (Xi'an) were conducted in this study. A total of 130 roadway dust samples from park area (PA), traffic area (TA), educational area (EA), and residential area (RA) were collected and Pb concentrations in the samples were determined by using XRF (X-ray fluorescence). Geo-accumulation index (I geo ) and enrichment factor (EF) were applied to assess Pb contamination level and the hazard indexes (HI) of Pb were calculated to evaluate the exposure risks to children and adults. The results showed that roadway dusts from all four functional areas had elevated Pb concentrations and pollution characteristics of Pb were discrepant in different functional areas. The mean concentration of Pb in roadway dusts from PA, TA, EA, and RA was 147.4, 74.8, 119.6, and 161.0 mg kg -1 , respectively. The I geo and EF of Pb were mostly 1-3 and 2-20, which indicated moderate to high Pb contamination in roadway dusts. High contamination level of Pb in RA and EA should receive priority for prevention and control. Exposure risk assessment of Pb from roadway dusts was mainly in the acceptable range, but the potential risk of Pb exposure to children should be continuously concerned.

Influence of the sediment on lead speciation in the Tagus estuary.

PubMed

Mota, A M; Cruz, P; Vilhena, C; Gonçalves, M L S

2005-04-01

The aim of this work is to study the influence of the Tagus estuarine sediment on lead speciation in the overlying natural water. The water sample in the presence of the sediment was contaminated three times with Pb(II) in a laboratory experiment. In different periods of time, at 1-7 days after each contamination, small volumes of water were titrated with lead. The titration was followed by anodic stripping voltammetry in differential pulse mode. Before and after contamination systematic analysis of the voltammetric parameters (peak current, peak potential and peak width) were carried out to get a clear picture of Pb(II) complexation in the soluble fraction in contact with the sediment. Two main types of organic ligands, macromolecular ligands and small compounds, were detected before contamination. Both of them form labile complexes (degree of lability within the timescale of some milliseconds). The small compounds, with a diffusion coefficient similar to that of the free metal ion, present a homogeneous behaviour in terms of Pb complexation. On the other hand macromolecular ligands, with a diffusion coefficient of 1.2 x 10(-6) cm2s(-1), can be described by two different binding groups, which might be of phenolic and carboxylic type as presented by humic matter. The sediment eliminated lead contamination (10(-6) moldm(-3) was the maximum concentration added) from 12 dm3 of water (surface of 8 dm2) within 2 days. It was also found that the sediment released organic ligands responsible for both labile and inert Pb complexes "seen" by voltammetry. The release of organic ligands that decreases the bioavailability of Pb(II) was clearly detected 1 week after contamination. Therefore, the sediment acts as a buffer for lead through two mechanisms against lead contamination: removing lead ions from the solution and releasing organic ligands to the water column. In a short period of time the sediment responds as a self-cleaning system for Pb(II) contamination in the estuarine water, which may have a very important influence in environmental pollution.

Lead distribution and its potential risk to the environment: lesson learned from environmental monitoring of abandon mine.

PubMed

Nobuntou, Wanida; Parkpian, Preeda; Oanh, Nguyen Thi Kim; Noomhorm, Athapol; Delaune, R D; Jugsujinda, Aroon

2010-11-01

There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities. To better understand current status of Pb contamination and accumulation in the surrounding environment and potential health impact, surface sediment, soil and plant samples were collected seasonally from representative monitoring sites along the aquatic track or flow regime. Potential health risk was determined using hazard quotient (HQ) as an index for local inhabitants who consume rice. Environmental monitoring illustrated that Pb concentrations in the surface sediment was as high as 869.4 mg kg(-1) dry weight and varied differently among stations sampled. Lead content in agricultural soil ranged between 137.8 to 613.5 mg kg(-1) dry weight and was inversely proportion to the distance from the point source. Moreover Pb was transported from the point source to down hill areas. At the highly polluted monitoring stations (S1, S2, and S3), concentrations of Pb exceeded the maximum allowable concentration for Pb in agricultural soil (300 mg kg(-1)) by 1.7-2 times. The Pb in soil was primarily associated with Fe/Mn oxides bound fraction (46-56%) followed by the organic bound fraction (25-30%). Lead uptake by plant varied and was species dependent. However root and tuber crops like cassava (19.92 mg Pb kg(-1) dry weight) and curcumin (3.25 mg Pb kg(-1) dry weight) could have removed Pb from the soil which suggest growing root crops in Pb contaminated soils should be avoided. However Cd, a co-contaminant at one of monitored stations (S4) yielded rice grain with Cd exceeding the maximum allowable concentration suggesting some potential health risk (HQ = 5.34) if people consume rice grown at this station. Overall result shows a low risk associated with Pb release into the environment.

In Situ Formation of Pyromorphite Is Not Required for the Reduction of in Vivo Pb Relative Bioavailability in Contaminated Soils

EPA Science Inventory

The effect of phosphate treatment on lead relative bioavailability (Pb RBA) was assessed in three distinct Pb-contaminated soils. Phosphoric acid (PA) or rock phosphate were added to smelter (PP2), nonferrous slag (SH15), and shooting range (SR01) impacted soils at a P:Pb molar ...

Screening and assessment of solidification/stabilization amendments suitable for soils of lead-acid battery contaminated site.

PubMed

Zhang, Zhuo; Guo, Guanlin; Teng, Yanguo; Wang, Jinsheng; Rhee, Jae Seong; Wang, Sen; Li, Fasheng

2015-05-15

Lead exposure via ingestion of soil and dust generally occurs at lead-acid battery manufacturing and recycling sites. Screening solidification/stabilization (S/S) amendments suitable for lead contaminated soil in an abandoned lead-acid battery factory site was conducted based on its chemical forms and environmental risks. Twelve amendments were used to immobilize the Pb in soil and assess the solidification/stabilization efficiency by toxicity leaching tests. The results indicated that three amendments, KH₂PO₄ (KP), KH₂PO₄:oyster shell power=1:1 (by mass ratio; SPP), and KH₂PO₄:sintered magnesia=1:1 (by mass ratio; KPM) had higher remediation efficiencies that led to a 92% reduction in leachable Pb with the addition of 5% amendments, while the acid soluble fraction of Pb (AS-Pb) decreased by 41-46% and the residual fraction (RS-Pb) increased by 16-25%. The S/S costs of the three selected amendments KP, SPP, and KPM could be controlled to $22.3 per ton of soil when the Pb concentration in soil ranged from 2000 to 3000 mg/kg. The results of this study demonstrated that KP, SPP, and KPM can effectively decrease bioavailability of Pb. These findings could provide basis for decision-making of S/S remediation of lead-acid battery contaminated sites. Copyright © 2015 Elsevier B.V. All rights reserved.

Lead isotope ratios in bone ash of blesbok (Damaliscus pygargus phillipsi): a means of screening for the accumulation of contaminants from uraniferous rocks.

PubMed

Nöthling, Johan O; Du Toit, Johannes S; Myburgh, Jan G

2014-09-19

This study was done to determine whether blesbok (Damaliscus pygargus phillipsi) from the Krugersdorp Game Reserve (KGR) in Gauteng Province, South Africa have higher concentrations of (238)U and higher (206)Pb/(204)Pb and (207)Pb/(204)Pb ratios in their bone ash than blesbok from a nearby control reserve that is not exposed to mine water and has no outcrops of uraniferous rocks. Eight blesbok females from the KGR and seven from the control site, all killed with a brain shot, were used. A Thermo X-series 2 quadrupole ICPMS was used to measure the concentrations of (238)U and lead and a Nu Instruments NuPlasma HR MC-ICP-MS to measure the lead isotope ratios in the tibial ash from each animal. KGR blesbok had higher mean concentrations of (238)U (P = 0.02) and ratios of (206)Pb/(204)Pb and (207)Pb/(204)Pb (P < 0.00001) than the control blesbok. The probability of rejecting the false null hypothesis of no difference in the (206)Pb/(204)Pb or (207)Pb/(204)Pb ratios between KGR and control reserve animals (the power of the test) was 0.999. The blesbok from the KGR accumulated contaminants from an uraniferous environment. The (206)Pb/(204)Pb and (207)Pb/(204)Pb ratios in tibial ash proved effective in confirming accumulation of contaminants from uraniferous rocks.

Concentration trends for lead and calcium-normalized lead in fish fillets from the Big River, a mining-contaminated stream in southeastern Missouri USA

USGS Publications Warehouse

Schmitt, Christopher J.; McKee, Michael J.

2016-01-01

Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005–2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005–2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

Concentration Trends for Lead and Calcium-Normalized Lead in Fish Fillets from the Big River, a Mining-Contaminated Stream in Southeastern Missouri USA.

PubMed

Schmitt, Christopher J; McKee, Michael J

2016-11-01

Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005-2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005-2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

AMENDING SOILS WITH PHOSPHATE AS MEANS TO MITIGATE SOIL LEAD HAZARD: A CRITICAL REVIEW OF THE STATE OF THE SCIENCE

EPA Science Inventory

Ingested soil and surface dust may be important contributors to elevated blood lead (Pb) levels in children exposed to Pb contaminated environments. Mitigation strategies have typically focused on excavation and removal of the contaminated soil. However, this is not always feas...

Remediation of lead contaminated soil by biochar-supported nano-hydroxyapatite.

PubMed

Yang, Zhangmei; Fang, Zhanqiang; Zheng, Liuchun; Cheng, Wen; Tsang, Pokeung Eric; Fang, Jianzhang; Zhao, Dongye

2016-10-01

In this study, a high efficiency and low cost biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in the remediation of lead (Pb)-contaminated soil. The remediation effect of nHAP@BC on Pb-contaminated soil was evaluated through batch experiments. The stability, bioaccessibility of Pb in the soil and the change in soil characteristics are discussed. Furthermore, the effects of the amendments on the growth of cabbage mustard seedlings and the accumulation of Pb were studied. The results showed that the immobilization rates of Pb in the soil were 71.9% and 56.8%, respectively, after a 28 day remediation using 8% nHAP and nHAP@BC materials, and the unit immobilization amount of nHAP@BC was 5.6 times that of nHAP, indicating that nHAP@BC can greatly reduce the cost of remediation of Pb in soil. After the nHAP@BC remediation, the residual fraction Pb increased by 61.4%, which greatly reduced the bioaccessibility of Pb in the soil. Moreover, nHAP@BC could effectively reduce the accumulation of Pb in plants by 31.4%. Overall, nHAP@BC can effectively remediate Pb-contaminated soil and accelerate the recovery of soil fertility. Copyright © 2016 Elsevier Inc. All rights reserved.

Omaha Soil Mixing Study: Redistribution of Lead in ...

EPA Pesticide Factsheets

Urban soils within the Omaha Lead Superfund Site have been contaminated with lead (Pb) from atmospheric deposition of particulate materials from lead smelting and recycling activities. In May of 2009 the Final Record of Decision stated that any residential soil exceeding the preliminary remediation goal (PRG; 400 mgPb kg-1soil) would be excavated, backfilled and re-vegetated. The remedial action entailed excavating contaminated soil in the top 12 inches and excavation could stop when the concentration of soil Pb was less than 400 mg kg-1 in the top 12 inches, or less than 1200 mg kg-1 at depths greater than 1 ft. After removal of the contaminated soil, clean backfill was applied and a grass lawn was replanted. A depth of 12 inches was based on the assumption that Pb-contaminated soil at depth greater than 1 ft would not represent a future risk (ASTDR Health Consult, 2004). This assumption was based on the principal that mixing and other factors encountered during normal excavation practices would not result in Pb surface concentrations greater than the PRG. The goal of the current study was to investigate the redistribution of Pb in remediated residential surface soils after typical homeowner earth-disturbing activities in the OLS Site. Of specific interest to the region for protection of human health is determining whether soil mixing associated with normal homeowner excavation practices results in surface Pb concentrations greater than the preliminary r

Effect of Ag and Pb Addition on Microstructural and Mechanical Properties of SAC 105 Solders

NASA Astrophysics Data System (ADS)

Molnar, Aliz; Janovszky, Dora; Kardos, Ibolya; Molnar, Istvan; Gacsi, Zoltan

2015-10-01

Melting and crystallization processes of lead-free and lead-contaminated alloys in near-equilibrium state were investigated. In addition, the effect of silver content up to 4 wt.% on the microstructure of Sn-Ag-Cu alloys was studied. The volume fraction of β-Sn decreased by half owing to 4 wt.% Ag content. Furthermore, contamination by lead strongly influences the properties of the solidified microstructure. The Pb grains appear as a result of two processes when the Pb content is equal to 0.5 wt.% or higher: Pb phase solidifies in the quaternary eutectic at 176°C, and Pb grains precipitate from the primary β-Sn solid solution grain during a solid state reaction. The freezing range enlarges to 51°C due to 2 wt.% Pb content owing to quaternary eutectic. Above 1 wt.% Pb content, the mechanical properties also improve due to grains of quaternary eutectic Pb and precipitated Pb grains with a size <1 μm.

Long-term (1992-2004) record of lead, cadmium, and zinc air contamination in Warsaw, Poland: determination by chemical analysis of moss bags and leaves of Crimean linden.

PubMed

Dmuchowski, Wojciech; Bytnerowicz, Andrzej

2009-12-01

Between 1992 and 2004, air contamination with lead (Pb), cadmium (Cd), and zinc (Zn) in Warsaw, Poland, was monitored annually with moss (Sphagnum fallax) bags on a network of 230 sites covering the entire city. During the study the highest contamination was near the Warszawa Steel Mill, northwestern Warsaw. Lead concentrations in moss bags decreased in time, while those of Cd and Zn did not show clear trends. Between 1994 and 2004, Pb, Cd, and Zn were also monitored in the Crimean linden (Tilia Euchlora) foliage along the main city avenue and in a northwestern warsaw park. Lead concentrations decreased more near the avenue than in the park, indicating that the phasing-out of leaded gasoline had a major effect on reduced Pb contamination in Warsaw. At the same time, foliar concentrations of Cd and Zn in both areas decreased much less.

Review of pollutant lead decline in urban air and human blood: A case study from northwestern Europe

NASA Astrophysics Data System (ADS)

Petit, Daniel; Véron, Alain; Flament, Pascal; Deboudt, Karine; Poirier, André

2015-09-01

A review of the transient decline of pollutant lead in the air (PbA) and the blood (PbB) has been conducted in order to assess the relationship between these environmental reservoirs. We have demonstrated that PbA decreased 20 to 100 times more than PbB for the past 30 years, suggesting another significant intake besides airborne lead to explain lead accumulated in humans. This trend has also been observed in two blood surveys we have completed in 1976-1978 and 2008-2009 in northern France and Belgium. Nowadays, the mean PbB (1.5-3.5 μg/dL) remains at least 100 times higher than the estimated non-contaminated PbB. Lead isotope imprints in blood could help decipher specific contamination cases, and were coherent with the decline of PbA, but could not help discriminate the source of blood lead owing to the lack of source imprints, especially from dietary intakes. Correlations between recent PbB, isotopic imprints and the age of the subjects suggested that lead released from bones has become a significant source of lead in blood. The significant cause for human exposure to lead may have shifted from direct pollutant lead input accumulated in exogenous reservoirs (air and diet) to endogenous lead release from bone tissues consequential to metabolic calcium homeostasis and bone turnover.

INFLUENCE OF AGING ON PYROMORPHITE FORMATION AND DISSOLUTION

EPA Science Inventory

Published literature has clearly demonstrated that the reaction of a lead (Pb) source as either Pb-minerals (angelesite, cerrusite, or galena), goethite adsorbed lead, Pb-contaminated soils, or an in-vitro bioavailable assay with a phosphate reserve (apatite or hydroxyapatite) re...

Zinc Speciation in Proximity to Phosphate Application Points in a Lead/Zinc Smelter-Contaminated Soil

EPA Science Inventory

The use of P to immobilize Pb in contaminated soils has been well documented. However, the influence of P on Zn speciation in soils has not been extensively examined, and these two metals often occur as co-contaminants. We hypothesized that additions of P to a Pb/Zn-contaminate...

A Millennial-Scale Record of Mercury and Lead Contamination in Peatlands of the Sacramento-San Joaquin Delta of California

NASA Astrophysics Data System (ADS)

Drexler, J. Z.; Alpers, C. N.; Neymark, L. A.; Paces, J. B.; Fuller, C.

2015-12-01

Peat cores from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California (the landward end of the San Francisco Estuary) were used to track the onset of anthropogenic pollution on the west coast of the United States. Cores were sectioned into 2-cm depth intervals and analyzed for lead (Pb), mercury (Hg), and titanium (Ti) concentrations and Pb isotope compositions. Peat profiles were dated using radiocarbon, 210Pb, and 137Cs. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 μg g-1and from 6.9 to 71 ng g-1, respectively. For much of the past 6,000+ years, the Delta was free from anthropogenic pollution; however, beginning in ~1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by mining and smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850 CE), when concentrations reached their highest levels (74 μg g-1 Pb, 990 ng g-1 Hg; PbEF = 12 and HgEF = 28). Pb concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall the results show that the Delta was a pristine region for most of its ~6,700-year existence; however, since ~1425 CE, it has received Pb and Hg contamination from both global and regional sources. This study demonstrates that micro-tidal peatlands can be a highly useful archive for establishing the onset of anthropogenic contamination and chronicling the transition from a pristine to a polluted landscape.

RISK ASSESSMENT AND REMEDIATION OF SOILS CONTAMINATED BY MINING AND SMELTING OF LEAD, ZINC AND CADMIUM

EPA Science Inventory

Mining nd smelting of Pb, Zn and Cd ores have caused widespread soil contamination in many countries. In locations with severe soil contamination, and strongly acidic soil or mine waste, ecosystems are devastated. Research has shown that An phytotoxicity, Pb-induced phosphate def...

LINKING SOLID PHASE SPECIATION OF PB SEQUESTERED TO BIRNESSITE TO ORAL PB BIOACCESSIBLITY: IMPLICATIONS FOR SOIL REMEDIATION

EPA Science Inventory

Lead (Pb) sorption onto oxide surfaces in soils may strongly influence the risk posed from incidental ingestion of lead-contaminated soils. In this study, Pb was sorbed to a model soil mineral, birnessite, and was placed in a simulated gastrointestinal tract (in vitro) to simula...

Quality Assurance Project Plan For Verification of ANDalyze Lead100 Test Kit and AND1000 Fluorimeter

EPA Science Inventory

Lead (Pb) is a naturally occurring metal in the aquatic environment; however, most Pb contamination of concern arises from anthropogenic sources (such as deposition of Pb dust from combustion processes in natural waterways or due to its use in plumbing materials). Although Pb is...

Lead contamination in sediments in the past 20 years: A challenge for China.

PubMed

Han, Lanfang; Gao, Bo; Hao, Hong; Zhou, Huaidong; Lu, Jin; Sun, Ke

2018-06-04

Lead (Pb) contamination was recognized in China early in the 1920s. However, the response of Pb contamination in sediments to China's rapid economic and social development remains uncertain to date. We conducted a literature review of over 1000 articles from 1990 to 2016 and the first national-scale survey of Pb contamination in China. A literature review showed that available research in China focused on the economically highly developed river basins, including the Pearl River Basin (PRB), Yellow River Basin (YRB), and Yangtze River Basin (YtRB), whereas those in the less developed southeastern, southwestern, and northwestern river basins received limited attention. The YtRB and YRB had higher Pb contamination levels than other basins, corresponding with the rapid economic development in those regions. However, the less economically developed river basins in the southeastern and northwestern regions of China were also contaminated by Pb. Analysis of 146 studies in the PRB, YRB, and YtRB revealed that Pb contamination in PRB sediments showed a tendency to improve over time, whereas that from the YtRB exhibited a tendency to worsen. For the YRB, there was a slight increase from 1990 to 2006 and a decreasing trend from 2007 to 2014. The overall temporal trend in Pb levels in PRB and YRB sediments corresponded with that of the Pb discharged in wastewater in the surrounding cities, indicating that industrial wastewater discharge was possibly one of the main anthropogenic sources of Pb in those sediments. For the YtRB, the increasing trend in Pb concentrations was related to the considerably high atmospheric Pb emissions in the surrounding cities and its geographical characteristics. These findings suggested that China should develop systematic and consistent approaches for monitoring Pb contents in sediments and adopt a regional economic development policy focusing on pollution prevention. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Taylor, Mark Patrick, E-mail: mark.taylor@mq.edu.au; Mould, Simon Anthony; Kristensen, Louise Jane

Although blood lead values in children are predominantly falling globally, there are locations where lead exposure remains a persistent problem. One such location is Broken Hill, Australia, where the percentage of blood lead values >10 μg/dL in children aged 1–4 years has risen from 12.6% (2010), to 13% (2011) to 21% (2012). The purpose of this study was to determine the extent of metal contamination in places accessible to children. This study examines contemporary exposure risks from arsenic, cadmium, lead, silver and zinc in surface soil and dust, and in pre- and post-play hand wipes at six playgrounds across Brokenmore » Hill over a 5-day period in September 2013. Soil lead (mean 2,450 mg/kg) and zinc (mean 3,710 mg/kg) were the most elevated metals in playgrounds. Surface dust lead concentrations were consistently elevated (mean 27,500 μg/m{sup 2}) with the highest lead in surface dust (59,900 μg/m{sup 2}) and post-play hand wipes (60,900 μg/m{sup 2}) recorded close to existing mining operations. Surface and post-play hand wipe dust values exceeded national guidelines for lead and international benchmarks for arsenic, cadmium and lead. Lead isotopic compositions ({sup 206}Pb/{sup 207}Pb, {sup 208}Pb/{sup 207}Pb) of surface dust wipes from the playgrounds revealed the source of lead contamination to be indistinct from the local Broken Hill ore body. The data suggest frequent, cumulative and ongoing mine-derived dust metal contamination poses a serious risk of harm to children. - Highlights: 1.Playground soils and surface dust in a mining town have high metal concentrations. 2.Elevated levels of As, Cd, Pb and Zn dust are found on playground users′ hands. 3.Pb isotope analysis shows that the source of playground dust is ore body Pb. 4.Surface mine operations must be contained to reduce childhood lead exposure risks. 5.Mine environmental licences need to set trigger values for As, Cd, Pb and Zn dust.« less

Pyrolysis of Plants After Phytoremediation of Contaminated Soil with Lead, Cadmium and Zinc.

PubMed

Özkan, Aysun; Günkaya, Zerrin; Banar, Müfide

2016-03-01

The aim of this study was to remediate lead (Pb), cadmium (Cd) and zinc (Zn) from contaminated soil and stabilize to pyrolysis solid product. To accomplish this, phytoremediation of soil contaminated with Pb, Cd and Zn by different plants (sunflower, corn and rape) was performed with and without ethylenediaminetetraacetic acid (EDTA). According to phytoremediation results, rape was the most effective plant with 72 %, 76 % and 77 % removal efficiency for Pb, Cd and Zn, respectively. Also, EDTA addition had no significant effect on translocation of the metals from roots to stems. According to pyrolysis results, Pb, Cd and Zn in the contaminated plants were stabilized in the ash/char fraction. In addition, the solid product can be safely landfilled as inert waste since its toxicity leaching value is lower than the limit values given in the Turkish Regulation on Landfilling of Wastes.

Bioaccessibility tests accurately estimate bioavailability of lead to quail

USGS Publications Warehouse

Beyer, W. Nelson; Basta, Nicholas T; Chaney, Rufus L.; Henry, Paula F.; Mosby, David; Rattner, Barnett A.; Scheckel, Kirk G.; Sprague, Dan; Weber, John

2016-01-01

Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with phosphorus significantly reduced the bioavailability of Pb. Bioaccessibility of Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter (24%), or present as Pb sulfate (18%). Additional Pb was associated with P (chloropyromorphite, hydroxypyromorphite and tertiary Pb phosphate), and with Pb carbonates, leadhillite (a lead sulfate carbonate hydroxide), and Pb sulfide. The formation of chloropyromorphite reduced the bioavailability of Pb and the amendment of Pb-contaminated soils with P may be a thermodynamically favored means to sequester Pb.

Lead contamination of the Seine River, France: geochemical implications of a historical perspective.

PubMed

Ayrault, Sophie; Roy-Barman, Matthieu; Le Cloarec, Marie-Françoise; Priadi, Cindy Rianti; Bonté, Philippe; Göpel, Christa

2012-05-01

Four sediment cores collected in the Seine River basin and dated between 1916 and 2003 were analyzed for lead concentrations and isotopic composition. In all four cores, the measured Pb concentration (up to 460 mg kg(-1)) lies significantly above the natural background (27-40 mg kg(-1)), although a significant decrease (down to 75 mg kg(-1)) was observed during the second half of the 20th century which can be explained by the reduction of lead emissions. The (206)Pb/(207)Pb ratio measured in these samples indicates that the main source of Pb used in the Paris conurbation is characterized by a "Rio Tinto" signature (defined as (206)Pb/(207)Pb=1.1634 ± 0.0001). A high contribution, up to 25%, from the leaded gasoline (characterized by (206)Pb/(207)Pb=1.08 ± 0.02) is revealed in the Seine River downstream Paris, indicating that lead from the leaded gasoline is preferentially released to the river. The dominating Pb signature in the Paris conurbation that is currently sampled through incinerators fumes ((206)Pb/(207)Pb=1.1550 ± 0.0005) and waste water treatment plant ((206)Pb/(207)Pb=1.154 ± 0.002), represents a mixture of highly recycled lead from the Rio Tinto mine and lead from leaded gasoline (imprinted by the low (206)Pb/(207)Pb of the Broken Hill mine). This signature is called "urban" rather than "industrial", because it is clearly distinct from the Pb that is found in areas contaminated by heavy industry, i.e. the heavy industries located on the Oise River which used lead from European ores characterized by high (206)Pb/(207)Pb ratios (~1.18-1.19) and possibly a minor amount of North American lead ((206)Pb/(207)Pb ratios>1.20). The "urban" signature is also found in a rural area upstream of Paris in the 1970's. At the Seine River mouth in 2003, Pb with an urban signature represents 70% of the total Pb sediment content, with the 30% remaining corresponding to natural Pb. Copyright © 2012 Elsevier Ltd. All rights reserved.

Experimental lead toxicosis in ponies: comparison of the effects of smelter effluent-contaminated hay and lead acetate

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

Burrows, G.E.; Borchard, R.E.

1982-12-01

Grass hay produced in the Coeur d'Alene River Basin of northern Idaho was fed to a group of 4 ponies. The hay contained Pb in concentration of 423 +/- 82 mg/kg and Cd in concentration of 10.8 +/- 1.4 mg/kg, resulting in daily exposures of the ponies to approximately 7.4 mg of Pb/kg and 0.19 mg of Cd/kg/day. The results in this group of ponies were compared with those from a group fed noncontaminated grass hay and given a daily dose of 10 mg of Pb/kg of body weight, in the form of lead acetate. Clinical toxicologic signs, hematologic changes,more » and blood and tissue Pb concentrations were similar in the 2 groups. However, the severity of the disease process appeared to be greater in the ponies fed the Pb- and Cd-contaminated hay. This was shown clearly by the shorter interval between onset of clinical changes and death in the ponies fed contaminated hay. The possibility of multiple heavy metal effects is discussed. Clinical toxicologic signs observed include incoordination, labial paresis, pharyngeal paresis, CNS depression, anorexia, and body weight loss. Anemia or marginal anemia was common and was often accompanied by the appearance of nucleated RBC and Howell-Jolly bodies in peripheral blood. Neither the hematologic response nor the blood Pb concentrations were reflective of the severity of poisoning, although blood Pb concentrations were greater than 0.35 micrograms/ml once clinical signs of toxicity were observed. Liver, kidney, spleen, brain, and bone Pb concentrations and liver, kidney, and brain Cd concentrations were increased in both the ponies fed contaminated hay and the ponies given lead acetate.« less

Innovative solidification/stabilization of lead contaminated soil using incineration sewage sludge ash.

PubMed

Li, Jiangshan; Poon, Chi Sun

2017-04-01

The proper treatment of lead (Pb) contaminated soils and incinerated sewage sludge ash (ISSA) has become an environmental concern. In this study, ordinary Portland cement (OPC) and blended OPC containing incinerated sewage sludge ash (ISSA) were used to solidify/stabilize (S/S) soils contaminated with different concentrations of Pb. After curing for 7 and 28 d, the S/S soils were subjected to a series of strength, leaching and microscopic tests. The results showed that replacement of OPC by ISSA significantly reduced the unconfined compressive strength (UCS) of S/S soils and leached Pb. In addition, the leaching of Pb from the monolithic samples was diffusion controlled, and increasing the ISSA addition in the samples led to a lower diffusion coefficient and thus an increase in the feasibility for "controlled utilization" of S/S soils. Furthermore, the proposed S/S method significantly decreased the amount of Pb associated with carbonates and increased the amount of organic and residual Pb in S/S soils, reflecting that the risk of Pb contaminated soils can be effectively mitigated by the incorporating of ISSA. Overall, the leachability of Pb was controlled by the combined effect of adsorption, encapsulation or precipitation in the S/S soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recovering lead from cupel waste generated in gold analysis by Pb-Fire assay.

PubMed

Cerceau, Cristiane Isaac; Carvalho, Cornélio de Freitas; Rabelo, Ana Carolina Silveira; Dos Santos, Cláudio Gouvea; Gonçalves, Sabrina Mayra Dias; Varejão, Eduardo Vinícius Vieira

2016-12-01

Because of its precision and accuracy, Pb-Fire assay is the most employed method for gold analysis in geological materials. At the second stage of the method, namely cupellation, lead is oxidized to PbO which is absorbed by the cupel, leading to metallic gold as a tiny bend at the bottom of the recipient. After cupellation, cupel becomes highly contaminated with lead, making its disposal a serious risk of environmental contamination. In the present work, a leaching process for removing lead from cupel waste is proposed, which allowed for removing 96% of PbO by weight. After a precipitation step, 92.0% of lead was recovered from leachates in the form of PbSO 4 . Lead in the solid wastes left by the extraction was above the limit established by Brazilian legislation and these were classified as non-hazardous. Finally, secondary effluents generated after the precipitation step presented lead content more than twenty times lower than that of leachates from cupel waste. Tons of cupel waste are annually generated from gold analysis by Pb-Fire assay. Thus, the proposed method can contribute to prevent the discharge of high amounts of lead into the environment. Also, recovery of lead can help to partially meet the industrial demand for lead compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

EFFECT OF SOIL PB INACTIVATION TREATMENTS ON BIOAVAILABILITY OF JOPLIN, MO, SMELTER CONTAMINATED SOIL PB TO RATS

EPA Science Inventory

The effects of treating contaminated soils with various soil amendments on the bioavailability of lead were assessed in the weanling rat model. The effect of treatment was assessed by comparing the adsorption of Pb of animals fed soil samples treated with (0.5%, 1% P and 2.5% Fe ...

Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring

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

Gulson, Brian, E-mail: brian.gulson@mq.edu.au; CSIRO Earth Science and Resource Engineering North Ryde, NSW 1670; Korsch, Michael

In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments,more » air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty. - Highlights: Black-Right-Pointing-Triangle Lead carbonate concentrate. Black-Right-Pointing-Triangle Successful use of Pb isotopes in identifying sources of Pb arising from transport and shipping. Black-Right-Pointing-Triangle Use of Pb isotopes in legal proceedings and their use in cleanup of residences. Black-Right-Pointing-Triangle Use of Pb isotopes in cleanup of a residual 9000 tonnes of Pb carbonate and in ongoing monitoring.« less

Macroscopic and molecular-scale assessment of soil lead contamination impacted by seasonal dove hunting activities

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

Arai, Y.; Tappero, R.; Rick, A.R.

Environmental contamination of lead (Pb) in soils and sediments poses serious threats to human and ecological health. The objective of this study is to investigate the effect of seasonal dove sports hunting activities on Pb contamination in acid forest soils. A grid sampling method was used to investigate the spatial distribution of Pb contamination in surface soils. Soils were analyzed for total metal(loid) concentration and characterized for physicochemical properties and mineralogy. Adsorption isotherm experiments were also conducted to understand the reactivity and retention capacity of Pb(II) in soils. Finally, synchrotron-based X-ray microprobe and X-ray absorption spectroscopy were used to understandmore » the chemical speciation of Pb that controls the retention/release mechanisms of Pb in soils. There was no excessive accumulation of Pb at the site. However, the concentration of Pb in surface soils was greater than the background level (<16 mg kg{sup -1}). The contamination level of Pb was as high as 67 mg kg{sup -1} near a patch of corn field where lime was frequently applied. A microfocused X-ray microprobe analysis showed the presence of Pb pellet fragments that predominantly contain oxidized Pb(II), suggesting that oxidative dissolution was occurring in soils. Dissolved Pb(II) can be readily retained in soils up to {approx}3,600 mg kg{sup -1} via inner-sphere and outer-sphere surface complexation on carbon and aluminol functional groups of soil components, suggesting that partitioning reactions control the concentration of Pb in soil solution. The fate of Pb is likely to be controlled by (1) oxidative dissolution process of Pb(0) pellets and (2) the release of outer-sphere and/or inner-sphere Pb surface complexes in humic substances and aluminosilicate/Al oxyhydroxides. Although no remedial actions are immediately required, the long-term accumulation of Pb in soils should be carefully monitored in protecting ecosystem and water quality at the dove hunting field.« less

Biochemical changes in longear sunfish, Lepomis megalotis, associated with lead, cadmium and zinc from mine tailings

USGS Publications Warehouse

Dwyer, F.J.; Schmitt, C.J.; Finger, S.E.; Mehrle, P.M.

1988-01-01

Longear sunfish were collected from a stream contaminated with mine tailings rich in lead (Pb), cadmium (Cd) and zinc (Zn). Blood samples were analysed for δ-aminolevulinic acid dehydratase (ALA-D) activity and Pb concentration. Vertebrae were tested for bone strength and composition, and Pb, Zn, and Cd concentrations were determined in muscle tissue. ALA-D activity was negatively correlated with blood Pb concentration (r=–0.66), and enzyme activity was significantly higher and blood Pb significantly lower at the reference site than at the contaminated sites. Blood Pb was highly correlated with Pb in muscle tissue (r= 0.72), and the concentrations of Pb and Cd in muscle tissues were themselves correlated (r= 0.64). In fish from contaminated sites, two of the mechanical properties of the vertebrae measured (elastic limit and modulus of elasticity) were significantly different from values in fish from the reference site. These properties and one other (stress) were weakly correlated with muscle Cd concentration (0.42 < r < 0.46). Biochemical differences among fish from different sites were also evident; concentrations of calcium, phosphorus and collagen were lower in the vertebrae of fish from some of the contaminated sites than at the reference site, and bone phosphorus was negatively correlated with concentrations of Pb in both muscle (r=– 0.62) and blood (r=– 0.75). Collectively, these results indicate that, in addition to the well-documented effects of Pb on haem synthesis, other important biochemical pathways may be disrupted by continuous low-level exposure to elemental contaminants.

Effectiveness of arbuscular mycorrhizal fungi in phytoremediation of lead- contaminated soil by vetiver grass.

PubMed

Bahraminia, Mahboobeh; Zarei, Mehdi; Ronaghi, Abdolmajid; Ghasemi-Fasaei, Reza

2016-01-01

A greenhouse experiment was conducted to evaluate the effectiveness of arbuscular mycorrhizal (AM) fungi in phytoremediation of lead (Pb)-contaminated soil by vetiver grass. Experiment was a factorial arranged in a completely randomized design. Factors included four Pb levels (50, 200, 400, and 800 mg kg(-1)) as Pb (NO3)2, AM fungi at three levels (non mycorrhizal (NM) control, Rhizophagus intraradices, Glomus versiforme). Shoot and root dry weights (SDW and RDW) decreased as Pb levels increased. Mycorrhizal inoculation increased SDW and RDW compared to NM control. With mycorrhizal inoculation and increasing Pb levels, Pb uptake of shoot and root increased compared to those of NM control. Root colonization increased with mycorrhizal inoculation but decreased as Pb levels increased. Phosphorus concentration and uptake in shoot of plants inoculated with AM fungi was significantly higher than NM control at 200 and 800 mg Pb kg(-1). The Fe concentration, Fe and Mn uptake of shoot in plants inoculated with Rhizophagus intraradices in all levels of Pb were significantly higher than NM control. Mycorrhizal inoculation increased Pb extraction, uptake and translocation efficiencies. Lead translocation factor decreased as Pb levels increased; however inoculation with AM fungi increased Pb translocation.

Some Pb and Sr isotopic measurements on eclogites from the Roberts Victor mine, South Africa

USGS Publications Warehouse

Manton, W.I.; Tatsumoto, M.

1971-01-01

Five nodules of eclogite, one nodule of garnet peridotite and one sample of kimberlite from the Roberts Victor mine were analyzed for concentrations of U, Th, Pb, Rb and Sr and isotopic compositions of Pb and Sr. In the eclogites, U content ranges from 0.09 to 0.26 ppm, Th from 0.35 to 1.1 ppm, Pb from 0.79 to 5.5 ppm, Rb from 2.1 to 28 ppm and Sr from 133 to 346 ppm; 206Pb/204Pb ratios range from 14.8 to 18.5, 207Pb/204Pb from 14.9 to 15.7, 208Pb/204Pb from 35.2 to 38.5. The garnet peridotite contains 0.22 ppm U, 0.97 ppm Th, 1.05 ppm Pb, 6.9 ppm Rb and 108 ppm Sr and the kimberlite contains 2.5 ppm U, 30 ppm Th, 37 ppm Pb, 113 ppm Rb and 2040 ppm Sr. The lead in the eclogites has two components, a lead pyroextractable at 1100-1200?? and a non-pyroextractable residual lead. In three of the eclogites, which are to some extent altered, a proportion of the pyroextractable lead may be contaminating lead from the kimberlite, but an altered kyanite eclogite does not appear to be contaminated by this same kimberlite. The pyroextractable lead from a less altered eclogite contains a much larger proportion of 206Pb. Compositions calculated for the residual leads vary greatly. In many of the pyroextraction runs the primary eclogitic phases disappeared and the new phases plagioclase, clinopyroxene and a magnetic iron compound were formed. Why part of the lead should have been retained by these new phases is not understood. ?? 1971.

The identification of lead ammunition as a source of lead exposure in First Nations: the use of lead isotope ratios.

PubMed

Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

2008-04-15

The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of (206)Pb/(204)Pb and (206)Pb/(207)Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (p<0.05) positive correlations for (206)Pb/(204)Pb and (206)Pb/(207)Pb, and a significant negative correlation for (208)Pb/(206)Pb, as predicted if leaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden.

Lead stabilization by phosphate amendments in soil impacted by paint residue.

PubMed

Schwab, A P; Lewis, K; Banks, M K

2006-01-01

The addition of phosphate was evaluated for contaminant stabilization in soils impacted by lead paint residue. Soils sampled from 15 highway bridge sites in Indiana were screened based on residual lead concentrations from paint contamination. Two appropriate bridge sites were identified in Tippecanoe County, Indiana. Soluble phosphate was added to the soil at a mole ratio of 3:1 P:Pb. The efficacy of phosphate treatment was evaluated by a physiologically based extraction test (PBET), uptake of lead by sunflowers, and leaching of lead from soil columns. Sunflowers were established on both field sites, and the mean Pb concentration in the above-ground biomass indicated that the rate of uptake was similar to plants growing in uncontaminated soil. The second bioavailability assessment was the physiologically based extraction test, designed to evaluate heavy metal availability during ingestion. After 1 year at both sites, the addition of phosphate significantly reduced the concentrations of lead extracted by PBET, indicating that the lead in the amended soils had lower bioavailability than in the unamended soils. In the column study, the contaminated soil produced the highest mass of leached Pb, and the addition of P reduced the mass of Pb in the leachate to similar levels found in the uncontaminated soil. Overall, the addition of soluble phosphate to these soils appears to be an effective approach for immobilizing Pb and reducing the associated bio-accessibility.

Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring.

PubMed

Gulson, Brian; Korsch, Michael; Winchester, Wayne; Devenish, Matthew; Hobbs, Thad; Main, Cleve; Smith, Gerard; Rosman, Kevin; Howearth, Lynette; Burn-Nunes, Laurie; Seow, Jimmy; Oxford, Cameron; Yun, Gracie; Gillam, Lindsay; Crisp, Michelle

2012-01-01

In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments, air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Geochemistry Of Lead In Contaminated Soils: Effects Of Soil Physico-Chemical Properties

NASA Astrophysics Data System (ADS)

Saminathan, S.; Sarkar, D.; Datta, R.; Andra, S. P.

2006-05-01

Lead (Pb) is an environmental contaminant with proven human health effects. When assessing human health risks associated with Pb, one of the most common exposure pathways typically evaluated is soil ingestion by children. However, bioaccessibility of Pb primarily depends on the solubility and hence, the geochemical form of Pb, which in turn is a function of site specific soil chemistry. Certain fractions of ingested soil-Pb may not dissociate during digestion in the gastro-intestinal tract, and hence, may not be available for transport across the intestinal membrane. Therefore, this study is being currently performed to assess the geochemical forms and bioaccessibility of Pb in soils with varying physico-chemical properties. In order to elucidate the level of Pb that can be ingested and assimilated by humans, an in-vitro model that simulates the physiological conditions of the human digestive system has been developed and is being used in this study. Four different types of soils from the Immokalee (an acid sandy soil with minimal Pb retention potential), Millhopper (a sandy loam with high Fe/Al content), Pahokee (a muck soil with more than 80% soil organic matter), and Tobosa series (an alkaline soil with high clay content) were artificially contaminated with Pb as lead nitrate at the rate equivalent to 0, 400, 800, and 1200 mg/kg dry soil. Analysis of soils by a sequential extraction method at time zero (immediately after spiking) showed that Immokalee and Millhopper soils had the highest amount of Pb in exchangeable form, whereas Pahokee and Tobosa soils had higher percentages of carbonate-bound and Fe/Al-bound Pb. The results of in-vitro experiment at time zero showed that majority of Pb was dissolved in the acidic stomach environment in Immokalee, Millhopper, and Tobosa, whereas it was in the intestinal phase in Pahokee soils. Because the soil system is not in equilibrium at time zero, the effect of soil properties on Pb geochemistry is not clear as yet. The subsequent analysis of soils (after 6 and 8 months months) is expected to better demonstrate the influence of soil properties on human bioaccessibility of Pb in contaminated soils. Furthermore, the geochemical forms of Pb will be correlated with bioaccessible Pb to identify those soil-Pb species with higher solubility in the human gastrointestinal system. Key words: Lead, Geochemical species, Bioaccessibility, In-vitro model, Health risk

Soil microbial respiration and PICT responses to an industrial and historic lead pollution: a field study.

PubMed

Bérard, Annette; Capowiez, Line; Mombo, Stéphane; Schreck, Eva; Dumat, Camille; Deola, Frédéric; Capowiez, Yvan

2016-03-01

We performed a field investigation to study the long-term impacts of Pb soil contamination on soil microbial communities and their catabolic structure in the context of an industrial site consisting of a plot of land surrounding a secondary lead smelter. Microbial biomass, catabolic profiles, and ecotoxicological responses (PICT) were monitored on soils sampled at selected locations along 110-m transects established on the site. We confirmed the high toxicity of Pb on respirations and microbial and fungal biomasses by measuring positive correlations with distance from the wall factory and negative correlation with total Pb concentrations. Pb contamination also induced changes in microbial and fungal catabolic structure (from carbohydrates to amino acids through carboxylic malic acid). Moreover, PICT measurement allowed to establish causal linkages between lead and its effect on biological communities taking into account the contamination history of the ecosystem at community level. The positive correlation between qCO2 (based on respiration and substrate use) and PICT suggested that the Pb stress-induced acquisition of tolerance came at a greater energy cost for microbial communities in order to cope with the toxicity of the metal. In this industrial context of long-term polymetallic contamination dominated by Pb in a field experiment, we confirmed impacts of this metal on soil functioning through microbial communities, as previously observed for earthworm communities.

Three-dimensional data interpolation for environmental purpose: lead in contaminated soils in southern Brazil.

PubMed

Piedade, Tales Campos; Melo, Vander Freitas; Souza, Luiz Cláudio Paula; Dieckow, Jeferson

2014-09-01

Monitoring of heavy metal contamination plume in soils can be helpful in establishing strategies to minimize its hazardous impacts to the environment. The objective of this study was to apply a new approach of visualization, based on tridimensional (3D) images, of pseudo-total (extracted with concentrated acids) and exchangeable (extracted with 0.5 mol L(-1) Ca(NO3)2) lead (Pb) concentrations in soils of a mining and metallurgy area to determine the spatial distribution of this pollutant and to estimate the most contaminated soil volumes. Tridimensional images were obtained after interpolation of Pb concentrations of 171 soil samples (57 points × 3 depths) with regularized spline with tension in a 3D function version. The tridimensional visualization showed great potential of use in environmental studies and allowed to determine the spatial 3D distribution of Pb contamination plume in the area and to establish relationships with soil characteristics, landscape, and pollution sources. The most contaminated soil volumes (10,001 to 52,000 mg Pb kg(-1)) occurred near the metallurgy factory. The main contamination sources were attributed to atmospheric emissions of particulate Pb through chimneys. The large soil volume estimated to be removed to industrial landfills or co-processing evidenced the difficulties related to this practice as a remediation strategy.

Effects of arsenic and cadmium on bioaccessibility of lead in spiked soils assessed by Unified BARGE Method.

PubMed

Xia, Qing; Peng, Cheng; Lamb, Dane; Kader, Mohammed; Mallavarapu, Megharaj; Naidu, Ravi; Ng, Jack C

2016-07-01

The bioaccessibility of lead (Pb) in contaminated soils has been extensively studied, including the influence of soil properties on Pb bioaccessibility. However, little is known about the effects of other metals/metalloid, such as arsenic (As), cadmium (Cd) on the bioaccessibility of Pb, i.e. whether As or Cd could increase or decrease the solubility of Pb in human gastrointestinal tract when Pb-contaminated soil and As-contaminated (or Cd-contaminated) soil are ingested simultaneously. Furthermore, it is far from clear that if soil property could make a difference to these effects. In this study, seven types of soils were collected in Australia and spiked with As, Cd or Pb. Gastric bioaccessibility of Pb ranged from 44 ± 0.9% to 100 ± 6.7% whilst intestinal bioaccessibility dropped to 1 ± 0.2% to 36 ± 1.7%. Statistical analysis shows total Pb in soil was the most significant controller for bioaccessible Pb. Effects of As and Cd on the bioaccessibility of Pb in simulated human digestive system were studied by mixing As-spiked soil (or Cd-spiked soil) with Pb-spiked soil of the same type during bioaccessibility test. Results reveal that neither As nor Cd had impact on Pb bioaccessibility, which indicates when As, Cd and Pb aged in soils separately, they may behave independently in the bioaccessibility measuring system. This finding can be part of evidence to assume additive effect when it comes to estimate the bioaccessibility of mixtures of independently-aged As and Pb (or Cd and Pb) in soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Metal distribution and mobility in lateritic soils affected by Cu-Co smelting in the Copperbelt district, Zambia

NASA Astrophysics Data System (ADS)

Ettler, Vojtech; Mihaljevic, Martin; Majer, Vladimir; Kribek, Bohdan; Sebek, Ondrej

2010-05-01

The copper smelting activities in the Copperbelt mining district (Zambia) left a huge pollution related to the disposal sites of smelting waste (slags) and to the continuous deposition of the smelter stack particulates in the soil systems. We sampled 196 surface and subsurface soils in the vicinity of the Nkana copper smelter at Kitwe and a 110 cm deep lateritic soil profile in order to assess the regional distribution of metallic contaminants and their vertical mobility. The content of contaminants in soil samples were measured by ICP techniques and the lead isotopic compositions (206Pb/207Pb and 208Pb/206Pb ratios) were determined by ICP-MS. The spatial distribution of the major contaminants (Cu, Co, Pb, Zn) indicated the highest contamination NW of the smelter stack corresponding to the direction of prevailing winds in the area. The highest metal concentrations in soils were: 27410 ppm Cu, 606 ppm Co, 480 ppm Pb, 450 ppm Zn. Lead isotopes helped to discriminate the extent of metallic pollution related to the smelter emissions having similar 206Pb/207Pb ratio of 1.17-1.20 in contrast to the regional background value of 1.32. The investigation of the lateritic soil profile sampled in the near vicinity of the Nkana smelter indicated that contamination is mostly located in the uppermost soil horizons enriched in organic matter (< 10 cm). The sequential extraction procedure indicated that up to 33% of Cu and <10% of Co, Pb and Zn was mobile in the profile, being bound in the exchangeable fraction. However, in the deeper parts of the soil profile, metals were mostly bound in reducible fraction, presumably to hydrous ferric oxides. The combination of sequential extraction and lead isotopic determination indicated that the "mobile" fractions of Pb in the soil profile corresponded to the signatures of smelter particulate emissions (206Pb/207Pb = 1.17-1.20), which means that the anthropogenic emissions are the important source of mobile (and potentially bioavailable) metals.

Reconstruction of historical lead contamination and sources in Lake Hailing, Eastern China: a Pb isotope study.

PubMed

Zhang, Rui; Guan, Minglei; Shu, Yujie; Shen, Liya; Chen, Xixi; Zhang, Fan; Li, Tiegang; Jiang, Tingchen

2016-05-01

The history records of lead and its stable isotopic ratios were determined in a sediment core to receive anthropogenic impacts on the Lake Hailing in eastern China. The sediment core was dated based on (210)Pb, (137)Cs, and (239+240)Pu. The historical changes of Pb/Al and Pb isotope ratios showed increasing trend upward throughout the core, suggesting changes in energy usage and correlating closely with the experience of a rapid economic and industrial development of the catchment, Linyi City, in eastern China. Based on the mixing end member model of Pb isotope ratios, coal combustion emission dominated anthropogenic Pb sources in the half part of the century contributing 13 to 43 % of total Pb in sediment. Moreover, contributions of chemical and organic fertilizer were 1-13 and 5-14 %, respectively. In contrast, the contribution of leaded gasoline was low than 8 %. The results indicated that historical records of Pb contamination predominantly sourced from coal combustion and chemical and organic fertilizer in the catchment. In addition, an increase of coal combustion source and fertilizers was found throughout the sediment core, whereas the contribution of leaded gasoline had declined after 2000s, which is attributed to the phaseout of leaded gasoline in China.

Relationship Between Total and Bioaccessible Lead on Children’s Blood Lead Levels in Urban Residential Philadelphia Soils

EPA Science Inventory

Relationships between total soil or bioaccessible lead (Pb), measured using an in vitro bioaccessibility assay, and children’s blood lead levels (BLL) were investigated in an urban neighborhood in Philadelphia, Pennsylvania, USA, with a history of soil Pb contamination....

Effects of soil type and genotype on lead concentration in rootstalk vegetables and the selection of cultivars for food safety.

PubMed

Ding, Changfeng; Zhang, Taolin; Wang, Xingxiang; Zhou, Fen; Yang, Yiru; Yin, Yunlong

2013-06-15

Lead (Pb) contamination of soil poses severe health risks to humans through vegetable consumption. The variations of Pb concentration in different parts of rootstalk vegetables (radish, carrot and potato) were investigated by using twelve cultivars grown in acidic Ferralsols and neutral Cambisols under two Pb treatments (125 mg kg(-1) and 250 mg kg(-1) for Ferralsols; 150 mg kg(-1) and 300 mg kg(-1) for Cambisols) in a pot experiment. The Pb concentration in edible parts was higher in Ferralsols under two Pb treatments, with range from 0.28 to 4.14, 0.42-10.66 mg kg(-1) (fresh weight) respectively, and all of them exceeded the food safety standard (0.1 mg kg(-1)) recommended by the Codex Alimentarius Commission of FAO and WHO. The Pb concentration in edible parts was significantly affected by genotype, soil type and the interaction between these two factors. The variation of Pb concentration in different cultivars was partially governed by Pb absorption and the transfer of Pb from aerial to edible part. The results revealed that caution should be paid to the cultivation of rootstalk vegetables in Pb-contaminated Ferralsols without any agronomic management to reduce Pb availability and plant uptake. For Cambisols with slight to moderate Pb contamination, growing potato cultivar Shandong No.1 and Chongqing No.1 was effective in reducing the risk of Pb entering human food chain. The results suggest the possibility of developing cultivar- and soil-specific planting and monitoring guidelines for the cultivation of rootstalk vegetables on slight to moderate Pb-contaminated soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

USGS Publications Warehouse

Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

1999-01-01

Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that geochemical cycling of lead between sediments and water accounts for persistently elevated lead concentrations in the water column despite 10-fold reduction of external source inputs to San Francisco Bay [Flegal, A.R., Rivera-Duarte, I., Ritson, P.I., Scelfo, G., Smith, G.J., Gordon, M., Sanudo-Wilhelmy, S.A., 1996. Metal contamination in San Francisco Waters: historic perturbations, contemporary concentrations, and future considerations in San Francisco Bay. In: Hollobaugh, J.T. (Ed.), The Ecosystem. AAAS, pp. 173-188].

Bioaccessibility tests accurately estimate bioavailability of lead to quail.

PubMed

Beyer, W Nelson; Basta, Nicholas T; Chaney, Rufus L; Henry, Paula F P; Mosby, David E; Rattner, Barnett A; Scheckel, Kirk G; Sprague, Daniel T; Weber, John S

2016-09-01

Hazards of soil-borne lead (Pb) to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, the authors measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from 5 Pb-contaminated Superfund sites had relative bioavailabilities from 33% to 63%, with a mean of approximately 50%. Treatment of 2 of the soils with phosphorus (P) significantly reduced the bioavailability of Pb. Bioaccessibility of Pb in the test soils was then measured in 6 in vitro tests and regressed on bioavailability: the relative bioavailability leaching procedure at pH 1.5, the same test conducted at pH 2.5, the Ohio State University in vitro gastrointestinal method, the urban soil bioaccessible lead test, the modified physiologically based extraction test, and the waterfowl physiologically based extraction test. All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the relative bioavailability leaching procedure at pH 2.5 and Ohio State University in vitro gastrointestinal tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter (24%), or present as Pb sulfate (18%). Additional Pb was associated with P (chloropyromorphite, hydroxypyromorphite, and tertiary Pb phosphate) and with Pb carbonates, leadhillite (a lead sulfate carbonate hydroxide), and Pb sulfide. The formation of chloropyromorphite reduced the bioavailability of Pb, and the amendment of Pb-contaminated soils with P may be a thermodynamically favored means to sequester Pb. Environ Toxicol Chem 2016;35:2311-2319. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

Biosurfactant technology for remediation of cadmium and lead contaminated soils.

PubMed

Juwarkar, Asha A; Nair, Anupa; Dubey, Kirti V; Singh, S K; Devotta, Sukumar

2007-08-01

This research focuses on column experiments conducted to evaluate the potential of environmentally compatible rhamnolipid biosurfactant produced by Pseudomonas aeruginosa strain BS2 to remove heavy metals (Cd and Pb) from artificially contaminated soil. Results have shown that di-rhamnolipid removes not only the leachable or available fraction of Cd and Pb but also the bound metals as compared to tap water which removed the mobile fraction only. Washing of contaminated soil with tap water revealed that approximately 2.7% of Cd and 9.8% of Pb in contaminated soil was in freely available or weakly bound forms whereas washing with rhamnolipid removed 92% of Cd and 88% of Pb after 36 h of leaching. This indicated that di-rhamnolipid selectively favours mobilization of metals in the order of Cd>Pb. Biosurfactant specificity observed towards specific metal will help in preferential elution of specific contaminant using di-rhamnolipid. It was further observed that pH of the leachates collected from heavy metal contaminated soil column treated with di-rhamnolipid solution was low (6.60-6.78) as compared to that of leachates from heavy metal contaminated soil column treated with tap water (pH 6.90-7.25), which showed high dissolution of metal species from the contaminated soil and effective leaching of metals with treatment with biosurfactant. The microbial population of the contaminated soil was increased after removal of metals by biosurfactant indicating the decrease of toxicity of metals to soil microflora. This study shows that biosurfactant technology can be an effective and nondestructive method for bioremediation of cadmium and lead contaminated soil.

ADSORPTION OF LEAD FROM A CONTAMINATED SOIL TREATED WITH PHOSPHORUS AND MANGANESE OXIDES BY APRAGUE-DAWLEY RATS

EPA Science Inventory

In addition to the formation of insoluble lead (Pb) compounds as a mean of reducing Pb bioavalability, adsorption is another potentially important process controlling the bioavailability of Pb in soils. Less attention has been given to manganese (Mn) oxides, even though they are ...

A study on possible use of Urtica dioica (common nettle) plant as polonium (210)Po and lead (210)Pb contamination biomonitor in the area of phosphogypsum stockpile.

PubMed

Olszewski, Grzegorz; Boryło, Alicja; Skwarzec, Bogdan

2016-04-01

The aim of this study was to test a possible use of Urtica dioica (common nettle) plant as a biomonitor of polonium (210)Po and lead (210)Pb contamination near phosphogypsum stacks by determining concentrations of these radionuclides in samples collected from the area of phosphogypsum stockpile in Wiślinka (northern Poland). The (210)Po and (210)Pb contents in roots depended on their concentrations in soils. Bioconcentration factor values from soil to root of the plant did not depend on (210)Po and (210)Pb contents in soils that leads to the conclusion that different polonium and lead species have different affinities to U. dioica plants. The main sources of both analyzed radionuclides in green parts of plants are wet and dry air deposition and transportation from soil. The values of (210)Po/(210)Pb activity ratio indicate natural origin of these radioisotopes in analyzed plants. (210)Po and (210)Pb concentration in U. dioica roots is negatively weakly correlated with distance from phosphogypsum stockpile.

Evaluating specificity of sequential extraction for chemical forms of lead in artificially-contaminated and field-contaminated soils.

PubMed

Tai, Yiping; McBride, Murray B; Li, Zhian

2013-03-30

In the present study, we evaluated a commonly employed modified Bureau Communautaire de Référence (BCR test) 3-step sequential extraction procedure for its ability to distinguish forms of solid-phase Pb in soils with different sources and histories of contamination. When the modified BCR test was applied to mineral soils spiked with three forms of Pb (pyromorphite, hydrocerussite and nitrate salt), the added Pb was highly susceptible to dissolution in the operationally-defined "reducible" or "oxide" fraction regardless of form. When three different materials (mineral soil, organic soil and goethite) were spiked with soluble Pb nitrate, the BCR sequential extraction profiles revealed that soil organic matter was capable of retaining Pb in more stable and acid-resistant forms than silicate clay minerals or goethite. However, the BCR sequential extraction for field-collected soils with known and different sources of Pb contamination was not sufficiently discriminatory in the dissolution of soil Pb phases to allow soil Pb forms to be "fingerprinted" by this method. It is concluded that standard sequential extraction procedures are probably not very useful in predicting lability and bioavailability of Pb in contaminated soils. Copyright © 2013 Elsevier B.V. All rights reserved.

Status of metal levels and their potential sources of contamination in Southeast Asian rivers.

PubMed

Chanpiwat, Penradee; Sthiannopkao, Suthipong

2014-01-01

To assess the concentration and status of metal contaminants in four major Southeast Asian river systems, water were collected from the Tonle Sap-Bassac Rivers (Cambodia), Citarum River (Indonesia), lower Chao Phraya River (Thailand), and Saigon River (Vietnam) in both dry and wet seasons. The target elements were Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Ba, Tl, and Pb and the concentrations exceeded the background metal concentrations by 1- to 88-fold. This distinctly indicates enrichment by human urban area activities. The results of a normalization technique used to distinguish natural from enriched metal concentrations confirmed contamination by Al, Cd, Co, Mn, Ni, Pb, and Zn. Cluster analysis revealed the probable source of metals contamination in most sampling sites on all rivers studied to be anthropogenic, including industrial, commercial, and residential activities. Stable lead isotopes analyses applied to track the sources and pathways of anthropogenic lead furthermore confirmed that anthropogenic sources of metal contaminated these rivers. Discharges of wastewater from both industrial and household activities were major contributors of Pb into the rivers. Non-point sources, especially road runoff and street dust, also contributed contamination from Pb and other metals.

FORMATION OF CHLOROPYROMORPHITE IN A LEAD-CONTAMINATED SOIL AMENDED WITH HYDROXYAPATITE

EPA Science Inventory

To evaluate conversion of soil Pb to pyromorphite, a Pb contaminated soil collected adjacent to a historical smelter was reacted with hydroxyapatite in a traditional incubation experiment and in a dialysis system in which the soil and hydroxyapatite solids were separated by a dia...

Effects of ferrous sulfate amendment and water management on rice growth and metal(loid) accumulation in arsenic and lead co-contaminated soil.

PubMed

Zou, Lina; Zhang, Shu; Duan, Dechao; Liang, Xinqiang; Shi, Jiyan; Xu, Jianming; Tang, Xianjin

2018-03-01

Arsenic (As) and lead (Pb) commonly co-exist with high concentrations in paddy soil mainly due to human activities in south of China. This study investigates the effect of ferrous sulfate (FeSO 4 ) amendment and water management on rice growth and arsenic (As) and lead (Pb) accumulation in rice plants. A paddy soil co-contaminated with As and Pb was chosen for the pot experiment with three FeSO 4 levels (0, 0.25, and 1%, on a dry weight basis) and two water managements (flooded, non-flooded). The concentrations of As and Pb in iron plaques and rice plants were determined. Application of FeSO 4 and non-flooded conditions significantly accelerated the growth of rice plants. With the addition of FeSO 4 , iron plaques were significantly promoted and most of the As and Pb were sequestered in the iron plaques. The addition of 0.25% FeSO 4 and non-flooded conditions did not significantly change the accumulation of As and Pb in rice grains. The practice also significantly decreased the translocation factor (TF) of As and Pb from roots to above-ground parts which might have been aided by the reduction of As and Pb availability in soil, the preventing effect of rice roots, and the formation of more reduced glutathione (GSH). Flooded conditions decreased the Pb concentration in rice plants, but increased As accumulation. Moreover, rice grew thin and weak and even died under flooded conditions. Overall, an appropriate FeSO 4 dose and non-flooded conditions might be feasible for rice cultivation, especially addressing the As issue in the co-contaminated soil. However, further detailed studies to decrease the accumulation of Pb in edible parts and the field application in As and Pb co-contaminated soil are recommended.

Bioaccessibility tests accurately estimate bioavailability of lead to quail

USDA-ARS?s Scientific Manuscript database

Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb, we incorporated Pb-contaminated soils or Pb acetate into diets for Japanese quail (Coturnix japonica), fed the quail for 15 days, and ...

Estimating Lead (Pb) Bioavailability In A Mouse Model

EPA Science Inventory

Children are exposed to Pb through ingestion of Pb-contaminated soil. Soil Pb bioavailability is estimated using animal models or with chemically defined in vitro assays that measure bioaccessibility. However, bioavailability estimates in a large animal model (e.g., swine) can be...

Lead and cadmium contamination and exposure risk assessment via consumption of vegetables grown in agricultural soils of five-selected regions of Pakistan

PubMed Central

Rehman, Zahir Ur; Khan, Sardar; Brusseau, Mark L; Shah, Mohammad Tahir

2017-01-01

Rapid urbanization and industrialization result in serious contamination of soil with toxic metals such as lead (Pb) and cadmium (Cd), which can lead to deleterious health impacts in the exposed population. This study aimed to investigate Pb and Cd contamination in agricultural soils and vegetables in five different agricultural sites in Pakistan. The metal transfer from soil-to-plant, average daily intake of metals, and health risk index (HRI) were also characterized. The Pb concentrations for all soils were below the maximum allowable limits (MAL 350 mg kg−1) set by the State Environmental Protection Administration of China (SEPA), for soils in China. Conversely, Cd concentrations in the soils exceeded the MAL set by SEPA (0.6 mg kg−) and the European Union (1.5 mg kg−1) by 62-74% and 4-34%, respectively. The mean Pb concentration in edible parts of vegetables ranged from 1.8-11 mgkg−1. The Pb concentrations for leafy vegetables were higher than the fruiting and pulpy vegetables. The Pb concentrations exceeded the MAL (0.3 mg kg−1) for leafy vegetables and the MAL for fruity and rooty/tuber vegetables (0.1 mg kg−1) set by FAO/WHO-CODEX.. Likewise, all vegetables except Pisum sativum (0.12 mg kg−1) contained Cd concentrations that exceeded the MAL set by SEPA. The HRI values for Pb and Cd were <1 for both adults and children for most of the vegetable species except Luffa acutangula, Solanum lycopersicum, Benincasa hispada, Momordi charantia, Aesculantus malvaceae, Cucumis sativus, Praecitrullus fistulosus, Brassica oleracea, and Colocasia esculanta for children. Based on these results, consumption of these Pb and Cd contaminated vegetables poses a potential health risk to the local consumers. PMID:27939659

Phytoextraction of lead-contaminated soil using vetivergrass (Vetiveria zizanioides L.), cogongrass (Imperata cylindrica L.) and carabaograss (Paspalum conjugatum L.).

PubMed

Paz-Alberto, Annie Melinda; Sigua, Gilbert C; Baui, Bellrose G; Prudente, Jacqueline A

2007-11-01

The global problem concerning contamination of the environment as a consequence of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contributes to a variety of health effects such as decline in mental, cognitive and physical health of the individual. An alternative way of reducing Pb concentration from the soil is through phytoremediation. Phytoremediation is an alternative method that uses plants to clean up a contaminated area. The objectives of this study were: (1) to determine the survival rate and vegetative characteristics of three grass species such as vetivergrass, cogongrass and carabaograss grown in soils with different Pb levels; and (2) to determine and compare the ability of the three grass species as potential phytoremediators in terms of Pb accumulation by plants. The three test plants: vetivergrass (Vetiveria zizanioides L.); cogongrass (Imperata cylindrica L.); and carabaograss (Paspalum conjugatum L.) were grown in individual plastic bags containing soils with 75 mg kg(-1) (37.5 kg ha(-1)) and 150 mg kg(-1) (75 kg ha(-1)) of Pb, respectively. The Pb contents of the test plants and the soil were analyzed before and after experimental treatments using an atomic absorption spectrophotometer. This study was laid out following a 3 x 2 factorial experiment in a completely randomized design. On the vegetative characteristics of the test plants, vetivergrass registered the highest whole plant dry matter weight (33.85-39.39 Mg ha(-1)). Carabaograss had the lowest herbage mass production of 4.12 Mg ha(-1) and 5.72 Mg ha(-1) from soils added with 75 and 150 mg Pb kg(-1), respectively. Vetivergrass also had the highest percent plant survival which meant it best tolerated the Pb contamination in soils. Vetivergrass registered the highest rate of Pb absorption (10.16 +/- 2.81 mg kg(-1)). This was followed by cogongrass (2.34 +/- 0.52 mg kg(-1)) and carabaograss with a mean Pb level of 0.49 +/- 0.56 mg kg(-1). Levels of Pb among the three grasses (shoots + roots) did not vary significantly with the amount of Pb added (75 and 150 mg kg(-1)) to the soil. Vetivergrass yielded the highest biomass; it also has the greatest amount of Pb absorbed (roots + shoots). This can be attributed to the highly extensive root system of vetivergrass with the presence of an enormous amount of root hairs. Extensive root system denotes more contact to nutrients in soils, therefore more likelihood of nutrient absorption and Pb uptake. The efficiency of plants as phytoremediators could be correlated with the plants' total biomass. This implies that the higher the biomass, the greater the Pb uptake. Plants characteristically exhibit remarkable capacity to absorb what they need and exclude what they do not need. Some plants utilize exclusion mechanisms, where there is a reduced uptake by the roots or a restricted transport of the metals from root to shoots. Combination of high metal accumulation and high biomass production results in the most metal removal from the soil. The present study indicated that vetivergrass possessed many beneficial characteristics to uptake Pb from contaminated soil. It was the most tolerant and could grow in soil contaminated with high Pb concentration. Cogongrass and carabaograss are also potential phytoremediators since they can absorb small amount of Pb in soils, although cogongrass is more tolerant to Pb-contaminated soil compared with carabaograss. The important implication of our findings is that vetivergrass can be used for phytoextraction on sites contaminated with high levels of heavy metals, particularly Pb. High levels of Pb in localized areas are still a concern especially in urban areas with high levels of traffic, near Pb smelters, battery plants, or industrial facilities that burn fuel ending up in water and soils. The grasses used in the study, and particularly vetivergrass, can be used to phytoremediate urban soil with various contaminations by planting these grasses in lawns and public parks.

Contamination and human health risk of lead in soils around lead/zinc smelting areas in China.

PubMed

Lei, Kai; Giubilato, Elisa; Critto, Andrea; Pan, Huiyun; Lin, Chunye

2016-07-01

Pb/Zn smelting, an important economic activity in China, has led to heavy environmental pollution. This research reviewed studies on soil Pb contamination at Pb/Zn smelting sites in China published during the period of 2000 to 2015 to clarify the total levels, spatial changes, and health risks for Pb contamination in soils at local and national scales. The results show that Pb contents in surface soils at 58 Pb/Zn smelting sites in China ranged from 7 to 312,452 mg kg(-1) with an arithmetic average, geometric average, and median of 1982, 404, and 428 mg kg(-1), respectively (n = 1011). Surface soil Pb content at these smelting sites decreased from an average of 2466 to 659 mg kg(-1), then to 463 mg kg(-1) as the distance from the smelters increased from <1000 to 1000∼2000 m, and then to >2000 m. With respect to variation with depth, the average soil Pb content at these sites gradually decreased from 986 mg kg(-1) at 0- to 20-cm depth to 144 mg kg(-1) at 80- to 100-cm depth. Approximately 78 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites were classified as having high Pb pollution levels. Approximately 34.2 and 7.7 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites might pose adverse health effects and high chronic risks to children, respectively. The Pb/Zn smelting sites in the southwest and southeast provinces of China, as well as Liaoning province, were most contaminated and thus should receive priority for remediation.

Stabilization of lead (Pb) and zinc (Zn) in contaminated rice paddy soil using starfish: A preliminary study.

PubMed

Moon, Deok Hyun; Hwang, Inseong; Koutsospyros, Agamemnon; Cheong, Kyung Hoon; Ok, Yong Sik; Ji, Won Hyun; Park, Jeong-Hun

2018-05-01

Lead (Pb) and zinc (Zn) contaminated rice paddy soil was stabilized using natural (NSF) and calcined starfish (CSF). Contaminated soil was treated with NSF in the range of 0-10 wt% and CSF in the range of 0-5 wt% and cured for 28 days. Toxicity characteristic leaching procedure (TCLP) test was used to evaluate effectiveness of starfish treatment. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) analyses were conducted to investigate the mechanism responsible for effective immobilization of Pb and Zn. Experimental results suggest that NSF and CSF treatments effectively immobilize Pb and Zn in treated rice paddy soil. TCLP levels for Pb and Zn were reduced with increasing NSF and CSF dosage. Comparison of the two treatment methods reveals that CSF treatment is more effective than NSF treatment. Leachability of the two metals is reduced approximately 58% for Pb and 51% for Zn, upon 10 wt% NSF treatment. More pronounced leachability reductions, 93% for Pb and 76% for Zn, are achieved upon treatment with 5 wt% CSF. Sequential extraction results reveal that NSF and CSF treatments of contaminated soil generated decrease in exchangeable/weak acid Pb and Zn soluble fractions, and increase of residual Pb and Zn fractions. Results for the SEM-EDX sample treated with 5 wt% CSF indicate that effective Pb and Zn immobilization is most probably associated with calcium silicate hydrates (CSHs) and calcium aluminum hydrates (CAHs). Copyright © 2018 Elsevier Ltd. All rights reserved.

Potential negative consequences of adding phosphorus-based fertilizers to immobilize lead in soil

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

Kilgour, Douglas W.; Moseley, Rebecca A.; Savage, Kaye S

2008-09-01

A study of the potential negative consequences of adding phosphate (P)-based fertilizers as amendments to immobilize lead (Pb) in contaminated soils was conducted. Lead-contaminated firing range soils also contained elevated concentrations of antimony (Sb), a common Pb hardening agent, and some arsenic (As) of unknown (possibly background) origin. After amending the soils with triple superphosphate, a relatively soluble P source, column leaching experiments revealed elevated concentrations of Sb, As, and Pb in the leachate, reflecting an initial spike in soluble Pb and a particularly dramatic increase in Sb and As mobility. Minimal As, Sb, and Pb leaching was observed duringmore » column tests performed on non-amended control soils. In vitro extractions tests were performed to assess changes in Pb, As, and Sb bioaccessibility on P amendment. Lead bioaccessibility was systematically lowered with increasing P dosage, but there was much less of an effect on As and Sb bioaccessibility than on mobility. Our results indicate that although P amendments may aid in lowering the bioaccessibility of soil-bound Pb, it may also produce an initial increase in Pb mobility and a significant release of Sb and As from the soil, dramatically increasing their mobility and to a lesser extent their bioavailability.« less

Micro-X-Ray Fluorescence, Micro-X-Ray Absorption Spectroscopy, and Micro-X-Ray Diffraction Investigation of Lead Speciation after the Addition of Different Phosphorus Amendments to a Smelter-Contaminated Soil

EPA Science Inventory

The stabilization of Pb on additions of P to contaminated soils and mine spoil materials has been well documented. It is clear from the literature that different P sources result in different efficacies of Pb stabilization in the same contaminated material. We hypothesized that...

Remediation of lead-contaminated sediment by biochar-supported nano-chlorapatite: Accompanied with the change of available phosphorus and organic matters.

PubMed

Huang, Danlian; Deng, Rui; Wan, Jia; Zeng, Guangming; Xue, Wenjing; Wen, Xiaofeng; Zhou, Chengyun; Hu, Liang; Liu, Xigui; Xu, Piao; Guo, Xueying; Ren, Xiaoya

2018-04-15

Some rivers in China have been seriously contaminated due to the discharge of lead (Pb) smelting wastewater. In this study, biochar-supported nano-chlorapatite (BC-nClAP) was synthesized to immobilize Pb in contaminated sediment. The remediation effect of BC-nClAP on Pb-contaminated sediment was evaluated through batch experiments and the materials were characterized by x-ray diffraction, scanning electron microscope, Brunner-Emmet-Teller and electronic differential system. It was found that BC-nClAP can transform Pb effectively from labile fraction into stable fraction with a maximum transformation efficiency increasing to 94.1% after 30 days of treatment, and the stabilization efficiency of toxicity characteristic leaching procedure reached 100% only after 16 days of treatment. The content of available phosphorus (AP) in the sediments treated by BC-nClAP was much less than that treated by nClAP, which indicated a lower risk of eutrophication and suggested the dissolution-precipitation mechanism involved in Pb immobilization. BC-nClAP presented the best immobilization efficiency of Pb and the content of organic matters in BC-nClAP treated samples increased the most, thus the OM might play an important role during the Pb immobilization. Copyright © 2018 Elsevier B.V. All rights reserved.

Soil processes and tree growth at shooting ranges in a boreal forest reflect contamination history and lead-induced changes in soil food webs.

PubMed

Selonen, Salla; Setälä, Heikki

2015-06-15

The effects of shooting-derived lead (Pb) on the structure and functioning of a forest ecosystem, and the recovery of the ecosystem after range abandonment were studied at an active shotgun shooting range, an abandoned shooting range where shooting ceased 20 years earlier and an uncontaminated control site. Despite numerous lead-induced changes in the soil food web, soil processes were only weakly related to soil food web composition. However, decomposition of Scots pine (Pinus sylvestris) needle litter was retarded at the active shooting range, and microbial activity, microbial biomass and the rate of decomposition of Pb-contaminated grass litter decreased with increasing soil Pb concentrations. Tree (P. sylvestris) radial growth was suppressed at the active shooting range right after shooting activities started. In contrast, the growth of pines improved at the abandoned shooting range after the cessation of shooting, despite reduced nitrogen and phosphorus contents of the needles. Higher litter degradation rates and lower Pb concentrations in the topmost soil layer at the abandoned shooting range suggest gradual recovery after range abandonment. Our findings suggest that functions in lead-contaminated coniferous forest ecosystems depend on the successional stage of the forest as well as the time since the contamination source has been eliminated, which affects, e.g., the vertical distribution of the contaminant in the soil. However, despite multiple lead-induced changes throughout the ecosystem, the effects were rather weak, indicating high resistance of coniferous forest ecosystems to this type of stress. Copyright © 2015 Elsevier B.V. All rights reserved.

Legacy sediment, lead, and zinc storage in channel and floodplain deposits of the Big River, Old Lead Belt Mining District, Missouri, USA

NASA Astrophysics Data System (ADS)

Pavlowsky, Robert T.; Lecce, Scott A.; Owen, Marc R.; Martin, Derek J.

2017-12-01

The Old Lead Belt of southeastern Missouri was one of the leading producers of Pb ore for more than a century (1869-1972). Large quantities of contaminated mine waste have been, and continue to be, supplied to local streams. This study assessed the magnitude and spatial distribution of mining-contaminated legacy sediment stored in channel and floodplain deposits of the Big River in the Ozark Highlands of southeastern Missouri. Although metal concentrations decline downstream from the mine sources, the channel and floodplain sediments are contaminated above background levels with Pb and Zn along its entire 171-km length below the mine sources. Mean concentrations in floodplain cores > 2000 mg kg- 1 for Pb and > 1000 mg kg- 1 for Zn extend 40-50 km downstream from the mining area in association with the supply of fine tailings particles that were easily dispersed downstream in the suspended load. Mean concentrations in channel bed and bar sediments ranging from 1400 to 1700 mg kg- 1 for Pb extend 30 km below the mines, while Zn concentrations of 1000-3000 mg kg- 1 extend 20 km downstream. Coarse dolomite fragments in the 2-16 mm channel sediment fraction provide significant storage of Pb and Zn, representing 13-20% of the bulk sediment storage mass in the channel and can contain concentrations of > 4000 mg kg- 1 for Pb and > 1000 mg kg- 1 for Zn. These coarse tailings have been transported a maximum distance of only about 30 km from the source over a period of 120 years for an average of about 250 m/y. About 37% of the Pb and 9% of the Zn that was originally released to the watershed in tailings wastes is still stored in the Big River. A total of 157 million Mg of contaminated sediment is stored along the Big River, with 92% of it located in floodplain deposits that are typically contaminated to depths of 1.5-3.5 m. These contaminated sediments store a total of 188,549 Mg of Pb and 34,299 Mg of Zn, of which 98% of the Pb and 95% of the Zn are stored in floodplain deposits. Most of the metal mass in channel deposits is stored near the mines, with 72% of the Pb and 78% of the Zn occurring in the 25 km of channel proximal to the mine source. Although environmental assessments of streams contaminated by mines often focus on evaluating metal concentrations in the geochemically active fine sediment fractions, about 60% of the Pb stored in channels is associated with coarse dolomite tailings fragments deposited in channels within 25 km of the mines. The magnitude and basinwide distribution of Pb and Zn storage in legacy floodplain sediments ensures that remobilization by bank erosion will be a continuing problem for water quality far into the future.

Exchangeable lead from prediction models relates to vetiver lead uptake in different soil types.

PubMed

Andra, Syam S; Sarkar, Dibyendu; Saminathan, Sumathi K M; Datta, Rupali

2011-12-01

Prediction models for exchangeable soil lead, published earlier in this journal (Andra et al. 2010a), were developed using a suite of native lead (Pb) paint-contaminated residential soils from two US cities heavily populated with homes constructed prior to Pb ban in paints. In this study, we tested the feasibility and practical applications of these prediction models for developing a phytoremediation design using vetiver grass (Vetiveria zizanioides), a Pb-tolerant plant. The models were used to estimate the exchangeable fraction of Pb available for vetiver uptake in four lead-spiked soil types, both acidic and alkaline, with varying physico-chemical properties and that are different from those used to build the prediction models. Results indicate a strong correlation for predictable exchangeable Pb with the observed fraction and as well with total Pb accumulated by vetiver grass grown in these soils. The correlation coefficient for the predicted vs. observed exchangeable Pb with p < 0.001 was 0.999, 0.996, 0.949, and 0.998 in the Immokalee, Millhopper, Pahokee Muck, and Tobosa soil type, respectively. Similarly, the correlation coefficient for the predicted exchangeable Pb vs. accumulated Pb in vetiver grass with p < 0.001 was 0.948, 0.983, 0.929, and 0.969 for each soil type, respectively. This study suggests that the success of a phytoremediation design could be assessed upfront by predicting the exchangeable Pb fraction in a given soil type based on its properties. This helps in modifying the soil conditions to enhance phytoextraction of Pb from contaminated soils.

A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA.

PubMed

Drexler, Judith Z; Alpers, Charles N; Neymark, Leonid A; Paces, James B; Taylor, Howard E; Fuller, Christopher C

2016-05-01

In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon and (210)Pb. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0μgg(-1)and from 6.9 to 71ngg(-1), respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850CE), when concentrations reached their highest levels (74μgg(-1) Pb, 990ngg(-1) Hg; PbEF=12 and HgEF=28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in changes in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and subsequent fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425CE, it has received Pb and Hg contamination from both global and regional sources. Published by Elsevier B.V.

A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA

USGS Publications Warehouse

Drexler, Judith; Alpers, Charles N.; Neymark, Leonid; Paces, James B.; Taylor, Howard E.; Fuller, Christopher C.

2016-01-01

In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon, 210Pb, and 137Cs. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 µg g-1and from 6.9 to 71 ng g-1, respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850 CE), when concentrations reached their highest levels (74 µg g-1 Pb, 990 ng g-1 Hg; PbEF = 12 and HgEF = 28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425 CE, it has received Pb and Hg contamination from both global and regional sources.

Lead bioaccumulation in Opuntia ficus-indica following foliar or root exposure to lead-bearing apatite.

PubMed

El Hayek, Eliane; El Samrani, Antoine; Lartiges, Bruno; Kazpard, Veronique; Aigouy, Thierry

2017-01-01

The contamination of edible leafy vegetables by atmospheric heavy metal-bearing particles is a major issue in environmental toxicology. In this study, the uptake of lead by cladodes of Opuntia ficus-indica (Ofi), traditionally used in Mexican cuisine and in livestock fodder, is investigated after a 4-months exposure of either cladodes or roots to synthetic Pb-fluorapatite particles. Atomic Absorption Spectroscopy (AAS) for the quantitative analysis of Pb levels, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDX) for the examination of the cladode surface and fate of particles, and Micro-X-ray fluorescence (μXRF) measurements for elemental mapping of Pb in cladodes, were used. The results evidence that foliar contamination may be a major pathway for the transfer of Pb within Ofi cladodes. The stomata, areoles, and cuticle of cladode surface, play an obvious role in the retention and the incorporation of lead-bearing apatite, thus revealing the hazard of eating contaminated cladodes. The possibility of using series of successive cladodes for biomonitoring the atmospheric pollution in arid and semi-arid regions is also rapidly discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Redistribution of fractions of zinc, cadmium, nickel, copper, and lead in contaminated calcareous soils treated with EDTA.

PubMed

Jalali, Mohsen; Khanlari, Zahra V

2007-11-01

Effect of ethylene diamine tetraacetic acid (EDTA) on the fractionation of zinc (Zn), cadmium (Cd), nickel (Ni), copper (Cu), and lead (Pb) in contaminated calcareous soils was investigated. Soil samples containing variable levels of contamination, from 105.9 to 5803 mg/kg Zn, from 2.2 to 1361 mg/kg Cd, from 31 to 64.0 mg/kg Ni, from 24 to 84 mg/kg Cu, and from 109 to 24,850 mg/kg Pb, were subjected to EDTA treatment at different dosages of 0, 1.0, and 2.0 g/kg. Metals in the incubated soils were fractionated after 5 months by a sequential extraction procedure, in which the metal fractions were experimentally defined as exchangeable (EXCH), carbonate (CARB), Mn oxide (MNO), Fe oxide (FEO), organic matter (OM), and residual (RES) fractions. In contaminated soils without EDTA addition, Zn, Ni, Cu, and Pb were predominately present in the RES fraction, up to 60.0%, 32.3%, 41.1%, and 36.8%, respectively. In general, with the EDTA addition, the EXCH and CARB fractions of these metals increased dramatically while the OM fraction decreased. The Zn, Ni, Cu, and Pb were distributed mostly in RES, OM, FEO, and CARB fractions in contaminated soils, but Cd was found predominately in the CARB, MNO, and RES fractions. The OM fraction decreased with increasing amounts of EDTA. In the contaminated soils, EDTA removed some Pb, Zn, Cu, and Ni from MNO, FEO, and OM fractions and redistributed them into CARB and EXCH fractions. Based on the relative percent in the EXCH and CARB fractions, the order of solubility was Cd > Pb > Ni > Cu > Zn for contaminated soils, before adding of EDTA, and after adding of EDTA, the order of solubility was Pb > Cd > Zn > Ni > Cu. The risk of groundwater contamination will increase after applying EDTA and it needed to be used very carefully.

Effects of dietary Pb on accumulation, histopathology, and digestive enzyme activities in the digestive system of tilapia (Oreochromis niloticus).

PubMed

Dai, Wei; Du, Huahua; Fu, Linglin; Jin, Chengguan; Xu, Zirong; Liu, Huitao

2009-02-01

With the increasing occurrence of dietary lead (Pb) contamination in aquatic environment, threat of the dietary Pb toxicity to aquatic organisms attracted more attention. In this study, after being exposed to dietary Pb at concentrations of 0, 100, 400, and 800-microg/g dry weight for 60 days, the groups of tilapia (Oreochromis niloticus) were sacrificed and sampled to analyze the effects of dietary Pb on accumulation, histopathology, and digestive enzyme activities in tissues of the digestive system. The results showed that the Pb accumulation in tissues increased with the dietary Pb concentrations. Moreover, Pb accumulated in sampled tissues in the following order: intestine > stomach > liver. By observation of liver histological sections in optical microscope, lesions could be detected in the Pb-contaminated groups. It was also demonstrated that the inhibitory effect of dietary Pb on digestive enzyme activities was dietary Pb concentration dependent. Different degrees of inhibition of enzyme activities were exhibited in sampled tissues. It was indicated that digestive enzyme activities in the digestive system might be considered as the potential biomarkers of dietary Pb contamination in tilapia.

Amending soils with phosphate as means to mitigate soil lead hazard: a critical review of the state of the science.

PubMed

Scheckel, Kirk G; Diamond, Gary L; Burgess, Michele F; Klotzbach, Julie M; Maddaloni, Mark; Miller, Bradley W; Partridge, Charles R; Serda, Sophia M

2013-01-01

Ingested soil and surface dust may be important contributors to elevated blood lead (Pb) levels in children exposed to Pb contaminated environments. Mitigation strategies have typically focused on excavation and removal of the contaminated soil. However, this is not always feasible for addressing widely disseminated contamination in populated areas often encountered in urban environments. The rationale for amending soils with phosphate is that phosphate will promote formation of highly insoluble Pb species (e.g., pyromorphite minerals) in soil, which will remain insoluble after ingestion and, therefore, inaccessible to absorption mechanisms in the gastrointestinal tract (GIT). Amending soil with phosphate might potentially be used in combination with other methods that reduce contact with or migration of contaminated soils, such as covering the soil with a green cap such as sod, clean soil with mulch, raised garden beds, or gravel. These remediation strategies may be less expensive and far less disruptive than excavation and removal of soil. This review evaluates evidence for efficacy of phosphate amendments for decreasing soil Pb bioavailability. Evidence is reviewed for (1) physical and chemical interactions of Pb and phosphate that would be expected to influence bioavailability, (2) effects of phosphate amendments on soil Pb bioaccessibility (i.e., predicted solubility of Pb in the GIT), and (3) results of bioavailability bioassays of amended soils conducted in humans and animal models. Practical implementation issues, such as criteria and methods for evaluating efficacy, and potential effects of phosphate on mobility and bioavailability of co-contaminants in soil are also discussed.

Total and Bioaccessible Soil Arsenic and Lead Levels and Plant Uptake in Three Urban Community Gardens in Puerto Rico

EPA Science Inventory

Arsenic (As) and lead (Pb) are two contaminants of concern associated with urban gardening. In Puerto Rico, data currently is limited on As and Pb levels in urban garden soils, soil metal (loid) bioaccessibility, and uptake of As and Pb in soil by edible plants grown in the regio...

Pb2+ ions mobility perturbation by iron particles during electrokinetic remediation of contaminated soil.

PubMed

Zulfiqar, Waqas; Iqbal, Muhammad Asad; Butt, Mehwish Khalid

2017-02-01

Electrokinetic (EK) remediation is one of the most useful approaches for de-contamination of soils. However, it is unclear that how and when the electrokinetic remediation gives advantages over other remediation techniques in soil. This study was designed to find the influence of Fe 2+ particles on the mobility of Pb 2+ ions, during electrokinetic remediation, in soil contaminated purposely by lead nitrate Pb(NO 3 ) 2 . Two types of electrokinetic experiments were performed, by using iron and graphite electrodes. The Fe 2+ ions from the iron electrodes, produced due to acidic environment in anode compartment, affected the mobility of lead particles by precipitating as Fe(OH) 2 . Fe 2+ ions enhance the adsorption of lead ions in soil. The results show Fe 2+ ions of lower ionic conductivity decreased mobility of other particles in soil. Electrokinetic remediation for up to 120 h with iron electrodes is shown to be less effective for removal of lead. In contrast, graphite electrodes were 15 times more effective in lead removal from soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bamboo- and pig-derived biochars reduce leaching losses of dibutyl phthalate, cadmium, and lead from co-contaminated soils.

PubMed

Qin, Peng; Wang, Hailong; Yang, Xing; He, Lizhi; Müller, Karin; Shaheen, Sabry M; Xu, Song; Rinklebe, Jörg; Tsang, Daniel C W; Ok, Yong Sik; Bolan, Nanthi; Song, Zhaoliang; Che, Lei; Xu, Xiaoya

2018-05-01

Biochar effect on the potential mobility of dibutyl phthalate (DBP), cadmium (Cd), and lead (Pb) in co-contaminated soils is not well investigated. A laboratory leaching study was conducted to evaluate the effect of biochars derived from bamboo (BB) and pig (PB) on the leachability of DBP, Cd, and Pb through soil columns packed with two soils with low or high organic carbon content (LOC; 0.35% C: HOC; 2.24% C) and spiked with DBP, Cd, and Pb. Application of PB to the LOC soil significantly (P < 0.05) reduced the leaching loss by up to 88% for DBP, 38% for Cd, and 71% for Pb, whereas its impact was insignificant in the HOC soil. The higher efficacy of PB in reducing the leaching of DBP, Cd, and Pb in the LOC soil than that of BB might be related to PB's higher specific surface area, surface alkalinity, pH, and mineral contents compared to those of BB. Co-contamination of Cd and Pb enhanced leaching of DBP in the LOC soil treated with PB, possibly by competition for the sorption sites. Leaching of DBP, Cd, and Pb were significantly (P < 0.05) higher in the LOC soil than in the HOC soil. This study revealed that the effectiveness of biochars was dependent on the soil organic carbon content. Application of PB to the LOC soil was effective in reducing the leaching risk of DBP, Cd, and Pb. Copyright © 2018 Elsevier Ltd. All rights reserved.

FORMATION OF CHLOROPYROMORPHITE FROM GALENA (PBS) IN THE PRESENCE OF HYDROXYAPATITE

EPA Science Inventory

Transformation of unstable lead [Pb(II)] forms into insoluble pyromorphite, [Pb5(PO4)3(OH, Cl, F...)], by addition of phosphate to Pb contaminated soil has been proposed as a remediation technology which reduces the mobility and bioavailability of Pb. Under aerobic condition, ox...

Lead excretion in milk of accidentally exposed dairy cattle.

PubMed

Bischoff, Karyn; Higgins, William; Thompson, Belinda; Ebel, Joseph G

2014-01-01

Lead (Pb) exposure in dairy cattle is associated with economic losses due to mortality and treatment costs, but with production animals there is also risk to the human food chain. The first objective of this study was to quantify the Pb concentration in milk from Pb-exposed cattle. The second objective was to correlate blood and milk Pb concentrations from individual cows. The third objective was long-term monitoring to determine the duration of milk contamination after exposure ceased. A dairy herd of more than 100 cows was accidentally exposed to Pb-contaminated feed. Milk and blood were collected for Pb analysis. Serial collection of milk samples continued for 2.5 years. The initial concentration of Pb in bulk tank milk was 0.0999 mg l⁻¹. The highest milk Pb concentration from an individual cow was 0.4657 mg l⁻¹ and the highest blood Pb concentration was 1.216 mg l⁻¹. One milk sample collected at the end of the study (day 922) contained 0.0117 mg Pb l⁻¹ of Pb. The calculated relationship between milk (y) and blood (x) Pb concentration was ln(y) = 3.4(x) - 2.21 (R² = 0.98).

Synergistic effect of chelators and Herbaspirillum sp. GW103 on lead phytoextraction and its induced oxidative stress in Zea mays.

PubMed

Govarthanan, Muthusamy; Kamala-Kannan, Seralathan; Kim, Seol Ah; Seo, Young-Seok; Park, Jung-Hee; Oh, Byung-Taek

2016-10-01

Phytoremediation is an in situ, low-cost strategy for cleanup of the sites contaminated with heavy metals. Experiments were conducted to assess the impact of synthetic chelators and plant growth-promoting rhizosphere bacteria (Herbaspirillum sp. GW103) on heavy metal lead (Pb) uptake in Z. mays cultivated in Pb-contaminated soil. The present study investigated the Pb phytoaccumulation rate and plant antioxidant enzyme activities in Z. mays exposed to 100 mg/kg of PbNO3. The combination of gluconic acid (GA) with Herbaspirillum sp. GW103 treatment showed higher Pb solubility (18.9 mg/kg) compared with other chelators. The chemical chelators showed the significant difference in phytoaccumulation as well as antioxidant enzyme activities. The antioxidant enzymes such as catalase, peroxidase and superoxide dismutase activities changed under Pb stress. The study indicated that increased activity of antioxidant enzymes may play as signal inducers to fight against Pb.

Ethylenediaminedisuccinic acid (EDDS) enhances phytoextraction of lead by vetiver grass from contaminated residential soils in a panel study in the field.

PubMed

Attinti, Ramesh; Barrett, Kirk R; Datta, Rupali; Sarkar, Dibyendu

2017-06-01

Phytoextraction is a green remediation technology for cleaning contaminated soils. Application of chelating agents increases metal solubility and enhances phytoextraction. Following a successful greenhouse experiment, a panel study under field weather elucidated the efficiency of the chelating agent ethylenediaminedisuccinic acid (EDDS) on phytoextraction of lead (Pb) by vetiver grass, a hyperaccumulator of Pb, and a nonaccumulator fescue grass from residential soils contaminated with Pb-based paint from Baltimore, MD and San Antonio, TX. Three soils from each city with Pb content between 1000 and 2400 mg kg -1 were chosen for the panel study. Sequential extraction revealed that Fe-Mn oxide (60-63%) and carbonate (25-33%) fractions of Pb dominated in Baltimore soils, whereas in San Antonio soils, Pb was primarily bound to the organic fraction (64-70%) because organic content was greater and, secondarily, to the Fe-Mn oxide (15-20%) fraction. Vetiver and fescue grasses were transplanted and grown on wood panels in the field with EDDS applied after 3 months and 13 months. Soil and leachate results indicated that EDDS applications increased Pb solubility in soils. Plant tissues results indicated enhanced the uptake of Pb by vetiver and showed that EDDS application promoted translocation of Pb from root to shoot. Average Pb concentration increased by 53% and 203% in shoots and by 73% and 84% in roots of vetiver after the first and second applications of EDDS, respectively. Concentrations in roots and shoots increased in all tested soils, regardless of soil pH or clay content. After the second application, average Pb concentrations in vetiver were higher than those in fescue by 3.6x in shoots and 8.3x in roots. Visual phytotoxic symptoms from increased bioavailable Pb from EDSS applications were observed in fescue but not in vetiver. This study demonstrated the potential of a chemically-catalyzed phytoremediation system as a cleanup method for lead-contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Graphic and algebraic solutions of the discordant lead-uranium age problem

USGS Publications Warehouse

Stieff, L.R.; Stern, T.W.

1961-01-01

Uranium-bearing minerals that give lead-uranium and lead-lead ages that are essentially in agreement, i.e. concordant, generally are considered to have had a relatively simple geologic history and to have been unaltered since their deposition. The concordant ages obtained on such materials are, therefore, assumed to approach closely the actual age of the minerals. Many uranium-bearing samples, particularly uranium ores, give the following discordant age sequences; Pb206 U238 < Pb207 U235 ??? Pb207 Pb206 or, less frequently, Pb207 Pb206 ??? Pb207 U235 < Pb206 U238. These discordant age sequences have been attributed most often to uncertainties in the common lead correction, selective loss of radio-active daughter products, loss or gain of lead or uranium, or contamination by an older generation of radiogenic lead. The evaluation of discordant lead isotope age data may be separated into two operations. The first operation, with which this paper is concerned, is mechanical in nature and involves the calculation of the different possible concordant ages corresponding to the various processes assumed to have produced the discordant ages. The second operation is more difficult to define and requires, in part, some personal judgement. It includes a synthesis of the possible concordant age solutions with other independent geologic and isotopic evidence. The concordant age ultimately chosen as most acceptable should be consistent not only with the known events in the geologic history of the area, the age relations of the enclosing rocks, and the mineralogic and paragenetic evidence, but also with other independent age measurements and the isotopic data obtained on the lead in related or associated non-radioactive minerals. The calculation of the possible concordant ages from discordant age data has been greatly simplified by Wetherill's graphical method of plotting the mole ratios of radiogenic Pb206 U238 ( N206 N238) vs. radiogenic Pb207 U235 ( N207 N235) after correcting for the contaminating common Pb206 and Pb207. The linear relationships noted in this graphical procedure have been extended to plots of the mole ratios of total Pb206 U238 ( tN206 N238) vs. total Pb207 U235 ( tN207 N235). This modification permits the calculation of concordant ages for unaltered samples using only the Pb207 Pb206 ratio of the contaminating common lead. If isotopic data are available for two samples of the same age, x and y, from the same or related deposits or outcrops, graphs of the normalized difference ratios [ ( N206 N204)x - ( N206 N204)y ( N238 N204)x -( N238 N204)y] vs. [ ( N207 N204)x - ( N207 N204)y ( N235 N204)x -( N235 N204)y] can give concordant ages corrected for unknown amounts of a common lead with an unknown Pb207/ Pb206 ratio. (If thorium is absent the difference ratios may be normalized with the more abundant index isotope, Pb208.) Similar plots of tho normalized, difference ratios for three genetically related samples (x - y) and(x - z), will give concordant ages corrected, in addition, for either one unknown period of past alteration or initial contamination by an older generation of radiogenic lead of unknown Pb207/Pb206 ratio. Practical numerical solutions for many of tho concordant age calculations are not currently available. However, the algebraic equivalents of these new graphical methods give equations which may be programmed for computing machines. For geologically probable parameters the equations of higher order have two positive real roots that rapidly converge on the exact concordant ages corrected for original radiogenic lead and for loss or gain of lead or uranium. Modifications of these general age equations expanded only to the second degree have been derived for use with desk calculators. These graphical and algebraic methods clearly suggest both the type and minimum number of samples necessary for adequate mathematical analysis of discordant lead isotope age data. This mathematical treatment also makes it clear t

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

PubMed

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

2009-11-15

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

[Leaching Remediation of Copper and Lead Contaminated Lou Soil by Saponin Under Different Conditions].

PubMed

Deng, Hong-xia; Yang, Ya-li; Li, Zhen; Xu, Yan; Li, Rong-hua; Meng, Zhao-fu; Yang, Ya-ti

2015-04-01

In order to investigate the leaching remediation effect of the eco-friendly biosurfactant saponin for Cu and Pb in contaminated Lou soil, batch tests method was used to study the leaching effect of saponin solution on single Cu, Pb contaminated Lou soil and mixed Cu and Pb contaminated Lou soil under different conditions such as reaction time, mass concentration of saponin, pH, concentration of background electrolyte and leaching times. The results showed that the maximum leaching removal effect of Cu and Pb in contaminated Lou soil was achieved by complexation of the heavy metals with saponin micelle, when the mass concentration of saponin solution was 50 g x L(-1), pH was 5.0, the reaction time was 240 min, and there was no background electrolyte. In single and mixed contaminated Lou soil, the leaching percentages of Cu were 29.02% and 25.09% after a single leaching with 50 g x L(-1) saponin under optimal condition, while the single leaching percentages of Pb were 31.56% and 28.03%, respectively. The result indicated the removal efficiency of Pb was more significant than that of Cu. After 4 times of leaching, the cumulative leaching percentages of Cu reached 58.92% and 53.11%, while the cumulative leaching percentages of Pb reached 77.69% and 65.32% for single and mixed contaminated Lou soil, respectively. The fractionation results of heavy metals in soil before and after a single leaching showed that the contents of adsorbed and exchangeable Cu and Pb increased in the contaminated soil, while the carbonate-bound, organic bound and sulfide residual Cu and Pb in the contaminated Lou soil could be effectively removed by saponin.

Nutrient leaching, soil pH and changes in microbial community increase with time in lead-contaminated boreal forest soil at a shooting range area.

PubMed

Selonen, Salla; Setälä, Heikki

2017-02-01

Despite the known toxicity of lead (Pb), Pb pellets are widely used at shotgun shooting ranges over the world. However, the impacts of Pb on soil nutrients and soil microbes, playing a crucial role in nutrient cycling, are poorly understood. Furthermore, it is unknown whether these impacts change with time after the cessation of shooting. To shed light on these issues, three study sites in the same coniferous forest in a shooting range area were studied: an uncontaminated control site and an active and an abandoned shooting range, both sharing a similar Pb pellet load in the soil, but the latter with a 20-year longer contamination history. Soil pH and nitrate concentration increased, whilst soil phosphate concentration and fungal phospholipid fatty acid (PLFA) decreased due to Pb contamination. Our results imply that shooting-derived Pb can influence soil nutrients and microbes not only directly but also indirectly by increasing soil pH. However, these mechanisms cannot be differentiated here. Many of the Pb-induced changes were most pronounced at the abandoned range, and nutrient leaching was increased only at that site. These results suggest that Pb disturbs the structure and functions of the soil system and impairs a crucial ecosystem service, the ability to retain nutrients. Furthermore, the risks of shooting-derived Pb to the environment increase with time.

Heavy metal contamination of a Greenland Fjord system by mine wastes

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

Loring, D.H.; Asmund, G.

Since 1973, about 500,000 tons/yr of metal-rich particulate tailings from a lead/zinc flotation mill have been discharged through a submarine outfall into a two-fjord system on the west coast of Greenland. Differential solubilization of particulate metals by seawater, seasonal water mixing, and sill exchange tailings dispersal processes have resulted in high, but seasonally variable, Zn, Cd, and Pb contamination of the water and suspended particulate matter (SPM). Chemical partition of the SPM shows that most of the Pb, but relatively low proportions of Zn and Cd are weakly bound to the SPM. Such particulate metal characteristics allow the real timemore » effects of tailings discharges and dispersal on the system to be traced even in the sediments where tailings accumulation is very slow. Fjord seaweeds and blue mussels also contain varying amounts of Zn, Pb, and Cd, depending on the metal and their location relative to the tailings outfall. They apparently responded almost instantly to the metal contamination as did the water and SPM. High Pb concentrations in the fjord mussels most likely derive from the preferential uptake of available particulate Pb, whereas the seaweeds appear to derive most of their heavy metal concentrations from the dissolved phase. The evidence from this and other sites, and from experimental work, indicates that any discharge of Pb-particles into the marine environment, either directly as mine wastes or indirectly from natural runoff from current and former lead mining sites, results in immediate lead contamination of the in situ mussel population. 20 refs., 4 figs., 5 tab.« less

Food safety of milk and dairy product of dairy cattle from heavy metal contamination

NASA Astrophysics Data System (ADS)

Harlia, E.; Rahmah, KN; Suryanto, D.

2018-01-01

Food safety of milk and dairy products is a prerequisite for consumption, which must be free from physical, biological and chemical contamination. Chemical contamination of heavy metals Pb (Plumbum/Lead) and Cd (Cadmium) is generally derived from the environment such as from water, grass, feed additives, medicines and farm equipment. The contamination of milk and dairy products can affect quality and food safety for human consumption. The aim of this research is to investigate contamination of heavy metals Pb and Cd on fresh milk, pasteurized milk, and dodol milk compared with the Maximum Residue Limits (MRL). The methods of this researched was through case study and data obtained analyzed descriptively. Milk samples were obtained from Bandung and surrounding areas. The number of samples used was 30 samples for each product: 30 samples of fresh milk directly obtained from dairy farm, 30 samples of pasteurized milk obtained from street vendors and 30 samples of dodol milk obtained from home industry. Parameters observed were heavy metal residues of Pb and Cd. The results showed that: 1) approximately 83% of fresh milk samples were contaminated by Pb which 57% samples were above MRL and 90% samples were contaminated by Cd above MRL; 2) 67% of pasteurized milk samples were contaminated by Pb below MRL; 3) 60% of dodol milk samples were contaminated by Pb and Cd above MRL.

Transformation and bioaccessibility of lead induced by steamed bread feed in the gastrointestinal tract.

PubMed

Kan, Junhong; Sima, Jingke; Cao, Xinde

2017-03-01

Accidental ingestion of contaminated soil has been recognized as an important pathway of human exposure to lead (Pb), especially for children through hand-to-mouth activities. Intake of food following the soil ingestion may affect the bioaccessibility of Pb in the gastrointestinal tract. In this study, the effect of steamed bread on the transformation and subsequent bioaccessibility of Pb in two soils was determined by the physiologically based extraction test (PBET). Two compounds, Pb(NO 3 ) 2 and PbCO 3 , were included in the evaluation for comparison. In the gastric phase, Pb bioaccessibility decreased as the steamed bread increased due to the sorption of Pb on the undissolved steamed bread, especially in PbCO 3 , Pb bioaccessibility decreased from 95.03% to 85.40%. Whereas in the intestinal phase, Pb bioaccessibility increased from 1.85% to 5.66% and from 0.89% to 1.80% for Pb(NO 3 ) 2 and PbCO 3 , respectively. The increase was attributed to the transformation of formed Pb carbonates into soluble organic-Pb complexes induced by the dissolved steamed bread at neutral pH as indicated by MINTEQ modeling. For the PbCO 3 -contaminated soil, the change in Pb bioaccessibility in both gastric and intestinal phases behaved like that in the pure PbCO 3 compound, the steamed bread increased the bioaccessibility of Pb in the intestinal phase, but the decreased bioaccessibility of Pb was observed in the gastric phase after the steamed bread was added. However, in the soil contaminated with free Pb 2+ or sorbed Pb forms, the steamed bread increased the Pb bioaccessibility in both gastric and intestinal phases. This was probably due to the higher dissolved organic carbon induced transformation of sorbed Pb (Pb sorbed by Fe/Mn oxides) into soluble Pb-organic complex. Results from this study indicated that steamed bread had an influence on the Pb speciation transformation, correspondingly affecting Pb bioaccessibility in the gastrointestinal tract. Copyright © 2016. Published by Elsevier Inc.

Effect of alkyl polyglucoside and nitrilotriacetic acid combined application on lead/pyrene bioavailability and dehydrogenase activity in co-contaminated soils.

PubMed

Chen, Tingru; Liu, Xiaoyan; Zhang, Xinying; Chen, Xiao; Tao, Kaiyun; Hu, Xiaoxin

2016-07-01

At present, few research focus on the phytoremediation for organic pollutants and heavy metals enhanced by surfactants and chelate agents in the combined contaminated soils or sediments. In this study, the effect of a novel combined addition of alkyl polyglucoside (APG) and nitrilotriacetic acid (NTA) into pyrene and lead (Pb) co-contaminated soils on bioaccessiblity of pyrene/Pb and dehydrogenase activities (DHA) was studied. Through the comparison of the results with the alone and combined application, synergistic effect on bioaccessiblity of pyrene and Pb was found while APG and NTA was applied together. Results also indicated a significant promotion on the DHA in mixed addition of APG and NTA. In addition, correlation and principal component analysis were performed to better understand the relationship among APG/NTA, bioaccessiblity of pyrene/Pb and the DHA. Results showed that APG and NTA can affect DHA directly by themselves but also can affect DHA indirectly by changing bioaccessible pyrene and exchangeable Pb. Copyright © 2016 Elsevier Ltd. All rights reserved.

In situ remediation and phytotoxicity assessment of lead-contaminated soil by biochar-supported nHAP.

PubMed

Yang, Zhangmei; Fang, Zhanqiang; Tsang, Pokeung Eric; Fang, Jianzhang; Zhao, Dongye

2016-11-01

In this study, a kind of biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in in-situ remediation of lead-contaminated soil. Column experiments were performed to compare the mobility of nHAP@BC and Bare-nHAP. The immobilization, accumulation and toxic effects of Pb in the after-amended soil were assessed by the in vitro toxicity tests and pot experiments. The column experiments showed a significant improvement in the mobility of nHAP@BC. The immobilization rate of Pb in the soil was 74.8% after nHAP@BC remediation. Sequential extraction procedures revealed that the residual fraction of Pb increased by 66.6% after nHAP@BC remediation, which greatly reduced the bioavailability of Pb in the soil. In addition, pot experiments indicated that nHAP@BC could effectively reduce the upward translocation capacity of Pb in a soil-plant system. The concentration of Pb in the aerial part of the cabbage mustard was 0.1 mg/kg, which is lower than the tolerance limit (0.3 mg/kg). nHAP@BC can remediate Pb-contaminated soil effectively, which can restore soil quality for planting. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced bioremediation of lead-contaminated soil by Solanum nigrum L. with Mucor circinelloides.

PubMed

Sun, Liqun; Cao, Xiufeng; Li, Min; Zhang, Xu; Li, Xinxin; Cui, Zhaojie

2017-04-01

Strain selected from mine tailings in Anshan for Pb bioremediation was characterized at the genetic level by internal transcribed spacer (ITS) sequencing. Results revealed that the strain belongs to Mucor circinelloides. Bioremediation of lead-contaminated soil was conducted using Solanum nigrum L. combined with M. circinelloides. The removal efficacy was in the order microbial/phytoremediation > phytoremediation > microbial remediation > control. The bioremediation rates were 58.6, 47.2, and 40.2% in microbial/phytoremediation, microbial remediation, and phytoremediation groups, respectively. Inoculating soil with M. circinelloides enhanced Pb removal and S. nigrum L. growth. The bioaccumulation factor (BF, 1.43), enrichment factor (EF, 1.56), and translocation factor (TF, 1.35) were higher than unit, suggesting an efficient ability of S. nigrum L. in Pb bioremediation. Soil fertility was increased after bioremediation according to change in enzyme activities. The results indicated that inoculating S. nigrum L. with M. circinelloides enhanced its efficiency for phytoremediation of soil contaminated with Pb.

TREATMENT OF CONTAMINATED SOIL WITH PHOSPHORUS AND MANGANESE OXIDE REDUCES LEAD ADSORPTION BY SPRAGUE-DAWLEY RATS

EPA Science Inventory

A study was conducted to determine the extent of adsorption of Pb into young rats that were fed Pb contaminated soil treated with two different sources of P and P plus Mn oxide. Attempts were also made to compare an in vitro, physiologically based extraction procedure test (PBET)...

Lead exposure and poisoning of songbirds using the Coeur d'Alene River Basin, Idaho, USA.

PubMed

Hansen, James A; Audet, Daniel; Spears, Brian L; Healy, Kate A; Brazzle, Roy E; Hoffman, David J; Dailey, Anne; Beyer, W Nelson

2011-10-01

Previous studies have found widespread Pb poisoning of waterfowl in the Coeur d'Alene River Basin in northern Idaho, USA, which has been contaminated by mining and smelting activities. We studied the exposure of ground-feeding songbirds to Pb, sampling 204 American robins (Turdus migratorius), song sparrows (Melospiza melodia), and Swainson's thrushes (Catharus ustulatus) throughout the basin. These songbirds had mean blood Pb concentrations (mg/kg, dry weight) of less than 0.19 at a reference area (25 mg Pb/kg soil), 1.09 at moderately contaminated sites (170 to 1300 mg Pb/kg soil), and 2.06 at highly contaminated sites (2000 to 5000 mg Pb/kg soil). Based on guidelines for evaluating blood Pb in birds, 6% of robins from the highly contaminated sites had background concentrations, 24% were subclinically poisoned, 52% were clinically poisoned, and 18% were severely clinically poisoned with Pb. Blood Pb concentrations were lower in song sparrows than in robins and lowest in Swainson's thrushes. More than half of the robins and song sparrows from all contaminated sites and more than half of the Swainson's thrushes from highly contaminated sites showed at least 50% inhibition of the activity of the enzyme δ-aminolevulinic acid dehydratase (ALAD), commonly used as a measure of exposure to Pb. The highest hepatic Pb concentration of 61 mg/kg (dry weight) was detected in a song sparrow. Using Al as a marker for soil in songbird ingesta, we estimated average soil ingestion rates as 20% in robins, 17% in song sparrows, and 0.7% in Swainson's thrushes. Soil Pb in ingesta accounted for almost all of the songbirds' exposure to Pb. Based on these results, it is recommended that ecological risk assessments of ground-feeding songbirds at contaminated sites include soil ingestion as a pathway of exposure to Pb. Copyright © 2011 SETAC.

Lead exposure and poisoning of songbirds using the Coeur d'Alene River Basin, Idaho

USGS Publications Warehouse

Hansen, James A.; Audet, Daniel; Spears, Brian L.; Healy, Kate A.; Brazzle, Roy E.; Hoffman, David J.; Dailey, Anne; Beyer, W. Nelson

2011-01-01

Previous studies have found widespread Pb poisoning of waterfowl in the Coeur d'Alene River Basin in northern Idaho, USA, which has been contaminated by mining and smelting activities. We studied the exposure of ground-feeding songbirds to Pb, sampling 204 American robins (Turdus migratorius), song sparrows (Melospiza melodia), and Swainson's thrushes (Catharus ustulatus) throughout the basin. These songbirds had mean blood Pb concentrations (mg/kg, dry weight) of less than 0.19 at a reference area (25 mg Pb/kg soil), 1.09 at moderately contaminated sites (170 to 1300 mg Pb/kg soil), and 2.06 at highly contaminated sites (2000 to 5000 mg Pb/kg soil). Based on guidelines for evaluating blood Pb in birds, 6% of robins from the highly contaminated sites had background concentrations, 24% were subclinically poisoned, 52% were clinically poisoned, and 18% were severely clinically poisoned with Pb. Blood Pb concentrations were lower in song sparrows than in robins and lowest in Swainson's thrushes. More than half of the robins and song sparrows from all contaminated sites and more than half of the Swainson's thrushes from highly contaminated sites showed at least 50% inhibition of the activity of the enzyme δ-aminolevulinic acid dehydratase (ALAD), commonly used as a measure of exposure to Pb. The highest hepatic Pb concentration of 61 mg/kg (dry weight) was detected in a song sparrow. Using Al as a marker for soil in songbird ingesta, we estimated average soil ingestion rates as 20% in robins, 17% in song sparrows, and 0.7% in Swainson's thrushes. Soil Pb in ingesta accounted for almost all of the songbirds' exposure to Pb. Based on these results, it is recommended that ecological risk assessments of ground-feeding songbirds at contaminated sites include soil ingestion as a pathway of exposure to Pb.

Soil solution interactions may limit Pb remediation using P amendments in an urban soil

EPA Science Inventory

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg^-1 was amended in a laboratory study with bone meal and triple super phospha...

Effects of lead shot ingestion on bone mineralization in a population of red-legged partridge (Alectoris rufa).

PubMed

Álvarez-Lloret, Pedro; Rodríguez-Navarro, Alejandro B; Romanek, Christopher S; Ferrandis, Pablo; Martínez-Haro, Mónica; Mateo, Rafael

2014-01-01

The effect of lead (Pb) toxicity on bone mineralization was investigated in a wild population of red-legged partridge (Alectoris rufa) inhabiting a farmland area contaminated with Pb-shot from recreational hunting activities in Albacete, a southeastern province of Spain. Femora from 40 specimens of red-legged partridge were analyzed for Pb by graphite furnace atomic absorption spectroscopy (GF-AAS), and for bone composition by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The FTIR and DRX data of bone were analyzed in detail to determine possible alterations in bone mineral chemistry and crystallinity due to Pb toxicity. Results showed a marked decrease in the degree of mineralization as Pb concentrations in bone tissue increased while XRD analyses showed that the crystallinity of apatite crystals increased with the Pb load in bone. These load-dependent effects are indicative that Pb contamination altered bone remodeling by reducing new bone mineral formation and demonstrate that bone quality is a sensitive indicator of adverse effects on wild bird populations exposed to Pb pollution. © 2013 Elsevier B.V. All rights reserved.

Soil pollution at outdoor shooting ranges: Health effects, bioavailability and best management practices.

PubMed

Fayiga, A O; Saha, U K

2016-09-01

The total lead (Pb) concentrations of the surface soil, sub surface soil, vegetation and surface waters of outdoor shooting ranges are extremely high and above regulatory limits. Lead is dangerous at high concentrations and can cause a variety of serious health problems. Shooters and range workers are exposed to lead dust and can even take Pb dust home to their families while some animals around the shooting range can ingest the Pb bullets. The toxicity of Pb depends on its bioavailability which has been determined to be influenced greatly by the geochemical properties of each site. The bioavailability of Pb in shooting ranges has been found to be higher than other metal contaminated soils probably because of its very low residual Pb (<1%). Despite being an immobile element in the soil, migration of Pb within shooting ranges and offsite has been reported in literature. Best management practices to reduce mobility of Pb in shooting ranges involve an integrated Pb management program which has been described in the paper. The adoption of the non-toxic "green bullet" which has been developed to replace Pb bullets may reduce or prevent environmental pollution at shooting ranges. However, the contaminated soil resulting from decades of operation of several shooting ranges still needs to be restored to its natural state. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Effects of exogenous iron on lead accumulation in Typha latifolia from a lead-contaminated soil].

PubMed

Zhong, Shun-Qing; Xu, Jian-Ming

2013-01-01

A pot experiment was conducted to study the effects of adding 100 and 500 mg x kg(-1) of exogenous iron (Fe) on the lead (Pb) accumulation in Typha latifolia growing on a soil with 0, 100, 500 and 1000 mg x kg(-1) of Pb, respectively. In treatment 500 mg Fe x kg(-1), the Pb concen tration in T. latifolia shoots and roots was higher, compared with that in treatment 100 mg Fe x kg(-1). When the soil Pb concentration was 1000 mg x kg(-1), the Pb concentration in T. lati folia shoots and roots in treatment 500 mg Fe x kg(-1) increased by 33.7% and 50.5%, respectively, compared with that in treatment 100 mg Fe x kg(-1). The exchangeable Pb concentration in rhizosphere soil was 77.0% -114.6% higher in treatment 500 mg Fe x kg(-1) than in treatment 100 mg Fe x kg(-1). When the soil Pb concentration was 0, 100 and 1000 mg x kg(-1), the root dry mass in treatment 500 mg Fe x kg(-1) had a significant decrease, compared with that in treatment 100 mg Fe x kg(-1). It was suggested that adding appropriate amount of Fe to Pb-contaminated wetland soil could increase the availability of soil Pb and improve the Pb accumulation in plants.

The influence of EDTA application on the interactions of cadmium, zinc, and lead and their uptake of rainbow pink (Dianthus chinensis).

PubMed

Lai, Hung-Yu; Chen, Zueng-Sang

2006-10-11

Soil used in this study was artificially contaminated with Cd, Zn, Pb, or applied in combinations (Cd-Zn, Cd-Pb, Zn-Pb, or Cd-Zn-Pb) to study the interactions of metals in soil contaminated with multiple metals. After planting rainbow pink (Dianthus chinensis) in these soils for 21 days, three different concentrations of ethylenedinitrilotetraacetic acid (EDTA) solutions were added to study the effect of applying EDTA on the interactions among these metals. The concentrations of Cd, Zn, and Pb in the soil solutions of different metals-treated soils increased significantly after applying 5 mmol EDTA kg(-1) soil (p<0.05). The potential of groundwater contamination will increase after applying EDTA and it is not recommended to be in situ used or have to use very carefully. The existence of Pb in the Cd-contaminated soil enhanced the uptake of Cd in rainbow pink in the treatments of control and 2 mmol EDTA kg(-1) soil. Cadmium inhibited the concentration of Zn without applying EDTA. However, whether the application of EDTA or not and the applied EDTA concentration had the greatest effect on the uptake of Pb when compared to Cd and Zn. After applying 5 mmol EDTA kg(-1) soil, Cd or Zn in the Pb-contaminated soil inhibited the uptake of Pb in rainbow pink, but there were no effect in other treatments.

Field demonstration of reduction of lead availability in soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings using phosphorus fertilizers*

PubMed Central

Xie, Zheng-miao; Wang, Bi-ling; Sun, Ye-fang; Li, Jing

2006-01-01

A field demonstration of reduction of lead availability in a soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings, located in Shaoxing, China was carried out to evaluate the effects of applications of phosphorus fertilizers on Pb fractionation and Pb phytoavailability in the soil. It was found that the addition of all three P fertilizers including single super phosphate (SSP), phosphate rock (PR), and calcium magnesium phosphate (CMP) significantly decreased the percentage of water-soluble and exchangeable (WE) soil Pb and then reduced the uptake of Pb, Cd, and Zn by the cabbage compared to the control (CK). The results showed that the level of 300 g P/m2 soil was the most cost-effective application rate of P fertilizers for reducing Pb availability at the first stage of remediation, and that at this P level, the effect of WE fraction of Pb in the soil decreased by three phosphorus fertilizers followed the order: CMP (79%)>SSP (41%)>PR (23%); Effectiveness on the reduction of Pb uptake by cabbage was in the order: CMP (53%)>SSP (41%)>PR (30%). Therefore our field trial demonstrated that it was effective and feasible to reduce Pb availability in soil and cabbage contaminated by mining tailings using P fertilizers in China and PR would be a most cost-effective amendment. PMID:16365925

Contamination history of lead and other trace metals reconstructed from an urban winter pond in the Eastern Mediterranean coast (Israel).

PubMed

Zohar, I; Bookman, R; Levin, N; de Stigter, H; Teutsch, N

2014-12-02

Pollution history of Pb and other trace metals was reconstructed for the first time for the Eastern Mediterranean, from a small urban winter pond (Dora, Netanya), located at the densely populated coastal plain of Israel. An integrated approach including geochemical, sedimentological, and historical analyses was employed to study sediments from the center of the pond. Profiles of metal concentrations (Pb, Zn, V, Ni, Cu, Cr, Co, Cd, and Hg) and Pb isotopic composition denote two main eras of pre- and post-19th century. The deeper sediment is characterized by low concentrations and relatively constant 206Pb/207Pb (around 1.20), similar to natural Pb sources, with slight indications of ancient anthropogenic activity. The upper sediment displays an upward increase in trace metal concentrations, with the highest enrichment factor for Pb (18.4). Lead fluxes and isotopic composition point to national/regional petrol-Pb emissions as the major contributor to Pb contamination, overwhelming other potential local and transboundary sources. Traffic-related metals are correlated with Pb, emphasizing the polluting inputs of traffic. The Hg profile, however, implies global pollution rather than local sources.

Cadmium and lead exposure associated with reduced growth rates, poorer fledging success of little blue heron chicks (Egretta caerulea) in south Louisiana wetlands.

PubMed

Spahn, S A; Sherry, T W

1999-10-01

Persistent contaminants in ecosystems are often monitored via organisms that bioaccumulate the pollutant of interest. Several published studies have used colonial wading birds to assess contamination by heavy metals in aquatic ecosystems. Using a nonlethal sampling regimen, this study identified chick feathers and guano as tissues that best reflect local contamination. Both cadmium and lead were detected in food samples (0.3-4.3 microg/g Cd, 0.8-9.3 microg/g Pb), guano (0.2-3.2 microg/g Cd, 1.0-9.5 microg/g Pb), and feathers (0.6-25.4 microg/g Cd, 1.2-16.9 microg/g Pb) from little blue heron chicks at levels similar to other studies. Chicks exposed to cadmium had significantly slower growth rates than nonexposed chicks, and exposure to lead was correlated with increased nestling mortality. The appropriate scale of comparison necessary to demonstrate these effects and the usefulness of wading birds as bioindicators are discussed.

Lead (Pb) isotopic fingerprinting and its applications in lead pollution studies in China: a review.

PubMed

Cheng, Hefa; Hu, Yuanan

2010-05-01

As the most widely scattered toxic metal in the world, the sources of lead (Pb) observed in contamination investigation are often difficult to identify. This review presents an overview of the principles, analysis, and applications of Pb isotopic fingerprinting in tracing the origins and transport pathways of Pb in the environment. It also summarizes the history and current status of lead pollution in China, and illustrates the power of Pb isotopic fingerprinting with examples of its recent applications in investigating the effectiveness of leaded gasoline phase-out on atmospheric lead pollution, and the sources of Pb found in various environmental media (plants, sediments, and aquatic organisms) in China. The limitations of Pb isotopic fingerprinting technique are discussed and a perspective on its development is also presented. Further methodological developments and more widespread instrument availability are expected to make isotopic fingerprinting one of the key tools in lead pollution investigation. Copyright 2009 Elsevier Ltd. All rights reserved.

First detection of lead in black paper from intraoral film: an environmental concern.

PubMed

Guedes, Débora F C; Silva, Reginaldo S; da Veiga, Márcia A M S; Pecora, Jesus D

2009-10-30

Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirão Preto, University of São Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 microg g(-1), 189 microg g(-1), 20.8 microg g(-1), and 54.0 microg g(-1), respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise.

New phosphate-based binder for stabilization of soils contaminated with heavy metals: leaching, strength and microstructure characterization.

PubMed

Du, Yan-Jun; Wei, Ming-Li; Reddy, Krishna R; Jin, Fei; Wu, Hao-Liang; Liu, Zhi-Bin

2014-12-15

Cement stabilization is used extensively to remediate soils contaminated with heavy metals. However, previous studies suggest that the elevated zinc (Zn) and lead (Pb) concentrations in the contaminated soils would substantially retard the cement hydration, leading to the deterioration of the performance of cement stabilized soils. This study presents a new binder, KMP, composed of oxalic acid-activated phosphate rock, monopotassium phosphate and reactive magnesia. The effectiveness of stabilization using this binder is investigated on soils spiked with Zn and Pb, individually and together. Several series of tests are conducted including toxicity characteristic leaching (TCLP), ecotoxicity in terms of luminescent bacteria test and unconfined compressive strength. The leachability of a field Zn- and Pb- contaminated soil stabilized with KMP is also evaluated by TCLP leaching test. The results show that the leached Zn concentrations are lower than the China MEP regulatory limit except when Zn and Pb coexist and for the curing time of 7 days. On the other hand, the leached Pb concentrations for stabilized soils with Pb alone or mixed Zn and Pb contamination are much lower than the China MEP or USEPA regulatory limit, irrespective of the curing time. The luminescent bacteria test results show that the toxicity of the stabilized soils has been reduced considerably and is classified as slightly toxic class. The unconfined compressive strength of the soils decrease with the increase in the Zn concentration. The stabilized soils with mixed Zn and Pb contaminants exhibit notably higher leached Zn concentration, while there is lower unconfined compressive strength relative to the soils when contaminated with Zn alone. The X-ray diffraction and scanning electron microscope analyses reveal the presence of bobierrite (Mg3(PO4)2·8H2O) and K-struvite (MgKPO4·6H2O) as the main products formed in the KMP stabilized uncontaminated soils; the formation of hopeite (Zn3(PO4)2·4H2O), scholzite (CaZn2(PO4)2·2H2O), zinc hydroxide (Zn(OH)2), and fluoropyromorphite (Pb5(PO4)3F) in the soils are the main mechanisms for immobilization of Zn and Pb with the KMP binder. The change in the relative quantities of the formed phosphate-based products, with respect to the Zn concentration and presence of mixed Zn and Pb contaminants, can well explain the measured impact of the Zn concentration levels and presence of both Zn and Pb contaminants on the unconfined compressive strength of the KMP stabilized soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Uranium-lead isotope systematics of Mars inferred from the basaltic shergottite QUE 94201

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

Gaffney, A M; Borg, L E; Connelly, J N

2006-12-22

Uranium-lead ratios (commonly represented as {sup 238}U/{sup 204}Pb = {mu}) calculated for the sources of martian basalts preserve a record of petrogenetic processes that operated during early planetary differentiation and formation of martian geochemical reservoirs. To better define the range of {mu} values represented by the source regions of martian basalts, we completed U-Pb elemental and isotopic analyses on whole rock, mineral and leachate fractions from the martian meteorite Queen Alexandra Range 94201 (QUE 94201). The whole rock and silicate mineral fractions have unradiogenic Pb isotopic compositions that define a narrow range ({sup 206}Pb/{sup 204}Pb = 11.16-11.61). In contrast, themore » Pb isotopic compositions of weak HCl leachates are more variable and radiogenic. The intersection of the QUE 94201 data array with terrestrial Pb in {sup 206}Pb/{sup 204}Pb-{sup 207}Pb/{sup 204}Pb-{sup 208}Pb/{sup 204}Pb compositional space is consistent with varying amounts of terrestrial contamination in these fractions. We calculate that only 1-7% contamination is present in the purified silicate mineral and whole rock fractions, whereas the HCl leachates contain up to 86% terrestrial contamination. Despite the contamination, we are able to use the U-Pb data to determine the initial {sup 206}Pb/{sup 204}Pb of QUE 94201 (11.086 {+-} 0.008) and calculate the {mu} value of the QUE 94201 mantle source to be 1.823 {+-} 0.008. This is the lowest {mu} value calculated for any martian basalt source, and, when compared to the highest values determined for martian basalt sources, indicates that {mu} values in martian source reservoirs vary by at least 100%. The range of source {mu} values further indicates that the {mu} value of bulk silicate Mars is approximately three. The amount of variation in the {mu} values of the mantle sources ({mu} {approx} 2-4) is greater than can be explained by igneous processes involving silicate phases alone. We suggest the possibility that a small amount of sulfide crystallization may generate large extents of U-Pb fractionation during formation of the mantle sources of martian basalts.« less

Lead and cadmium contamination and exposure risk assessment via consumption of vegetables grown in agricultural soils of five-selected regions of Pakistan.

PubMed

Rehman, Zahir Ur; Khan, Sardar; Brusseau, Mark L; Shah, Mohammad Tahir

2017-02-01

Rapid urbanization and industrialization result in serious contamination of soil with toxic metals such as lead (Pb) and cadmium (Cd), which can lead to deleterious health impacts in the exposed population. This study aimed to investigate Pb and Cd contamination in agricultural soils and vegetables in five different agricultural sites in Pakistan. The metal transfer from soil-to-plant, average daily intake of metals, and health risk index (HRI) were also characterized. The Pb concentrations for all soils were below the maximum allowable limits (MAL 350 mg kg -1 ) set by State Environmental Protection Administration of China (SEPA), for soils in China, while Cd concentrations in the soils were exceeded the MAL (61.7-73.7% and 4.39-34.3%) set by SEPA (0.6 mg kg - ), and European Union, (1.5 mg kg -1 ) respectively. The mean Pb concentration in edible parts of vegetables ranged from 1.8 to 11 mg kg -1 . The Pb concentrations for leafy vegetables were higher than the fruiting and pulpy vegetables. The Pb concentrations exceeded the MAL (0.3 mg kg -1 ) for leafy vegetables and the 0.1 mg kg -1 MAL for fruity and rooty/tuber vegetables set by FAO/WHO-CODEX. Likewise, all vegetables except Pisum sativum (0.12 mg kg -1 ) contained Cd concentrations that exceeded the MAL set by SEPA. The HRI values for Pb and Cd were <1 for both adults and children for most of the vegetable species except Luffa acutangula, Solanum lycopersicum, Benincasa hispada, Momordi charantia, Aesculantus malvaceae, Cucumis sativus, Praecitrullus fistulosus, Brassica oleracea, and Colocasia esculanta for children. Based on these results, consumption of these Pb and Cd contaminated vegetables poses a potential health risk to the local consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.

SPECTROSCOPIC SPECIATION AND QUANTIFICATION ON ALTERATIONS OF PB IN PHOSPHATE AMENDED SOILS

EPA Science Inventory

Lead-bearing soils are a source of lead (Pb) contamination at a number of sites across the nation and pose a risk for our most sensitive population, children. The In-place Inactivation and Natural Ecological Restoration Team (IINERT) has demonstrated the feasibility of reducing ...

The removal of lead and nickel from the composted municipal waste and sewage sludge using nanoscale zero-valent iron fixed on quartz.

PubMed

Ghasemzadeh, Parisa; Bostani, Amir

2017-11-01

Reducing the concentration of heavy metals including lead (Pb) and nickel (Ni) in organic contaminants such as municipal wastes and sewage sludge is of health and environmental importance. Nanoscale zero-valent iron (NZVI) particles can effectively remove heavy metals from contaminated aqueous and solid media. It was accordingly hypothesized that it is possible to recycle and detoxify organic waste materials containing heavy metals using NZVI and NZVI fixed on quartz (QNZVI). The objective was to investigate the effects of NZVI type, concentration (2% and 5%) and contact time on the removal of Pb and Ni from raw compost, compost fermented with beet molasses, and leachate using a factorial design. The results indicated the significant reduction of DTPA- Pb and DTPA-Ni concentration, in all the organic compounds treated with NZVI and QNZVI (P= 0.01), compared with control. Increased concentration of NZVI in all treatments, increased the rate of DTPA-Pb and DTPA-Ni (P= 0.01) at 113.1% and 180% for Pb (NZVI at 2% and 5%), and at 16.3% and 23.3% for Ni, irrespective of the NZVI type. The reducing trend of extractable Pb and Ni in all the organic compounds was the same, quick reduction at the beginning, followed by a negligible rate. The highest reduction rates for Pb (at one hour) and Ni (at 672h) were equal to 72.93% and 23.27%, respectively. NZVI at 2% was more efficient than NZVI at 5%. There were not any significant differences between NZVI and QNZVI on the removal of Pb and Ni from the organic contaminants. It is possible to immobilize and reduce the concentration of heavy metals such as Pb and Ni in organic contaminants using NZVI, which is affected by NZVI properties, concentration, and contact time, as well as by organic contaminant type. Copyright © 2017 Elsevier Inc. All rights reserved.

Pollution-induced community tolerance in benthic macroinvertebrates of a mildly lead-contaminated lake.

PubMed

Oguma, Andrew Y; Klerks, Paul L

2017-08-01

Pollution-induced community tolerance (PICT) has been used to demonstrate effects of sediment contamination on microbes and meiofauna. Our study explored the potential to detect PICT in benthic macroinvertebrates of a lake with long-term mild lead (Pb) contamination. We collected macrobenthos from two areas in Caddo Lake, Texas, a control area (CO) with a mean sediment Pb level of 11 μg/g and Goose Prairie (GP) where sediment Pb levels averaged 74 μg/g. Upon return to the laboratory, we exposed macroinvertebrates to a lethal lead concentration and assessed 48-h mortality. Mortality of CO macrobenthos was significantly higher than that of GP macrobenthos, providing evidence that these communities differed in their tolerance to lead. A comparison of macrobenthos community composition between the areas showed that the GP macrobenthos lacked metal-sensitive taxa such as gastropods and amphipods (which were present at CO). Similarly, a higher proportion of the GP benthos belonged to metal-tolerant taxa such as isopods and chironomids. Thus, changes in community composition appeared to be at least partly responsible for differences in community tolerance. Our results showed that a sediment Pb concentration below effect-based sediment quality guidelines had a measurable impact on macrobenthos, thus demonstrating that results from single-species toxicity tests may underestimate impacts on communities. This study also confirms that the PICT approach with macroinvertebrates is a feasible and potentially powerful approach for detecting contaminant impacts.

Arbuscular mycorrhizal fungi-assisted phytoremediation of a lead-contaminated site.

PubMed

Schneider, Jerusa; Bundschuh, Jochen; do Nascimento, Clístenes Williams Araújo

2016-12-01

Knowledge of the behavior of plant species associated with arbuscular mycorrhizal fungi (AMF) and the ability of such plants to grow on metal-contaminated soils is important to phytoremediation. Here, we evaluate the occurrence and diversity of AMF and plant species as well as their interactions in soil contaminated with lead (Pb) from the recycling of automotive batteries. The experimental area was divided into three locations: a non-contaminated native area, a coarse rejects deposition area, and an area receiving particulate material from the chimneys during the Pb melting process. Thirty-nine AMF species from six families and 10 genera were identified. The Acaulospora and Glomus genera exhibited the highest occurrences both in the bulk (10 and 6) and in the rhizosphere soils (9 and 6). All of the herbaceous species presented mycorrhizal colonization. The highest Pb concentrations (mgkg -1 ) in roots and shoots, respectively, were observed in Vetiveria zizanoides (15,433 and 934), Pteris vitata (9343 and 865), Pteridim aquilinun (1433 and 733), and Ricinus communis (1106 and 625). The diversity of AMF seems to be related to the area heterogeneity; the structure communities of AMF are correlated with the soil Pb concentration. We found that plant diversity was significantly correlated with AMF diversity (r=0.645; P>0.05) in areas with high Pb soil concentrations. A better understanding of AMF communities in the presence of Pb stress may shed light on the interactions between fungi and metals taking place in contaminated sites. Such knowledge can aid in developing soil phytoremediation techniques such as phytostabilization. Copyright © 2016 Elsevier B.V. All rights reserved.

Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions

PubMed Central

Mitchell, Rebecca G.; Spliethoff, Henry M.; Ribaudo, Lisa N.; Lopp, Donna M.; Shayler, Hannah A.; Marquez-Bravo, Lydia G.; Lambert, Veronique T.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Stone, Edie B.; McBride, Murray B.

2014-01-01

Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. PMID:24502997

Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions.

PubMed

Mitchell, Rebecca G; Spliethoff, Henry M; Ribaudo, Lisa N; Lopp, Donna M; Shayler, Hannah A; Marquez-Bravo, Lydia G; Lambert, Veronique T; Ferenz, Gretchen S; Russell-Anelli, Jonathan M; Stone, Edie B; McBride, Murray B

2014-04-01

Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. Copyright © 2014 Elsevier Ltd. All rights reserved.

Field demonstration of age dependent increase in lead phytoextraction by Pelargonium cultivar

NASA Astrophysics Data System (ADS)

Shahid, Muhammad; Arshad, Muhammad; Pinelli, Eric; Alric, Alain; Kaemmerer, Michel; Pradere, Philippe; Dumat, Camille

2013-04-01

Unnecessary for living organisms, lead (Pb) is one of the major widespread toxic metals found in the environment with potential danger to human health and to ecosystems (Shahid et al. 2012). Lead is known to induce a broad range of toxic effects to living organism, including those that are morphological, physiological and biochemical in origin (Pourrut et al. 2011). A field study was carried out in the vicinity of Pb recycling plant near Toulouse-France, and contaminated by atmospheric fallouts to evaluate lead extraction and uptake efficiency of hyperaccumulater Attar of Roses Pelargonium cultivar. It was found that Attar of Roses has ability to accumulate (8644 mgPb/kg DW plant) and survive on highly contaminated acidic soil (39250 mg kg-1 of total Pb) without any morpho-phytotoxicity symptoms. Moreover Attar showed increased extraction of lead from bulk soil to rhizosphere through Pb mobilization and ultimately increased uptake by roots and translocation to shoots. The studied contaminated soil could be cleaned up in few years by planting hyperaccumulater Attar of Rose for longer time period. Under optimum fertlization, irrigation and use of natural or synthetic chelates (EDTA, LMOWA, humic substances etc.) along with old Attar of rose plants, time requires for complete remediation of contaminated site can be reduced to practically applicable time period. Moreover, the use of Pelargonium for remediation has several additional practical, esthetical and economic advantages. The extraction of value-added essential oils from harvested biomass could offset the cost of deploying phytoremediation and renders it as a viable approach for remediating highly contaminated soils, on large scale. Keywords: metal uptake, Pelargonium, phytoremediation, cultivar, soil-plant transfer and kinetic. References Pourrut, B., Shahid, M., Dumat, C., Winterton, P., Pinelli, E., 2011a. Lead uptake, toxicity and detoxification in plants. Rev. Environ. Contam. Toxicol. 213, 113-136. Shahid, M., Arshad, M., Kaemmerer, M., Pinelli, E., Probst, A., Baque, D., Pradere, P., Dumat, C., 2012a. Long term field metal extraction by pelargonium: Phytoextraction efficiency in relation with plant maturity. Inter. J. Phytorem. 14, 493-505.

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

USGS Publications Warehouse

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

2009-01-01

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

Predicting potentially plant-available lead in contaminated residential sites.

PubMed

Andra, Syam S; Sarkar, Dibyendu; Saminathan, Sumathi K M; Datta, Rupali

2011-04-01

Lead (Pb)-based paints pose a serious health problem to people living in residential settings constructed prior to 1978. Children are at a greater risk to Pb exposure resulting from hand-to-mouth activity in Pb-contaminated residential soils. For soil Pb, the most environmentally friendly, potentially cheap, and visually unobtrusive in situ technology is phytoremediation. However, the limiting factor in a successful phytoremediation strategy is the availability of Pb for plant uptake. The purpose of this study was to establish a relationship between soil properties and the plant-available/exchangeable Pb fraction in the selected Pb-based paint-contaminated residential sites. We selected 20 such sites from two different locations (San Antonio, Texas and Baltimore, Maryland) with varying soil properties and total soil Pb concentrations ranging between 256 and 4,182 mg kg(-1). Despite higher Pb levels in these soils that exceeds US EPA permissible limit of 400 mg kg(-1), it is known that the plant-available Pb pools are significantly lower because of their sorption to soil components such as organic matter, Fe-Mn oxides, and clays, and their precipitation in the form of carbonates, hydroxides, and phosphates. Principal component analysis and hierarchical clustering showed that the potentially plant-available Pb fraction is controlled by soil pH in the case of acidic Baltimore soils, while soil organic matter plays a major role in alkaline San Antonio soils. Statistical models developed suggest that Pb is likely to be more available for plant uptake in Baltimore soils and a chelant-assisted phytoextraction strategy will be potentially necessary for San Antonio soils in mobilizing Pb from complexed pool to the plant-available pool. A thorough knowledge of site-specific factors is therefore essential in developing a suitable and successful phytoremediation model.

Immobilization of Pb and Cu in polluted soil by superphosphate, multi-walled carbon nanotube, rice straw and its derived biochar.

PubMed

Rizwan, Muhammad Shahid; Imtiaz, Muhammad; Huang, Guoyong; Chhajro, Muhammad Afzal; Liu, Yonghong; Fu, Qingling; Zhu, Jun; Ashraf, Muhammad; Zafar, Mohsin; Bashir, Saqib; Hu, Hongqing

2016-08-01

Lead (Pb) and copper (Cu) contamination in croplands pose severe health hazards and environmental concerns throughout soil-food chain transfer. In the present study, BCR, TCLP, CaCl2, and SBET techniques were employed to evaluate the simultaneous effectiveness of rice straw (RS) and its derived biochar (BC), multiwall carbon nanotube (MWCNT), and single superphosphate (SSP) to immobilize the Pb and Cu in co-contaminated soil. The BCR sequential extraction results suggested that with increasing BC and SSP amount, the acid-soluble fractions decreased while oxidizable and residual proportions of Pb and Cu were increased significantly. Compared to SSP, the application of BC amendment substantially modified partitioning of Cu from easily exchangeable phase to less bioavailable residual bound fraction. The immobilized Pb and Cu were mainly transformed to reducible forms. The TCLP and CaCl2-extracted Pb and Cu were reduced significantly by the addition of BC compared to RS and MWCNT, whereas the bio-accessibility of Pb significantly reduced with RS addition. SSP showed better results for Pb immobilization while marginal for Cu in co-contaminated soil. Overall, the addition of BC offered the best results and could be effective in both Pb and Cu immobilization thereby reducing their mobility and bioavailability in the co-contaminated soil.

IN VITRO SOIL PB SOLUBILITY IN THE PRESENCE OF HYDROXYAPATITE

EPA Science Inventory

The transformation of lead (Pb) in contaminated soils to pyromorphite, by the addition of phosphate minerals, may be an economic in-situ immobilization strategy which also results in a reduction of bioavailable Pb. To test this hypothesis, we conducted two sets of soil-solution e...

Phytoremediation of fuel oil and lead co-contaminated soil by Chromolaena odorata in association with Micrococcus luteus.

PubMed

Jampasri, Kongkeat; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Ounjai, Puey; Kumsopa, Acharaporn

2016-10-02

Phytoremediation is widely promoted as a cost-effective technology for treating heavy metal and total petroleum hydrocarbon (TPH) co-contaminated soil. This study investigated the concurrent removal of TPHs and Pb in co-contaminated soil (27,000 mg kg(-1) TPHs, 780 mg kg(-1) Pb) by growing Siam weed (Chromolaena odorata) in a pot experiment for 90 days. There were four treatments: co-contaminated soil; co-contaminated soil with C. odorata only; co-contaminated soil with C. odorata and Micrococcus luteus inoculum; and co-contaminated soil with M. luteus only. C. odorata survived and grew well in the co-contaminated soil. C. odorata with M. luteus showed the highest Pb accumulation (513.7 mg kg(-1)) and uptake (7.7 mg plant(-1)), and the highest reduction percentage of TPHs (52.2%). The higher TPH degradation in vegetated soils indicated the interaction between the rhizosphere microorganisms and plants. The results suggested that C. odorata together with M. luteus and other rhizosphere microorganisms is a promising candidate for the removal of Pb and TPHs in co-contaminated soils.

The role of sediment ingestion in exposing wood ducks to lead

USGS Publications Warehouse

Beyer, W.N.; Blus, L.J.; Henny, C.J.; Audet, D.

1997-01-01

Waterfowl on lateral lakes of the Coeur d'Alene River and on Lake Coeur d'Alene have been poisoned for many years by lead (Pb) from mining and smelting. In 1992 we undertook a study in the area to determine the importance of sediment ingestion in exposing wood ducks (Aix sponsa) to Pb. Digesta were removed from the intestines of wood ducks collected from contaminated and reference areas. The average Pb concentration in digesta of wood ducks from the contaminated area was 32 ppm dry weight. The sediment content was estimated to average less than 2% of the dry weight of the wood duck diet. Lead concentrations in digesta were closely correlated with concentrations of acid-insoluble ash, Al, Ti and Fe in digesta, and these four variables are associated with sediment. Samples containing low concentrations of these variables also had low concentrations of Pb. These results suggest that most of the Pb in the digesta came from ingested sediment, rather than from plant material in the diet. The importance of ingested sediment as a source of lead was unexpected, because wood ducks are surface feeders on aquatic plants and they rarely dabble beneath the surface or feed on the bottom. However, it appears that sediment ingestion is sometimes the principal route of exposure to environmental contaminants that are not readily taken up by plants and invertebrates, and this route should be considered in risk assessments of waterfowl.

Bioaccessibility Of Lead Sequestered To Corundum and Ferrihydrite In A Simulated Gastrointestinal System

EPA Science Inventory

Lead (Pb) sorption onto oxide surfaces in soils may strongly influence the risk posed from incidental ingestion of Pb-contaminated soil. Lead was sorbed to model oxide minerals of corundum (α-Al₂O₃) and ferrihydrite (Fe₅HO₈•4H₂

Lead in Urban Soils: A Real or Perceived Concern for Urban Agriculture?

PubMed

Brown, Sally L; Chaney, Rufus L; Hettiarachchi, Ganga M

2016-01-01

Urban agriculture is growing in cities across the United States. It has the potential to provide multiple benefits, including increased food security. Concerns about soil contamination in urban areas can be an impediment to urban agriculture. Lead is the most common contaminant in urban areas. In this paper, direct (soil ingestion via outdoor and indoor exposure) and indirect (consumption of food grown in Pb-contaminated soils) exposure pathways are reviewed. It is highly unlikely that urban agriculture will increase incidences of elevated blood Pb for children in urban areas. This is due to the high likelihood that agriculture will improve soils in urban areas, resulting in reduced bioavailability of soil Pb and reduced fugitive dust. Plant uptake of Pb is also typically very low. The exceptions are low-growing leafy crops where soil-splash particle contamination is more likely and expanded hypocotyl root vegetables (e.g., carrot). However, even with higher bioaccumulation factors, it is not clear that the Pb in root vegetables or any other crops will be absorbed after eating. Studies have shown limited absorption of Pb when ingested with food. Best management practices to assure minimal potential for exposure are also common practices in urban gardens. These include the use of residuals-based composts and soil amendments and attention to keeping soil out of homes. This review suggests that benefits associated with urban agriculture far outweigh any risks posed by elevated soil Pb. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Lead uptake increases drought tolerance of wild type and transgenic poplar (Populus tremula x P. alba) overexpressing gsh 1.

PubMed

Samuilov, Sladjana; Lang, Friedericke; Djukic, Matilda; Djunisijevic-Bojovic, Danijela; Rennenberg, Heinz

2016-09-01

Growth and development of plants largely depends on their adaptation ability in a changing climate. This is particularly true on heavy metal contaminated soils, but the interaction of heavy metal stress and climate on plant performance has not been intensively investigated. The aim of the present study was to elucidate if transgenic poplars (Populus tremula x P. alba) with enhanced glutathione content possess an enhanced tolerance to drought and lead (Pb) exposure (single and in combination) and if they are good candidates for phytoremediation of Pb contaminated soil. Lead exposure reduced growth and biomass accumulation only in above-ground tissue of wild type poplar, although most of lead accumulated in the roots. Drought caused a decline of the water content rather than reduced biomass production, while Pb counteracted this decline in the combined exposure. Apparently, metals such as Pb possess a protective function against drought, because they interact with abscisic acid dependent stomatal closure. Lead exposure decreased while drought increased glutathione content in leaves of both plant types. Lead accumulation was higher in the roots of transgenic plants, presumably as a result of chelation by glutathione. Water deprivation enhanced Pb accumulation in the roots, but Pb was subject to leakage out of the roots after re-watering. Transgenic plants showed better adaptation under mild drought plus Pb exposure partially due to improved glutathione synthesis. However, the transgenic plants cannot be considered as a good candidate for phytoremediation of Pb, due to its small translocation to the shoots and its leakage out of the roots upon re-watering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Laser Monitoring Of Phytoextraction Enhancement Of Lead Contaminated Soil Adopting EDTA And EDDS

NASA Astrophysics Data System (ADS)

Hassan, M.; Abdelhamied, M.; Hanafy, A. H.; Fantoni, R.; Harith, M. A.

2011-09-01

Removal of heavy metals (HMs) such as Pb from soil, wastewater, and air is essential for environment and human health. Phytoremediation is a well established technology based on the use of certain green plants for contaminants removal from soil, wastewater as well as air. Scented geranium, Pelargonium zonal, is a flowering plant recently used in HMs removal from contaminated soil. In the present work, EDTA (ethylenediaminetetraacetic acid) and EDDS (S, S-ethylenediaminedisuccinic acid) were used as chemical assistants providing higher Pb availability for extraction by plant roots. Lead was artificially added to the planting media, peatmoss, at different concentrations. Laser induced breakdown spectroscopy (LIBS) was used to follow up Pb relative concentrations in peatmoss as well as plant shoots, at different sampling times during the experiment period. Laser induced chlorophyll fluorescence (LICF), has been also used to evaluate chlorophyll formation and photosynthetic apparatus status in geranium plants. Such measurements were performed on geranium plants grown under various Pb levels, as well as EDTA and EDDS combinations. The combined effect of EDTA and EDDS was found to enhance Pb extraction with time. Good correlation was found between LICF results and chlorophyll (a) (Chl.a) concentrations in plant tissues extracted by chemical analysis.

Adsorbent material based on passion-fruit wastes to remove lead (Pb), chromium (Cr) and copper (Cu) from metal-contaminated waters

NASA Astrophysics Data System (ADS)

Campos-Flores, Gaby; Castillo-Herrera, Alberto; Gurreonero-Fernández, Julio; Obeso-Obando, Aída; Díaz-Silva, Valeria; Vejarano, Ricardo

2018-04-01

The aim of the present work was to evaluate the feasibility of passion-fruit shell (PFS) biomass as adsorbent material to remove heavy metals from contaminated waters. Model mediums were used, which were composed of distilled water and the respective metal: lead (Pb), chromium (Cr) and copper (Cu), with a dose of 10g of dry PFSbiomass per liter of medium. The residual concentration of each metal was determined by Atomic Absorption Spectrophotometry (AAS). A good adsorption capacity was exhibited by this agro industrial waste, achieving removal levels of 96,93 and 82% for Pb, Cr and Cu, respectively. In addition, the results obtained showed an adequate fit to the Freundlich model (R2 > 0.91), on the basis of which, the following values of adsorption capacity (k: 1.7057, 0.6784, 0.3302) and adsorption intensity (n: 0.6869, 2.3474, 1.0499), for Pb, Cr and Cu respectively, were obtained. Our results suggest that Pb, Cr and Cu ions can be removed by more than 80% by using this agro industrial waste, which with a minimum treatment could be used as an adsorbent material in the treatment of metal-contaminated waters.

Simultaneous immobilization of lead and atrazine in contaminated soils using dairy-manure biochar.

PubMed

Cao, Xinde; Ma, Lena; Liang, Yuan; Gao, Bin; Harris, Willie

2011-06-01

Biochar produced from waste biomass is increasingly being recognized as a green, cost-effective amendment for environmental remediation. This work was to determine the ability of biochar to immobilize heavy metal Pb and organic pesticide atrazine in contaminated soils. Biochar prepared from dairy manure was incubated with contaminated soils at rates of 0, 2.5, and 5.0% by weight for 210 d. A commercial activated carbon (AC) was included as a comparison. The AC was effective in immobilizing atrazine, but was ineffective for Pb. However, biochar was effective in immobilizing both atrazine and Pb and the effectiveness was enhanced with increasing incubation time and biochar rates. After 210 d, soils treated with the highest rate of 5.0% biochar showed more than 57% and 66% reduction in Pb and atrazine concentrations in 0.01 M CaCl(2) extraction, respectively. Lead and atrazine concentrations in the toxicity characteristic leaching procedure solutions were reduced by 70-89% and 53-77%, respectively. Uptake of Pb and atrazine by earthworms (Eisenia fetida) was reduced by up to 79% and 73%. Phosphorus originally contained in biochar reacted with soil Pb to form insoluble hydroxypyromorphite Pb(5)(PO(4))(3)(OH), as determined by X-ray diffraction, which was presumably responsible for soil Pb immobilization, whereas atrazine stabilization may result from its adsorption by biochar demonstrated by the significant exponential decrease of extractable atrazine with increasing organic C in biochar (r(2) > 0.97, p < 0.05). The results highlighted the potential of dairy-manure biochar as a unique amendment for immobilization of both heavy metal and organic contaminants in cocontaminated soils.

Isolation of phosphate solubilizing bacteria and their potential for lead immobilization in soil.

PubMed

Park, Jin Hee; Bolan, Nanthi; Megharaj, Mallavarapu; Naidu, Ravi

2011-01-30

Lead (Pb), a highly toxic heavy metal forms stable compounds with phosphate (P). The potential of phosphate solubilizing bacteria (PSB) to immobilize Pb by enhancing solubilization of insoluble P compounds was tested in this research. Eighteen different PSB strains isolated from P amended and Pb contaminated soils were screened for their efficiency in P solubilization. The PSB isolated from P amended soils solubilized 217-479 mg/L of P while the PSB from Pb contaminated soil solubilized 31-293 mg/L of P. Stepwise multiple regression analysis and P solubility kinetics indicated that the major mechanism of P solubilization by PSB is the pH reduction through the release of organic acids. From the isolated bacteria, two PSB were chosen for Pb immobilization and these bacteria were identified as Pantoea sp. and Enterobacter sp., respectively. The PSB significantly increased P solubilization by 25.0% and 49.9% in the case of Pantoea sp., and 63.3% and 88.6% in the case of Enterobacter sp. for 200 and 800 mg/kg of rock phosphate (RP) addition, respectively, thereby enhancing the immobilization of Pb by 8.25-13.7% in the case of Pantoea sp. and 14.7-26.4% in the case of Enterobacter sp. The ability of PSB to solubilize P, promote plant growth, and immobilize Pb can be used for phytostabilization of Pb contaminated soils. Copyright © 2010 Elsevier B.V. All rights reserved.

In-vitro and In-vivo approaches for the measurement of oral bioavailability of lead (Pb) in soil: A critical review

USDA-ARS?s Scientific Manuscript database

Urban soils are commonly contaminated by Pb and some other elements from house paint, automotive emissions, and general urban emissions. Soil Pb near painted houses can exceed 10,000 mg/kg, while commonly ranging from 500 to 1000 mg/kg. Such high soil Pb levels raise concerns about exposure of chi...

Does acute lead (Pb) contamination influence membrane fatty acid composition and freeze tolerance in intertidal blue mussels in arctic Greenland?

PubMed

Thyrring, Jakob; Juhl, Bodil Klein; Holmstrup, Martin; Blicher, Martin E; Sejr, Mikael K

2015-11-01

In their natural habitats, organisms are exposed to multiple stressors. Heavy metal contamination stresses the cell membrane due to increased peroxidation of lipids. Likewise, sub-zero air temperatures potentially reduce membrane functionality in ectothermal animals. We tested if acute lead (Pb) exposure for 7 days would influence survival in intertidal blue mussels (Mytilus edulis) after exposure to realistic sub-zero air temperatures. A full factorial experiment with five tissue Pb concentrations between 0 and 3500 μg Pb/g and six sub-zero temperatures from 0 to -17 °C were used to test the hypothesis that sub-lethal effects of Pb may increase the lethality caused by freezing in blue mussels exposed to temperatures simulating Greenland winter conditions. We found a significant effect of temperature on mortality. However, the short-term exposure to Pb did not result in any effects of Pb, nor did we find interactions between Pb and temperature. We analysed the relative abundance of major phospholipid fatty acids (PLFAs) in the gill tissue, but we found no significant effect of Pb tissue concentration on PLFA composition. Results suggest that Pb accumulation has limited effects on freeze tolerance and does not induce membrane damage in terms of persistent lipid peroxidation.

Lead and Arsenic Uptake by Leafy Vegetables Grown on Contaminated Soils: Effects of Mineral and Organic Amendments

PubMed Central

McBride, Murray B.; Simon, Tobi; Tam, Geoffrey; Wharton, Sarah

2015-01-01

To assess strategies for mitigating Pb and As transfer into leafy vegetables from contaminated garden soils, we conducted greenhouse experiments using two field-contaminated soils amended with materials expected to reduce metal phytoavailability. Lettuce and mustard greens grown on these soils were analysed by ICP-MS, showing that some Pb and As transfer into the vegetables occurred from both soils tested, but plant Pb concentrations were highly variable among treatment replicates. Soil-to-plant transfer was more efficient for As than for Pb. Contamination of the leaves by soil particles probably accounted for most of the vegetable Pb, since plant Pb concentrations were correlated to plant tissue concentrations of the immobile soil elements Al and Fe. This correlation was not observed for vegetable As concentrations, evidence that most of the soil-to-plant transfer for this toxic metal occurred by root uptake and translocation into the above-ground tissues. A follow-up greenhouse experiment with lettuce on one of the two contaminated soils revealed a lower and less variable foliar Pb concentration than observed in the first experiment, with evidence of less soil particle contamination of the crop. This reduced transfer of Pb to the crop appeared to be a physical effect attributable to the greater biomass causing reduced overall exposure of the above-ground tissues to the soil surface. Attempts to reduce soil Pb and As solubility and plant uptake by amendment at practical rates with stabilizing materials including composts, peat, Ca phosphate, gypsum and Fe oxide, were generally unsuccessful. Only Fe oxide reduced soluble As in the soil, but this effect did not persist. Phosphate amendment rapidly increased soil As solubility but had no measurable effect on either soil Pb solubility or concentrations of Pb or As in the leafy vegetables. The ineffectiveness of these amendments in reducing Pb transfer into leafy vegetables is attributed in this study to the low initial Pb solubility of the studied soils and the fact that the primary mechanism of Pb transfer is physical contamination. PMID:26884640

The effects of lead sources on oral bioaccessibility in soil and implications for contaminated land risk management.

PubMed

Palmer, Sherry; McIlwaine, Rebekka; Ofterdinger, Ulrich; Cox, Siobhan F; McKinley, Jennifer M; Doherty, Rory; Wragg, Joanna; Cave, Mark

2015-03-01

Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg(-1)) and mineralisation (199.8 mg kg(-1)) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg(-1)) and granite (36.0 mg kg(-1)) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land. Copyright © 2015 Elsevier Ltd. All rights reserved.

Iodide-assisted total lead measurement and determination of different lead fractions in drinking water samples.

PubMed

Zhang, Yuanyuan; Ng, Ding-Quan; Lin, Yi-Pin

2012-07-01

Lead and its compounds are toxic and can harm human health, especially the intelligence development in children. Accurate measurement of total lead present in drinking water is crucial in determining the extent of lead contamination and human exposure due to drinking water consumption. The USEPA method for total lead measurement (no. 200.8) is often used to analyze lead levels in drinking water. However, in the presence of high concentration of the tetravalent lead corrosion product PbO(2), the USEPA method was not able to fully recover particulate lead due to incomplete dissolution of PbO(2) particles during strong acid digestion. In this study, a new procedure that integrates membrane separation, iodometric PbO(2) measurement, strong acid digestion and ICP-MS measurement was proposed and evaluated for accurate total lead measurement and quantification of different lead fractions including soluble Pb(2+), particulate Pb(II) carbonate and PbO(2) in drinking water samples. The proposed procedure was evaluated using drinking water reconstituted with spiked Pb(2+), spiked particulate Pb(II) carbonate and in situ formed or spiked PbO(2). Recovery tests showed that the proposed procedure and the USEPA method can achieve 93-112% and 86-103% recoveries respectively for samples containing low PbO(2) concentrations (0.018-0.076 mg Pb per L). For samples containing higher concentrations of PbO(2) (0.089-1.316 mg Pb per L), the USEPA method failed to meet the recovery requirement for total lead (85-115%) while the proposed method can achieve satisfactory recoveries (91-111%) and differentiate the soluble Pb(2+), particulate Pb(II) carbonate and PbO(2).

Enhanced accumulation of copper and lead in amaranth (Amaranthus paniculatus), Indian mustard (Brassica juncea) and sunflower (Helianthus annuus).

PubMed

Rahman, Motior M; Azirun, Sofian M; Boyce, Amru N

2013-01-01

Soil contamination by copper (Cu) and lead (Pb) is a widespread environmental problem. For phytoextraction to be successful and viable in environmental remediation, strategies that can improve plant uptake must be identified. In the present study we investigated the use of nitrogen (N) fertilizer as an efficient way to enhance accumulation of Cu and Pb from contaminated industrial soils into amaranth, Indian mustard and sunflower. Plants were grown in a greenhouse and fertilized with N fertilizer at rates of 0, 190 and 380 mg kg⁻¹ soil. Shoots, roots and total accumulation of Cu and Pb, transfer factor (TF), translocation index were assessed to evaluate the transport and translocation ability of tested plants. Addition of N fertilizer acidified the industrial soil and caused the pH to decrease to 5.5 from an initial pH of 6.9. Industrial soil amended with N fertilizer resulted in the highest accumulation of Pb and Cu (for Pb 10.1-15.5 mg kg⁻¹, for Cu 11.6-16.8 mg kg⁻¹) in the shoots, which was two to four folds higher relative to the concentration in roots in all the three plants used. Sunflower removed significantly higher Pb (50-54%) and Cu (34-38%) followed by amaranth and Indian mustard from industrial soils with the application of N fertilizer. The TF was <1 while the shoot and root concentration (SC/RC) ratios of Pb and Cu were between 1.3-4.3 and 1.8-3.8, respectively, regardless of plant species. Sunflower is the best plant species to carry out phytoextraction of Pb and Cu. In contrast, Pb and Cu removal by Indian mustard and amaranth shows great potential as quick and short duration vegetable crops. The results suggest that the application of N fertilizer in contaminated industrial soil is an effective amendment for the phytoextraction of Pb and Cu from contaminated industrial soils.

Analysis of Pollution Hazard Intensity: A Spatial Epidemiology Case Study of Soil Pb Contamination

PubMed Central

Ha, Hoehun; Rogerson, Peter A.; Olson, James R.; Han, Daikwon; Bian, Ling; Shao, Wanyun

2016-01-01

Heavy industrialization has resulted in the contamination of soil by metals from anthropogenic sources in Anniston, Alabama. This situation calls for increased public awareness of the soil contamination issue and better knowledge of the main factors contributing to the potential sources contaminating residential soil. The purpose of this spatial epidemiology research is to describe the effects of physical factors on the concentration of lead (Pb) in soil in Anniston AL, and to determine the socioeconomic and demographic characteristics of those residing in areas with higher soil contamination. Spatial regression models are used to account for spatial dependencies using these explanatory variables. After accounting for covariates and multicollinearity, results of the analysis indicate that lead concentration in soils varies markedly in the vicinity of a specific foundry (Foundry A), and that proximity to railroads explained a significant amount of spatial variation in soil lead concentration. Moreover, elevated soil lead levels were identified as a concern in industrial sites, neighborhoods with a high density of old housing, a high percentage of African American population, and a low percent of occupied housing units. The use of spatial modelling allows for better identification of significant factors that are correlated with soil lead concentrations. PMID:27649221

Analysis of Pollution Hazard Intensity: A Spatial Epidemiology Case Study of Soil Pb Contamination.

PubMed

Ha, Hoehun; Rogerson, Peter A; Olson, James R; Han, Daikwon; Bian, Ling; Shao, Wanyun

2016-09-14

Heavy industrialization has resulted in the contamination of soil by metals from anthropogenic sources in Anniston, Alabama. This situation calls for increased public awareness of the soil contamination issue and better knowledge of the main factors contributing to the potential sources contaminating residential soil. The purpose of this spatial epidemiology research is to describe the effects of physical factors on the concentration of lead (Pb) in soil in Anniston AL, and to determine the socioeconomic and demographic characteristics of those residing in areas with higher soil contamination. Spatial regression models are used to account for spatial dependencies using these explanatory variables. After accounting for covariates and multicollinearity, results of the analysis indicate that lead concentration in soils varies markedly in the vicinity of a specific foundry (Foundry A), and that proximity to railroads explained a significant amount of spatial variation in soil lead concentration. Moreover, elevated soil lead levels were identified as a concern in industrial sites, neighborhoods with a high density of old housing, a high percentage of African American population, and a low percent of occupied housing units. The use of spatial modelling allows for better identification of significant factors that are correlated with soil lead concentrations.

Trend and concentrations of legacy lead (Pb) in highway runoff.

PubMed

Kayhanian, Masoud

2012-01-01

This study presents the results of lead (Pb) concentrations from both highway runoff and contaminated soil along 32 and 23 highway sites, respectively. In general, the Pb concentration on topsoil (0-15 cm) along highways was much higher than the Pb concentration in subsurface soil (15-60 cm). The Pb deposited on soil appears to be anthropogenic and a strong correlation was found between the Pb concentration in surface soil and highway runoff in urban areas. The concentration of Pb measured during 1980s from highways runoff throughout the world was up to 11 times higher than the measured values in mid 1990 s and 2000s. The current Pb deposited on soil near highways appears to be a mixture of paint, tire weight balance and old leaded gasoline combustion. Overall, the Pb phase-out regulation reduced the Pb deposits in the environment and consequently lowered Pb loading into receiving waters. Copyright © 2011 Elsevier Ltd. All rights reserved.

EDTA-assisted leaching of Pb and Cd from contaminated soil.

PubMed

Qiao, Jiangbo; Sun, Huimin; Luo, Xiuhua; Zhang, Wang; Mathews, Shiny; Yin, Xianqiang

2017-01-01

Lead (Pb) and cadmium (Cd) contamination of soil and its harmful effects on human and environmental health have been one concern. In this study, batch and column leaching experiments were conducted to investigate the effects of two EDTA-assisted leaching methods, continuous and intermittent (dry-wet alternate), on the removal of Pb and Cd from contaminated soil. Total content and fractions of Pb and Cd at every 1 cm soil column depth were analyzed before and after the leaching. The results indicated that continuous leaching removed 75.43% of Pb (19.370 mg) and 53.21% of Cd (6.168 mg) and intermittent leaching removed 78.08% of Pb (20.051 mg) and 57.37% of Cd (6.650 mg), which showed intermittent leaching removed more Pb and Cd, but didn't differ significantly (P > 0.05) compared to the continuous leaching. In both leaching methods, total Pb and Cd content in all soil depths reduced after leaching. The two leaching methods made no significant differences in Pb and Cd distributions at different depths of the soil column. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lead in mule deer forage in Rocky Mountain National Park, Colorado

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

Harrison, P.D.; Dyer, M.I.

1984-01-01

Mule deer (Odocoileus hemionus) forage collected from roadsides in Rocky Mountain National Park, Colorado, contained lead (Pb) concentrations ranging from 0.8 to >50 ..mu..g/g. Concentrations were inversely correlated with distance from the roadway. Equations developed to estimate deer absorption of Pb from contaminated roadside vegetation indicate that deer in some age-classes need only to consume 1.4% of their daily intake of forage from roadsides before consuming excessive amounts of Pb.

IN SITU LEAD IMMOBILIZATION BY APATITE

EPA Science Inventory

Lead contamination is of environmental concern due to its effect on human health. The purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. Hydroxyapatite [Ca₁₀(PO₄)₆(O...

Lead-resistant Providencia alcalifaciens strain 2EA bioprecipitates Pb+2 as lead phosphate.

PubMed

Naik, M M; Khanolkar, D; Dubey, S K

2013-02-01

A lead-resistant bacteria isolated from soil contaminated with car battery waste were identified as Providencia alcalifaciens based on biochemical characteristics, FAME profile and 16S rRNA sequencing and designated as strain 2EA. It resists lead nitrate up to 0·0014 mol l(-1) by precipitating soluble lead as insoluble light brown solid. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometric analysis (SEM-EDX) and X-ray diffraction spectroscopy (XRD) revealed extracellular light brown precipitate as lead orthophosphate mineral, that is, Pb(9) (PO(4))(6) catalysed by phosphatase enzyme. This lead-resistant bacterial strain also demonstrated tolerance to high levels of cadmium and mercury along with multiple antibiotic resistance. Providencia alcalifaciens strain 2EA could be used for bioremediation of lead-contaminated environmental sites, as it can efficiently precipitate lead as lead phosphate. © 2012 The Society for Applied Microbiology.

Phosphorus Amendment Efficacy for In Situ Remediation of Soil Lead Depends on the Bioaccessible Method

EPA Science Inventory

A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccesible Pb in P-treated soils. Two Pb-contaminated soils...

Influence of Nano-Hydroxyapatite on the Metal Bioavailability, Plant Metal Accumulation and Root Exudates of Ryegrass for Phytoremediation in Lead-Polluted Soil

PubMed Central

Ding, Ling; Li, Jianbing; Liu, Wei; Zuo, Qingqing; Liang, Shu-xuan

2017-01-01

Lead is recognized as one of the most widespread toxic metal contaminants and pervasive environmental health concerns in the environment. In this paper, the effects of nano-hydroxyapatite (NHAP) on remediation in artificially Pb-contaminated soils and ryegrass were studied in a pot experiment. The addition of NHAP decreased the water- and acid-soluble, exchangeable, and reducible fractions of Pb, extracted using the Community Bureau of Reference (BCR) method, whilst greatly increasing the residual fraction of Pb. Oxidizable Pb was increased slightly. No significant increase in soil pH was caused by the application of NHAP. Compared to conditions without NHAP, the addition of NHAP decreased the Pb content in ryegrass shoots and roots by 13.19–20.3% and 2.86–21.1%, respectively. Therefore, the application of NHAP reduced the mobility and bioavailability of Pb in the soil. In addition, the application of NHAP improved the fresh weight of shoots and roots, and promoted the growth of ryegrass. NHAP played a positive role in stimulating ryegrass to secrete tartaric acid. PMID:28509844

Effects of alkaline and bioorganic amendments on cadmium, lead, zinc, and nutrient accumulation in brown rice and grain yield in acidic paddy fields contaminated with a mixture of heavy metals.

PubMed

He, Huaidong; Tam, Nora F Y; Yao, Aijun; Qiu, Rongliang; Li, Wai Chin; Ye, Zhihong

2016-12-01

Paddy soils and rice (Oryza sativa L.) contaminated by mixed heavy metals have given rise to great concern. Field experiments were conducted over two cultivation seasons to study the effects of steel slag (SS), fly ash (FA), limestone (LS), bioorganic fertilizer (BF), and the combination of SS and BF (SSBF) on rice grain yield, Cd, Pb, and Zn and nutrient accumulation in brown rice, bioavailability of Cd, Pb, and Zn in soil as well as soil properties (pH and catalase), at two acidic paddy fields contaminated with mixed heavy metals (Cd, Pb, and Zn). Compared to the controls, SS, LS, and SSBF at both low and high additions significantly elevated soil pH over both cultivation seasons. The high treatments of SS and SSBF markedly increased grain yields, the accumulation of P and Ca in brown rice and soil catalase activities in the first cultivation season. The most striking result was from SS application (4.0 t ha -1 ) that consistently and significantly reduced the soil bioavailability of Cd, Pb, and Zn by 38.5-91.2 % and the concentrations of Cd and Pb in brown rice by 20.9-50.9 % in the two soils over both cultivation seasons. LS addition (4.0 t ha -1 ) also markedly reduced the bioavailable Cd, Pb, and Zn in soil and the Cd concentrations in brown rice. BF remobilized soil Cd and Pb leading to more accumulation of these metals in brown rice. The results showed that steel slag was most effective in the remediation of acidic paddy soils contaminated with mixed heavy metals.

A three-year experiment confirms continuous immobilization of cadmium and lead in contaminated paddy field with biochar amendment.

PubMed

Bian, Rongjun; Joseph, Stephen; Cui, Liqiang; Pan, Genxing; Li, Lianqing; Liu, Xiaoyu; Zhang, Afeng; Rutlidge, Helen; Wong, Singwei; Chia, Chee; Marjo, Chris; Gong, Bin; Munroe, Paul; Donne, Scott

2014-05-15

Heavy metal contamination in croplands has been a serious concern because of its high health risk through soil-food chain transfer. A field experiment was conducted in 2010-2012 in a contaminated rice paddy in southern China to determine if bioavailability of soil Cd and Pb could be reduced while grain yield was sustained over 3 years after a single soil amendment of wheat straw biochar. Contaminated biochar particles were separated from the biochar amended soil and microscopically analyzed to help determine where, and how, metals were immobilized with biochar. Biochar soil amendment (BSA) consistently and significantly increased soil pH, total organic carbon and decreased soil extractable Cd and Pb over the 3 year period. While rice plant tissues' Cd content was significantly reduced, depending on biochar application rate, reduction in plant Pb concentration was found only in root tissue. Analysis of the fresh and contaminated biochar particles indicated that Cd and Pb had probably been bonded with the mineral phases of Al, Fe and P on and around and inside the contaminated biochar particle. Immobilization of the Pb and Cd also occurred to cation exchange on the porous carbon structure. Copyright © 2014 Elsevier B.V. All rights reserved.

Asian anthropogenic lead contamination in the North Pacific Ocean as evidenced by stable lead isotopic compositions

NASA Astrophysics Data System (ADS)

Zurbrick, Cheryl M.

This dissertation work determined the changing scope of lead (Pb) contamination in the North Pacific Ocean since the phase-out of leaded gasoline in most of the world. Chapters 1 and 2 consisted of validating our method for determining Pb concentrations and isotopic compositions in seawater. Chapter 3 established a baseline of Pb isotopic compositions (PbICs) in the western and central North Pacific in 2002. This was an ideal time to establish such a baseline because China had recently (mid-2000) ceased their use of leaded gasoline and simultaneously began consuming increasingly large amounts of coal, known to have relatively high Pb concentrations. We found subsurface waters were contaminated with Asian industrial Pb, predominantly Chinese coal emissions. In contrast, the abyssal waters were a mix of Asian industrial Pb and background (i.e., natural) Pb. Chapter 4 revisited the western and central North Pacific in 2009 -- 2011 to determine what, if any, changes had occurred in this short time period. We found that Pb in subsurface and abyssal waters of the western North Pacific were similar to Chinese aerosols. Such a large change in the PbICs of abyssal water in 9 years was unanticipated and attributed to the relatively large flux of particle-bound Pb from the euphotic zone to the deep ocean, which was in isotopic equilibrium with the reservoir of dissolved Pb. In contrast, the central North Pacific abyssal water PbICs were similar to values previously reported because of the relatively lower particulate export. Based on comparisons to baseline PbIC data, we determined that abyssal waters in the western and central North Pacific would be isotopically indistinguishable from surface waters in the next three decades. Sources of Pb to coastal California waters were reevaluated in Chapter 5. Prior studies had found that surface waters of the California Current System (CCS) were isotopically consistent with both Asian industrial Pb and US leaded gasoline, still in use at that point in time. In 2010 and 2011, we found that surface and subsurface waters of the CCS were isotopically similar to Asian industrial emissions. However, remobilized US gasoline Pb from sediments in the San Francisco Bay, California, were accumulating in the "mud belt" on the continental shelf and changing the isotopic composition of overlying waters. During periods of intense upwelling, this historic Pb was brought to the surface of the water. However, the much larger quantity of Pb from Asian industrial emissions made the isotopic composition of Pb from historic US gasoline unidentifiable in off-shore waters. A secondary research focus of this dissertation was to improve my own teaching abilities. Chapter 6 explored the intersection of system thinking and aquatic toxicology in undergraduate education. Among a wealth of information, I found that group concept mapping was no more useful to student learning than the same activity done individually. This was due to poor implementation of team learning strategies by me and inadequate time for students to adjust to non-traditional instruction methodologies.

Contamination of houses by workers occupationally exposed in a lead-zinc-copper mine and impact on blood lead concentrations in the families.

PubMed Central

Chiaradia, M; Gulson, B L; MacDonald, K

1997-01-01

OBJECTIVE: To evaluate the pathway of leaded dust from a lead-zinc-copper mine to houses of employees, and the impact on blood lead concentrations (PbB) of children. METHODS: High precision lead isotope and lead concentration data were obtained on venous blood and environmental samples (vacuum cleaner dust, interior dustfall accumulation, water, paint) for eight children of six employees (and the employees) from a lead-zinc-copper mine. These data were compared with results for 11 children from occupationally unexposed control families living in the same city. RESULTS: The median (range) concentrations of lead in vacuum cleaner dust was 470 (21-1300) ppm. In the houses of the mine employees, vacuum cleaner dust contained varying higher proportions of mine lead than did airborne particulate matter measured as dustfall accumulated over a three month period. The median (range) concentrations of lead in soil were 30 (5-407) ppm and these showed no evidence of any mine lead. Lead in blood of the mine employees varied from 7 to 25 micrograms/dl and was generally dominated by mine lead (> 60%). The mean (SD) PbB in the children of the mine employees was 5.7 (1.7) micrograms/dl compared with 4.1 (1.4) micrograms/dl for the control children (P = 0.02). The PbB of all children was always < 10 micrograms/dl, the Australian National Health and Medical Research Council goal for all Australians. Some of the control children had higher PbB than the children of mine employees, probably from exposure to leaded paint as six of the eight houses of the control children were > 50 years old. In five of the eight children of mine employees > 20% of PbB was from the lead mine. However, in the other three cases of children of mine employees, their PbB was from sources other than mine lead (paint, petrol, background sources). CONCLUSIONS: Houses of employees from a lead mine can be contaminated by mine lead even if they are not situated in the same place as the mine. Delineation of the mine to house pathway indicates that lead is probably transported into the houses on the clothes, shoes, hair, skin, and in some cases, motor vehicles of the workers. In one case, dust shaken from clothes of a mine employee contained 3000 ppm lead which was 100% mine lead. The variable contamination of the houses was not expected given the precautions taken by mine employees to minimise transportation of lead into their houses. Although five out of the eight children of mine employees had > 20% mine lead in their blood, in no case did the PbB of a child exceed the Australian National Health and Medical Research Council goal of 10 micrograms/dl. In fact, some children in the control families had higher PbB than children of mine employees. In two cases, this was attributed to a pica habit for paint. The PbB in the children of mine employees and controls was independent of the source of lead. The low PbB in the children of mine employees may reflect the relatively low solubility (bioavailability) of the mine dust in 0.1 M hydrochloric acid (< 40 %), behaviour--for example, limited mouthing activity--or diet. PMID:9072019

Combining lead isotopes and cluster analysis to distinguish the Guarani and Serra Geral Aquifer Systems and contaminated waters in a highly industrialized area in Southern Brazil.

PubMed

Kuhn, Isadora Aumond; Roisenberg, Ari

2017-10-01

The Rio dos Sinos Watershed area is located at the Middle-West region of the Rio Grande do Sul State, Southern Brazil, along thirty two municipalities and affecting 1.5 million inhabitants and many important industrial centers. Three main aquifers are recognized in the study area: the unconfined-fractured Serra Geral Aquifer System, the porous Guarani Aquifer System, and the Permian Aquitard. This study aims to understand groundwater, surface water and human activity interactions in the Rio dos Sinos Watershed, evaluating the application of stable lead isotopic ratios analyzed for this propose. Thirty six groundwater samples, 8 surface water samples and 5 liquid effluents of tanneries and landfills samples were measured using a Thermal Ionization Mass Spectrometer Thermo-Finnigan and a Neptune Multi-Collector Inductively Coupled Plasma Mass Spectrometer. Groundwater isotopic ratios have a wider range compared to the surface water, with less radiogenic averages 208 Pb/ 204 Pb = 38.1837 vs 38.4050 (standard deviation = 0.2921 vs 0.1343) and 206 Pb/ 204 Pb = 18.2947 vs 18.4766 (standard deviation = 0.2215 vs 0.1059), respectively. Industrial liquid effluents (tanneries and industrial landfill) have averages 208 Pb/ 204 Pb = 38.1956 and 206 Pb/ 204 Pb = 18.3169, distinct from effluent samples of domestic sanitary landfill (averages 208 Pb/ 204 Pb = 38.2353 and 206 Pb/ 204 Pb = 18.6607). Hierarchical cluster analysis led to distinguish six groups of groundwater, representing the three aquifers that occur in the area, two clusters suggesting groundwater mixtures and one demonstrating a highly contaminated groundwater. By analyzing the cluster results and wells' stratigraphic profiles it was possible to distinguish the different aquifers in the area. The Serra Geral Aquifer System has 206 Pb/ 204 Pb ratios between 18.4718 and 18.7089; 207 Pb/ 204 Pb between 15.6692 and 15.6777; 208 Pb/ 204 Pb between 38.6826 and 38.7616; 207 Pb/ 206 Pb between 0.8372 and 0.8623; 208 Pb/ 206 Pb between 2.0671 and 2.0964 and the Guarani Aquifer System has a wider range ( 208 Pb/ 204 Pb ranged from 37.9393 to 38.1279 and 206 Pb/ 204 Pb ranged from 18.0892 to 18.3217). Water mixing of these two aquifer systems is reflected by transitional results. The results confirm that the hierarchical cluster analysis of lead isotopes is a useful tool to discriminate different aquifer conditions, reflecting mostly the influence of the natural lead isotopic composition of the aquifers instead of the anthropogenic activities (urban and industrial), except when the groundwater is highly contaminated by human activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

U-Pb systematics in iron meteorites - Uniformity of primordial lead

NASA Astrophysics Data System (ADS)

Gopel, C.; Manhes, G.; Allegre, C. J.

1985-08-01

Pb isotopic compositions and U-Pb abundances were determined in the metal phase of six iron meteorites: Canyon Diablo IA, Toluca IA, Odessa IA, Youndegin IA, Deport IA, and Mundrabilla An. Prior to complete dissolution, samples were subjected to a series of leachings and partial dissolutions. Isotopic compositions and abundances of the etched Pb indicate a contamination by terrestrial Pb which is attributable to previous cutting of the meteorite. Pb isotopic compositions measured in the decontaminated samples are identical within 0.2 percent and essentially confirm the primordial Pb value defined by Tatsumoto et al. (1973). These data invalidate more radiogenic Pb isotopic compositions published for iron meteorites, which are the result of terrestrial Pb contamination introduced mainly by analytical procedure. The results of this study support the idea of a solar nebula which was isotopically homogeneous for Pb 4.55 Ga ago. The new upper limit for U-abundance in iron meteorites, 0.001 ppb, is in agreement with its expected thermodynamic solubility in the metal phase.

Identification of Scirpus triqueter root exudates and the effects of organic acids on desorption and bioavailability of pyrene and lead in co-contaminated wetland soils.

PubMed

Hou, Yunyun; Liu, Xiaoyan; Zhang, Xinying; Chen, Xiao; Tao, Kaiyun; Chen, Xueping; Liang, Xia; He, Chiquan

2015-11-01

Root exudates (REs) of Scirpus triqueter were extracted from the rhizosphere soil in this study. The components in the REs were identified by GC-MS. Many organic acids, such as hexadecanoic acid, pentadecanoic acid, vanillic acid, octadecanoic acid, citric acid, succinic acid, glutaric acid, and so on, were found. Batch simulated experiments were conducted to evaluate the impacts of different organic acids, such as citric acid, artificial root exudates (ARE), succinic acid, and glutaric acid in REs of S. triqueter on desorption of pyrene (PYR) and lead (Pb) in co-contaminated wetland soils. The desorption amount of PYR and Pb increased with the rise in concentrations of organic acids in the range of 0-50 g·L(-1), within shaking time of 2-24 h. The desorption effects of PYR and Pb in soils with various organic acids treatments decreased in the following order: citric acid > ARE > succinic acid > glutaric acid. The desorption rate of PYR and Pb was higher in co-contaminated soil than in single pollution soil. The impacts of organic acids in REs of S. triqueter on bioavailability of PYR and Pb suggested that organic acids enhanced the bioavailability of PYR and Pb in wetland soil, and the bioavailability effects of organic acids generally followed the same order as that of desorption effects.

AMENDING SOILS WITH PHOSPHATE AS MEANS TO ...

EPA Pesticide Factsheets

Ingested soil and surface dust may be important contributors to elevated blood lead (Pb) levels in children exposed to Pb contaminated environments. Mitigation strategies have typically focused on excavation and removal of the contaminated soil. However, this is not always feasible for addressing widely disseminated contamination in populated areas often encountered in urban environments. The rationale for amending soils with phosphate is that phosphate will promote formation of highly insoluble Pb species (e.g., pyromorphite minerals) in soil, which will remain insoluble after ingestion and, therefore, inaccessible to absorption mechanisms in the gastrointestinal tract (GIT). Amending soil with phosphate might potentially be used in combination with other methods that reduce contact with or migration of contaminated soils, such as covering the soil with a green cap such as sod, clean soil with mulch, raised garden beds, or gravel. These remediation strategies may be less expensive and far less disruptive than excavation and removal of soil. This review evaluates evidence for efficacy of phosphate amendments for decreasing soil Pb bioavailability. Evidence is reviewed for (1) physical and chemical interactions of Pb and phosphate that would be expected to influence bioavailability, (2) effects of phosphate amendments on soil Pb bioaccessibility (i.e., predicted solubility of Pb in the GIT), and (3) results of bioavailability bioassays of amended soils con

Assessing Metal Mobilization from Industrially Lead ...

EPA Pesticide Factsheets

A series of leaching and partitioning tests (Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), Controlled Acidity Leaching Protocol (CALP), Acid Neutralization Capacity (ANC), and sequential extraction) were applied to three different soils to study potential mobility of metals into groundwater. Two of these soils were lead (Pb)-contaminated soils (Hotspot 1 and Hotspot 2) collected from an urban site associated with lead smelting and other industrial operations. The third sample (Stockpile) was soil affected by previous contamination in the area, removed from residential properties, stockpiled, and selected to be used as fill material in the studied site. The TCLP and CALP showed that Pb could be released from both hotspots, but were not released in the acidic rainfall extraction fluid of the SPLP. The sequential extraction showed that Pb in the hotspot soils was associated with the carbonate fraction, while As was associated with the Fe and Mn oxides. The stockpile released traces of Pb or As in the TCLP and CALP, but the ANC only released Pb under acidic conditions and the SPLP did not release Pb or As. Overall, the projected repository with Stockpile would not pose imminent danger to groundwater because, under the expected environmental conditions, Pb and As tend to remain in the solid phase. The objectives of this study were to determine if the stockpiled soil was suitable for the intended fill purpo

Historical record of lead accumulation and source in the tidal flat of Haizhou Bay, Yellow Sea: Insights from lead isotopes.

PubMed

Zhang, Rui; Guan, Minglei; Shu, Yujie; Shen, Liya; Chen, Xixi; Zhang, Fan; Li, Tiegang

2016-05-15

In order to investigate the historical records of lead contamination and source in coastal region of Haizhou Bay, Yellow Sea, a sediment core was collected from tidal flat, dated by (210)Pb and (137)Cs. Lead and its stable isotopic ratios were determined. The profiles of enrichment factor (EF) and Pb isotope ratios showed increasing trend upward throughout the core, correlating closely with the experience of a rapid economic and industrial development of the catchment. According to Pb isotopic ratios, coal combustion emission mainly contributed to the Pb burden in sediments. Based on end-member model, coal combustion emission dominated anthropogenic Pb sources in recent decades contributing from 48% to 67% in sediment. And the contribution of leaded gasoline was lower than 20%. A stable increase of coal combustion source was found in sediment core, while the contribution of leaded gasoline had declined recently, with the phase-out of leaded gasoline in China. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potential value of phosphate compounds in enhancing immobilization and reducing bioavailability of mixed heavy metal contaminants in shooting range soil.

PubMed

Seshadri, B; Bolan, N S; Choppala, G; Kunhikrishnan, A; Sanderson, P; Wang, H; Currie, L D; Tsang, Daniel C W; Ok, Y S; Kim, G

2017-10-01

Shooting range soils contain mixed heavy metal contaminants including lead (Pb), cadmium (Cd), and zinc (Zn). Phosphate (P) compounds have been used to immobilize these metals, particularly Pb, thereby reducing their bioavailability. However, research on immobilization of Pb's co-contaminants showed the relative importance of soluble and insoluble P compounds, which is critical in evaluating the overall success of in situ stabilization practice in the sustainable remediation of mixed heavy metal contaminated soils. Soluble synthetic P fertilizer (diammonium phosphate; DAP) and reactive (Sechura; SPR) and unreactive (Christmas Island; CPR) natural phosphate rocks (PR) were tested for Cd, Pb and Zn immobilization and later their mobility and bioavailability in a shooting range soil. The addition of P compounds resulted in the immobilization of Cd, Pb and Zn by 1.56-76.2%, 3.21-83.56%, and 2.31-74.6%, respectively. The reactive SPR significantly reduced Cd, Pb and Zn leaching while soluble DAP increased their leachate concentrations. The SPR reduced the bioaccumulation of Cd, Pb and Zn in earthworms by 7.13-23.4% and 14.3-54.6% in comparison with earthworms in the DAP and control treatment, respectively. Bioaccessible Cd, Pb and Zn concentrations as determined using a simplified bioaccessibility extraction test showed higher long-term stability of P-immobilized Pb and Zn than Cd. The differential effect of P-induced immobilization between P compounds and metals is due to the variation in the solubility characteristics of P compounds and nature of metal phosphate compounds formed. Therefore, Pb and Zn immobilization by P compounds is an effective long-term remediation strategy for mixed heavy metal contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potential of chitosan (chemically-modified chitin) for extraction of lead-arsenate contaminated soils

USDA-ARS?s Scientific Manuscript database

Arsenic (As), phosphorous (P), and lead (Pb) contamination in soils represents a health risk to humans and the environment. Chitosan (poly-N-acetyl glucosamine) is a non-toxic and inexpensive food industry byproduct derived from chitin that has been used as an adsorbent of heavy metals. The object...

Historic and Industrial Lead within the Northwest Pacific Ocean Evidenced by Lead Isotopes in Seawater.

PubMed

Zurbrick, Cheryl M; Gallon, Céline; Flegal, A Russell

2017-02-07

We report the continued lead (Pb) contamination of the Northwest Pacific Ocean in 2002 and present the first comprehensive Pb isotope data set for that region. In the upper ocean, a Pb concentration maxima (64-113 pmol kg -1 ) extended throughout the entire North Pacific Subtropical Gyre (NPSG). We determined most of the Pb in this feature was from industrial emissions by many nations in the 1980s and 1990s, with the largest contributions from leaded gasoline emissions. In contrast, the deep water (>1000 m) Pb concentrations were lower (6-37 pmol kg -1 ), and constituted a mix of background (natural) Pb and anthropogenic Pb inputs from preceding decades. Deep water below the Western Subarctic Gyre (WSAG) contained more industrial Pb than below the NPSG, which was attributed to a calculated 60-fold greater flux of particulate Pb to abyssal waters near the Asian continent. Assuming Pb isotope compositions in the North Pacific Ocean were homogeneous prior to large-scale 20th century anthropogenic inputs, this evidence suggests a relatively faster change in Pb isotope ratios of North Pacific deep water below the WSAG versus the NPSG.

Using soil properties to predict in vivo bioavailability of lead in soils.

PubMed

Wijayawardena, M A Ayanka; Naidu, Ravi; Megharaj, Mallavarapu; Lamb, Dane; Thavamani, Palanisami; Kuchel, Tim

2015-11-01

Soil plays a significant role in controlling the potential bioavailability of contaminants in the environment. In this study, eleven soils were used to investigate the relationship between soil properties and relative bioavailability (RB) of lead (Pb). To minimise the effect of source of Pb on in vivo bioavailability, uncontaminated study soils were spiked with 1500 mg Pb/kg soil and aged for 10-12 months prior to investigating the relationships between soil properties and in vivo RB of Pb using swine model. The biological responses to oral administration of Pb in aqueous phase or as spiked soils were compared by applying a two-compartment pharmacokinetic model to blood Pb concentration. The study revealed that RB of Pb from aged soils ranged from 30±9% to 83±7%. The very different RB of Pb in these soils was attributed to variations in the soils' physico-chemical properties. This was established using sorption studies showing: firstly, Freundlich partition coefficients that ranged from 21 to 234; and secondly, a strongly significant (R(2)=0.94, P<0.001) exponential relationship between RB and Freundlich partition coefficient (Kd). This simple exponential model can be used to predict relative bioavailability of Pb in contaminated soils. To the best of our knowledge, this is the first such model derived using sorption partition coefficient to predict the relative bioavailability of Pb. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preferential adsorption and surface precipitation of lead(II) ions onto anatase in artificially contaminated Dixie clay.

PubMed

Suzuki, Tasuma; Okita, Miyu; Kakoyama, Satoshi; Niinae, Masakazu; Nakata, Hideki; Fujii, Hiroshi; Tasaka, Yukio

2017-09-15

During TEM-EDS (transmission electron microscopy coupled with an X-ray energy dispersive spectrometer) analysis of Dixie clay artificially contaminated with Pb(II), we observed that Pb(II) was preferentially adsorbed and precipitated on the surface of TiO 2 . To deepen the understanding of the mechanism and importance of this phenomenon, batch sorption experiments, XANES (X-ray absorption near edge spectroscopy) analysis, and sequential extraction analysis were performed. The TiO 2 in Dixie clay was found to be anatase, and anatase showed a higher Pb(II) sorption propensity than rutile, α-FeOOH, and one of two MnO 2 investigated in this study. Our experimental results indicated that the Pb precipitates preferentially formed on the surface of anatase was Pb(II) hydroxide or Pb(II) oxide. Additionally, sequential extraction analysis showed that at least 32% and 42% of Pb(II) was sorbed onto anatase in the Dixie clay contaminated with a Pb content of 736mg Pb/kg and 1,958mg Pb/kg, respectively. These results demonstrated that in addition to Fe and Mn oxides that are well-known metal oxides that serve as sinks for Pb(II) in the soil environment, TiO 2 is also a metal oxide that controls the behavior and fate of Pb(II) in soils. Copyright © 2017 Elsevier B.V. All rights reserved.

Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine.

PubMed

Kristensen, Louise Jane; Taylor, Mark Patrick; Evans, Andrew James

2016-07-01

Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Increased accumulation of Pb and Cd from contaminated soil with Scirpus triqueter by the combined application of NTA and APG.

PubMed

Hu, Xiaoxin; Liu, Xiaoyan; Zhang, Xinying; Cao, Liya; Chen, Jing; Yu, Hang

2017-12-01

Phytoremediation of heavy metals contaminated soils shows many advantages and it can be improved by adding chelating agents and surfactants. In this study, pot culture experiments were set up to explore the effect of alone application of nitrilotriacetic acid (NTA) and combined application of NTA and alkyl polyglucoside (APG) on changes in absorption and adsorption of heavy metals by root of Scirpus triqueter and bioaccumulation of metals in single or co-contamination. Different additives were added into the soils artificially after 10 d and heavy metals extracted from different plant tissues were analyzed after 60 d. Results showed that more cadmium (Cd) was adsorbed on the root surface while more lead (Pb) was absorbed in root interior with the combined application of NTA and APG during phytoremediation of single contaminated soil. In co-contaminated soils, such a combined application not only strengthened the plant growth, but also promoted accumulation of Pb and Cd by Scirpus triqueter. NTA improved absorption amounts of Pb (9.7-fold) and Cd (1.0-fold) in root interior significantly. APG induced more metals to gather on the root surface in the presence of NTA and the adsorption amounts of Pb and Cd ranged from 26.2 and 17.7 mg kg -1 to 412 and 46.0 mg kg -1 respectively. Besides, the coexistence metal increased bioaccumulation of another metal under combined application of NTA and APG in co-contamination of Pb and Cd. In conclusion, the combined application of NTA and APG would be beneficial to accumulate Pb and Cd from contaminated soils by Scirpus triqueter. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosorption of lead phosphates by lead-tolerant bacteria as a mechanism for lead immobilization.

PubMed

Rodríguez-Sánchez, Viridiana; Guzmán-Moreno, Jesús; Rodríguez-González, Vicente; Flores-de la Torre, Juan Armando; Ramírez-Santoyo, Rosa María; Vidales-Rodríguez, Luz Elena

2017-08-01

The study of metal-tolerant bacteria is important for bioremediation of contaminated environments and development of green technologies for material synthesis due to their potential to transform toxic metal ions into less toxic compounds by mechanisms such as reduction, oxidation and/or sequestration. In this study, we report the isolation of seven lead-tolerant bacteria from a metal-contaminated site at Zacatecas, México. The bacteria were identified as members of the Staphylococcus and Bacillus genera by microscopic, biochemical and 16S rDNA analyses. Minimal inhibitory concentration of these isolates was established between 4.5 and 7.0 mM of Pb(NO 3 ) 2 in solid and 1.0-4.0 mM of Pb(NO 3 ) 2 in liquid media. A quantitative analysis of the lead associated to bacterial biomass in growing cultures, revealed that the percentage of lead associated to biomass was between 1 and 37% in the PbT isolates. A mechanism of complexation/biosorption of lead ions as inorganic phosphates (lead hydroxyapatite and pyromorphite) in bacterial biomass, was determined by Fourier transform infrared spectroscopy and X-ray diffraction analyses. Thus, the ability of the lead-tolerant isolates to transform lead ions into stable and highly insoluble lead minerals make them potentially useful for immobilization of lead in mining waste.

Measurement by ICP-MS of lead in plasma and whole blood of lead workers and controls.

PubMed Central

Schütz, A; Bergdahl, I A; Ekholm, A; Skerfving, S

1996-01-01

OBJECTIVES: To test a simple procedure for preparing samples for measurement of lead in blood plasma (P-Pb) and whole blood (B-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), to measure P-Pb and B-Pb in lead workers and controls, and to evaluate any differences in the relation between B-Pb and P-Pb between people. METHODS: P-Pb and B-Pb were measured by ICP-MS in 43 male lead smelter workers and seven controls without occupational exposure to lead. For analysis, plasma and whole blood were diluted 1 in 4 and 1 in 9, respectively, with a diluted ammonia solution containing Triton-X 100 and EDTA. The samples were handled under routine laboratory conditions, without clean room facilities. RESULTS: P-Pb was measured with good precision (CV = 5%) even at concentrations present in the controls. Freeze storage of the samples had no effect on the results. The detection limit was 0.015 microgram/l. The P-Pb was 0.15 (range 0.1-0.3) microgram/l in controls and 1.2 (0.3-3.6) micrograms/l in lead workers, although the corresponding B-Pbs were 40 (24-59) micrograms/l and 281 (60-530) micrograms/l (1 microgram Pb/I = 4.8 nmol/l). B-Pb was closely associated with P-Pb (r = 0.90). The association was evidently non-linear; the ratio B-Pb/P-Pb decreased with increasing P-Pb. CONCLUSIONS: By means of ICP-MS and a simple dilution procedure, P-Pb may be measured accurately and with good precision down to concentrations present in controls. Contamination of blood at sampling and analysis is no major problem. With increasing P-Pb, the percentage of lead in plasma increases. In studies of lead toxicity, P-Pb should be considered as a complement to current indicators of lead exposure and risk. PMID:9038796

Coral-based history of lead and lead isotopes of the surface Indian Ocean since the mid-20th century

NASA Astrophysics Data System (ADS)

Lee, Jong-Mi; Boyle, Edward A.; Suci Nurhati, Intan; Pfeiffer, Miriam; Meltzner, Aron J.; Suwargadi, Bambang

2014-07-01

Anthropogenic lead (Pb) from industrial activities has greatly altered the distribution of Pb in the present-day oceans, but no continuous temporal Pb evolution record is available for the Indian Ocean despite rapidly emerging industries around the region. Here, we present the coral-inferred annual history of Pb concentration and isotope ratios in the surface Indian Ocean since the mid-20th century (1945-2010). We analyzed Pb in corals from the Chagos Archipelago, western Sumatra and Strait of Singapore - which represent the central Indian Ocean via nearshore sites. Overall, coral Pb/Ca increased in the mid-1970s at all the sites. However, coral Pb isotope ratios evolve distinctively at each site, suggesting Pb contamination arises from different sources in each case. The major source of Pb in the Chagos coral appears to be India's Pb emission from leaded gasoline combustion and coal burning, whereas Pb in western Sumatra seems to be largely affected by Indonesia's gasoline Pb emission with additional Pb inputs from other sources. Pb in the Strait of Singapore has complex sources and its isotopic composition does not reflect Pb from leaded gasoline combustion. Higher 206Pb/207Pb and 208Pb/207Pb ratios found at this site may reflect the contribution of Pb from coals and ores from southern China, Indonesia, and Australia, and local Pb sources in the Strait of Singapore. It is also possible that the Pb isotope ratios of Singapore seawater were elevated through isotope exchange with natural fluvial particles considering its delta setting.

Effects of Microbial and Phosphate Amendments on the Bioavailability of Lead (Pb) in Shooting Range Soil

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

Brigmon, Robin; Wilson, Christina; Knox, Anna

Heavy metals including lead (Pb) are released continually into the environment as a result of industrial, recreational, and military activities. Lead ranked number two on the CERCLA Priority List of Hazardous Substances and was identified as a major hazardous chemical found on 47% of USEPA's National Priorities List sites (Hettiarachchi and Pierzynski 2004). In-situ remediation of lead (Pb) contaminated soils may be accomplished by changing the soil chemistry and structure with the application of microbial and phosphate amendments. Soil contaminated with lead bullets was collected from the surface of the berm at Savannah River Site (SRS) Small Arms Training Academymore » (SATA) in Aiken, SC. While uncontaminated soils typically have Pb levels ranging from 2 to 200 mg/kg (Berti et al. 1998), previous analysis show Pb levels of the SATA berm to reach 8,673 mg/kg. Biosurfactants are surface-active compounds naturally produced by soil bacteria that can bind metals. Biosurfactants have a wide variety of chemical structures that reduce interfacial surface tensions (Jennings and Tanner 2000) and have demonstrated efficient metal complexion (Lin 1996). Biosurfactants also have the potential to change the availability of natural organic matter (Strong-Gunderson 1995). Two types of bacteria, Alcaligenes piechaudii and Pseudomonas putida, were employed as amendments based on their ability to produce biosurfactants and survive in metal-contaminated soils. Apatites (calcium phosphate compounds) are important in the formation of Pb phosphates. Pb phosphates form rapidly when phosphate is available and are the most stable environmental form of lead in soil (Ruby et al.1998). Pyromorphites in particular remain insoluble under a wide range of environmental conditions (Zhang et al. 1998). The three apatites evaluated in the current study were North Carolina apatite (NCA), Florida apatite (FA), and biological apatite (BA). BA is ground fish bone that has few impurities such as As, Cr, or U and contains about 27% total phosphate, most of which is available. FA and NCA are two types of rock phosphates that release small amounts of phosphate over time. Total phosphate is around 30% with only 1-2% phosphate available (Knox et al. 2005). In this study, we describe the influence of combining the two microbial and three phosphate amendments on reducing lead bioavailability in shooting range soil.« less

Arsenic and Lead Uptake by Vegetable Crops Grown on an Old Orchard Site Amended with Compost

PubMed Central

McBride, Murray B.; Shayler, Hannah A.; Russell-Anelli, Jonathan M.; Spliethoff, Henry M.; Marquez-Bravo, Lydia G.

2015-01-01

The potential for lead (Pb) and arsenic (As) transfer into vegetables was studied on old orchard land contaminated by lead arsenate pesticides. Root (carrot), leafy (lettuce), and vegetable fruits (green bean, tomato) were grown on seven “miniplots” with soil concentrations ranging from near background to ≈ 800 and ≈ 200 mg kg−1 of total Pb and As, respectively. Each miniplot was divided into sub-plots and amended with 0% (control), 5% and 10% (by weight) compost and cropped for 3 years. Edible portions of each vegetable were analyzed for total Pb and As to test the effect of organic matter on transfer of these toxic elements into the crop. Vegetable Pb and As concentrations were strongly correlated to soil total Pb and As, respectively, but not to soil organic matter content or compost addition level. For Pb vegetable concentrations, carrot ≥ lettuce > bean > tomato. For As, lettuce > carrot > bean > tomato. A complementary single-year study of lettuce, arugula, spinach, and collards revealed a beneficial effect of compost in reducing both Pb and As concentrations in leafy vegetables. Comparisons of all measured vegetable concentrations to international health-based standards indicate that tomatoes can be grown without exceeding standards even in substantially Pb- and As-contaminated soils, but carrots and leafy greens may exceed standards when grown in soils with more than 100–200 mg kg−1 Pb. Leafy greens may also exceed health-based standards in gardens where soil As is elevated, with arugula having a particularly strong tendency to accumulate As. PMID:26900187

High Content of Lead Is Associated with the Softness of Drinking Water and Raised Cardiovascular Morbidity: A Review.

PubMed

Bjørklund, Geir; Dadar, Maryam; Chirumbolo, Salvatore; Aaseth, Jan

2018-04-14

Daily ingestion of lead (Pb), even through piped drinking water, has long time been an important issue of concern, attracting for decades research in environmental science and toxicology, and again comes to prominence because of recent high-profile cases of exposure of populations in several countries to Pb-contaminated water. Numerous studies have reported an association between Pb in water and the risk of cardiovascular pathologies. Low levels of magnesium and calcium, i.e., low degree of hardness of the drinking water, may accentuate Pb leaching from water pipes and furthermore increase Pb absorption. This review evaluates the evidence for an association between Pb exposure from drinking water and cardiovascular end points in human populations.

Safety of gardening on lead- and arsenic-contaminated urban brownfields.

PubMed

Defoe, Phillip P; Hettiarachchi, Ganga M; Benedict, Christopher; Martin, Sabine

2014-11-01

Elevated levels of lead (Pb) and arsenic (As) are not uncommon for urban soils. Test plots were established at urban gardens in Tacoma and Seattle, WA. The Tacoma site was contaminated with Pb (51-312 mg kg) and As (39-146 mg kg), and the Seattle site had high Pb soil concentrations ranging from 506 to 2022 mg kg and As concentrations of <20 mg kg. The efficacy of biosolids mix and compost amendment in reducing Pb and As concentrations in three vegetables (carrots, lettuce, and tomatoes) and the bioaccessibility of soil Pb and As were evaluated. Food-chain transfer of Pb and As were evaluated by measuring plant Pb and As concentrations after kitchen-style washing, a laboratory cleaning procedure, or peeling. The experimental design was a randomized complete block with a split-plot arrangement. Tacoma site treatments included a Class A biosolids mix (TAGRO) with dolomite, and soil at the Seattle site was amended with Cedar-Grove compost (CGC) plus dolomite. TAGRO amendment diluted soil Pb by 10 to 23% and As by 12 to 25% at the Tacoma site, and CGC + dolomite resulted in 20 to 50% dilution in soil Pb at the Seattle site. Both amendments reduced Pb concentrations in vegetables by 50 to 71%, and As reductions ranged from 46 to 80%. At the Tacoma site, Pb concentrations (dry weight basis) in carrots, lettuce, and tomatoes ranged from 8.89 to 25.0, from 0.37 to 3.83, and from 0.54 to 1.24 mg kg, respectively. Plant As concentrations were below 703 μg kg (dry weight) for the vegetables and followed the order lettuce > carrot > tomato. Food-chain transfer of Pb and As in vegetables grown in contaminated urban soils were reduced by laboratory cleaning. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of lead mineralogy on soil washing enhanced by ferric salts as extracting and oxidizing agents.

PubMed

Yoo, Jong-Chan; Park, Sang-Min; Yoon, Geun-Seok; Tsang, Daniel C W; Baek, Kitae

2017-10-01

In this study, we evaluated the feasibility of using ferric salts including FeCl 3 and Fe(NO 3 ) 3 as extracting and oxidizing agents for a soil washing process to remediate Pb-contaminated soils. We treated various Pb minerals including PbO, PbCO 3 , Pb 3 (CO 3 ) 2 (OH) 2 , PbSO 4 , PbS, and Pb 5 (PO 4 ) 3 (OH) using ferric salts, and compared our results with those obtained using common washing agents of HCl, HNO 3 , disodium-ethylenediaminetetra-acetic acid (Na 2 -EDTA), and citric acid. The use of 50 mM Fe(NO 3 ) 3 extracted significantly more Pb (above 96% extraction) from Pb minerals except PbSO 4 (below 55% extraction) compared to the other washing agents. In contrast, washing processes using FeCl 3 and HCl were not effective for extraction from Pb minerals because of PbCl 2 precipitation. Yet, the newly formed PbCl 2 could be dissolved by subsequent wash with distilled water under acidic conditions. When applying our washing method to remediate field-contaminated soil from a shooting range that had high concentrations of Pb 3 (CO 3 ) 2 (OH) 2 and PbCO 3 , we extracted more Pb (approximately 99% extraction) from the soil using 100 mM Fe(NO 3 ) 3 than other washing agents at the same process conditions. Our results show that ferric salts can be alternative washing agents for Pb-contaminated soils in view of their extracting and oxidizing abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Stabilization Treatment of Pb and Zn in Contaminated Soils and Mechanism Studies].

PubMed

Xie, Wei-qiang; Li, Xiao-mingi; Chen, Can; Chen, Xun-feng; Zhong, Yu; Zhong, Zhen-yu; Wan, Yong; Wang, Yan

2015-12-01

In the present work, the combined application of potassium dihydrogen phosphate, quick lime and potassium chloride was used to immobilize the Pb and Zn in contaminated soils. The efficiency of the process was evaluated through leaching tests and Tessier sequential extraction procedure. The mechanism of stabilization was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) to reveal the mechanism of stabilization. The results showed that the stabilizing efficiency of Pb contaminated soils was above 80% and the leaching concentrations of Pb, Zn were far below the threshold when the ratio of exogenous P and soil (mol · mol⁻¹) was 2:1-4: 1, the dosing ratio of CaO was 0.1%-0.5% ( mass fraction) and the dosage of potassium chloride was 0.02-0. 04 mol. Meanwhile, Pb and Zn in soil were transformed from the exchangeable fraction into residual fraction, which implied that the migration of Pb, Zn in soil could be confined by the stabilization treatment. XRD and SEM analysis revealed that Ca-P-Pb precipitation, lead orthophosphate [PbHP0₄, Pb₃ (PO₄)₂], pyromorphite (Pb-PO₄-Cl/OH) and mixed heavy metal deposits (Fe-PO₄- Ca-Pb-Zn-OH) could be formed after solidification/stabilization in which Pb and Zn could be wrapped up to form a solidified composition and to prevent leaching.

Remediation potential of mulch for removing lead.

PubMed

Jang, A; Bishop, P L

2012-01-01

Hardwood bark mulch has good physicochemical properties for the adsorption of lead (Pb(II)). Batch tests were conducted to obtain the sorption coefficient of Pb(II) in mulch. The results of the Freundlich model were not in as good agreement as for the case of the Langmuir model. In addition, a laboratory-scale mulch permeable reactive barrier (PRB) system was designed for the treatment of Pb(II)-contaminated groundwater. The mulch PRB system, using a mulch layer, can potentially be used in the subsurface for cost-effective and in situ transformation of the Pb(II) into environmentally acceptable forms. From the Pb(II) breakthrough curve, the mulch becomes saturated more quickly at higher flow rates.

Determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination.

PubMed

Saha, Jayanta Kumar; Panwar, N R; Singh, M V

2010-09-01

Cadmium and lead are important environmental pollutants with high toxicity to animals and human. Soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. Present experiment was carried out with the objective of quantifying the limits of Pb and Cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. Two separate sets of pot experiment were carried out for these two heavy metals with graded levels of application doses of Pb at 0.4-150 mg/kg and Cd at 0.02-20 mg/kg to an acidic light textured alluvial soil. Spinach crop was grown for 50 days on these treated soils after a stabilization period of 2 months. Upper limit of background concentration levels (C(ul)) of these metals were calculated through statistical approach from the heavy metals concentration values in leaves of spinach crop grown in farmers' fields. Lead and Cd concentration limits in soil were calculated by dividing C(ul) with uptake response slope obtained from the pot experiment. Cumulative loading limits (concentration limits in soil minus contents in uncontaminated soil) for the experimental soil were estimated to be 170 kg Pb/ha and 0.8 kg Cd/ha. Based on certain assumptions on application rate and computed cumulative loading limit values, maximum permissible Pb and Cd concentration values in municipal solid waste (MSW) compost were proposed as 170 mg Pb/kg and 0.8 mg Cd/kg, respectively. In view of these limiting values, about 56% and 47% of the MSW compost samples from different cities are found to contain Pb and Cd in the safe range.

Long-term response of an arctic fiord system to lead-zinc mining and submarine disposal of mine waste (Maarmorilik, West Greenland).

PubMed

Søndergaard, Jens; Asmund, Gert; Johansen, Poul; Rigét, Frank

2011-06-01

Contamination by lead (Pb) and zinc (Zn) was studied in seawater, sediments, seaweeds and blue mussels near the former Black Angel Pb-Zn Mine in Maarmorilik, West Greenland. The mine operated during the period 1973-90 when mine waste (tailings and later waste rock) was discharged directly into the sea. Metal concentrations peaked during the mining period and Pb and Zn in seawater within the discharge area were measured up to 440 and 790 μg L⁻¹, respectively. Pb in fiord sediments, seaweeds and blue mussels just outside the discharge area were measured in concentrations up to 190, 84 and 2650 and Zn up to 300, 360 and 1190 μg g⁻¹ dry wt., respectively. Within the discharge area, seawater metal concentrations (especially Pb) decreased abruptly after mine closure. Metals concentrations in sediments and biota, however, decreased more slowly and two decades after mine closure seaweeds and blue mussels were still contaminated 12 km from the mine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Elevated CO2 increases glomalin-related soil protein (GRSP) in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils.

PubMed

Jia, Xia; Zhao, Yonghua; Liu, Tuo; Huang, Shuping; Chang, Yafei

2016-11-01

Glomalin-related soil protein (GRSP), which contains glycoproteins produced by arbuscular mycorrhizal fungi (AMF), as well as non-mycorrhizal-related heat-stable proteins, lipids, and humic materials, is generally categorized into two fractions: easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP). GRSP plays an important role in soil carbon (C) sequestration and can stabilize heavy metals such as lead (Pb), cadmium (Cd), and manganese (Mn). Soil contamination by heavy metals is occurring in conjunction with rising atmospheric CO 2 in natural ecosystems due to human activities. However, the response of GRSP to elevated CO 2 combined with heavy metal contamination has not been widely reported. Here, we investigated the response of GRSP to elevated CO 2 in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils. Elevated CO 2 (700 μmol mol -1 ) significantly increased T- and EE- GRSP concentrations in soils contaminated with Cd, Pb or Cd + Pb. GRSP contributed more carbon to the rhizosphere soil organic carbon pool under elevated CO 2  + heavy metals than under ambient CO 2 . The amount of Cd and Pb bound to GRSP was significantly higher under elevated (compared to ambient) CO 2 ; and elevated CO 2 increased the ratio of GRSP-bound Cd and Pb to total Cd and Pb. However, available Cd and Pb in rhizosphere soil under increased elevated CO 2 compared to ambient CO 2 . The combination of both metals and elevated CO 2 led to a significant increase in available Pb in rhizosphere soil compared to the Pb treatment alone. In conclusion, increased GRSP produced under elevated CO 2 could contribute to sequestration of soil pollutants by adsorption of Cd and Pb. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of metals pollution on agricultural soil surrounding a lead-zinc mining area in the Karst region of Guangxi, China.

PubMed

Zhang, Chaolan; Li, Zhongyi; Yang, Weiwei; Pan, Liping; Gu, Minghua; Lee, DoKyoung

2013-06-01

Soil samples were collected on farmland in a lead-zinc mining area in the Karst region of Guangxi, China. The contamination of the soil by eight metals (Cd, Hg, As, Cu, Pb, Cr, Zn, Ni) was determined. Among all these metals, Cd is the most serious pollutant in this area. Zn, Hg as well asPb can also be measured at high levels, which may affect the crop production. All other metals contributed marginally to the overall soil contamination. Besides the evaluation of single metals, the Nemerow synthetic index indicated that the soil is not suitable for agricultural use.

Enhanced Accumulation of Copper and Lead in Amaranth (Amaranthus paniculatus), Indian Mustard (Brassica juncea) and Sunflower (Helianthus annuus)

PubMed Central

Rahman, Motior M.; Azirun, Sofian M.; Boyce, Amru N.

2013-01-01

Background Soil contamination by copper (Cu) and lead (Pb) is a widespread environmental problem. For phytoextraction to be successful and viable in environmental remediation, strategies that can improve plant uptake must be identified. In the present study we investigated the use of nitrogen (N) fertilizer as an efficient way to enhance accumulation of Cu and Pb from contaminated industrial soils into amaranth, Indian mustard and sunflower. Methods/Principal Findings Plants were grown in a greenhouse and fertilized with N fertilizer at rates of 0, 190 and 380 mg kg−1 soil. Shoots, roots and total accumulation of Cu and Pb, transfer factor (TF), translocation index were assessed to evaluate the transport and translocation ability of tested plants. Addition of N fertilizer acidified the industrial soil and caused the pH to decrease to 5.5 from an initial pH of 6.9. Industrial soil amended with N fertilizer resulted in the highest accumulation of Pb and Cu (for Pb 10.1–15.5 mg kg−1, for Cu 11.6–16.8 mg kg−1) in the shoots, which was two to four folds higher relative to the concentration in roots in all the three plants used. Sunflower removed significantly higher Pb (50–54%) and Cu (34–38%) followed by amaranth and Indian mustard from industrial soils with the application of N fertilizer. The TF was <1 while the shoot and root concentration (SC/RC) ratios of Pb and Cu were between 1.3–4.3 and 1.8–3.8, respectively, regardless of plant species. Conclusions Sunflower is the best plant species to carry out phytoextraction of Pb and Cu. In contrast, Pb and Cu removal by Indian mustard and amaranth shows great potential as quick and short duration vegetable crops. The results suggest that the application of N fertilizer in contaminated industrial soil is an effective amendment for the phytoextraction of Pb and Cu from contaminated industrial soils. PMID:23667546

Influence of farmyard manure on retention and availability of nickel, zinc and lead in metal-contaminated calcareous loam soils

USDA-ARS?s Scientific Manuscript database

Continuous irrigation of crops with untreated municipal effluent can result in the accumulation of nickel (Ni), zinc (Zn), and lead (Pb) in soils and translocation to the plants. Application of farm yard manure (FYM) to metal-contaminated soils may increase or decrease the availability and retention...

Phosphate Treatment of Lead-Contaminated Soil: Effects on ...

EPA Pesticide Factsheets

Water quality threats associated with using phosphate-based amendments to remediate Pb-contaminated soils are a concern, particularly in riparian areas. This study investigated the effects of P application rates to a Pb-contaminated alluvial soil on Pb and P loss via surface water runoff, Pb accumulation in tall fescue (Festuca arundinacea Schreb; Kentucky 31), and Pb speciation. An alluvial soil was treated with triple superphosphate at P to Pb molar ratios of 0:1(control), 4:1, 8:1, and 16:1. After a 6- mo reaction period, rainfall simulation (RFS) studies were conducted, followed by tall fescue establishment and a second set of RFS studies (1 yr after treatment). Results from the first RFS (unvegetated) demonstrated that the total Pb and P concentrations in the effluents of 8:1 and 16:1 (P:Pb molar ratio) treatment levels were significantly greater (p 55%. X-ray absorption near-edge structure spectroscopy data showed that pyromorphite [Pb5(PO4)3OH,Cl,F] abundance ranged from 0% (control) to 32% (16:1 P:Pb; 1 yr after treatment) of the total soil Pb. Although P treatment stimulated pyromorphite formation, pyromorphite abundance was comparable between the P-treated soils. These findings suggest that a 4:1 (P:Pb molar ratio) P treatment may be a sufficient means of reducing Pb bioavailability while minimizing concerns related to P loss in an alluvial setting. The purpose of the current research was to examine the feasability of using phosphate based ammend

Nature and extent of metal-contaminated soils in urban environments (keynote talk).

PubMed

Mielke, Howard W

2016-08-01

Research on the nature and extent of metal-contaminated soil began with an urban garden study in Baltimore, MD (USA). Largest quantities of soil metals were clustered in the inner city with lesser amounts scattered throughout metropolitan Baltimore. The probability values of metal clustering varied from P value 10(-15)-10(-23) depending on element. The inner-city clustering of lead (Pb) could not be explained by Pb-based paint alone. A major Pb source was tetraethyl lead (TEL), developed as an anti-knock agent for use in vehicle fuel, thereby making highway traffic flow a toxic substance delivery system in cities. Further study in Minneapolis and St. Paul confirmed the clustering of inner-city soil metals, especially Pb. Based on the evidence, the Minnesota State Legislature petitioned Congress to curtail Pb additives resulting in the rapid phasedown of TEL on January 1, 1986, 10 years ahead of the EPA scheduled ban. Further research in New Orleans, Louisiana (NOLA), verified the link between soil Pb, blood Pb, morbidity, and societal health. Although Pb is a known cause of clinical impairment, there is no known effective medical intervention for reducing children's blood Pb exposure. Ingestion and inhalation are routes of exposure requiring prevention, and soil is a reservoir of Pb. Children's blood Pb exposure observed in pre-Hurricane Katrina (August 29, 2005) NOLA underwent substantial decreases 10 years post-Katrina due to many factors including input of low Pb sediment residues by the storm surge and the introduction of low Pb landscaping materials from outside of the city. Investigation on the topic is ongoing.

Phytoremediation of lead (Pb) and arsenic (As) by Melastoma malabathricum L. from contaminated soil in separate exposure.

PubMed

Selamat, S Norleela; Abdullah, S Rozaimah Sheikh; Idris, M

2014-01-01

This study was conducted to investigate the uptake of lead (Pb) and arsenic (As) from contaminated soil using Melastoma malabathricum L. species. The cultivated plants were exposed to As and Pb in separate soils for an observation period of 70 days. From the results of the analysis, M. malabathricum accumulated relatively high range of As concentration in its roots, up to a maximum of 2800 mg/kg. The highest accumulation of As in stems and leaves was 570 mg/kg of plant. For Pb treatment, the highest concentration (13,800 mg/kg) was accumulated in the roots of plants. The maximum accumulation in stems was 880 mg/kg while maximum accumulation in leaves was 2,200 mg/kg. Only small amounts of Pb were translocated from roots to above ground plant parts (TF < 1). However, a wider range of TF values (0.01-23) for As treated plants proved that the translocation of As from root to above ground parts was greater. However, the high capacity of roots to take up Pb and As (BF > 1) is indicative this plants is a good bioaccumulator for these metals. Therefore, phytostabilisation is the mechanism at work in M. malabathricum's uptake of Pb, while phytoextraction is the dominant mechanism with As.

Assessment of lead pollution in topsoils of a southern Italy area: Analysis of urban and peri-urban environment.

PubMed

Guagliardi, Ilaria; Cicchella, Domenico; De Rosa, Rosanna; Buttafuoco, Gabriele

2015-07-01

Exposure to lead (Pb) may affect adversely human health. Mapping soil Pb contents is essential to obtain a quantitative estimate of potential risk of Pb contamination. The main aim of this paper was to determine the soil Pb concentrations in the urban and peri-urban area of Cosenza-Rende to map their spatial distribution and assess the probability that soil Pb concentration exceeds a critical threshold that might cause concern for human health. Samples were collected at 149 locations from residual and non-residual topsoil in gardens, parks, flower-beds, and agricultural fields. Fine earth fraction of soil samples was analyzed by X-ray Fluorescence spectrometry. Stochastic images generated by the sequential Gaussian simulation were jointly combined to calculate the probability of exceeding the critical threshold that could be used to delineate the potentially risky areas. Results showed areas in which Pb concentration values were higher to the Italian regulatory values. These polluted areas were quite large and likely, they could create a significant health risk for human beings and vegetation in the near future. The results demonstrated that the proposed approach can be used to study soil contamination to produce geochemical maps, and identify hot-spot areas for soil Pb concentration. Copyright © 2015. Published by Elsevier B.V.

Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes.

PubMed

Zhang, Tao; Zou, Hua; Ji, Minhui; Li, Xiaolin; Li, Liqiao; Tang, Tang

2014-02-01

Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb-EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The "approaching anode electrokinetic remediation" process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.

Lead Accumulation by Tall Fescue (Festuca arundinacea Schreb.) Grown on a Lead-Contaminated Soil

PubMed Central

Begonia, M. T.; Begonia, G. B.; Ighoavodha, M.; Gilliard, D.

2005-01-01

Phytoextraction is gaining acceptance as a cost-effective and environmentally friendly phytoremediation strategy for reducing toxic metal levels from contaminated soils. Cognizant of the potential of this phytoremediation technique as an alternative to expensive engineering-based remediation technologies, experiments were conducted to evaluate the suitability of some plants as phytoextraction species. From one of our preliminary studies, we found that tall fescue (Festuca arundinacea Schreb. cv. Spirit) can tolerate and accumulate significant amounts of lead (Pb) in its shoots when grown in Pb-amended sand. To further evaluate the suitability of tall fescue as one of the potential crop rotation species for phytoextraction, a study was conducted to determine whether the addition of ethylenediaminetetraacetic acid (EDTA) alone or in combination with acetic acid can further enhance the shoot uptake of Pb. Seeds were planted in 3.8 L plastic pots containing top soil, peat, and sand (4:2:1, v:v:v) spiked with various levels (0,1000, 2000 mg Pb/kg dry soil) of lead. At six weeks after planting, aqueous solutions (0, 5 mmol/kg dry soil) of EDTA and acetic acid (5 mmol/kg dry soil) were applied to the root zone, and all plants were harvested a week later. Results revealed that tall fescue was relatively tolerant to moderate levels of Pb as shown by non-significant differences in root and shoot biomass among treatments. An exception to this trend however, was the slight reduction in root and shoot biomass of plants exposed to the highest Pb level in combination with the two chelates. Root Pb concentration increased with increasing level of soil-applied Pb. Further increases in root Pb concentrations were attributed to chelate amendments. Translocation index, which is a measure of the partitioning of the metal to the shoots, was significantly enhanced with chelate addition especially when both EDTA and acetic acid were used. Chelate-induced increases in translocation indices correspondingly led to higher shoot Pb concentrations. PMID:16705822

Low Contribution of PbO 2 -Coated Lead Service Lines to Water Lead Contamination at the Tap

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

Triantafyllidou, Simoni; Schock, Michael R.; DeSantis, Michael K.

2015-02-24

To determine if residential water sampling corroborates the expectation that formation of stable PbO2 coatings on lead service lines (LSLs) provides an effective lead release control strategy, lead profile sampling was evaluated for eight home kitchen taps in three U.S. cities with observed PbO2-coated LSLs (Newport, Rhode Island; Cincinnati and Oakwood, Ohio). After various water standing times, these LSLs typically released similar or lower peak lead levels (1 to 18 μg/L) than the lead levels from the respective kitchen faucets (1 to 130 μg/L), and frequently 50–80% lower than the lead levels typically reported from Pb(II)-coated LSLs in comparable publishedmore » sampling studies. Prolonged stagnation (10–101 h) at the Cincinnati sites produced varying results. One site showed minimal (0–4 μg/L) increase in lead release from the PbO2-coated LSL, and persistence of free chlorine residual. However, the other site showed up to a 3-fold increase proportional to standing time, with essentially full depletion of the chlorine residual. Overall, lead release was consistently much lower than that reported in studies of Pb(II)-coated LSL scales, suggesting that natural formation of PbO2 in LSLs is an effective lead “corrosion” control strategy.« less

Lead distributions and risks in New Orleans following Hurricanes Katrina and Rita.

PubMed

Abel, Michael T; Cobb, George P; Presley, Steven M; Ray, Gary L; Rainwater, Thomas R; Austin, Galen P; Cox, Stephen B; Anderson, Todd A; Leftwich, Blair D; Kendall, Ronald J; Suedel, Burton C

2010-07-01

During the last four years, significant effort has been devoted to understanding the effects that Hurricanes Katrina and Rita had on contaminant distribution and redistribution in New Orleans, Louisiana, USA, and the surrounding Gulf Coast area. Elevated concentrations were found for inorganic contaminants (including As, Fe, Pb, and V), several organic pollutants (polycyclic aromatic hydrocarbons, pesticides, and volatiles) and high concentration of bioaerosols, particularly Aeromonas and Vibrio. Data from different research groups confirm that some contaminant concentrations are elevated, that existing concentrations are similar to historical data, and that contaminants such as Pb and As may pose human health risks. Two data sets have been compiled in this article to serve as the foundation for preliminary risk assessments within greater New Orleans. Research from the present study suggests that children in highly contaminated areas of New Orleans may experience Pb exposure from soil ranging from 1.37 microg/d to 102 microg/d. These data are critical in the evaluation of children's health. Copyright (c) 2010 SETAC.

Comparative Assessment of Soil Contamination by Lead and Heavy Metals in Riparian and Agricultural Areas (Southern Québec, Canada)

PubMed Central

Saint-Laurent, Diane; Hähni, Marlies; St-Laurent, Julien; Baril, Francis

2010-01-01

Soils contaminated with hydrocarbons (C10–C50), PAHS, lead and other heavy metals were recently found in the banks of two major rivers in southern Québec. Alluvial soils are contaminated over a distance of 100 kilometers. Eight sampling sites, including some located in agriculture areas (farm woodlots) have been selected to compare air pollution (aerosol fallout and rainout) and river pollution values. The concentrations detected in soil profiles for As, Cd and Pb vary between 3.01 to 37.88 mg kg−1 (As), 0.11 to 0.81 mg kg−1 (Cd) 12.32 to 149.13 mg kg−1 (Pb). These metallic elements are considered highly toxic and can harm wildlife and human health at high levels. The maximum concentration of Pb (149.13 mg kg−1) in soils of the riparian zone is twelve times higher than the average Pb concentration found in a natural state evaluated at 15.3 mg kg−1 (SD 17.5). Pb concentrations in soils of agricultural areas (woodland control sites) range between 12 and 22 mg kg−1, and given that these values are recorded in surrounding cultivated land, the issue of the quality of agricultural products (crops and forage) to feed livestock or destined for human consumption must be further addressed in detail. PMID:20948950

Comparative assessment of soil contamination by lead and heavy metals in riparian and agricultural areas (southern Québec, Canada).

PubMed

Saint-Laurent, Diane; Hähni, Marlies; St-Laurent, Julien; Baril, Francis

2010-08-01

Soils contaminated with hydrocarbons (C(10)-C(50)), PAHS, lead and other heavy metals were recently found in the banks of two major rivers in southern Québec. Alluvial soils are contaminated over a distance of 100 kilometers. Eight sampling sites, including some located in agriculture areas (farm woodlots) have been selected to compare air pollution (aerosol fallout and rainout) and river pollution values. The concentrations detected in soil profiles for As, Cd and Pb vary between 3.01 to 37.88 mg kg(-1) (As), 0.11 to 0.81 mg kg(-1) (Cd) 12.32 to 149.13 mg kg(-1) (Pb). These metallic elements are considered highly toxic and can harm wildlife and human health at high levels. The maximum concentration of Pb (149.13 mg kg(-1)) in soils of the riparian zone is twelve times higher than the average Pb concentration found in a natural state evaluated at 15.3 mg kg(-1) (SD 17.5). Pb concentrations in soils of agricultural areas (woodland control sites) range between 12 and 22 mg kg(-1), and given that these values are recorded in surrounding cultivated land, the issue of the quality of agricultural products (crops and forage) to feed livestock or destined for human consumption must be further addressed in detail.

The continuing impact of lead dust on children's blood lead: comparison of public and private properties in New Orleans.

PubMed

Mielke, Howard W; Gonzales, Chris R; Mielke, Paul W

2011-11-01

Compared with a maximum collective lead (Pb) estimate of ∼1811 metric tons (MT) in exterior paint on 86,000 New Orleans houses, Pb additives in gasoline were estimated at ∼12,000 MT in New Orleans, yielding ∼9100 MT Pb exhausted as aerosols from vehicles; ∼4850 MT were particles>10 μm and ∼4200 MT were particles <0.25 μm. To evaluate pre-Hurricane Katrina soil Pb and children's blood Pb at public housing and private residential properties in the inner-city compared with the outer city of New Orleans. This study includes 224 soil samples from 10 public housing properties and 363 soil samples from residential private properties within an 800 m radius of centroids of public housing census tracts. The Louisiana Childhood Lead Poisoning Prevention Program data from 2000 to 2005 (pre-Hurricane Katrina) was the source for 9807 children's blood Pb (μg/dL) results. Soil and blood Pb data were grouped by public housing census tracts and private residential properties. This study uses Multi-Response Permutation Procedures for statistical analysis. Brick public properties in the city core had significantly more soil Pb contamination and higher prevalence of elevated children's blood Pb than same-aged brick public properties in the outer areas of the city. The pre-Hurricane Katrina New Orleans concentration of Pb dust in the inner-city soil displayed a median of 438 mg/kg or 3.7 times larger than Pb dust in outlying areas where the median soil Pb was 117 mg/kg (p-value=2.9×10(-15)). Also, the pre-Hurricane Katrina prevalence of children's blood Pb≥10 μg/dL was 22.9% within the inner-city compared with 9.1% in the outer areas of New Orleans (p-value=3.4×10(-74)). Comparing the quantities of Pb dust from paint and Pb additives to gasoline, this study supports the later source as a more plausible explanation for the differences in soil Pb and children's blood Pb within public and private housing in the higher traffic congested inner-city core compared with the lower traffic congested outer areas of New Orleans. Similar patterns of environmental Pb dust contamination and childhood Pb exposure are expected in all cities. Copyright © 2011 Elsevier Inc. All rights reserved.

TETRAVALENT LEAD: A HITHERTO UNRECOGNIZED CONTROL OF TAP WATER LEAD CONTAMINATION

EPA Science Inventory

Almost all of the theoretical framework underlying the control of plumbosolvency and lead release has been based on the presumption that the lead release is explicable by Pb(II) solubility, aqueous speciation, and reaction kinetics. Utilities struggling to comply with the Lead an...

Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability

NASA Astrophysics Data System (ADS)

Li, Honghong; Liu, Yuting; Chen, Yanhui; Wang, Shanli; Wang, Mingkuang; Xie, Tuanhui; Wang, Guo

2016-08-01

This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar. Compared to the control treatment, amendment with 5% biochar resulted in 54 and 94% decreases in the acid soluble and CaCl2-extractable Pb, respectively, in soils containing rice plants at the maturity stage. The amount of Fe-plaque on root surfaces and the Pb concentrations of the Fe-plaque were also reduced in biochar amended soils. Furthermore, lead species in rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES), and although Pb-ferrihydrite complexes dominated Pb inventories, increasing amounts of organic complexes like Pb-pectins and Pb-cysteine were found in roots from the 5% biochar treatments. Such organic complexes might impede Pb translocation from root to shoot and subsequently reduce Pb accumulation in rice with biochar amendment.

Prediction of blood lead levels in children before and after remediation of soil samples in the upper Meza Valley, Slovenia.

PubMed

Jez, Erika; Lestan, Domen

2015-10-15

The Meza Valley, Slovenia, has been contaminated by Pb smelting, resulting in an epidemic of lead poisoning in childhood. The potential of remediation with EDTA soil washing to mitigate the risk from Pb poisoning was investigated by applying the Integrated Exposure Uptake Bio-kinetic (IEUBK) model. Soils from 79 locations were collected and the total and bio-accessible Pb concentrations were determined before and after extraction with 60 mmol kg(-1) EDTA. Extraction reduced the soil Pb concentration in towns of Mezica, Zerjav and Crna by 53, 67 and 62%, respectively, and the concentration of in vitro bio-accessible Pb in the simulated human gastric phase by 2.6-, 3.2- and 2.9-times, respectively. The predictions of the IEUBK model based on Pb contamination data were verified with data on blood Pb levels in children. The IEUBK model predicted that, after soil remediation, the number of locations at which the expected blood Pb level in children was higher than the stipulated 10 μg d L(-1) would decrease by 90, 38 and 91% in the towns of Mezica, Zerjav and Crna, respectively. The results confirmed the feasibility of soil washing with EDTA as an efficient remediation measure in Mezica and Crna and advice for soil capping/removal for the most polluted town of Zerjav. Copyright © 2015 Elsevier B.V. All rights reserved.

Micro-x-ray fluorescence, micro-x-ray absorption spectroscopy, and micro-x-ray diffraction investigation of lead speciation after the addition of different phosphorus amendments to a smelter-contaminated soil.

PubMed

Baker, Lucas R; Pierzynski, Gary M; Hettiarachchi, Ganga M; Scheckel, Kirk G; Newville, Matthew

2014-03-01

The stabilization of Pb on additions of P to contaminated soils and mine spoil materials has been well documented. It is clear from the literature that different P sources result in different efficacies of Pb stabilization in the same contaminated material. We hypothesized that the differences in the efficacy of Pb stabilization in contaminated soils on fluid or granular P amendment addition is due to different P reaction processes in and around fertilizer granules and fluid droplets. We used a combination of several synchrotron-based techniques (i.e., spatially resolved micro-X-ray fluorescence, micro-X-ray absorption near-edge structure spectroscopy, and micro-X-ray diffraction) to speciate Pb at two incubation times in a smelter-contaminated soil on addition of several fluid and granular P amendments. The results indicated that the Pb phosphate mineral plumbogummite was an intermediate phase of pyromorphite formation. Additionally, all fluid and granular P sources were able to induce Pb phosphate formation, but fluid phosphoric acid (PA) was the most effective with time and distance from the treatment. Granular phosphate rock and triple super phosphate (TSP) amendments reacted to generate Pb phosphate minerals, with TSP being more effective at greater distances from the point of application. As a result, PA and TSP were the most effective P amendments at inducing Pb phosphate formation, but caution needs to be exercised when adding large amounts of soluble P to the environment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Enhancing Potentially Plant-Available Lead Concentrations in Contaminated Residential Soils Using a Biodegradable Chelating Agent

NASA Astrophysics Data System (ADS)

Andra, S.; Datta, R.; Sarkar, D.; Saminathan, S.

2007-12-01

Chelation of heavy metals is an important factor in enhancing metal solubility and, hence, metal availability to plants to promote phytoremediation. In the present study, we compared the effects of application of a biodegradable chelating agent, namely, ethylenediaminedisuccinic acid (EDDS) on enhancing plant available form of lead (Pb) in Pb-based paint contaminated residential soils compared to that of a more commonly used, but non-biodegradable chelate, i.e., ethylenediaminetetraacetic acid (EDTA). Development of a successful phytoremediation model for metals such as Pb depends on a thorough understanding of the physical and chemical properties of the soil, along with the optimization of a chelate treatment to mobilize Pb from `unavailable' pools to potentially plant available fraction. In this context, we set out to perform batch incubation experiments to investigate the effectiveness of the two aforementioned chelates in enhancing plant available Pb at four different concentrations (0, 5, 10 and 15 mM/kg soil) and three treatment durations (0, 10 and 30 days). We selected 12 contaminated residential soils from two major metropolitan areas (San Antonio, TX and Baltimore, MD) with varying soil physico-chemical properties - the soils from San Antonio were primarily alkaline and those from Baltimore were typically acidic. Total soil Pb concentrations ranged between 256 mg/kg and 4,182 mg/kg. Our results show that both chelates increased the solubility of Pb, otherwise occluded in the complex soil matrix. For both EDTA and EDDS, the exchangeable concentrations of soil Pb also increased with increase in chelate concentration and incubation time. The most effective treatment was 15 mM chelate kg-1 soil incubated for 30 days, which caused many fold increase in potentially plant available Pb (a combination of the soluble and exchangeable fractions) relative to the unamended controls. Step wise multiple linear regression analysis using chelate-extractable Pb and soil properties showed that plant available Pb fraction could be assessed from the two inter-related soil parameters: soil organic matter and soil pH. Although EDTA was more effective in Pb solubilization than EDDS, the rapid kinetics of the Pb-EDTA complexation process and the prolonged persistence of EDTA in soils pose a potential groundwater contamination problem via metal leaching. In contrast to EDTA, EDDS addition caused relatively slow release of Pb from the soil matrix. The biodegradable nature (and short half life) of EDDS in soils makes it a promising chelating agent for use as soil amendment to enhance Pb solubilization and hence, potential plant uptake.

Lead Concentrations in Soils and Some Wild Plant Species Along Two Busy Roads in Pakistan.

PubMed

Khalid, Noreen; Hussain, Mumtaz; Young, Hillary S; Ashraf, Muhammad; Hameed, Mansoor; Ahmad, Rashid

2018-02-01

This study assessed the level of Pb in soil and five wild plant species (Calotropis procera, Datura alba, Parthenium hysterophorus, Cenchrus ciliaris and Ricinus communis) during all the four seasons. Two busy roads varying in age and traffic volume were selected i.e., Faisalabad-Sargodha road (FSR) and Pindi Bhattian to Lillah (M-2) in the Punjab, Pakistan. Results showed raised levels of Pb in both plants and soil samples along both roads. The range of Pb concentration in plants was 0.08-3.98 and 1.95-4.74 mg kg - 1 for soil. Higher Pb contamination was recorded along FSR road as compared to M-2. Among seasons, the higher Pb concentration was found during summer, probably due to very high temperature. Among all the plants studied, Calotropis procera accumulated the highest level (3.98 mg kg - 1 dry wt.) of Pb; Thus, it can be used as good biomonitor/phytoremediator at Pb contaminated areas.

Evaluation of meat and bone meal combustion residue as lead immobilizing material for in situ remediation of polluted aqueous solutions and soils: "chemical and ecotoxicological studies".

PubMed

Deydier, E; Guilet, R; Cren, S; Pereas, V; Mouchet, F; Gauthier, L

2007-07-19

As a result of bovine spongiform encephalopathy (BSE) crisis, meat and bone meal (MBM) production can no longer be used to feed cattle and must be safely disposed of or transformed. MBM specific incineration remains an alternative that could offer the opportunity to achieve both thermal valorization and solid waste recovery as ashes are calcium phosphate-rich material. The aim of this work is to evaluate ashes efficiency for in situ remediation of lead-contaminated aqueous solutions and soils, and to assess the bioavailability of lead using two biological models, amphibian Xenopus laevis larvae and Nicotiana tabaccum tobacco plant. With the amphibian model, no toxic or genotoxic effects of ashes are observed with concentrations from 0.1 to 5 g of ashes/L. If toxic and genotoxic effects of lead appear at concentration higher than 1 mg Pb/L (1 ppm), addition of only 100 mg of ashes/L neutralizes lead toxicity even with lead concentration up to 10 ppm. Chemical investigations (kinetics and X-ray diffraction (XRD) analysis) reveals that lead is quickly immobilized as pyromorphite [Pb10(PO4)6(OH)2] and lead carbonate dihydrate [PbCO(3).2H2O]. Tobacco experiments are realized on contaminated soils with 50, 100, 2000 and 10000 ppm of lead with and without ashes amendment (35.3g ashes/kg of soil). Tobacco measurements show that plant elongation is bigger in an ashes-amended soil contaminated with 10000 ppm of lead than on the reference soil alone. Tobacco model points out that ashes present two beneficial actions as they do not only neutralize lead toxicity but also act as a fertilizer.

Metal uptake by homegrown vegetables – The relative importance in human health risk assessments at contaminated sites

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

Augustsson, Anna L.M., E-mail: anna.augustsson@lnu.se; Uddh-Söderberg, Terese E.; Hogmalm, K. Johan

Risk assessments of contaminated land often involve the use of generic bioconcentration factors (BCFs), which express contaminant concentrations in edible plant parts as a function of the concentration in soil, in order to assess the risks associated with consumption of homegrown vegetables. This study aimed to quantify variability in BCFs and evaluate the implications of this variability for human exposure assessments, focusing on cadmium (Cd) and lead (Pb) in lettuce and potatoes sampled around 22 contaminated glassworks sites. In addition, risks associated with measured Cd and Pb concentrations in soil and vegetable samples were characterized and a probabilistic exposure assessmentmore » was conducted to estimate the likelihood of local residents exceeding tolerable daily intakes. The results show that concentrations in vegetables were only moderately elevated despite high concentrations in soil, and most samples complied with applicable foodstuff legislation. Still, the daily intake of Cd (but not Pb) was assessed to exceed toxicological thresholds for about a fifth of the study population. Bioconcentration factors were found to vary more than indicated by previous studies, but decreasing BCFs with increasing metal concentrations in the soil can explain why the calculated exposure is only moderately affected by the choice of BCF value when generic soil guideline values are exceeded and the risk may be unacceptable. - Highlights: • Uptake of Cd and Pb by lettuce and potatoes increased with soil contamination. • Consumption of homegrown vegetables may lead to a daily Cd intake above TDIs. • The variability in the calculated BCFs is high when compared to previous studies. • Exposure assessments are most sensitive to the choice of BCFs at low contamination.« less

Characteristics of lead corrosion scales formed during drinking water distribution and their potential influence on the release of lead and other contaminants.

PubMed

Kim, Eun Jung; Herrera, Jose E

2010-08-15

Destabilization of the corrosion scale present in lead pipes used in drinking water distribution systems is currently considered a major problem for municipalities serviced in part by lead pipes. Although several lead corrosion strategies have been deployed with success, a clear understanding of the chemistry of corrosion products present in the scale is needed for an effective lead control. This contribution focuses on a comprehensive characterization of the layers present in the corrosion scale formed on the inner surfaces of lead pipes used in the drinking water distribution system of the City on London, ON, Canada. Solid corrosion products were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Toxic elements accumulated in the corrosion scale were also identified using inductively coupled plasma (ICP) spectrometry after acid digestion. Based on the XRD results, hydrocerussite was identified as the major lead crystalline corrosion phase in most of the pipes sampled, while cerussite was observed as the main crystalline component only in a few cases. Lead oxides including PbO(2) and Pb(3)O(4) were also observed in the inner layers of the corrosion scale. The presence of these highly oxidized lead species is rationalized in terms of the lead(II) carbonate phase transforming into lead(IV) oxide through an intermediate Pb(3)O(4) (2Pb(II)O x Pb(IV)O(2)) phase. In addition to lead corrosion products, an amorphous aluminosilicate phase was also identified in the corrosion scale. Its concentration is particularly high at the outer surface layers. Accumulation of toxic contaminants such as As, V, Sb, Cu, and Cr was observed in the corrosion scales, together with a strong correlation between arsenic accumulation and aluminum concentration.

Characterization of the lead smelter slag in Santo Amaro, Bahia, Brazil.

PubMed

Lima, L R P de Andrade; Bernardez, L A

2011-05-30

For 33 years, a primary lead smelter operated in Santo Amaro (Brazil). Since the 1970s, large amounts of Pb and Cd have been widely documented in the blood and hair of people living near the smelter. The plant closed down in 1993, and several years later, the Pb levels in the blood of children under 4 years of age living near the smelter were high, where the disposed lead slag was suspected to be the main source of this contamination. The objective of this study is to elucidate the source of the Pb contamination and any other potentially toxic contamination, focusing on the characterization of the slag. The samples used for this characterization study were taken from the slag heaps. The results of the chemical analysis showed that the major constituents of the slag, in decreasing order of wt%, were the following: Fe(2)O(3) (28.10), CaO (23.11), SiO(2) (21.39), ZnO (9.47), MgO (5.44), PbO (4.06), Al(2)O(3) (3.56), C (2.26), MnO (1.44), Na(2)O (0.27), S (0.37), K(2)O (0.26), and TiO(2) (0.25). The Cd content of the slag was 57.3mg/kg, which is relatively low. The X-ray diffraction and the electron probe microanalyzer X-ray mapping indicated that the major phases in the slag were wüstite, olivine, kirschsteinite, and franklinite. Only spheroidal metallic Pb was found in the slag. The leaching study showed that the slag was stable at a pH greater than 2.8, and only in an extremely acidic environment was the solubilization of the Pb enhanced significantly. The solubilization of Zn was very limited in the acidic and alkaline environments. These results can be explained by the limited leachability of the metallic Pb and Zn-bearing compounds. The leaching study used TCLP, SPLP, and SWEP and indicated that the lead slag was stable in weak acidic environments for short contact times. Copyright © 2011 Elsevier B.V. All rights reserved.

ZnO nanoflower-based photoelectrochemical DNAzyme sensor for the detection of Pb2+.

PubMed

Zhang, Bintian; Lu, Lili; Hu, Qichang; Huang, Feng; Lin, Zhang

2014-06-15

Lead contamination is now widespread, and exposure to lead may cause adverse effects on human beings. In this study, a photoelectrochemical sensor based on flower-like ZnO nanostructures was developed for Pb(2+) detection, using a Pb(2+)-dependent DNAzyme as the recognition unit and a double-strand DNA intercalator, Ru(bpy)2(dppz)(2+) (bpy=2,2'-bipyridine, dppz=dipyrido[3,2-a:2',3'-c] phenazine) as the photoelectrochemical signal reporter. The ZnO nanoflower was fabricated on an indium tin oxide (ITO) electrode by the convenient hydrothermal decomposition method. The morphology and photoelectrochemical property of the ZnO nanoflowers were characterized by SEM, XRD and photocurrent measurements. DNAzyme-substrate duplex was assembled on an ITO/ZnO electrode through electrostatic adsorption. In the presence of Pb(2+), RNA-cleavage activity of the DNAzyme was activated and its substrate strand was cleaved, resulting in the release of Ru(bpy)2(dppz)(2+) from the DNA film and the concomitant photocurrent decrease. The detection principle was verified by fluorescence measurements. Under the optimized conditions, a linear relationship between photocurrent and Pb(2+) concentration was obtained over the range of 0.5-20 nM, with a detection limit of 0.1 nM. Interference from other common metal ions was found negligible. Applicability of the sensor was demonstrated by analyzing lead level in human serum and Pb(2+) spiked water samples. This facile and economical sensor system showed high sensitivity and selectivity, thus can be potentially applied for on-site monitoring of lead contaminant. Copyright © 2014 Elsevier B.V. All rights reserved.

High-precision Pb isotopic measurements of teeth and environmental samples from Sofia (Bulgaria): insights for regional lead sources and possible pathways to the human body

NASA Astrophysics Data System (ADS)

Kamenov, George D.

2008-08-01

High-precision Pb isotopic measurements on teeth and possible sources in a given area can provide important insights for the lead (Pb) sources and pathways in the human body. Pb isotopic analyses on soils from the area of Sofia, Bulgaria show that Pb is contributed by three end-members represented by two natural sources and leaded gasoline. Sequential leaching experiments reveal that the alumosilicate fraction of the soils is mainly controlled by natural Pb derived from two mountain massifs bordering the city. Around 1/3 to a half of the Pb in the soil leachates, however, can be explained by contamination from leaded gasoline. Contemporary teeth from Sofia residents show very similar Pb isotopic compositions to the soil leachates, also indicating that around 1/3 to a half of the Pb can be explained by derivation from leaded gasoline. The remarkable isotopic similarities between the teeth and the most labile fractions of the local soils suggest that the lead can be derived from the latter. Pb incorporation in the human body via soil-plant-human or soil-plant-animal-human chains is unlikely due to the fact that no significant farming occurs in the city area. The isotopic compositions of the local soil labile fractions can be used as approximation of the bioaccessible lead for humans. Considering all possible scenarios it appears that soil and/or soil-born dust inhalation and/or ingestion is the most probable pathway for incorporation of local soil lead in the local population. The high-precision Pb isotope data presented in this work indicate that apparently the local soil is what plays major role in the human Pb exposure.

SPECTROSCOPIC SPECIATION AND QUANTIFICATION OF LEAD IN PHOSPHATE AMENDED SOILS

EPA Science Inventory

The immobilization of Pb in contaminated soils as pyromorphite [Pb₅(PO₄)₃CI, OH, F] through the addition of various phosphate amendments has gained much attention in the remediation community. However, it is difficult to fully determine the specia...

EMPIRICAL MODELS OF PB AND CD PARTITIONING USING DATA FROM 13 SOILS, SEDIMENTS AND AQUIFER MATERIALS

EPA Science Inventory

Lead (Pb) and cadmium (Cd) are two of the most common toxicants found in contaminated environments. Because solubilization of these metallic elements from the solid phase can influence their fate, transport and bioavailability, the partitioning coefficient (Kd) for these metals ...

Effects of byproducts amended lead contaminated urban soils on collard yield

USDA-ARS?s Scientific Manuscript database

Lead (Pb) has been used to produce materials and manufactured products for many years. In urban areas and industrial centers atmospheric lead deposition could be very high. Urban environments in general received high deposition of lead due to leaded gasoline use, industrial activity and abandoned ...

Effect of lead stress on mineral content and growth of wheat (Triticum aestivum) and spinach (Spinacia oleracea) seedlings

PubMed Central

Lamhamdi, Mostafa; El Galiou, Ouiam; Bakrim, Ahmed; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel; Aarab, Ahmed; Lafont, René

2012-01-01

Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential element for plants, but they absorb it when it is present in their environment, especially in rural areas when the soil is polluted by automotive exhaust and in fields contaminated with fertilizers containing heavy metal impurities. To investigate lead effects on nutrient uptake and metabolism, two plant species, spinach (Spinacia oleracea) and wheat (Triticum aestivum), were grown under hydroponic conditions and stressed with lead nitrate, Pb(NO3)2, at three concentrations (1.5, 3, and 15 mM). Lead is accumulated in a dose-dependent manner in both plant species, which results in reduced growth and lower uptake of all mineral ions tested. Total amounts and concentrations of most mineral ions (Na, K, Ca, P, Mg, Fe, Cu and Zn) are reduced, although Mn concentrations are increased, as its uptake is reduced less relative to the whole plant’s growth. The deficiency of mineral nutrients correlates in a strong decrease in the contents of chlorophylls a and b and proline in both species, but these effects are less pronounced in spinach than in wheat. By contrast, the effects of lead on soluble proteins differ between species; they are reduced in wheat at all lead concentrations, whereas they are increased in spinach, where their value peaks at 3 mM Pb. The relative lead uptake by spinach and wheat, and the different susceptibility of these two species to lead treatment are discussed. PMID:23961216

Risk assessment test for lead bioaccessibility to waterfowl in mine-impacted soils

USGS Publications Warehouse

Furman, O.; Strawn, D.G.; Heinz, G.H.; Williams, B.

2006-01-01

Due to variations in soil physicochemical properties, species physiology, and contaminant speciation, Pb toxicity is difficult to evaluate without conducting in vivo dose-response studies. Such tests, however, are expensive and time consuming, making them impractical to use in assessment and management of contaminated environments. One possible alternative is to develop a physiologically based extraction test (PBET) that can be used to measure relative bioaccessibility. We developed and correlated a PBET designed to measure the bioaccessibility of Pb to waterfowl (W-PBET) in mine-impacted soils located in the Coeur d'Alene River Basin, Idaho. The W-PBET was also used to evaluate the impact of P amendments on Pb bioavailability. The W-PBET results were correlated to waterfowl-tissue Pb levels from a mallard duck [Anas platyrhynchos (L.)] feeding study. The W-PBET Pb concentrations were significantly less in the P-amended soils than in the unamended soils. Results from this study show that the W-PBET can be used to assess relative changes in Pb bioaccessibility to waterfowl in these mine-impacted soils, and therefore will be a valuable test to help manage and remediate contaminated soils.

Zinc speciation in proximity to phosphate application points in a lead/zinc smelter-contaminated soil.

PubMed

Baker, Lucas R; Pierzynski, Gary M; Hettiarachchi, Ganga M; Scheckel, Kirk G; Newville, Matthew

2012-01-01

The use of P to immobilize Pb in contaminated soils has been well documented. However, the influence of P on Zn speciation in soils has not been extensively examined, and these two metals often occur as co-contaminants. We hypothesized that additions of P to a Pb/Zn-contaminated soil would induce Zn phosphate mineral formation and fluid P sources would be more effective than granular P amendments. A combination of different synchrotron-based techniques, namely, spatially resolved micro-X-ray fluorescence (μ-XRF), micro-extended X-ray absorption fine structure spectroscopy (μ-EXAFS), and micro-X-ray diffraction (μ-XRD), were used to speciate Zn at two incubation times in the proximity of application points (0 to 4 mm) for fluid and granular P amendments in a Pb/Zn smelter-contaminated soil. Phosphate rock (PR), triple super phosphate (TSP), monoammonium phosphate (MAP), and fluid ammonium polyphosphate induced Zn phosphate formation. Ammonium polyphosphate was more effective at greater distances (up to 3.7 mm) from the point of P application. Phosphoric acid increased the presence of soluble Zn species because of increased acidity. Soluble Zn has implications with respect to Zn bioavailability, which may negatively impact vegetation and other sensitive organisms. Although additions of P immobilize Pb, this practice needs close monitoring due to potential increases in Zn solubility in a Pb/Zn smelter-contaminated soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Lead isotopic fingerprinting of aerosols to characterize the sources of atmospheric lead in an industrial city of India

NASA Astrophysics Data System (ADS)

Sen, Indra S.; Bizimis, Michael; Tripathi, Sachchida Nand; Paul, Debajyoti

2016-03-01

Anthropogenic Pb in the environment is primarily sourced from combustion of fossil fuel and high-temperature industries such as smelters. Identifying the sources and pathways of anthropogenic Pb in the environment is important because Pb toxicity is known to have adverse effects on human health. Pb pollution sources for America, Europe, and China are well documented. However, sources of atmospheric Pb are unknown in India, particularly after leaded gasoline was phased out in 2000. India has a developing economy with a rapidly emerging automobile and high temperature industry, and anthropogenic Pb emission is expected to rise in the next decade. In this study, we report on the Pb-isotope compositions and trace metal ratios of airborne particulates collected in Kanpur, a large city in northern part of India. The study shows that the PM10 aerosols had elevated concentration of Cd, Pb, Zn, As, and Cu in the Kanpur area, however their concentrations are well below the United States Environmental Protection Agency chronic exposure limit. Lead isotopic and trace metal data reveal industrial emission as the plausible source of anthropogenic Pb in the atmosphere in Kanpur. However, Pb isotopic compositions of potential source end-members are required to fully evaluate Pb contamination in India over time. This is the first study that characterizes the isotopic composition of atmospheric Pb in an Indian city after leaded gasoline was phased out by 2000.

Metal Immobilization Influence On Bioavailability And Remediation For Urban Environments

EPA Science Inventory

Immobilization of soil contaminants, such as lead, via phosphate amendments to alter the chemical environment of metals into highly insoluble forms is a well established process. The literature has documented numerous examples of highly contaminated Pb sites at shooting ranges, b...

Ten-Year Monitored Natural Recovery of Lead-Contaminated Mine Tailing in Klity Creek, Kanchanaburi Province, Thailand

PubMed Central

Phenrat, Tanapon; Otwong, Ashijya; Chantharit, Aphichart; Lowry, Gregory V.

2016-01-01

Background: Klity Creek has become Thailand’s first official remediation ordered by the court in 2013, 15 years after the spill of lead (Pb)-contaminated mine tailing into the creek. The Pollution Control Department (PCD) decided to restore the creek through monitored natural recovery (MNR) since 2006 but has not been successful. Interestingly, the most recent remediation plan in 2015 will still apply MNR to five out of the seven portions of the creek, despite no scientific feasibility evaluation of using MNR to restore the creek. Objective: This study qualitatively and quantitatively evaluated the feasibility of using MNR to clean up the creek in order to protect the Klity children from excess Pb exposure. Methods: We analyzed the physical and chemical transformation of Pb contaminated sediment in the creek and developed a remedial action goal and cleanup level using the Integrated Exposure Uptake Biokinetic model (IEUBK). We empirically determined the natural recovery (NR) potentials and rates using 10 years of data monitoring the water and sediment samples from eight monitoring stations (KC1 to KC8). Results: Klity Creek has NR potential for water except at KC2, which is closest to the spill and the other improperly managed Pb sources. However, the creek has no NR potential for sediment except at the KC8 location (NR rate = 11.1 ± 3.0 × 10–3 month–1) farthest from the spill. Conclusion: The MNR method is not suitable to use as the sole remedial approach for Klity Creek (KC2 to KC7). Although MNR is applicable at KC8, it may require up to 377 ± 76 years to restore the sediment to the background Pb concentration. Citation: Phenrat T, Otwong A, Chantharit A, Lowry GV. 2016. Ten-year monitored natural recovery of lead-contaminated mine tailing in Klity Creek, Kanchanaburi Province, Thailand. Environ Health Perspect 124:1511–1520; http://dx.doi.org/10.1289/EHP215 PMID:27157823

Alluvial and riparian soils as major sources of lead exposure in young children in the Philippines: the role of floods.

PubMed

Ostrea, Enrique M; Ostrea, Angelo M; Villanueva-Uy, Ma Esterlita; Chiodo, Lisa; Janisse, James

2015-04-01

The objective of this paper was to determine the prevalence and sources of high lead (Pb) exposure among children in Bulacan, Philippines. A total of 150 children (6-7 years old) and their caregivers were studied. Lead was analyzed in children hair and deciduous teeth. Sources of lead exposure were determined by caregiver interview and Pb analysis of house soil, drinking faucet water, air, and water from seven Bulacan rivers. Lead was positive in 91.3% of children's hair (MC or median concentration = 8.9 μg/g; range = 0-38.29), in 46.2% of the teeth (MC = 0.000 μg/mg in positive samples; range = 0.00-0.020), in 100% of soil (MC = 27.06 mg/kg; range = 3.05-1155.80), in 21.1% of air (MC = 0 μg/Ncm; range = 0-0.10), in 4% of house, faucet water (MC = 0.0 ppm; range = 0-40). There was a significant correlation (Spearman's rho) between Pb in children's hair and soil (r = 0.195; p = 0.017) and between Pb in house water and outdoor air (r = 0.616; p = 0.005). There is no significant correlation between Pb in children's hair and teeth. None of the potential sources of Pb from interview were related to lead exposure in the children. Water from seven Bulacan rivers was 100% positive for lead (MC = 70.00 ppb; range = 30-90). Widespread flooding with river overflow occurred in Bulacan in 2009 which likely caused lead contamination of the soil. There was no significant difference in the lead concentration of the soil whether near or far from the river (p = 0.205, Mann-Whitney U test). High lead exposure in children in Bulacan is likely from soil contaminated by lead-polluted rivers during flooding. In areas where flooding is common, alluvial and riparian soils from polluted rivers are important sources of lead exposure in children.

Ultrasensitive detection of lead (II) based on fluorescent aptamer-functionalized carbon nanotubes.

PubMed

Taghdisi, Seyed Mohammad; Emrani, Somayeh Sarreshtehdar; Tabrizian, Kaveh; Ramezani, Mohammad; Abnous, Khalil; Emrani, Ahmad Sarreshtehdar

2014-05-01

Lead contamination is a serious environmental problem with toxic effects in human. Here, we developed a simple and sensitive sensing method employing ATTO 647N/aptamer-SWNT ensemble for detection of Pb(2+). This method is based on the super quenching capability of single-walled carbon nanotubes (SWNTs), high affinity of the aptamer toward Pb(2+) and different propensities of ATTO 647N-aptamer and ATTO 647N-aptamer/Pb(2+) complex for adsorption on SWNTs. In the absence of Pb(2+), the fluorescence of ATTO 647N-aptamer is efficiently quenched by SWNTs. Upon addition of Pb(2+), the aptamer binds to its target, leading to the formation of a G-quadruplex/Pb(2+) complex and does not interact with SWNTs and ATTO 647N-aptamer starts fluorescing. This sensor exhibited a high selectivity toward Pb(2+) and a limit of detection (LOD) as low as 0.42 nM was obtained. Also this sensor could be applied for detection of Pb(2+) ions in tap water and biological sample like serum with high sensitivity. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of lead on tolerance, bioaccumulation, and antioxidative defense system of green algae, Cladophora.

PubMed

Cao, De-ju; Shi, Xiao-dong; Li, Hao; Xie, Pan-pan; Zhang, Hui-min; Deng, Juan-wei; Liang, Yue-gan

2015-02-01

Effects of various concentrations (0.5, 1.0, 2.5, 5.0, 7.5, and 10.0 mg/L) of lead (Pb(2+)) on the growth, bioaccumulation, and antioxidative defense system of green algae, Cladophora, was investigated. Low concentrations of Pb(2+) accelerated Cladophora growth, but concentrations of 10.0 mg/L and above inhibited the growth because of the hinderance to photosynthesis. The total soluble sugar content of Cladophora was affected by Pb(2+) treatment, but the protein content showed no significant changes. The malondialdehyde (MDA) content and peroxidase(POD) activity of Cladophora gradually increased whereas superoxide dismutase(SOD) decreased with Pb(2+) concentrations. Catalase (CAT) activity exhibited no significant changes following Pb(2+) treatment. Pb(2+) accumulated in Cladophora and that the lead content in Cladophora was correlated with POD growth, MDA, and Metallothionein (MT). POD and MT play a role in the survival of Cladophora in Pb-contaminated environments. This study suggests that Cladophora can be a choice organism for the phytoremediation of Pb-polluted coastal areas. Copyright © 2014 Elsevier Inc. All rights reserved.

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

PubMed

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

2004-08-01

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

Lead and strontium isotopes as monitors of anthropogenic contaminants in the surficial environment: Chapter 12

USGS Publications Warehouse

Ayuso, Robert A.; Foley, Nora K.

2018-01-01

Isotopic discrimination can be an effective tool in establishing a direct link between sources of Pb contamination and the presence of anomalously high concentrations of Pb in waters, soils, and organisms. Residential wells supplying water containing up to 1600 ppb Pb to houses built on the former Mohr orchards commercial site, near Allentown, Pennsylvania, United States, were evaluated to discern anthropogenic from geogenic sources. Pb and Sr isotopic data and REE data were determined for waters from residential wells, test wells (drilled for this study), and surface waters from pond and creeks. Local soils, sediments, bedrock, Zn-Pb mineralization and coal were also analyzed, together with locally used Pb-As pesticide. Pb isotope data for residential wells, test wells, and surface waters show substantial overlap with Pb data reflecting anthropogenic actions (e.g., burning fossil fuels, industrial and urban processing activities). Limited contributions of Pb from bedrock, soils, and pesticides are evident. High Pb concentrations in the residential waters are likely related to Pb in groundwater accumulating in sediment in the residential water tanks. The Pb isotope features of waters in underlying shallow aquifers that supply residential wells in the region are best interpreted as reflecting a legacy of anthropogenic Pb rather than geogenic Pb.

Optimization of Lead Removal via Napier Grass in Synthetic Brackish Water using Response Surface Model

NASA Astrophysics Data System (ADS)

Hongsawat, P.; Suttiarporn, P.; Wutsanthia, K.; Kongsiri, G.

2018-03-01

The efficiency of the lead (Pb) phytoremediation by Napier grass was studied on the plant’s growth and plant’s tolerance on the Pb toxicity in synthetic brackish water. It was found that the plant was high tolerance to high level of Pb concentration (10 mg/l) in synthetic brackish water. Which revealed on the possibilities of plant’s growth under the presence of Pb contaminated condition. According to the Pb removal efficiency, the highest one (88.63±4.9%) was found at 10 ppm Pb concentration, 0.3 g/l NaCl concentration during the period 45 day. However, this study investigated the optimum condition for lead (Pb) removal from synthetic brackish water using phytoremediation treatment with Napier grass through a Box-Behnken Design. Three operational variables, i.e. Pb concentration (1, 5.5, 10 mg/l), NaCl (0.1, 0.3, 0.5 g/l) and period time (7, 26, 45 day), were determined. The results were provided evidence that the highest Pb removal efficiency (93.56%) from synthetic brackish water via Napier grass was Pb and NaCl concentration at 10 mg/l and 0.5 g/l during 45 day.

Unleaded gasoline as a significant source of Pb emissions in the Subarctic.

PubMed

Chrastný, Vladislav; Šillerová, Hana; Vítková, Martina; Francová, Anna; Jehlička, Jan; Kocourková, Jana; Aspholm, Paul E; Nilsson, Lars O; Berglen, Tore F; Jensen, Henning K B; Komárek, Michael

2018-02-01

After the phasing out of leaded gasoline, Pb emissions to the atmosphere dramatically decreased, and other sources became more significant. The contribution of unleaded gasoline has not been sufficiently recognized; therefore, we evaluated the impact of Pb from unleaded gasoline in a relatively pristine area in Subarctic NE Norway. The influence of different endmembers (Ni slag and concentrate from the Nikel smelter in Russia, PM 10 filters, and traffic) on the overall Pb emissions was determined using various environmental samples (snow, lichens, and topsoils) and Pb isotope tracing. We found a strong relationship between Pb in snow and the Ni smelter. However, lichen samples and most of the topsoils were contaminated by Pb originating from the current use of unleaded gasoline originating from Russia. Historical leaded and recent unleaded gasoline are fully distinguishable using Pb isotopes, as unleaded gasoline is characterized by a low radiogenic composition ( 206 Pb/ 207 Pb = 1.098 and 208 Pb/ 206 Pb = 2.060) and remains an unneglectable source of Pb in the region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimates of potential childhood lead exposure from contaminated soil using the US EPA IEUBK Model in Sydney, Australia.

PubMed

Laidlaw, Mark A S; Mohmmad, Shaike M; Gulson, Brian L; Taylor, Mark P; Kristensen, Louise J; Birch, Gavin

2017-07-01

Surface soils in portions of the Sydney (New South Wales, Australia) urban area are contaminated with lead (Pb) primarily from past use of Pb in gasoline, the deterioration of exterior lead-based paints, and industrial activities. Surface soil samples (n=341) were collected from a depth of 0-2.5cm at a density of approximately one sample per square kilometre within the Sydney estuary catchment and analysed for lead. The bioaccessibility of soil Pb was analysed in 18 samples. The blood lead level (BLL) of a hypothetical 24 month old child was predicted at soil sampling sites in residential and open land use using the United States Environmental Protection Agency (US EPA) Integrated Exposure Uptake and Biokinetic (IEUBK) model. Other environmental exposures used the Australian National Environmental Protection Measure (NEPM) default values. The IEUBK model predicted a geometric mean BLL of 2.0±2.1µg/dL using measured soil lead bioavailability measurements (bioavailability =34%) and 2.4±2.8µg/dL using the Australian NEPM default assumption (bioavailability =50%). Assuming children were present and residing at the sampling locations, the IEUBK model incorporating soil Pb bioavailability predicted that 5.6% of the children at the sampling locations could potentially have BLLs exceeding 5µg/dL and 2.1% potentially could have BLLs exceeding 10µg/dL. These estimations are consistent with BLLs previously measured in children in Sydney. Copyright © 2017 Elsevier Inc. All rights reserved.

An odyssey of environmental pollution: the rise, fall and remobilization of industrial lead in Australia

NASA Astrophysics Data System (ADS)

Taylor, M. P.; Kristensen, L.; Liqin, W.; Harvey, P. J.; Dong, C.; Rouillon, M.

2015-12-01

The use of lead in automobile gasoline resulted in more than 240,000 tonnes of lead being emitted to the Australian environment over its 70-year period of use starting in 1932. The consequences of the emissions and subsequent depositions have resulted in marked contamination of urban and peri-urban aerosols, soils, plants and humans. This paper charts these effects and examines the extent of recovery from one of the most pervasive and persistent environmental pollutants. Lead isotopic composition of Adelaide and Sydney aerosol filters show that air lead composition shifts from values that approximate Broken Hill type ores, the predominant lead source used in gasoline (1.04 206Pb/207Pb and 2.31 208Pb/207Pb), towards ratios that more closely match local uncontaminated soil and bedrock values (Adelaide ~1.19 206Pb/207Pb and ~2.50 208Pb/207Pb; Sydney ~1.15 206Pb/207Pb and 2.48 208Pb/207Pb). Proxy atmospheric measurements from historic wine, lichen and fungi samples extending over 120 years show how both concentration and composition values shifted in the middle to late 20th century to reflect petrol emissions and then recovered rapidly at the end of the century as leaded gasoline consumption declined. For example, lead in wine from South Australia fell from >100 μg/L in the 1960s and 1970s to < 5 μg/L in the 2010s due to the removal of the primary source of atmospheric lead - gasoline. However, measurement of contemporary surface soils, ash produced from wildfires and air filters demonstrate that the effect of depositions persists and industrial lead and other toxic metals (including arsenic, cadmium and nickel) are subject to frequent remobilization. Predicted increases in wildfires and the generation of lead, arsenic and cadmium toxic particulates warrants greater consideration of the risk for vulnerable populations and firefighters who are most exposed.

Geochemical legacies and the future health of cities: A tale of two neurotoxins in urban soils

USGS Publications Warehouse

Fillipelli, Gabriel M.; Risch, Martin R.; Laidlaw, Mark A. S.; Nichols, Deborah E.; Crewe, Julie

2015-01-01

Acute exposure to lead (Pb), a powerful neurotoxin to which children are particularly susceptible, has largely been eliminated in the U.S. and other countries through policy-based restrictions on leaded gasoline and lead-based paints. But the legacy of these sources remains in the form of surface soil Pb contamination, a common problem in cities and one that has only recently emerged as a widespread chronic exposure mechanism in cities. Some urban soils are also contaminated with another neurotoxin, mercury (Hg). The greatest human exposure to Hg is through fish consumption, so eating fish caught in urban areas presents risks for toxic Hg exposure. The potential double impact of chronic exposure to these two neurotoxins is pronounced in cities. Overall, there is a paradigmatic shift from reaction to and remediation of acute exposures towards a more nuanced understanding of the dynamic cycling of persistent environmental contaminants with resultant widespread and chronic exposure of inner-city dwellers, leading to chronic toxic illness and disability at substantial human and social cost.

Advances In Assessing Bioavailability Of Metal(Loid)s In Contaminated Soils

EPA Science Inventory

The term bioavailability has many different meanings across various disciplines of toxicology and pharmacology. Often bioavailability is concerned with human health aspects such as in the case of lead (Pb) ingestion by children. However, some of the most contaminated sites are ...

Synchrotron Analysis Of Metal Immobilization In Sediments

EPA Science Inventory

Heavy metal contamination is a problem at many marine and fresh water environments as a result of industrial and military activities. Metals such as lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) are common contaminants in sediments due to many Navy activities. The mobile...

Relationship Between Total and Bioaccessible Lead on Children's Blood Lead Levels in Urban Residential Philadelphia Soils.

PubMed

Bradham, Karen D; Nelson, Clay M; Kelly, Jack; Pomales, Ana; Scruton, Karen; Dignam, Tim; Misenheimer, John C; Li, Kevin; Obenour, Daniel R; Thomas, David J

2017-09-05

Relationships between total soil or bioaccessible lead (Pb), measured using an in vitro bioaccessibility assay, and children's blood lead levels (BLL) were investigated in an urban neighborhood in Philadelphia, PA, with a history of soil Pb contamination. Soil samples from 38 homes were analyzed to determine whether accounting for the bioaccessible Pb fraction improves statistical relationships with children's BLLs. Total soil Pb concentration ranged from 58 to 2821 mg/kg; the bioaccessible Pb concentration ranged from 47 to 2567 mg/kg. Children's BLLs ranged from 0.3 to 9.8 μg/dL. Hierarchical models were used to compare relationships between total or bioaccessible Pb in soil and children's BLLs. Total soil Pb concentration as the predictor accounted for 23% of the variability in child BLL; bioaccessible soil Pb concentration as the predictor accounted for 26% of BLL variability. A bootstrapping analysis confirmed a significant increase in R 2 for the model using bioaccessible soil Pb concentration as the predictor with 99.0% of bootstraps showing a positive increase. Estimated increases of 1.3 μg/dL and 1.5 μg/dL in BLL per 1000 mg/kg Pb in soil were observed for this study area using total and bioaccessible Pb concentrations, respectively. Children's age did not contribute significantly to the prediction of BLLs.

Contamination and health risks of soil heavy metals around a lead/zinc smelter in southwestern China.

PubMed

Li, Peizhong; Lin, Chunye; Cheng, Hongguang; Duan, Xiaoli; Lei, Kai

2015-03-01

Anthropogenic emissions of toxic metals from smelters are a global problem. The objective of this study was to investigate the distribution of toxic metals in soils around a 60 year-old Pb/Zn smelter in a town in Yunnan Province of China. Topsoil and soil core samples were collected and analyzed to determine the concentrations of various forms of toxic metals. The results indicated that approximately 60 years of Pb/Zn smelting has led to significant contamination of the local soil by Zn, Pb, Cd, As, Sb, and Hg, which exhibited maximum concentrations of 8078, 2485, 75.4, 71.7, 25.3, and 2.58mgkg(-1), dry wet, respectively. Other metals, including Co, Cr, Cu, Mn, Ni, Sc, and V, were found to originate from geogenic sources. The concentrations of smelter driven metals in topsoil decreased with increasing distance from the smelter. The main contamination by Pb, Zn, and Cd was found in the upper 40cm of soil around the Pb/Zn smelter, but traces of Pb, Zn, and Cd contamination were found below 100cm. Geogenic Ni in the topsoil was mostly bound in the residual fraction (RES), whereas anthropogenic Cd, Pb, and Zn were mostly associated with non-RES fractions. Therefore, the smelting emissions increased not only the concentrations of Cd, Pb, and Zn in the topsoil but also their mobility and bioavailability. The hazard quotient and hazard index showed that the topsoil may pose a health risk to children, primarily due to the high Pb and As contents of the soil. Copyright © 2014 Elsevier Inc. All rights reserved.

Mobility and eco-risk of trace metals in soils at the Hailuogou Glacier foreland in eastern Tibetan Plateau.

PubMed

Bing, Haijian; Wu, Yanhong; Zhou, Jun; Liang, Jianhong; Wang, Jipeng; Yang, Zijiang

2016-03-01

The concentrations and fractions of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in soils collected from Hailuogou Glacier foreland in eastern Tibetan Plateau were analyzed to decipher their mobility, and their eco-risk was assessed combined with multiple environmental indices. The concentrations of Cd were more than ten times higher than its local background in the O horizon and nearly three times higher in the A horizon. The concentrations of Pb and Zn were relatively high in the O horizon, whereas that of Cu increased with soil depth. The main fractions of metals in the surface horizons were reducible and acid-soluble for Cd, oxidizable and residual for Cu, reducible and oxidizable for Pb, and reducible and residual for Zn. The metal mobility generally followed the order of Cd > Pb > Zn > Cu in the O horizon and Cd > Pb > Cu > Zn in the A horizon. Sorption and complexation by soil organic matters imparted an important effect on the mobilization and transformation of Cd, Pb, and Zn in the soils. The oxidizable Cu fraction in the soils showed significant correlation with organic matters, and soil pH mainly modulated the acid-soluble and reducible Cu fractions. The concentrations and other environmental indices including contamination factor, enrichment factor, geoaccumulation index, and risk assessment index revealed that Cd reached high contamination and very high eco-risk, Pb had medium contamination but low eco-risk, Zn showed low contamination and low eco-risk, and Cu was not contaminated in the soils. The data indicated that Cd was the priority to concern in the soils of Hailuogou Glacier catchment.

Environmental materials for remediation of soils contaminated with lead and cadmium using maize (Zea mays L.) growth as a bioindicator.

PubMed

Shi, Yu; Huang, Zhanbin; Liu, Xiujie; Imran, Suheryani; Peng, Licheng; Dai, Rongji; Deng, Yulin

2016-04-01

Heavy metal pollution is a severe environmental problem. Remediation of contaminated soils can be accomplished using environmental materials that are low cost and environmentally friendly. We evaluated the individual and combination effects of humic acid (HA), super absorbent polymer (SAP), zeolite (ZE), and fly ash composites (FC) on immobilization of lead (Pb) and cadmium (Cd) in contaminated soils. We also investigated long-term practical approaches for remediation of heavy metal pollution in soil. The biochemical and morphological properties of maize (Zea mays L.) were selected as biomarkers to assess the effects of environmental materials on heavy metal immobilization. The results showed that addition of test materials to soil effectively reduced heavy metal accumulation in maize foliage, improving chlorophyll levels, plant growth, and antioxidant enzyme activity. The test materials reduced heavy metal injury to maize throughout the growth period. A synergistic effect from combinations of different materials on immobilization of Pb and Cd was determined based on the reduction of morphological and biochemical injuries to maize. The combination of zeolite and humic acid was especially effective. Treatment with a combination of HA + SAP + ZE + FC was superior for remediation of soils contaminated with high levels of Pb and Cd.

Influence of compost addition on lead and arsenic bioavailability in reclaimed orchard soil assessed using Porcellio scaber bioaccumulation test

PubMed Central

Udovic, M.; McBride, M.B.

2015-01-01

A long history of lead arsenate application in orchards has led to significant accumulation of Pb and As in the topsoil. Besides the threat that such soils represent for the environment, reclamation of old orchards for agricultural purposes implies the exposure of humans to Pb and As. In this study we assessed the influence of vegetable compost addition (as a sustainable agricultural practice) to contaminated acidic orchard soil on Pb and As bioavailability, assessed with two selective non-exhaustive chemical extractions and with an in vivo bioaccumulation test with an isopod (P. scaber). The treatment with compost caused a significant increase in soil pH and total carbon content, resulting in a consistent decrease of Pb bioavailability. In contrast, the bioavailability of As increased, indicating that a complementary treatment should be used for reducing the bioavailability of As in old orchard soils. This is the first report on the use of As accumulation in P. scaber as a tool for the assessment of As bioavailability in contaminated orchard soil. PMID:22240057

Lead isotope ratios in lichen samples evaluated by ICP-ToF-MS to assess possible atmospheric pollution sources in Havana, Cuba.

PubMed

Alvarez, Alfredo Montero; Estévez Alvarez, Juan R; do Nascimento, Clístenes Williams Araújo; González, Iván Pupo; Rizo, Oscar Díaz; Carzola, Lázaro Lima; Torres, Roberto Ayllón; Pascual, Jorge Gómez

2017-01-01

Epiphytic lichens, collected from 119 sampling sites grown over "Roistonea Royal Palm" trees, were used to assess the spatial distribution pattern of lead (Pb) and identify possible pollution sources in Havana (Cuba). Lead concentrations in lichens and topsoils were determined by flame atomic absorption spectrophotometry and inductively coupled plasma (ICP) atomic emission spectrometry, respectively, while Pb in crude oils and gasoline samples were measured by ICP-time of flight mass spectrometry (ICP-ToF-MS). Lead isotopic ratios measurements for lichens, soils, and crude oils were obtained by ICP-ToF-MS. We found that enrichment factors (EF) reflected a moderate contamination for 71% of the samples (EF > 10). The 206 Pb/ 207 Pb ratio values for lichens ranged from 1.17 to 1.20 and were a mixture of natural radiogenic and industrial activities (e.g., crude oils and fire plants). The low concentration of Pb found in gasoline (<7.0 μg L -1 ) confirms the official statement that leaded gasoline is no longer used in Cuba.

Heavy metal contamination in river water and sediments of the Swarnamukhi River Basin, India: risk assessment and environmental implications.

PubMed

Patel, Priyanka; Raju, N Janardhana; Reddy, B C Sundara Raja; Suresh, U; Sankar, D B; Reddy, T V K

2018-04-01

The concentration of heavy metals was analyzed each of 20 river water, suspended sediments and bed sediments along the stretch of Swarnamukhi River Basin. River water is not contaminated with heavy metals except Fe and Mn. Contamination factor in sediments shows considerable to very high degree contamination with Cr, Cu, Pb and Zn. The sources of these metals could be residential wastes, sewer outfall, fertilizers, pesticides (M-45 + carbondine) and traffic activities apart from natural weathering of granitic rocks present in the basin area. Principal component analyses indicate the interaction between metals in different media. The comparison of metals (Cu, Pb and Zn) in bed sediments of Swarnamukhi River with the Indian and world averages indicates that the values obtained in the basin are above the Indian averages and far below to the world averages. Average shale values and sediment quality guidelines point toward the enrichment and contamination of Cu, Cr, Pb and Zn to several fold leading to eco-toxicological risks in basin.

A Greenhouse Study on Lead Uptake and Antioxidant Enzyme Activities in Vetiver Grass (Vetiveria zizanioides) as a Function of Lead Concentration and Soil Physico-Chemical Properties

NASA Astrophysics Data System (ADS)

Andra, S. P.; Datta, R.; Sarkar, D.; Saminathan, S. K.

2006-05-01

Lead (Pb) is a toxic non-essential metal that can cause permanent learning disabilities, retardation, mental and behavioral problems in children. Lead accumulation in soils result from weathering, chipping, scraping, sanding and sand blasting of housing structures constructed prior to 1978, bearing lead-based paint. The primary objective of this study is to develop a cost-effective, chelate-assisted phytoremediation for cleaning up lead contaminated soils. Soils are a unique environment of diverse physical and chemical characteristics that influence the extent of phytoavailable (labile) Pb forms. The success of phytoremediation strategy depends on the physiological/ biochemical tolerance of the plants to lipid peroxidation induced by Pb at sub-lethal levels. Oxidative challenge is alleviated by antioxidant compounds, but more importantly by the induction of antioxidant enzymes, which are crucial for scavenging reactive oxygen species (ROS) and terminating lipid peroxidation chain reaction. A column study was conducted in a temperature and humidity-controlled greenhouse setting to assess the extent of Pb phytoextraction and antioxidant response in a lead accumulator, vetiver grass (Vetiveria zizanioides). Treatments consisted of a randomized block arrangement of 4 soil types (Immokalee, Pahokee Muck, Tobosa, and Millhopper) and 3 soil Pb concentrations [normal - 400 mg/kg lead (following federal soil standards for lead), moderate - 800 mg/kg lead, and excessive - 1200 mg/kg lead] in 4 replicates. At the end of 6 months, selected columns were amended with a biodegradable chelating agent, ethylenediamene disuccinate (10 mmol/ kg EDDS), to mobilize Pb and enhance Pb uptake by vetiver. Total and exchangeable (labile) Pb were correlated with phytoextracted Pb, and levels of antioxidant enzymes viz., superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the root and shoot tissues of vetiver grass. Results indicate that Pb uptake and antioxidant enzymes activity in vetiver grass is dependent on soil physico-chemical properties and phytoavailable Pb concentrations.

Evaluation of the cadmium and lead phytoextraction by castor bean (Ricinus communis L.) in hydroponics

NASA Astrophysics Data System (ADS)

Niu, Z. X.; Sun, L. N.

2017-06-01

Phytoextraction has been considered as an innovative method to remove toxic metals from soil; higher biomass plants such as castor bean (Ricinus communis L.) have already been considered as a hyperaccumulating candidate. In the present study, castor bean was used to accumulate the cadmium and lead in hydroponic culture, and the root exudates and biomass changes were analyzed. Results demonstrated that ratios of aerial biomass/ root biomass (AW/RW) in treatments declined with concentrations of Cd or Pb. Optical density (OD) at 190 nm and 280 nm of root exudates observed in Cd and Pb treatments were lower than the control. In single Cd or Pb treatments, bioconcentration factors (BCF) of Cd or Pb increased with time and decreased with concentrations, the highest BCFs appeared in Cd5 (14.36) and Pb50 (6.48), respectively. Cd-BCF or Pb-BCF showed positive correlations with AW/RW ratios and OD values, and they were negative correlated with Cd and Pb concentration. Results in this study may supply useful information for phytoremediation of soil contaminated with cadmium and lead in situ.

Myco-phytoremediation of arsenic- and lead-contaminated soils by Helianthus annuus and wood rot fungi, Trichoderma sp. isolated from decayed wood.

PubMed

Govarthanan, M; Mythili, R; Selvankumar, T; Kamala-Kannan, S; Kim, H

2018-04-30

In the present study, Helianthus annuus grown in arsenic- (As) and lead- (Pb) contaminated soil were treated with plant-growth promoting fungi Trichoderma sp. MG isolated from decayed wood and assessed for their phytoremediation efficiency. The isolate MG exhibited a high tolerance to As (650mg/L) and Pb (500mg/L), and could remove > 70% of metals in aqueous solution with an initial concentration of 100mg/L each. In addition, the isolate MG was screened for plant-growth-promoting factors such as siderophores, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, indole acetic acid (IAA) synthesis, and phosphate solubilisation. Phytoremediation studies indicated that treatment of H. annuus with the isolate MG had the maximum metal-accumulation in shoots (As; 67%, Pb; 59%). Furthermore, a significant increase in the soil extracellular enzyme-activities was observed in myco-phytoremediated soils. The activities of phosphatase (35 U/g dry soil), dehydrogenase (41mg TPF/g soil), cellulase (37.2mg glucose/g/2h), urease (55.4mgN/g soil/2h), amylase (49.3mg glucose/g/2h) and invertase (45.3mg glucose/g/2h) significantly increased by 12%, 14%, 12%, 22%, 19% and 14% in As contaminated soil, respectively. Similarly, the activities of phosphatase (31.4U/g dry soil), dehydrogenase (39.3mg TPF/g soil), cellulase (37.1mg glucose/g/2h), urease (49.8mgN/g soil/2h), amylase (46.3mg glucose/g/2h), and invertase (42.1mg glucose/g/2h) significantly increased by 11%, 15%, 11%, 18%, 20% and 14% in Pb contaminated soil, respectively. Obtained results indicate that the isolate MG could be a potential strain for myco-phytoremediation of As and Pb contaminated soil. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of byproducts amended lead contaminated urban soils on carrot yield and lead uptake

USDA-ARS?s Scientific Manuscript database

Lead (Pb) has been used to produce a large number of materials and manufactured products. In areas with a history of lead paint use, high vehicular traffic and/or areas close to urban and industrial centers, atmospheric lead deposition may be very high. Consequently, a high deposition of lead in u...

Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability

PubMed Central

Li, Honghong; Liu, Yuting; Chen, Yanhui; Wang, Shanli; Wang, Mingkuang; Xie, Tuanhui; Wang, Guo

2016-01-01

This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar. Compared to the control treatment, amendment with 5% biochar resulted in 54 and 94% decreases in the acid soluble and CaCl2-extractable Pb, respectively, in soils containing rice plants at the maturity stage. The amount of Fe-plaque on root surfaces and the Pb concentrations of the Fe-plaque were also reduced in biochar amended soils. Furthermore, lead species in rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES), and although Pb-ferrihydrite complexes dominated Pb inventories, increasing amounts of organic complexes like Pb-pectins and Pb-cysteine were found in roots from the 5% biochar treatments. Such organic complexes might impede Pb translocation from root to shoot and subsequently reduce Pb accumulation in rice with biochar amendment. PMID:27530495

Lead and trace element levels in milk and blood of buffaloes (Bubalus bubalis) from Hyderabad, India.

PubMed

Shailaja, M; Reddy, Yathapu Srinivasa; Kalakumar, B D P; Brinda, S A; Manohar, Gottimukkula; Kumar, B Dinesh

2014-06-01

The presence of lead (Pb) in milk and its interaction with trace elements is a serious health concern. Present study is aimed at determining Pb and trace element (Fe, Zn and Mg) levels in milk and blood/serum samples of lactating buffaloes (Bubalus bubalis) living in a market-area (Group-A) and a dairy-experimental station (Group-B), Hyderabad, India. In addition, kidney and liver function tests were assessed. Fodder, milk and blood Pb levels were significantly (p < 0.01) higher in Group-B. Elevated Pb levels correlated positively with reduced Fe and Zn levels in both serum and milk. A significant (p < 0.01) positive correlation between blood Pb and milk Pb levels was observed. Kidney and liver function markers were significantly higher in Group-B buffaloes. The results suggest that contaminated fodder might be one of the responsible factors for elevated Pb levels. In addition, lower levels of Fe and Zn might have led to bioaccumulation of Pb in blood and milk.

Effects of lead contamination on soil enzymatic activities, microbial biomass, and rice physiological indices in soil-lead-rice (Oryza sativa L.) system.

PubMed

Zeng, Lu S; Liao, Min; Chen, Cheng L; Huang, Chang Y

2007-05-01

The effect of lead (Pb) treatment on the soil enzymatic activities, soil microbial biomass, rice physiological indices and rice biomass were studied in a greenhouse pot experiment. Six levels of Pb viz. 0(CK), 100, 300, 500, 700, 900 mg/kg soil were applied in two types of paddy soils. The results showed that Pb treatment had a stimulating effect on soil enzymatic activities and microbial biomass carbon (Cmic) at low concentration and an inhibitory influence at higher concentration. The degree of influence on enzymatic activities and Cmic by Pb was related to the clay and organic matter contents of the soils. When the Pb treatment was raised to the level of 500 mg/kg, ecological risk appeared both to soil microorganisms and plants. The results also revealed a consistent trend of increased chlorophyll contents and rice biomass initially, maximum at a certain Pb treatment, and then decreased gradually with the increase in Pb concentration. Pb was effective in inducing proline accumulation and its toxicity causes oxidative stress in rice plants. Therefore, it was concluded that soil enzymatic activities, Cmic and rice physiological indices, could be sensitive indicators to reflect environmental stress in soil-lead-rice system.

Cigarette smoking and lead levels in occupationally exposed lead workers

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

Brown, C.P.; Spivey, G.H.; Valentine, J.L.

One hundred eleven workers at a secondary Pb smelter were surveyed to determine smoking and personal hygiene habits. Fifty-three percent of the smokers had blood Pb levels in excess of 60 ..mu..g/dl, compared to 31% of nonsmokers (p = 0.02). Among smokers, 66% of heavy smokers (greater than or equal to 1 pack a day) had blood Pb levels over 60 ..mu..g/dl, compared to 39% of the light smokers (p = O.05). Those who kept their cigarettes on their person had a higher proportion of blood Pb greater than 60 ..mu..g/dl than workers who kept their cigarettes elsewhere (63 vsmore » 36%, respectively; p = 0.08). The difference in blood Pb levels between smokers and nonsmokers may be due in part to direct environmental contamination of cigarettes or impaired lung clearance mechanisms, and could be important in workers with already elevated blood Pb levels.« less

Chelant-aided enhancement of lead mobilization in residential soils.

PubMed

Sarkar, Dibyendu; Andra, Syam S; Saminathan, Sumathi K M; Datta, Rupali

2008-12-01

Chelation of metals is an important factor in enhancing solubility and hence, availability to plants to promote phytoremediation. We compared the effects of two chelants, namely, ethylenediaminetetraacetic acid (EDTA) and ethylenediaminedisuccinic acid (EDDS) in enhancing mobilized lead (Pb) in Pb-based paint contaminated residential soils collected from San Antonio, Texas and Baltimore, Maryland. Batch incubation studies were performed to investigate the effectiveness of the two chelants in enhancing mobilized Pb, at various concentrations and treatment durations. Over a period of 1 month, the mobilized Pb pool in the San Antonio study soils increased from 52 mg kg(-1) to 287 and 114 mg kg(-1) in the presence of 15 mM kg(-1) EDTA and EDDS, respectively. Stepwise linear regression analysis demonstrated that pH and organic matter content significantly affected the mobilized Pb fraction. The regression models explained a large percentage, from 83 to 99%, of the total variation in mobilized Pb concentrations.

Effect of peanut shell and wheat straw biochar on the availability of Cd and Pb in a soil-rice (Oryza sativa L.) system.

PubMed

Xu, Chao; Chen, Hao-Xiang; Xiang, Qian; Zhu, Han-Hua; Wang, Shuai; Zhu, Qi-Hong; Huang, Dao-You; Zhang, Yang-Zhu

2018-01-01

Soil amendments, such as biochar, have been used to enhance the immobilization of heavy metals in contaminated soil. A pot experiment was conducted to immobilize the available cadmium (Cd) and lead (Pb) in soil using peanut shell biochar (PBC) and wheat straw biochar (WBC), and to observe the accumulation of these heavy metals in rice (Oryza sativa L.). The application of PBC and WBC led to significantly higher pH, soil organic carbon (SOC), and cation exchange capacity (CEC) in paddy soil, while the content of MgCl 2 -extractable Cd and Pb was lower than that of untreated soil. MgCl 2 -extractable Cd and Pb showed significant negative correlations with pH, SOC, and CEC (p < 0.01). The application of 5% biochar to contaminated paddy soil led to reductions of 40.4-45.7 and 68.6-79.0%, respectively, in the content of MgCl 2 -extractable Cd and Pb. PBC more effectively immobilized Cd and Pb than WBC. Sequential chemical extractions revealed that biochar induced the transformation of the acid-soluble fraction of Cd to oxidizable and residual fractions, and the acid-soluble fraction of Pb to reducible and residual fractions. PBC and WBC clearly inhibited the uptake and accumulation of Cd and Pb in rice plants. Specially, when compared to the corresponding concentrations in rice grown in control soils, 5% PBC addition lowered Cd and Pb concentrations in grains by 22.9 and 12.2%, respectively, while WBC addition lowered them by 29.1 and 15.0%, respectively. Compared to Pb content, Cd content was reduced to a greater extent in grain by PBC and WBC. These results suggest that biochar application is effective for immobilizing Cd and Pb in contaminated paddy soil, and reduces their bioavailability in rice. Biochar could be used as a soil amendment for the remediation of soils contaminated with heavy metals.

Apatite ore mine tailings as an amendment for remediation of a lead-contaminated shooting range soil.

PubMed

Venäläinen, Salla H

2011-10-01

This study investigated the use of tailings from apatite ore beneficiation in the remediation of a heavily contaminated shooting range soil. The tailings originating in Siilinjärvi carbonatite complex, Finland, consist of apatite residues accompanied by phlogopite and calcite. In a pot experiment, organic top layer of a boreal forest soil predisposed to pellet-derived lead (Pb) was amended with tailings of various particle-sizes (Ø>0.2mm, Ø<0.2mm and unsieved material) differing in their mineralogical composition. After 9-, 10-, 14- and 21-month incubation, the samples were monitored for tailings-induced changes in the different Pb pools by means of sequential fractionation. Following the incubation, the samples were extracted with water and the extracts were analyzed for Pb species distribution by means of a cation exchange resin. The results revealed that Pb was continuously released from the shotgun pellet fragments due to weathering. However, the apatite and calcite compartments in the tailings counteracted the mobility of the released Pb through the formation of sparingly soluble fluorpyromorphite and cerussite. Furthermore, the tailings efficiently reduced the bioavailability of Pb by transferring it from the water-soluble and exchangeable pools into the organic one. The material also increased the proportion of the less toxic non-cationic Pb to the total dissolved Pb from the initial level of 5% to 9-12%. The results suggest that the tailings-induced stabilization of Pb may be an environmentally sound remediation technique at polluted sites. Copyright © 2011 Elsevier B.V. All rights reserved.

Bioavailability and risk assessment of potentially toxic elements in garden edible vegetables and soils around a highly contaminated former mining area in Germany.

PubMed

Antoniadis, Vasileios; Shaheen, Sabry M; Boersch, Judith; Frohne, Tina; Du Laing, Gijs; Rinklebe, Jörg

2017-01-15

Although soil contamination by potentially toxic elements (PTEs) in Europe has a history of many centuries, related problems are often considered as having been dealt with due to the enforcement of tight legislations. However, there are many unsolved issues. We aimed to assess PTE levels in highly contaminated soils and in garden edible vegetables using human health risk indices in order to evaluate the availability and mobilization of arsenic (As), copper (Cu), manganese (Mn), mercury (Hg), lead (Pb), and zinc (Zn). In four gardens in Germany, situated on, or in the vicinity of, a mine dump area, we planted beans (Phaseolus vulgaris ssp. nanus), carrots (Daucus sativus) and lettuce (Lactuca sativa ssp. capitata). We examined soil-to-plant mobilization of elements using transfer coefficient (TC), as well as soil contamination using contamination factor (CF), enrichment factor (EF), and bioaccumulation index (I geo ). In addition, we tested two human health risk assessment indices: Soil-induced hazard quotient (HQ S ) (representing the "direct soil ingestion" pathway), and vegetable-induced hazard quotient (HQ V ) (representing the "vegetable intake" pathway). The studied elements were highly elevated in the soils. The values in garden 2 were especially high (e.g., Pb: 13789.0 and Hg: 36.8 mg kg -1 ) and largely exceeded the reported regulation limits of 50 (for As), 40 (Cu), 400 (Pb), 150 (Zn), and 5 (Hg) mg kg -1 . Similarly, element concentrations were very high in the grown vegetables. The indices of CF, EF and I geo were enhanced even to levels that are rarely reported in the literature. Specifically, garden 2 indicated severe contamination due to multi-element deposition. The contribution of each PTE to the total of measured HQ S revealed that Pb was the single most important element causing health risk (contributing up to 77% to total HQ S ). Lead also posed the highest risk concerning vegetable consumption, contributing up to 77% to total HQ V . The presence of lead in both cases was followed by that of As, Mn and Hg. We conclude that in multi-element contamination cases, along with high-toxicity elements (here, Pb, As and Hg) other elements may also be responsible for increasing human health risks (i.e., Mn), due to the possibility of adverse synergism of the PTEs. Copyright © 2016. Published by Elsevier Ltd.

Remediation of lead-contaminated water by geological fluorapatite and fungus Penicillium oxalicum.

PubMed

Tian, Da; Wang, Wenchao; Su, Mu; Zheng, Junyi; Wu, Yuanyi; Wang, Shimei; Li, Zhen; Hu, Shuijin

2018-05-16

Phosphate-solubilizing fungi (PSF) can secrete large amounts of organic acids. In this study, the application of the fungus Penicillium oxalicum and geological fluorapatite (FAp) to lead immobilization was investigated. The formation and morphology of the lead-related minerals were analyzed by ATR-IR, XRD, Raman, and SEM. The quantity of organic acids secreted by P. oxalicum reached the maximum on the fourth day, which elevated soluble P concentrations from 0.4 to 108 mg/L in water. The secreted oxalic acid dominates the acidity in solution. P. oxalicum can survive in the solution with Pb concentration of ~ 1700 mg/L. In addition, it was shown that ~ 98% lead cations were removed while the fungus was cultured with Pb (~ 1700 mg/L) and FAp. The mechanism is that the released P from FAp (enhanced by organic acids) can react with Pb 2+ to form the stable pyromorphite mineral [Pb 5 (PO 4 ) 3 F]. The precipitation of lead oxalate also contributes to Pb immobilization. However, lead oxalate is more soluble due to its relatively high solubility. P. oxalicum has a higher rate of organic acid secretion compared with other typical PSF, e.g., Aspergillus niger. This study sheds light on bright future of applying P. oxalicum in Pb remediation.

Omaha Soil Mixing Study: Redistribution of Lead in Remediated Residential Soils Due to Excavation or Homeowner Disturbance.

EPA Science Inventory

Urban soils within the Omaha Lead Superfund Site have been contaminated with lead (Pb) from atmospheric deposition of particulate materials from lead smelting and recycling activities. In May of 2009 the Final Record of Decision stated that any residential soil exceeding the pre...

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

PubMed

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

2006-05-01

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

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

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

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

2006-05-15

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

Advances in Assessing Bioavailability of Metal(loid)s in Contaminated Soils

USDA-ARS?s Scientific Manuscript database

The term bioavailability has many different meanings across various disciplines of toxicology and pharmacology. Often bioavailability is concerned with human health aspects such in the case of lead (Pb) ingestion by children. However, some of the most contaminated sites are found in non-public acc...

Elevated CO2 affects secondary metabolites in Robinia pseudoacacia L. seedlings in Cd- and Pb-contaminated soils.

PubMed

Jia, Xia; Zhao, Yonghua; Liu, Tuo; Huang, Shuping

2016-10-01

Secondary metabolites play important roles in plant interactions with the environment. The co-occurrence of heavy metal contamination of soils and rising atmospheric CO2 has important effects on plant. It is important to explore the ways in which production of plant secondary metabolites is affected by heavy metals under elevated atmospheric CO2. We examined the effects of elevated CO2 on secondary metabolite contents in Robinia pseudoacacia seedlings grown in Cd- and lead (Pb)-contaminated soils. The increase in secondary metabolites was greater under Cd + Pb exposure than under exposure to individual metals regardless of elevated CO2 with the exception of condensed tannins in leaves and total alkaloids in stems. Except for phenolic compounds and condensed tannins, elevated CO2 was associated with increased secondary metabolite contents in leaves and stems of plants exposed to Cd, Pb, and Cd + Pb compared to plants exposed to ambient CO2 + metals. Changes in saponins in leaves and alkaloids in stems were greater than changes in the other secondary metabolites. Significant interactive effects of CO2, Cd, and Pb on secondary metabolites were observed. Saponins in leaves and alkaloids in stems were more sensitive than other secondary metabolites to elevated CO2 + Cd + Pb. Elevated CO2 could modulate plant protection and defense mechanisms in R. pseudoacacia seedlings exposed to heavy metals by altering the production of secondary metabolites. The increased Cd and Pb uptake under elevated CO2 suggested that R. pseudoacacia may be used in the phytoremediation of heavy metal-contaminated soils under global environmental scenarios. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Combined Effects of Arbuscular Mycorrhizal Fungi (AMF) and Lead (Pb) Stress on Pb Accumulation, Plant Growth Parameters, Photosynthesis, and Antioxidant Enzymes in Robinia pseudoacacia L.

PubMed Central

Liang, Yan; Ghosh, Amit; Chen, Jie; Tang, Ming

2015-01-01

Arbuscular mycorrhizal fungi (AMF) are considered as a potential biotechnological tool for improving phytostabilization efficiency and plant tolerance to heavy metal-contaminated soils. However, the mechanisms through which AMF help to alleviate metal toxicity in plants are still poorly understood. A greenhouse experiment was conducted to evaluate the effects of two AMF species (Funneliformis mosseae and Rhizophagus intraradices) on the growth, Pb accumulation, photosynthesis and antioxidant enzyme activities of a leguminous tree (Robinia pseudoacacia L.) at Pb addition levels of 0, 500, 1000 and 2000 mg kg-1 soil. AMF symbiosis decreased Pb concentrations in the leaves and promoted the accumulation of biomass as well as photosynthetic pigment contents. Mycorrhizal plants had higher gas exchange capacity, non-photochemistry efficiency, and photochemistry efficiency compared with non-mycorrhizal plants. The enzymatic activities of superoxide dismutase (SOD), ascorbate peroxidases (APX) and glutathione peroxidase (GPX) were enhanced, and hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents were reduced in mycorrhizal plants. These findings suggested that AMF symbiosis could protect plants by alleviating cellular oxidative damage in response to Pb stress. Furthermore, mycorrhizal dependency on plants increased with increasing Pb stress levels, indicating that AMF inoculation likely played a more important role in plant Pb tolerance in heavily contaminated soils. Overall, both F. mosseae and R. intraradices were able to maintain efficient symbiosis with R. pseudoacacia in Pb polluted soils. AMF symbiosis can improve photosynthesis and reactive oxygen species (ROS) scavenging capabilities and decrease Pb concentrations in leaves to alleviate Pb toxicity in R. pseudoacacia. Our results suggest that the application of the two AMF species associated with R. pseudoacacia could be a promising strategy for enhancing the phytostabilization efficiency of Pb contaminated soils. PMID:26698576

Resuspension of soil as a source of airborne lead near industrial facilities and highways.

PubMed

Young, Thomas M; Heeraman, Deo A; Sirin, Gorkem; Ashbaugh, Lowell L

2002-06-01

Geologic materials are an important source of airborne particulate matter less than 10 microm aerodynamic diameter (PM10), but the contribution of contaminated soil to concentrations of Pb and other trace elements in air has not been documented. To examine the potential significance of this mechanism, surface soil samples with a range of bulk soil Pb concentrations were obtained near five industrial facilities and along roadsides and were resuspended in a specially designed laboratory chamber. The concentration of Pb and other trace elements was measured in the bulk soil, in soil size fractions, and in PM10 generated during resuspension of soils and fractions. Average yields of PM10 from dry soils ranged from 0.169 to 0.869 mg of PM10/g of soil. Yields declined approximately linearly with increasing geometric mean particle size of the bulk soil. The resulting PM10 had average Pb concentrations as high as 2283 mg/kg for samples from a secondary Pb smelter. Pb was enriched in PM10 by 5.36-88.7 times as compared with uncontaminated California soils. Total production of PM10 bound Pb from the soil samples varied between 0.012 and 1.2 mg of Pb/kg of bulk soil. During a relatively large erosion event, a contaminated site might contribute approximately 300 ng/m3 of PM10-bound Pb to air. Contribution of soil from contaminated sites to airborne element balances thus deserves consideration when constructing receptor models for source apportionment or attempting to control airborne Pb emissions.

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

PubMed Central

2017-01-01

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

[Evaluation of phosphate-containing amendments on remediation effect and influential factors in a lead/zinc mining tailings contaminated soil using TCLP and forms].

PubMed

Chen, Jian-Jun; Yu, Tian-Ming; Wang, Bi-Ling; Xie, Zheng-Miao

2010-01-01

A pot experiment was conducted to evaluate the effects of phosphate-containing (P) amendments on the toxicity and bioavailability of Pb and Zn in a soil contaminated by mining tailings using toxicity characteristic leaching procedure (TCLP) and water soluble, exchangeable leaching procedures in order to find out the appropriate P application rates to reduce the soil TCLP extractable Pb to below the USA EPA's regulatory limit levels. The results showed that TCLP extractable Pb concentrations were significantly decreased by up to 93.3% for MPP treatments and up to 68.5% for SSP treatments after P application. The dose required to reduce leachable Pb below the EPA's regulatory limit level was found to be around the molar ratio of v(P/Pb) = 0.6 for MPP and 1.8 for SSP. It was also found both MPP and SSP could reduce the exchangeable Pb and Zn concentrations that all bio-available Zn forms including water soluble, exchangeable, and TCLP extractable forms in soil were significantly and negatively correlated to soil pH values, indicating that the content of Zn in the soil was mostly controlled by soil pH value even after P application. These results suggest that P as MPP and SSP could successfully decrease the toxicity and bioavailability of Pb and Zn in the contaminated soil.

Relationship of diets and environmental contaminants in wintering bald eagles. [Haliaeetus leucocephalus

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

Frenzel, R.W.; Anthony, R.G.

1989-07-01

We investigated the relationship between diets and potential hazards in contaminants of wintering bald eagles (Haliaeetus leucocephalus) in the Klamath Basin of northern California and southern Oregon. We studied diets by identifying remains of 913 prey items found at perches, examining 341 castings collected from communal night roots, and observing foraging eagles. We determined residues of organochlorine compounds, lead (Pb), and mercury (Hg) in bald eagles and their prey by analyzing eagle blood samples and carcasses and 8 major prey species. Bald eagles fed largely on waterfowl by scavenging cholera-killed ducks and geese and on microtine rodents during mid- tomore » late winter. Residues of organochlorine pesticides and Hg in prey were low, and polychlorinated biphenyls (PCB's) were detected in low concentrations in 9% of prey samples. Means Pb concentrations in prey ranged from 0.15 to 4.79 ppm. Mercury was detected in all eagle blood samples, and Pb was detected in 41% of the bald eagle blood samples. Mean Pb concentration in livers of dead eagles was 2.09 ppm and ranged as high as 27 ppm in an eagle that died of Pb poisoning. Prey of the eagles were relatively free of contaminants with the possible exception of embedded Pb shot in waterfowl, which may present a potential for Pb poisoning of eagles.« less

Heart function in magnetic resonance imaging and the mesenteric artery reactivity in rats receiving lead-contaminated drinking water.

PubMed

Skoczynska, A; Skórka, T; Wojakowska, A; Nowacki, D; Turczyn, B; Poręba, R; Tyrankiewicz, U; Byk, K; Szuba, A

2014-05-01

The aim of this study was to evaluate the effect of lead (Pb)-contaminated drinking water on magnetic resonance imaging (MRI)-estimated cardiac function, vascular reactivity, and serum lipids in rats. For 3 months, male Wistar rats, aged 4-6 weeks, were given drinking water with the addition of lead acetate at a concentration of 100 ppm Pb (10 rats) or water free from Pb (8 control rats). The cardiac MRI was performed at rest and under β-adrenergic stimulation on a 4.7 T scanner using electrocardiogram-triggered gradient echo (FLASH) cine sequence. After 1-2 weeks of the MRI test, experiments were performed ex vivo. After stabilization of perfusion pressure (PP), norepinephrine at doses from 0.01 to 5.0 μg was dissolved in Krebs solution, injected in a volume of 100 μl, and next infused at a concentration of 0.5 μg/ml into the isolated mesenteric artery. In this manner, preconstricted mesenteric bed was used to determine PP changes induced by acetylcholine, given at doses from 0.05 to 5.0 μg, before and during the infusion of nitric oxide synthase inhibitor (1.0 μg/ml). At the end, dobutamine (5 mg), followed by potassium chloride (10.5 mg), was injected. Lipid levels were determined enzymatically, blood Pb level was measured by the atomic absorption spectrophotometer. This study showed that Pb impairs the left ventricular systolic and diastolic function. Pb-induced changes in response to resistance of vessels to vasoactive agents may be secondary to the reduced left ventricular ejection fraction. The high-density lipoprotein subfraction 2 (HDL2) is involved in the cardiovascular effect of Pb.

Effects of Pb Smelting on the Soil Bacterial Community near a Secondary Lead Plant.

PubMed

Luo, Zhanbin; Ma, Jing; Chen, Fu; Li, Xiaoxiao; Zhang, Shaoliang

2018-05-20

Secondary lead smelting is a widespread industrial activity which has exacerbated Pb or Cd contamination of soil and water across the world. Soil physicochemical properties, soil enzyme activities, heavy metal concentrations, and bacterial diversity near a secondary lead plant in Xuzhou, China were examined in this study. The results showed that secondary lead smelting activities influenced nearby soils. Soil acidification decreased one order of magnitude, with a mean value of 7.3. Soil organic matter also showed a downward trend, while potassium and nitrogen appeared to accumulate. Soil urease and protease activity increased in samples with greater heavy metal pollution, but overall the soil microbial biodiversity decreased. Soil heavy metal concentration-especially Pb and Cd-greatly exceeded the concentrations of Chinese Environmental Quality Standard for Soils (GB 15618-1995). Some environmental factors-such as pH, organic matter, enzyme activity, and the concentration of heavy metals-significantly affected bacterial diversity: compared with the control site, the Chao1 estimator decreased about 50%, while the Shannon diversity index dropped approximately 20%. Moreover, some genera have significant relationships with heavy metal concentration-such as Ramlibacter with Zn and Steroidobacter with Cd-which might act as bio-indicators for soil remediation. These results will provide a new insight in the future for reclaiming soil contaminants caused by secondary lead smelting.

Clean galena, contaminated lead, and soft errors in memory chips

NASA Astrophysics Data System (ADS)

Lykken, G. I.; Hustoft, J.; Ziegler, B.; Momcilovic, B.

2000-10-01

Lead (Pb) disks were exposed to a radon (Rn)-rich atmosphere and surface alpha particle emissions were detected over time. Cumulative 210Po alpha emission increased nearly linearly with time. Conversely, cumulative emission for each of 218Po and 214Po was constant after one and two hours, respectively. Processing of radiation-free Pb ore (galena) in inert atmospheres was compared with processing in ambient air. Galena processed within a flux heated in a graphite crucible while exposed to an inert atmosphere, resulted in lead contaminated with 210Po (Trial 1). A glove box was next used to prepare a baseline radiation-free flux sample in an alumina crucible that was heated in an oven with an inert atmosphere (Trials 2 and 3). Ambient air was thereafter introduced, in place of the inert atmosphere, to the radiation-free flux mixture during processing (Trial 4). Ambient air introduced Rn and its progeny (RAD) into the flux during processing so that the processed Pb contained Po isotopes. A typical coke used in lead smelting also emitted numerous alpha particles. We postulate that alpha particles from tin/lead solder bumps, a cause of computer chip memory soft errors, may originate from Rn and RAD in the ambient air and/or coke used as a reducing agent in the standard galena smelting procedure.

Legacy lead arsenate soil contamination at childcare centers in the Yakima Valley, Central Washington, USA.

PubMed

Durkee, Jenna; Bartrem, Casey; Möller, Gregory

2017-02-01

From the early 1900s to the 1950s, Yakima Valley orchards were commonly treated with lead arsenate (LA) insecticides. Lead (Pb) and arsenic (As) soil contamination has been identified on former orchard lands throughout Central Washington and pose a threat to human health and the environment. The levels of Pb and As in soil and interior dust at participating childcare centers in the Upper Yakima Valley (Yakima County), Washington were sampled to explore exposure potential for young children. Childcare center soils were collected from two soil depths, homogenized, and analyzed in bulk by a field-portable X-ray fluorescence spectrometer (XRF). Interior dust wipes samples were collected from at least two locations in each facility. All soil samples >250 mg/kg Pb and/or >20 As mg/kg were sieved to 250 μm, tested by XRF a second time, and analyzed via acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) analysis. Bulk and sieved XRF results, as well as ICP-MS to XRF results were strongly correlated. Maximum Pb and As XRF results indicated that 4 (21%) and 8 (42%) of the 19 childcare centers surveyed exceeded the regulatory standard for Pb and As, respectively. Historic land use was significantly associated with elevated Pb and As levels. Interior dust loadings were below United States Environmental Protection Agency (EPA) guidelines. Childcare centers are areas of intensive use for children and when coupled with potential residential exposure in their homes, the total daily exposure is a potential hazard to children. Copyright © 2016 Elsevier Ltd. All rights reserved.

210Pb dating of sediments in a heavily contaminated drainage channel to the La Plata estuary in Buenos Aires, Argentina.

PubMed

Di Gregorio, D E; Fernández Niello, J O; Huck, H; Somacal, H; Curutchet, G

2007-01-01

Concentrations of (210)Pb and (137)Cs in sediment samples collected from two cores at a drainage channel to the La Plata river estuary in Buenos Aires, Argentina, were measured using ultralow-background detection systems. The (210)Pb data were used to determine the rate of sediment accumulation of the sites. These results were correlated with some heavy metal (chromium and lead) concentrations of the samples in an attempt to characterize the historical input of contaminants due to the industrial development, which has taken place in this area over the last century. The (137)Cs measurements demonstrate that cesium dating is not adequate in regions of the southern hemisphere.

Effects of lead contamination on soil microbial activity and rice physiological indices in soil-Pb-rice (Oryza sativa L.) system.

PubMed

Zeng, Lu-Sheng; Liao, Min; Chen, Cheng-Li; Huang, Chang-Yong

2006-10-01

The effect of lead (Pb) treatment on the soil microbial activities (soil microbial biomass and soil basal respiration) and rice physiological indices were studied by greenhouse pot experiment. Pb was applied as lead acetate at six different levels in two different paddy soils, namely 0 (control), 100, 300, 500, 700, 900 mg kg-1 soil. The results showed that the application of Pb at lower level (<300 mg kg-1) as lead acetate resulted in a slight increase in soil microbial activities compared with the control, and had an inhibitory influence at high concentration (>500 mg Pb kg-1 soil), which might be the critical concentration of Pb causing a significant decline in the soil microbial activities. However, the degree of influence on soil microbial activities by Pb was related to the clay and organic matter contents of the soils. On the other hand, when the level of Pb treatments increased to 500 mg kg-1, there was ecological risk for both soil microbial activities and plants. The results also revealed that there was a consistent trend that the chlorophyll contents increased initially, and then decreased gradually with increase in Pb concentration. Pb was effective in inducing proline accumulation and its toxicity causes oxidative stress in rice plants. In a word, soil microbial activities and rice physiological indices, therefore, may be sensitive indicators reflecting environmental stress in soil-Pb-rice system.

Can the soil fauna of boreal forests recover from lead-derived stress in a shooting range area?

PubMed

Selonen, Salla; Liiri, Mira; Setälä, Heikki

2014-04-01

The responses of soil faunal communities to lead (Pb) contamination in a shooting range area and the recovery of these fauna after range abandonment were studied by comparing the communities at an active shotgun shooting range, an abandoned shooting range, and a control site, locating in the same forest. Despite the similar overall Pb pellet load at the shooting ranges, reaching up to 4 kg m(-2), Pb concentrations in the top soil of the abandoned range has decreased due to the accumulation of detritus on the soil surface. As a consequence, soil animal communities were shown to recover from Pb-related disturbances by utilizing the less contaminated soil layer. Microarthropods showed the clearest signs of recovery, their numbers and community composition being close to those detected at the control site. However, in the deepest organic soil layer, the negative effects of Pb were more pronounced at the abandoned than at the active shooting range, which was detected as altered microarthropod and nematode community structures, reduced abundances of several microarthropod taxa, and the total absence of enchytraeid worms. Thus, although the accumulation of fresh litter on soil surface can promote the recovery of decomposer communities in the top soil, the gradual release of Pb from corroding pellets may pose a long-lasting risk for decomposer taxa deeper in the soil.

Quantifying the contribution of airborne lead (Pb) to surface waters in northeastern Oklahoma

NASA Astrophysics Data System (ADS)

Li, J. J.; McDonald, J.; Curtis, H.

2017-12-01

The northeastern Oklahoma, home to a number of Native American Tribes, is part of the well-known Tri-State Mining District (TSMD). One hundred years of mining production in this area has left numerous, large chat piles on the surrounding environment, directly affecting the town of Picher and many other tribe communities. Byproducts of the mining, including lead (Pb)-contain dust have been transported to the atmosphere and seeped into groundwater, lakes, ponds and rivers. Due to this contamination, many children in the area have elevated levels of Pb in their bodies. Despite a substantial number of studies and efforts on the restoration of heavy metal contamination in this area (e.g. The Tar Creek Superfund Site, EPA), no studies have attempted to distinguish the contributions of different sources, particularly from the atmospheric deposition, of heavy metals to the aquatic environment. In this study, we analyzed the atmospheric deposition of Pb from 4 sites located close to the chat piles for the period of 2010 to 2016. Our preliminary analysis showed that atmospheric Pb has a strong seasonal pattern with two peak times in early spring and late fall, which largely correspond with the dry periods in the this area. Atmospheric concentrations of Pb monitored at these sites frequently exceeded 0.15 μg/m3, the National Ambient Air Quality Standards (NAAQS) standard for ambient air Pb, and was generally 10 times higher than atmospheric Pb monitored in Tulsa, OK, a major metropolitan area 150 km southwest of the monitoring sites. With the known Pb flux to the sediments of the water bodies, we estimated that the contribution of Pb from the atmospheric deposition to the surface waters is up to 25%, depending on the distance of the water bodies to concentrated distribution of the chat piles.

Occurrence of contaminant accumulation in lead pipe scales from domestic drinking-water distribution systems.

PubMed

Schock, Michael R; Hyland, Robert N; Welch, Meghan M

2008-06-15

Previously, contaminants, such as AI, As, and Ra, have been shown to accumulate in drinking-water distribution system solids. Accumulated contaminants could be periodically released back into the water supply causing elevated levels at consumers taps, going undetected by most current regulatory monitoring practices and consequently constituting a hidden risk. The objective of this study was to determine the occurrence of over 40 major scale constituents, regulated metals, and other potential metallic inorganic contaminants in drinking-water distribution system Pb (lead) or Pb-lined service lines. The primary method of analysis was inductively coupled plasma-atomic emission spectroscopy, following complete decomposition of scale material. Contaminants and scale constituents were categorized by their average concentrations, and many metals of potential health concern were found to occur at levels sufficient to result in elevated levels at the consumer's taps if they were to be mobilized. The data indicate distinctly nonconservative behavior for many inorganic contaminants in drinking-water distribution systems. This finding suggests an imminent need for further research into the transport and fate of contaminants throughout drinking-water distribution system pipes, as well as a re-evaluation of monitoring protocols in order to more accurately determine the scope and levels of potential consumer exposure.

Hydrolytic and ligninolytic enzyme activities in the Pb contaminated soil inoculated with litter-decomposing fungi.

PubMed

Kähkönen, Mika A; Lankinen, Pauliina; Hatakka, Annele

2008-06-01

The impact of Pb contamination was tested to five hydrolytic (beta-glucosidase, beta-xylosidase, beta-cellobiosidase, alpha-glucosidase and sulphatase) and two ligninolytic (manganese peroxidase, MnP and laccase) enzyme activities in the humus layer in the forest soil. The ability of eight selected litter-degrading fungi to grow and produce extracellular enzymes in the heavily Pb (40 g Pb of kg ww soil(-1)) contaminated and non-contaminated soil in the non-sterile conditions was also studied. The Pb content in the test soil was close to that of the shooting range at Hälvälä (37 g Pb of kg ww soil(-1)) in Southern Finland. The fungi were Agaricus bisporus, Agrocybe praecox, Gymnopus peronatus, Gymnopilus sapineus, Mycena galericulata, Gymnopilus luteofolius, Stropharia aeruginosa and Stropharia rugosoannulata. The Pb contamination (40 g Pb of kg ww soil(-1)) was deleterious to all five studied hydrolytic enzyme activities after five weeks of incubation. All five hydrolytic enzyme activities were significantly higher in the soil than in the extract of the soil indicating that a considerable part of enzymes were particle bound in the soils. Hydrolytic enzyme activities were higher in the non-contaminated soil than in the Pb contaminated soil. Fungal inocula increased the hydrolytic enzyme activities beta-cellobiosidase and beta-glucosidase in non-contaminated soils. All five hydrolytic enzyme activities were similar with fungi and without fungi in the Pb contaminated soil. This was in line that Pb contamination (40 g Pb of kg ww soil(-1)) depressed the growth of all fungi compared to those grown without Pb in the soil. Laccase and MnP activities were low in both Pb contaminated and non-contaminated soil cultures. MnP activities were higher in soil cultures containing Pb than without Pb. Our results showed that Pb in the shooting ranges decreased fungal growth and microbial functioning in the soil.

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture.

PubMed

Zhi-xin, Niu; Sun, Li-na; Sun, Tie-heng; Li, Yu-shuang; Wang, Hong

2007-01-01

Soil contaminated with heavy metals cadmium (Cd) and lead (Pb) is hard to be remediated. Phytoremediation may be a feasible method to remove toxic metals from soil, but there are few suitable plants which can hyperaccumulate metals. In this study, Cd and Pb accumulation by four plants including sunflower (Helianthus annuus L.), mustard (Brassica juncea L.), alfalfa (Medicago sativa L.), ricinus (Ricinus communis L.) in hydroponic cultures was compared. Results showed that these plants could phytoextract heavy metals, the ability of accumulation differed with species, concentrations and categories of heavy metals. Values of BCF (bioconcentration factor) and TF (translocation factor) indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals. Changes on the biomass of plants, pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures. Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals, such as pH and Eh regulations, and so forth.

Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

PubMed

Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

2015-04-01

Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing.

A 59-year sedimentary record of metal pollution in the sediment core from the Huaihe River, Huainan, Anhui, China.

PubMed

Wang, Jie; Liu, Guijian; Zhang, Jiamei; Liu, Houqi; Lam, Paul K S

2016-12-01

An approximately 59-year (1955-2014) sedimentary record of metal elements (Cu, Pb, Zn, Ni, Co, Mn, and Fe) in a sediment core, collected from the Huaihe River, Huainan City, Anhui Province, China, was reconstructed by using 210 Pb geochronology. Copper, Zn, Ni, Co, and Mn evaluated by enrichment factor (EF) indicated minor contamination due to water pollution accidents of the Huaihe River that occurred in 1990s and 2004. Lead presented the most severe pollution among the metals studied, especially during 1957-1974. The use of leaded petrol and atmospheric deposition of coal combustion flue gases could have contributed to Pb contamination. In spite of the general good quality (mean sediment pollution index (SPI) 35.69) of the sediment core evaluated by SPI based on the principal component analysis, worse sediment qualities in the upper section (<6 cm, 2004) were still observed, suggesting intensive human activities causing the increasing concentrations of metals in recent decades.

Lead Contamination and Source Characterization in Soils Around a Lead-Zinc Smelting Plant in a Near-Urban Environment in Baoji, China.

PubMed

Deng, Wenbo; Li, Xuxiang; An, Zhisheng; Yang, Liu

2016-11-01

Economic reforms in China since 1978 have promoted nationwide socioeconomic advancement but led to a considerable amount of environmental pollution. The distribution and sources of Pb in a typical peri-urban industrial part of Baoji, China, were assessed by determining the Pb contents and isotopic compositions in 52 topsoil samples from the study area. The topsoil samples were polluted averagely with 40.88 mg Pb kg -1 , was 1.86 times higher than the Pb content of local background soil (22.04 mg kg -1 ). Pb isotopic compositions were determined by analyzing samples prepared using total digestion and acid extraction methods. Radiogenic isotopes contributed more to the Pb concentrations in the acid extracts than in the total digests. This was shown by the 207/206 Pb and 208/206 Pb ratios, which were 0.845-0.88 and 2.088-2.128, respectively, in the acid extracts and 0.841-0.875 and 2.086-2.125, respectively, in the total digests. This indicates that anthropogenic sources of Pb could be identified more sensitively in acid extracts than in total digests. The Pb isotope ratios showed that burning coal and smelting ore are the predominant anthropogenic sources of Pb in the study area, i.e., a lead-zinc smelter and a coking plant are major sources of Pb in the study area.

Mechanisms of biochar assisted immobilization of Pb2+ by bioapatite in aqueous solution.

PubMed

Shen, Zhengtao; Tian, Da; Zhang, Xinyu; Tang, Lingyi; Su, Mu; Zhang, Li; Li, Zhen; Hu, Shuijin; Hou, Deyi

2018-01-01

Bioapatite (BAp) is regarded as an effective material to immobilize lead (Pb 2+ ) via the formation of stable pyromorphite. However, when applied in contaminated soil, due to its low surface area and low adsorption capacity, BAp might not sufficiently contact and react with Pb 2+ . Biochar, a carbon storage material, typically has high surface area and high adsorption capacity. This study investigated the feasibility of using biochar as a reaction platform to enhance BAp immobilization of Pb 2+ . An alkaline biochar produced from wheat straw pellets (WSP) and a slightly acidic biochar produced from hardwood (SB) were selected. The results of aqueous adsorption showed the combination of biochar (WSP or SB) and BAp effectively removed Pb 2+ from the aqueous solution containing 1000 ppm Pb 2+ . XRD, ATR-IR, and SEM/EDX results revealed the formation of hydroxypyromorphite on both biochars' surfaces. This study demonstrates that biochars could act as an efficient reaction platform for BAp and Pb 2+ in aqueous solution due to their high surface area, porous structure, and high adsorption capacity. Therefore, it is mechanistically feasible to apply biochar to enhance BAp immobilization of Pb 2+ in contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nickel, vanadium, and lead as indicators of sediment contamination of marina, refinery, and shipyard areas.

PubMed

Pereira, Thayane Lúcia; Wallner-Kersanach, Mônica; Costa, Luiza Dy Fonseca; Costa, Daniel Pereira; Baisch, Paulo Roberto Martins

2018-01-01

Metallic elements found in the aquatic environment may originate in areas where petroleum is refined and vessels are maintained and repaired. This study aims to assess contamination caused by nickel (Ni), lead (Pb), and vanadium (V) in sediment of the Lagoa dos Patos estuary (RS, Brazil) and to evaluate them as indicators of areas under the influence of petroleum products and antifouling paints. Surface sediments were collected in summer and in winter in areas of marinas, shipyards, refinery, and a control station. High Pb and V concentrations in shipyards and at the Yacht Club showed that some organisms may be affected by toxicity. High Pb results of the index of geoaccumulation (Igeo) were found at the Yacht Club and shipyards. Al, Ni, and V had similar distribution in the sediment in both seasons. Ni and V had high relation in winter at the Yacht Club and at the Santos Shipyard, thus suggesting that these elements come mainly from petroleum products. The same happened to the relations between Pb and V, as well as Pb and Ni at the Santos Shipyard. These elements are employed as useful tools as indicators to identify places with moderate to high localized anthropogenic inputs of petroleum derivatives and antifouling paints.

Stress response of lead-exposed rainbow trout (Oncorhynchus mykiss) during swimming performance and hypoxia challenges

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

Phillips, K.A.; Caldwell, C.A.; Sandheinrich, M.B.

1995-12-31

Contaminants often invoke a stress response in aquatic organisms, and may compromise their capacity to respond to secondary stressors. This may reduce growth, reproduction and survival. The authors objectives were to assess the effects of lead and secondary stressors on hematology and blood chemistry of rainbow trout. After a 7 to 8-week aqueous exposure to Pb(100{micro}g/L), rainbow trout were challenged with forced swimming or hypoxia. Lead significantly reduced concentrations of 5-aminolevulinic acid dehydratase (ALAD), but not other constituents in the blood. Lead did not affect the swimming endurance of the fish. Hematocrit, mean cell hemoglobin content, and mean cell volumemore » were significantly lower in Pb-exposed trout following the swimming challenge. Although hypoxia resulted in increased hematocrit and plasma glucose concentrations, there were no significant differences between the Pb and control groups. Hypoxia did not affect plasma chloride concentrations, although concentrations increased in Pb-exposed trout. There was no difference in lactic acid concentrations between Pb-exposed and control fish after forced swimming or hypoxia.« less

Joint enhancement of lead accumulation in Brassica plants by EDTA and ammonium sulfate in sand culture.

PubMed

Xiong, Zhi-ting; Lu, Ping

2002-04-01

When EDTA was added alone in the Pb-contaminated sand, the plant biomass and the total Pb amount in Plant decreased in both species, Brassica pekinensis and B. juncea var. multiceps, though the shoot Pb amount increased. In contrast, when (NH4)2SO4 was added alone in the Pb-contaminated sand, little effect was observed on the shoot Pb amount, though the root Pb amount was significantly increased in B. juncea var. multiceps. When amending EDTA and (NH4)2SO4 in combination, however, the shoot Pb amount in both species substantially increased, being, on an average, 2 times and 9 times higher than that in EDTA alone or (NH4)2SO4 alone amended treatment, respectively. The two amendments showed antagonism for plant growth, but synergism for Pb bioaccumulation. B. pekinensis showed its highest level of shoot and total Pb amount in the treatment amended with EDTA and (NH4)2SO4 only a half as much as in the other treatments. It is inferred that the mechanisms responsible for the joint-enhanced Pb accumulation might be concerned with the acidification of the growth medium, cation exchange reaction and relieving EDTA induced toxicity as results by amending ammonium sulfate.

Monitoring lead in hair of children and adolescents of Alcalá de Henares, Spain. A study by gender and residential areas.

PubMed

Peña-Fernández, A; Lobo-Bedmar, M C; González-Muñoz, M J

2014-11-01

In recent years there has been an increased interest from the European Union (EU) in the development of large Human Bio-monitoring (HBM) studies across Europe, especially biomonitoring toxic metals. In Spain, most studies using hair as a biomarker have been conducted to determine occupational or industrial exposures, and have involved adult populations. Few studies have involved adolescents and children, despite these groups being sensitive to environmental contamination and pollutants. Therefore, the objective of the present study was to determine the degree of lead exposure in children and adolescents residing in Alcalá de Henares, Spain. Lead poisoning is the number one toxicological threat in the environment. So, lead (Pb) was selected as it is a persistent environmental contaminant, is measureable and is also a neurotoxin that can affect brain development. The city of Alcalá de Henares was divided into four zones to determine the influence of residence area on Pb levels. A range of other variables including age and gender were also considered within the study. The study comprised 115 children (6-9 years old) and 96 adolescents (13-16 years old). There was a significant difference between the levels of Pb in the hair of adolescents, for different gender and area of residence (p<0.001 and p<0.01 respectively). There was no significant difference in the Pb levels in hair of children, for different gender or area of the city. The levels of Pb were significantly (p<0.001) elevated in children compared to adolescents (1.48 vs. 0.70 μg/g), and there was a significant difference in Pb levels in male and female adolescent hair (0.53 vs. 0.77 μg/g) (p<0.001). The association observed between areas of residence and the Pb level in hair of the adolescent group could be mainly attributed to dietary habits and/or socioeconomic status. Copyright © 2014 Elsevier Ltd. All rights reserved.

Concentrations of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables

PubMed Central

McBride, Murray B.; Shayler, Hannah A.; Spliethoff, Henry M.; Mitchell, Rebecca G.; Marquez-Bravo, Lydia G.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Casey, Linda; Bachman, Sharon

2014-01-01

Paired vegetable/soil samples from New York City and Buffalo, NY, gardens were analyzed for lead (Pb), cadmium (Cd) and barium (Ba). Vegetable aluminum (Al) was measured to assess soil adherence. Soil and vegetable metal concentrations did not correlate; vegetable concentrations varied by crop type. Pb was below health-based guidance values (EU standards) in virtually all fruits. 47% of root crops and 9% of leafy greens exceeded guidance values; over half the vegetables exceeded the 95th percentile of market-basket concentrations for Pb. Vegetable Pb correlated with Al; soil particle adherence/incorporation was more important than Pb uptake via roots. Cd was similar to market-basket concentrations and below guidance values in nearly all samples. Vegetable Ba was much higher than Pb or Cd, although soil Ba was lower than soil Pb. The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability. PMID:25163429

Concentrations of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables.

PubMed

McBride, Murray B; Shayler, Hannah A; Spliethoff, Henry M; Mitchell, Rebecca G; Marquez-Bravo, Lydia G; Ferenz, Gretchen S; Russell-Anelli, Jonathan M; Casey, Linda; Bachman, Sharon

2014-11-01

Paired vegetable/soil samples from New York City and Buffalo, NY, gardens were analyzed for lead (Pb), cadmium (Cd) and barium (Ba). Vegetable aluminum (Al) was measured to assess soil adherence. Soil and vegetable metal concentrations did not correlate; vegetable concentrations varied by crop type. Pb was below health-based guidance values (EU standards) in virtually all fruits. 47% of root crops and 9% of leafy greens exceeded guidance values; over half the vegetables exceeded the 95th percentile of market-basket concentrations for Pb. Vegetable Pb correlated with Al; soil particle adherence/incorporation was more important than Pb uptake via roots. Cd was similar to market-basket concentrations and below guidance values in nearly all samples. Vegetable Ba was much higher than Pb or Cd, although soil Ba was lower than soil Pb. The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bioaccumulation and physiological effects of excess lead in a roadside pioneer species Sonchus oleraceus L.

PubMed

Xiong, Z T

1997-01-01

Seedlings of Sonchus oleraceus L. were transplanted to soil supplied with lead acetate at dosages of 0, 800, 1600 and 3200 mg kg(-1) DW. Measures of chlorophyll content, peroxidase (POD) activity, shoot length, biomass and Pb content in the plant tissues were obtained from the experimental plants. With increasing amounts of Pb in the soil, the chlorophyll content, shoot length and biomass decreased, while POD activity and Pb content in the plant tissues increased. At 3200 mg kg(-1) Pb treatment, Pb content in the plant leaf, stem and root were 65.67, 149.82 and 1113.24 mg kg(-1), respectively. Only at 3200 mg kg(-1) Pb treatment did chlorophyll content, shoot length and biomass significantly increase by 18, 15 and 44%, respectively, while POD decreased by 39% over the control. The potential of applying this species in phytoremediation of Pb contaminated roadside soils and thus restoration of the roadside vegetation are discussed.

Application of eggshell waste for the immobilization of cadmium and lead in a contaminated soil.

PubMed

Ok, Yong Sik; Lee, Sang Soo; Jeon, Weon-Tai; Oh, Sang-Eun; Usman, Adel R A; Moon, Deok Hyun

2011-01-01

Liming materials have been used to immobilize heavy metals in contaminated soils. However, no studies have evaluated the use of eggshell waste as a source of calcium carbonate (CaCO₃) to immobilize both cadmium (Cd) and lead (Pb) in soils. This study was conducted to evaluate the effectiveness of eggshell waste on the immobilization of Cd and Pb and to determine the metal availability following various single extraction techniques. Incubation experiments were conducted by mixing 0-5% powdered eggshell waste and curing the soil (1,246 mg Pb kg⁻¹ soil and 17 mg Cd kg⁻¹ soil) for 30 days. Five extractants, 0.01 M calcium chloride (CaCl₂), 1 M CaCl₂, 0.1 M hydrochloric acid (HCl), 0.43 M acetic acid (CH₃COOH), and 0.05 M ethylendiaminetetraacetic acid (EDTA), were used to determine the extractability of Cd and Pb following treatments with CaCO₃ and eggshell waste. Generally, the extractability of Cd and Pb in the soils decreased in response to treatments with CaCO₃ and eggshell waste, regardless of extractant. Using CaCl₂ extraction, the lowest Cd concentration was achieved upon both CaCO₃ and eggshell waste treatments, while the lowest Pb concentration was observed using HCl extraction. The highest amount of immobilized Cd and Pb was extracted by CH₃COOH or EDTA in soils treated with CaCO₃ and eggshell waste, indicating that remobilization of Cd and Pb may occur under acidic conditions. Based on the findings obtained, eggshell waste can be used as an alternative to CaCO₃ for the immobilization of heavy metals in soils.

The legacy of leaded gasoline in bottom sediment of small rural reservoirs

USGS Publications Warehouse

Juracek, K.E.; Ziegler, A.C.

2006-01-01

The historical and ongoing lead (Pb) contamination caused by the 20th-century use of leaded gasoline was investigated by an analysis of bottom sediment in eight small rural reservoirs in eastern Kansas, USA. For the reservoirs that were completed before or during the period of maximum Pb emissions from vehicles (i.e., the 1940s through the early 1980s) and that had a major highway in the basin, increased Pb concentrations reflected the pattern of historical leaded gasoline use. For at least some of these reservoirs, residual Pb is still being delivered from the basins. There was no evidence of increased Pb deposition for the reservoirs completed after the period of peak Pb emissions and (or) located in relatively remote areas with little or no highway traffic. Results indicated that several factors affected the magnitude and variability of Pb concentrations in reservoir sediment including traffic volume, reservoir age, and basin size. The increased Pb concentrations at four reservoirs exceeded the U.S. Environmental Protection Agency threshold-effects level (30.2 mg kg-1) and frequently exceeded a consensus-based threshold-effects concentration (35.8 mg kg-1) for possible adverse biological effects. For two reservoirs it was estimated that it will take at least 20 to 70 yr for Pb in the newly deposited sediment to return to baseline (pre-1920s) concentrations (30 mg kg-1) following the phase out of leaded gasoline. The buried sediment with elevated Pb concentrations may pose a future environmental concern if the reservoirs are dredged, the dams are removed, or the dams fail. ?? ASA, CSSA, SSSA.

Impact of a smelter closedown on metal contents of wheat cultivated in the neighbourhood.

PubMed

Douay, Francis; Roussel, Hélène; Pruvot, Christelle; Waterlot, Christophe

2008-03-01

The contamination of soils by heavy metals engenders important environmental and sanitary problems in Northern France where a smelter has been located for more than one hundred of years. It has been one of the most important Pb production sites in Europe until its closedown in March 2003. Ore smelting process generated considerable atmospheric emissions of dust. Despite an active environmental strategy, these emissions were still significant in 2002 with up to 17 tonnes of Pb, 32 tonnes of Zn and 1 tonne of Cd. Over the years, the generated deposits have led to an important contamination of the surrounding soils. Previous studies have shown pollutant transfers to plants, which can induce a risk for human and animal health. The objective of this study was to evaluate the consequences of the smelter closedown on the Cd and Pb contents of wheat (grain and straw) cultivated in the area. Paired topsoil and vegetable samples were taken at harvest time at various distances to the smelter. The sample sites were chosen in order to represent a large range of soil metal contamination. Sampling was realised on several wheat harvests between 1997 and 2003. 25 samples were collected before the smelter closedown and 15 after. All ears of about 1 m long of two rows were manually picked and threshed in the lab. Similarly, straw was harvested at the same time. Total metal contents in soil and wheat samples were quantified. A negative correlation between metal concentrations in soil and the distance to the smelter was shown. The wheat grain and straw showed significant Cd and Pb contents. The straw had higher metal contents than the grain. During the smelter activity, the grain contents were up to 0.8 mg kg(-1) DM of Cd and 8 mg kg(-1) DM of Pb. For the straw, maximum contents were 5 mg kg(-1) DM of Cd and 114 mg kg(-1) DM of Pb. After the smelter closedown, we observed a very large decrease of Pb in the grain (82%) and in the straw (91%). A smaller decrease was observed for Cd in grain. Despite this improvement, 80% of the studied samples remained non-acceptable for human consumption, according to the European legislation values, due to a high Cd content. Results highlighted a difference in metal accumulation in the plant organs as well as a difference in metal uptake. The approach pointed out the importance of atmospheric fallout in the wheat contamination pathways for Pb. The smelter closedown has lead to a decrease of the Pb content in wheat. It is interesting to relate this finding with the lead blood levels in children living close to the smelter. Those results have confirmed the importance of dust fallout in the plant contamination pathways. Before the closedown, Pb measured in the plant was principally originating from the smelter dust emissions. It raised the question of the sanitary risks for humans and animals living in the surrounding a of the smelter. In the literature, very few articles take the dust deposit as contamination pathways for crops into consideration. However, in highly contaminated sites, this pathway can be very important. Thus, it would be worthy studying the uptake of metal contaminants by plants through the foliar system.

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

PubMed

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

2017-05-01

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

The cadmium and lead content of the grain produced by leading Chinese rice cultivars.

PubMed

Xie, L H; Tang, S Q; Wei, X J; Shao, G N; Jiao, G A; Sheng, Z H; Luo, J; Hu, P S

2017-02-15

The cadmium (Cd) and lead (Pb) content in both white and wholemeal flour milled from 110 leading rice cultivars was assessed. The white flour Cd content ranged from <0.0025 to 0.2530mg/kg (geometric mean (GM)=0.0150mg/kg), while its Pb content ranged from <0.0250 to 0.3830mg/kg (GM=0.0210mg/kg). The indica types took up higher amounts of Cd and Pb than did the japonica types. Although the heavy metal content of wholemeal flour tended to higher than that of white flour, nevertheless 84.5% (Cd) and 95.4% (Pb) of the entries were compliant with the national maximum allowable concentration of 0.2000mg/kg of each contaminant. An analysis of the Cd content in the white flour of three indica type cultivars grown in two consecutive years at two locations indicated that Cd content may be significantly affected by the conditions prevailing in the growing season. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lead absorption mechanisms in bacteria as strategies for lead bioremediation.

PubMed

Tiquia-Arashiro, Sonia M

2018-05-08

Bacteria exhibit a number of metabolism-dependent and metabolism-independent processes for the uptake and accumulation of toxic metals. The removal of these metals from environmental sources such as soil, sludge, and wastewaters using microbe-based technologies provide an alternative for their recovery and remediation. Lead (Pb) is a pervasive metal in the environment that adversely affects all living organisms. Many aspects of metal-microbe interactions remain unexploited in biotechnology and further development and application is necessary, particularly to the problem of Pb release into the environment. Thus, this review provides a synopsis of the most important bacterial phenotypes and biochemical attributes that are instrumental in lead bioremediation, along with what is known of their genetic background that can be exploited or improved through genetic engineering. This review also highlights the potential of Pb-resistant bacteria in bringing about detoxification of Pb-contaminated terrestrial and aquatic systems in a highly sustainable and environmental friendly manner, and the existing challenges that still lie in the path to in situ and large-scale bioremediation.

BIOACCESSIBILITY TESTS ACCURATELY ESTIMATE ...

EPA Pesticide Factsheets

Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

Modified natural diatomite and its enhanced immobilization of lead, copper and cadmium in simulated contaminated soils.

PubMed

Ye, Xinxin; Kang, Shenghong; Wang, Huimin; Li, Hongying; Zhang, Yunxia; Wang, Guozhong; Zhao, Huijun

2015-05-30

Natural diatomite was modified through facile acid treatment and ultrasonication, which increased its electronegativity, and the pore volume and surface area achieved to 0.211 cm(3) g(-1) and 76.9 m(2) g(-1), respectively. Modified diatomite was investigated to immobilize the potential toxic elements (PTEs) of Pb, Cu and Cd in simulated contaminated soil comparing to natural diatomite. When incubated with contaminated soils at rates of 2.5% and 5.0% by weight for 90 days, modified diatomite was more effective in immobilizing Pb, Cu and Cd than natural diatomite. After treated with 5.0% modified diatomite for 90 days, the contaminated soils showed 69.7%, 49.7% and 23.7% reductions in Pb, Cu and Cd concentrations after 0.01 M CaCl2 extraction, respectively. The concentrations of Pb, Cu and Cd were reduced by 66.7%, 47.2% and 33.1% in the leaching procedure, respectively. The surface complexation played an important role in the immobilization of PTEs in soils. The decreased extractable metal content of soil was accompanied by improved microbial activity which significantly increased (P<0.05) in 5.0% modified diatomite-amended soils. These results suggested that modified diatomite with micro/nanostructured characteristics increased the immobilization of PTEs in contaminated soil and had great potential as green and low-cost amendments. Copyright © 2015 Elsevier B.V. All rights reserved.

Alterations of lead speciation by sulfate from addition of flue ...

EPA Pesticide Factsheets

This is the first study to evaluate the potential application of FGDG as an in situ Pb stabilizer in contaminated soils with two different compositions and to explain the underlying mechanisms. A smelter Pb contaminated soil (SM-soil), rich in ferrihydrite bound Pb (FH-Pb), cerussite and litharge with a total Pb content of 65,123 mg/kg and an organic matter rich orchard soil (BO-soil), rich in FH-Pb and humic acid bound Pb with a total Pb content of 1532 mg/kg were amended with 5% FGDG (w/w). We subjected the two soils to three leaching tests; toxicity characteristic leaching protocol (TCLP), synthetic precipitation leaching protocol (SPLP), kinetic batch leaching test (KBLT) and in-vitro bioaccessibility assay (IVBA) in order to evaluate the FGDG amendment on Pb stabilization. Solid residues of original and FGDG amended soil were analyzed using X-ray absorption spectroscopy (XAS) to identify changes in Pb speciation after each leaching test. The leachate Pb concentrations of FGDG amended soil were lowered compared to those of in non-amended soil. The linear combination fitting analysis of XAS confirmed the formation of anglesite and leadhillite in FGDG amended in soil. FGDG reduced the Pb desorption from ferrihydrite (FH), by forming FH-Pb-SO4 ternary complexes. FGDG decreased the Pb adsorption onto humic acid (HA) possibly due to the release of divalent cations such as Ca and Mg, which can compete with Pb to get adsorbed onto HA. The FGDG can successful

Accumulation and potential health risks of cadmium, lead and arsenic in vegetables grown near mining sites in Northern Vietnam.

PubMed

Bui, Anh T K; Nguyen, Ha T H; Nguyen, Minh N; Tran, Tuyet-Hanh T; Vu, Toan V; Nguyen, Chuyen H; Reynolds, Heather L

2016-09-01

The effect of environmental pollution on the safety of vegetable crops is a serious global public health issue. This study was conducted to assess heavy metal concentrations in soil, irrigation water, and 21 local vegetable species collected from four sites near mining activities and one control site in Northern Vietnam. Soils from vegetable fields in the mining areas were contaminated with cadmium (Cd), lead (Pb), and arsenic (As), while irrigation water was contaminated with Pb. Average concentrations of Pb and As in fresh vegetable samples collected at the four mining sites exceeded maximum levels (MLs) set by international food standards for Pb (70.6 % of vegetable samples) and As (44.1 % of vegetable samples), while average Cd concentrations in vegetables at all sites were below the MLs of 0.2. The average total target hazard quotient (TTHQ) across all vegetable species sampled was higher than the safety threshold of 1.0, indicating a health risk. Based on the weight of evidence, we find that cultivation of vegetables in the studied mining sites is an important risk contributor for local residents' health.

Sorghum Roots are Inefficient in Uptake of EDTA-chelated Lead

PubMed Central

Xu, Yong; Yamaji, Naoki; Shen, Renfang; Ma, Jian Feng

2007-01-01

Background and Aims Ethylene diamine tetraacetic acid (EDTA)-assisted phytoremediation has been developed to clean up lead (Pb)-contaminated soil; however, the mechanism responsible for the uptake of EDTA–Pb complex is not well understood. In this study, the accumulation process of Pb from EDTA–Pb is characterized in comparison to ionic Pb [Pb(NO3)2] in sorghum (Sorghum bicolor). Methods Sorghum seedlings were exposed to a 0·5 mm CaCl2 (pH 5·0) solution containing 0, 1 mm Pb(NO3)2 or EDTA–Pb complexes at a molar ratio of 1:0·5, 1:1, 1:2 and 1:4 (Pb:EDTA). The root elongation of sorghum at different ratios of Pb:EDTA was measured. Xylem sap was collected after the stem was severed at different times. The concentration of Pb in the shoots and roots were determined by an atomic absorption spectrometer. In addition, the roots were stained with Fluostain I for observation of the root structure. Key Results Lead accumulation in the shoots of the plants exposed to EDTA–Pb at 1:1 ratio was only one-fifth of that exposed to ionic Pb at the same concentration. Lead accumulation decreased when transpiration was suppressed. The concentration of Pb in the xylem sap from the EDTA–Pb-treated plants was about 1/25 000 of that in the external solution. Root elongation was severely inhibited by ionic Pb, but not by EDTA–Pb at a 1:1 ratio. Root staining showed that a physiological barrier was damaged in the roots exposed to ionic Pb, but not in the roots exposed to EDTA–Pb. Conclusions All these results suggest that sorghum roots are inefficient in uptake of EDTA-chelated Pb and that enhanced Pb accumulation from ionic Pb was attributed to the damaged structure of the roots. PMID:17452378

Assessment of Pb uptake, translocation and immobilization in kenaf (Hibiscus cannabinus L.) for phytoremediation of sand tailings.

PubMed

Ho, Wai Mun; Ang, Lai Hoe; Lee, Don Koo

2008-01-01

The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated. A pot experiment employing factorial design with two main effects of fertilizer and lead was conducted in a nursery using sand tailings from an ex-tin mine as the growing medium. Results showed that Pb was found in the root, stem, and seed capsule of kenaf but not in the leaf. Application of organic fertilizer promoted greater biomass yield as well as higher accumulation capacity of Pb. In Pb-spiked treatments, roots accumulated more than 85% of total plant Pb which implies that kenaf root can be an important sink for bioavailable Pb. Scanning transmission electron microscope (STEM) X-ray microanalysis confirmed that electron-dense deposits located along cell walls of kenaf roots were Pb precipitates. The ability of kenaf to tolerate Pb and avoid phytotoxicity could be attributed to the immobilization of Pb in the roots and hence the restriction of upward movement (translocation factor < 1). With the application of fertilizer, kenaf was also found to have higher biomass and subsequently higher bioaccumulation capacity, indicating its suitability for phytoremediation of Pb-contaminated site.

Protonema of the moss Funaria hygrometrica can function as a lead (Pb) adsorbent

PubMed Central

Itouga, Misao; Hayatsu, Manabu; Sato, Mayuko; Tsuboi, Yuuri; Kato, Yukari; Toyooka, Kiminori; Suzuki, Suechika; Nakatsuka, Seiji; Kawakami, Satoshi; Kikuchi, Jun

2017-01-01

Water contamination by heavy metals from industrial activities is a serious environmental concern. To mitigate heavy metal toxicity and to recover heavy metals for recycling, biomaterials used in phytoremediation and bio-sorbent filtration have recently drawn renewed attention. The filamentous protonemal cells of the moss Funaria hygrometrica can hyperaccumulate lead (Pb) up to 74% of their dry weight when exposed to solutions containing divalent Pb. Energy-dispersive X-ray spectroscopy revealed that Pb is localized to the cell walls, endoplasmic reticulum-like membrane structures, and chloroplast thylakoids, suggesting that multiple Pb retention mechanisms are operating in living F. hygrometrica. The main Pb-accumulating compartment was the cell wall, and prepared cell-wall fractions could also adsorb Pb. Nuclear magnetic resonance analysis showed that polysaccharides composed of polygalacturonic acid and cellulose probably serve as the most effective Pb-binding components. The adsorption abilities were retained throughout a wide range of pH values, and bound Pb was not desorbed under conditions of high ionic strength. In addition, the moss is highly tolerant to Pb. These results suggest that the moss F. hygrometrica could be a useful tool for the mitigation of Pb-toxicity in wastewater. PMID:29261745

High-Iron Biosolids Compost-Induced Changes in Lead and Arsenic Speciation and Bioaccessibility in Co-contaminated Soils

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

Brown, Sally L; Clausen, Ingrid; Chappell, Mark A

2012-10-23

The safety of urban farming has been questioned due to the potential for contamination in urban soils. A laboratory incubation, a field trial, and a second laboratory incubation were conducted to test the ability of high-Fe biosolids–based composts to reduce the bioaccessibility of soil Pb and As in situ. Lead and As bioaccessibility were evaluated using an in vitro assay. Changes in Pb, As, and Fe speciation were determined on select samples after the second laboratory incubation using μ–X-ray fluorescence mapping followed by μ–X-ray absorption near-edge structure (XANES). A compost with Fe added to wastewater treatment residuals (Fe WTR compost)more » added to soils at 100 g kg -1 decreased Pb bioaccessibility in both laboratory incubations. Mixed results were observed for As. Composts tested in the field trial (Fe added as Fe powder or FeCl 2) did not reduce bioaccessible Pb, and limited reductions were observed in bioaccessible As. These composts had no effect on Pb bioaccessibility during the second laboratory incubation. Bulk XANES showed association of Pb with sulfates and carbonates in the control soil. μ-XANES for three points in the Fe WTR amended soil showed Pb present as Fe-sorbed Pb (88 and 100% of two points) and pyromorphite (12 and 53% of two points). Bulk XANES of the Fe WTR compost showed 97% of total Fe present as Fe 3+. The results of this study indicate that addition of high-Fe biosolids compost is an effective means to reduce Pb accessibility only for certain types of Fe-rich materials.« less

Comparative Effects of Biochar, Slag and Ferrous-Mn Ore on Lead and Cadmium Immobilization in Soil.

PubMed

Mehmood, Sajid; Rizwan, Muhammad; Bashir, Saqib; Ditta, Allah; Aziz, Omar; Yong, Li Zhe; Dai, Zhihua; Akmal, Muhammad; Ahmed, Waqas; Adeel, Muhammad; Imtiaz, Muhammad; Tu, Shuxin

2018-02-01

A variety of remediation approaches have been applied to the heavy metals-contaminated soils, however, the immobilization of metals in co-contaminated soils still not cleared. Therefore, an incubation study was conducted to evaluate the instantaneous effects of different concentrations of biochar (BC), slag (SL) and Fe-Mn ore (FMO) on immobilization of Pb and Cd through the Toxicity Characteristic Leaching Procedure (TCLP) by following the the European Community Bureau of Reference (BCR), CaCl 2 and NH 4 NO 3 . The sequential extraction of BCR showed decrease in acid soluble fractions, while the residual proportions of Pb and Cd were enhanced with increasing concentrations of SL and BC. Addition of BC significantly lowered the extractable fractions of both metals by TCLP, NH 4 NO 3 and CaCl 2 as compared to SL and FMO. Among all amendments, BC incorporation into co-contaminated soil offered promising results for Pb and Cd immobilization. Overall, all amendments showed positive and long-term impact on the reclamation of co-contaminated soil with heavy metals and could deserve advance monitoring studies on a field scale.

NASA-DoD Lead-Free Electronics Project. DRAFT Joint Test Report

NASA Technical Reports Server (NTRS)

Kessel, Kurt

2011-01-01

The use of conventional tin-lead (SnPb) in circuit board manufacturing is under ever-increasing political scrutiny due to increasing regulations concerning lead. The "Restriction of Hazardous Substances" (RoHS) directive enacted by the European Union (EU) and a pact between the United States National Electronics Manufacturing Initiative (NEMI), Europe's Soldertec at Tin Technology Ltd. and the Japan Electronics and Information Technology Industries Association (JEITA) are just two examples where worldwide legislative actions and partnerships/agreements are affecting the electronics industry. As a result, many global commercial-grade electronic component suppliers are initiating efforts to transition to lead-free (Pb-free) in order to retain their worldwide market. Pb-free components are likely to find their way into the inventory of aerospace or military assembly processes under current government acquisition reform initiatives. Inventories "contaminated" by Pb-free will result in increased risks associated with the manufacturing, product reliability, and subsequent repair of aerospace and military electronic systems. Although electronics for military and aerospace applications are not included in the RoHS legislation, engineers are beginning to find that the commercial industry's move towards RoHS compliance has affected their supply chain and changed their parts. Most parts suppliers plan to phase out their non-compliant, leaded production and many have already done so. As a result, the ability to find leaded components is getting harder and harder. Some buyers are now attempting to acquire the remaining SnPb inventory, if it's not already obsolete. Original Equipment Manufacturers (OEMs), depots, and support contractors have to be prepared to deal with an electronics supply chain that increasingly provides more and more parts with Pb-free finishes-some labeled no differently than their Pb counterparts-while at the same time providing the traditional Pb parts. The longer the transition period, the greater the likelihood of Pb-free parts inadvertently being mixed with Pb parts and ending up on what are supposed to be Pb systems. As a result, OEMs, depots, and support contractors need to take action now to either abate the influx of Pb-free parts, or accept it and deal with the likely interim consequences of reduced reliability due to a wide variety of matters, such as Pb contamination, high temperature incompatibility, and tin whiskering. Allowance of Pb-free components produces one of the greatest risks to the reliability of a weapon system. This is due to new and poorly understood failure mechanisms, as well as unknown long-term reliability. If the decision is made to consciously allow Pb-free solder and component finishes into SnPb electronics, additional effort (and cost) will be required to make the significant number of changes to drawings and task order procedures. This project is a follow-on effort to the Joint Council on Aging Aircraft/Joint Group on Pollution Prevention (JCAA/JG-PP) Pb-free Solder Project which was the first group to test the reliability of Pb-free solder joints against the requirements of the aerospace and military community.

Phytoremediation of wastewater containing lead (Pb) in pilot reed bed using Scirpus grossus.

PubMed

Tangahu, Bieby Voijant; Abdullah, Siti Rozaimah Sheikh; Basri, Hassan; Idris, Mushrifah; Anuar, Nurina; Mukhlisin, Muhammad

2013-01-01

Phytoremediation is a technology to clean the environment from heavy metals contamination. The objectives of this study are to threat Pb contaminated wastewater by using phytoremediation technology and to determine if the plant can be mention as hyperaccumulator. Fifty plants of Scirpus grossus were grown in sand medium and 600 L spiked water in various Pb concentration (10, 30 and 50 mg/L) was exposed. The experiment was conducted with single exposure method, sampling time on day-1, day-14, day-28, day-42, day-70, and day-98. The analysis of Pb concentration in water, sand medium and inside the plant tissue was conducted by ICP-OES. Water samples were filtered and Pb concentration were directly analyzed, Pb in sand samples were extracted by EDTA method before analyzed, and Pb in plant tissues were extracted by wet digestion method and analyzed. The results showed that on day-28, Pb concentration in water decreased 100%, 99.9%, 99.7%, and the highest Pb uptake by plant were 1343, 4909, 3236 mg/kg for the treatment of 10, 30, and 50 mg/L respectively. The highest BC and TF were 485,261 on day-42 and 2.5295 on day-70 of treatment 30 mg/L, it can be mentioned that Scirpus grossus is a hyperaccumulator.

Mobility and phytoavailability of As and Pb in a contaminated soil using pine sawdust biochar under systematic change of redox conditions.

PubMed

Beiyuan, Jingzi; Awad, Yasser M; Beckers, Felix; Tsang, Daniel C W; Ok, Yong Sik; Rinklebe, Jörg

2017-07-01

Biochar has been adopted to control the mobility and phytoavailability of trace elements (TEs) in soils. To date, no attempt has been made to determine the mobility and phytoavailability of arsenic (As) and lead (Pb) in a contaminated soil with biochars as amendments under predefined redox potentials (E H ). Thus, in this study, a soil contaminated with As and Pb (2047 and 1677 mg kg -1 , respectively) was pre-incubated for 105 days with three amendments (pine sawdust biomass (BM) and two biochars produced from the same feedstock at 300 °C (BC300) and 550 °C (BC550)). The aged samples were then exposed to dynamic E H conditions to evaluate the mobility and phytoavailability of As and Pb after immobilization. The BM amendment significantly decreased and the BC300 slightly reduced the mobility and phytoavailability of As and Pb, which may be related to the oxygen-containing functional groups on the surface of BM and BC300. In contrast, BC550 increased the mobility of As at -300 to -100 mV and 100 mV, enhanced the phytoavailability of As under oxidizing condition (>100 mV), but reduced the phytoavailability of Pb, which might be caused by the properties of amendments and redox chemistry of the TEs. The effectiveness of BM and biochars for the stabilization of As and Pb varied under dynamic E H conditions, which indicates that detailed investigations should be conducted before the applications of biochar as soil amendment under variable environmental conditions, especially for contaminated paddy soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

A new insight to adsorption and accumulation of high lead concentration by exopolymer and whole cells of lead-resistant bacterium Acinetobacter junii L. Pb1 isolated from coal mine dump.

PubMed

Kushwaha, Anamika; Rani, Radha; Kumar, Sanjay; Thomas, Tarence; David, Arun Alfred; Ahmed, Meraz

2017-04-01

A lead-resistant bacterial strain was isolated from coal mine dump and identified as Acinetobacter junii Pb1 on basis of 16S rRNA (ribosomal ribonucleic acid) gene sequencing. The minimum inhibitory concentration of lead for the strain was 16,000 mg l -1 and it showed antibiotic and multi metal resistance. In aqueous culture, at an initial lead (Pb(II)) concentration of 100 and 500 mg l -1 , lead adsorption and accumulation by the isolate was 100 and 60%, at pH 7 at 30 °C after 48 and 120 h, respectively. The two fractions of exopolysaccharide (EPS), loosely associated EPS (laEPS) and bound EPS (bEPS), and whole cells (devoid of EPS) showed high binding affinity towards Pb(II). The binding affinity of laEPS towards Pb(II) (1071 mg Pb g -1 ) was three times higher than that of bEPS (321.5 mg Pb g -1 ) and 6.5 times higher than that of whole cells (165 mg Pb g -1 ). The binding affinity of EPS and whole cells with Pb(II), reported in the current study, is considerably higher as compared to that reported in the literature, till date. SEM analysis, showed an increase in thickness of cells on exposure to Pb(II) and TEM analysis, revealed its accumulation (interior of cell) and its adsorption (with the external cell surface). The isolate was also found to be positive for indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production which helps in promoting plant growth. Thus, this study provides a new understanding towards Pb(II) uptake by A. junii Pb1, highlighting its potential on the restoration of Pb(II) contaminated repositories.

Contamination by trace elements at e-waste recycling sites in Bangalore, India.

PubMed

Ha, Nguyen Ngoc; Agusa, Tetsuro; Ramu, Karri; Tu, Nguyen Phuc Cam; Murata, Satoko; Bulbule, Keshav A; Parthasaraty, Peethmbaram; Takahashi, Shin; Subramanian, Annamalai; Tanabe, Shinsuke

2009-06-01

The recycling and disposal of electronic waste (e-waste) in developing countries is causing an increasing concern due to its effects on the environment and associated human health risks. To understand the contamination status, we measured trace elements (TEs) in soil, air dust, and human hair collected from e-waste recycling sites (a recycling facility and backyard recycling units) and the reference sites in Bangalore and Chennai in India. Concentrations of Cu, Zn, Ag, Cd, In, Sn, Sb, Hg, Pb, and Bi were higher in soil from e-waste recycling sites compared to reference sites. For Cu, Sb, Hg, and Pb in some soils from e-waste sites, the levels exceeded screening values proposed by US Environmental Protection Agency (EPA). Concentrations of Cr, Mn, Co, Cu, In, Sn, Sb, Tl, Pb and Bi in air from the e-waste recycling facility were relatively higher than the levels in Chennai city. High levels of Cu, Mo, Ag, Cd, In, Sb, Tl, and Pb were observed in hair of male workers from e-waste recycling sites. Our results suggest that e-waste recycling and its disposal may lead to the environmental and human contamination by some TEs. To our knowledge, this is the first study on TE contamination at e-waste recycling sites in Bangalore, India.

EDTA ameliorates phytoextraction of lead and plant growth by reducing morphological and biochemical injuries in Brassica napus L. under lead stress.

PubMed

Kanwal, Urooj; Ali, Shafaqat; Shakoor, Muhammad Bilal; Farid, Mujahid; Hussain, Sabir; Yasmeen, Tahira; Adrees, Muhammad; Bharwana, Saima Aslam; Abbas, Farhat

2014-01-01

Brassica species are very effective in remediation of heavy metal contaminated sites. Lead (Pb) as a toxic pollutant causes number of morphological and biochemical variations in the plants. Synthetic chelator such as ethylenediaminetetraacetic acid (EDTA) improves the capability of plants to uptake heavy metals from polluted soil. In this regard, the role of EDTA in phytoextraction of lead, the seedlings of Brassica napus L. were grown hydroponically. Lead levels (50 and 100 μM) were supplied alone or together with 2.5 mM EDTA in the nutrient culture. After 7 weeks of stress, plants indicated that toxicity of Pb caused negative effects on plants and significantly reduced growth, biomass, chlorophyll content, gas exchange characteristics, and antioxidant enzymes activities such as superoxide dismutase (SOD), guaiacol peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT). Exposure to Pb induced the malondialdehyde (MDA), and hydrogen peroxide (H2O2) generation in both shoots and roots. The addition of EDTA alone or in combination with Pb significantly improved the plant growth, biomass, gas exchange characteristics, chlorophyll content, and antioxidant enzymes activities. EDTA also caused substantial improvement in Pb accumulation in Brassica plants. It can be deduced that application of EDTA significantly lessened the adverse effects of lead toxicity. Additionally, B. napus L. exhibited greater degree of tolerance against Pb toxicity and it also accumulated significant concentration of Pb from media.

In situ formation of pyromorphite is not required for the reduction of in vivo pb relative bioavailability in contaminated soils.

PubMed

Juhasz, Albert L; Gancarz, Dorota; Herde, Carina; McClure, Stuart; Scheckel, Kirk G; Smith, Euan

2014-06-17

The effect of phosphate treatment on lead relative bioavailability (Pb RBA) was assessed in three distinct Pb-contaminated soils. Phosphoric acid (PA) or rock phosphate were added to smelter (PP2), nonferrous slag (SH15), and shooting range (SR01) impacted soils at a P:Pb molar ratio of 5:1. In all of the phosphate amended soils, Pb RBA decreased compared to that in untreated soils when assessed using an in vivo mouse model. Treatment effect ratios (i.e., the ratio of Pb RBA in treated soil divided by Pb RBA in untreated soil) ranged from 0.39 to 0.67, 0.48 to 0.90, and 0.03 to 0.19 for PP2, SH15, and SR01, respectively. The decrease in Pb RBA following phosphate amendment was attributed to the formation of poorly soluble Pb phosphates (i.e., chloropyromorphite, hydroxypyromorphite, and Pb phosphate) that were identified by X-ray absorption spectroscopy (XAS). However, a similar decrease in Pb RBA was also observed in untreated soils following the sequential gavage of phosphate amendments. This suggests that in vivo processes may also facilitate the formation of poorly soluble Pb phosphates, which decreases Pb absorption. Furthermore, XAS analysis of PA-treated PP2 indicated further in vivo changes in Pb speciation as it moved through the gastrointestinal tract, which resulted in the transformation of hydroxypyromorphite to chloropyromorphite.

Physico-Chemical and Heavy Metal Profiles of Top Soils Sourced from Abandoned Lead-Zinc Mines at Enyigba, Ameri and Ameka Villages, Abakaliki District, Ebonyi State, South Eastern Nigeria

NASA Astrophysics Data System (ADS)

Osayande, D. A.; Azi, E. D.; Obayagbona, N.; Ovwasa, O. M.; Anegbe, B.

2016-12-01

Twenty (20) soil samples were collected from several abandoned old Pb - Zn mines located in Enyigba, Ameri, Ameka villages in the Abakaliki district of Ebonyi State, South-Eastern Nigeria. The soils were analyzed for Fe, Mn, Cu, Zn, Pb, Cd, Ni, Cr, V, pH, organic carbon and Electrical Conductivity using routine procedures. The physic-chemical analyses showed that pH values were generally low. The Electrical conductivity of the soils were high while organic carbon content in the soil was generally low. The heavy metal mean trend indicated that Pb (86) > Zn (64) > Cu (20) > Cd (15) > Ni (7) > Cr (6) > V (1). Fe and Mn values were also high. The variations observed for the heavy metal suggested both geogenic and anthropogenic activities were responsible for their distribution. Soil contamination was assessed on the basis of contamination factor (CF) and enrichment factor (EF). The CF values for the soil revealed moderate contamination for Ni, Cr, V, Zn and Mn, while Pb and Cd showed high contamination. The results of enrichment factor (EF) showed that using Fe concentration in the background value, Ni, Cr, V and Mn had moderate enrichment, Pb and Zn showed significant enrichment while Cd indicated high enrichment. The results of the principal component and cluster analyses showed that Zn, Cu, Cd, Pb metal originated from similar source but may have been significantly influenced by anthropogenic activities, while Ni, Cr, V were attributable to geogenic sources.

Foliar lead uptake by lettuce exposed to atmospheric fallouts.

PubMed

Uzu, Gaëlle; Sobanska, Sophie; Sarret, Géraldine; Muñoz, Manuel; Dumat, Camille

2010-02-01

Metal uptake by plants occurs by soil-root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce ( Lactuca sativa ) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 +/- 50 mg Pb kg(-1) (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination.

Spatial distribution of lead concentrations in urban surface soils of New Orleans, Louisiana USA.

PubMed

Abel, Michael T; Suedel, Burton; Presley, Steven M; Rainwater, Thomas R; Austin, Galen P; Cox, Stephen B; McDaniel, Les N; Rigdon, Richard; Goebel, Timothy; Zartman, Richard; Leftwich, Blair D; Anderson, Todd A; Kendall, Ronald J; Cobb, George P

2010-10-01

Immediately following hurricane Katrina concern was raised over the environmental impact of floodwaters on the city of New Orleans, especially in regard to human health. Several studies were conducted to determine the actual contaminant distribution throughout the city and surrounding wetlands by analyzing soil, sediment, and water for a variety of contaminants including organics, inorganics, and biologics. Preliminary investigations by The Institute of Environmental and Human Health at Texas Tech University concluded that soils and sediments contained pesticides, semi-volatiles, and metals, specifically arsenic, iron, and lead, at concentrations that could pose a significant risk to human health. Additional studies on New Orleans floodwaters revealed similar constituents as well as compounds commonly found in gasoline. More recently, it has been revealed that lead (Pb), arsenic, and vanadium are found intermittently throughout the city at concentrations greater than the human health soil screening levels (HHSSLs) of 400, 22 (non-cancer endpoint) and 390 μg/g, respectively. Of these, Pb appears to present the greatest exposure hazard to humans as a result of its extensive distribution in city soils. In this study, we spatially evaluated Pb concentrations across greater New Orleans surface soils. We established 128 sampling sites throughout New Orleans at approximately half-mile intervals. A soil sample was collected at each site and analyzed for Pb by ICP-AES. Soils from 19 (15%) of the sites had Pb concentrations exceeding the HHSSL threshold of 400 μg/g. It was determined that the highest concentrations of Pb were found in the south and west portions of the city. Pb concentrations found throughout New Orleans in this study were then incorporated into a geographic information system to create a spatial distribution model that can be further used to predict Pb exposure to humans in the city.

Toxic metal interactions affect the bioaccumulation and dietary intake of macro- and micro-nutrients.

PubMed

Khan, Anwarzeb; Khan, Sardar; Alam, Mehboob; Khan, Muhammad Amjad; Aamir, Muhammad; Qamar, Zahir; Ur Rehman, Zahir; Perveen, Sajida

2016-03-01

The present study was conducted to evaluate the effects of heavy metals (cadmium (Cd), lead (Pb) and Cd-Pb mix) on bioaccumulation of different nutrients. Three plant species including potato, tomato and lettuce were grown in pots containing soil contaminated with Cd, Pb and Cd-Pb mix at four different levels. The edible portions of each plant were analysed for Cd, Pb and different macro- and micro-nutrients including protein, vitamin C, nitrogen (N), phosphorous (P), potassium (K), iron (Fe), manganese (Mn), calcium (Ca) and magnesium (Mg). Results indicated significant variations in selected elemental concentrations in all the three plants grown in different treatments. The projected daily dietary intake values of selected metals were significant (P < 0.001) for Fe, Mn, Ca and Mg but not significant for protein, vitamin C, N and P. The elemental contribution to Recommended Dietary Allowance (RDA) was significant for Mn. Similarly, Fe and Mg also showed substantial contribution to RDA, while Ca, N, P, K, protein and vitamin C showed the minimal contribution for different age groups. This study suggests that vegetables cultivated on Cd and Pb contaminated soil may significantly affect their quality, and the consumption of such vegetables may result in substantial negative effects on nutritional composition of the consumer body. Long term and continuous use of contaminated vegetables may result in malnutrition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sediment storage and severity of contamination in a shallow reservoir affected by historical lead and zinc mining

USGS Publications Warehouse

Juracek, K.E.

2008-01-01

A combination of sediment-thickness measurement and bottom-sediment coring was used to investigate sediment storage and severity of contamination in Empire Lake (Kansas), a shallow reservoir affected by historical Pb and Zn mining. Cd, Pb, and Zn concentrations in the contaminated bottom sediment typically exceeded baseline concentrations by at least an order of magnitude. Moreover, the concentrations of Cd, Pb, and Zn typically far exceeded probable-effects guidelines, which represent the concentrations above which toxic biological effects usually or frequently occur. Despite a pre-1954 decrease in sediment concentrations likely related to the end of major mining activity upstream by about 1920, concentrations have remained relatively stable and persistently greater than the probable-effects guidelines for at least the last 50 years. Cesium-137 evidence from sediment cores indicated that most of the bottom sediment in the reservoir was deposited prior to 1954. Thus, the ability of the reservoir to store the contaminated sediment has declined over time. Because of the limited storage capacity, Empire Lake likely is a net source of contaminated sediment during high-inflow periods. The contaminated sediment that passes through, or originates from, Empire Lake will be deposited in downstream environments likely as far as Grand Lake O' the Cherokees (Oklahoma). ?? 2007 Springer-Verlag.

Zinc and lead poisoning in wild birds in the Tri-State Mining District (Oklahoma, Kansas, Missouri)

USGS Publications Warehouse

Beyer, W.N.; Dalgam, J.; Dudding, S.; French, J.B.; Mateo, R.; Miesner, J.; Sileo, L.; Spann, J.

2004-01-01

contaminated with Pb, Cd, and Zn from mining, milling and smelting. Metals have been dispersed heterogeneously throughout the District in the form of milled mine waste ('chat'), as flotation tailings and from smelters as aerial deposition or slag. This study was conducted to determine if the habitat has been contaminated to the extent that the assessment populations of wild birds are exposed to toxic concentrations of metals. American robins (Turdus migratorius), northern cardinals (Cardinalis cardinalis), and waterfowl had increased Pb tissue concentrations (p < 0.05) compared with Pb tissue concentrations from reference birds, and the exposure of songbirds to Pb was comparable with that of birds observed at other sites severely contaminated with Pb. Mean activities of the Pb-sensitive enzyme delta-aminolevulinic acid dehydratase (ALAD) were decreased by >50% in red blood cells in these birds (p < 0.05). Several birds had tissue concentrations of Pb that have been associated with impaired biological functions and external signs of poisoning. Cadmium was increased in kidneys of songbirds (p < 0.05), but no proximal tubule cell necrosis associated with Cd poisoning was observed. Zinc concentrations in liver and kidney of waterfowl were significantly higher (p < 0.05) than reference values. The increased environmental concentrations of Zn associated with mining in the District accounted for the pancreatitis previously observed in five waterfowl from the District. The District is the first site at which free-flying wild birds have been found to be suffering severe effects of Zn poisoning.

Three centuries of heavy metal pollution in Paris (France) recorded by urban speleothems.

PubMed

Pons-Branchu, Edwige; Ayrault, Sophie; Roy-Barman, Matthieu; Bordier, Louise; Borst, Wolfgang; Branchu, Philippe; Douville, Eric; Dumont, Emmanuel

2015-06-15

The first record of urban speleothems used to reconstruct the history of heavy metal pollution of shallow groundwaters is presented. Two speleothems grew during the last 300 years in an underground aqueduct in the north-eastern part of Paris. They display high Pb, Mn V, Cu, Cd and Al concentrations since 1900 due to the urbanization of the site which triggered anthropogenic contamination of the water feeding the speleothems. Surprisingly, these heavy metal concentrations are also high in the oldest part. This early pollution could come from the use of Parisian waste as fertilizers in the orchards and vineyards cultivated above the aqueduct before urbanization. Lead isotopes were measured in these carbonates as well as in lead artifacts from the 17th-18th centuries ((206)Pb/(207)Pb=1.180+/-0.003). The mean (206)Pb/(207)Pb ratio, for one of the speleothems is 1.181+/-0.003 unvarying with time. These lead signatures are close to those of coal and old lead from northern European mines, lower than the natural background signature. It confirms that the high metal concentrations found come from anthropogenic pollution. Conversely, the lead isotopic composition of the second speleothem presents two temporal trends: for the oldest levels, the mean value (1.183+/-0.003) is similar to the first speleothem. For the youngest part, a lower value (1.172+/-0.005) is recorded, evidencing the contribution of a new lead source at the beginning of the industrial revolution. Pb isotopes were also measured in recent samples from a nearby superficial site. The first sample is a recent (AD 1975+/-15 years) deposit ((206)Pb/(207)Pb=1.148+/-0.003), and the second, a thin subactual layer ((206)Pb/(207)Pb=1.181+/-0.002). These data are compatible with the adding of anthropogenic sources (leaded gasoline and industrial lead from Rio Tinto ore). Copyright © 2015 Elsevier B.V. All rights reserved.

Domain-specific effects of prenatal exposure to PCBs, mercury, and lead on infant cognition: results from the Environmental Contaminants and Child Development Study in Nunavik.

PubMed

Boucher, Olivier; Muckle, Gina; Jacobson, Joseph L; Carter, R Colin; Kaplan-Estrin, Melissa; Ayotte, Pierre; Dewailly, Éric; Jacobson, Sandra W

2014-03-01

Polychlorinated biphenyls (PCBs), methylmercury (MeHg), and lead (Pb) are environmental contaminants known for their adverse effects on cognitive development. In this study we examined the effects of prenatal exposure to PCBs, MeHg, and Pb on cognitive development in a sample of Inuit infants from Arctic Québec. Mothers were recruited at local prenatal clinics. PCBs, mercury (Hg), Pb, and two seafood nutrients-docosahexaenoic acid (DHA) and selenium (Se)-were measured in umbilical cord blood. Infants (n = 94) were assessed at 6.5 and 11 months of age on the Fagan Test of Infant Intelligence (FTII), A-not-B test, and Bayley Scales of Infant Development-2nd Edition (BSID-II). Multiple regression analyses revealed that higher prenatal PCB exposure was associated with decreased FTII novelty preference, indicating impaired visual recognition memory. Prenatal Hg was associated with poorer performance on A-not-B, which depends on working memory and is believed to be a precursor of executive function. Prenatal Pb was related to longer FTII fixation durations, indicating slower speed of information processing. PCBs, MeHg, and Pb each showed specific and distinct patterns of adverse associations with the outcomes measured during infancy. By contrast, none of these exposures was associated with performance on the BSID-II, a global developmental measure. The more focused, narrow band measures of cognitive function that appeared to be sensitive to these exposures also provide early indications of long-term impairment in specific domains that would otherwise not likely be evident until school age. Boucher O, Muckle G, Jacobson JL, Carter RC, Kaplan-Estrin M, Ayotte P, Dewailly É, Jacobson SW. 2014. Domain-specific effects of prenatal exposure to PCBs, mercury, and lead on infant cognition: results from the Environmental Contaminants and Child Development Study in Nunavik. Environ Health Perspect 122:310-316; http://dx.doi.org/10.1289/ehp.1206323.

Size-Resolved Dust and Aerosol Contaminants Associated with Copper and Lead Smelting Emissions: Implications for Emissions Management and Human Health

PubMed Central

Csavina, Janae; Taylor, Mark P.; Félix, Omar; Rine, Kyle P.; Sáez, A. Eduardo; Betterton, Eric A.

2014-01-01

Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb and other potentially toxic elements. In this work, we show that size-resolved concentrations of As and Pb generally follow a bimodal distribution with the majority of contaminants in the fine size fraction (< 1 μm) around mining activities that include smelting operations at various sites in Australia and Arizona. This evidence suggests that contaminated fine particles (< 1 μm) are the result of vapor condensation and coagulation from smelting operations while coarse particles are most likely the result of windblown dust from contaminated mine tailings and fugitive emissions from crushing and grinding activities. These results on the size distribution of contaminants around mining operations are reported to demonstrate the ubiquitous nature of this phenomenon so that more effective emissions management and practices that minimize health risks associated with metal extraction and processing can be developed. PMID:24995641

Design and development of amperometric biosensor for the detection of lead and mercury ions in water matrix-a permeability approach.

PubMed

Gumpu, Manju Bhargavi; Krishnan, Uma Maheswari; Rayappan, John Bosco Balaguru

2017-07-01

Intake of water contaminated with lead (Pb 2+ ) and mercury (Hg 2+ ) ions leads to various toxic effects and health issues. In this context, an amperometric urease inhibition-based biosensor was developed to detect Pb 2+ and Hg 2+ ions in water matrix. The modified Pt/CeO 2 /urease electrode was fabricated by immobilizing CeO 2 nanoparticles and urease using a semi-permeable adsorption layer of nafion. With urea as a substrate, urease catalytic activity was examined through cyclic voltammetry. Further, maximum amperometric inhibitive response of the modified Pt/CeO 2 /urease electrode was observed in the presence of Pb 2+ and Hg 2+ ions due to the urease inhibition at specific potentials of -0.03 and 0 V, respectively. The developed sensor exhibited a detection limit of 0.019 ± 0.001 μM with a sensitivity of 89.2 × 10 -3  μA μM -1 for Pb 2+ ions. A detection limit of 0.018 ± 0.003 with a sensitivity of 94.1 × 10 -3  μA μM -1 was achieved in detecting Hg 2+ ions. The developed biosensor showed a fast response time (<1 s) with a linear range of 0.5-2.2 and 0.02-0.8 μM for Pb 2+ and Hg 2+ ions, respectively. The modified electrode offered a good stability for 20 days with a good repeatability and reproducibility. The developed sensor was used to detect Pb 2+ and Hg 2+ ions contaminating Cauvery river water and the observed results were in good co-ordination with atomic absorption spectroscopic data.

Geochemical and Pb isotopic characterization of soil, groundwater, human hair, and corn samples from the Domizio Flegreo and Agro Aversano area (Campania region, Italy)

USGS Publications Warehouse

Rezza, Carmela; Albanese, Stefano; Ayuso, Robert A.; Lima, Annamaria; Sorvari, Jaana; De Vivo, Benedetto

2018-01-01

A geochemical survey was carried out to investigate metal contamination in the Domizio Littoral and Agro Aversano area (Southern Italy) by means of soil, groundwater, human hair and corn samples. Pb isotope ratios were also determined to identify the sources of metals. Specifically, the investigation focused on topsoils (n = 1064), groundwater (n = 26), 25 human hair (n = 24) and corn samples (n = 13). Topsoils have been sampled and analysed in a previous study for 53 elements (including potentially harmful ones), and determined by ICP-MS after dissolving with aqua regia. Groundwater was analysed for 72 elements by ICP-MS and by ICP-ES. Samples of human hair were prepared and analysed for 16 elements by ICP-MS. Dried corn collected at several farms were also analysed for 53 elements by ICP-MS. The isotopic ratios of 206Pb/207Pb and 208Pb/207Pb in selected topsoil (n = 24), groundwater (n = 9), human hair (n = 9) and corn (n = 4) samples were analysed from both eluates and residues to investigate possible anthropogenic contamination and geogenic contributions. All data were processed and mapped by ArcGis software to produce interpolated maps and contamination factor maps of potentially harmful elements, in accordance with Italian Environmental Law (Legislative Decree 152/06). Results show that soil sampling sites are characterized by As, Cd, Co, Cr, Cu, Hg, Pb, Se, and Zn contents exceeding the action limits established for residential land use (RAL) and, in some cases, also the action limits for industrial land use (IAL) as established by Legislative Decree 152/06. A map of contamination factors and a map showing the degrees of contamination indicate that the areas in the municipalities of Acerra, Casoria and Giugliano have been affected by considerable anthropogenic-related pollution. To interpret the isotopic data and roughly estimate proportion of Pb from an anthropogenic source we broadly defined possible natural and anthropogenic Pb end-member fields based on literature data. For example, we summarized data for Vesuvius and Campi Flegrei volcanic rocks, gasoline, and aerosol deposits.Lead isotope data show mixing between geogenic and anthropogenic sources. Topsoil, groundwater, human hair and corn samples show a greater contribution from geogenic sources like the Yellow Tuff (from Campi Flegrei) and volcanic rocks from Mt. Vesuvius. Aerosols, fly ash and gasoline (anthropogenic sources) have also been contributors. In detail, 46% of the topsoil residues, 96% of topsoil leachates, 88% of groundwater, 90% of human hair, and 25% of corn samples indicate that > 50% percent of the lead in this area can be ascribed to anthropogenic activity.

Lead-resistant strain KQBT-3 inoculants of Tricholoma lobayensis Heim that enhance remediation of lead-contaminated soil.

PubMed

Li, Ying; Qin, Chui-Xin; Gao, Biyu; Hu, Yuanjia; Xu, Heng

2015-01-01

To enhance lead-detoxifying efficiency of Tricholoma lobayensis Heim, one lead-resistant strain KQBT-3 (Bacillus thuringiensis) was applied owing to its excellent ability to tolerate Pb. KQBT-3 domesticated in liquid medium with increasing lead concentrations could tolerate Pb(NO3)2 up to a concentration of 800 mg L(-1). Pot experiments showed that the KQBT-3 not only could promote the growth of T. lobayensis, but also could enhance its Pb accumulation ability under heavy metal stress. Biomass and accumulation of Pb increased 47.3% and 33.2%, respectively. In addition, after inoculation of KQBT-3, the significant decrease of malondialdehyde indicated KQBT-3 could alleviate lipid peroxidation in T. lobayensis. What is interesting is that superoxide dismutase and peroxidase activities in T. lobayensis inoculated with KQBT-3 were increased, and the maximum increasing rate was 121.71% and 117.29%, respectively. However, the catalase activity increased slightly. This revealed that inoculating KQBT-3 further induced oxidative response in T. lobayensis due to Pb accumulation. Therefore, the present work showed that KQBT-3 made a major contribution to promote growth and lead uptake of T. lobayensis and alleviate the oxidative stress. This kind of auxiliary effect on macrofungi can be developed into a novel bioremediation strategy.

Spatial distribution, health risk assessment, and isotopic composition of lead contamination of street dusts in different functional areas of Beijing, China.

PubMed

Han, Lanfang; Gao, Bo; Wei, Xin; Xu, Dongyu; Gao, Li

2016-02-01

Street dusts from heavy density traffic area (HDTA), tourism area (TA), residential area (RA), and educational area (EA) in Beijing were collected to explore the distribution, health risk assessment, and source of lead (Pb). The average concentration of Pb in TA was the highest among the four areas. Compared with other cities, Pb concentrations in Beijing were generally at moderate or low levels. The average value (14.05) of ecological risk index (RI) indicated that Pb was at "low pollution risk" status. According to the calculation on hazard index (HI), the ingestion of dust particles of children and adults was the major route of exposure to street dusts in four studied areas, followed by dermal contact. The lower values of HI than 1 further suggested that non-carcinogenic risks of Pb in the street dusts were in the low range. Comparing (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of street dusts with other environmental samples, it was found that atmospheric deposition of coal combustion dust might be the main pathway for anthropogenic Pb input to the street dusts in four functional areas.

Holistic risk assessment of surface water contamination due to Pb-210 in oil produced water from the Bakken Shale.

PubMed

Torres, Luisa; Yadav, Om Prakash; Khan, Eakalak

2017-02-01

A holistic risk assessment of surface water (SW) contamination due to lead-210 (Pb-210) in oil produced water (PW) from the Bakken Shale in North Dakota (ND) was conducted. Pb-210 is a relatively long-lived radionuclide and very mobile in water. Because of limited data on Pb-210, a simulation model was developed to determine its concentration based on its parent radium-226 and historical total dissolved solids levels in PW. Scenarios where PW spills could reach SW were analyzed by applying the four steps of the risk assessment process. These scenarios are: (1) storage tank overflow, (2) leakage in equipment, and (3) spills related to trucks used to transport PW. Furthermore, a survey was conducted in ND to quantify the risk perception of PW from different stakeholders. Findings from the study include a low probability of a PW spill reaching SW and simulated concentration of Pb-210 in drinking water higher than the recommended value established by the World Health Organization. Also, after including the results from the risk perception survey, the assessment indicates that the risk of contamination of the three scenarios evaluated is between medium-high to high. Copyright © 2016 Elsevier Ltd. All rights reserved.

Concentrations of arsenic, cadmium and lead in human hair and typical foods in eleven Chinese cities.

PubMed

Zhou, Tong; Li, Zhu; Zhang, Fan; Jiang, Xiaosan; Shi, Weiming; Wu, Longhua; Christie, Peter

2016-12-01

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) were determined in 384 human hair samples and 445 purchased food samples from 11 cities in China. The mean concentrations of hair As, Cd and Pb were 0.23, 0.062 and 2.45mgkg -1 , respectively. The As, Cd and Pb concentrations in different foods were lower than the national maximum allowable contaminant levels. By comparison, males had higher hair As concentrations but lower Cd concentrations than females. When the interaction effects of gender and age were considered, males had the higher hair As, Cd and Pb concentrations in the 51-65 year-old age group. Residents of rural areas had higher hair As, Cd and Pb concentrations than people living in urban areas. Further analysis indicates that hair As, Cd and Pb concentrations and their changes with biological and environmental factors cannot be satisfactorily explained by the estimated intakes from purchased food. Copyright © 2016 Elsevier B.V. All rights reserved.

Field experiment for determining lead accumulation in rice grains of different genotypes and correlation with iron oxides deposited on rhizosphere soil.

PubMed

Lai, Yu-Cheng; Syu, Chien-Hui; Wang, Pin-Jie; Lee, Dar-Yuan; Fan, Chihhao; Juang, Kai-Wei

2018-01-01

Paddy rice (Oryza sativa L.) is a major staple crop in Asia. However, heavy metal accumulation in paddy soil poses a health risk for rice consumption. Although plant uptake of Pb is usually low, Pb concentrations in rice plants have been increasing with Pb contamination in paddy fields. It is known that iron oxide deposits in the rhizosphere influence the absorption of soil Pb by rice plants. In this study, 14 rice cultivars bred in Taiwan, including ten japonica cultivars (HL21, KH145, TC192, TK9, TK14, TK16, TN11, TNG71, TNG84, and TY3) and four indica cultivars (TCS10, TCS17, TCSW2, and TNGS22), were used in a field experiment. We investigated the genotypic variation in rice plant Pb in relation to iron oxides deposited in the rhizosphere, as seen in a suspiciously contaminated site in central Taiwan. The results showed that the cultivars TCSW2, TN11, TNG71, and TNG84 accumulated brown rice Pb exceeding the tolerable level of 0.2mgkg -1 . In contrast, the cultivars TNGS22, TK9, TK14, and TY3 accumulated much lower brown rice Pb (<0.1mgkg -1 ); therefore, they should be prioritized as safe cultivars for sites with potential contamination. Moreover, the iron oxides deposited on the rhizosphere soil show stronger affinity to soil-available Pb than those on the root surface to form iron plaque. The relative tendency of Pb sequestration toward rhizosphere soil was negatively correlated with the Pb concentrations in brown rice. The iron oxides deposited on the rhizosphere soil but not on the root surface to form iron plaque dominate Pb sequestration in the rhizosphere. Therefore, the enhancement of iron oxide deposits on the rhizosphere soil could serve as a barrier preventing soil Pb on the root surface and result in reduced Pb accumulation in brown rice. Copyright © 2017 Elsevier B.V. All rights reserved.

Human health risk from heavy metal via food crops consumption with wastewater irrigation practices in Pakistan.

PubMed

Khan, Muhammad Usman; Malik, Riffat Naseem; Muhammad, Said

2013-11-01

The current study was designed to investigate the potential human health risks associated with consumption of food crops contaminated with toxic heavy metals. Cadmium (Cd) concentration in surface soils; Cd, lead (Pb) and chromium (Cr) in the irrigation water and food crops were above permissible limits. The accumulation factor (AF) was >1 for manganese (Mn) and Pb in different food crops. The Health Risk Index (HRI) was >1 for Pb in all food crops irrigated with wastewater and tube well water. HRI >1 was also recorded for Cd in all selected vegetables; and for Mn in Spinacia oleracea irrigated with wastewater. All wastewater irrigated samples (soil and food crops) exhibited high relative contamination level as compared to samples irrigated with tube well water. Our results emphasized the need for pretreatment of wastewater and routine monitoring in order to avoid contamination of food crops from the wastewater irrigation system. Copyright © 2013 Elsevier Ltd. All rights reserved.

Screening hydroxyapatite for cadmium and lead immobilization in aqueous solution and contaminated soil: The role of surface area.

PubMed

Li, Hongying; Guo, Xisheng; Ye, Xinxin

2017-02-01

Hydroxyapatite (HAP) has been widely used to immobilize many cationic metals in water and soils. The specific reason why an increase in the surface area of HAP enhances cadmium (Cd) uptake, but has no effect on lead (Pb) uptake, is not clear. The aim of this study was to determine the factors causing the differences in sorption behavior between Cd and Pb by evaluating HAPs with different surface areas. We synthesized HAPs with two different surface areas, which were characterized by X-ray diffraction, N 2 adsorption, and scanning electron microscopy, and then evaluated them as sorbents for Cd and Pb removal by testing in single and binary systems. The sorption capacity of large surface area HAP (1.85mmol/g) for Cd in the single-metal system was higher than that of small surface area HAP (0.64mmol/g), but there were no differences between single- and binary-metal solutions containing Pb. After the Cd experiments, the HAP retained a stable structure and intact morphology, which promotes the accessibility of reactive sites for Cd. However, a newly formed precipitate covered the surface and blocked the channels in the presence of Pb, which reduced the number of potential adsorption sites on HAP for Cd and Pb. Remediation experiments using Cd- and Pb-contaminated soil produced similar results to the solution tests. These results indicate that alterations of the structure and morphology during the reaction is an important factor influencing metal sorption to HAP. Copyright © 2016. Published by Elsevier B.V.

Sorbent-embedded sheets for safe drinking water in developing countries: a case study of lead(II) removal by a zeolite-embedded sheet.

PubMed

Botoman, Lester; Shukla, Elvis; Johan, Erni; Mitsunobu, Satoshi; Matsue, Naoto

2018-02-01

Although many kinds of materials for water purification are known, easy-to-use methods that ensure the safety of drinking water for rural populations are not sufficiently available. Sorbent-embedded sheets provide methods for the easy removal of contaminants from drinking water in the home. As an example of such a sorbent-embedded sheet, we prepared a Linde type A (LTA) zeolite-embedded sheet (ZES) and examined its Pb(II) removal behaviour. Different amounts of LTA were added either as powder or as ZES to 0.3 mM Pb(NO 3 ) 2 solutions containing 2.5 mM Ca(NO 3 ) 2 , in which the ratio of the negative charges in LTA to the positive charges in Pb(II) (LTA/Pb ratio) ranged from 1 to 20. After shaking, the mixtures were centrifuged to remove the powder, while the ZES was simply removed from the mixture by hand. The LTA powder removed more than 99% of the Pb(II) from the solution at all LTA/Pb ratios within 1 h, while the ZES removed >99% of the Pb(II) at LTA/Pb ratios of 2 and higher; at the highest LTA/Pb ratio of 20, the ZES removed >99% of the Pb(II) in 30 s. Therefore, the use of appropriate sorbent-embedded sheets enable the facile removal of contaminants from water.

Concentrations of cadmium, lead, and zinc in fish from mining-influenced waters of northeastern Oklahoma: Sampling of blood, carcass, and liver for aquatic biomonitoring

USGS Publications Warehouse

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

2005-01-01

The Tri-States Mining District (TSMD) of Missouri (MO), Kansas (KS), and Oklahoma (OK), USA, was mined for lead (Pb) and zinc (Zn) for more than a century. Mining ceased more than 30 years ago, but wastes remain widely distributed in the region, and there is evidence of surface- and groundwater contamination in the Spring River-Neosho River (SR-NR) system of northeastern OK. In October 2001, we collected a total of 74 fish from six locations in the SR-NR system that included common carp (Cyprinus carpio), channel- and flathead catfish (Ictalurus punctatus and Pylodictis olivaris), largemouth- and spotted bass (Micropterus salmoides and Micropterus punctulatus), and white crappie (Pomoxis annularis). We obtained additional fish from locations in MO that included three reference sites and one site that served as a "positive control" (heavily contaminated by Pb). Blood, carcass (headed, eviscerated, and scaled) and liver (carp only) samples were analyzed for cadmium (Cd), Pb, and Zn. Our objectives were to assess the degree to which fish from the OK portion of the SR-NR system are contaminated by these elements and to evaluate fish blood sampling for biomonitoring. Concentrations of Cd and Pb in carp and catfish from OK sites were elevated and Pb concentrations of some approached those of the highly contaminated site in MO, but concentrations in bass and crappie were relatively low. For Zn, correlations were weak among concentrations in the three tissues and none of the samples appeared to reflect site contamination. Variability was high for Cd in all three tissues of carp; differences between sites were statistically significant (p < 0.05) only for blood even though mean liver concentrations were at least 100-fold greater than those in blood. Blood concentrations of Cd and Pb were positively correlated (r 2 = 0.49 to 0.84) with the concentration of the same element in carp and catfish carcasses or in carp livers, and the corresponding multiple regression models were highly significant (p < 0.001). Our data indicate that potentially nonlethal blood sampling can be useful for monitoring of selected metals in carp, catfish, and perhaps other fishes. ?? 2005 Springer Science+Business Media, Inc.

Variations in metal tolerance and accumulation in three hydroponically cultivated varieties of Salix integra treated with lead.

PubMed

Wang, Shufeng; Shi, Xiang; Sun, Haijing; Chen, Yitai; Pan, Hongwei; Yang, Xiaoe; Rafiq, Tariq

2014-01-01

Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb) tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou), a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI) and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production), but a low translocation factor (TF), indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests.

Variations in Metal Tolerance and Accumulation in Three Hydroponically Cultivated Varieties of Salix integra Treated with Lead

PubMed Central

Sun, Haijing; Chen, Yitai; Pan, Hongwei; Yang, Xiaoe; Rafiq, Tariq

2014-01-01

Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb) tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou), a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI) and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production), but a low translocation factor (TF), indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests. PMID:25268840

Experimental determination of lead carbonate solubility at high ionic strengths: A Pitzer model description

DOE PAGES

Xiong, Yongliang

2015-05-06

In this article, solubility measurements of lead carbonate, PbCO 3(cr), cerussite, as a function of total ionic strengths are conducted in the mixtures of NaCl and NaHCO 3 up to I = 1.2 mol•kg –1 and in the mixtures of NaHCO 3 and Na 2CO 3 up to I = 5.2 mol•kg –1, at room temperature (22.5 ± 0.5 °C). The solubility constant (log K sp) for cerussite, PbCO 3(cr) = Pb 2+ + CO 3 2- was determined as –13.76 ± 0.15 (2σ) with a set of Pitzer parameters describing the specific interactions of PbCO 3(aq), Pb(CO 3) 2more » 2-, and Pb(CO 3)Cl – with the bulk-supporting electrolytes, based on the Pitzer model. The model developed in this work can reproduce the experimental results including model-independent solubility values from the literature over a wide range of ionic strengths with satisfactory accuracy. The model is expected to find applications in numerous fields, including the accurate description of chemical behavior of lead in geological repositories, the modeling of formation of oxidized Pb–Zn ore deposits, and the environmental remediation of lead contamination.« less

Contamination of food crops grown on soils with elevated heavy metals content.

PubMed

Dziubanek, Grzegorz; Piekut, Agata; Rusin, Monika; Baranowska, Renata; Hajok, Ilona

2015-08-01

The exposure of inhabitants from 13 cities of The Upper Silesia Industrial Region to cadmium and lead has been estimated on the basis of heavy metals content in commonly consumed vegetables. The samples were collected from agricultural fields, allotments and home gardens in these cities. Cadmium and lead concentrations in samples of soil and vegetables - cabbage, carrots and potatoes were determined. High content of heavy metals in the arable layer of soil in Upper Silesia (max. 48.8 and 2470mgkg(-1) d.w. for Cd and Pb, respectively) explained high Cd and Pb concentrations in locally cultivated vegetables which are well above the permissible level. Three exposure scenarios with different concentrations of Pb and Cd in vegetables were taken into consideration. In the Scenario I where the content of heavy metals was equal to maximum permissible level, the value of hazard quotient (HQ) for Pb and Cd was 0.530 and 0.704, respectively. In the scenarios where were assumed consumption of contaminated vegetables from Upper Silesia the value of hazard quotient (HQ) for Pb and Cd was 0.755 and 1.337 for Scenario II and 1.806 and 4.542 for Scenario III. The study showed that consumption of vegetables cultivated in Upper Silesia Region on the agricultural fields, allotments and in home gardens may pose a significant health risk. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Contaminants in surface water and sediments near the Tynagh silver mine site, County Galway, Ireland.

PubMed

O'Neill, A; Phillips, D H; Bowen, J; Sen Gupta, B

2015-04-15

A former silver mine in Tynagh, Co. Galway, Ireland is one of the most contaminated mine sites in Europe with maximum concentrations of Zn, As, Pb, Mn, Ni, Cu, and Cd far exceeding guideline values for water and sediment. The aims of this research were to 1) further assess the contamination, particularly metals, in surface water and sediment around the site, and 2) determine if the contamination has increased 10 years after the Environmental Protection Agency Ireland (EPAI) identified off-site contamination. Site pH is alkaline to neutral because CaCO3-rich sediment and rock material buffer the exposed acid generating sulphide-rich ore. When this study was compared to the previous EPAI study conducted 10 years earlier, it appeared that further weathering of exposed surface sediment had increased concentrations of As and other potentially toxic elements. Water samples from the tailings ponds and adjacent Barnacullia Stream had concentrations of Al, Cd, Mn, Zn and Pb above guideline values. Lead and Zn concentrations from the tailings pond sediment were 16 and 5 times higher, respectively, than concentrations reported 10 years earlier. Pb and Zn levels in most sediment samples exceeded the Expert Group (EGS) guidelines of 1000 and 5000 mg/kg, respectively. Arsenic concentrations were as high as 6238 mg/kg in the tailings ponds sediment, which is 62 and 862 times greater than the EGS and Canadian Soil Quality Guidelines (CSQG), respectively. Cadmium, Cu, Fe, Mn, Pb and Zn concentrations in water and sediment were above guideline values downstream of the site. Additionally, Fe, Mn and organic matter (OM) were strongly correlated and correlated to Zn, Pb, As, Cd, Cu and Ni in stream sediment. Therefore, the nearby Barnacullia Stream is also a significant pathway for contaminant transport to downstream areas. Further rehabilitation of the site may decrease the contamination around the area. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution and assessment of Pb in the supergene environment of the Huainan Coal Mining Area, Anhui, China.

PubMed

Fang, Ting; Liu, Guijian; Zhou, Chuncai; Yuan, Zijiao; Lam, Paul Kwan Sing

2014-08-01

Coal mining area is highly subject to lead (Pb) pollution from coal mining activities. Several decades of coal mining and processing practices in dozens of coal mines in the Huainan Coal Mining Area (HCMA) have led to the accumulation of massive amounts of coal gangue, which piled in dumps. In order to investigate the impacts of coal gangue dumps on Pb level in the supergene media of the HCMA, a systematic sampling campaign comprising coal gangue, soil, wheat, and earthworm samples was conducted. The average Pb content in the coal mining area soil is 24 mg/kg, which is slightly higher than the associated coal gangues (23 mg/kg) and markedly higher than reference region soil (12.6 mg/kg). Soil in the HCMA present a slight to moderate Pb contamination, which might be related to the weathering and leaching of coal gangue dumps. Lateral distribution of Pb in HCMA soil differed among individual coal mines. The soil profile distribution of Pb depends on both natural and anthropogenic contributions. Average Pb content is higher in roots than in stems, leaves, and wheat husks, while the Pb level in seeds exceeded the maximum Pb allowance for foods (Maximum Levels of Contaminants in Foods of China, GB 2762-2012). Earthworms in the selected area are significantly enriched in Pb, suggesting higher bio-available Pb level in soil in the HCMA.

Contaminant Removal From Natural Resources

NASA Technical Reports Server (NTRS)

Clausen, Christian A. (Inventor); Quinn, Jacqueline W. (Inventor); Geiger, Cheri L. (Inventor); Reinhart, Debra (Inventor); Fillpek, Laura B. (Inventor); Coon, Christina (Inventor); Devor, Robert (Inventor)

2006-01-01

A zero-valent metal emulsion containing zero-valent metal particles is used to remediate contaminated natural resources, such as groundwater and soil. In a preferred embodiment, the zero-valent metal emulsion removes heavy metals, such as lead (pb), from contaminated natural resources. In another preferred embodiment, the zero-valent metal emulsion is a bimetallic emulsion containing zero-valent metal particles doped with a catalytic metal to remediate halogenated aromatic compounds, such as polychlorinated biphenyls (PCBs), from natural resources.

Citric acid improves lead (pb) phytoextraction in brassica napus L. by mitigating pb-induced morphological and biochemical damages.

PubMed

Shakoor, Muhammad Bilal; Ali, Shafaqat; Hameed, Amjad; Farid, Mujahid; Hussain, Sabir; Yasmeen, Tahira; Najeeb, Ullah; Bharwana, Saima Aslam; Abbasi, Ghulam Hasan

2014-11-01

Phytoextraction is an environmentally friendly and a cost-effective strategy for remediation of heavy metal contaminated soils. However, lower bioavailability of some of the metals in polluted environments e.g. lead (Pb) is a major constraint of phytoextraction process that could be overcome by applying organic chelators. We conducted a glasshouse experiment to evaluate the role of citric acid (CA) in enhancing Pb phytoextraction. Brassica napus L. seedlings were grown in hydroponic media and exposed to various treatments of Pb (50 and 100 μM) as alone or in combination with CA (2.5mM) for six weeks. Pb-induced damage in B. napus toxicity was evident from elevated levels of malondialdehyde (MDA) and H2O2 that significantly inhibited plant growth, biomass accumulation, leaf chlorophyll contents and gas exchange parameters. Alternatively, CA application to Pb-stressed B. napus plants arrested lipid membrane damage by limiting MDA and H2O2 production and by improving antioxidant enzyme activities. In addition, CA significantly increased the Pb accumulation in B. napus plants. The study concludes that CA has a potential to improve Pb phytoextraction without damaging plant growth. Copyright © 2014 Elsevier Inc. All rights reserved.

The Combined Effects of Arbuscular Mycorrhizal Fungi (AMF) and Lead (Pb) Stress on Pb Accumulation, Plant Growth Parameters, Photosynthesis, and Antioxidant Enzymes in Robinia pseudoacacia L.

DOE PAGES

Yang, Yurong; Han, Xiaozhen; Liang, Yan; ...

2015-12-23

Arbuscular mycorrhizal fungi (AMF) are considered as a potential biotechnological tool for improving phytostabilization efficiency and plant tolerance to heavy metal-contaminated soils. However, the mechanisms through which AMF help to alleviate metal toxicity in plants are still poorly understood. A greenhouse experiment was conducted to evaluate the effects of two AMF species (Funneliformis mosseae and Rhizophagus intraradices) on the growth, Pb accumulation, photosynthesis and antioxidant enzyme activities of a leguminous tree (Robinia pseudoacacia L.) at Pb addition levels of 0, 500, 1000 and 2000 mg kg -1 soil. AMF symbiosis decreased Pb concentrations in the leaves and promoted the accumulationmore » of biomass as well as photosynthetic pigment contents. Mycorrhizal plants had higher gas exchange capacity, non-photochemistry efficiency, and photochemistry efficiency compared with non-mycorrhizal plants. The enzymatic activities of superoxide dismutase (SOD), ascorbate peroxidases (APX) and glutathione peroxidase (GPX) were enhanced, and hydrogen peroxide (H 2O 2) and malondialdehyde (MDA) contents were reduced in mycorrhizal plants. These findings suggested that AMF symbiosis could protect plants by alleviating cellular oxidative damage in response to Pb stress. Furthermore, mycorrhizal dependency on plants increased with increasing Pb stress levels, indicating that AMF inoculation likely played a more important role in plant Pb tolerance in heavily contaminated soils. Overall, both F. mosseae and R. intraradices were able to maintain efficient symbiosis with R. pseudoacacia in Pb polluted soils. AMF symbiosis can improve photosynthesis and reactive oxygen species (ROS) scavenging capabilities and decrease Pb concentrations in leaves to alleviate Pb toxicity in R. pseudoacacia. In conclusion, our results suggest that the application of the two AMF species associated with R. pseudoacacia could be a promising strategy for enhancing the phytostabilization efficiency of Pb contaminated soils.« less

The Combined Effects of Arbuscular Mycorrhizal Fungi (AMF) and Lead (Pb) Stress on Pb Accumulation, Plant Growth Parameters, Photosynthesis, and Antioxidant Enzymes in Robinia pseudoacacia L.

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

Yang, Yurong; Han, Xiaozhen; Liang, Yan

Arbuscular mycorrhizal fungi (AMF) are considered as a potential biotechnological tool for improving phytostabilization efficiency and plant tolerance to heavy metal-contaminated soils. However, the mechanisms through which AMF help to alleviate metal toxicity in plants are still poorly understood. A greenhouse experiment was conducted to evaluate the effects of two AMF species (Funneliformis mosseae and Rhizophagus intraradices) on the growth, Pb accumulation, photosynthesis and antioxidant enzyme activities of a leguminous tree (Robinia pseudoacacia L.) at Pb addition levels of 0, 500, 1000 and 2000 mg kg -1 soil. AMF symbiosis decreased Pb concentrations in the leaves and promoted the accumulationmore » of biomass as well as photosynthetic pigment contents. Mycorrhizal plants had higher gas exchange capacity, non-photochemistry efficiency, and photochemistry efficiency compared with non-mycorrhizal plants. The enzymatic activities of superoxide dismutase (SOD), ascorbate peroxidases (APX) and glutathione peroxidase (GPX) were enhanced, and hydrogen peroxide (H 2O 2) and malondialdehyde (MDA) contents were reduced in mycorrhizal plants. These findings suggested that AMF symbiosis could protect plants by alleviating cellular oxidative damage in response to Pb stress. Furthermore, mycorrhizal dependency on plants increased with increasing Pb stress levels, indicating that AMF inoculation likely played a more important role in plant Pb tolerance in heavily contaminated soils. Overall, both F. mosseae and R. intraradices were able to maintain efficient symbiosis with R. pseudoacacia in Pb polluted soils. AMF symbiosis can improve photosynthesis and reactive oxygen species (ROS) scavenging capabilities and decrease Pb concentrations in leaves to alleviate Pb toxicity in R. pseudoacacia. In conclusion, our results suggest that the application of the two AMF species associated with R. pseudoacacia could be a promising strategy for enhancing the phytostabilization efficiency of Pb contaminated soils.« less

Pb-Sr isotopic and geochemical constraints on sources and processes of lead contamination in well waters and soil from former fruit orchards, Pennsylvania, USA: A legacy of anthropogenic activities

USGS Publications Warehouse

Ayuso, Robert A.; Foley, Nora K.

2016-01-01

Isotopic discrimination can be an effective tool in establishing a direct link between sources of Pb contamination and the presence of anomalously high concentrations of Pb in waters, soils, and organisms. Residential wells supplying water containing up to 1600 ppb Pb to houses built on the former Mohr orchards commercial site, near Allentown, PA, were evaluated to discern anthropogenic from geogenic sources. Pb (n = 144) and Sr (n = 40) isotopic data and REE (n = 29) data were determined for waters from residential wells, test wells (drilled for this study), and surface waters from pond and creeks. Local soils, sediments, bedrock, Zn-Pb mineralization and coal were also analyzed (n = 94), together with locally used Pb-As pesticide (n = 5). Waters from residential and test wells show overlapping values of 206Pb/207Pb, 208Pb/207Pb and 87Sr/86Sr. Larger negative Ce anomalies (Ce/Ce*) distinguish residential wells from test wells. Results show that residential and test well waters, sediments from residential water filters in water tanks, and surface waters display broad linear trends in Pb isotope plots. Pb isotope data for soils, bedrock, and pesticides have contrasting ranges and overlapping trends. Contributions of Pb from soils to residential well waters are limited and implicated primarily in wells having shallow water-bearing zones and carrying high sediment contents. Pb isotope data for residential wells, test wells, and surface waters show substantial overlap with Pb data reflecting anthropogenic actions (e.g., burning fossil fuels, industrial and urban processing activities). Limited contributions of Pb from bedrock, soils, and pesticides are evident. High Pb concentrations in the residential waters are likely related to sediment build up in residential water tanks. Redox reactions, triggered by influx of groundwater via wells into the residential water systems and leading to subtle changes in pH, are implicated in precipitation of Fe oxyhydroxides, oxidative scavenging of Ce(IV), and desorption and release of Pb into the residential water systems. The Pb isotope features in the residences and the region are best interpreted as reflecting a legacy of industrial Pb present in underlying aquifers that currently supply the drinking water wells.

Air-borne heavy metal contamination to dietary vegetables: a case study from India.

PubMed

Pandey, J; Pandey, Richa; Shubhashish, K

2009-12-01

Contamination of edible parts of three dietary vegetables, Spinach (Spinacia oleracea L.), Radish (Raphanus sativus L.), and Tomato (Lycopersicon esculentum Mill.) by air-borne cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) was determined using pot culture experiments at three sites in the city of Varanasi, India. The data revealed that although Cr and Cu in vegetables remained below their safe limits, about 68% of the total samples contained Cd, Ni, and Pb above their respective safe limits of 1.5, 1.5, and 2.5 μg g(-1). Site wise synchrony and air accumulation factor (AAF) indicated that atmospheric deposition was the main contributor of metal contamination to vegetables. The study suggests that if the present trends of atmospheric deposition are continued, air-borne heavy metals will contaminate the agricultural produce with long-term health implications.

Mercury contamination in Idaho bald eagles, Haliaeetus leucocephalus.

PubMed

Bechard, Marc J; Perkins, Dusty N; Kaltenecker, Gregory S; Alsup, Steve

2009-11-01

Because mercury contamination is potentially threatening to bald eagle (Haliaeetus leucocephalus) populations, we collected molted feathers at nests to determine the level of contamination in bald eagles in the state of Idaho, USA. Eagle feathers contained measurable amounts of cadmium (Cd), chromium (Cr), selenium (Se), lead (Pb), as well as mercury (Hg). Cadmium, Cr, Se, and Pb levels averaged 0.17, 4.68, 2.02, and 1.29 mg/kg dry weight, respectively, and were at or below concentrations indicated as causing reproductive failure in bald eagles. Mercury contamination was found to be the highest averaging 18.74 mg/kg dry weight. Although a concentration of only 7.5 mg/kg dry weight Hg in bird feathers can cause reduced productivity and even sterility, all of the eagles we sampled bred successfully and the population of bald eagles continues to grow annually throughout the state.

Magnesium Alleviates Adverse Effects of Lead on Growth, Photosynthesis, and Ultrastructural Alterations of Torreya grandis Seedlings.

PubMed

Shen, Jie; Song, Lili; Müller, Karin; Hu, Yuanyuan; Song, Yang; Yu, Weiwu; Wang, Hailong; Wu, Jiasheng

2016-01-01

Magnesium (Mg 2+ ) has been shown to reduce the physiological and biochemical stress in plants caused by heavy metals. To date our understanding of how Mg 2+ ameliorates the adverse effects of heavy metals in plants is scarce. The potential effect of Mg 2+ on lead (Pb 2+ ) toxicity in plants has not yet been studied. This study was designed to clarify the mechanism of Mg 2+ -induced alleviation of lead (Pb 2+ ) toxicity. Torreya grandis ( T. grandis ) seedlings were grown in substrate contaminated with 0, 700 and 1400 mg Pb 2+ per kg -1 and with or without the addition of 1040 mg kg -1 Mg 2+ . Growth parameters, concentrations of Pb 2+ and Mg 2+ in the plants' shoots and roots, photosynthetic pigment, gas exchange parameters, the maximum quantum efficiency (Fv/Fm), root oxidative activity, ultrastructure of chloroplasts and root growth were determined to analyze the effect of different Pb 2+ concentrations on the seedlings as well as the potential ameliorating effect of Mg 2+ on the Pb 2+ induced toxicity. All measurements were tested by a one-way ANOVA for the effects of treatments. The growth of T. grandis seedlings cultivated in soils treated with 1400 mg kg -1 Pb 2+ was significantly reduced compared with that of plants cultivated in soils treated with 0 or 700 mg kg -1 Pb 2+ . The addition of 1040 mg kg -1 Mg 2+ improved the growth of the Pb 2+ -stressed seedlings, which was accompanied by increased chlorophyll content, the net photosynthetic rate and Fv/Fm, and enhanced chloroplasts development. In addition, the application of Mg 2+ induced plants to accumulate five times higher concentrations of Pb 2+ in the roots and to absorb and translocate four times higher concentrations of Mg 2+ to the shoots than those without Mg 2+ application. Furthermore, Mg 2+ addition increased root growth and oxidative activity, and protected the root ultrastructure. To the best of our knowledge, our study is the first report on the mechanism of Mg 2+ -induced alleviation of Pb 2+ toxicity. The generated results may have important implications for understanding the physiological interactions between heavy metals and plants, and for successful management of T. grandis plantations grown on soils contaminated with Pb 2+ .

The persistent problem of lead poisoning in birds from ammunition and fishing tackle

USGS Publications Warehouse

Haig, Susan M.; D'Elia, Jesse; Eagles-Smith, Collin A.; Fair, Jeanne M.; Gervais, Jennifer; Herring, Garth; Rivers, James W.; Schulz, John H.

2014-01-01

Lead (Pb) is a metabolic poison that can negatively influence biological processes, leading to illness and mortality across a large spectrum of North American avifauna (>120 species) and other organisms. Pb poisoning can result from numerous sources, including ingestion of bullet fragments and shot pellets left in animal carcasses, spent ammunition left in the field, lost fishing tackle, Pb-based paints, large-scale mining, and Pb smelting activities. Although Pb shot has been banned for waterfowl hunting in the United States (since 1991) and Canada (since 1999), Pb exposure remains a problem for many avian species. Despite a large body of scientific literature on exposure to Pb and its toxicological effects on birds, controversy still exists regarding its impacts at a population level. We explore these issues and highlight areas in need of investigation: (1) variation in sensitivity to Pb exposure among bird species; (2) spatial extent and sources of Pb contamination in habitats in relation to bird exposure in those same locations; and (3) interactions between avian Pb exposure and other landscape-level stressors that synergistically affect bird demography. We explore multiple paths taken to reduce Pb exposure in birds that (1) recognize common ground among a range of affected interests; (2) have been applied at local to national scales; and (3) engage governmental agencies, interest groups, and professional societies to communicate the impacts of Pb ammunition and fishing tackle, and to describe approaches for reducing their availability to birds. As they have in previous times, users of fish and wildlife will play a key role in resolving the Pb poisoning issue.

High lead exposure and auditory sensory-neural function in Andean children.

PubMed Central

Counter, S A; Vahter, M; Laurell, G; Buchanan, L H; Ortega, F; Skerfving, S

1997-01-01

We investigated blood lead (B-Pb) and mercury (B-Hg) levels and auditory sensory-neural function in 62 Andean school children living in a Pb-contaminated area of Ecuador and 14 children in a neighboring gold mining area with no known Pb exposure. The median B-Pb level for 62 children in the Pb-exposed group was 52.6 micrograms/dl (range 9.9-110.0 micrograms/dl) compared with 6.4 micrograms/dl (range 3.9-12.0 micrograms/dl) for the children in the non-Pb exposed group; the differences were statistically significant (p < 0.001). Auditory thresholds for the Pb-exposed group were normal at the pure tone frequencies of 0.25-8 kHz over the entire range of B-Pb levels, Auditory brain stem response tests in seven children with high B-Pb levels showed normal absolute peak and interpeak latencies. The median B-Hg levels were 0.16 micrograms/dl (range 0.04-0.58 micrograms/dl) for children in the Pb-exposed group and 0.22 micrograms/dl (range 0.1-0.44 micrograms/dl) for children in the non-Pb exposed gold mining area, and showed no significant relationship to auditory function. Images Figure 1. Figure 3. A Figure 3. B PMID:9222138

The Environmentally Sound Aquaculture Strategies Based on Bioaccumulation of Heavy Metal of Lead (Pb) on Seaweed of Gracilaria verrucosa on Aquaculture Areas of MuararejaVillage, Tegal City

NASA Astrophysics Data System (ADS)

Nurjanah; Ambariyanto; Supriharyono; Yulianto, Bambang

2018-02-01

Community activities such as industry, trade, animal husbandry and agriculture and ssettlements resulting in heavy metals of lead (Pb) can be accumulated in water, sediment and seaweed Gracillaria verrucosa. It can contaminate ponds and affect aquaculture activities in Tegal. Seaweed Gracilaria verrucosa is afisheries commodity that has economical value and cultivated in the area of aquaculture MuararejaTegal. It can serve as fitoremedian that will help reduce the impact of heavy metal pollution due to its ability to accumulate pollutants. The objective of this study was to analyze bioaccumulation of heavy metals of lead (Pb) and its relationship with water quality management in order to develop seaweed cultivation of Gracillaria verrucosa in ponds in the area of aquaculture MuararejaTegal. The method used in this study is a survey, analysis of heavy metals of lead (Pb) in pond water, sediment and seaweed using Atomic Absorption Spectrophotometer (AAS) and the data were analyzed by descriptive quantitative. Bioconcentration of lead (Pb) during the dry season in pond water, sediment and seaweed Gracillaria verrucosa was measured from 0.003 to 0.025 ppm,5.543 to 23.699 ppm and 0.209 to 0.326 ppm respectively. While in the rainy season bioconcentration of lead (Pb) are from 0.003 to 0.015 ppm, sediment from 6.377 to 9.858 ppm and 0.209 to 0.326 ppm respectively. Bioconcentration of Pb in dry season was higher than in the rainy season and the biggest bioconcentration was found in the sediment pond waters. Pb bioaccumulation low and still below the quality standards of the Ministry of Environment decision 51 of 2004 so that the product is safe for consumption.

Combustion of a Pb(II)-loaded olive tree pruning used as biosorbent.

PubMed

Ronda, A; Della Zassa, M; Martín-Lara, M A; Calero, M; Canu, P

2016-05-05

The olive tree pruning is a specific agroindustrial waste that can be successfully used as adsorbent, to remove Pb(II) from contaminated wastewater. Its final incineration has been studied in a thermobalance and in a laboratory flow reactor. The study aims at evaluating the fate of Pb during combustion, at two different scales of investigation. The flow reactor can treat samples approximately 10(2) larger than the conventional TGA. A detailed characterization of the raw and Pb(II)-loaded waste, before and after combustion is presented, including analysis of gas and solids products. The Pb(II)-loaded olive tree pruning has been prepared by a previous biosorption step in a lead solution, reaching a concentration of lead of 2.3 wt%. Several characterizations of the ashes and the mass balances proved that after the combustion, all the lead presents in the waste remained in ashes. Combustion in a flow reactor produced results consistent with those obtained in the thermobalance. It is thus confirmed that the combustion of Pb(II)-loaded olive tree pruning is a viable option to use it after the biosorption process. The Pb contained in the solid remained in the ashes, preventing possible environmental hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

Oral lead bullet fragment exposure in northern bobwhite (Colinus virginianus).

PubMed

Kerr, Richard; Holladay, Jeremy; Holladay, Steven; Tannenbaum, Lawrence; Selcer, Barbara; Meldrum, Blair; Williams, Susan; Jarrett, Timothy; Gogal, Robert

2011-11-01

Lead (Pb) is a worldwide environmental contaminant known to adversely affect multiple organ systems in both mammalian and avian species. In birds, a common route of exposure is via oral ingestion of lead particles. Data are currently lacking for the retention and clearance of Pb bullet fragments in gastrointestinal (GI) tract of birds while linking toxicity with blood Pb levels. In the present study, northern bobwhite quail fed a seed-based diet were orally gavaged with Pb bullet fragments (zero, one or five fragments/bird) and evaluated for rate of fragment clearance, and changes in peripheral blood, renal, immune, and gastrointestinal parameters. Based on radiographs, the majority of the birds cleared or absorbed the fragments by seven days, with the exception of one five-fragment bird which took between 7 and 14 days. Blood Pb levels were higher in males than females, which may be related to egg production in females. In males but not females, feed consumption, body weight gain, packed cell volume (PCV), plasma protein concentration, and δ-aminolevulinic acid dehydratase (δ-ALAD) activity were all adversely affected by five Pb fragments. Birds of both sexes that received a single Pb fragment displayed depressed δ-ALAD, suggesting altered hematologic function, while all birds dosed with five bullet fragments exhibited greater morbidity.

Nanomechanical and electrical properties of Nb thin films deposited on Pb substrates by pulsed laser deposition as a new concept photocathode for superconductor cavities

NASA Astrophysics Data System (ADS)

Gontad, F.; Lorusso, A.; Panareo, M.; Monteduro, A. G.; Maruccio, G.; Broitman, E.; Perrone, A.

2015-12-01

We report a design of photocathode, which combines the good photoemissive properties of lead (Pb) and the advantages of superconducting performance of niobium (Nb) when installed into a superconducting radio-frequency gun. The new configuration is obtained by a coating of Nb thin film grown on a disk of Pb via pulsed laser deposition. The central emitting area of Pb is masked by a shield to avoid the Nb deposition. The nanomechanical properties of the Nb film, obtained through nanoindentation measurements, reveal a hardness of 2.8±0.3 GPa, while the study of the electrical resistivity of the film shows the appearance of the superconducting transitions at 9.3 K and 7.3 K for Nb and Pb, respectively, very close to the bulk material values. Additionally, morphological, structural and contamination studies of Nb thin film expose a very low droplet density on the substrate surface, a small polycrystalline orientation of the films and a low contamination level. These results, together with the acceptable Pb quantum efficiency of 2×10-5 found at 266 nm, demonstrate the potentiality of the new concept photocathode.

Assessing human health risks and strategies for phytoremediation in soils contaminated with As, Cd, Pb, and Zn by slag disposal.

PubMed

da Silva, William Ramos; da Silva, Fernando Bruno Vieira; Araújo, Paula Renata Muniz; do Nascimento, Clístenes Williams Araújo

2017-10-01

Soils impacted by metallurgy activities pose serious risks to the health of exposed populations, whether by ingestion of soil or contaminated food and water. The municipality of Santo Amaro, Bahia state, presents the most important case of human lead contamination in Brazil. It occurred because of inadequate slag disposal. The aims of this research were to: (i) determine the environmentally available concentrations and the distribution of As, Cd, Pb, and Zn in soil fractions; (ii) estimate the non-carcinogenic and carcinogenic risks of these elements for children; and (iii) to evaluate the use of corn (Zea mays) and castor bean (Ricinus communis) either for phytoextraction induced by chelating agents or phytostabilization. Our data demonstrated that the environmentally available concentrations of As, Cd, Pb, and Zn in soils surrounding the Pb smelting plant are among the highest that have been reported. Apart from Cd, sequential extraction demonstrated that most metals are in recalcitrant forms in the soil. However, the daily exposure of children to Pb, Zn, Cd, and As exceeded the acceptable daily intake as established by the World Health Organization. Non-carcinogenic risk modeling indicated probable adverse health effects from chronic exposure to soil Pb. The mean estimated time for remediation of the area using phytoextraction was high, ranging from 76 to 259 years; therefore, this is not a viable alternative for remediating soils in the studied area. However, good development in the contaminated soil along with restriction of the metal(oid) translocation to shoots enables castor bean to phytostabilize metal(oid)s. Additionally, castor bean cultivation may be an alternative for an economic return because of biofuel production. Copyright © 2017. Published by Elsevier Inc.

Effects of HMX-lead mixtures on reproduction of the earthworm Eisenia andrei.

PubMed

Savard, Kathleen; Berthelot, Yann; Auroy, Aurelie; Spear, Philip A; Trottier, Bertin; Robidoux, Pierre Yves

2007-10-01

High metal (e.g., Pb) concentrations are typically found in explosive-contaminated soil, and their presence may increase, decrease, or not influence toxicity predicted on the basis of one explosive alone (e.g., HMX). Nevertheless, few data are available in the scientific literature for this type of multiple exposure. Soil organisms, such as earthworms, are one of the first receptors affected by the contamination of soil. Therefore, a reproductive study was conducted using Eisenia andrei in a forest-type soil. Both HMX and Pb decreased reproduction parameters (number of total cocoons, hatched cocoons, and surviving juveniles) individually. Based on the total number of cocoons, HMX was more toxic in a forest soil than Pb, with EC(50) of 31 mg kg(-1), and 1068 mg kg(-1), respectively. The slope of the concentration-response curve was significantly greater in the case of Pb, which is consistent with the possibility that the two compounds do not act on the same target site. The response-addition model was used to predict the response of earthworms and to test for interaction between the two contaminants. The predicted toxicity was not significantly different than the observed toxicity, implying that Pb and HMX were considered noninteractive compounds. The combined action of Pb-HMX may be described, therefore, as dissimilar-noninteractive joint action in a forest soil. The results illustrate the relevance of considering the presence of metals in the risk assessment of explosive-contaminated sites because metals can add their toxicity to explosives. Extension of this study to other types of soil and other metals would improve the understanding of toxicity at these sites.

Effects of environmental lead contamination on cattle in a lead/zinc mining area: changes in cattle immune systems on exposure to lead in vivo and in vitro.

PubMed

Ikenaka, Yoshinori; Nakayama, Shouta M M; Muroya, Taro; Yabe, John; Konnai, Satoru; Darwish, Wageh Sobhy; Muzandu, Kaampwe; Choongo, Kennedy; Mainda, Geoffrey; Teraoka, Hiroki; Umemura, Takashi; Ishizuka, Mayumi

2012-10-01

The Republic of Zambia is rich in mineral resources, such as zinc (Zn) and lead (Pb), and mining is a key industry in Zambia. A previous study of Pb pollution in Kabwe, one of the main mining areas, found that soil was contaminated with high levels of toxic metals over a substantial area. In the present study, the authors focus on toxic metal pollution in cattle, one of the most important domestic animals in Zambia. Blood samples from cattle in Kabwe and a control area (Lusaka) were tested for toxic metal content. They also measured mRNA expression of metal-responsive proteins and cytokines in white blood cells using real-time reverse transcriptase polymerase chain reaction. In the present in vitro study, The authors cultured peripheral blood mononuclear cells (PBMCs) from cattle, exposing them to Pb acetate for 24 h and analyzing mRNA expression of metal-responsive proteins and selected cytokines. Lead concentrations in cattle blood from Kabwe were significantly greater than those from Lusaka, as were the mRNA expressions of metallothionein-2 (MT-2), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, and inducible nitric oxide synthase (iNOS). The present in vitro study demonstrated that Pb exposure led to an increase in the expressions of MT-2, TNF-α, IL-1β, and iNOS, similar to those found in vivo. These results indicate the possibility of immune system modulations in cattle from the Kabwe area. Copyright © 2012 SETAC.

Childhood lead poisoning from the smelter in Torreon, Mexico

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

Soto-Jimenez, Martin F., E-mail: martin@ola.icmyl.unam.mx; Flegal, Arthur R.

2011-05-15

Lead concentrations and isotopic compositions in blood samples of 34 children (ages 2-17 years) living within a 113 km{sup 2} area of a silver-zinc-lead smelter plant in Torreon, Mexico were compared to those of associated environmental samples (soil, aerosols, and outdoor and indoor dust) to identify the principal source(s) of environmental and human lead contamination in the area. Lead concentrations of soil and outdoor dust ranged 130-12,050 and 150-14,365 {mu}g g{sup -1}, respectively. Concentrations were greatest near the smelter, with the highest levels corresponding with the prevailing wind direction, and orders of magnitude above background concentrations of 7.3-33.3 {mu}g g{supmore » -1}. Atmospheric lead depositions in the city varied between 130 and 1350 {mu}g m{sup -2} d{sup -1}, again with highest rates <1 km from the smelter. Blood lead (PbB) concentrations (11.0{+-}5.3 {mu}g dl{sup -1}) levels in the children ranged 5.0-25.8 {mu}g dl{sup -1}, which is 3-14 times higher than the current average (1.9 {mu}g dl{sup -1}) of children (ages 1-5 years) in the US. Lead isotopic ratios ({sup 206}Pb/{sup 207}Pb, {sup 208}Pb/{sup 207}Pb) of the urban dust and soil (1.200{+-}0.009, 2.467{+-}0.003), aerosols (1.200{+-}0.002, 2.466{+-}0.002), and PbB (1.199{+-}0.001, 2.468{+-}0.002) were indistinguishable from each other, as well as those of the lead ores processed at the smelter (1.199{+-}0.007, 2.473{+-}0.007). Consequently, an elevated PbB concentrations of the children in Torreon, as well as in their environment, are still dominated by industrial emissions from the smelter located within the city, in spite of new controls on atmospheric releases from the facility. - Highlights: {yields} Pb contents in environmental samples evidenced chronic Pb pollution in Torreon. {yields} Pb stable isotopes evidenced contemporary emissions from the Ag-Cod-Pb-Zn smelter. {yields} Pb urban dust and soil account for most of the childhood lead poisoning in Torreon.{yields} Levels of Pub in Torreon's children are 3-14 times higher than children in the US.{yields} Children Pub concentrations are primarily attributed to emissions from the smelter.« less

Effect of dietary cadmium and/or lead on histopathological changes in the kidneys and liver of bank voles Myodes glareolus kept in different group densities.

PubMed

Salińska, Aneta; Włostowski, Tadeusz; Zambrzycka, Elżbieta

2012-11-01

Bank voles free living in a contaminated environment are known to be more sensitive to cadmium (Cd) toxicity than the rodents exposed to Cd under laboratory conditions, but the reasons for this difference are poorly defined. The present work was designed to determine whether dietary lead (Pb), a common environmental co-contaminant, and/or animal density that affects various physiological processes, would influence susceptibility to Cd toxicity in the kidneys and liver of these animals. For 6 weeks, the female bank voles were kept individually or in a group of six and provided with diet containing environmentally relevant concentrations of Cd [<0.1 μg/g (control) and 60 μg/g dry wt] and Pb [<0.2 μg/g (control) and 300 μg/g dry wt] alone or in combination. At the end of exposure period, histopathology and analyses of metallothionein, glutathione and zinc that are linked to a protective effect against Cd toxicity, as well as Cd, Pb, copper, iron and lipid peroxidation were carried out. Histopathological changes in the kidneys (a focal glomerular swelling and proximal tubule degeneration) and liver (a focal hepatocyte swelling, vacuolation and inflammation) occurred exclusively in some bank voles kept in a group and exposed to Cd alone (2/6) or Cd + Pb (4/6). The observed toxicity in grouped bank voles appeared not to be based on altered (1) tissue disposition of Cd and/or Pb, (2) metallothionein, glutathione and zinc concentrations, or (3) tissue copper, iron and lipid peroxidation. The data indicate that high population density in combination with environmental Pb may be responsible for an increased susceptibility to Cd toxicity observed in bank voles free living in a contaminated environment; the mechanism by which animal density affects Cd toxicity deserves further study.

Synthesis of hydrous zirconium oxide-impregnated chitosan beads and their application for removal of fluoride and lead

NASA Astrophysics Data System (ADS)

Cho, Dong-Wan; Jeon, Byong-Hun; Jeong, Yoojin; Nam, In-Hyun; Choi, Ui-Kyu; Kumar, Rahul; Song, Hocheol

2016-05-01

A composite adsorbent capable of simultaneous removal of both cationic and anionic contaminants from aqueous solutions was developed by impregnating hydrous zirconium oxide (HZO) into chitosan beads (CB). The optimal mass ratio of chitosan to HZO was 2:2. The composite adsorbent (HZOCB) had the rugged surface (52.74 m2 g-1) with irregular cracks caused by HZO inclusion and amine functional groups. The rate of Pb2+ adsorption by HZOCB was relatively rapid. Most of Pb2+ (89%) was adsorbed within 2.5 h. A binary sorbate system was noticeably favorable for F- adsorption as compared to single sorbate system. Adsorption of F- and Pb2+ followed pseudo-second order kinetics. The maximum sorption capacities obtained from Langmuir isotherm model were 22.1 and 222.2 mg g-1, respectively. The study demonstrates that the developed composite could be a potential adsorbent for the simultaneous remediation of F- and Pb2+ contamination in water.

Lead concentration in farmlands in southern Spain: Influence of the use of sewage sludge as fertilizer

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

Cabrera, C.; Gallego, C.; Lorenzo, M.L.

Lead content in soils is closely linked to the nature of the parent materials, although this relation can change or even disappear due to other factors involved in soil formation. In addition, soil Pb content is also affected by biogeochemical cycles. Soil pH is another factor that influences Pb levels; in general, this element is more mobile in acid than in alkaline soils, and tends to form residual concentrations in the latter. The distribution of Pb varies in soil horizons of different depths, and is more abundant in more superficial horizons. This accumulation depends not only on the composition ofmore » the soil, but also on atmospheric contamination and the proximity of heavily transited roads or other sources of exhaust products from motor vehicles. An additional source of pollution is Pb in pesticides, and in sewage sludges used as fertilizers in farmlands. Within the ecosystem, soils retain a portion of the products that are applied to them, and thus behave as a reservoir of toxic substances, including Pb. These deposits represent an important route through which toxins are incorporated into subterranean and surface bodies of water, into plant tissues and into the human food chain. In this study we determined the degree of Pb contamination in farmlands on the Mediterranean coast of the province of Granada in southern Spain. The area studied is intensively cropped, contains industries, heavily-travelled highways and many small towns. Pesticides, fertilizers, and sewage sludge recovered from industrial and urban wastes is used. Correlations between the presence of Pb in different samples and their proximity to potential sources of pollution were considered and the influence of sewage sludge as a source of Pb in soils was examined. In addition, the geochemical characteristics of the area, their influence on Pb fixation and retention, and Pb availability to nearby vegetation and groundwater tables were analysed.« less

Level and Contamination Assessment of Soil along an Expressway in an Ecologically Valuable Area in Central Poland

PubMed Central

Radziemska, Maja; Fronczyk, Joanna

2015-01-01

Express roads are a potential source of heavy metal contamination in the surrounding environment. The Warsaw Expressway (E30) is one of the busiest roads in the capital of Poland and cuts through the ecologically valuable area (Mazowiecki Natural Landscape Park). Soil samples were collected at distances of 0.5, 4.5 and 25 m from the expressway. The concentrations of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) were determined in the soils by the flame atomic absorption spectrometry method (FAAS). Soils located in the direct proximity of the analyzed stretch of road were found to have the highest values of pH and electrical conductivity (EC), which decreased along with an increase in the distance from the expressway. The contents of Cd, Cu and Zn were found to be higher than Polish national averages, whereas the average values of Ni and Pb were not exceeded. The pollution level was estimated based on the geo-accumulation index (Igeo), and the pollution index (PI). The results of Igeo and PI indexes revealed the following orders: Cu < Zn < Ni < Cd < Pb and Cu < Ni < Cd < Zn < Pb, and comparison with geochemical background values showed higher concentration of zinc, lead and cadmium. PMID:26512684

Level and Contamination Assessment of Soil along an Expressway in an Ecologically Valuable Area in Central Poland.

PubMed

Radziemska, Maja; Fronczyk, Joanna

2015-10-23

Express roads are a potential source of heavy metal contamination in the surrounding environment. The Warsaw Expressway (E30) is one of the busiest roads in the capital of Poland and cuts through the ecologically valuable area (Mazowiecki Natural Landscape Park). Soil samples were collected at distances of 0.5, 4.5 and 25 m from the expressway. The concentrations of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) were determined in the soils by the flame atomic absorption spectrometry method (FAAS). Soils located in the direct proximity of the analyzed stretch of road were found to have the highest values of pH and electrical conductivity (EC), which decreased along with an increase in the distance from the expressway. The contents of Cd, Cu and Zn were found to be higher than Polish national averages, whereas the average values of Ni and Pb were not exceeded. The pollution level was estimated based on the geo-accumulation index (Igeo), and the pollution index (PI). The results of Igeo and PI indexes revealed the following orders: Cu < Zn < Ni < Cd < Pb and Cu < Ni < Cd < Zn < Pb, and comparison with geochemical background values showed higher concentration of zinc, lead and cadmium.

Simultaneous immobilization of cadmium and lead in contaminated soils by hybrid bio-nanocomposites of fungal hyphae and nano-hydroxyapatites.

PubMed

Yang, Zhihui; Liang, Lifen; Yang, Weichun; Shi, Wei; Tong, Yunping; Chai, Liyuan; Gao, Shikang; Liao, Qi

2018-04-01

Self-aggregation of bulk nano-hydroxyapatites (n-HAPs) undermines their immobilization efficiencies of heavy metals in the contaminated soils. Here, the low-cost, easily obtained, and environment-friendly filamentous fungi have been introduced for the bio-matrices of the hybrid bio-nanocomposites to potentially solve such problem of n-HAPs. According to SEM, TEM, XRD, and FT-IR analyses, n-HAPs were successfully coated onto the fungal hyphae and their self-aggregation was improved. The immobilization efficiencies of diethylene-triamine-pentaacetic acid (DTPA)-extractable Cd and Pb in the contaminated soils by the bio-nanocomposites were individually one to four times of that by n-HAPs or the fungal hyphae. Moreover, the Aspergillus niger-based bio-nanocomposite (ANHP) was superior to the Penicillium Chrysogenum F1-based bio-nanocomposite (PCHP) in immobilization of Cd and Pb in the contaminated soils. In addition, the results of XRD showed that one of the potential mechanisms of metal immobilization by the hybrid bio-nanocomposites was dissolution of n-HAPs followed by precipitation of new metal phosphate minerals. Our results suggest that the hybrid bio-nanocomposite (ANHP) can be recognized as a promising soil amendment candidate for effective remediation on the soils simultaneously contaminated by Cd and Pb.

Phytoextraction of metals and rhizoremediation of PAHs in co-contaminated soil by co-planting of Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis).

PubMed

Wang, Kai; Huang, Huagang; Zhu, Zhiqiang; Li, Tingqiang; He, Zhenli; Yang, Xiaoe; Alva, Ashok

2013-01-01

A pot experiment was conducted to investigate the potential for phytoextraction of heavy metals and rhizoremediation of polycyclic aromatic hydrocarbons (PAHs) in co-contaminated soil by co-planting a cadmium/zinc (Cd/Zn) hyperaccumulator and lead (Pb) accumulator Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis). Co-planting with castor decreased the shoot biomass of S. alfredii as compared to that in monoculture. Cadmium concentration in S. alfredii shoot significantly decreased when grown with ryegrass or castor as compared to that in monoculture. However, no reduction of Zn or Pb concentration in S. alfredii shoot was detected in co-planting treatments. Total removal of either Cd, Zn, or Pb by plants was similar across S. alfredii monoculture or co-planting with ryegrass or castor, except enhanced Pb removal in S. alfredii and ryegrass co-planting treatment. Co-planting of S. alfredii with ryegrass or castor significantly enhanced the pyrene and anthracene dissipation as compared to that in the bare soil or S. alfredii monoculture. This appears to be due to the increased soil microbial population and activities in both co-planting treatments. Co-planting of S. alfredii with ryegrass or castor provides a promising strategy to mitigate both metal and PAH contaminants from co-contaminated soils.

Incidence of heavy metal contamination in water supplies in northern Mexico.

PubMed

Wyatt, C J; Fimbres, C; Romo, L; Méndez, R O; Grijalva, M

1998-02-01

Contaminants in drinking water present public health risks. The objective of this study was to analyze water samples taken from wells or storage tanks, direct sources for domestic water in Northern Mexico, for the presence of lead (Pb), copper (Cu), cadmium (Cd), arsenic (As), and mercury (Hg). The samples were analyzed by atomic absorption coupled with a hydride generator or a graphite furnace. High levels of Pb (0.05-0.12 ppm) were found in Hermosillo, Guaymas, and Nacozari. Forty-three percent of the samples in Sonora exceeded the action level (0.015 ppm) established by the EPA for Pb. For As, 8.92% exceeded the limit with a range of 0.002-0.305 ppm. Several studies have indicated a possible link between As and fluoride (F) in drinking water. This study showed a positive correlation between F and As (r = 0.53, P = 0.01, and n = 116). One location in Hermosillo had 7.36 ppm of F and 0.117 ppm of As, 3.5 times the recommended F levels in drinking water and 2 times higher than the level permitted for As. Hg contamination was found in 42% of the samples. Based on the results of this study, it appears that As, Hg, and Pb contamination in the drinking water for some areas of the state of Sonora is a major concern.

Economic incentive for applying vetiver grass to remediate lead, copper and zinc contaminated soils.

PubMed

Danh, Luu Thai; Truong, Paul; Mammucari, Raffaella; Fostert, Neil

2011-01-01

The application of vetiver grass (Chrysopogon zizaniodes) for phytoremediation of heavy metal contaminated soils can be promoted by economic return through essential oil production. Four levels of lead (0, 500, 2000, and 8000 mg kg(-1) dry soil), copper (0, 100, 400, and 1600 mg kg(-1) dry soil) and zinc (0, 400, 1600, and 6400 mg kg(-1) dry soil) were used to study their effects on vetiver growth, essential oil composition and yield. This study also investigated the effect of nitrogen concentrations on vetiver oil yield. Vetiver accumulated high concentrations of Pb, Cu and Zn in roots (3246, 754 and 2666 mg kg(-1), respectively) and small amounts of contaminants in shoots (327, 55, and 642 mg kg(-1), respectively). Oil content and yield were not affected at low and moderate concentrations of Cu and Zn. Only the application of Pb had a significant detrimental effect on oil composition. Extraction of vetiver essential oils by hydrodistillation produced heavy metal free products. High level of nitrogen reduced oil yields. Results show that phytoremediation of Cu and Zn contaminated soils by vetiver can generate revenue from the commercialization of oil extracts.

Chelant extraction of heavy metals from contaminated soils.

PubMed

Peters, R W

1999-04-23

The current state of the art regarding the use of chelating agents to extract heavy metal contaminants has been addressed. Results are presented for treatability studies conducted as worst-case and representative soils from Aberdeen Proving Ground's J-Field for extraction of copper (Cu), lead (Pb), and zinc (Zn). The particle size distribution characteristics of the soils determined from hydrometer tests are approximately 60% sand, 30% silt, and 10% clay. Sequential extractions were performed on the 'as-received' soils (worst case and representative) to determine the speciation of the metal forms. The technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound, and residual forms. The results indicated that most of the metals are in forms that are amenable to soil washing (i.e. exchangeable+carbonate+reducible oxides). The metals Cu, Pb, Zn, and Cr have greater than 70% of their distribution in forms amenable to soil washing techniques, while Cd, Mn, and Fe are somewhat less amenable to soil washing using chelant extraction. However, the concentrations of Cd and Mn are low in the contaminated soil. From the batch chelant extraction studies, ethylenediaminetetraacetic acid (EDTA), citric acid, and nitrilotriacetic acid (NTA) were all effective in removing copper, lead, and zinc from the J-Field soils. Due to NTA being a Class II carcinogen, it is not recommended for use in remediating contaminated soils. EDTA and citric acid appear to offer the greatest potential as chelating agents to use in soil washing the Aberdeen Proving Ground soils. The other chelating agents studied (gluconate, oxalate, Citranox, ammonium acetate, and phosphoric acid, along with pH-adjusted water) were generally ineffective in mobilizing the heavy metals from the soils. The chelant solution removes the heavy metals (Cd, Cu, Pb, Zn, Fe, Cr, As, and Hg) simultaneously. Using a multiple-stage batch extraction, the soil was successfully treated passing both the Toxicity Characteristics Leaching Procedure (TCLP) and EPA Total Extractable Metal Limit. The final residual Pb concentration was about 300 mg/kg, with a corresponding TCLP of 1.5 mg/l. Removal of the exchangeable and carbonate fractions for Cu and Zn was achieved during the first extraction stage, whereas it required two extraction stages for the same fractions for Pb. Removal of Pb, Cu, and Zn present as exchangeable, carbonates, and reducible oxides occurred between the fourth- and fifth-stage extractions. The overall removal of copper, lead, and zinc from the multiple-stage washing were 98.9%, 98.9%, and 97.2%, respectively. The concentration and operating conditions for the soil washing extractions were not necessarily optimized. If the conditions had been optimized and using a more representative Pb concentration (approximately 12000 mg/kg), it is likely that the TCLP and residual heavy metal soil concentrations could be achieved within two to three extractions. The results indicate that the J-Field contaminated soils can be successfully treated using a soil washing technique. Copyright 1999 Published by Elsevier Science B.V.

Lead poisoning in cattle and horses in the vicinity of a smelter

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

Hammond, P.B.; Aronson, A.L.

1964-01-01

An outbreak of lead poisoning near a smelter is described. Fatalities in horses and cattle occurred. Data presented concern the pattern and degree of contamination in animals and vegetation. The daily intake of approximately 6-7 mg. Pb/kg appears to be close to the minimum which eventually gives rise to signs of poisoning in cattle. Horses appear to be somewhat more susceptible. Even under conditions of chronic lead intake, the syndrome in cattle generally is acute or peracute. The concentration of lead in milk is linearly related to the concentration in blood cells at a ratio Pb cells/Pb milk of approximatelymore » 23. Evidence is presented indicating that relief of the burden of lead in tissues with EDTA therapy following chronic intake of the metal is a hazardous procedure. Data gathered by the Minnesota State Health Department during the episode indicate that people in the area and their water supply were not affected. 31 references.« less

Lead isotope ratios in six lake sediment cores from Japan Archipelago: Historical record of trans-boundary pollution sources.

PubMed

Hosono, Takahiro; Alvarez, Kelly; Kuwae, Michinobu

2016-07-15

Sediment cores from six lakes situated from north to south on the Japanese Archipelago were collected during 2009-2010 to investigate the hypothesis that deposition of lead (Pb) was coming from East Asia (including China, South Korea and eastern part of Russia). Accumulation rates and ages of the lake sediment were estimated by the (210)Pb constant rate of supply model and (137)Cs inputs to reconstruct the historical trends of Pb accumulation. Cores from four lakes located in the north and central Japan, showed clear evidence of Pb pollution with a change in the (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios in the recent sediment as compared to the deeper sediment. Among the six studied lakes, significant inputs of anthropogenic lead emissions were observed at Lake Mikazuki (north Hokkaido in north Japan), Lake Chokai (north of Honshu), and Lake Mikuriga (central part of Honshu). Pb isotopic comparison of collected core sediment and previously reported data for wet precipitation and aerosols from different Asian regions indicate that, before 1900, Pb accumulated in these three lakes was not affected by trans-boundary sources. Lake Mikazuki started to receive Pb emissions from Russia in early 1900s, and during the last two decades, this lake has been affected by trans-boundary Pb pollution from northern China. Lake Chokai has received Pb pollutant from northern China since early 1900s until 2009, whereas for the Lake Mikuriga the major Pb contaminant was transported from southern China during the past 100years. The results of our study demonstrate that Japan Archipelago has received trans-boundary Pb emissions from different parts of East Asian region depending on location, and the major source region has changed historically. Copyright © 2016 Elsevier B.V. All rights reserved.

Zinc and lead poisoning in wild birds in the tri-state mining district (Oklahoma, Kansas, and Missouri).

PubMed

Beyer, W N; Dalgarn, J; Dudding, S; French, J B; Mateo, R; Miesner, J; Sileo, L; Spann, J

2005-01-01

The Tri-State Mining District (Oklahoma, Kansas, and Missouri) is contaminated with Pb, Cd, and Zn from mining, milling and smelting. Metals have been dispersed heterogeneously throughout the District in the form of milled mine waste ("chat"), as flotation tailings and from smelters as aerial deposition or slag. This study was conducted to determine if the habitat has been contaminated to the extent that the assessment populations of wild birds are exposed to toxic concentrations of metals. American robins (Turdus migratorius), northern cardinals (Cardinalis cardinalis), and waterfowl had increased Pb tissue concentrations (p < 0.05) compared with Pb tissue concentrations from reference birds, and the exposure of songbirds to Pb was comparable with that of birds observed at other sites severely contaminated with Pb. Mean activities of the Pb-sensitive enzyme delta-aminolevulinic acid dehydratase (ALAD) were decreased by >50% in red blood cells in these birds (p < 0.05). Several birds had tissue concentrations of Pb that have been associated with impaired biological functions and external signs of poisoning. Cadmium was increased in kidneys of songbirds (p < 0.05), but no proximal tubule cell necrosis associated with Cd poisoning was observed. Zinc concentrations in liver and kidney of waterfowl were significantly higher (p < 0.05) than reference values. The increased environmental concentrations of Zn associated with mining in the District accounted for the pancreatitis previously observed in five waterfowl from the District. The District is the first site at which free-flying wild birds have been found to be suffering severe effects of Zn poisoning.

Positive matrix factorization as source apportionment of soil lead and cadmium around a battery plant (Changxing County, China).

PubMed

Xue, Jian-long; Zhi, Yu-you; Yang, Li-ping; Shi, Jia-chun; Zeng, Ling-zao; Wu, Lao-sheng

2014-06-01

Chemical compositions of soil samples are multivariate in nature and provide datasets suitable for the application of multivariate factor analytical techniques. One of the analytical techniques, the positive matrix factorization (PMF), uses a weighted least square by fitting the data matrix to determine the weights of the sources based on the error estimates of each data point. In this research, PMF was employed to apportion the sources of heavy metals in 104 soil samples taken within a 1-km radius of a lead battery plant contaminated site in Changxing County, Zhejiang Province, China. The site is heavily contaminated with high concentrations of lead (Pb) and cadmium (Cd). PMF successfully partitioned the variances into sources related to soil background, agronomic practices, and the lead battery plants combined with a geostatistical approach. It was estimated that the lead battery plants and the agronomic practices contributed 55.37 and 29.28%, respectively, for soil Pb of the total source. Soil Cd mainly came from the lead battery plants (65.92%), followed by the agronomic practices (21.65%), and soil parent materials (12.43%). This research indicates that PMF combined with geostatistics is a useful tool for source identification and apportionment.

Bioavailability of Pb and Zn from mine tailings as indicated by erythrocyte aminolevulinic acid dehydratase (ALA-D) activity in suckers (Pisces: catostomidae)

USGS Publications Warehouse

Schmitt, Christopher J.; Dwyer, F. James; Finger, Susan E.

1984-01-01

The activity of the erythrocyte enzyme δ-aminolevulinic acid dehydratase (ALA-D) was measured in 35 catostomids (black redhorse, Moxostoma duquesnei; golden redhorse, M. erythrurum; northern hogsucker, Hypentelium nigricans) collected from three sites on a stream contaminated with Pb-, Cd-, and Zn-rich mine tailings and from an uncontaminated site upstream. Enzyme activity was expressed in terms of hemoglobin (Hb), DNA, and protein concentrations; these variables can be determined in the laboratory on once-frozen blood samples. Concentrations of Pb and Zn in blood and of Pb in edible tissues were significantly higher, and ALA-D activity was significantly lower, at all three contaminated sites than upstream. At the most contaminated site, ALA-D activity was 62–67% lower than upstream. Lead concentrations in the edible tissues and in blood were positively correlated (r = 0.80), whereas ALA-D activity was negatively correlated with Pb in blood (r = −0.70) and in edible tissues (r = −0.59). Five statistically significant relations between Pb and Zn in blood and ALA-D activity were determined. The two models that explained the highest percentage (> 74%) of the total variance also included factors related to Hb concentration. All five significant models included negative coefficients for variables that represented Pb in blood and positive coefficients for Zn in blood. The ALA-D assay with results standardized to Hb concentration represents an expedient alternative to the more traditional hematocrit standardization, and the measurement of ALA-D activity by this method can be used to document exposure of fish to environmental Pb.

Treatment of lead contaminated water by a PVDF membrane that is modified by zirconium, phosphate and PVA.

PubMed

Zhao, Dandan; Yu, Yang; Chen, J Paul

2016-09-15

Lead contamination is one of the most serious problems in drinking water facing humans. In this study, a novel zirconium phosphate modified polyvinyl alcohol (PVA)-PVDF membrane was developed for lead removal. The zirconium ions and PVA were firstly coated onto a PVDF membrane through crosslinking reactions with glutaraldehyde, which was then modified by phosphate. The adsorption kinetics study showed that most of ultimate uptake occurred in 5 h. The adsorption increased with an increase in pH; the optimal adsorption was achieved at pH 5.5. The experimental data were better described by Langmuir equation than Freundlich equation; the maximum adsorption capacity was 121.2 mg-Pb/g at pH 5.5, much higher than other reported adsorptive membranes. The membrane exhibited a higher selectivity for lead over zinc with a relative selectivity coefficient (Pb(2+)/Zn(2+)) of 9.92. The filtration study showed that the membrane with an area of 12.56 cm(2) could treat 13.9 L (equivalent to 73,000 bed volumes) of lead containing wastewater with an influent concentration of 224.5 μ g/L to meet the maximum contaminant level of 15 μ g/L. It was demonstrated that the membrane did well in the removal of lead in both simulated wastewater and lead-spiked reservoir water and had a good reusability in its applications. The XPS studies revealed that the lead uptake was mainly due to cation exchange between hydrogen ions and lead ions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of mining-associated lead and zinc soil contamination on native floristic quality.

PubMed

Struckhoff, Matthew A; Stroh, Esther D; Grabner, Keith W

2013-04-15

We assessed the quality of plant communities across a range of lead (Pb) and zinc (Zn) soil concentrations at a variety of sites associated with Pb mining in southeast Missouri, USA. In a novel application, two standard floristic quality measures, Mean Coefficient of Conservatism (Mean C) and Floristic Quality Index (FQI), were examined in relation to concentrations of Pb and Zn, soil nutrients, and other soil characteristics. Nonmetric Multidimensional Scaling and Regression Tree Analyses identified soil Pb and Zn concentrations as primary explanatory variables for plant community composition and indicated negative relationships between soil metals concentrations and both Mean C and FQI. Univariate regression also demonstrated significant negative relationships between metals concentrations and floristic quality. The negative effects of metals in native soils with otherwise relatively undisturbed conditions indicate that elevated soil metals concentrations adversely affect native floristic quality where no other human disturbance is evident. Published by Elsevier Ltd.

Effects of mining-associated lead and zinc soil contamination on native floristic quality

USGS Publications Warehouse

Struckhoff, Matthew A.; Stroh, Esther D.; Grabner, Keith W.

2013-01-01

We assessed the quality of plant communities across a range of lead (Pb) and zinc (Zn) soil concentrations at a variety of sites associated with Pb mining in southeast Missouri, USA. In a novel application, two standard floristic quality measures, Mean Coefficient of Conservatism (Mean C) and Floristic Quality Index (FQI), were examined in relation to concentrations of Pb and Zn, soil nutrients, and other soil characteristics. Nonmetric Multidimensional Scaling and Regression Tree Analyses identified soil Pb and Zn concentrations as primary explanatory variables for plant community composition and indicated negative relationships between soil metals concentrations and both Mean C and FQI. Univariate regression also demonstrated significant negative relationships between metals concentrations and floristic quality. The negative effects of metals in native soils with otherwise relatively undisturbed conditions indicate that elevated soil metals concentrations adversely affect native floristic quality where no other human disturbance is evident.

Integrated micro-biochemical approach for phytoremediation of cadmium and lead contaminated soils using Gladiolus grandiflorus L cut flower.

PubMed

Mani, Dinesh; Kumar, Chitranjan; Patel, Niraj Kumar

2016-02-01

The potential of vermicompost, elemental sulphur, Thiobacillus thiooxidans and Pseudomonas putida for phytoremediation is well known individually but their integrated approach has not been discovered so far. The present work highlights the consideration of so far overlooked aspects of their integrated treatment by growing the ornamental plant, Gladiolus grandiflorus L in uncontaminated and sewage-contaminated soils (sulphur-deficient alluvial Entisols, pH 7.6-7.8) for phytoremediation of cadmium and lead under pot experiment. Between vermicompost and elemental sulphur, the response of vermicompost was higher towards improvement in the biometric parameters of plants, whereas the response of elemental sulphur was higher towards enhanced bioaccumulation of heavy metals under soils. The integrated treatment (T7: vermicompost 6g and elemental sulphur 0.5gkg(-1) soil and co-inoculation of the plant with T. thiooxidans and P. putida) was found superior in promoting root length, plant height and dry biomass of the plant. The treatment T7 caused enhanced accumulation of Cd up to 6.96 and 6.45mgkg(-1) and Pb up to 22.6 and 19.9mgkg(-1) in corm and shoot, respectively at the contaminated soil. T7 showed maximum remediation efficiency of 0.46% and 0.19% and bioaccumulation factor of 2.92 and 1.21 and uptake of 6.75 and 21.4mgkg(-1) dry biomass for Cd and Pb respectively in the contaminated soil. The integrated treatment T7 was found significant over the individual treatments to promote plant growth and enhance phytoremediation. Hence, authors conclude to integrate vermicompost, elemental sulphur and microbial co-inoculation for the enhanced clean-up of Cd and Pb-contaminated soils. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of lime on lead uptake by five plant species

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

Cox, W.J.; Rains, D.W.

1972-01-01

Liming at 0, 2.2, and 4.4 tons/hectare (0, 1, and 2 English tons/acre) was tested as a means of reducing Pb uptake by five species from two Pb contaminated soils. The soils represent the 0- to 10- and 10- to 30-cm horizons of Los Osos clay loam (a Typic Argixeroll) and contained 94 +/- 18 and 32 +/- 7 ppm Pb, respectively. There was no effect of lime on yield, but Pb concentrations in tops were reduced. At all times of harvest and lime rates the Pb concentration followed the series Glycine max L. much greater than Trifolium subterraneum L.more » > Zea mays L. = Avena sativa L. = Triticum aestivum L. 10 references, 2 figures, 3 tables.« less

[Parameters optimization and cleaning efficiency evaluation of attrition scrubbing remediation of Pb-contaminated soil].

PubMed

Yang, Wen; Huang, Jin-lou; Peng, Hui-qing; Li, Si-tuo

2013-09-01

Attrition scrubbing was used to remediate lead contaminated-site soil, and the main purpose was to remove fine particles and lead contaminants from the surface of sand. The optimal parameters of attrition scrubbing were determined by orthogonal experiment, and three soil samples with different lead concentration were subjected to attrition scrubbing experiments. The results showed that the optimal scrubbing parameters were: a solid ratio of 70% dry matter, a temperature of 25 degrees C, an attrition time of 30 min, and an attrition speed of 1200 r x min(-1). Before attrition scrubbing, the screening and analysis of soil showed that in all three soil samples, lead was mainly enriched on sand and fine particles, and the distribution of lead was highly correlated to the organic matter. After attrition scrubbing, the washing efficiency of the original state lead contaminated sand soil in triplicates was 67.61%, 31.71% and 41.01%, respectively, which indicates that attrition scrubbing can remove part of the fine soil and lead contaminants from the surface of sand, to accomplish the purpose of pollutants enrichment. Scanning electron microscopy (SEM) analysis showed that the sand surface became smooth after attrition scrubbing. The results above show that attrition scrubbing has a good washing effect for the remediation of lead contaminated sand soil.

Size-resolved dust and aerosol contaminants associated with copper and lead smelting emissions: implications for emission management and human health.

PubMed

Csavina, Janae; Taylor, Mark P; Félix, Omar; Rine, Kyle P; Eduardo Sáez, A; Betterton, Eric A

2014-09-15

Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb and other potentially toxic elements. In this work, we show that size-resolved concentrations of As and Pb generally follow a bimodal distribution with the majority of contaminants in the fine size fraction (<1 μm) around mining activities that include smelting operations at various sites in Australia and Arizona. This evidence suggests that contaminated fine particles (<1 μm) are the result of vapor condensation and coagulation from smelting operations while coarse particles are most likely the result of windblown dust from contaminated mine tailings and fugitive emissions from crushing and grinding activities. These results on the size distribution of contaminants around mining operations are reported to demonstrate the ubiquitous nature of this phenomenon so that more effective emission management and practices that minimize health risks associated with metal extraction and processing can be developed. Copyright © 2014 Elsevier B.V. All rights reserved.

Lead toxicity in Brassica pekinensis Rupr.: effect on nitrate assimilation and growth.

PubMed

Xiong, Zhi-Ting; Zhao, Fei; Li, Min-jing

2006-04-01

Lead is a major heavy-metal contaminant in the environment that has various anthropogenic and natural sources. To study the phytotoxic effects of Pb on the popular vegetable Chinese cabbage (Brassica pekinensis Rupr.) via depression of nitrogen assimilation, pot culture experiments with three concentrations of treatment with Pb (0, 4, and 8 mmol/kg dry soil) were carried out. Our results demonstrated adverse effects of Pb on nitrogen assimilation and plant growth. The addition of Pb in the soil resulted in elevated accumulation of Pb in the shoots of the plants: Pb concentrations of 14.3, 202.3, and 418.2 mg/kg (DW) in the shoots were detected with the 0, 4, and 8 mmol/kg treatments, respectively. Compared to the control, Pb exposure (4 and 8 mmol/kg) significantly decreased shoot nitrate content (71% and 80% of the control), nitrate reductase activity (104% and 49% of the control), and free amino acid content (81% and 82% of the control), indicating decreased nitrogen assimilation in the plants. The effect of Pb also was shown by the progressive decline in shoot biomass with increasing Pb concentration in plant shoots and in the soil. However, at the treatment levels used in this study, lead did not induce visible toxic symptoms. The lowest-concentration Pb treatment (4 mmol/kg) stimulated chlorophyll b content but did not influence chlorophyll a content. The results suggested that the toxicity of Pb to the plants occurred at least partly via depression of nitrogen assimilation. Copyright 2006 Wiley Periodicals, Inc.

Compound washing remediation and response surface analysis of lead-contaminated soil in mining area by fermentation broth and saponin.

PubMed

Zhang, Hongjiao; Wang, Zhengwei; Gao, Yuntao

2018-03-01

The development of eluent is the key to soil washing remediation, and a compound eluent was constructed using the prepared citric acid fermentation broth and saponin in this study. It displayed a good washing performance for Pb, Cu, Cr, and Cd in red soil, and the removal rates, especially Pb, gained an improvement compared with a single eluent. Based on this, the compound eluent was applied to remediation of Pb-contaminated soil in mining area; the desorption of Pb is a heterogeneous diffusion process, and Pb in large particle size soil is relatively easy to remove. An available response surface analysis model was established; its P < 0.0001 is very significant, and the P of the missing item is 0.1152. The degree of influence of three significant factors on removal of Pb is liquid-to-solid ratio > washing time > saponin concentration, and liquid-to-solid ratio and washing time show interaction. Moreover, the Pb removal rate can reach 56.20% under the optimized conditions: 0.25% saponin concentration, 20 mL/g liquid-to-solid ratio, and 320-min washing time, which is close to the predicted value of 56.20% with a difference of 1.41%. In addition, most of the active Pb was removed and environmental risks were lowered after washing.

The impact of auxins used in assisted phytoextraction of metals from the contaminated environment on the alterations caused by lead(II) ions in the organization of model lipid membranes.

PubMed

Hąc-Wydro, Katarzyna; Sroka, Aleksandra; Jabłońska, Klaudia

2016-07-01

Auxins are successfully used to improve phytoextraction efficiency of metal ions from the contaminated environment, however, the mechanism of their activity in this field is not explained. Auxins are known to exert various biochemical alterations in the plant membranes and cells, but their activity involves also direct interactions with lipids leading to changes in membrane organization. Following the suggestion that the auxins-induced modifications in membrane properties alleviate toxic effect of metal ions in this paper we have undertaken the comparative studies on the effect of metal ions and metal ions/auxins mixtures on model membrane systems. The experiments were done on lipid monolayers differing in their composition spread on water subphase and on Pb(2+), Indole-3-acetic acid (IAA), 1-Naphthaleneacetic acid (NAA) and Pb(2+)/IAA and Pb(2+)/NAA water solutions. The analysis of the collected data suggests that metal ions and auxins can change fluidity of the lipid systems and weaken the interactions between monolayer components. This manifested in the increase of the mean area per molecule and the excess area per molecule values for the films on Pb(2+), auxins as well as Pb(2+)/auxin solutions as compared to the values on pure water subphase. However, the presence of auxin in the mixture with lead(II) ions makes the alterations induced by sole metal ions weaker. This effect was more pronounced for the membranes of a higher packing. Thus it was proposed that auxins may enhance phytoextraction of metal ions by weakening their destabilizing effect on membrane. Copyright © 2016 Elsevier B.V. All rights reserved.

Enhanced removal of lead from contaminated soil by polyol-based deep eutectic solvents and saponin

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Soumyadeep; Mukherjee, Sumona; Hayyan, Adeeb; Hayyan, Maan; Hashim, Mohd Ali; Sen Gupta, Bhaskar

2016-11-01

Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.g. glycerol and ethylene glycol. A natural surfactant saponin obtained from soapnut fruit pericarp, was mixed with DESs to boost their efficiency. The DESs on their own did not perform satisfactory due to higher pH; however, they improved the performance of soapnut by up to 100%. Pb removal from contaminated soil using mixture of 40% DES-Gly and 1% saponin and mixture of 10% DES-Gly and 2% saponin were above 72% XRD and SEM studies did not detect any major corrosion in the soil texture. The environmental friendliness of both DESs and saponin and their affordable costs merit thorough investigation of their potential as soil washing agents.

Phytoaccumulation of lead by sunflower (Helianthus annuus), tobacco (Nicotiana tabacum), and vetiver (Vetiveria zizanioides).

PubMed

Boonyapookana, Benjaporn; Parkpian, Preeda; Techapinyawat, Sombun; DeLaune, R D; Jugsujinda, Aroon

2005-01-01

The ability of three plant species: Helianthus annuus, Nicotiana tabacum, and Vetiveria zizanioides for phytoaccumulation of Pb was studied. Plants were grown in hydroponic solution containing Pb(NO3)2 at concentration of 0.25 and 2.5 mM Pb in the presence or absence of chelating agents (EDTA or DTPA). Lead (Pb) transport and localization within the tissues of the plant species was determined using scanning electron microscope equipped with energy dispersive X-ray spectrometers (SEM-EDS). The addition of chelators increased Pb uptake as compared to plants grown in solution containing Pb alone. Lead taken up by the plant species were concentrated in both leaf and stem at the region of vascular bundles with greater amounts in the leaf portion. Lead granules were also found in the H. annuus root tissue from the epidermis layer to the central axis. After four weeks of growth a 23-fold increase in shoot Pb content for H. annuus and N. tabacum and 17-fold increase in shoot Pb for V. zizanioides resulted from plants grown in the 2.5 mM Pb-EDTA treatment. The higher Pb treatment (2.5 mM Pb containing EDTA) resulted in higher concentrations of Pb in plant tissue at the fourth week of exposure as compared to Pb treatment containing DTPA. Overall, Pb accumulation potential of H. annuus was greater than that of N. tabacum and V. zizanioides as indicated by the bioconcentration factor (171, 70, and 88, respectively). The highest measured Pb concentrations were found in H. annuus roots, stems, and leaves (2668, 843, and 3611 microg/g DW, respectively) grown in the 2.5 mM Pb-EDTA treatment. The addition of chelators caused some reduction in plant growth and biomass. Results showed that the three plant species tested have potential for use in phytoaccumulation of Pb since the Pb was concentrated in leaf and stem as compared to control plants. H. annuus however best meet the prerequisites for a hyperaccumulator plant and would have the potential for use in the restoration of abandoned mines and factories sites contaminated with elevated Pb levels in the soil.

Lead in Martian Meteorites-- Observations and Inconsistencies: I. Chassigny

NASA Technical Reports Server (NTRS)

Jones, J. H.; Simon, J. I.; Usui, T.

2017-01-01

The history of Pb isotope analyses of the martian meteorites (SNC) and their interpretations is laden with difficulties. Two different analytical groups have interpreted their ancient (= 4 Ga) shergottite Pb ages as primary [1-5]. A Nakhla age of approximately 4.3 Ga has been interpreted to be primary as well [2]. This is in stark contrast to the young (= 1.4 Ga) crystallization ages defined by the Rb-Sr, Sm-Nd, Lu-Hf, and KAr systems [6]. Possibly, a better interpretation for the ancient Pb ages is that they reflect the formation times of the various SNC source regions [7]. A difficulty in dealing with Pb is that terrestrial contamination is ubiquitous, unlike the other chronometer systems noted above. This issue is complicated by the fact that radioactive decay causes localized mineral damage. So washing and leaching to remove Pb contamination tends to remove in situ radiogenic Pb. This issue is further compounded because U and Th are often concentrated in phosphates and other minor phases, so the leaching process tends to remove these, especially phosphates. Another difficulty is that it is not clear whether the observed Pb isotopic variation in leachates, residues, and ion-microprobe analyses is due to terrestrial or to indigenous martian Pb contamination [e.g., 8]. A third difficulty is that the shergottites on the one hand, and the nakhlites and chassignites on the other, appear to have come from separate source regions with different chemical compositions [e.g., 7]. Thus, it is expected that their Pb isotopic characteristics would be different. And even if all these meteorite types came from the same source region, their igneous ages differ considerably. The nakhlites and chassignites are 1.4 Ga and the shergottites are = 600 Ma [e.g., 6]. This age difference alone should assure that the two distinct SNC groups have differing Pb isotopic signatures.

Trace elements and Pb isotopes in soils and sediments impacted by uranium mining.

PubMed

Cuvier, A; Pourcelot, L; Probst, A; Prunier, J; Le Roux, G

2016-10-01

The purpose of this study is to evaluate the contamination in As, Ba, Co, Cu, Mn, Ni, Sr, V, Zn and REE, in a high uranium activity (up to 21,000Bq∙kg(-1)) area, downstream of a former uranium mine. Different geochemical proxies like enrichment factor and fractions from a sequential extraction procedure are used to evaluate the level of contamination, the mobility and the availability of the potential contaminants. Pb isotope ratios are determined in the total samples and in the sequential leachates to identify the sources of the contaminants and to determine the mobility of radiogenic Pb in the context of uranium mining. In spite of the large uranium contamination measured in the soils and the sediments (EF≫40), trace element contamination is low to moderate (2

Identification of 210Pb and 210Po in the bulk of copper samples with a low-background alpha particle counter

NASA Astrophysics Data System (ADS)

Abe, K.; Hiraide, K.; Ichimura, K.; Kishimoto, Y.; Kobayashi, K.; Kobayashi, M.; Moriyama, S.; Nakahata, M.; Norita, T.; Ogawa, H.; Sato, K.; Sekiya, H.; Takachio, O.; Takeda, A.; Tasaka, S.; Yamashita, M.; Yang, B. S.; Kim, N. Y.; Kim, Y. D.; Itow, Y.; Kanzawa, K.; Kegasa, R.; Masuda, K.; Takiya, H.; Fushimi, K.; Kanzaki, G.; Martens, K.; Suzuki, Y.; Xu, B. D.; Fujita, R.; Hosokawa, K.; Miuchi, K.; Oka, N.; Takeuchi, Y.; Kim, Y. H.; Lee, K. B.; Lee, M. K.; Fukuda, Y.; Miyasaka, M.; Nishijima, K.; Nakamura, S.

2018-03-01

We established a method to assay 210Pb and 210Po contaminations in the bulk of copper samples using a low-background alpha particle counter. The achieved sensitivity for the 210Pb and 210Po contaminations reaches a few mBq/kg. Due to this high sensitivity, the 210Pb and 210Po contaminations in oxygen free copper bulk were identified and measured for the first time. The 210Pb contaminations of our oxygen free copper samples were 17-40 mBq/kg. Based on our investigation of copper samples in each production step, the 210Pb in oxygen free copper was understood to be a small residual of an electrolysis process. This method to measure bulk contaminations of 210Pb and 210Po could be applied to other materials.

Identification of 210Pb and 210Po in the bulk of copper samples with a low-background alpha particle counter

NASA Astrophysics Data System (ADS)

Kobayashi, Kazuyoshi

2018-01-01

We established a method to assay 210Pb and 210Po contaminations in the bulk of copper samples using a low-background alpha particle counter. The achieved sensitivity for the 210Pb and 210Po contaminations reaches a few mBq/kg. Due to this high sensitivity, the 210Pb and 210Po contaminations in oxygen free copper bulk were identified and measured for the first time. The 210Pb contaminations of our oxygen free copper samples were 17-40 mBq/kg. Based on our investigation of copper samples in each production step, the 210Pb in oxygen free copper was understood to be a small residual of an electrolysis process. This method to measure bulk contaminations of 210Pb and 210Po could be applied to other materials.

Silica nanoparticles capture atmospheric lead: implications in the treatment of environmental heavy metal pollution.

PubMed

Yang, Xifei; Shen, Zhiguo; Zhang, Bing; Yang, Jianping; Hong, Wen-Xu; Zhuang, Zhixiong; Liu, Jianjun

2013-01-01

Lead (Pb) contamination in the air is a severe global problem, most notably in China. Removal of Pb from polluted air remains a significant challenge. It is unclear what potential effects silica nanoparticles (SiNPs) exposure can have on atmospheric Pb. Here we first characterized the features of SiNPs by measuring the particle size, zeta potential and the specific surface area of SiO(2) particles using a Nicomp 380/ZLS submicron particle sizer, the Brunauer-Emmett-Teller (BET) method and transmission electronic microscopy (TEM). We measured the content of the metal Pb adsorbed by SiNPs exposed to two Pb polluted electric battery plants using inductively coupled plasma mass spectrometry (ICP-MS). It is found that SiNPs exposed to two Pb polluted electric battery plants absorb more atmospheric Pb compared to either blank control or micro-sized SiO(2) particles in a time-dependent manner. This is the first study demonstrating that SiNPs exposure can absorb atmospheric Pb in the polluted environment. These novel findings indicate that SiNPs have potential to serve as a significant adsorbent of Pb from industrial pollution, implicating a potentially novel application of SiNPs in the treatment of environmental heavy metal pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

Lead accumulation and tolerance of Moso bamboo (Phyllostachys pubescens) seedlings: applications of phytoremediation*

PubMed Central

Liu, Dan; Li, Song; Islam, Ejazul; Chen, Jun-ren; Wu, Jia-sen; Ye, Zheng-qian; Peng, Dan-li; Yan, Wen-bo; Lu, Kou-ping

2015-01-01

A hydroponics experiment was aimed at identifying the lead (Pb) tolerance and phytoremediation potential of Moso bamboo (Phyllostachys pubescens) seedlings grown under different Pb treatments. Experimental results indicated that at the highest Pb concentration (400 μmol/L), the growth of bamboo seedlings was inhibited and Pb concentrations in leaves, stems, and roots reached the maximum of 148.8, 482.2, and 4282.8 mg/kg, respectively. Scanning electron microscopy revealed that the excessive Pb caused decreased stomatal opening, formation of abundant inclusions in roots, and just a few inclusions in stems. The ultrastructural analysis using transmission electron microscopy revealed that the addition of excessive Pb caused abnormally shaped chloroplasts, disappearance of endoplasmic reticulum, shrinkage of nucleus and nucleolus, and loss of thylakoid membranes. Although ultrastructural analysis revealed some internal damage, even the plants exposed to 400 μmol/L Pb survived and no visual Pb toxicity symptoms such as necrosis and chlorosis were observed in these plants. Even at the highest Pb treatment, no significant difference was observed for the dry weight of stem compared with controls. It is suggested that use of Moso bamboo as an experimental material provides a new perspective for remediation of heavy metal contaminated soil owing to its high metal tolerance and greater biomass. PMID:25644467

Investigation of lead bioimmobilization and transformation by Penicillium oxalicum SL2.

PubMed

Ye, Binhui; Luo, Yating; He, Junyu; Sun, Lijuan; Long, Bibo; Liu, Qinglin; Yuan, Xiaofeng; Dai, Peibin; Shi, Jiyan

2018-05-18

Fungi Penicillium oxalicum SL2 was applied for Pb 2+ bioremediation in aqueous solution in this study. After 7 days of incubation at different initial concentrations of Pb 2+ (0, 100, 500 and 2500 mg L -1 ), most of Pb 2+ were removed (90, 98.3, and 86.2%), the maximum Pb content in mycelium reached about 155.6 mg g -1  dw. Meanwhile, the formation of extracellular secondary minerals and intracellular Pb-complex were observed and identified, the speciation of Pb in mycelium was also detected by X-ray absorption near-edge structure (XANES) spectroscopy, i.e., Pb-oxalate, Pb-citrate, Pb-hydrogen phosphate and Pb-glutathione analogues. In addition, content of glutathione and oxidized glutathione was increased under the exposure of Pb 2+ , which implied that glutathione might play a key role in Pb immobilization and detoxification in P. oxalicum SL2. This study elucidated partial mechanisms of Pb immobilization and speciation transformation of this strain, providing an alternative biomaterial in the bioremediation of Pb-contaminated wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Induction of lead-binding phytochelatins in vetiver grass [Vetiveria zizanioides (L.)].

PubMed

Andra, Syam S; Datta, Rupali; Sarkar, Dibyendu; Makris, Konstantinos C; Mullens, Conor P; Sahi, Shivendra V; Bach, Stephan B H

2009-01-01

Elevated lead (Pb) concentrations in residential houseyards around house walls painted with Pb-based pigments pose serious human health risks, especially to children. Vetiver grass (Vetiveria zizanioides L.) has shown promise for use in in situ Pb phytoremediation efforts. However, little is known about the biochemical mechanisms responsible for the observed high Pb tolerance by vetiver. We hypothesized that vetiver exposure to Pb induced the synthesis of phytochelatins (PC(n)) and the formation of Pb-PC(n) complexes, alleviating the phytotoxic effects of free Pb ions. Our main objective was to identify PC(n) and Pb-PC(n) complexes in root and shoot compartments of vetiver grass using high-performance liquid chromatography coupled to electrospray mass spectrometry (HPLC-ES-MS). After 7 d of exposure to Pb, vetiver accumulated up to 3000 mg Pb kg(-1) in shoot tissues, but much higher Pb concentrations were measured in root ( approximately 20,000 mg kg(-1)), without phytotoxic symptoms. Scanning electron micrographs showed Pb deposition in the vascular tissues of root and shoot, suggesting Pb translocation to shoot. Collision-induced dissociation analyses in MS/ MS mode during HPLC-ES-MS analysis allowed for the confirmation of four unique PC(n) (n = 1-4) based on their respective amino acid sequence. The high tolerance of vetiver grass to Pb was attributed to the formation of PC(n) and Pb-PC(n) complexes within the plant tissues, using ES-MS and Pb mass isotopic patterns. These data illustrate the mechanism of high Pb tolerance by vetiver grass, suggesting its potential usefulness for the remediation of Pb-contaminated residential sites.

In Vitro and In Vivo Evaluation of Lactobacillus delbrueckii subsp. bulgaricus KLDS1.0207 for the Alleviative Effect on Lead Toxicity

PubMed Central

Li, Bailiang; Jin, Da; Yu, Shangfu; Etareri Evivie, Smith; Muhammad, Zafarullah; Huo, Guicheng; Liu, Fei

2017-01-01

Lead (Pb) is a toxic contaminating heavy metal that can cause a variety of hazardous effects to both humans and animals. In the present study, Lactobacillus delbrueckii subsp. bulgaricus KLDS1.0207 (L. bulgaricus KLDS1.0207), which has a remarkable Pb binding capacity and Pb tolerance, was selected for further study. It was observed that the thermodynamic and kinetic model of L. bulgaricus KLDS1.0207 Pb binding respectively fit with the Langmuir–Freundlich model and the pseudo second-order kinetic model. Scanning electron microscopy and energy dispersive spectroscopy analysis disclosed that the cell surfaces were covered with Pb and that carbon and oxygen elements were chiefly involved in Pb binding. Combined with Fourier transform infrared spectroscopy analysis, it was revealed that the carboxyl, phosphoryl, hydroxyl, amino and amide groups were the main functional groups involved in the Pb adsorption. The protective effects of L. bulgaricus KLDS1.0207 against acute Pb toxicity in mice was evaluated by prevention and therapy groups, the results in vivo showed that L. bulgaricus KLDS1.0207 treatment could reduce mortality rates, effectively increase Pb levels in the feces, alleviate tissue Pb enrichment, improve the antioxidant index in the liver and kidney, and relieve renal pathological damage. Our findings show that L. bulgaricus KLDS1.0207 can be used as a potential probiotic against acute Pb toxicity. PMID:28786945

Size-resolved Pb distribution in the Athabasca River shows snowmelt in the bituminous sands region an insignificant source of dissolved Pb

NASA Astrophysics Data System (ADS)

Javed, Muhammad Babar; Cuss, Chad W.; Grant-Weaver, Iain; Shotyk, William

2017-03-01

Lead (Pb) is a metal of special importance because of its long history of commercial and industrial use, global atmospheric contamination accelerated by the use of gasoline additives, and health effects, with children being especially vulnerable. Global atmospheric Pb pollution reached its zenith in the 1970’s, but subsequent impacts on freshwater aquatic systems are poorly understood. Employing metal-free sampling and handling protocols, we show that snowmelt from the Athabasca bituminous sands region is an insignificant source of dissolved Pb to the Athabasca River (AR). Total Pb in the AR is low, and almost entirely in particulate form. Lead in the suspended solids in the AR exactly follows thorium (Th), a conservative lithophile element, and a linear regression of Pb against Th (Pb = 1.6 × Th + 0.0 R2 = 0.99) yields a slope identical to the Pb/Th ratio in the Upper Continental Crust. In the “dissolved” fraction, the Pb/Th ratio is equivalent to that of deep, open ocean seawater; and dominated by colloidal forms. Taken together, these results show that the efforts of recent decades to reduce anthropogenic Pb to the environment have been successful: Pb loading to the river can now be explained predominantly by natural processes, namely erosion plus chemical weathering.

In Vitro and In Vivo Evaluation of Lactobacillus delbrueckii subsp. bulgaricus KLDS1.0207 for the Alleviative Effect on Lead Toxicity.

PubMed

Li, Bailiang; Jin, Da; Yu, Shangfu; Etareri Evivie, Smith; Muhammad, Zafarullah; Huo, Guicheng; Liu, Fei

2017-08-08

Lead (Pb) is a toxic contaminating heavy metal that can cause a variety of hazardous effects to both humans and animals. In the present study, Lactobacillus delbrueckii subsp. bulgaricus KLDS1.0207 ( L. bulgaricus KLDS1.0207), which has a remarkable Pb binding capacity and Pb tolerance, was selected for further study. It was observed that the thermodynamic and kinetic model of L. bulgaricus KLDS1.0207 Pb binding respectively fit with the Langmuir-Freundlich model and the pseudo second-order kinetic model. Scanning electron microscopy and energy dispersive spectroscopy analysis disclosed that the cell surfaces were covered with Pb and that carbon and oxygen elements were chiefly involved in Pb binding. Combined with Fourier transform infrared spectroscopy analysis, it was revealed that the carboxyl, phosphoryl, hydroxyl, amino and amide groups were the main functional groups involved in the Pb adsorption. The protective effects of L. bulgaricus KLDS1.0207 against acute Pb toxicity in mice was evaluated by prevention and therapy groups, the results in vivo showed that L. bulgaricus KLDS1.0207 treatment could reduce mortality rates, effectively increase Pb levels in the feces, alleviate tissue Pb enrichment, improve the antioxidant index in the liver and kidney, and relieve renal pathological damage. Our findings show that L. bulgaricus KLDS1.0207 can be used as a potential probiotic against acute Pb toxicity.

Seed priming with KNO3 mediates biochemical processes to inhibit lead toxicity in maize (Zea mays L.).

PubMed

Nawaz, Fahim; Naeem, Muhammad; Akram, Asim; Ashraf, Muhammad Y; Ahmad, Khawaja S; Zulfiqar, Bilal; Sardar, Hasan; Shabbir, Rana N; Majeed, Sadia; Shehzad, Muhammad A; Anwar, Irfan

2017-11-01

Accumulation of lead (Pb) in agricultural soils has become a major factor for reduced crop yields and poses serious threats to humans consuming agricultural products. The present study investigated the effects of KNO 3 seed priming (0 and 0.5% KNO 3 ) on growth of maize (Zea mays L.) seedlings exposed to Pb toxicity (0, 1300 and 2550 mg kg -1 Pb). Pb exposure markedly reduced the growth of maize seedlings and resulted in higher Pb accumulation in roots than shoots. Pretreatment of seeds with KNO 3 significantly improved the germination percentage and increased physiological indices. A stimulating effect of KNO 3 seed priming was also observed on pigments (chlorophyll a, b, total chlorophyll and carotenoid contents) of Pb-stressed plants. Low translocation of Pb from roots to shoots caused an increased accumulation of total free amino acids and higher activities of catalase, peroxidase, superoxide dismutase and ascorbate peroxidase in roots as compared to shoot, which were further enhanced by exogenous KNO 3 supply to prevent Pb toxicity. Maize accumulates more Pb in roots than shoot at early growth stages. Priming of seeds with KNO 3 prevents Pb toxicity, which may be exploited to improve seedling establishment in crop species grown under Pb contaminated soils. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Evaluation of Mobility, Bioavailability and Toxicity of Pb and Cd in Contaminated Soil Using TCLP, BCR and Earthworms

PubMed Central

Kede, Maria Luiza F. M.; Correia, Fabio V.; Conceição, Paulo F.; Salles Junior, Sidney F.; Marques, Marcia; Moreira, Josino C.; Pérez, Daniel V.

2014-01-01

The objective of the present study was to investigate the reduction of mobility, availability and toxicity found in soil contaminated with lead (Pb) and cadmium (Cd) from Santo Amaro Municipality, Bahia, Brazil using two combined methods, commonly tested separately according to the literature: metal mobilization with phosphates and phytoextraction. The strategy applied was the treatment with two sources of phosphates (separately and mixed) followed by phytoremediation with vetiver grass (Vetiveria zizanioides (L.)). The treatments applied (in triplicates) were: T1—potassium dihydrogen phosphate (KH2PO4); T2—reactive natural phosphate fertilizer (NRP) and; T3—a mixture 1:1 of KH2PO4 and NRP. After this step, untreated and treated soils were planted with vetiver grass. The extraction procedures and assays applied to contaminated soil before and after the treatments included metal mobility test (TCLP); sequential extraction with BCR method; toxicity assays with Eisenia andrei. The soil-to-plant transfer factors (TF) for Pb and Cd were estimated in all cases. All treatments with phosphates followed by phytoremediation reduced the mobility and availability of Pb and Cd, being KH2PO4 (T1) plus phytoremediation the most effective one. Soil toxicity however, remained high after all treatments. PMID:25386955

Douglas fir (pseudotsuga menziesii) plantlets responses to as, PB, and sb-contaminated soils from former mines.

PubMed

Bonet, Amandine; Pascaud, Grégoire; Faugeron, Céline; Soubrand, Marilyne; Joussein, Emmanuel; Gloaguen, Vincent; Saladin, Gaëlle

2016-01-01

Phytoremediation of metalloids by conifers is not widely studied although they may be relevant for several contaminated sites, especially those located in cold areas and sometimes under dry climates. Here, seeds of Douglas fir were sown in greenhouse on three soils collected in two French former mines: a gold mine (soils L1 and L2) and a lead and silver mine (soil P). These soils are highly contaminated by Pb, As, and Sb at different concentrations. Plants were harvested after ten weeks. Growth parameters, primary metabolite content, and shoot and root ionomes were determined. Douglas firs grown on the soils L1 and P had a lower biomass than controls and a higher oxidation status whereas those grown on the soil L2 exhibited a more developed root system and only slight modifications of carbon and nitrogen nutrition. Based on trace element (TE) concentrations in shoots and roots and their translocation factor (TF), Douglas fir could be a relevant candidate for As phytoextraction (0.8 g. kg(-1) dry weight in shoots and a TF of 1.1) and may be used to phytostabilize Pb and Sb (8.8 g and 127 mg. kg(-1) in roots for Pb and Sb, respectively, and TF lower than 0.1).

Pollution characteristics and source identification of trace metals in riparian soils of Miyun Reservoir, China.

PubMed

Han, Lanfang; Gao, Bo; Lu, Jin; Zhou, Yang; Xu, Dongyu; Gao, Li; Sun, Ke

2017-10-01

The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline soils into Miyun Reservoir (MYR). Here, riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution. The potential ecological risk assessment revealed considerable contamination of recreational land, with Cd being the predominant contaminant. Chemical fractionations showed that Cu, arsenic (As), Pb and Cd had potential release risks. Additionally, the 206 Pb/ 207 Pb and 208 Pb/ 207 Pb values of soils were similar to those of coal combustion. By combining principal component analysis (PCA) with Pb isotopic results, coal combustion was identified as the major anthropogenic source of Zn, Cr, Cu, Cd and Pb. Moreover, isotope ratios of Pb fell in the scope of aerosols, indicating that atmospheric deposition may be the primary input pathway of anthropogenic Zn, Cr, Cu, Cd and Pb. Therefore, controlling coal combustion should be a priority to reduce effectively the introduction of additional Zn, Cu, Cd, and Pb to the area in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of genotoxic effects of lead in occupationally exposed workers.

PubMed

Chinde, Srinivas; Kumari, Monika; Devi, Kanapuram Rudrama; Murty, Upadhyayula Suryanarayana; Rahman, Mohammed Fazlur; Kumari, Srinivas Indu; Mahboob, Mohammed; Grover, Paramjit

2014-10-01

The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P < 0.01) increase in mean percent tail DNA, frequency of CA, and MN in PBL as well as in BEC as compared to controls. Pb in ambient air and B-Pb concentrations were found to be significantly higher (P < 0.01). The hematocrit, hemoglobin, and red blood cell values were significantly lowered in Pb-exposed workers in comparison to controls. SOD, GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.

Effects of nitrate on the treatment of lead contaminated groundwater by nanoscale zerovalent iron.

PubMed

Su, Yiming; Adeleye, Adeyemi S; Zhou, Xuefei; Dai, Chaomeng; Zhang, Weixian; Keller, Arturo A; Zhang, Yalei

2014-09-15

Nanoscale zerovalent iron (nZVI) is efficient for removing Pb(2+) and nitrate from water. However, the influence of nitrate, a common groundwater anion, on Pb(2+) removal by nZVI is not well understood. In this study, we showed that under excess Fe(0) conditions (molar ratio of Fe(0)/nitrate>4), Pb(2+) ions were immobilized more quickly (<5 min) than in nitrate-free systems (∼ 15 min) due to increasing pH. With nitrate in excess (molar ratio of Fe(0)/nitrate<4), nitrate stimulated the formation of crystal PbxFe3-xO4 (ferrite), which provided additional Pb(2+) removal. However, ∼ 7% of immobilized Pb(2+) ions were released into aqueous phase within 2h due to ferrite deformation. Oxidation-reduction potential (ORP) values below -600 mV correlated with excess Fe(0) conditions (complete Pb(2+) immobilization), while ORP values ≥-475 mV characterized excess nitrate conditions (ferrite process and Pb(2+) release occurrence). This study indicates that ORP monitoring is important for proper management of nZVI-based remediation in the subsurface to avoid lead remobilization in the presence of nitrate. Copyright © 2014 Elsevier B.V. All rights reserved.

Childhood lead poisoning from the smelter in Torreón, México.

PubMed

Soto-Jiménez, Martin F; Flegal, Arthur R

2011-05-01

Lead concentrations and isotopic compositions in blood samples of 34 children (ages 2-17 years) living within a 113 km(2) area of a silver-zinc-lead smelter plant in Torreón, México were compared to those of associated environmental samples (soil, aerosols, and outdoor and indoor dust) to identify the principal source(s) of environmental and human lead contamination in the area. Lead concentrations of soil and outdoor dust ranged 130-12,050 and 150-14,365 μg g(-1), respectively. Concentrations were greatest near the smelter, with the highest levels corresponding with the prevailing wind direction, and orders of magnitude above background concentrations of 7.3-33.3 μg g(-1). Atmospheric lead depositions in the city varied between 130 and 1350 μg m(-2) d(-1), again with highest rates <1 km from the smelter. Blood lead (PbB) concentrations (11.0±5.3 μg dl(-1)) levels in the children ranged 5.0-25.8 μg dl(-1), which is 3-14 times higher than the current average (1.9 μg dl(-1)) of children (ages 1-5 years) in the US. Lead isotopic ratios ((206)Pb/(207)Pb, (208)Pb/(207)Pb) of the urban dust and soil (1.200±0.009, 2.467±0.003), aerosols (1.200±0.002, 2.466±0.002), and PbB (1.199±0.001, 2.468±0.002) were indistinguishable from each other, as well as those of the lead ores processed at the smelter (1.199±0.007, 2.473±0.007). Consequently, an elevated PbB concentrations of the children in Torreón, as well as in their environment, are still dominated by industrial emissions from the smelter located within the city, in spite of new controls on atmospheric releases from the facility. Copyright © 2011 Elsevier Inc. All rights reserved.

Using the Mehlich-3 Soil Test as an Inexpensive Screening Tool to Estimate Total and Bioaccessible Lead in Urban Soils

EPA Science Inventory

In cities nationwide, urban agriculture has been put on hold because of the high costs of soil testing for historical contaminants such as lead (Pb). The Mehlich-3 soil test is commonly used to determine plant available nutrients, is inexpensive, and has the potential to estimate...

Variations of Soil Lead in Different Land Uses Along the Urbanization Gradient in the Beijing Metropolitan Area

PubMed Central

Mao, Qizheng; Huang, Ganlin; Ma, Keming; Sun, Zexiang

2014-01-01

Understanding the spatial pattern of soil lead (Pb) levels is essential to protecting human health. Most previous studies have examined soil Pb distributions by either urbanization gradient or land-use type. Few studies, however, have examined both factors together. It remains unclear whether the impacts of land use on soil Pb levels are consistent along the urbanization gradient. To fill this gap, we investigated variations in soil Pb level under different land-use types along the urbanization gradient in Beijing, China. We classified the degree of urbanization as the urban core, transitional zone, or suburban area and the land-use type as industrial area, roadside, residential area, institutional area, road greenbelt, park, or forest. Our results showed that the range of soil Pb levels in Beijing is <1 mg/kg–292 mg/kg, with a mean of 22 mg/kg. Along the urbanization gradient, the mean soil Pb level increased from the suburban area to the urban core. Land-use types have an impact on soil Pb levels, however, when the degree of urbanization is considered, the impact from land use on soil Pb level was only significant in the transitional zone. Parks and road greenbelts were found to have lower soil Pb, primarily due to soil restoration. Roadside and residential areas were found to have higher soil Pb because of traffic emissions, leaded paint, and previous industrial contamination. In the urban core and suburban area, the soil Pb level showed no significant differences among various land-use types. Given the results of soil Pb in various land-use types, we suggest that future studies consider the urbanization gradient in which different land-use samples are located. PMID:24646863

Variations of soil lead in different land uses along the urbanization gradient in the Beijing metropolitan area.

PubMed

Mao, Qizheng; Huang, Ganlin; Ma, Keming; Sun, Zexiang

2014-03-18

Understanding the spatial pattern of soil lead (Pb) levels is essential to protecting human health. Most previous studies have examined soil Pb distributions by either urbanization gradient or land-use type. Few studies, however, have examined both factors together. It remains unclear whether the impacts of land use on soil Pb levels are consistent along the urbanization gradient. To fill this gap, we investigated variations in soil Pb level under different land-use types along the urbanization gradient in Beijing, China. We classified the degree of urbanization as the urban core, transitional zone, or suburban area and the land-use type as industrial area, roadside, residential area, institutional area, road greenbelt, park, or forest. Our results showed that the range of soil Pb levels in Beijing is <1 mg/kg-292 mg/kg, with a mean of 22 mg/kg. Along the urbanization gradient, the mean soil Pb level increased from the suburban area to the urban core. Land-use types have an impact on soil Pb levels, however, when the degree of urbanization is considered, the impact from land use on soil Pb level was only significant in the transitional zone. Parks and road greenbelts were found to have lower soil Pb, primarily due to soil restoration. Roadside and residential areas were found to have higher soil Pb because of traffic emissions, leaded paint, and previous industrial contamination. In the urban core and suburban area, the soil Pb level showed no significant differences among various land-use types. Given the results of soil Pb in various land-use types, we suggest that future studies consider the urbanization gradient in which different land-use samples are located.

Effect of EDTA on Pb(II) Uptake and Translocation by Tumbleweed (Salsola Kali): Agar and Hydroponics Studies

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

de la Rosa, Guadalupe; Gardea-Torresdey, Jorge L.; Peralta-Videa, Jose R.

Environmental accumulation of Pb represents a worldwide health hazard. While conventional cleanup techniques are generally expensive and soil disturbing, phytoremediation represents an inexpensive friendly option for the removal of contaminants from soil and water. In this research, tumbleweed (Salsola kali) plants exposed for 15 days to Pb(NO3)2 at 80 and 125 ppm in hydroponics and agar media, demonstrated a high capacity to uptake lead. The results showed that the plants cultivated in agar accumulated 25563, 5534 and 2185 mg Pb kg-1 DW in roots, stems and leaves, respectively. Moreover, Pb concentrations found in hydroponically grown tumbleweed plants tissues were 30744,more » 1511 and 1421 mg kg-1 DW in roots, stems and leaves, respectively. It was observed that EDTA enhanced Pb translocation. No Pb phytotoxic effects were observed during the experimental time period. Cellular structural features were also observed using TEM.« less

The legacy of lead (Pb) in fluvial bed sediments of an urban drainage basin, Oahu, Hawaii.

PubMed

Hotton, Veronica K; Sutherland, Ross A

2016-03-01

The study of fluvial bed sediments is essential for deciphering the impact of anthropogenic activities on water quality and drainage basin integrity. In this study, a systematic sampling design was employed to characterize the spatial variation of lead (Pb) concentrations in bed sediment of urban streams in the Palolo drainage basin, southeastern Oahu, Hawaii. Potentially bioavailable Pb was assessed with a dilute 0.5 N HCl extraction of the <63 μm grain-size fraction from the upper bed sediment layer of 169 samples from Palolo, Pukele, and Waiomao streams. Contamination of bed sediments was associated with the direct transport of legacy Pb from the leaded gasoline era to stream channels via a dense network of storm drains linked to road surfaces throughout the basin. The Palolo Stream had the highest median Pb concentration (134 mg/kg), and the greatest road and storm drain densities, the greatest population, and the most vehicle numbers. Lower median Pb concentrations were associated with the less impacted Pukele Stream (24 mg/kg), and Waiomao Stream (7 mg/kg). The median Pb enrichment ratio values followed the sequence of Palolo (68) > Pukele (19) > Waiomao (8). Comparisons to sediment quality guidelines and potential toxicity estimates using a logistic regression model (LRM) indicated a significant potential risk of Palolo Stream bed sediments to bottom-dwelling organisms.

Enrichment and geochemical mobility of heavy metals in bottom sediment of the Hoedong reservoir, Korea and their source apportionment.

PubMed

Lee, Pyeong-Koo; Kang, Min-Ju; Yu, Soonyoung; Ko, Kyung-Seok; Ha, Kyoochul; Shin, Seong-Cheon; Park, Jung Han

2017-10-01

Physicochemical characteristics of bottom sediment in the Hoedong reservoir were studied to evaluate the effectiveness of the reservoir as traps for trace metals. Roadside soil, stream sediment and background soil were also studied for comparison. Sequential extractions were carried out, and lead isotopic compositions of each extraction were determined to apportion Pb sources. Besides, particle size distribution of roadside soil, and metal concentrations and Pb isotopes of each size group were determined to characterize metal contamination. In result, Zn and Cu were enriched in sediment through roadside soil. The data on metal partitioning implied that Zn posed potential hazards for water quality. Meanwhile, the noticeable reduction of the 206 Pb/ 207 Pb isotopic ratio in the acid-soluble fraction in the size group 200 μm - 2 mm of national roadside soil indicated that this size group was highly contaminated by automotive emission with precipitation of acid-soluble secondary minerals during evaporation. Based on the Pb isotopic ratios, the dry deposition of Asian dust (AD) and non-Asian dust (NAD) affected roadside soil, while the effects of AD and NAD on bottom sediment appeared to be low given the low metal concentrations in sediment. Metal concentrations and Pb isotopic compositions indicated that sediments were a mixture of background and roadside soil. Source apportionment calculations showed that the average proportion of traffic Pb in bottom and stream sediments was respectively 34 and 31% in non-residual fractions, and 26 and 28% in residual fraction. The residual fraction of sediments appeared to be as contaminated as the non-residual fractions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of soil dilution and amendments (mussel shell, cow bone, and biochar) on Pb availability and phytotoxicity in military shooting range soil.

PubMed

Ahmad, Mahtab; Soo Lee, Sang; Yang, Jae E; Ro, Hee-Myong; Han Lee, Young; Sik Ok, Yong

2012-05-01

Bioavailability and bioaccessibility determine the level of metal toxicity in the soils. Inorganic soil amendments may decrease metal bioavailability and enhance soil quality. This study used mussel shell, cow bone, and biochar to reduce lead (Pb) toxicity in the highly contaminated military shooting range soil in Korea. Water-soluble and 1-M ammonium nitrate extractions, and a modified physiologically based extraction test (PBET) were performed to determine Pb bioavailability and bioaccessibility in the soil, respectively. Active C in the soil was also measured to evaluate the effects of the amendments on biological soil quality. The Pb contaminated soil was diluted in serial with uncontaminated soil for the bioassays. Seed germination and root elongation tests using lettuce (Lactuca sativa) showed increases in germination percentage and root length in soil treated with the amendments. Biochar was most effective and increased seed germination by 360% and root length by 189% compared to the unamended soil. Up to 20% soil dilution resulted in more than 50% seed germination. Bioavailability and bioaccessibility of Pb in the soils were decreased by 92.5% and 48.5% with mussel shell, by 84.8% and 34.5% with cow bone, and by 75.8% and 12.5% with biochar, respectively, compared to the unamended soil. We found that the Pb availability in the military shooting range soil can be reduced effectively by the tested amendments or soil dilution alternately, thereby decreasing the risk of ecotoxicity. Furthermore, the increasing active C from the amendments revitalized the soil contaminated with Pb. Copyright © 2012 Elsevier Inc. All rights reserved.

Population specific fitness response of Drosophila subobscura to lead pollution.

PubMed

Kenig, Bojan; Stamenković-Radak, Marina; Andelković, Marko

2013-04-01

Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms responsible for the increased tolerance were genetically determined. Drosophila subobscura Collin (Diptera: Drosophilidae) populations were sampled from two localities with different history of heavy metal pollution, and reared for eight generations in the laboratory on a standard medium and on media with different concentrations of lead (Pb). To determine whether flies from different natural populations exposed to the Pb-contaminated media in the laboratory show population specific variability in fitness components over generations, experimental groups with different concentrations of lead were assayed in three generations (F2 , F5 , and F8 ) for fecundity, developmental time, and egg-to-adult viability. On the contaminated medium, fecundity was reduced in later generations and viability was increased, irrespective of the environmental origin of populations. For both populations, developmental time showed a tendency of slowing down on media with lead. Faster development was observed in later generations. Preadaptation to contamination, meaning higher fecundity, higher viability, and faster egg to adult development in all studied generations, was found in D. subobscura originating from the locality with a higher level of heavy metal pollution. © 2012 The Authors Insect Science © 2012 Institute of Zoology, Chinese Academy of Sciences.

Lead (Pb) contamination of self-supply groundwater systems in coastal Madagascar and predictions of blood lead levels in exposed children.

PubMed

Akers, D Brad; MacCarthy, Michael F; Cunningham, Jeffrey A; Annis, Jonathan; Mihelcic, James R

2015-03-03

Thousands of households in coastal Madagascar rely on locally manufactured pitcher-pump systems to provide water for drinking, cooking, and household use. These pumps typically include components made from lead (Pb). In this study, concentrations of Pb in water were monitored at 18 household pitcher pumps in the city of Tamatave over three sampling campaigns. Concentrations of Pb frequently exceeded the World Health Organization's provisional guideline for drinking water of 10 μg/L. Under first-draw conditions (i.e., after a pump had been inactive for 1 h), 67% of samples analyzed were in excess of 10 μg/L Pb, with a median concentration of 13 μg/L. However, flushing the pump systems before collecting water resulted in a statistically significant (p < 0.0001) decrease in Pb concentrations: 35% of samples collected after flushing exceeded 10 μg/L, with a median concentration of 9 μg/L. Based on measured Pb concentrations, a biokinetic model estimates that anywhere from 15% to 70% of children living in households with pitcher pumps may be at risk for elevated blood lead levels (>5 μg/dL). Measured Pb concentrations in water were not correlated at statistically significant levels with pump-system age, well depth, system manufacturer, or season of sample collection; only the contact time (i.e., flushed or first-draw condition) was observed to correlate significantly with Pb concentrations. In two of the 18 systems, Pb valve weights were replaced with iron, which decreased the observed Pb concentrations in the water by 57-89% in one pump and by 89-96% in the other. Both systems produced samples exclusively below 10 μg/L after substitution. Therefore, relatively straightforward operational changes on the part of the pump-system manufacturers and pump users might reduce Pb exposure, thereby helping to ensure the continued sustainability of pitcher pumps in Madagascar.

Assessment of waste oyster shells and coal mine drainage sludge for the stabilization of As-, Pb-, and Cu-contaminated soil.

PubMed

Moon, Deok Hyun; Cheong, Kyung Hoon; Koutsospyros, Agamemnon; Chang, Yoon-Young; Hyun, Seunghun; Ok, Yong Sik; Park, Jeong-Hun

2016-02-01

A novel treatment mix was designed for the simultaneous immobilization of As, Cu, and Pb in contaminated soils using natural (waste oyster shells (WOS)) and industrial (coal mine drainage sludge (CMDS)) waste materials. The treatments were conducted using the standard U.S. sieve size no. 20 (0.85 mm) calcined oyster shells (COS) and CMDS materials with a curing time of 1 and 28 days. The As immobilization treatments were evaluated using the 1-N HCl extraction fluid, whereas the Pb and Cu immobilization treatments were evaluated using the 0.1-N HCl extraction fluid based on the Korean leaching standards. The treatment results showed that the immobilization of As, Cu, and Pb was best achieved using a combination mix of 10 wt% COS and 10 wt% CMDS. This treatment mix was highly effective leading to superior leachability reductions for all three target contaminants (>93 % for As and >99 % for Cu and Pb) for a curing period of 28 days. The X-ray absorption near-edge structure (XANES) results showed that As was present in the form of As(V) in the control sample and that no changes in As speciation were observed following the COS-CMDS treatments. The scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) sample treated with 10 wt% COS and 10 wt% CMDS indicated that As immobilization may be associated with the formation of Ca-As and Fe-As precipitates while Pb and Cu immobilization was most probably linked to calcium silicate hydrates (CSHs) and calcium aluminum hydrates (CAHs).

Distribution and mobility of copper, zinc and lead in plant-sediment systems of Quanzhou Bay estuary, China.

PubMed

Li, Yu-Hong; Hu, Hong-You; Liu, Jing-Chun; Wu, Gui-Lan

2010-03-01

The distribution, mobility and potential risks of Cu, Zn, and Pb in four typical plant-sediment co-systems of the Quanzhou Bay estuary wetland in southeast China were investigated using a sequential extraction procedure. The results show that the sediments were moderately or heavily contaminated with Zn and Pb in all four plant communities, and the plant-sediment systems could act as a sink for the heavy metals. In all investigated sediments, only a small proportion of measured heavy metals were distributed in exchangeable fraction and carbonate fraction, while the reducible fraction contained the highest amount of Zn and Pb of the total readily bioavailable fractions, and the oxidizable fraction exhibited a higher retention capacity for Zn and Cu, but lower for Pb. Alternanthera philoxeroides had the best ability to accumulate heavy metals among the four species. Phragmites communis was quite tolerant to Zn and Pb and had a good capability to transfer Zn and Pb. Aegiceras corniculatum seems to be effective in resisting heavy metal pollution, and therefore cannot serve as an indicator of contamination. The urgent need for many local enterprises is to carry out high-tech cleaner production to reduce the emission of pollutants and achieve a resource-economical and environment-friendly development.

Heavy metal contamination characteristic of soil in WEEE (waste electrical and electronic equipment) dismantling community: a case study of Bangkok, Thailand.

PubMed

Damrongsiri, Seelawut; Vassanadumrongdee, Sujitra; Tanwattana, Puntita

2016-09-01

Sue Yai Utit is an old community located in Bangkok, Thailand which dismantles waste electrical and electronic equipment (WEEE). The surface soil samples at the dismantling site were contaminated with copper (Cu), lead (Pb), zinc (Zn), and nickel (Ni) higher than Dutch Standards, especially around the WEEE dumps. Residual fractions of Cu, Pb, Zn, and Ni in coarse soil particles were greater than in finer soil. However, those metals bonded to Fe-Mn oxides were considerably greater in fine soil particles. The distribution of Zn in the mobile fraction and a higher concentration in finer soil particles indicated its readily leachable character. The concentration of Cu, Pb, and Ni in both fine and coarse soil particles was mostly not significantly different. The fractionation of heavy metals at this dismantling site was comparable to the background. The contamination characteristics differed from pollution by other sources, which generally demonstrated the magnification of the non-residual fraction. A distribution pathway was proposed whereby contamination began by the deposition of WEEE scrap directly onto the soil surface as a source of heavy metal. This then accumulated, corroded, and was released via natural processes, becoming redistributed among the soil material. Therefore, the concentrations of both the residual and non-residual fractions of heavy metals in WEEE-contaminated soil increased.

Trace metal and metalloid contamination levels in soils and in two native plant species of a former industrial site: evaluation of the phytostabilization potential.

PubMed

Testiati, Eti; Parinet, Julien; Massiani, Catherine; Laffont-Schwob, Isabelle; Rabier, Jacques; Pfeifer, Hans-Rudolf; Lenoble, Véronique; Masotti, Véronique; Prudent, Pascale

2013-03-15

This study aimed at identifying the extent and type of contamination of a former lead smelting site in the area of Marseille, France, dating from the industrial revolution, and to evaluate environmental hazards and opportunities for phytoremediation, a promising sustainable technology. Amongst the native plants growing in this semiarid shrub ecosystem, two perennials Globularia alypum L. and Rosmarinus officinalis L. were selected. Twenty-one soil/plant couples were collected and seventeen additional soil samples were added to better characterize the soil pollution of the area. A multi-contamination by Pb, As, Sb, Zn, Cu was demonstrated, with huge variations within the contamination levels. The soils highest concentrations were encountered along the horizontal chimney and on the slag heaps area. However, both sites differed from each other. The former was characterized by the highest Pb, As and Sb concentrations that could reach 130, 7.0 and 9.0gkg(-1) respectively, the latter, by high Cu, Fe, Mn, S concentrations, even if it was also heavily contaminated by Pb and Zn. G. alypum and R. officinalis were shown to be metal-tolerant and to accumulate trace metals and As. Due to the low bioconcentration and translocation factors determined, both species may not be used for phytoextraction, but seem to be good candidates for phytostabilization. Copyright © 2013 Elsevier B.V. All rights reserved.

Spatial distribution and potential biological risk of some metals in relation to granulometric content in core sediments from Chilika Lake, India.

PubMed

Barik, Saroja K; Muduli, Pradipta R; Mohanty, Bita; Rath, Prasanta; Samanta, Srikanta

2018-01-01

The article presents first systematic report on the concentration of selected major elements [iron (Fe) and manganese (Mn)] and minor elements [zinc (Zn), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), and cobalt (Co)] from the core sediment of Chilika Lake, India. The analyzed samples revealed higher content of Pb than the background levels in the entire study area. The extent of contamination from minor and major elements is expressed by assessing (i) the metal enrichments in the sediment through the calculations of anthropogenic factor (AF), pollution load index (PLI), Enrichment factor (EF), and geoaccumulation index (Igeo) and (ii) potential biological risks by the use of sediment quality guidelines like effect range median (ERM) and effect range low (ERL) benchmarks. The estimated indices indicated that sediment is enriched with Pb, Ni, Cr, Cu and Co. The enrichment of these elements seems to be due to the fine granulometric characteristics of the sediment with Fe and Mn oxyhydroxides being the main metal carriers and fishing boats using low grade paints, fuel, and fishing technology using lead beads fixed to fishing nets. Trace element input to the Chilika lake needs to be monitored with due emphasis on Cr and Pb contaminations since the ERM and ERL benchmarks indicated potential biological risk with these metals.

Assessment of the Spatial Distribution of Metal(Oid)s in Soils Around an Abandoned Pb-Smelter Plant

NASA Astrophysics Data System (ADS)

dos Santos, Nielson Machado; do Nascimento, Clístenes Williams Araújo; Matschullat, Jörg; de Olinda, Ricardo Alves

2017-03-01

Todos os Santos (All Saints) Bay area, NE-Brazil, is known for one of the most important cases of urban lead (Pb) contamination in the world. The main objective of this work was to assess and interpret the spatial distribution of As, Cd, Hg, Pb, and Zn in "background" soils of this environmentally impacted bay area, using a combination of geostatistical and multivariate analytical methods to distinguish between natural and anthropogenic sources of those metal(oid)s in soils. We collected 114 topsoil samples (0.0-0.2 m depth) from 38 sites. The median values for trace metal concentrations in soils (mg kg-1) followed the order Pb (33.9) > Zn (8.8) > As (1.2) > Cd (0.2) > Hg (0.07), clearly reflecting a Pb-contamination issue. Principal component analysis linked Cd, Pb, and Zn to the same factor (F1), chiefly corroborating their anthropogenic origin; yet, both Pb and Zn are also influenced by natural lithogenic sources. Arsenic and Hg concentrations (F2) are likely related to the natural component alone; their parent material (igneous-metamorphic rocks) seemingly confirm this hypothesis. The heterogeneity of sources and the complexity of the spatial distribution of metals in large areas such as the Todos os Santos Bay warrant, the importance of multivariate and geostatistical analyses in the interpretation of environmental data.

Assessment of Cr, Ni and Pb Pollution in Rural Agricultural Soils of Tonalite-Trondjhemite Series in Central India.

PubMed

Shukla, Kriti; Kumar, Bijendra; Agrawal, Rahul; Priyanka, Kumari; Venkatesh, Madavi; Anshumali

2017-06-01

Chromium (Cr), nickel (Ni) and lead (Pb) contamination was investigated in wheat cultivated rain-fed and irrigated rural agricultural soils (n = 31) of Tonalite-Trondjhemite Series in Central India. The soil sampling was carried out by using stratified random sampling method. The mean concentrations of Cr, Ni and Pb were 54.8, 38.1 and 68.9 mg/kg, respectively. The average values of enrichment factor (EF), geoaccumulation index (I geo ) and contamination factor (CF) followed the order as: Pb > Ni > Cr. Distribution patterns of soil parent material and weathering processes govern mineral enrichments, irrespective of rainfed or irrigated agricultural practices. Principal component analysis (PCA) showed strong loading of Cr and Ni (PC1) and Pb and clay (PC3). The strong loading on Cr and Ni indicates soils are originating from basic and volcanic rocks in the study area. The strong loading of Pb and clay indicates Pb is strongly adsorbed on clay minerals and Fe-oxides. The cancer risk (CR) index showed negligible carcinogenic risk to the residing population. However, hazard index (HI) values for children exceed the safe limit (HI > 1) for Cr and Pb. Spatial distribution of pollution load index suggest highest pollution in the northeastern part of the district. The study revealed that geogenically enriched soils of the area are suitable for agricultural activities under present conditions.

Interaction effects and mechanism of Pb pollution and soil microorganism in the presence of earthworm.

PubMed

Liu, Gao; Ling, Siyuan; Zhan, Xiuping; Lin, Zhifen; Zhang, Wei; Lin, Kuangfei

2017-04-01

Heavy metals usually cause great damage to soil ecosystem. Lead (Pb) was chosen as a research object in the present study. Here repeated exposure of Pb was designed for the soil artificially contaminated. A laboratory study was conducted to determine the changes in the Pb availability and biological activity in the presence of earthworm, and the risk assessment code (RAC) was applied to evaluate the remediated soil. Results demonstrated that Pb gradually transformed to more stable fractions (OMB- and FeMnOX-Pb) under microbial action, indicating the risk level of Pb was declined. On the other hand, Pb also caused the inhibition of soil respiration and microbial biomass, and the higher the concentration of Pb, the stronger the inhibition; While in the presence of earthworm, it could absorb Pb and facilitate microbial activity, reflected the decrease of Pb content and the increase of respiration intensity in soil, as well as microbial biomass. Additionally, a good dose-response relationship between EXCH-Pb content and respiration intensity might provide a basis for ecological risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trace metal inventories and lead isotopic composition chronicle a forest fire's remobilization of industrial contaminants deposited in the angeles national forest.

PubMed

Odigie, Kingsley O; Flegal, A Russell

2014-01-01

The amounts of labile trace metals: [Co] (3 to 11 µg g-1), [Cu] (15 to 69 µg g-1), [Ni] (6 to 15 µg g-1), [Pb] (7 to 42 µg g-1), and [Zn] (65 to 500 µg g-1) in ash collected from the 2012 Williams Fire in Los Angeles, California attest to the role of fires in remobilizing industrial metals deposited in forests. These remobilized trace metals may be dispersed by winds, increasing human exposures, and they may be deposited in water bodies, increasing exposures in aquatic ecosystems. Correlations between the concentrations of these trace metals, normalized to Fe, in ash from the fire suggest that Co, Cu, and Ni in most of those samples were predominantly from natural sources, whereas Pb and Zn were enriched in some ash samples. The predominantly anthropogenic source of excess Pb in the ash was further demonstrated by its isotopic ratios (208Pb/207Pb: 206Pb/207Pb) that fell between those of natural Pb and leaded gasoline sold in California during the previous century. These analyses substantiate current human and environmental health concerns with the pyrogenic remobilization of toxic metals, which are compounded by projections of increases in the intensity and frequency of wildfires associated with climate change.

New isotopic evidence of lead contamination in wheat grain from atmospheric fallout.

PubMed

Yang, Jun; Chen, Tongbin; Lei, Mei; Zhou, Xiaoyong; Huang, Qifei; Ma, Chuang; Gu, Runyao; Guo, Guanghui

2015-10-01

Crops could accumulate trace metals by soil-root transfer and foliar uptake from atmospheric fallout, and an accurate assessment of pollution sources is a prerequisite for preventing heavy metal pollution in agricultural products. In this study, we examined Pb isotope rates to trace the sources of Pb in wheat grain grown in suburbs. Results showed that, even in zones with scarcely any air pollution spots, atmospheric fallout was still a considerable source of Pb accumulation in wheat. The concentration of Pb in wheat grain has poor correlation with that in farm soil. The Pb concentration in wheat grains with dust in bran coat was significantly higher than that in wheat grains, which indicates that Pb may accumulate by foliar uptake. The Pb isotope rate has obvious differences between the soil and atmospheric fallout, and scatter ratio is significantly closer between the wheat grain and atmospheric fallout. Atmospheric fallout is a more significant source of Pb concentration in wheat grains than in soil. As far as we know, this is the first study on the main sources of lead in grain crop (wheat) samples with isotope. This study aims to improve our understanding of the translocation of foliar-absorbed metals to nonexposed parts of plants.

Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil.

PubMed

Gattai, Graziella S; Pereira, Sônia V; Costa, Cynthia M C; Lima, Cláudia E P; Maia, Leonor C

2011-07-01

The goals of this study were to evaluate the microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants (Caesalpinia ferrea, Mimosa tenuiflora and Erythrina velutina) in lead contaminated soil from the semi-arid region of northeastern of Brazil (Belo Jardim, Pernambuco). Dilutions were prepared by adding lead contaminated soil (270 mg Kg(-1)) to uncontaminated soil (37 mg Pb Kg soil(-1)) in the proportions of 7.5%, 15%, and 30% (v:v). The increase of lead contamination in the soil negatively influenced the amount of carbon in the microbial biomass of the samples from both the dry and rainy seasons and the metabolic quotient only differed between the collection seasons in the 30% contaminated soil. The average value of the acid phosphatase activity in the dry season was 2.3 times higher than observed during the rainy season. There was no significant difference in the number of glomerospores observed between soils and periods studied. The most probable number of infective propagules was reduced for both seasons due to the excess lead in soil. The mycorrhizal colonization rate was reduced for the three plant species assayed. The inoculation with arbuscular mycorrhizal fungi benefited the growth of Erythrina velutina in lead contaminated soil.

Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil

PubMed Central

Gattai, Graziella S.; Pereira, Sônia V.; Costa, Cynthia M. C.; Lima, Cláudia E. P.; Maia, Leonor C.

2011-01-01

The goals of this study were to evaluate the microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants (Caesalpinia ferrea, Mimosa tenuiflora and Erythrina velutina) in lead contaminated soil from the semi-arid region of northeastern of Brazil (Belo Jardim, Pernambuco). Dilutions were prepared by adding lead contaminated soil (270 mg Kg-1) to uncontaminated soil (37 mg Pb Kg soil-1) in the proportions of 7.5%, 15%, and 30% (v:v). The increase of lead contamination in the soil negatively influenced the amount of carbon in the microbial biomass of the samples from both the dry and rainy seasons and the metabolic quotient only differed between the collection seasons in the 30% contaminated soil. The average value of the acid phosphatase activity in the dry season was 2.3 times higher than observed during the rainy season. There was no significant difference in the number of glomerospores observed between soils and periods studied. The most probable number of infective propagules was reduced for both seasons due to the excess lead in soil. The mycorrhizal colonization rate was reduced for the three plant species assayed. The inoculation with arbuscular mycorrhizal fungi benefited the growth of Erythrina velutina in lead contaminated soil. PMID:24031701

Soil solution interactions may limit Pb remediation using P amendments in an urban soil

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

Obrycki, John F.; Scheckel, Kirk G.; Basta, Nicholas T.

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg -1 was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organicmore » acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm -1, potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. More research is needed to characterize soil solutions in Pb contaminated urban soils to identify where P treatments might be effective and when competing cations, such as Ca, Fe, and Zn may limit low rate P applications for treating Pb soils.« less

Assessing the State of Contamination in a Historic Mining Town Using Sediment Chemistry.

PubMed

Gutiérrez, Mélida; Wu, Shuo-Sheng; Rodriguez, Jameelah R; Jones, Ashton D; Lockwood, Benjamin E

2016-05-01

The United States town of Aurora, Missouri, USA, stockpiled lead (Pb) and zinc (Zn) mining wastes from the early to mid-1900s in the form of chat piles. Clean-up actions were undertaken at intervals in subsequent years including land leveling and removal of chat. This study assessed the current state of contamination by identifying areas where metals are present at toxic levels. For this purpose, stream sediment samples (N = 100) were collected over a 9 × 12 km area in and around Aurora. Their content of cadmium (Cd), Pb, and Zn were measured, and concentration maps were generated using ArcGIS to categorize affected areas. Metal concentrations varied over a wide range of values with the overall highest values observed in the north-northeast part of Aurora where abundant chat piles had been present. Comparison between observed concentrations and sediment-quality guidelines put the contaminated areas mentioned are above-toxic levels for Cd, Pb and Zn. In contrast, levels in rural areas and the southern part of Aurora were at background levels, thus posing no threat to aquatic habitats. The fact that contamination is constrained to a relatively small area can be advantageously used to implement further remediation and, by doing so, to help protect the underlying karst aquifer.

Contributions of Paint and Soil to Pb in Household Dust Wipes: An XAS Study

NASA Astrophysics Data System (ADS)

Pingitore, N. E.; Clague, J. W.; Amaya, M. A.

2010-12-01

Speciation of Pb by X-ray absorption spectroscopy (XAS) indicated that Pb compounds associated with lead-based paint accounted for perhaps half of the Pb in 24 household dust wipes collected in El Paso, Texas. Soil-derived, sorbed Pb, likely Pb-humate, was also a major Pb species in many of the dust wipes. Household dust wipes are a standard technique for evaluating health risks of Pb to children, particularly toddlers, in public and private housing. The level of Pb in the wipes does not, however, indicate whether the source of the Pb is the house itself (peeling or powdering interior or exterior paint) or external, from contaminated soil or airborne particulate matter brought into the house by wind or foot traction. Understanding the origin of Pb in household dust is important in remediation: cover the old paint or remove the yard soil. XAS speciation can assist in understanding the source of Pb in household dust. The presence of significant Pb-humate requires a soil source, and suggests the need for soil remediation. Such species of Pb as hydrocerussite, lead sulfate, lead silicate, and lead chromate can be presumed to be components of lead-based paint. These may represent interior and/or exterior paint and thus do not uniquely identify the locus of the Pb source(s). Pb L-III edge XAFS data were collected on beam lines 7-3, 10-2, and 11-2 at SSRL at typical conditions of 3 GeV field and 80-200 mA current, using Si(220) water- or liquid-nitrogen-cooled monochromator crystals. Data were collected at ambient temperature in fluorescence mode using a 13- or 30-element Ge detector with a Se 3 or 6 filter and Soller slits to reduce scattered radiation. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-01A1 from the National Institute of Environmental Health Sciences (NIEHS), NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. Portions of this research were carried out at the Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.

Environmental conditions in the Rudnaya River watershed--a compilation of Soviet and post-Soviet era sampling around a lead smelter in the Russian Far East.

PubMed

Kachur, Anatoly N; Arzhanova, Valentina S; Yelpatyevsky, Pavel V; von Braun, Margrit C; von Lindern, Ian H

2003-02-15

The Rudnaya River valley in the Russian Far East contains a rich reserve of lead, zinc and boron and has been mined for nearly 100 years. Environmental contamination related to the area's mines and lead smelter was studied for over 30 years during the Soviet era, by members of the Pacific Geographic Institute (PGI). Due to government restrictions, much of the sampling focused on contamination of the river, the air, forests, vegetation, agricultural products and soil. Source-specific samples, such as stack emissions from the smelter, and blood lead levels from the residents and smelter workers could not be obtained or were classified as State secrets. However, the data do describe the extent and severity of the environmental contamination and related public health concerns. Water discharged from the smelter averages 2900 m(3)/day (containing 100 kg of lead (Pb) and 20 kg of arsenic (As)) and leachate from area mine dumps and other industrial processes contaminates the Rudnaya River. Annual air emissions include 85 tonnes of particulates (containing 50 tonnes of Pb and 0.5 tonnes of As) and 250000 m(3) of gases high in sulfur dioxide (SO(2)), carbon monoxide (CO) and carbon dioxide (CO(2)). Vegetative stress is severe and much of this area is denuded. Pb and other metals in agricultural products suggest local produce may be dangerous for human consumption, although it is a major food source for the community. Public and occupational health indicators of basophilic stippling, respiratory disease and hair lead levels further suggest the severity of the problem. Although, descriptions of complete methodologies and procedures are often lacking, these data describe how sampling was conducted during the Soviet era and document a site with severe heavy metals contamination, especially lead, and the likelihood of related public health problems. They are relevant today as investigators employ state-of-the-art-sampling techniques and explore cleanup options under a new governmental system and challenging economic times. In the post-Soviet era, a Russian/US team sampled area soils and dusts and confirmed the severity of the environmental problems using commonly employed sampling and analysis techniques. Lead concentrations in residential gardens (476-4310 mg/kg, Gx=1626 mg/kg) and in roadside soils (2020-22900 mg/kg, Gx=4420 mg/kg) exceed USEPA guidance for remediation. Preliminary biokinetic estimates of mean blood levels (average 13-27 microg/dl) suggest pre-school children are at significant risk of lead poisoning from soil/dust ingestion. Today, the PGI, in cooperation with the industrial owners and the local health and environmental authorities, is attempting to establish long-term monitoring and pollution abatement within the constraints of their difficult economic situation.

Functional Expression of a Bacterial Heavy Metal Transporter in Arabidopsis Enhances Resistance to and Decreases Uptake of Heavy Metals1[w

PubMed Central

Lee, Joohyun; Bae, Hyunju; Jeong, Jeeyon; Lee, Jae-Yun; Yang, Young-Yell; Hwang, Inhwan; Martinoia, Enrico; Lee, Youngsook

2003-01-01

Large parts of agricultural soil are contaminated with lead (Pb) and cadmium (Cd). Although most environments are not heavily contaminated, the low levels observed nonetheless pose a high risk of heavy metal accumulation in the food chain. Therefore, approaches to develop plants with reduced heavy metal uptake are important. Recently, many transgenic plants with increased heavy metal resistance and uptake of heavy metals were developed for the purpose of phytoremediation. However, to reduce heavy metal in the food chain, plants that transfer less heavy metals to the shoot are required. We tested whether an Escherichia coli gene, ZntA, which encodes a Pb(II)/Cd(II)/Zn(II) pump, could be useful for developing plants with reduced heavy metal content. Yeast cells transformed with this gene had improved resistance to Pb(II) and Cd(II). In Arabidopsis plants transformed with ZntA, ZntA was localized at the plasma membrane and improved the resistance of the plants to Pb(II) and Cd(II). The shoots of the transgenic plants had decreased Pb and Cd content. Moreover, the transgenic protoplasts showed lower accumulation of Cd and faster release of preloaded Cd than wild-type protoplasts. These results show that a bacterial transporter gene, ZntA, can be functionally expressed in plant cells, and that that it may be useful for the development of crop plants that are safe from heavy metal contamination. PMID:14512517

Flow cytometric analysis of red-eared slider turtles (Trachemys scripta) from Tar Creek Superfund Site.

PubMed

Hays, Kimberly A; McBee, Karen

2007-05-01

Tar Creek Superfund Site (TCSFS) was heavily mined from the 1890s to 1970 and currently is contaminated with lead, zinc, and cadmium. Flow cytometry (FCM) was used to measure variation in nuclear DNA content of red blood cells collected from Trachemys scripta living within TCSFS and reference sites, Lake Carl Blackwell (LCB) and Sequoyah National Wildlife Refuge (SNWR). We also used atomic absorption spectrometry to measure Pb in blood and carapace and Cd in blood samples of turtles from TCSFS and SNWR. Mean coefficients of variation around the G(1) peak ranged from 5.33 to 5.48 and showed no significant difference between contaminated and reference populations; however, there was a significantly higher frequency of aneuploidy at TCSFS when compared with both reference populations. Blood Pb levels were not significantly different between TCSFS and SNWR populations. Pb levels in carapace samples did not differ significantly between sites; however, Pb levels were higher in carapace than blood for both populations. Blood Cd was significantly higher in animals at TCSFS than SNWR.

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.

Tracing geogenic and anthropogenic sources in urban dusts: Insights from lead isotopes

NASA Astrophysics Data System (ADS)

Del Rio-Salas, R.; Ruiz, J.; De la O-Villanueva, M.; Valencia-Moreno, M.; Moreno-Rodríguez, V.; Gómez-Alvarez, A.; Grijalva, T.; Mendivil, H.; Paz-Moreno, F.; Meza-Figueroa, D.

2012-12-01

Tracing the source of metals in the environment is critical to understanding their pollution level and fate. Geologic materials are an important source of airborne particulate matter, but the contribution of contaminated soil to concentrations of Pb in airborne dust is not yet widely documented. To examine the potential significance of this mechanism, surface soil samples were collected, as well as wind-transported dust trapped at 1 and 2 m height at seven different locations including residential, industrial, high-traffic and rural sites. Samples of dust deposited on roofs from 24 schools were also obtained and analyzed for Pb isotope ratios. Spatial distribution of Pb of airborne and sedimented dust suggests a process dominated by re-suspension/sedimentation, which was controlled by erosion, traffic and topography of the urban area. Anthropogenic lead input in the city grades outward the urban zone toward geogenic values. Our results shows that Pb-isotopic signatures of leaded gasoline are imprinted in dust sedimented on roofs. Considering that leaded-gasoline has not been in use in Mexico since two decades ago, this signature shows not only a Pb-legacy in soil, but also a re-suspension process affecting air column below 3 m in height. The combination of the 207Pb/206Pb data of the surrounding rocks and urban dust, reveal three well-defined zones with remarkable anthropogenic influence, which correspond to the oldest urban sectors. This work highlights the importance of spatial characterization of metals in particles suspended below a height of 3 m of the airborne column, a fact that should be considered to identify exposure paths to humans and the potential risks. Lead isotope signatures allowed the identification of geogenic and anthropogenic emission sources for dust, a matter that deserves consideration in the efforts to control airborne metal emissions.

Metal enrichment and lead isotope analysis for source apportionment in the urban dust and rural surface soil.

PubMed

Yu, Yang; Li, Yingxia; Li, Ben; Shen, Zhenyao; Stenstrom, Michael K

2016-09-01

To understand the metal accumulation in the environment and identify its sources, 29 different metal contents and lead (Pb) isotope ratios were determined for 40 urban dust samples, 36 surface soil samples, and one river sediment sample collected in the municipality of Beijing, China. Results showed that cadmium, copper (Cu), mercury, Pb, antimony (Sb), and zinc demonstrated to be the typical urban contaminants and mostly influenced by the adjacent human activities with higher content to background ratios and SD values. Among the 29 metal elements investigated, Cu and Sb were found to be the most distinct elements that were highly affected by the developing level and congestion status of the cities with much higher contents in dust in more developed and congested cities. There was a relatively wider range of Pb isotope ratios of country surface soil than those of urban dust. The results of source identification based on Pb isotope ratios showed that coal combustion was the first largest Pb source and vehicle exhaust was the second largest source. The sum of them accounted for 74.6% mass proportion of overall Pb pollution on average. The surface soil sample collected at an iron mine had the highest (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios indicating ore had much higher ratios than other sources. The fine particle subsamples had higher (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios than the coarse particle subsamples indicating more anthropogenic sources of coal combustion and vehicle exhaust for fine particles and more background influence for coarse particles. These results help with pinpointing the major Pb sources and applying suitable measures for the target sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Citric acid-assisted phytoextraction of lead: a field experiment.

PubMed

Freitas, Eriberto Vagner; Nascimento, Clístenes Williams; Souza, Adailson; Silva, Fernando Bruno

2013-06-01

Soil contamination with heavy metals has become a serious environmental problem that requires affordable strategies of remediation. This study was carried out to assess the performance of maize and vetiver in the phytoextraction of Pb from a soil contaminated by battery recycling activities. The species were planted with different spacings between rows (0.80, 0.65 and 0.50m). Citric acid (40mmolkg(-1)) was applied on each experimental plot on the 61st d of cultivation in order to solubilize the Pb and assist the phytoextraction. The results showed that the chelating agent promoted a 14-fold increase in the Pb concentration in maize shoots as compared to the control, which accumulated only 111mgkg(-1) of the metal. The citric acid induced a Pb concentration in vetiver shoots that was 7.2-6.7-fold higher than the control at both the 0.65 and 0.50m plant spacing, respectively. The use of citric acid increased substantially the uptake and translocation of Pb to the shoots, regardless of plant spacing. Citric acid was efficient in solubilizing Pb from the soil and inducing its uptake by both species. Environmentally-friendly and cost effective, commercial citric acid is recommended for assisting Pb-phytoextraction in the studied area. Due to the low natural solubility of Pb and a time frame needed of longer than 150yr to accomplish the clean-up, phytoextraction with no chelate assistance is not recommended for the area. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of different soil remediation methods on inhibition of lead absorption and growth and quality of Dianthus superbus L.

PubMed

Yang, Xiaoyu; Ma, Siyue; Li, Jianheng

2017-12-01

Heavy metal pollution in soil poses a serious threat to the growth of plants used in traditional Chinese medicine. Therefore, a pot experiment was conducted to study the effects of various soil remediation methods on the performance of Herba Dianthi (Dianthus superbus L.) grown on Pb-contaminated soil. The results show that inoculation of Herba Dianthi with arbuscular mycorrhizal fungi (AMF) led to a significant reduction in Pb uptake (P< 0.05), and increased root development and root-to-shoot ratio compared to untreated control plants, along with the highest content of active components. When planting with Trifolium repens, the reduction effect of Pb absorption was insignificant. Herba Dianthi showed improved growth and active ingredients, and the lowest Pb content, with AMF inoculation. The addition of EDTA decreased the growth of Herba Dianthi, but promoted the absorption of Pb. The inhibition of tumor cells was highest in E2. In conclusion, inoculation with AMF can ensure that plant lead content meets testing standards, helping to improve the quality of medicinal herbs.

Health risk assessment from contaminated foodstuffs: a field study in chromite mining-affected areas northern Pakistan.

PubMed

Nawab, Javed; Li, Gang; Khan, Sardar; Sher, Hassan; Aamir, Muhammad; Shamshad, Isha; Khan, Anwarzeb; Khan, Muhammad Amjad

2016-06-01

This study aimed to investigate the potential health risk associated with toxic metals in contaminated foodstuffs (fruits, vegetables, and cereals) collected from various agriculture fields present in chromite mining-affected areas of mafic and ultramafic terrains (northern Pakistan). The concentrations of Cr, Ni, Zn, Cd, and Pb were quantified in both soil and food samples. The soil samples were highly contaminated with Cr (320 mg/kg), Ni (108 mg/kg), and Cd (2.55 mg/kg), which exceeded their respective safe limits set by FAO/WHO. Heavy metal concentrations in soil were found in the order of Cr>Ni>Pb>Zn>Cd and showed significantly (p < 0.001) higher concentrations as compared to reference soil. The integrated pollution load index (PLI) value was observed greater than three indicating high level of contamination in the study area. The concentrations of Cr (1.80-6.99 mg/kg) and Cd (0.21-0.90 mg/kg) in foodstuffs exceeded their safe limits, while Zn, Pb, and Ni concentrations were observed within their safe limits. In all foodstuffs, the selected heavy metal concentrations were accumulated significantly (p < 0.001) higher as compared to the reference, while some heavy metals were observed higher but not significant like Zn in pear, persimmon, white mulberry, and date-plum; Cd in pear, fig and white mulberry; and Pb in walnut, fig, and pumpkin. The health risk assessment revealed no potential risk for both adults and children for the majority of heavy metals, except Cd, which showed health risk index (HRI) >1 for children and can pose potential health threats for local inhabitants. Graphical Abstract Heavy metals released from chromite mining lead to soil and foodstuff contamination and human health risk.

Heavy metal accumulation during the last 30 years in the Karnaphuli River estuary, Chittagong, Bangladesh.

PubMed

Wang, Ai-Jun; Kawser, Ahmed; Xu, Yong-Hang; Ye, Xiang; Rani, Seema; Chen, Ke-Liang

2016-01-01

Heavy metal contamination of aquatic environment has attracted global attention owing to its abundance, persistence, and environmental toxicity, especially in developing countries like Bangladesh. Five heavy metals, namely chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) were investigated in surface and core sediments of the Karnaphuli River (KR) estuary in Chittagong, Bangladesh, in order to reveal the heavy metal contamination history in estuarine sediments and its response to catastrophic events and human activities. The surface sediment was predominantly composed of silt and sand, and the surface sediment was contaminated with Cr and Pb. Based on the 210 Pb chronology, the sedimentation rate in the inter-tidal zone of KR estuary was 1.02 cm/a before 2007, and 1.14 cm/a after 2008. The core sediment collected from 8 to 20 cm below the surface mainly originated from terrestrial materials induced by catastrophic events such as cyclone, heavy rainfall and landslides in 2007 and 2008. The values of contamination factor ( CF ) showed that the sediment became moderately contaminated with Cr and Pb in the last 30 years. The variation and accumulation of heavy metals in core sediment before 2000 was mainly related to natural variations in sediment sources; however, in subsequent years, the anthropogenic inputs of heavy metals have increased due to rapid physical growth of urban and industrial areas in the Chittagong city. In general, the accumulation pattern of heavy metals after normalization to Aluminum in sediments of KR estuary indicated an accelerated rate of urbanization and industrialization in the last 30 years, and also suggested the influence of natural catastrophic event on estuarine environment.

Effects of vitamin E on lead-induced impairments in hippocampal synaptic plasticity.

PubMed

Salehi, Iraj; Karamian, Ruhollah; Komaki, Alireza; Tahmasebi, Lida; Taheri, Masoumeh; Nazari, Masoumeh; Shahidi, Siamak; Sarihi, Abdolrahman

2015-12-10

Lead (Pb) exposure during development is associated with impaired cognitive function and long-term potentiation (LTP). Vitamin E (VE) is an antioxidant that could have protective effects against Pb intoxication. In this study, we examined the protective effects of vitamin E against Pb-induced LTP impairments. Forty-six adult male Wistar rats were randomly divided into 6 treatment groups: (1) control; (2) Pb exposure; (3) VE; (4) Pb +VE; (5) Pb exposure followed by VE 2 months after exposure; (6) VE followed by Pb exposure 1 month after treatment. Rats were exposed to Pb through daily consumption of Pb-contaminated distilled water; VE was administered by daily gavage for 3 months. After this period, the population spike (PS) amplitudes and the slopes of excitatory postsynaptic potentials (EPSPs) were measured in the dentate gyrus (DG) area of the hippocampus in adult rats in response to electrical stimulation applied to the perforant pathway in vivo. Blood samples were also collected to evaluate malondialdehyde (MDA) levels, total antioxidant capacity (TAC), and total oxidant status (TOS). Biochemical analyses demonstrated significant increases in plasma MDA and TOS levels in the Pb-exposed group compared to the control group. VE-protected groups revealed significant increases in TAC levels. Our results demonstrate that Pb decreased EPSP slopes and PS amplitudes compared to the control group, whereas VE increased these parameters compared to the control group. Co-administration of VE with Pb exposure inhibited Pb-induced effects. These findings suggest that VE via its antioxidant activity reverses Pb-induced impairments of synaptic plasticity in the DG. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution and transport of sediment-bound metal contaminants in the rio grande de tarcoles, costa rica (Central America)

USGS Publications Warehouse

Fuller, C.C.; Davis, J.A.; Cain, D.J.; Lamothe, P.J.; Fries Fernandez, T.L.G.; Vargas, J.A.; Murillo, M.M.

1990-01-01

A reconnaissance survey of the extent of metal contamination in the Rio Grande de Tarcoles river system of Costa Rica indicated high levels of chromium (Cr) in the fine-grain bed sediments (83 times Cr background or 3000->5000 ??g/g). In the main channel of the river downstream of the San Jose urban area, Cr contamination in sediments was 4-6 times background and remained relatively constant over 50 km to the mouth of the river. Sediment from a mangrove swamp at the river mouth had Cr levels 2-3 times above background. Similar patterns of dilution were observed for lead (Pb) and zinc (Zn) sediment contamination, although the contamination levels were lower. The high affinity of Cr towards particulate phases, probably as Cr(III), allows the use of Cr contamination levels for delineating regions of deposition of fine-grained sediments and dilution of particle associated contaminants during transport and deposition.A reconnaissance survey of the extent of metal contamination in the Rio Grande de Tarcoles river system of Costa Rica indicated high levels of chromium (Cr) in the fine-grain bed sediments (83 times Cr background or 3000->5000 ??g/g). In the main channel of the river downstream of the San Jose urban area, Cr contamination in sediments was 4-6 times background and remained relatively constant over 50 km to the mouth of the river. Sediments from a mangrove swamp at the river mouth had Cr levels 2-3 times above background. Similar patterns of dilution were observed for lead (Pb) and zinc (Zn) sediment contamination, although the contamination levels were lower. The high affinity of Cr towards particulate phases, probably as Cr(III), allows the use of Cr contamination levels for delineating regions of deposition of fine-grained sediments and dilution of particle associated contaminants during transport and deposition.

Effects of low molecular weight organic acids on the immobilization of aqueous Pb(II) using phosphate rock and different crystallized hydroxyapatite.

PubMed

Wei, Wei; Cui, Jing; Wei, Zhenggui

2014-06-01

Understanding the effects of low molecular weight organic acids (LMWOAs) on the transformation of Pb(II) to geochemically stable pyromorphite (PY) by apatite materials (AMs), has considerable benefits for risk assessment and remediation strategies for contaminated water and soil. In this study, we systematically investigated the immobilization of Pb(II) from aqueous solution by natural phosphate rock (PR) and different crystallized hydroxyapatite (HAp) in the absence and presence of LMWOAs (oxalic, malic and citric acids). The results indicated that the effectiveness of PR and HAp in immobilizing Pb(II) followed in descending order by HAp2 (the poorly crystallized HAp), HAp1 (the well crystallized HAp) and PR, regardlessof the presence of LMWOAs. The presence of malic and citric acids significantly decreased the immobilizationefficiency of Pb(II) by HAp1 and PR, clarifying the lower adsorption affinities of Pb(II)-organic acid complexes on HAp1 and PR rather than Pb(II) ion. On thecontrary, oxalic acid could markedly enhance the removal of Pb(II) from aqueous solution by HAp1 and PR through the formation of lead oxalate, which was confirmed by FT-IR and XRDanalysis. Results also showed that LMWOAs had little promoting or inhibiting effect on the immobilization of Pb(II) by HAp2. This study suggested that the ubiquity of LMWOAs in natural environments could retard the transformation efficiency of Pb(II) to PY by AMs, especiallyin thepresenceof oxalic acid, and the poorly crystallized HAp2 had great potential to remediate Pb(II)-contaminated water and soil due to its insusceptibility to LMWOAs. Copyright © 2013 Elsevier Ltd. All rights reserved.

Poplar response to cadmium and lead soil contamination.

PubMed

Radojčić Redovniković, Ivana; De Marco, Alessandra; Proietti, Chiara; Hanousek, Karla; Sedak, Marija; Bilandžić, Nina; Jakovljević, Tamara

2017-10-01

An outdoor pot experiment was designed to study the potential of poplar (Populus nigra 'Italica') in phytoremediation of cadmium (Cd) and lead (Pb). Poplar was treated with a combination of different concentrations of Cd (w = 10, 25, 50mgkg -1 soil) and Pb (400, 800, 1200mgkg -1 soil) and several physiological and biochemical parameters were monitored including the accumulation and distribution of metals in different plant parts (leaf, stem, root). Simultaneously, the changes in the antioxidant system in roots and leaves were monitored to be able to follow synergistic effects of both heavy metals. Moreover, a statistical analysis based on the Random Forests Analysis (RFA) was performed in order to determine the most important predictors affecting growth and antioxidative machinery activities of poplar under heavy metal stress. The study demonstrated that tested poplar could be a good candidate for phytoextraction processes of Cd in moderately contaminated soils, while in heavily contaminated soil it could be only considered as a phytostabilisator. For Pb remediation only phytostabilisation process could be considered. By using RFA we pointed out that it is important to conduct the experiments in an outdoor space and include environmental conditions in order to study more realistic changes of growth parameters and accumulation and distribution of heavy metals. Also, to be able to better understand the interactions among previously mentioned parameters, it is important to conduct the experiments during prolonged time exposure., This is especially important for the long life cycle woody species. Copyright © 2017. Published by Elsevier Inc.

Thallium dispersal and contamination in surface sediments from South China and its source identification.

PubMed

Liu, Juan; Wang, Jin; Chen, Yongheng; Shen, Chuan-Chou; Jiang, Xiuyang; Xie, Xiaofan; Chen, Diyun; Lippold, Holger; Wang, Chunlin

2016-06-01

Thallium (Tl) is a non-essential element in humans and it is considered to be highly toxic. In this study, the contents, sources, and dispersal of Tl were investigated in surface sediments from a riverine system (the western Pearl River Basin, China), whose catchment has been contaminated by mining and roasting of Tl-bearing pyrite ores. The isotopic composition of Pb and total contents of Tl and other relevant metals (Pb, Zn, Cd, Co, and Ni) were measured in the pyrite ores, mining and roasting wastes, and the river sediments. Widespread contamination of Tl was observed in the sediments across the river, with the highest concentration of Tl (17.3 mg/kg) measured 4 km downstream from the pyrite industrial site. Application of a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme in representative sediments unveiled that 60-90% of Tl and Pb were present in the residual fraction of the sediments. The sediments contained generally lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratios compared with the natural Pb isotope signature (1.2008 and 2.0766 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively). These results suggested that a significant fraction of non-indigenous Pb could be attributed to the mining and roasting activities of pyrite ores, with low (206)Pb/(207)Pb (1.1539) and high (208)Pb/(206)Pb (2.1263). Results also showed that approximately 6-88% of Tl contamination in the sediments originated from the pyrite mining and roasting activities. This study highlights that Pb isotopic compositions could be used for quantitatively fingerprinting the sources of Tl contamination in sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Non-destructive soil amendment application techniques on heavy metal-contaminated grassland: Success and long-term immobilising efficiency.

PubMed

Friesl-Hanl, Wolfgang; Platzer, Klaus; Riesing, Johann; Horak, Othmar; Waldner, Georg; Watzinger, Andrea; Gerzabek, Martin H

2017-01-15

Extensive contamination of grassland with cadmium (Cd), lead (Pb) and zinc (Zn) is a typical problem close to Pb/Zn smelter sites. The entry of Cd or Pb into the food chain is very likely, as are toxicity effects of Zn in plants. Previous promising results from pot and field experiments showed the high potential of using amendments for immobilisation to reduce metal input into the food chain via crops grown on smelter-contaminated soils at Arnoldstein (Austria) (Friesl et al., 2006). The aim of this study was to find a practical solution for large-scale contaminations in hilly regions that avoids erosion. Field application of amendments without destroying the vegetation cover (grassland) involved two approaches: (a) slurrying (Slu) the amendments into cut gaps in the vegetation cover and (b) injecting (Inj) the amendments through the vegetation cover. Here, we investigate the immobilising and long-term efficiency of treatments [gravel sludge (2.5%) + red mud (0.5%) (GS + RM)]. Risk assessment was based on soil, plant and water samples taken over a period of 10 years. Ammonium-nitrate-extractable Cd was reduced up to 50%, Pb up to 90%, and Zn over 90%. Plant uptake into the grass mixture and narrow leaf plantain was significantly reduced for Cd, Pb, and Zn. Harvesting early in vegetation period can further reduce uptake and meet the threshold for fodder crops. The reduction of these elements in the seepage water in 24 samplings within these 10 years reached 40%, 45% and 50%, respectively. Immobilisation increased microbial biomass and decreased human bioaccessibility for Pb. Our investigation of the long-term efficiency of GS + RM in all treatments shows that the Slu and Inj amendment application techniques have promising potential as a realistic and practical method for extensively contaminated hilly land. Slurrying performed best. We conclude that grassland remediation methods involving tillage are counterproductive from the viewpoint of bioaccessibility and soil protection and therefore should be avoided. Copyright © 2016 Elsevier Ltd. All rights reserved.

Induced Phytoextraction of Lead Through Chemical Manipulation of Switchgrass and Corn; Role of Iron Supplement.

PubMed

Johnson, Deayne M; Deocampo, Daniel M; El-Mayas, Hanan; Greipsson, Sigurdur

2015-01-01

The effects of combined chemical application of benomyl, ethylenedianinetetraacetate (EDTA), and iron (Fe) (foliar and root) on lead (Pb) phytoextraction by switchgrass (Panicum virgatum) and corn (Zea mays) was examined. Switchgrass was grown in Pb-contaminated urban topsoil with the following treatments: (C) Control, (B) benomyl, (E) EDTA, (F) foliar-Fe, (BE) benomyl + EDTA, (BF) benomyl + foliar-Fe, (FE) foliar-Fe + EDTA, (BFE) benomyl + foliar-Fe + EDTA. Corn was grown in sand-culture supplemented with Pb (500 mg kg(-1)) with the following treatments: (C) control, (B) benomyl, (E) EDTA, (F) root-Fe, (BE) benomyl + EDTA, (BF) benomyl + root-Fe, (FE) root-iron + EDTA, and, (BFE) benomyl + root-Fe + EDTA. All treatments were replicated three times and pots were arranged in a completely randomized design. Plants were analyzed for element concentration (Fe, Zn, P, and Pb) using either inductively coupled plasma (argon) atomic emission spectroscopy (ICP-AES) or graphite furnace atomic absorption spectrometer. Iron supplementation (foliar and root) affected Pb-translocation in plants. Foliar-Fe treatment increased translocation ratio of Pb (TF-Pb) significantly compared to other treatments with the exception of plants treated with benomyl and BF. Root-Fe treatment in combination with EDTA (FE) increased TF-Pb significantly compared to other treatments. Phytoextraction was improved by the combined chemical application; plants treated with BFE treatment increased Pb-total-phytoextraction by 424% compared to Control plants.

Chronic exposure to low concentrations of lead induces metabolic disorder and dysbiosis of the gut microbiota in mice.

PubMed

Xia, Jizhou; Jin, Cuiyuan; Pan, Zihong; Sun, Liwei; Fu, Zhengwei; Jin, Yuanxiang

2018-08-01

Lead (Pb) is one of the most prevalent toxic, nonessential heavy metals that can contaminate food and water. In this study, effects of chronic exposure to low concentrations of Pb on metabolism and gut microbiota were evaluated in mice. It was observed that exposure of mice to 0.1mg/L Pb, supplied via drinking water, for 15weeks increased hepatic TG and TCH levels. The levels of some key genes related to lipid metabolism in the liver increased significantly in Pb-treated mice. For the gut microbiota, at the phylum level, the relative abundance of Firmicutes and Bacteroidetes changed obviously in the feces and the cecal contents of mice exposed to 0.1mg/L Pb for 15weeks. In addition, 16s rRNA gene sequencing further discovered that Pb exposure affected the structure and richness of the gut microbiota. Moreover, a 1 H NMR metabolic analysis unambiguously identified 31 metabolites, and 15 metabolites were noticeably altered in 0.1mg/L Pb-treated mice. Taken together, the data indicate that chronic Pb exposure induces dysbiosis of the gut microbiota and metabolic disorder in mice. Chronic Pb exposure induces metabolic disorder, dysbiosis of the gut microbiota and hepatic lipid metabolism disorder in mice. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of Pseudomonas fluorescens RB4 and Bacillus subtilis 189 on the phytoremediation potential of Catharanthus roseus (L.) in Cu and Pb-contaminated soils.

PubMed

Khan, Waheed Ullah; Ahmad, Sajid Rashid; Yasin, Nasim Ahmad; Ali, Aamir; Ahmad, Aqeel

2017-06-03

The remediation of heavy metal-contaminated soils has become a critical issue due to toxic effects of these metals on living organisms. The current research was conducted to study the effect of Pseudomonas fluorescens RB4 and Bacillus subtilis 189 on the growth and phytoremediation potential of Catharanthus roseus in Cu- and Pb-contaminated soils. The bacterial strains exhibited significantly higher level of water-extractable Pb and Cu in Pb, Cu, and Cu+Pb-contaminated. The P. fluorescens RB4 inoculated plants, produced 102%, 48%, and 45% higher fresh weight (FW) in soils contaminated with Cu, Pb, and both elements, respectively, as compared to un-inoculated control plants. Similarly, B. subtilis 189 inoculated plants produced 108%, 43%, and 114% more FW in the presence of Cu, Pb, and both elements. The plants co-cultivated with both bacteria exhibited 121%, 102%, and 177% higher FW, in Cu, Pb, and both elements contaminated soils, as compared to respective un-inoculated control. Co-cultivation of P. fluorescens RB4, B. subtilis 189, and P. fluorescens RB4 + B. subtilis 189 resulted in higher accumulation of Cu and Pb in shoots of the C. roseus grown in contaminated soils as compared to un-inoculated control. Bacterial treatments also improved the translocation and metal bioconcentration factors. The growth and phytoextraction capability of C. roseus was improved by inoculation of P. fluorescens RB4 and B. subtilis 189.

Solderability of pre-tinned Cu sheet

NASA Astrophysics Data System (ADS)

Sunwoo, A. J.; Morris, J. W.; Lucey, G. K.

1992-05-01

The reliability and integrity of pre-tinned copper-clad printed circuit (PC) boards are serious concerns in the manufacture of electronic devices. The factors that influence the wetting during soldering of Cu are discussed. The results suggest that pre-tinning with a Pb-rich solder, such as 95Pb-5Sn, is preferred to pre-tinning with eutectic solder, since the latter can develop exposed intermetallics during aging that wet poorly. The results also confirm that the use of flux leads to carbon contamination in the solder.

A baseline study on the concentration of trace elements in the surface sediments off Southwest coast of Tamil Nadu, India.

PubMed

Godson, Prince S; Magesh, N S; Peter, T Simon; Chandrasekar, N; Krishnakumar, S; Vincent, Salom Gnana Thanga

2018-01-01

Forty two surface sediment samples were collected in order to document baseline elemental concentration along the Southwest coast of Tamil Nadu, India. The elements detected were Manganese (Mn), Zinc (Zn), Iron (Fe), Copper (Cu), Nickel (Ni) and Lead (Pb). The concentration of Fe and Mn was primarily controlled by the riverine input. The source of Pb and Zn is attributed to leaded petrol and anti-biofouling paints. The calculated index (EF, Igeo and CF) suggests that the sediments of the study area are significantly enriched with all elements except Pb. The contamination factor showed the order of Mn>Zn>Fe>Cu>Ni>Pb. The sediment pollution index (SPI) revealed that the sediments belonged to low polluted to dangerous category. The correlation matrix and dendrogram showed that the elemental distribution was chiefly controlled by riverine input as well as anthropogenic activity in the coast. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of candidate reference materials for the measurement of lead in bone

PubMed Central

Hetter, Katherine M.; Bellis, David J.; Geraghty, Ciaran; Todd, Andrew C.; Parsons, Patrick J.

2010-01-01

The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of 2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis. PMID:18421443

Phosphorus Amendment Efficacy for In Situ Remediation of Soil Lead Depends on the Bioaccessible Method.

PubMed

Obrycki, John F; Basta, Nicholas T; Scheckel, Kirk; Stevens, Brooke N; Minca, Kristen K

2016-01-01

A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccessible Pb in P-treated soils. Two Pb-contaminated soils (790-1300 mg Pb kg), one from a garden and one from a city lot in Cleveland, OH, were incubated in a bench scale experiment for 1 yr. Six phosphate amendments, including bone meal, fish bone, poultry litter, monoammonium phosphate, diammonium phosphate, and triple superphosphate, were added to containers at two application rates. Lead IVBA was assessed using USEPA Method 1340 and three modified versions of this method. Modifications included using solutions with pH 1.5 and 2.5 as well as using solutions with and without 0.4 mol L glycine. Soil amendments were ineffective in reducing IVBA Pb in these soils as measured by pH 1.5 with glycine buffer. The greatest reductions in IVBA Pb, from 5 to 26%, were found using pH 2.5 extractions. Lead mineral results showed several soil amendments promoted Pb phosphate formation, an indicator of remediation success. A significant negative linear relationship between reduction in IVBA Pb and Pb-phosphate formation was found only for pH 2.5 without glycine extraction solution. A modified USEPA Method 1340 without glycine and using pH 2.5 has the potential to predict P soil treatment efficacy and reductions in bioavailable Pb. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Cadmium and lead uptake by Red Swamp crayfish (Procambarus clarkii) of Louisiana

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

Naqvi, S.M.; Howell, R.D.

1993-08-01

Environmental contamination by heavy metals such as cadmium and lead is generally reflected by an increase in the tissue residues of aquatic animals. This is also true for fresh-water crayfish as reported by Bagatto and Khan (1987) for Orconectes virilis collected in the vicinity of Canadian smelters. They found a positive correlation between the residues of Cd and Pb in crayfish tissues and the distance from smelters. Stinson and Eaton reported similar findings for another crayfish, Pacifasticus leniusculus, collected from a lake on the West Coast of the US which was receiving urban runoff. Cadmium and lead were more concentratedmore » in the viscera and exoskeleton, respectively. Madigosky et al. (1991) found that Procambarus clarkii collected from roadside drainage ditches of Louisiana contained greater amounts of Cd and Pb than commercially harvested control groups. Lead accumulation has been attributed to the use of farm machinery runoff in agricultural areas and Cd to rubber tires. Cadmium and lead are known to accumulate even in those crayfish where no known contamination can be established, e.g., Dickson et al. (1980) found metal residues in troglobitic crayfish. Accumulation of Pb and Cd in the tissues in laboratory-exposed crayfish of different species has been documented by several investigators. These metals accumulate in exoskeleton, hepatopancreas, gills, antennal glands, mid-gut glands and abdominal muscles of crayfish. Generally, all studies mentioned above report metal uptake by crayfish but have not quantified the amount of metal remaining after the crayfish are transferred to uncontaminated water (depuration). The purpose of this study was to: (1) assess Cd and Pb accumulation in laboratory-exposed male and female P. clarkii (total body wet weight basis), and (2) to determine how much metal is lost when crayfish are transferred to uncontaminated aged tap water. 17 refs., 3 tabs.« less

Cadmium, lead, and zinc mobility and plant uptake in a mine soil amended with sugarcane straw biochar.

PubMed

Puga, A P; Abreu, C A; Melo, L C A; Paz-Ferreiro, J; Beesley, L

2015-11-01

Accumulation of heavy metals in unconsolidated soils can prove toxic to proximal environments, if measures are not taken to stabilize soils. One way to minimize the toxicity of metals in soils is the use of materials capable of immobilizing these contaminants by sorption. Biochar (BC) can retain large amounts of heavy metals due to, among other characteristics, its large surface area. In the current experiment, sugarcane-straw-derived biochar, produced at 700 °C, was applied to a heavy-metal-contaminated mine soil at 1.5, 3.0, and 5.0% (w/w). Jack bean and Mucuna aterrima were grown in pots containing a mine contaminated soil and soil mixed with BC. Pore water was sampled to assess the effects of biochar on zinc solubility, while soils were analyzed by DTPA extraction to confirm available metal concentrations. The application of BC decreased the available concentrations of Cd, Pb, and Zn in the mine contaminated soil leading to a consistent reduction in the concentration of Zn in the pore water. Amendment with BC reduced plant uptake of Cd, Pb, and Zn with the jack bean uptaking higher amounts of Cd and Pb than M. aterrima. This study indicates that biochar application during mine soil remediation could reduce plant concentrations of heavy metals. Coupled with this, symptoms of heavy metal toxicity were absent only in plants growing in pots amended with biochar. The reduction in metal bioavailability and other modifications to the substrate induced by the application of biochar may be beneficial to the establishment of a green cover on top of mine soil to aid remediation and reduce risks.

Pb isotope signatures in the North Atlantic: initial results from the U.S. GEOTRACES North Atlantic Transect

NASA Astrophysics Data System (ADS)

Noble, A.; Echegoyen-Sanz, Y.; Boyle, E. A.

2012-12-01

This study presents Pb isotope data from the US GEOTRACES North Atlantic Transect (US-GT-NAT) sampled during two cruises that took place during Fall 2010 and 2011. Almost all of the Pb in the modern ocean is derived from anthropogenic sources, and the North Atlantic has received major Pb inputs from the United States and Europe due to emissions from leaded gasoline and high temperature industrial processes. During the past three decades, Pb fluxes to the North Atlantic have decreased following the phasing out of leaded gasoline in the United States and Europe. Following the concentrations and isotope ratios of Pb in this basin over time reveals the temporal evolution of Pb in this highly-affected basin. The Pb isotope signatures reflect the relative importance of changing inputs from the United States and Europe as leaded gasoline was phased out faster in the United States relative to Europe. In the western North Atlantic, a shallow (~100-200m) low Pb-206/Pb-207 ratio feature was observed near the Subtropical Underwater salinity peak at many stations across the transect, coincident with shallow subsurface maxima in Pb concentration. This water mass originates from high-salinity surface water near 25°N (Defant), which is in the belt of European-Pb-gas-contaminated African aerosols, which we confirmed by Pb-206/Pb-207 ~ 1.17 from upper ocean samples from US-GT-NAT station 18 (23.24degN,38.04degW). At the Mid-Atlantic Ridge station, Pb scavenging onto iron oxides and sulfide was observed by a decrease in Pb concentrations within the TAG hydrothermal plume, although the isotopic signature within the plume was slightly (~3 permil) lower than the surrounding waters possibly indicating a small contribution of hydrothermal Pb or preferential uptake of the lighter isotope. In the Mediteranean Outflow plume near Lisbon, Pb-206/Pb-207 (~1.178) is also strongly influenced by European Pb. Further results from the section will be presented as more data will be available by the conference.

Bioabsorption of cadmium, copper and lead by the red macroalga Gelidium floridanum: physiological responses and ultrastructure features.

PubMed

dos Santos, Rodrigo W; Schmidt, Éder C; de L Felix, Marthiellen R; Polo, Luz K; Kreusch, Marianne; Pereira, Debora T; Costa, Giulia B; Simioni, Carmen; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L

2014-07-01

Heavy metals, such as lead, copper, cadmium, zinc, and nickel, are among the most common pollutants found in both industrial and urban effluents. High concentrations of these metals cause severe toxic effects, especially to organisms living in the aquatic ecosystem. Cadmium (Cd), lead (Pb) and copper (Cu) are the heavy metals most frequently implicated as environmental contaminants, and they have been shown to affect development, growth, photosynthesis and respiration, and morphological cell organization in seaweeds. This paper aimed to evaluate the effects of 50μM and 100μM of Cd, Pb and Cu on growth rates, photosynthetic pigments, biochemical parameters and ultrastructure in Gelidium floridanum. To accomplish this, apical segments of G. floridanum were individually exposed to the respective heavy metals over a period of 7 days. Plants exposed to Cd, Cu and Pb showed discoloration of thallus pigmentation, chloroplast alteration, especially degeneration of thylakoids, and decrease in photosynthetic pigments, such as chlorophyll a and phycobiliproteins, in samples treated with Cd and Cu. Moreover, cell wall thickness and the volume of plastoglobuli increased. X-ray microanalysis detected Cd, Cu and Pb absorption in the cell wall. The results indicate that Cd, Pb and Cu negatively affect metabolic performance and cell ultrastructure in G. floridanum and that Cu was more toxic than either Pb or Cd. Copyright © 2014 Elsevier Inc. All rights reserved.

Enhanced removal of lead from contaminated soil by polyol-based deep eutectic solvents and saponin.

PubMed

Mukhopadhyay, Soumyadeep; Mukherjee, Sumona; Hayyan, Adeeb; Hayyan, Maan; Hashim, Mohd Ali; Sen Gupta, Bhaskar

2016-11-01

Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.g. glycerol and ethylene glycol. A natural surfactant saponin obtained from soapnut fruit pericarp, was mixed with DESs to boost their efficiency. The DESs on their own did not perform satisfactory due to higher pH; however, they improved the performance of soapnut by up to 100%. Pb removal from contaminated soil using mixture of 40% DES-Gly and 1% saponin and mixture of 10% DES-Gly and 2% saponin were above 72% XRD and SEM studies did not detect any major corrosion in the soil texture. The environmental friendliness of both DESs and saponin and their affordable costs merit thorough investigation of their potential as soil washing agents. Copyright © 2016 Elsevier B.V. All rights reserved.

Historical records of mercury, lead, and polycyclic aromatic hydrocarbons depositions in a dated sediment core from the Eastern Mediterranean.

PubMed

Azoury, S; Tronczyński, J; Chiffoleau, J-F; Cossa, D; Nakhlé, K; Schmidt, S; Khalaf, G

2013-07-02

Depth profiles of mercury, lead and its stable isotopes, and polycyclic aromatic hydrocarbons were determined in a dated sediment core from the Levantine basin. Sedimentary records show that preindustrial fluxes and levels of Hg, Pb, and PAHs remained generally constant in the region before 1850. An almost concurrent uniform increase of both metals and PAHs deposition occurring at the beginning of the Industrial Revolution suggests coal combustion as a main source of these contaminants in the Levantine basin after the 1850s. However, none of the contaminant profiles indicates a decline after 1950-60, the characteristic period of coal use reduction. The modern fluxes of Hg and Pb reveal a 3- to 5-fold increase over preindustrial loads, while the contemporaneous flux of PAHs rises by 4-7 times. On the whole, records in the Eastern Mediterranean suggest atmospheric inputs from relatively distant sources, likely from Central and Eastern Europe.

Avoidance behavior of Eisenia fetida in oxytetracycline- and heavy metal-contaminated soils.

PubMed

Gao, Minling; Lv, Mengting; Han, Meng; Song, Wenhua; Wang, Dong

2016-10-01

To determine the behavior of oxytetracycline (OTC) and heavy metals in soil, this study assessed the pollutant-induced avoidance behavior of earthworms (E. fetida) exposed to zinc (Zn 2+ ), lead (Pb 2+ ), and OTC in soil. The results showed a clear avoidance response within 48h of exposure to the highest concentrations of pollutants. Moreover, E. fetida was shown to be more sensitive to Zn 2+ than to Pb 2+ and OTC. Compared with OTC alone, the net response of earthworms increased in the OTC-Zn 2+ and OTC-Pb 2+ combined treatments, indicating a synergistic effect. Moreover, the net response (NR) of the earthworms was higher for OTC-Zn 2+ than it was for OTC-Pb 2+ , possibly reflecting the differences in essential characteristics of Zn and Pb. Copyright © 2016 Elsevier B.V. All rights reserved.

Testing amendments for remediation of military range contaminated soil.

PubMed

Siebielec, Grzegorz; Chaney, Rufus L

2012-10-15

Military range soils are often strongly contaminated with metals. Information on the effectiveness of remediation of these soils is scarce. We tested the effectiveness of compost and mineral treatments for remediation and revegetation of military range soil collected in Aberdeen, MD. The soil was barren due to zinc (Zn) phytotoxicity while lead (Pb) posed a substantial risk to soil biota, wildlife and humans through various pathways. Seven treatments were tested: untreated control, agricultural NPK fertilization, high phosphate fertilization plus agricultural rates of NK, CaCO(3), "Orgro" biosolid compost, "Orgro" + CaCO(3), "Orgro" + CaCO(3) + Mn sulfate. All compost treatments alleviated Zn phytotoxicity to tall fescue; however compost combined with liming reduced plant Zn content up to 158-162 mg kg(-1). Compost added with lime reduced Pb in-vitro bioaccessibility from 32.5 to 20.4% of total Pb and was the most effective among the tested treatments. The study revealed the effectiveness of biosolids compost and lime mixture in the rapid stabilization of metals and revegetation of military range contaminated soils. The persistence of the remediation needs to be, however, confirmed in the long-term field study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Lead, Cadmium, Zinc, and Copper Bioavailability in the Soil-Plant-Animal System in a Polluted Area

PubMed Central

Angelova, Violina R.; Ivanova, Radka V.; Todorov, Jivko M.; Ivanov, Krasimir I.

2010-01-01

A comparative research study on the bioavailability of Pb, Cd, Zn, and Cu in the soil-plant-animal-system was carried out. The connection between the total quantity and the mobile forms of Pb, Cd, Zn, and Cu in soils with different levels of contamination; the transition of these metals into rapeseed; and their assimilation by rabbits fed with a food that consisted mainly of rapeseed was studied. It was established that the absorption of heavy metals by the rapeseed definitely has a selective character, as the affinity towards Zn is most strongly expressed. The accumulation of Pb, Cd, Zn, and Cu in the organs of the rapeseed occurs in the following order: inflorescences > leaves > stems. A direct connection between the quantity of the mobile forms and their accumulation in the plants was not found. The environmental contamination has a significant effect on heavy metal levels and distribution, as the largest quantity of all four elements is accumulated in the kidneys and liver. A well-expressed impact of the level of Cd contamination on the absorption of essential trace metals (Zn and Cu) and their accumulation into some of the organs of the animals was found. PMID:20191239

Tolerance and biosorption of copper (Cu) and lead (Pb) by filamentous fungi isolated from a freshwater ecosystem.

PubMed

Iskandar, Nur Liyana; Zainudin, Nur Ain Izzati Mohd; Tan, Soon Guan

2011-01-01

Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper (Cu) and lead (Pb). The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimum and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu(II) concentration on Potato Dextrose Agar (PDA) while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu(II) and Pb(II) that was performed by A. niger. The metal removal which occurred at Cu(II) 200 mg/L was (20.910 +/- 0.581) mg/g and at 250 mg/L of Pb(II) was (54.046 +/- 0.328) mg/g.

Quantifying statistical relationships between commonly used in vitro models for estimating lead bioaccessibility.

PubMed

Yan, Kaihong; Dong, Zhaomin; Liu, Yanju; Naidu, Ravi

2016-04-01

Bioaccessibility to assess potential risks resulting from exposure to Pb-contaminated soils is commonly estimated using various in vitro methods. However, existing in vitro methods yield different results depending on the composition of the extractant as well as the contaminated soils. For this reason, the relationships between the five commonly used in vitro methods, the Relative Bioavailability Leaching Procedure (RBALP), the unified BioAccessibility Research Group Europe (BARGE) method (UBM), the Solubility Bioaccessibility Research Consortium assay (SBRC), a Physiologically Based Extraction Test (PBET), and the in vitro Digestion Model (RIVM) were quantified statistically using 10 soils from long-term Pb-contaminated mining and smelter sites located in Western Australia and South Australia. For all 10 soils, the measured Pb bioaccessibility regarding all in vitro methods varied from 1.9 to 106% for gastric phase, which is higher than that for intestinal phase: 0.2 ∼ 78.6%. The variations in Pb bioaccessibility depend on the in vitro models being used, suggesting that the method chosen for bioaccessibility assessment must be validated against in vivo studies prior to use for predicting risk. Regression studies between RBALP and SRBC, RBALP and RIVM (0.06) (0.06 g of soil in each tube, S:L ratios for gastric phase and intestinal phase are 1:375 and 1:958, respectively) showed that Pb bioaccessibility based on the three methods were comparable. Meanwhile, the slopes between RBALP and UBM, RBALP and RIVM (0.6) (0.6 g soil in each tube, S:L ratios for gastric phase and intestinal phase are 1:37.5 and 1:96, respectively) were 1.21 and 1.02, respectively. The findings presented in this study could help standardize in vitro bioaccessibility measurements and provide a scientific basis for further relating Pb bioavailability and soil properties.

Removal of lead from aqueous solution using polyacrylonitrile/magnetite nanofibers.

PubMed

Malik, Hammad; Qureshi, Umair Ahmed; Muqeet, Muhammad; Mahar, Rasool Bux; Ahmed, Farooq; Khatri, Zeeshan

2018-02-01

Lead is known for its toxic and non-biodegradable behavior. The consumption of lead-contaminated water is one of the major threat the world is facing nowadays. In this study, polyacrylonitrile (PAN) and magnetite (Fe 3 O 4 ) composite nanofiber adsorbent was developed for Pb 2+ removal in batch mode. The synthesis was done by a simple and scalable process of electrospinning followed by chemical precipitation of Fe 3 O 4 . The nanofibers thus obtained were characterized through FTIR, zeta potential analyzer, and scanning electron microscope (SEM) and were analyzed for their adsorption capability for Pb 2+ ions. The amount of metal ion adsorbed was influenced by the initial metal ion concentration, the time the adsorbent was in contact, the amount of nanofiber, and the pH of the solution. The experimental data fitted well with pseudo 2nd-order and Langmuir adsorption isotherm model. The nanofibers showed high adsorption capability and could be recommended for Pb 2+ removal successfully.

[Bidens maximowicziana's adsorption ability and remediation potential to lead in soils].

PubMed

Wang, Hong-qi; Li, Hua; Lu, Si-jin

2005-11-01

Bidens maximowicziana's adsorption ability and remediation potential to lead were studied. The results show: (1) The Bidens maximowicziana has a strong adsorption to lead, the concentration of lead in plants increased linearly with the increase of lead concentration in soil. Then maximum concentration was 1509.3 mg x kg(-1) in roots and 2164.7 mg x kg(-1) in shoots when lead concentration in soil was 2000 mg x L(-1); (2) The lead concentration distribution order in the Bidens maximorwicziana is: leaf>stem>root>seed, which indicate that Bidens maximowicziana has a strong ability to transfer lead; (3) Uptaking ability differes in different vegetal periods. Maximum lead uptaking rate occured in the period of blooming for 40-60 days, in which daily uptake capacity was 15.81 mg x (kg x d)(-1) in roots and 19.83 mg x (kg x d)(-1) in shoots respectively. It can be concluded that Bidens maximowicziana appeares to be a moderate Pb accumulator making it suitable for phytoremediation of Pb contaminated soil.

Mobilization of lead and other trace elements following shock chlorination of wells

USGS Publications Warehouse

Seiler, R.L.

2006-01-01

Many owners of domestic wells shock chlorinate their wells to treat for bacterial contamination or control bad odors from sulfides. Analysis of well water with four wells from Fallon, Nevada, showed that following recommended procedures for shock chlorinating wells can cause large, short-lasting increases in trace-element concentrations in ground water, particularly for Cu, Fe, Pb, and Zn. Lead concentrations increased up to 745 fold between samples collected just before the well was shock chlorinated and the first sample collected 22-24??h later; Zn concentrations increased up to 252 fold, Fe concentrations increased up to 114 fold, and Cu concentrations increased up to 29 fold. Lead concentrations returned to near background levels following pumping of about one casing volume, however, in one well an estimated 120??mg of excess Pb were pumped before concentrations returned to prechlorination levels. Total Pb concentrations were much greater than filtered (0.45????m) concentrations, indicating the excess Pb is principally particulate. Recommended procedures for purging treated wells following shock chlorination may be ineffective because a strong NaOCl solution can remain in the casing above the pump even following extended pumping. Only small changes in gross alpha and beta radioactivity occurred following shock chlorination. USEPA has not promulgated drinking-water standards for 210Pb, however, measured 210Pb activities in the study area typically were less than the Canadian Maximum Acceptable Concentration of 100??mBq/L. By consuming well water shortly after shock chlorination the public may inadvertently be exposed to levels of Pb, and possibly 210Pb, that exceed drinking-water standards.

Unradiogenic Pb Anomalies in Historical Lavas of Piton de la Fournaise (Reunion Island)

NASA Astrophysics Data System (ADS)

Vlastelic, I.

2008-12-01

A detailed investigation (218 samples) of Pb isotope variations in the most recent (1975-2007), well- documented and densely sampled eruptions of Piton de la Fournaise has been undertaken (Vlastelic et al, in press). Lead isotopes exhibit smooth temporal fluctuations (18.87<206Pb/204Pb<18.94) on which superimpose rare (5), but pronounced unradiogenic spikes (206Pb/204Pb down to 17.63). In 208Pb/204Pb vs. 206Pb/204Pb space, normal and anomalous samples plot along a single linear array. In 207Pb/204Pb vs. 206Pb/204Pb space, normal samples define an array whose slope (0.16) is commonly observed in ocean island basalts, whereas anomalous samples define less steep arrays (slopes down to 0.04). It follows that some of the anomalous samples have unusually high 207Pb/204Pb for their 206Pb/204Pb. These latter are enriched in Pb by a factor three. The lack of reproducibility of isotopic analyses suggests that samples are heterogeneous at a sub-millimeter scale. The origin of the unradiogenic anomalies is enigmatic. Leaching experiments rule out anthropogenic contamination. Interaction of plume melts with a contaminant genetically unrelated to the Reunion plume is possible although not supported by trace-element and Sr-Nd isotope signatures indistinguishable from normal lavas. On the other hand, interaction with or entrainment of Pb-rich, most likely unradiogenic sulfides could affect specifically Pb isotope compositions. Inspection of the well-know eruptions history reveals that the isotopic anomalies coincide with transitions from basalts to oceanites (lavas rich in cumulative olivine). Olivine and sulfides, which are both denser than silicate melts, could be entrained with magma pulses, which give rise to high-flux oceanite eruptions. Some sulfides may originate from the oceanic crust. Others may originate from sulfide solidus depth (c.a. 160 km) where sulfides melts are expected to pond (Hart and Gaetani, 2006). These deep sulfides melts could be remnants of past melting events of the Reunion plume. References Hart, S.R., Gaetani, G.A., 2006. Contrib. Mineral. Petrol. 152, 295-308. Vlastelic, I., et al., 2008. J. Volcanol. Geotherm. Res., in press.

Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt

NASA Astrophysics Data System (ADS)

Kříbek, B.; Majer, V.; Knésl, I.; Nyambe, I.; Mihaljevič, M.; Ettler, V.; Sracek, O.

2014-11-01

The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves and washed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminated and contaminated soils of the Zambian Copperbelt mining district have been analyzed. An enrichment index (EI) was used to distinguish between contaminated and uncontaminated areas. This index is based on the average ratio of the actual and median concentration of the given contaminants (As, Co, Cu, mercury (Hg), Pb and Zn) in topsoil. The concentrations of copper in cassava leaves growing on contaminated soils reach as much as 612 mg kg-1 Cu (total dry weight [dw]). Concentrations of copper in leaves of cassava growing on uncontaminated soils are much lower (up to 252 mg kg-1 Cu dw). The concentrations of Co (up to 78 mg kg-1 dw), As (up to 8 mg kg-1 dw) and Zn (up to 231 mg kg-1 dw) in leaves of cassava growing on contaminated soils are higher compared with uncontaminated areas, while the concentrations of lead do not differ significantly. The concentrations of analyzed chemical elements in the tubers of cassava are much lower than in its leaves with the exception of As. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassava do not exceed the daily maximum tolerance limit of 0.5 mg kg-1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The highest tolerable weekly ingestion of 0.025 mg kg-1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg-1/HBW for arsenic are exceeded predominantly in the vicinity of smelters. Therefore, the preliminary assessment of dietary exposure to metals through the consumption of uncooked cassava leaves and tubers has been identified as a moderate hazard to human health. Nevertheless, as the surfaces of leaves are strongly contaminated by metalliferous dust in the polluted areas, there is still a potential hazard of ingesting dangerous levels of copper, lead and arsenic if dishes are prepared with poorly washed foliage.

Phosphorus Amendment Efficacy for In Situ Remediation of ...

EPA Pesticide Factsheets

A validated method is needed to measure reductions of in vitro bioaccessible (IVBA) Pb in urban soil remediated with amendments. This study evaluated the effect of in vitro extraction solution pH and glycine buffer on bioaccesible Pb in P-treated soils. Two Pb-contaminated soils (790-1300 mg Pb kg-1), one from a garden and one from a city lot in Cleveland, OH, were incubated in a bench scale experiment for 1 yr. Six phosphate amendments, including bone meal, fish bone, poultry litter, monoammonium phosphate, diammonium phosphate, and triple superphosphate, were added to containers at two application rates. Lead IVBA was assessed using USEPA Method 1340 and three modified versions of this method. Modifications included using solutions with pH 1.5 and 2.5 as well as using solutions with and without 0.4 mol L-1 glycine. Soil amendments were effective in reducing IVBA Pb in these soils as measured by pH 1.5 with glycine buffer. The greatest reductions in IVBA Pb, from 5 to 26%, were found using pH 2.5 extractions. Lead mineral results showed several soil amendments promoted Pb phosphate formation, an indicator of remediation success. A significant negative linear relationship between reduction in IVBA Pb and Pb-phosphate formation was found only for pH 2.5 without glycine extraction solution. A modified USEPA Method 1340 without glycine and using pH 2.5 has the potential to predict P soil treatment efficacy and reductions in bioavailable Pb. Developing mana

Assessment of a remediation technique using the replacement of contaminated soils in kitchen gardens nearby a former lead smelter in Northern France.

PubMed

Douay, F; Roussel, H; Pruvot, C; Loriette, A; Fourrier, H

2008-08-15

Vegetables cultivated in kitchen gardens that are strongly contaminated by heavy metals (Pb, Cd) may represent to consumers a means of exposure to these metals. This exposure is more problematic for those families that include a large quantity of home-grown vegetables in their diet. Researchers have shown that the majority of vegetables produced in kitchen gardens in the vicinity of the Metaleurop Nord smelter (Northern France) do not conform to European regulations. This study was carried out in three of these kitchen gardens. The concentrations of Cd and Pb in the topsoils were up to 24 and 3300 mg kg(-1) respectively. The method consisted of delineating a surface area of about 50 to 100 m(2) for each garden, then removing the contaminated soil and replacing it with a clean one. Seven species of vegetables were cultivated from 2003 to 2005 in the original contaminated soils and the remediated ones. The data showed a clear improvement of the quality of the vegetables cultivated in remediated soils, although 17% of them were still over the European legislative limits for foodstuffs. This suggested that there was a foliar contamination due to contaminated dust fallout coming from the closed smelter site and the adjacent polluted soils. In addition, the measurement of the Cd and Pb concentrations in the dust fallout showed that the substantial rise in metal concentrations in the remediated soil was not only due to atmospheric fallout. These results raise questions about possible technical, economic and sociological problems associated with this kind of remediation.

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

PubMed

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

2013-01-01

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

Stabilization of arsenic and lead by magnesium oxide (MgO) in different seawater concentrations.

PubMed

Kameda, Kentaro; Hashimoto, Yohey; Ok, Yong Sik

2018-02-01

Ongoing sea level rise will have a major impact on mobility and migration of contaminants by changing a number of natural phenomena that alter geochemistry and hydrology of subsurface environment. In-situ immobilization techniques may be a promising remediation strategy for mitigating contaminant mobility induced by sea level rise. This study investigated the reaction mechanisms of magnesium oxide (MgO) with aqueous Pb and As under freshwater and seawater using XAFS spectroscopy. Initial concentrations of Pb and As in freshwater strongly controlled the characteristics of the reaction product of MgO. Our study revealed that i) the removal of aqueous Pb and As by MgO was increased by the elevation of seawater concentration, and ii) the removal of As was attributed primarily to (inner-sphere) surface adsorption on MgO, independent on seawater concentrations, and iii) the retention mechanism of Pb was dependent on seawater concentrations where formations of Pb oxides and adsorption on the MgO surface were predominant in solutions with low and high salinity, respectively. The release of As fixed with MgO significantly increased in seawater compared to freshwater, although the amount of As desorbed accounted for <0.2% of total As. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Cook, C.M.; Lanaras, T.; Sgardelis, S.P.

The combustion of petroleum fuel and exhaust emissions are major sources of atmospheric pollution in cities which result in the deposition of toxic substances, particularly heavy metals, in the surface layers of soils. Lead in particular enters the environment from the use of tetraethyl lead as an antiknock agent for petrol engines constituting 21% of fine particles emitted from cars burning leaded petrol. Antiwear protectants incorporated in lubricants often contain Cd, Cr, Cu, Hg, Ni, Pb and/or Zn which are also released into the environment by inefficient engines and irresponsible dumping of engine oils. Zn from tyre wear and Cumore » from diesel engines also add considerably to the environmental metal burden. Lowering of the permitted lead content of petrol and the growing use of unleaded fuel are expected to lead to reductions in the environmental lead burden, however, until unleaded fuel becomes universally accepted lead contamination, particularly of roadside soils and vegetation is a major cause for concern. A direct relationship between car exhaust, the Pb content of needles of Abies alba and reduced growth has been observed and can extend hundreds of metres from major highways. Lead tolerance has been observed in higher plants growing mine waste soils and to a lesser extent on lead-contaminated roadside soils. Automobiles which are responsible for line sources of pollution emissions in rural and suburban areas have a more far-reaching impact on roadside vegetation, already under considerable stress, in urban areas. Information on heavy metal effects on vegetation in urban environments however, are scarce. Modeling and multivariate analysis of a few of the factors involved have provided only limited data related to plant performance in these complex environments. Therefore in this study, the extent of heavy metal pollution by Pb, Zn, Cu and Cd in soils and in dandelion plants in the city of Thessaloniki has been examined. 20 refs., 2 figs., 3 tabs.« less

Impact of a lead mining-smelting complex on the forest-floor litter arthropod fauna in the new lead belt region of southeast Missouri

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

Watson, A.P.; Van Hook, R.I.; Jackson, D.R.

1976-07-01

Studies of biological activity within the litter horizons of a watershed contaminated by emissions from a lead-ore processing complex focused on the litter-arthropod food chain as a means of detecting perturbations in a heavy-metal contaminated ecosystem. Both point sources (smelter stack emissions) and fugitive sources (ore-handling processes, yard dusts, and exposed concentrate piles) contributed to the Pb, Zn, Cu, and Cd levels in the study area. Arthropod trophic level density, biomass, and heavy metal content were determined by analysis of specimens removed from litter by von Tullgren funnel extraction, taxonomically classified, and segregated into the trophic categories. Changes in littermore » decomposition were reflected in the dynamics of the litter arthropod community. Food-chain dilution of Pb, Zn, Cu, and Cd from litter to litter consumer was occurring, as indicated by the mean concentration factors. Accumulation of Pb by litter consumers was much less than that found for the other three heavy metals. In contrast, predatory arthropods on Crooked Creek Watershed either concentrated or equilibrated with respect to Pb, Zn, and Cd from their prey, as indicated by mean total predator concentration factors. A significant depression of the Ca, Mg, and K content litter occurred relative to the control within 0.8 km of the stack. Two mechanisms were postulated to explain this result: increased leaching of cations through the litter induced by a loss of cation exchange capacity, a decrease in pH, and a decrease in microbial immobilization of macronutrients; and a decreased uptake of macronutrients due to root damage produced by heavy-metal concentrations.« less

Heavy metal accumulation by poplar in calcareous soil with various degrees of multi-metal contamination: implications for phytoextraction and phytostabilization.

PubMed

Hu, Yahu; Nan, Zhongren; Su, Jieqiong; Wang, Ning

2013-10-01

The object of this study was to assess the capacity of Populus alba L. var. pyramidalis Bunge for phytoremediation of heavy metals on calcareous soils contaminated with multiple metals. In a pot culture experiment, a multi-metal-contaminated calcareous soil was mixed at different ratios with an uncontaminated, but otherwise similar soil, to establish a gradient of soil metal contamination levels. In a field experiment, poplars with different stand ages (3, 5, and 7 years) were sampled randomly in a wastewater-irrigated field. The concentrations of cadmium (Cd), Cu, lead (Pb), and zinc (Zn) in the poplar tissues and soil were determined. The accumulation of Cd and Zn was greatest in the leaves of P. pyramidalis, while Cu and Pb mainly accumulated in the roots. In the pot experiment, the highest tissue concentrations of Cd (40.76 mg kg(-1)), Cu (8.21 mg kg(-1)), Pb (41.62 mg kg(-1)), and Zn (696 mg kg(-1)) were all noted in the multi-metal-contaminated soil. Although extremely high levels of Cd and Zn accumulated in the leaves, phytoextraction using P. pyramidalis may take at least 24 and 16 years for Cd and Zn, respectively. The foliar concentrations of Cu and Pb were always within the normal ranges and were never higher than 8 and 5 mg kg(-1), respectively. The field experiment also revealed that the concentrations of all four metals in the bark were significantly higher than that in the wood. In addition, the tissue metal concentrations, together with the NH4NO3-extractable concentrations of metals in the root zone, decreased as the stand age increased. P. pyramidalis is suitable for phytostabilization of calcareous soils contaminated with multiple metals, but collection of the litter fall would be necessary due to the relatively high foliar concentrations of Cd and Zn.

Trace Metal Inventories and Lead Isotopic Composition Chronicle a Forest Fire’s Remobilization of Industrial Contaminants Deposited in the Angeles National Forest

PubMed Central

Odigie, Kingsley O.; Flegal, A. Russell

2014-01-01

The amounts of labile trace metals: [Co] (3 to 11 µg g−1), [Cu] (15 to 69 µg g−1), [Ni] (6 to 15 µg g−1), [Pb] (7 to 42 µg g−1), and [Zn] (65 to 500 µg g−1) in ash collected from the 2012 Williams Fire in Los Angeles, California attest to the role of fires in remobilizing industrial metals deposited in forests. These remobilized trace metals may be dispersed by winds, increasing human exposures, and they may be deposited in water bodies, increasing exposures in aquatic ecosystems. Correlations between the concentrations of these trace metals, normalized to Fe, in ash from the fire suggest that Co, Cu, and Ni in most of those samples were predominantly from natural sources, whereas Pb and Zn were enriched in some ash samples. The predominantly anthropogenic source of excess Pb in the ash was further demonstrated by its isotopic ratios (208Pb/207Pb: 206Pb/207Pb) that fell between those of natural Pb and leaded gasoline sold in California during the previous century. These analyses substantiate current human and environmental health concerns with the pyrogenic remobilization of toxic metals, which are compounded by projections of increases in the intensity and frequency of wildfires associated with climate change. PMID:25259524

Geochemical sources of metal contamination in a coal mining area in Chhattisgarh, India using lead isotopic ratios.

PubMed

Das, Avijit; Patel, Subhra Sarita; Kumar, Rajeev; Krishna, K V S S; Dutta, Saikat; Saha, Manik Chandra; Sengupta, Siladitya; Guha, Dipayan

2018-04-01

A geochemical study of the trace metals and lead isotopic ratios of soil and sediments in Korba, Chhattisgarh, India is presented here for the first time. Korba, the nation's 'power hub' is also the fifth among its eighty-eight most critically polluted industrial hotspots. A very high mean concentration (in mg kg-1) of V (308), Cr (567), Mn (3442), Co (92), Cu (218), Zn (426), Pb (311), Th (123) and U (32) characterized the sediments of the studied area with mean I geo values of the trace metals ranging from -2.29 to 3.27. In the two-ratio scatter Pb isotope plot of the different environmental matrices, except for human blood, coal, soil, sediments, non-washed leaves, flyash and diesel overlapped linearly in the mixing line between diesel as the highest anthropogenic end member and a core sediment fraction representing its geogenic counterpart. The mean 207 Pb/ 206 Pb Pb ratio decreased in the order of diesel (0.9012) > flyash (0.8757) > coal (0.8498) soils and sediments (0.8374) > lowest core sediment fraction (0.8017). Principal Component Analysis (PCA) of the trace metal data extracted V, Cr, Cu, Zn, Pb, U and Th in the first component PC1. The northeastern part of the study area revealed major hotspots of V, Cu, Co, Zn and Pb near the flyash dykes of the power stations. Human blood used as a biomarker for Pb pollution in this study had a mean blood lead level of 28 μg/dl with a distinctive high 207 Pb/ 206 Pb ratio of 0.8828. Published by Elsevier Ltd.

Heavy metals hazards from Nigerian spices.

PubMed

Asomugha, Rose Ngozi; Udowelle, Nnaemeka Arinze; Offor, Samuel James; Njoku, Chinonso Judith; Ofoma, Ifeoma Victoria; Chukwuogor, Chiaku Chinwe; Orisakwe, Orish Ebere

Natural spices are commonly used by the people in Nigeria. They may be easily contaminated with heavy metals when they are dried and then pose a health risk for the consumers. The aim of this study was to determine the levels of heavy metals in some commonly consumed natural spices namely Prosopis Africana, Xylopia aethiopica, Piper gineense, Monodora myristica, Monodora tenuifolia and Capsicum frutescens sold in the local markets of Awka, Anambra state, South East Nigeria to estimate the potential health risk. The range of heavy metal concentration was in the order: Zn (14.09 - 161.04) > Fe (28.15 - 134.59) > Pb (2.61 - 8.97) > Cr (0.001 - 3.81) > Co (0.28 - 3.07) > Ni (0.34 - 2.89). Pb, Fe and Zn exceeded the maximum allowable concentrations for spices. The Target Hazard Quotient (THQ) of the spices varied from 0.06-0.5. Estimated daily intakes (EDI) were all below the tolerable daily intake (TDI). The lead levels in Prosopis africana, Xylopia aethiopica, Piper gineense, Monodora myristica and Capsicum frutescens which are 8-30 times higher than the WHO/FAO permissible limit of 0.3 mg/kg. Lead contamination of spices sold in Awka (south east Nigeria) may add to the body burden of lead. A good quality control for herbal food is important in order to protect consumers from contamination. food products, spices, potential toxic metals, risk assessment, public health.

Elevated CO2 benefits the soil microenvironment in the rhizosphere of Robinia pseudoacacia L. seedlings in Cd- and Pb-contaminated soils.

PubMed

Huang, Shuping; Jia, Xia; Zhao, Yonghua; Bai, Bo; Chang, Yafei

2017-02-01

Soil contamination by heavy metals in combination with elevated atmospheric CO 2 has important effects on the rhizosphere microenvironment by influencing plant growth. Here, we investigated the response of the R. pseudoacacia rhizosphere microenvironment to elevated CO 2 in combination with cadmium (Cd)- and lead (Pb)-contamination. Organic compounds (total soluble sugars, soluble phenolic acids, free amino acids, and organic acids), microbial abundance and activity, and enzyme activity (urease, dehydrogenase, invertase, and β-glucosidase) in rhizosphere soils increased significantly (p < 0.05) under elevated CO 2 relative to ambient CO 2 ; however, l-asparaginase activity decreased. Addionally, elevated CO 2 alone affected soil microbial community in the rhizosphere. Heavy metals alone resulted in an increase in total soluble sugars, free amino acids, and organic acids, a decrease in phenolic acids, microbial populations and biomass, and enzyme activity, and a change in microbial community in rhizosphere soils. Elevated CO 2 led to an increase in organic compounds, microbial populations, biomass, and activity, and enzyme activity (except for l-asparaginase), and changes in microbial community under Cd, Pb, or Cd + Pb treatments relative to ambient CO 2 . In addition, elevated CO 2 significantly (p < 0.05) enhanced the removal ratio of Cd and Pb in rhizosphere soils. Overall, elevated CO 2 benefited the rhizosphere microenvironment of R. pseudoacacia seedlings under heavy metal stress, which suggests that increased atmospheric CO 2 concentrations could have positive effects on soil fertility and rhizosphere microenvironment under heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Remediation of Pb/Cr co-contaminated soil using electrokinetic process and approaching electrode technique.

PubMed

Ng, Yee-Sern; Sen Gupta, Bhaskar; Hashim, Mohd Ali

2016-01-01

Electrokinetic process has emerged as an important tool for remediating heavy metal-contaminated soil. The process can concentrate heavy metals into smaller soil volume even in the absence of hydraulic flow. This makes it an attractive soil pre-treatment method before other remediation techniques are applied such that the chemical consumption in the latter stage can be reduced. The present study evaluates the feasibility of electrokinetic process in concentrating lead (Pb) and chromium (Cr) in a co-contaminated soil using different types of wetting agents, namely 0.01 M NaNO3, 0.1 M citric acid and 0.1 M EDTA. The data obtained showed that NaNO3 and citric acid resulted in poor Pb electromigration in this study. As for Cr migration, these agents were also found to give lower electromigration rate especially at low pH region as a result of Cr(VI) adsorption and possible reduction into Cr(III). In contrast, EDTA emerged as the best wetting agent in this study as it formed water-soluble anionic complexes with both Pb and Cr. This provided effective one-way electromigration towards the anode for both ions, and they were accumulated into smaller soil volume with an enrichment ratio of 1.55-1.82. A further study on the application of approaching cathode in EDTA test showed that soil alkalisation was achieved, but this did not provide significant enhancement on electromigration for Pb and Cr. Nevertheless, the power consumption for electrokinetic process was decreased by 22.5%.

Leaching of Cu, Cd, Pb, and phosphorus and their availability in the phosphate-amended contaminated soils under simulated acid rain.

PubMed

Cui, Hongbiao; Zhang, Shiwen; Li, Ruyan; Yi, Qitao; Zheng, Xuebo; Hu, Youbiao; Zhou, Jing

2017-09-01

Phosphate amendments have been used to immobilize heavy metal-contaminated soils. However, phosphate amendments contain large amounts of phosphorus, which could leach out to potentially contaminate groundwater and surface water. A laboratory column leaching experiment was designed to study the effects of simulated acid rain (SAR) on the potential release of copper (Cu), lead (Pb), cadmium (Cd), and phosphorus (P), and their availability after immobilizing with hydroxyapatite (HAP) and potassium dihydrogen phosphate (PDP). The application of HAP and PDP enhanced the leachate electrical conductivity, total organic carbon, and pH. Higher P was found in the PDP- (>4.29 mg L -1 ) and HAP-treated (>1.69 mg L -1 ) columns than that in untreated (<0.2 mg L -1 ) columns, and they were both over the class V limit (0.4 mg L -1 ) mandated by the Chinese National Quality Standards for Surface Waters (GB 3838-2002). PDP application decreased the leachate Cu, Pb, and Cd effectively; however, HAP addition increased leachate Cu and Pb. HAP and PDP applications decreased the soil CaCl 2 -extractable and exchangeable fraction of Cu, Pb, and Cd, and increased resin P. However, eluviations transformed the heavy metals from inactive to active fractions and reduced soil labile P. These findings showed that HAP and PDP had a potential risk of excessive P-induced eutrophication. Meanwhile, more attention should be paid to the leaching loss of multiple metals because phosphate amendments might promote the leaching of some metals while immobilizing others.

Lead isotopic evidence for mixed sources of Proterozoic granites and pegmatites, Black Hills, South Dakota, USA

NASA Astrophysics Data System (ADS)

Krogstad, Eirik J.; Walker, Richard J.; Nabelek, Peter I.; Russ-Nabelek, Carol

1993-10-01

The lead isotopic compositions of K-feldspars separated from the ca. 1700 Ma Harney Peak Granite complex and spatially associated granitic pegmatites indicate that these rocks were derived from at least two sources. It has been reported previously that the core of the Harney Peak Granite complex is dominated by relatively lower/ gd18O (avg. 11.5 %.) granites, whereas higher / gd18O (avg. 13.2%.) granites occur around the periphery of the complex. The higher δ 18O granites and one simple pegmatite have low values of 207Pb /204Pb for their 206Pb /204Pb Thus, they likely were derived from a source with a short crustal residence time. This source may have been the pelitic schists into which the Harney Peak Granite complex and pegmatites were intruded. Feldspars from granites with lower / gd18O values have significantly higher 207Pb /204Pb for their 206Pb /204Pb . The data define a linear array with a slope equivalent to an age of ca. 2.6 Ga with t 2 defined to be 1.7 Ga. Such a slope could represent a mixing array or a secondary isochron for the source. These low δ18O granites could have been derived from a source with a high U/ Pb and with a crustal residence beginning before the Proterozoic. The source (s) of these granites may have been a sediment derived from late Archean continental crust. The highly evolved Tin Mountain pegmatite has lead isotopic systematics intermediate between those of the two granite groups, suggesting either a mixed source or contamination. Two late Archean granites, the Little Elk Granite and the Bear Mountain Granite, had precursors with high U/Pb and low Th/U histories. The Th/U history of the Bear Mountain Granite is too low for this rock to have been an important component of the source of the Proterozoic granites. However, crustal rocks with lead isotopic compositions similar to those of the Little Elk Granite were an important source of lead for some of the Proterozoic granitic rocks.

Contaminated lead environments of man: reviewing the lead isotopic evidence in sediments, peat, and soils for the temporal and spatial patterns of atmospheric lead pollution in Sweden.

PubMed

Bindler, Richard

2011-08-01

Clair Patterson and colleagues demonstrated already four decades ago that the lead cycle was greatly altered on a global scale by humans. Moreover, this change occurred long before the implementation of monitoring programs designed to study lead and other trace metals. Patterson and colleagues also developed stable lead isotope analyses as a tool to differentiate between natural and pollution-derived lead. Since then, stable isotope analyses of sediment, peat, herbaria collections, soils, and forest plants have given us new insights into lead biogeochemical cycling in space and time. Three important conclusions from our studies of lead in the Swedish environment conducted over the past 15 years, which are well supported by extensive results from elsewhere in Europe and in North America, are: (1) lead deposition rates at sites removed from major point sources during the twentieth century were about 1,000 times higher than natural background deposition rates a few thousand years ago (~10 mg Pb m(-2) year(-1) vs. 0.01 mg Pb m(-2) year(-1)), and even today (~1 mg Pb m(-2) year(-1)) are still almost 100 times greater than natural rates. This increase from natural background to maximum fluxes is similar to estimated changes in body burdens of lead from ancient times to the twentieth century. (2) Stable lead isotopes ((206)Pb/(207)Pb ratios shown in this paper) are an effective tool to distinguish anthropogenic lead from the natural lead present in sediments, peat, and soils for both the majority of sites receiving diffuse inputs from long range and regional sources and for sites in close proximity to point sources. In sediments >3,500 years and in the parent soil material of the C-horizon, (206)Pb/(207)Pb ratios are higher, 1.3 to >2.0, whereas pollution sources and surface soils and peat have lower ratios that have been in the range 1.14-1.18. (3) Using stable lead isotopes, we have estimated that in southern Sweden the cumulative anthropogenic burden of atmospherically deposited lead is ~2-5 g Pb m(-2) and ~1 g Pb m(-2) in the "pristine" north. Half of this cumulative total was deposited before industrialization. (4) In the vicinity of the Rönnskär smelter in northern Sweden, a major point source during the twentieth century, there is an isotopic pattern that deviates from the general trends elsewhere, reflecting the particular history of ore usage at Rönnskär, which further demonstrates the chronological record of lead loading recorded in peat and in soil mor horizons.

Combined effects of low-molecular-weight organic acids on mobilization of arsenic and lead from multi-contaminated soils.

PubMed

Onireti, Olaronke O; Lin, Chuxia; Qin, Junhao

2017-03-01

A batch experiment was conducted to examine the combined effects of three common low-molecular-weight organic acids (LMWOAs) on the mobilization of arsenic and lead in different types of multi-contaminated soils. The capacity of individual LMWOAs (at a same molar concentration) to mobilize soil-borne As and Pb varied significantly. The combination of the organic acids did not make a marked "additive" effect on the mobilization of the investigated three elements. An "antagonistic" effect on element mobilization was clear in the treatments involving oxalic acid for some soils. The acid strength of a LMWOA did not play an important role in controlling the mobilization of elements. While the mobilization of As and Pb was closely associated with the dissolution of soil-borne Fe, soil properties such as original soil pH, organic matter contents and the total amount of the element relative to the total Fe markedly complicated the mobility of that element. Aging led to continual consumption of proton introduced from addition of LMWOAs and consequently caused dramatic changes in solution-borne Fe, which in turn resulted in change in As and Pb in the soil solution though different elements behaved differently. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitation of lead-210 (210Pb) using lead-203 (203Pb) as a "Massless" yield tracer.

PubMed

May, D; Nelson, A N; Schultz, M K

2017-05-01

Determination of Pb-210 ( 210 Pb) in aqueous solution is a common radioanalytical challenge in environmental science. Widely used methods for undertaking these analyses (e.g., ASTM D7535) rely on the use of stable lead (Pb) as a yield tracer that takes into account losses of 210 Pb that inevitably occur during elemental/radiochemical separations of the procedures. Although effective, these methods introduce technical challenges that can be difficult to track and potentially introduce uncertainty that can be difficult to quantify. Examples of these challenges include interference from endogenous stable Pb in complex sample matrices; contamination of stable Pb carrier with 210 Pb; and high detection limits due to counting efficiency limitations. We hypothesized that many of these challenges could be avoided by the use of the electron-capture, gamma-emitting isotope, 203 Pb as a chemical yield tracer in the analysis of 210 Pb. A series of experiments were performed to evaluate the efficacy of 203 Pb as a tracer. Four different matrices were analyzed, including a complex matrix (hydraulic-fracturing produced fluids); and samples comprising less complicated matrices (i.e., river water, deionized water, and tap water). Separation techniques and counting methodologies were also compared and optimized. Due to a relatively short-half life (52 h), 203 Pb tracer is effectively massless for the purposes of chemical separations, allowing for reduced chromatography column resin bed volumes. Because 203 Pb is a gamma emitter (279 keV; 81% intensity), recovery can be determined non-destructively in a variety of matrices, including liquid scintillation cocktail. The use of liquid scintillation as a counting methodology allowed for determination of 210 Pb activities via 210 Pb or 210 Po; and recoveries of greater than 90% are routinely achievable using this approach. The improved method for the analysis of 210 Pb in aqueous matrices allows for the analysis of complex matrices, at reduced cost, while providing greater counting flexibility in achieving acceptable detections limits. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of soil properties on the toxicity of Pb: assessment of the appropriateness of guideline values.

PubMed

Romero-Freire, A; Martin Peinado, F J; van Gestel, C A M

2015-05-30

Soil contamination with lead is a worldwide problem. Pb can cause adverse effects, but its mobility and availability in the terrestrial environment are strongly controlled by soil properties. The present study investigated the influence of different soil properties on the solubility of lead in laboratory spiked soils, and its toxicity in three bioassays, including Lactuca sativa root elongation and Vibrio fischeri illumination tests applied to aqueous extracts and basal soil respiration assays. Final aim was to compare soil-dependent toxicity with guideline values. The L. sativa bioassay proved to be more sensitive to Pb toxicity than the V. fischeri and soil respiration tests. Toxicity was significantly correlated with soil properties, with soil pH, carbonate and organic carbon content being the most important factors. Therefore, these variables should be considered when defining guideline values. Copyright © 2015 Elsevier B.V. All rights reserved.

Multi-functional sorbents for the simultaneous removal of sulfur and lead compounds from hot flue gases.

PubMed

Zhao, Yi; Lin, Wen-Chiang

2003-10-01

A multi-functional sorbent is developed for the simultaneous removal of PbCl(2) vapor and sulfur dioxide from the combustion gases. The sorbent is tested in a bench-scale reactor at the temperature of 700 degrees C, using simulated flue gas (SFG) containing controlled amounts of PbCl(2) and SO(2) compounds. The removal characteristics of PbCl(2) and SO(2), individually and in combination, are investigated. The results show that the mechanism of capture by the sorbent is not a simple physical adsorption process but seems to involve a chemical reaction between the Ca-based sorbent and the contaminants from the simulated flue gas. The porous product layer in the case of individual SO(2) sorption is in a molten state at the reaction temperature. In contrast, the combined sorption of lead and sulfur compounds generates a flower-shaped polycrystalline product layer.

Relationship between Pb and Cd accumulations in house crow, their habitat, and food content from Klang area, Peninsular Malaysia.

PubMed

Janaydeh, Mohammed; Ismail, Ahmad; Omar, Hishamuddin; Zulkifli, Syaizwan Zahmir; Bejo, Mohd Hair; Aziz, Nor Azwady Abd

2017-12-27

Heavy metal pollution has become a global concern due to accumulation in tissue and transferable effects to humans via the food chain. This study focused on monitoring the accumulation of cadmium (Cd) and lead (Pb) in surface soil and body content: bone, heart, brain, liver, lung, muscle, kidney, feathers, feces, and gizzard contents of house crow Corvus splendens in the Klang region, Malaysia. The results revealed the occurrence of Pb and Cd in all biological samples from house crows, food contents, and surface soil samples. Heart and kidney accrued high amounts of Cd, while high amounts of Pb were found to accumulate in bones and feathers. Major discrepancies were also discovered in the concentrations of metals between juvenile and adults, as well as female and male bird samples. Concentrations of Pb and Cd in house crow internal tissues correlated significantly with that of bird feathers, but none could be established with that of surface soil. In addition, a significant correlation was observed between Pb concentration in the internal tissues to that of the feces, but the same was not the case when compared with the surface soil concentration. Metal accrual in the house crows feathers and feces may be through a long-term transmission via the food chain, which are eliminated from feathers via molting. This may suggest the utility of molted breast feathers of house crow in the bio-monitoring of Cd and Pb contamination, whereas feces of house crow appear only to be suitable for the bio-monitoring of Pb contamination.

Metal contamination of soils and crops affected by the Chenzhou lead/zinc mine spill (Hunan, China).

PubMed

Liu, Hongyu; Probst, Anne; Liao, Bohan

2005-03-01

In 1985, the collapse of the tailing dam in Chenzhou lead/zinc mine (Hunan, southern China) led to the spread of mining waste spills on the farmland along the Dong River. After the accident, an urgent soil cleaning up was carried out in some places. Seventeen years later, cereal (rice, maize, and sorghum), pulses (soybean, Adzuki bean, mung bean and peanut), vegetables (ipomoea, capsicum, taro and string bean) and the rooted soils were sampled at four sites: (1) the mining area (SZY), (2) the area still covered with the mining tailing spills (GYB), (3) the cleaned area from mining tailing spills (JTC), and (4) a background site (REF). Metal concentrations in the crops and soils were analyzed to evaluate the long-term effects of the spilled waste on the soil and the potential human exposure through food chains. The results showed that the physical-chemical properties of the soils obviously changed due to the different farming styles used by each individual farmer. Leaching effects and plant extraction of metals from some soils were quite weak. Certain soils were still heavily polluted with As, Cd, Zn, Pb and Cu. The contamination levels were in the order of GYB>SZY>JTC showing that the clean-up treatment was effective. The maximum allowable concentration (MAC) levels for Chinese agricultural soils were still highly exceeded, particularly for As and Cd (followed by Zn, Pb and Cu), with mean concentrations of 709 and 7.6 mg kg(-1), respectively. These concentrations exceed the MAC levels by 24 times for As and 13 times for Cd at GYB. Generally, the edible leaves or stems of crops were more heavily contaminated than seeds or fruits. Ipomoea was the most severely contaminated crop. The concentrations of Cd and Pb were 3.30 and 76.9 mg kg(-1) in ipomoea leaves at GYB, which exceeded the maximum permit levels (0.5 mg kg(-1) for Cd and 9 mg kg(-1) for Pb) by 6.6 and 8.5 times, respectively. Taro (+skin) could accumulate high concentrations of Zn and Cd in the edible stem, and rice and capsicum had high Cd concentration in the edible parts. However, the toxic element concentrations in maize, sorghum, Adzuki bean, soybean and mung bean remained lower than the threshold levels. The bio-accumulation factors (BAFs) of crops were in the order: Cd>Zn>Cu>Pb>As. BAF was typically lower in the edible seeds or fruits than in stems and leaves. The accumulation effect strongly depends on the crop's physiological properties, the mobility, of the metals, and the availability of metals in soils but not entirely on the total element concentrations in the soils. Even so, the estimated daily intake amount of Cu, Zn, Cd, and Pb from the crops grown in the affected three sites and arsenic at SZY and GYB exceeded the RDA (Recommended dietary allowance) levels. Subsequently, the crops grown in Chenzhou Pb/Zn mine waste affected area might have a hazardous effect on the consumer's health. This area still needs effective measures to cure the As, Cd, Pb, Zn and Cu contamination.

Transport, ultrastructural localization, and distribution of chemical forms of lead in radish (Raphanus sativus L.).

PubMed

Wang, Yan; Shen, Hong; Xu, Liang; Zhu, Xianwen; Li, Chao; Zhang, Wei; Xie, Yang; Gong, Yiqin; Liu, Liwang

2015-01-01

Lead (Pb), a ubiquitous but highly toxic heavy metal (HM), is harmful to human health through various pathways including by ingestion of contaminated vegetables. Radish is a worldwide root vegetable crop with significant health and nutritional benefits. However, little is known about Pb translocation and distribution within radish plants after its uptake by the roots. In this study, Pb stress was induced using Pb(NO3)2 in hydroponic culture, aiming to characterize the transport, ultrastructural localization, and distribution of chemical forms of Pb in different tissues of radish. The results showed that the majority of Pb (85.76-98.72%) was retained in underground organs including lateral roots, root heads and taproot skins, while a small proportion of Pb was absorbed by root flesh (0.44-1.56%) or transported to the shoot (1.28-14.24%). A large proportion of Pb (74.11-99.30%) was integrated with undissolved Pb oxalate, protein and pectates forming Pb-phosphate complexes. Moreover, a low-Pb-accumulating line of radish showed a higher proportion of Pb in water-soluble form compared with a high-Pb-accumulating line. Subcellular distribution analysis showed that a large proportion of Pb was bound to cell wall fraction in lateral roots (71.08-80.40%) and taproot skin (46.22-77.94%), while the leaves and roots had 28.36-39.37% and 27.35-46.51% of Pb stored in the soluble fraction, respectively. Furthermore, transmission electron microscopy (TEM) revealed Pb precipitates in intercellular space, cell wall, plasma lemma and vacuoles. Fractionation results also showed the accumulation of Pb on the cell wall, intercellular space and vacuole, and low uptake of undissolved Pb oxalate, protein, pectates and Pb-phosphate complexes, which might be due to low transport efficiency and Pb tolerance of radish. These findings would provide insight into molecular mechanism of Pb uptake and translocation in radish and facilitate development of low-Pb-content cultivars in root vegetable crops.

Accumulation of Zn, Cd, Cu, and Pb in Chinese cabbage as influenced by climatic conditions under protected cultivation.

PubMed

Moreno, Diego A; Víllora, Gemma; Hernández, Joaquín; Castilla, Nicolás; Romero, Luis

2002-03-27

Accumulation of heavy metals from agricultural soils contaminated by low levels heavy metals has important implications in the understanding of heavy metal contamination in the food chain. Through field experiments (1994-1996), the influence of thermal regime under different treatments on the accumulation of zinc, cadmium, copper, and lead in Chinese cabbage [Brassica pekinensis (Lour) Rupr. cv. Nagaoka 50] grown in a Calcareous Fluvisol (Xerofluvent) in Granada (southern Spain) was examined. Two floating row covers were used: T(1) (perforated polyethylene, 50 microm thick) and T(2) (17 g m(-2) polypropylene nonwoven fleece). An uncovered cultivation (T(0)) served as control. Zn, Cd, Cu, and Pb levels in the whole tops of experimental plants were analyzed. Treatments T(1) and T(2) gave rise to differences in environmental conditions with respect to T(0). The influence of environmental factors manipulated by floating row covers (particularly under T(1)) increased total heavy metal accumulation in the above ground plant biomass with respect to the open-air crop. The total contents of Zn, Cd, Cu, and Pb were 30, 50, 90, and 40% higher in T(1), respectively, than in T(0). This technique could be used in contaminated zones for different plant species because the thermal effect favors the process of phytoextraction and thus reduces the contamination.