Effects of cadmium, manganese, and lead on locomotor activity and neurexin 2a expression in zebrafish.

PubMed

Tu, Hongwei; Fan, Chengji; Chen, Xiaohui; Liu, Jiaxian; Wang, Bin; Huang, Zhibin; Zhang, Yiyue; Meng, Xiaojing; Zou, Fei

2017-08-01

The synaptic adhesion protein Neurexin 2a (Nrxn2a) plays a key role in neuronal development and is associated with cognitive functioning and locomotor behavior. Although low-level metal exposure poses a potential risk to the human nervous system, especially during the developmental stages, little is known about the effects of metal exposures on nrxn2a expression during embryonic development. We therefore exposed wild-type zebrafish embryos/larvae to cadmium (CdCl 2 ), manganese (MnCl 2 ), and lead ([CH 3 COO] 2 Pb), to determine their effect on mortality, malformation, and hatching rate. Concentrations of these metals in zebrafish were detected by inductively coupled plasma mass spectrometry analysis. Locomotor activity of zebrafish larvae was analyzed using a video-track tracking system. Expression of nrxn2a was assessed by in situ hybridization and quantitative polymerase chain reaction. The results showed that mortality, malformation, and bioaccumulation increased as the exposure dosages and duration increased. Developmental exposure to these metals significantly reduced larval swim distance and velocity. The nrxn2aa and nrxn2ab genes were expressed in the central nervous system and downregulated by almost all of the 3 metals, especially Pb. These data demonstrate that exposure to metals downregulates nrxn2a in the zebrafish model system, and this is likely linked to concurrent developmental processes. Environ Toxicol Chem 2017;36:2147-2154. © 2017 SETAC. © 2017 SETAC.

PM2.5-bound metal metabolic distribution and coupled lipid abnormality at different developmental windows.

PubMed

Ku, Tingting; Zhang, Yingying; Ji, Xiaotong; Li, Guangke; Sang, Nan

2017-09-01

Atmospheric fine particulate matter (PM 2.5 ) is a serious threat to human health. As a toxicant constituent, metal leads to significant health risks in a population, but exposure to PM 2.5 -bound metals and their biological impacts are not fully understood. In this study, we determined the metal contents of PM 2.5 samples collected from a typical coal-burning city and then investigated the metabolic distributions of six metals (Zn, Pb, Mn, As, Cu, and Cd) following PM 2.5 inhalation in mice in different developmental windows. The results indicate that fine particles were mainly deposited in the lung, but PM 2.5 -bound metals could reach and gather in secondary off-target tissues (the lung, liver, heart and brain) with a developmental window-dependent property. Furthermore, elevations in triglycerides and cholesterol levels in sensitive developmental windows (the young and elderly stages) occurred, and significant associations between metals (Pb, Mn, As and Cd) and cholesterol in the heart, brain, liver and lung were observed. These findings suggest that PM 2.5 inhalation caused selective metal metabolic distribution in tissues with a developmental window-dependent property and that the effects were associated with lipid alterations. This provides a foundation for the underlying systemic toxicity following PM 2.5 exposure based on metal components. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of developmental lead exposure on splenic factors

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

Kasten-Jolly, Jane, E-mail: kjolly@wadsworth.or; Heo, Yong, E-mail: yheo@cu.ac.k; Lawrence, David A., E-mail: david.lawrence@wadsworth.or

2010-09-01

Lead (Pb) is known to alter the functions of numerous organ systems, including the hematopoietic and immune systems. Pb can induce anemia and can lower host resistance to bacterial and viral infections. The anemia is due to Pb's inhibition of hemoglobin synthesis and Pb's induction of membrane changes, leading to early erythrocyte senescence. Pb also increases B-cell activation/proliferation and skews T-cell help (Th) toward Th2 subset generation. The specific mechanisms for many of the Pb effects are, as yet, not completely understood. Therefore, we performed gene expression analysis, via microarray, on RNA from the spleens of developmentally Pb-exposed mice, inmore » order to gain further insight into these Pb effects. Splenic RNA microarray analysis indicated strong up-regulation of genes coding for proteolytic enzymes, lipases, amylase, and RNaseA. The data also showed that Pb affected the expression of many genes associated with innate immunity. Analysis of the microarray results via GeneSifter software indicated that Pb increased apoptosis, B-cell differentiation, and Th2 development. Direct up-regulation by Pb of expression of the gene encoding the heme-regulated inhibitor (HRI) suggested that Pb can decrease erythropoiesis by blocking globin mRNA translation. Pb's high elevation of digestive/catabolizing enzymes could generate immunogenic self peptides. With Pb's potential to induce new self-peptides and to enhance the expression of caspases, cytokines, and other immunomodulators, further evaluation of Pb's involvement in autoimmune phenomena, especially Th2-mediated autoantibody production, and alteration of organ system activities is warranted.« less

New directions in the toxicokinetics of human lead exposure

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

Mushak, P.

An important determinant of body lead (Pb) burden and Pb toxicity in exposed humans is Pb metabolism, or more correctly, Pb toxicokinetics. It affects the former through the quantitative processes of uptake, distribution and retention/excretion and the latter via delivery of toxic doses to cellular/molecular sites of action. Pb toxicokinetics has useful application in understanding Pb's behavior in populations. Several of these applications have been studied and results are presented for the toxicokinetic basis of dose-neurotoxic effect relationships in selected longitudinal studies and the use of toxicokinetic modeling for estimation of body lead burden in early populations. Three well-known, ongoingmore » longitudinal studies of developmental neurotoxicity--in Boston, Cincinnati, and Port Pirie, Australia--involve cohorts who differ markedly as to their pre- and postnatal lead exposure profiles. Toxicokinetic examination of these exposure differences helps to explain the temporal variability seen in blood Pb-toxic effect relationships and supports a causal role for lead. Toxicokinetic models of Pb uptake and in-vivo behavior are increasingly being considered for estimating Pb-B levels in lieu of direct measurement. A linear biokinetic model, using reliable input data for natural/prehistoric levels of Pb in sources, was applied to estimation of prehistoric/preindustrial children's blood lead. A range of 0.06 to 0.12 microgram/dl was estimated for two lead intakes. These estimates are still two orders of magnitude (85 to 165-fold) lower than the newly issued CDC toxicity guideline for children of 10 micrograms/dl. Lastly, the toxicokinetics of lead in bone, particularly its resorption with metabolic stimuli, is of concern, particularly for baby boom women who are either of childbearing age or approaching menopause and who had greatly elevated environmental lead exposures in the 1940s to 1970s. 115 refs.« less

Elevated lead levels from e-waste exposure are linked to decreased olfactory memory in children.

PubMed

Zhang, Bo; Huo, Xia; Xu, Long; Cheng, Zhiheng; Cong, Xiaowei; Lu, Xueling; Xu, Xijin

2017-12-01

Lead (Pb) is a developmental neurotoxicant and can cause abnormal development of the nervous system in children. Hence, the aim of this study was to investigate the effect of Pb exposure on child olfactory memory by correlating the blood Pb levels of children in Guiyu with olfactory memory tests. We recruited 61 preschool children, 4- to 7-years of age, from Guiyu and 57 children from Haojiang. The mean blood Pb level of Guiyu children was 9.40 μg/dL, significantly higher than the 5.04 μg/dL mean blood Pb level of Haojiang children. In addition, approximately 23% of Guiyu children had blood Pb levels exceeding 10.00 μg/dL. The correlation analysis showed that blood Pb levels in children highly correlated with e-waste contact (r s  = 0.393). Moreover, the mean concentration of serum BDNF in Guiyu children (35.91 ng/ml) was higher than for Haojiang (28.10 ng/ml) and was positively correlated with blood Pb levels. Both item and source olfactory memory tests at 15 min, 5 h and 24 h after odor exposure showed that scores were lower in Guiyu children indicative of reduced olfactory memory in Guiyu children. Olfactory memory tests scores negatively correlated with blood Pb and serum BDNF levels, but were positively associated with parental education levels. At the same time, scores of both tests on children in the high blood Pb level group (blood Pb levels > 5.00 μg/dL) were lower than those in the low blood Pb level group (blood Pb levels ≤ 5.00 μg/dL), implying that Pb exposure decreases olfactory memory in children. Our findings suggest that Pb exposure in e-waste recycling and dismantling areas could result in an increase in serum BDNF level and a decrease in child olfactory memory, in addition, BDNF might be involved in olfactory memory impairment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hearing loss in children with e-waste lead and cadmium exposure.

PubMed

Liu, Yu; Huo, Xia; Xu, Long; Wei, Xiaoqin; Wu, Wengli; Wu, Xianguang; Xu, Xijin

2018-05-15

Environmental chemical exposure can cause neurotoxicity and has been recently linked to hearing loss in general population, but data are limited in early life exposure to lead (Pb) and cadmium (Cd) especially for children. We aimed to evaluate the association of their exposure with pediatric hearing ability. Blood Pb and urinary Cd were collected form 234 preschool children in 3-7years of age from an electronic waste (e-waste) recycling area and a reference area matched in Shantou of southern China. Pure-tone air conduction (PTA) was used to test child hearing thresholds at frequencies of 0.25, 0.5, 1, 2, 4 and 8kHz. A PTA≥25dB was defined as hearing loss. A higher median blood Pb level was found in the exposed group (4.94±0.20 vs 3.85±1.81μg/dL, p<0.001), while no significance was found for creatinine-adjusted Cd. Compared with the reference group, the exposed group had a higher prevalence of hearing loss (28.8% vs 13.6%, p<0.001). The PTA in the left, right and both ears, and hearing thresholds at average low and high frequency, and single frequency of 0.5, 1 and 2kHz were all increased in the exposed group. Positive correlations of child age and nail biting habit with Pb, and negative correlations of parent education level and child washing hands before dinner with Pb and Cd exposure were observed. Logistic regression analyses showed the adjusted OR of hearing loss for Pb exposure was 1.24 (95% CI: 1.029, 1.486). Our data suggest that early childhood exposure to Pb may be an important risk factor for hearing loss, and the developmental auditory system might be affected in e-waste polluted areas. Copyright © 2017 Elsevier B.V. All rights reserved.

The influence of environmental exposure to complex mixtures including PAHs and lead on genotoxic effects in children living in Upper Silesia, Poland.

PubMed

Mielzyńska, Danuta; Siwińska, Ewa; Kapka, Lucyna; Szyfter, Krzysztof; Knudsen, Lisbeth E; Merlo, Domenico Franco

2006-09-01

Environmental exposure is a complex mixture of hazardous compounds with different mechanisms of toxicity. In case of concomitant exposure to carcinogenic substances--such as polycyclic aromatic hydrocarbons (PAHs)--and to heavy metals--such as lead (Pb)--the level of DNA damage may be enhanced. Children are considered more vulnerable than adults to chemical toxicants because they take in more toxicants as a proportion of body mass and because of inherent biological growth and developmental factors. The objective of the study was to measure cytogenetic effects in Silesian children and to investigate their relation with the environmental exposure to PAHs and Pb. The examined population included 74 children 5-14-year-old who lived in two cities located in the most polluted centre of the Silesia province. Individual exposure to lead was assessed for each child by measuring lead in blood (PbB), and to PAH by measuring 1-hydroxypyrene in urine (1-OHP), urinary mutagenicity and DNA adducts in circulating lymphocytes. Biomarkers of genetic effects were assessed by measuring micronuclei (MN) and sister chromatid exchanges (SCE) in children's peripheral lymphocytes. The mean levels of biomarkers of exposure were as follows: PbB 7.69 microg/dl, DNA adducts 9.59 adducts per 10(8) nt, 1-OHP 0.54 micromol/mol creatinine, and urinary mutagenicity presented as the number of revertants per mmol of creatinine: 485 for TA 98 and 1318 for YG1024. Mean value of MN was 4.44 per 1000 binucleated cells and SCE frequency ranged between 6.24 and 10.06 with a mean value of 7.87. The results suggest the influence of exposure to environmental agents on the induction of cytogenetic effects in peripheral lymphocytes of children: namely Pb on MN and PAHs on SCE. The sources of that exposure may be outdoor and indoor. Emissions from coal-burning stoves are important contributors to the total exposure to PAHs and Pb in Silesian children.

Associations between metals in residential environmental media and exposure biomarkers over time in infants living near a mining-impacted site

PubMed Central

Zota, Ami R.; Riederer, Anne M.; Ettinger, Adrienne S.; Schaider, Laurel A.; Shine, James P.; Amarasiriwardena, Chitra J.; Wright, Robert O.; Spengler, John D.

2017-01-01

Infant exposures to metals are a concern for mining-impacted communities, although limited information is available to assess residential exposures over the first year of life. We measured lead (Pb), manganese, arsenic, and cadmium in indoor air, house dust, yard soil, and tap water from 53 infants’ homes near the Tar Creek Superfund Site (Oklahoma, USA) at two time points representing developmental stages before and during initial ambulation (age 0–6 and 6–12 months). We measured infant metal biomarkers in: umbilical cord blood (n = 53); 12- (n = 43) and 24- (n = 22) month blood; and hair at age 12 months (n = 39). We evaluated cross-sectional and longitudinal associations between infant residential and biomarker concentrations. A doubling of mean dust Pb concentration was consistently associated with 36–49% higher 12-month blood Pb adjusting for cord blood Pb (P≤ 0.05). Adjusted dust concentration explained 29–35% of blood Pb variance, and consistent associations with other media were not observed. Although concentrations in dust and blood were generally low, strong and consistent associations between dust and body burden suggest that house dust in mining-impacted communities may impact children’s health. These relationships were observed at a young age, typically before blood Pb levels peak and when children’s development may be particularly vulnerable to toxic insult. PMID:26648247

Associations between metals in residential environmental media and exposure biomarkers over time in infants living near a mining-impacted site.

PubMed

Zota, Ami R; Riederer, Anne M; Ettinger, Adrienne S; Schaider, Laurel A; Shine, James P; Amarasiriwardena, Chitra J; Wright, Robert O; Spengler, John D

2016-09-01

Infant exposures to metals are a concern for mining-impacted communities, although limited information is available to assess residential exposures over the first year of life. We measured lead (Pb), manganese, arsenic, and cadmium in indoor air, house dust, yard soil, and tap water from 53 infants' homes near the Tar Creek Superfund Site (Oklahoma, USA) at two time points representing developmental stages before and during initial ambulation (age 0-6 and 6-12 months). We measured infant metal biomarkers in: umbilical cord blood (n=53); 12- (n=43) and 24- (n=22) month blood; and hair at age 12 months (n=39). We evaluated cross-sectional and longitudinal associations between infant residential and biomarker concentrations. A doubling of mean dust Pb concentration was consistently associated with 36-49% higher 12-month blood Pb adjusting for cord blood Pb (P⩽0.05). Adjusted dust concentration explained 29-35% of blood Pb variance, and consistent associations with other media were not observed. Although concentrations in dust and blood were generally low, strong and consistent associations between dust and body burden suggest that house dust in mining-impacted communities may impact children's health. These relationships were observed at a young age, typically before blood Pb levels peak and when children's development may be particularly vulnerable to toxic insult.

Genome-wide expression and methylation profiling in the aged rodent brain due to early-life Pb exposure and its relevance to aging.

PubMed

Dosunmu, Remi; Alashwal, Hany; Zawia, Nasser H

2012-06-01

In this study, we assessed global gene expression patterns in adolescent mice exposed to lead (Pb) as infants and their aged siblings to identify reprogrammed genes. Global expression on postnatal day 20 and 700 was analyzed and genes that were down- and up-regulated (≥2 fold) were identified, clustered and analyzed for their relationship to DNA methylation. About 150 genes were differentially expressed in old age. In normal aging, we observed an up-regulation of genes related to the immune response, metal-binding, metabolism and transcription/transduction coupling. Prior exposure to Pb revealed a repression in these genes suggesting that disturbances in developmental stages of the brain compromise the ability to defend against age-related stressors, thus promoting the neurodegenerative process. Overexpression and repression of genes corresponded with their DNA methylation profile. Published by Elsevier Ireland Ltd.

Transgenerational endocrine disruption and neurotoxicity in zebrafish larvae after parental exposure to binary mixtures of decabromodiphenyl ether (BDE-209) and lead.

PubMed

Chen, Lianguo; Wang, Xianfeng; Zhang, Xiaohua; Lam, Paul K S; Guo, Yongyong; Lam, James C W; Zhou, Bingsheng

2017-11-01

Polybrominated diphenyl ethers (PBDEs) and heavy metals are two key groups of electric and electronic equipment contaminants. Despite their co-occurrence in aquatic environments, their combined effects remain largely unknown, particularly under a chronic exposure regime. In the present study, adult zebrafish (Danio rerio) were exposed to environmentally relevant concentrations of BDE-209 and lead (Pb), or their binary mixtures, for 3 months. After chronic parental exposure, increased transfer of BDE-209 and Pb to the offspring eggs was activated in the coexposure groups, with BDE-197 being the predominant PBDE congener, indicating the dynamic metabolism of BDE-209 in parental zebrafish. In the presence of Pb, culturing the eggs in clean water until 5 days post-fertilization (dpf) further accelerated the debromination of BDE-209 towards BDE-197 in the offspring, caused by the preferential removal of bromine atoms at meta positions. BDE-209 and Pb combinations induced reproductive and thyroid endocrine disruption in adults, which resulted in an imbalanced deposition of hormones in the eggs. However, compared with single chemical exposure, the larval offspring at 5 dpf from the coexposure groups had reversed the adverse influences from maternal origin. In addition, the interaction between BDE-209 and Pb led to transgenerational developmental neurotoxicity in the larval offspring, where inhibited neuronal growth and neurotransmitter signaling, disorganized muscular assembly, and impaired visual function contributed to the observed neurobehavioral deficits. Overall, depending on specific biological events, the complex interaction between BDE-209 and Pb under chronic exposure resulted in significant alterations in their environmental fate and toxicological actions, thus complicating the accurate evaluation of ecological risks and constituting an unquantified threat to environmental safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

NTP monograph on health effects of low-level lead.

PubMed

2012-06-01

Although reductions in lead (Pb) exposure for the U.S. population have resulted in lower blood Pb levels over time, epidemiological studies continue to provide evidence of health effects at lower and lower blood Pb levels. Low-level Pb was selected for evaluation by the National Toxicology Program (NTP) because of (1) the availability of a large number of epidemiological studies of Pb, (2) a nomination by the National Institute for Occupational Safety and Health for an assessment of Pb at lower levels of exposure, and (3) public concern for effects of Pb in children and adults. This evaluation summarizes the evidence in humans and presents conclusions on health effects in children and adults associated with low-level Pb exposure as indicated by less than 10 micrograms of Pb per deciliter of blood (< 10 microg/dL). The assessment focuses on epidemiological evidence at blood Pb levels < 10 microg/dL and < 5 microg/dL because health effects at higher blood Pb levels are well established. The NTP evaluation was conducted through the Office of Health Assessment and Translation (OHAT, formerly the Center for the Evaluation of Risks to Human Reproduction) and completed in April of 2012. The results of this evaluation are published in the NTP Monograph on Health Effects of Low-Level Lead. The document and appendices are available at http://ntp.niehs.nih.gov/go/evals. This document provides background on Pb exposure and includes a review of the primary epidemiological literature for evidence that low-level Pb is associated with neurological, immunological, cardiovascular, renal, and/or reproductive and developmental effects. The NTP Monograph presents specific conclusions for each health effect area. Overall, the NTP concludes that there is sufficient evidence that blood Pb levels < 10 microg/dL and < 5 microg/dL are associated with adverse health effects in children and adults. This conclusion was based on a review of the primary epidemiological literature, scientific input from technical advisors that reviewed pre-public release drafts of each chapter summarizing the evidence for specific health effects associated with low-level Pb, public comments received during the course of the evaluation, and comments from an expert panel of ad hoc reviewers during a public meeting to review the Draft NTP Monograph on November 17-18, 2011 (http://ntp.niehs.nih.gov/go/37090.

Presynaptic mechanisms of lead neurotoxicity: effects on vesicular release, vesicle clustering and mitochondria number.

PubMed

Zhang, Xiao-Lei; Guariglia, Sara R; McGlothan, Jennifer L; Stansfield, Kirstie H; Stanton, Patric K; Guilarte, Tomás R

2015-01-01

Childhood lead (Pb2+) intoxication is a global public health problem and accounts for 0.6% of the global burden of disease associated with intellectual disabilities. Despite the recognition that childhood Pb2+ intoxication contributes significantly to intellectual disabilities, there is a fundamental lack of knowledge on presynaptic mechanisms by which Pb2+ disrupts synaptic function. In this study, using a well-characterized rodent model of developmental Pb2+ neurotoxicity, we show that Pb2+ exposure markedly inhibits presynaptic vesicular release in hippocampal Schaffer collateral-CA1 synapses in young adult rats. This effect was associated with ultrastructural changes which revealed a reduction in vesicle number in the readily releasable/docked vesicle pool, disperse vesicle clusters in the resting pool, and a reduced number of presynaptic terminals with multiple mitochondria with no change in presynaptic calcium influx. These studies provide fundamental knowledge on mechanisms by which Pb2+ produces profound inhibition of presynaptic vesicular release that contribute to deficits in synaptic plasticity and intellectual development.

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.

Blood mercury, lead and cadmium levels and determinants of exposure among newcomer South and East Asian women of reproductive age living in Vancouver, Canada.

PubMed

Dix-Cooper, Linda; Kosatsky, Tom

2018-04-01

Biomarkers of the reproductive and neuro-developmental toxicants mercury (Hg), lead (Pb) and cadmium (Cd) have been found at higher concentrations in women born outside Canada than in Canadian-born women. We measured blood Hg, Pb and Cd in women ages 19 to 45years living in greater Vancouver (Canada) within five years of their arrival from South Asia (India) or East Asia (mainland China, Hong Kong and Taiwan) and related their biomarker concentration levels with exposures and behaviors since their coming to Canada. Participants were recruited through advertisements in relevant ethnic media, locations and groups. Concentrations of blood Hg, Pb and Cd were analyzed by inductively coupled plasma-mass spectrometry (ICP-Q-MS) and compared with population values. Biomarker concentrations were regressed against exposures and behaviors assessed by culturally-relevant questionnaire. The study recruited 53 South and 111 East Asian women. Median (95th percentile) blood Pb in South Asians was 1.15 (2.71) μg/dL compared with 1.01 (1.81) μg/dL in East Asians. On the other hand, blood Hg at 2.5 (7.3) μg/L was higher in East Asians compared to 0.20 (0.83) μg/L in South Asians. Blood Cd was also higher in the East Asian group: East 0.53 (1.1) μg/L; South 0.27 (0.82) μg/L. Higher blood Hg was associated with seafood consumption, dental amalgams and traditional remedies; blood Pb with home renovations, sucking on metal jewelry, and cosmetics. Blood Pb and Cd concentrations were inversely associated with dairy consumption. Asian women recently arrived in Vancouver had higher blood Hg, Pb and Cd concentrations than same-age Canadian women measured in a national survey. Among South Asian newcomer women of reproductive age, exposure to Cd may continue after arrival. Local exposures to Hg occur through seafood and potentially through ingestion of imported traditional remedies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Gestational lead exposure induces developmental abnormalities and up-regulates apoptosis of fetal cerebellar cells in rats.

PubMed

Mousa, Alyaa M; Al-Fadhli, Ameera S; Rao, Muddanna S; Kilarkaje, Narayana

2015-01-01

Lead (Pb), a known environmental toxicant, adversely affects almost all organ systems. In this study, we investigated the effects of maternal lead exposure on fetal rat cerebellum. Female Sprague-Dawley rats were given lead nitrate in drinking water (0, 0.5, and 1%) for two weeks before conception, and during pregnancy. Fetuses were collected by caesarian section on gestational day 21 and observed for developmental abnormalities. The fetal cerebellar sections from control and 1% lead group were stained with cresyl violet. Immunohistochemical expressions of p53, Bax, Bcl-2, and caspase 3 were quantified by AnalySIS image analyzer (Life Science, Germany). Lead exposure induced developmental abnormalities of eyes, ear, limbs, neck and ventral abdominal wall; however, these abnormalities were commonly seen in the 1% lead-treated group. In addition, lead also caused fetal mortality and reduced body growth in both dose groups and reduced brain weight in the 1% lead-treated group. The fetal cerebella from the 1% lead-treated group showed unorganized cerebellar cortical layers, and degenerative changes in granule and Purkinje cells such as the formation of clumps of Nissl granules. An increase in Bax and caspase 3, and a decrease in Bcl-2 (p < 0.05), but not in p53, showed apoptosis of the neurons. In conclusion, gestational lead exposure in rats induces fetal toxicity and developmental abnormalities. The lead exposure also impairs development of cerebellar layers, induces structural changes, and apoptosis in the fetal cerebellar cortex. These results suggest that lead exposure during gestation is extremely toxic to developing cerebellum in rats.

Experimental design affects social behavior outcomes in adult zebrafish developmentally exposed to lead.

PubMed

Weber, Daniel N; Ghorai, Jugal K

2013-09-01

Lead (Pb(2+)) affects neuronal and endocrine systems that influence social interactions. By providing potential hiding locations, spatial heterogeneity may affect Pb(2+)-induced behavioral outcomes. Therefore, a test chamber was designed into which a refuge could be inserted. The refuge allowed test subjects to escape from the mirror image that stimulated agonistic interactions. Behaviors with a mirror were compared with baseline activity patterns without a mirror. Adult (12-month old) male and female zebrafish, exposed to Pb(2+) (0-10 μM) as embryos (2-24 hours post fertilization), were tested individually for 5 min in each chamber design within 2 h of feeding. Behaviors were evaluated for % time in mirror zone, distance traveled (=activity level), and attacks on the mirror image. When there was no refuge, significant concentration-dependent increases occurred in male % time in mirror zone, activity level, and number of attacks. Increases in these variables were less pronounced in females. When there was a refuge, there were significant differences for males only in activity level and attacks at the higher developmental exposure concentrations; % time in mirror zone followed a similar pattern and level as without refuge. Females displayed Pb(2+)-induced behavioral changes only for attacks on mirror. Since the presence of refuges that is, environmental enrichment, reduced Pb(2+)-induced agonistic behavior in both sexes, experimental spatial design can be considered an important factor when interpreting behavioral outcomes.

Highly selective and sensitive coumarin-triazole-based fluorometric 'turn-off' sensor for detection of Pb2+ ions.

PubMed

Shaily; Kumar, Ajay; Parveen, Iram; Ahmed, Naseem

2018-06-01

Exposure to even very low concentrations of Pb 2+ is known to cause cardiovascular, neurological, developmental, and reproductive disorders, and affects children in particular more severely. Consequently, much effort has been dedicated to the development of colorimetric and fluorescent sensors that can selectively detect Pb 2+ ions. Here, we describe the development of a triazole-based fluorescent sensor L5 for Pb 2+ ion detection. The fluorescence intensity of chemosensor L5 was selectively quenched by Pb 2+ ions and a clear color change from colorless to yellow could be observed by the naked eye. Chemosensor L5 exhibited high sensitivity and selectivity towards Pb 2+ ions in phosphate-buffered solution [20 mM, 1:9 DMSO/H 2 O (v/v), pH 8.0] with a 1:1 binding stoichiometry, a detection limit of 1.9 nM and a 6.76 × 10 6  M -1 binding constant. Additionally, low-cost and easy-to-prepare test strips impregnated with chemosensor L5 were also produced for efficient of Pb 2+ detection and proved the practical use of this test. Copyright © 2018 John Wiley & Sons, Ltd.

Is Lead Exposure in Early Life An Environmental Risk Factor for Schizophrenia? Neurobiological Connections and Testable Hypotheses

PubMed Central

Guilarte, Tomás R.; Opler, Mark; Pletnikov, Mikhail

2013-01-01

Schizophrenia is a devastating neuropsychiatric disorder of unknown etiology. There is general agreement in the scientific community that schizophrenia is a disorder of neurodevelopmental origin in which both genes and environmental factors come together to produce a schizophrenia phenotype later in life. The challenging questions have been which genes and what environmental factors? Although there is evidence that different chromosome loci and several genes impart susceptibility for schizophrenia; and epidemiological studies point to broad aspects of the environment, only recently there has been an interest in studying gene × environment interactions. Recent evidence of a potential association between prenatal lead (Pb2+) exposure and schizophrenia precipitated the search for plausible neurobiological connections. The most promising connection is that in schizophrenia and in developmental Pb2+ exposure there is strong evidence for hypoactivity of the N-methyl-d-aspartate (NMDA) subtype of excitatory amino acid receptors as an underlying neurobiological mechanism in both conditions. A hypofunction of the NMDA receptor (NMDAR) complex during critical periods of development may alter neurobiological processes that are essential for brain growth and wiring, synaptic plasticity and cognitive and behavioral outcomes associated with schizophrenia. We also describe on-going proof of concept gene-environment interaction studies of early life Pb2+ exposure in mice expressing the human mutant form of the disrupted in schizophrenia 1 (DISC-1) gene, a gene that is strongly associated with schizophrenia and allied mental disorders. PMID:22178136

Uncovering neurodevelopmental windows of susceptibility to manganese exposure using dentine microspatial analyses.

PubMed

Claus Henn, Birgit; Austin, Christine; Coull, Brent A; Schnaas, Lourdes; Gennings, Chris; Horton, Megan K; Hernández-Ávila, Mauricio; Hu, Howard; Téllez-Rojo, Martha Maria; Wright, Robert O; Arora, Manish

2018-02-01

Associations between manganese (Mn) and neurodevelopment may depend on dose and exposure timing, but most studies cannot measure exposure variability over time well. We apply temporally informative tooth-matrix biomarkers to uncover windows of susceptibility in early life when Mn is associated with visual motor ability in childhood. We also explore effect modification by lead (Pb) and child sex. Participants were drawn from the ELEMENT (Early Life Exposures in MExico and NeuroToxicology) longitudinal birth cohort studies. We reconstructed dose and timing of prenatal and early postnatal Mn and Pb exposures for 138 children by analyzing deciduous teeth using laser ablation-inductively coupled plasma-mass spectrometry. Neurodevelopment was assessed between 6 and 16 years of age using the Wide Range Assessment of Visual Motor Abilities (WRAVMA). Mn associations with total WRAVMA scores and subscales were estimated with multivariable generalized additive mixed models. We examined Mn interactions with Pb and child sex in stratified models. Levels of dentine Mn were highest in the second trimester and declined steeply over the prenatal period, with a slower rate of decline after birth. Mn was positively associated with visual spatial and total WRAVMA scores in the second trimester, among children with lower (< median) tooth Pb levels: one standard deviation (SD) increase in ln-transformed dentine Mn at 150 days before birth was associated with a 0.15 [95% CI: 0.04, 0.26] SD increase in total score. This positive association was not observed at high Pb levels. In contrast to the prenatal period, significant negative associations were found in the postnatal period from ~ 6 to 12 months of age, among boys only: one SD increase in ln-transformed dentine Mn was associated with a 0.11 [95% CI: - 0.001, - 0.22] to 0.16 [95% CI: - 0.04, - 0.28] SD decrease in visual spatial score. Using tooth-matrix biomarkers with fine scale temporal profiles of exposure, we found discrete developmental windows in which Mn was associated with visual-spatial abilities. Our results suggest that Mn associations are driven in large part by exposure timing, with beneficial effects found for prenatal levels and toxic effects found for postnatal levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Geochemical Legacies and the Future Health of Cities: An Analysis of two Neurotoxins in Urban Soils

NASA Astrophysics Data System (ADS)

Filippelli, G. M.; Risch, M.

2015-12-01

The past and future of cities are inextricably linked, a linkage that can be seen clearly in the long-term impacts of urban geochemical legacies. As loci of population as well as the means of employment and industry to support these populations, cities have a long history of co-locating contaminating practices and people, sometimes with negative implications for human health. Working at the intersection between geochemical processes, communities, and human health is critical to grapple with environmental legacies and to support healthy, sustainable, and growing urban populations. An emerging area of environmental health research is to understand the impacts of chronic exposures and exposure mixtures—these impacts are very poorly studied, yet have materialized as perhaps the greatest threat to large-scale population health. 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 these legacy Pb sources are still around in the form of surface soil Pb contamination, a common problem in cities and one that has only recently emerged as a pernicious and widespread chronic exposure mechanism in cities. Some urban soils are also contaminated with another neurotoxin, mercury (Hg), although very little work has been done to understand human exposures to low levels of this element in soils. The most documented human exposure to Hg is through fish consumption, so eating fish caught in urban areas presents risks for above average dietary Hg exposure. The potential double impact of chronic exposure to these two neurotoxins is pronounced in cities. Many aspects of the dose-response curves for individual elements and mixtures are poorly understood, especially at lower levels, leaving unanswered several interesting and provocative questions about environmental impacts on neurological and developmental disorders.

Tracking natural and anthropogenic Pb exposure to its geological source.

PubMed

Evans, Jane; Pashley, Vanessa; Madgwick, Richard; Neil, Samantha; Chenery, Carolyn

2018-01-31

Human Pb exposure comes from two sources: (i) natural uptake through ingestion of soils and typified by populations that predate mining activity and (ii) anthropogenic exposure caused by the exposure to Pb derived from ore deposits. Currently, the measured concentration of Pb within a sample is used to discriminate between these two exposure routes, with the upper limit for natural exposure in skeletal studies given as 0.5 or 0.7 mg/kg in enamel and 0.5/0.7 μg/dL in blood. This threshold approach to categorising Pb exposure does not distinguish between the geological origins of the exposure types. However, Pb isotopes potentially provide a more definitive means of discriminating between sources. Whereas Pb from soil displays a crustal average 238 U/ 204 Pb (μ) value of c 9.7, Pb from ore displays a much wider range of evolution pathways. These characteristics are transferred into tooth enamel, making it possible to characterize human Pb exposure in terms of the primary source of ingested Pb and to relate mining activity to geotectonic domains. We surmise that this ability to discriminate between silicate and sulphide Pb exposure will lead to a better understanding of the evolution of early human mining activity and development of exposure models through the Anthropocene.

Pb exposure attenuates hypersensitivity in vivo by increasing regulatory T cells

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

Fang, Liang; Zhao, Fang; Shen, Xuefeng

Pb is a common environmental pollutant affecting various organs. Exposure of the immune system to Pb leads to immunosuppression or immunodysregulation. Although previous studies showed that Pb exposure can modulate the function of helper T cells, Pb immunotoxicity remains incompletely understood. In this study, we investigated the effect of Pb exposure on T cell development, and the underlying mechanism of Pb-induced suppression of the delayed-type hypersensitivity (DTH) response in vivo. Sprague–Dawley rats were exposed to 300 ppm Pb-acetate solution via the drinking water for six weeks, and we found that Pb exposure significantly increased Pb concentrations in the blood bymore » 4.2-fold (p < 0.05) as compared to those in the control rats. In Pb-exposed rats, the amount of thymic CD4{sup +}CD8{sup −} and peripheral CD4{sup +} T cells was significantly reduced, whereas, CD8{sup +} population was not affected. In contrast to conventional CD4{sup +} T cells, Foxp3{sup +} regulatory T cells (Tregs) were increased in both the thymus and peripheral lymphoid organs of Pb-exposed rats. In line with the increase of Tregs, the DTH response of Pb-exposed rats was markedly suppressed. Depletion of Tregs reversed the suppression of DTH response by Pb-exposed CD4{sup +} T cells in an adoptive transfer model, suggesting a critical role of the increased Tregs in suppressing the DTH response. Collectively, this study revealed that Pb-exposure may upregulate Tregs, thereby leading to immunosuppression. -- Highlights: ► Pb exposure impaired CD4{sup +} thymic T cell development. ► Peripheral T lymphocytes were reduced following Pb exposure. ► Pb exposure increases thymic and peripheral Treg cells in rats. ► Tregs played a critical role in Pb-exposure-induced immune suppression.« less

Metabolism of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) Atropisomers in Tissue Slices from Phenobarbital or Dexamethasone-Induced Rats is Sex-Dependent

PubMed Central

Wu, Xianai; Kania-Korwel, Izabela; Chen, Hao; Stamou, Marianna; Dammanahalli, Karigowda J.; Duffel, Michael; Lein, Pamela J.; Lehmler, Hans-Joachim

2013-01-01

Chiral polychlorinated biphenyls (PCBs) such as PCB 136 enantioselectively sensitize the ryanodine receptor (RyR). In light of recent evidence that PCBs cause developmental neurotoxicity via RyR-dependent mechanisms, this suggests that enantioselective PCB metabolism may influence the developmental neurotoxicity of chiral PCBs. However, enantioselective disposition of PCBs has not been fully characterized.The effect of sex and cytochrome P450 (P450) enzyme induction on the enantioselective metabolism of PCB 136 was studied using liver tissue slices prepared from naïve control (CTL), phenobarbital (PB; CYP2B inducer) or dexamethasone (DEX; CYP3A inducer) pretreated adult Sprague-Dawley rats. PCB 136 metabolism was also examined in hippocampal slices derived from untreated rat pups.In liver tissue slices, hydroxylated PCB (OH-PCB) profiles depended on sex and inducer pretreatment, and OH-PCB levels followed the rank orders male > female and PB > DEX > CTL. In contrast, the enantiomeric enrichment of PCB 136 and its metabolites was independent of sex and inducer pretreatment. Only small amounts of PCB 136 partitioned into hippocampal tissue slices and no OH-PCB metabolites were detected.Our results suggest that enantioselective metabolism, sex and induction status of P450 enzymes in the liver may modulate the neurotoxic outcomes of developmental exposure to chiral PCBs. PMID:23581876

Alzheimer’s Disease and Environmental Exposure to Lead: The Epidemiologic Evidence and Potential Role of Epigenetics

PubMed Central

Bakulski, Kelly M.; Rozek, Laura S.; Dolinoy, Dana C.; Paulson, Henry L.; Hu, Howard

2013-01-01

Several lines of evidence indicate that the etiology of late-onset Alzheimer’s disease (LOAD) is complex, with significant contributions from both genes and environmental factors. Recent research suggests the importance of epigenetic mechanisms in defining the relationship between environmental exposures and LOAD. In epidemiologic studies of adults, cumulative lifetime lead (Pb) exposure has been associated with accelerated declines in cognition. In addition, research in animal models suggests a causal association between Pb exposure during early life, epigenetics, and LOAD. There are multiple challenges to human epidemiologic research evaluating the relationship between epigenetics, LOAD, and Pb exposure. Epidemiologic studies are not well-suited to accommodate the long latency period between exposures during early life and onset of Alzheimer’s disease. There is also a lack of validated circulating epigenetics biomarkers and retrospective biomarkers of Pb exposure. Members of our research group have shown bone Pb is an accurate measurement of historical Pb exposure in adults, offering an avenue for future epidemiologic studies. However, this would not address the risk of LOAD attributable to early-life Pb exposures. Future studies that use a cohort design to measure both Pb exposure and validated epigenetic biomarkers of LOAD will be useful to clarify this important relationship. PMID:22272628

Whole-Body Lifetime Occupational Lead Exposure and Risk of Parkinson’s Disease

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

Coon , Steven; Stark, Azadeh; Peterson, Edward

2006-12-01

We enrolled 121 PD patients and 414 age-, sex-, and race-, frequency-matched controls in a case–control study. As an indicator of chronic Pb exposure, we measured concentrations of tibial and calcaneal bone Pb stores using 109Cadmium excited K-series X-ray fluorescence. As an indicator of recent exposure, we measured blood Pb concentration. We collected occupational data on participants from 18 years of age until the age at enrollment, and an industrial hygienist determined the duration and intensity of environmental Pb exposure. We employed physiologically based pharmacokinetic modeling to combine these data, and we estimated whole-body lifetime Pb exposures for each individual.more » Logistic regression analysis produced estimates of PD risk by quartile of lifetime Pb exposure.« less

Heavy metal exposure has adverse effects on the growth and development of preschool children.

PubMed

Zeng, Xiang; Xu, Xijin; Qin, Qilin; Ye, Kai; Wu, Weidong; Huo, Xia

2018-04-25

The purpose of this study was to investigate the associations between levels of lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn) in the PM 2.5 and blood and physical growth, and development parameters including birth length and weight, height, weight, body mass index (BMI), head circumference, and chest circumference in preschool children from Guiyu (e-waste exposure area) and Haojiang (the reference area). A total of 470 preschool children from Guiyu and Haojiang located in southeast coast of China were recruited and required to undergo physical examination and blood tests during the study period. Birth length and weight were obtained by birth records and questionnaire. Pb and Cd in both PM 2.5 and blood were significantly higher in Guiyu than Haojiang. Remarkably, the children of Guiyu had significantly lower birth weight and length, BMI, and chest circumference when compare to their peers from the reference area (all p value < 0.05). Spearman correlation analyses showed that blood Pb was negatively correlated with height (r = -0.130, p < 0.001), weight (r = -0.169, p < 0.001), BMI (r = -0.100, p < 0.05), head circumference (r = -0.095, p < 0.05), and chest circumference (r = -0.112, p < 0.05). After adjustment for the potential confounders in further linear regression analyses, blood Pb was negatively associated with height (β = -0.066, p < 0.05), weight (β = -0.119, p < 0.001), head circumference (β = -0.123, p < 0.01), and chest circumference (β = -0.104, p < 0.05), respectively. No significant association between blood Cd, Cr, or Mn was found with any of our developmental outcomes. Taken together, lead exposure limits or delays the growth and development of preschool children.

Lead isotope profiling in dairy calves.

PubMed

Buchweitz, John; McClure-Brinton, Kimberly; Zyskowski, Justin; Stensen, Lauren; Lehner, Andreas

2015-03-01

Lead (Pb) is a common cause of heavy metal poisonings in cattle. Sources of Pb on farms include crankcase oil, machinery grease, batteries, plumbing, and paint chips. Consequently, consumption of Pb from these sources may negatively impact animal health and Pb may be inadvertently introduced into the food supply. Therefore, the scope of poisoning incidents must be clearly assessed and sources of intoxication identified and strategies to mitigate exposure evaluated and implemented to prevent future exposures. Stable isotope analysis by inductively-coupled plasma mass spectrometry (ICP-MS) has proven itself of value in forensic investigations. We report on the extension of Pb stable isotope analysis to bovine tissues and profile comparisons with paint chips and soils collected from an affected dairy farm to elucidate the primary source. Pb occurs naturally as four stable isotopes: (204)Pb, (206)Pb, (207)Pb, and (208)Pb. Herein a case is reported to illustrate the use of (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios to link environmental sources of exposure with tissues from a poisoned animal. Chemical Pb profiling provides a valuable tool for field investigative approaches to Pb poisoning in production agriculture and is applicable to subclinical exposures. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Potential role of alpha-synuclein and metallothionein in lead-induced inclusion body formation.

PubMed

Zuo, Peijun; Qu, Wei; Cooper, Ryan N; Goyer, Robert A; Diwan, Bhalchandra A; Waalkes, Michael P

2009-09-01

Lead (Pb) produces aggresome-like inclusion bodies (IBs) in target cells as a toxic response. Our prior work shows metallothionein (MT) is required for this process. We used MT-I/II double knockout (MT-null) and parental wild-type (WT) cell lines to further explore the formation process of Pb-induced IBs. Unlike WT cells, MT-null cells did not form IBs after Pb exposure. Western blot of cytosol showed soluble MT protein in WT cells was lost during Pb exposure as IBs formed. Transfection of MT-I into MT-null cells allowed IBs formation after Pb exposure. Considering Pb-induced IBs may be like disease-related aggresomes, which often contain alpha-synuclein (Scna), we investigated Scna expression in cells capable (WT) and incapable (MT-null) of producing IBs after Pb exposure. Scna protein showed poor basal expression in MT-null cells. Pb exposure increased Scna expression only in WT cells. MT transfection increased Scna transcript to WT levels. In WT or MT-transfected MT-null cells, Pb-induced Scna expression rapidly increased and then decreased over 48 h as Pb-induced IBs were formed. A direct interaction between Scna and MT was confirmed ex vivo by antibody pulldown assay where the proteins coprecipitated with an antibody to MT. Pb exposure caused increased colocalization of MT and Scna proteins with time only in WT cells. In WT mice after chronic Pb exposure Scna was localized in renal cells containing forming IBs, whereas MT-null mice did not form IBs. Thus, Scna could be component of Pb-induced IBs and, with MT, may play a role in IBs formation.

The effects of lead exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells.

PubMed

Yang, Meiyuan; Li, Yaobin; Wang, Ying; Cheng, Nuo; Zhang, Yi; Pang, Shimin; Shen, Qiwei; Zhao, Lijuan; Li, Guilin; Zhu, Gaochun

2018-05-15

Lead (Pb) is an environmental neurotoxic metal. Chronic exposure to Pb causes deficits of learning and memory in children and spatial learning deficits in developing rats. In this study we investigated the effects of Pb exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells. The animals were randomly divided to three groups: control group; low lead exposure group; high lead exposure group; PC12 cells were divided into 3 groups: 0 μM (control group), 1 μM and 100 μM Pb acetate. The results showed that Pb levels in blood and brain of Pb exposed groups were significantly higher than that of the control group (p < 0.05). The expression of HMGB1 and HO-1 were increased in Pb exposed groups than that of the control group (p < 0.05). Moreover, we found that the up-regulation of HO-1 in Pb exposure environment inhibited the expression of HMGB1. Copyright © 2018 Elsevier B.V. All rights reserved.

Cross-species coherence in effects and modes of action in support of causality determinations in the U.S. Environmental Protection Agency's Integrated Science Assessment for Lead.

PubMed

Lassiter, Meredith Gooding; Owens, Elizabeth Oesterling; Patel, Molini M; Kirrane, Ellen; Madden, Meagan; Richmond-Bryant, Jennifer; Hines, Erin Pias; Davis, J Allen; Vinikoor-Imler, Lisa; Dubois, Jean-Jacques

2015-04-01

The peer-reviewed literature on the health and ecological effects of lead (Pb) indicates common effects and underlying modes of action across multiple organisms for several endpoints. Based on such observations, the United States (U.S.) Environmental Protection Agency (EPA) applied a cross-species approach in the 2013 Integrated Science Assessment (ISA) for Lead for evaluating the causality of relationships between Pb exposure and specific endpoints that are shared by humans, laboratory animals, and ecological receptors (i.e., hematological effects, reproductive and developmental effects, and nervous system effects). Other effects of Pb (i.e., cardiovascular, renal, and inflammatory responses) are less commonly assessed in aquatic and terrestrial wildlife limiting the application of cross-species comparisons. Determinations of causality in ISAs are guided by a framework for classifying the weight of evidence across scientific disciplines and across related effects by considering aspects such as biological plausibility and coherence. As illustrated for effects of Pb where evidence across species exists, the integration of coherent effects and common underlying modes of action can serve as a means to substantiate conclusions regarding the causal nature of the health and ecological effects of environmental toxicants. Published by Elsevier Ireland Ltd.

Reducing Pb poisoning in birds and Pb exposure in game meat consumers: the dual benefit of effective Pb shot regulation.

PubMed

Mateo, Rafael; Vallverdú-Coll, Núria; López-Antia, Ana; Taggart, Mark A; Martínez-Haro, Monica; Guitart, Raimon; Ortiz-Santaliestra, Manuel E

2014-02-01

The use of lead (Pb) ammunition in the form of shot pellets has been identified as a Pb exposure risk in wildlife and their human consumers. We explore the hypothesis that Pb shot ban enforcement reduces the risk of avian Pb poisoning as well as Pb exposure in game meat consumers. We assessed compliance with a partial ban on Pb shot commencing in 2003 by examination of 937 waterbirds harvested by hunters between 2007 and 2012 in the Ebro delta (Spain). Prevalence of Pb shot ingestion was determined, as were Pb concentrations in liver and muscle tissue to evaluate the potential for Pb exposure in game meat consumers. Hunted birds with only embedded Pb shot (no steel) declined from 26.9% in 2007-08 to <2% over the following three hunting seasons after ban reinforcement. Pb shot ingestion in mallards decreased from a pre-ban value of 30.2% to 15.5% in the post-ban period. Liver Pb levels were predominantly defined by the presence of ingested shot, whereas muscle levels were defined by the presence of both ingested and embedded shot. Only 2.5% of mallard muscle tissue had Pb levels above European Union regulations for meat (0.1μg/g wet weight) in the 2008-09 season, when Pb shot ingestion prevalence was also at a minimum (5.1%). Effective restrictions in Pb ammunition use have a dual benefit since this reduces Pb exposure for game meat consumers due to embedded ammunition as well as reducing Pb poisoning in waterbirds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Epigenetic marker (LINE-1 promoter) methylation level was associated with occupational lead exposure.

PubMed

Li, Chunping; Yang, Xiaolin; Xu, Ming; Zhang, Jinlong; Sun, Na

2013-05-01

Occupational and environmental exposures to lead (Pb) are a worldwide concern. DNA methylation plays an important role in the development of Pb toxicity. Here, we try to find out the evidence to prove that the methylation of the LINE-1 promoter may be involved in Pb toxicity. To determine whether the methylation level of the LINE-1 is associated with the risk of Pb poisoning, we first constructed a Pb acetate-treated cell model to detect the association between LINE-1 methylation and Pb exposure. A case-control study involving 53 workers from a battery plant and 57 healthy volunteers with matching age and gender distribution was carried out. We employed methylation-specific real-time PCR to determine the relationship between LINE-1 methylation level and Pb exposure. In the cell model, Pb exposure significantly decreased the level of LINE-1 methylation (p = 0.009). Significant difference in methylation frequencies was found between the exposed and control samples (p < 0.001). We also found a decreasing trend of LINE-1 methylation level with increasing blood Pb level (p < 0.001). Therefore, the LINE-1 promoter methylation might contribute to the risk of Pb poisoning and identified a possible epigenetic biomarker for Pb toxicity, especially in individuals occupationally exposed to Pb.

Peripheral Blood Signatures of Lead Exposure

PubMed Central

LaBreche, Heather G.; Meadows, Sarah K.; Nevins, Joseph R.; Chute, John P.

2011-01-01

Background Current evidence indicates that even low-level lead (Pb) exposure can have detrimental effects, especially in children. We tested the hypothesis that Pb exposure alters gene expression patterns in peripheral blood cells and that these changes reflect dose-specific alterations in the activity of particular pathways. Methodology/Principal Finding Using Affymetrix Mouse Genome 430 2.0 arrays, we examined gene expression changes in the peripheral blood of female Balb/c mice following exposure to per os lead acetate trihydrate or plain drinking water for two weeks and after a two-week recovery period. Data sets were RMA-normalized and dose-specific signatures were generated using established methods of supervised classification and binary regression. Pathway activity was analyzed using the ScoreSignatures module from GenePattern. Conclusions/Significance The low-level Pb signature was 93% sensitive and 100% specific in classifying samples a leave-one-out crossvalidation. The high-level Pb signature demonstrated 100% sensitivity and specificity in the leave-one-out crossvalidation. These two signatures exhibited dose-specificity in their ability to predict Pb exposure and had little overlap in terms of constituent genes. The signatures also seemed to reflect current levels of Pb exposure rather than past exposure. Finally, the two doses showed differential activation of cellular pathways. Low-level Pb exposure increased activity of the interferon-gamma pathway, whereas high-level Pb exposure increased activity of the E2F1 pathway. PMID:21829687

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.

Enhanced Nitric Oxide Production during Lead (Pb2+) Exposure Recovers Protein Expression but not Presynaptic Localization of Synaptic Proteins in Developing Hippocampal Neurons

PubMed Central

Neal, April P.; Stansfield, Kirstie H.; Guilarte, Tomás R.

2012-01-01

We have previously reported that lead (Pb2+) exposure results in both presynaptic and postsynaptic changes in developing neurons as a result of inhibition of the N-methyl-D-aspartate receptor (NMDAR). NMDAR inhibition by Pb2+ during synaptogenesis disrupts downstream trans-synaptic signaling of brain-derived neurotrophic factor (BDNF) and exogenous addition of BDNF can recover the effects of Pb2+ on both presynaptic protein expression and presynaptic vesicular release. NMDAR activity can modulate other trans-synaptic signaling pathways, such as nitric oxide (NO) signaling. Thus, it is possible that other trans-synaptic pathways in addition to BDNF signaling may be disrupted by Pb2+ exposure. The current study investigated whether exogenous addition of NO could recover the presynaptic vesicular proteins lost as a result of Pb2+ exposure during synaptogenesis, namely Synaptophysin (Syn) and Synaptobrevin (Syb). We observed that exogenous addition of NO during Pb2+ exposure results in complete recovery of whole-cell Syn levels and partial recovery of Syn and Syb synaptic targeting in Pb2+-exposed neurons. PMID:22265330

Effects of lead on Na+, K+-ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

USGS Publications Warehouse

Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Shea, Damian; Kwak, Thomas J.

2012-01-01

Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28-day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water-only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 mu g/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na+, K+, Cl-, Ca2+) concentrations, and Na+, K+-ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure-dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 mu g/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 mu g/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 mu g/g. The Na+, K+-ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R2 = 0.92; P = 0.013). The Na+, K+-ATPase activity was correlated with reduced hemolymph Na+ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca2+ concentration increased significantly in mussels from the greatest Pb exposure and may be due to remobilization from the shell in an attempt to buffer the hemolymph against Pb uptake and toxicity. We conclude that Na+, K+-ATPase activity in mussels was adversely affected by Pb exposure, however, because the effects on activity were variable at the lower test concentrations, additional research is warranted over this range of exposures. (C) 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.

Lead concentration in plasma as a biomarker of exposure and risk, and modification of toxicity by δ-aminolevulinic acid dehydratase gene polymorphism.

PubMed

Tian, Liting; Zheng, Guang; Sommar, Johan Nilsson; Liang, Yihuai; Lundh, Tomas; Broberg, Karin; Lei, Lijian; Guo, Weijun; Li, Yulan; Tan, Mingguang; Skerfving, Staffan; Jin, Taiyi; Bergdahl, Ingvar A

2013-08-14

Blood lead concentration (B-Pb), the main biomarker of lead exposure and risk, is curvi-linearily related to exposure. We assessed plasma lead (P-Pb) as a marker for both lead exposure and toxic effects. We examined claims that δ-aminolevulinic acid dehydratase genotype (ALAD) can modify lead toxicity. In 290 lead-exposed and 91 unexposed Chinese workers, we determined P-Pb, B-Pb, urinary lead (U-Pb), ALAD polymorphism (rs1800435, ALAD1/2; TaqMan assay), and also toxic effects on heme synthesis (blood zinc protoporphyrin and hemoglobin, urinary δ-aminolevulic acid), on the kidneys (urinary albumin, β2-microglobulin and N-acetyl-β-d-glucosaminidase) and on the peripheral nervous system (sensory and motor conduction velocities). In exposed workers, median P-Pb was 4.10 (range 0.35-27)μg/L, B-Pb 401 (110-950)μg/L, and U-Pb 188 (22-590)μg/g creatinine. P-Pb had a higher ratio between exposed and unexposed workers (median 39, range 18-110) than B-Pb (19, 15-36; p<0.001) and U-Pb (28, 15-36; p<0.001). All three biomarkers were associated with all toxic effects (P-Pb: rS=-0.10 to 0.79; B-Pb: rS=-0.08 to 0.75; all p<0.05). In the exposed workers, B-Pb and U-Pb were significantly higher (p=0.04) in ALAD2 carriers (7% in the exposed population) than in ALAD1 homozygotes. P-Pb values were similar; ALAD1 homozygotes suffered higher kidney toxicity at the same P-Pb. (i) P-Pb has advantages over B-Pb as a biomarker of high Pb exposure, but it was not significantly better as an index of risk of toxicity. (ii) The ALAD genotype modifies toxicokinetics and toxicodynamics. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

An exposure and health risk assessment of lead (Pb) in lipstick.

PubMed

Monnot, Andrew D; Christian, Whitney V; Abramson, Matthew M; Follansbee, Mark H

2015-06-01

Lead (Pb) content in lipstick and other consumer products has become an increasing concern. In 2010, the United States Food and Drug Administration tested 400 lipstick samples and found a maximum Pb concentration of 7.19 ppm. To assess the safety of lipstick in adults that chronically apply lipstick as well as instances where children might incidentally ingest lipstick products, the United States Environmental Protection Agency's (US EPA) Adult Lead Model and Integrated Exposure Uptake Biokinetic Model for Lead in Children were used to determine the blood Pb concentrations of adults and children ingesting varying amounts of lipstick of different Pb concentrations. Modeled blood Pb concentrations were compared with oral ingestion guidelines and to the Centers for Disease Control and the US EPA's actionable blood Pb levels of 5 and 10 µg/dL. Background Pb exposure was the primary contributor to estimated blood Pb levels (BLLs) in children and adults, and Pb exposure from lipstick did not significantly increase estimated BLLs. These results suggest that the safety of consumer products and cosmetics should be assessed not only by the presence and amounts of hazardous contents, but also in conjunction with an assessment of estimated background exposures and comparison to health-based standards. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth

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

Shepherd, Thomas J.; British Geological Survey, Keyworth, Nottingham; Dirks, Wendy

We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and {sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5–8 years, living in NE England. By integrating the isotope datamore » with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2–3 years for molars, first 1–2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2 µg Pb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.126–2.079) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.879–0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM{sub 10}, PM{sub 2.5}) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4 µgPb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.145–2.117) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.898–0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1–2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot study confirms that laser ablation Pb isotope analysis of deciduous teeth, when carried out in conjunction with histological analysis, permits a reconstruction of the timing, duration and source of exposure to Pb during early childhood. With further development, this approach has the potential to study larger cohorts and appraise environments where the levels of exposure to Pb are much higher. - Highlights: • Reconstructing a high resolution chronology of early childhood exposure to lead. • Combined laser ablation lead isotope – histological analysis of children's teeth. • Using dentine to recover information on the intensity, duration and source of lead. • Importance of industrial airborne lead pollution in a post-leaded petrol era.« less

Long-term lead elimination from plasma and whole blood after poisoning.

PubMed

Rentschler, Gerda; Broberg, K; Lundh, T; Skerfving, S

2012-04-01

Blood lead (B-Pb), one of the most used toxicological biomarker all kind, has serious limitations. Thus, the objective is to evaluate whether plasma lead (P-Pb) is more adequate. A long-term follow-up study of five cases of lead poisoning. P-Pb was analysed by inductively coupled plasma mass spectrometry. Kinetics after end of exposure was modelled. P-Pb at severe poisoning was about 20 μg/L; haematological effects at about 5 μg/L. Biological half-time of P-Pb was about 1 month; B-Pb decay was much slower. P-Pb is a valuable biomarker of exposure to and risk, particularly at high exposure.

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.

Associations of cumulative Pb exposure and longitudinal changes in Mini-Mental Status Exam scores, global cognition and domains of cognition: The VA Normative Aging Study.

PubMed

Farooqui, Zishaan; Bakulski, Kelly M; Power, Melinda C; Weisskopf, Marc G; Sparrow, David; Spiro, Avron; Vokonas, Pantel S; Nie, Linda H; Hu, Howard; Park, Sung Kyun

2017-01-01

Lead (Pb) exposure has been associated with poorer cognitive function cross-sectionally in aging adults, however the association between cumulative Pb exposure and longitudinal changes in cognition is little characterized. In a 1993-2007 subcohort of the VA Normative Aging Study (Mini-mental status exam (MMSE) n=741; global cognition summary score n=715), we used linear mixed effects models to test associations between cumulative Pb exposure (patella or tibia bone Pb) and repeated measures of cognition (MMSE, individual cognitive tests, and global cognition summary). Cox proportional hazard modeling assessed the risk of an MMSE score falling below 25. Among men 51-98 at baseline, higher patella Pb concentration (IQR: 21μg/g) was associated with -0.13 lower baseline MMSE (95% CI: -0.25, -0.004) and faster longitudinal MMSE decline (-0.016 units/year, 95% CI: -0.032, -0.0004) over 15 years. Each IQR increase in patella Pb was associated with increased risk of a MMSE score below 25 (HR=1.21, 95% CI: 0.99, 1.49; p=0.07). There were no significant associations between Pb and global cognition (both baseline and longitudinal change). Patella Pb was associated with faster longitudinal decline in Word List Total Recall in the language domain (0.014 units/year, 95% CI: -0.026, -0.001) and Word List Delayed Recall in the memory domain (0.014 units/year, 95% CI: -0.027, -0.002). We found weaker associations with tibia Pb. Cumulative Pb exposure is associated with faster declines in MMSE and Word List Total and Delayed Recall tests. These findings support the hypothesis that Pb exposure accelerates cognitive aging. Copyright © 2016 Elsevier Inc. All rights reserved.

Perinatal Lead Exposure Alters Gut Microbiota Composition and Results in Sex-specific Bodyweight Increases in Adult Mice

PubMed Central

Wu, Jianfeng; Wen, Xiaoquan William; Faulk, Christopher; Boehnke, Kevin; Zhang, Huapeng; Dolinoy, Dana C.; Xi, Chuanwu

2016-01-01

Heavy metal pollution is a principle source of environmental contamination. Epidemiological and animal data suggest that early life lead (Pb) exposure results in critical effects on epigenetic gene regulation and child and adult weight trajectories. Using a mouse model of human-relevant exposure, we investigated the effects of perinatal Pb exposure on gut microbiota in adult mice, and the link between gut microbiota and bodyweight changes. Following Pb exposure during gestation and lactation via maternal drinking water, bodyweight in Avy strain wild-type non-agouti (a/a) offspring was tracked through adulthood. Gut microbiota of adult mice were characterized by deep DNA sequencing of bacterial 16S ribosomal RNA genes. Data analyses were stratified by sex and adjusted for litter effects. A Bayesian variable selection algorithm was used to analyze associations between bacterial operational taxonomic units and offspring adult bodyweight. Perinatal Pb exposure was associated with increased adult bodyweight in male (P < .05) but not in female offspring (P = .24). Cultivable aerobes decreased and anaerobes increased in Pb-exposed offspring (P < .005 and P < .05, respectively). Proportions of the 2 predominant phyla (Bacteroidetes and Firmicutes) shifted inversely with Pb exposure, and whole bacterial compositions were significantly different (analysis of molecular variance, P < .05) by Pb exposure without sex bias. In males, changes in gut microbiota were highly associated with adult bodyweight (P = .028; effect size = 2.59). Thus, perinatal Pb exposure results in altered adult gut microbiota regardless of sex, and these changes are highly correlated with increased bodyweight in males. Adult gut microbiota can be shaped by early exposures and may contribute to disease risks in a sex-specific manner. PMID:26962054

Human health risk assessment of lead pollution in atmospheric deposition in Baoshan District, Shanghai.

PubMed

Chen, Yuanyuan; Wang, Jun; Shi, Guitao; Sun, Xiaojing; Chen, Zhenlou; Xu, Shiyuan

2011-12-01

The lead (Pb) content in atmospheric deposition was determined at 42 sampling sites in Baoshan District of Shanghai, China. Based on exposure and dose-response assessments, the health risk caused by Pb exposure in atmospheric deposition was investigated. The results indicated that Pb was significantly accumulated in atmospheric deposition. The spatial distribution of Pb was mapped by geostatistical analysis, and the results showed that pollution hotspots were present at traffic and industrial zones. Ingestion was the main route of Pb exposure in both adults and children. For children the risk value was above 1, whereas it was below 1 for the adult group. Therefore, children belong to the high-risk group for Pb exposure from atmospheric deposition in the observed area of Shanghai, China.

Modeling personal particle-bound polycyclic aromatic hydrocarbon (pb-pah) exposure in human subjects in Southern California.

PubMed

Wu, Jun; Tjoa, Thomas; Li, Lianfa; Jaimes, Guillermo; Delfino, Ralph J

2012-07-11

Exposure to polycyclic aromatic hydrocarbon (PAH) has been linked to various adverse health outcomes. Personal PAH exposures are usually measured by personal monitoring or biomarkers, which are costly and impractical for a large population. Modeling is a cost-effective alternative to characterize personal PAH exposure although challenges exist because the PAH exposure can be highly variable between locations and individuals in non-occupational settings. In this study we developed models to estimate personal inhalation exposures to particle-bound PAH (PB-PAH) using data from global positioning system (GPS) time-activity tracking data, traffic activity, and questionnaire information. We conducted real-time (1-min interval) personal PB-PAH exposure sampling coupled with GPS tracking in 28 non-smoking women for one to three sessions and one to nine days each session from August 2009 to November 2010 in Los Angeles and Orange Counties, California. Each subject filled out a baseline questionnaire and environmental and behavior questionnaires on their typical activities in the previous three months. A validated model was used to classify major time-activity patterns (indoor, in-vehicle, and other) based on the raw GPS data. Multiple-linear regression and mixed effect models were developed to estimate averaged daily and subject-level PB-PAH exposures. The covariates we examined included day of week and time of day, GPS-based time-activity and GPS speed, traffic- and roadway-related parameters, meteorological variables (i.e. temperature, wind speed, relative humidity), and socio-demographic variables and occupational exposures from the questionnaire. We measured personal PB-PAH exposures for 180 days with more than 6 h of valid data on each day. The adjusted R2 of the model was 0.58 for personal daily exposures, 0.61 for subject-level personal exposures, and 0.75 for subject-level micro-environmental exposures. The amount of time in vehicle (averaging 4.5% of total sampling time) explained 48% of the variance in daily personal PB-PAH exposure and 39% of the variance in subject-level exposure. The other major predictors of PB-PAH exposures included length-weighted traffic count, work-related exposures, and percent of weekday time. We successfully developed regression models to estimate PB-PAH exposures based on GPS-tracking data, traffic data, and simple questionnaire information. Time in vehicle was the most important determinant of personal PB-PAH exposure in this population. We demonstrated the importance of coupling real-time exposure measures with GPS time-activity tracking in personal air pollution exposure assessment.

[Effect of lead and selenium on learning and memory ability in rats].

PubMed

Han, Xiaojie; Hu, Xiaoxia; Wei, Qing; Chen, Yilin; Yu, De'e; Hu, Qiansheng

2013-11-01

To study the effect of lead and (or) selenium on learning and memory ability in rats. SPF Wistar rats, after weaning, were divided into six groups, control group, Pb group (respectively Pb exposed), Se group (respectively Se added), Pb-Se group (added Se after Pb exposure), Se-Pb group (added Se before Pb exposure) and Pb + Se group (Pb and Se exposed simultaneously). After intervention for six weeks in rats, the spatial learning and memory of each group rats were measured by Morris water maze assay. Rats in Pb group had significantly longer latency, less site crossings, less percentage of time and distance spent in the target quadrant, and bigger first bearing compared with control group (P < 0.05). Rats in Pb and Se joint exposure groups had significantly shorter latency, more site crossings, less percentage of time and distance spent in the target quadrant, and smaller first bearing compared with Pb group (P < 0.05). There were no significant differences in the indexes of spatial learning and memory ability between the groups of lead and selenium joint exposure groups (P > 0.05). Lead damaged the ability of learning and memory in rats and organic selenium had protective effects on Pb-induced spatial learning and memory deficits in rats.

Foliar or root exposures to smelter particles: consequences for lead compartmentalization and speciation in plant leaves.

PubMed

Schreck, Eva; Dappe, Vincent; Sarret, Géraldine; Sobanska, Sophie; Nowak, Dorota; Nowak, Jakub; Stefaniak, Elżbieta Anna; Magnin, Valérie; Ranieri, Vincent; Dumat, Camille

2014-04-01

In urban areas with high fallout of airborne particles, metal uptake by plants mainly occurs by foliar pathways and can strongly impact crop quality. However, there is a lack of knowledge on metal localization and speciation in plants after pollution exposure, especially in the case of foliar uptake. In this study, two contrasting crops, lettuce (Lactuca sativa L.) and rye-grass (Lolium perenne L.), were exposed to Pb-rich particles emitted by a Pb-recycling factory via either atmospheric or soil application. Pb accumulation in plant leaves was observed for both ways of exposure. The mechanisms involved in Pb uptake were investigated using a combination of microscopic and spectroscopic techniques (electron microscopy, laser ablation, Raman microspectroscopy, and X-ray absorption spectroscopy). The results show that Pb localization and speciation are strongly influenced by the type of exposure (root or shoot pathway) and the plant species. Foliar exposure is the main pathway of uptake, involving the highest concentrations in plant tissues. Under atmospheric fallouts, Pb-rich particles were strongly adsorbed on the leaf surface of both plant species. In lettuce, stomata contained Pb-rich particles in their apertures, with some deformations of guard cells. In addition to PbO and PbSO4, chemical forms that were also observed in pristine particles, new species were identified: organic compounds (minimum 20%) and hexagonal platy crystals of PbCO3. In rye-grass, the changes in Pb speciation were even more egregious: Pb-cell wall and Pb-organic acid complexes were the major species observed. For root exposure, identified here as a minor pathway of Pb transfer compared to foliar uptake, another secondary species, pyromorphite, was identified in rye-grass leaves. Finally, combining bulk and spatially resolved spectroscopic techniques permitted both the overall speciation and the minor but possibly highly reactive lead species to be determined in order to better assess the health risks involved. Copyright © 2013 Elsevier B.V. All rights reserved.

Enhanced nitric oxide production during lead (Pb²⁺) exposure recovers protein expression but not presynaptic localization of synaptic proteins in developing hippocampal neurons.

PubMed

Neal, April P; Stansfield, Kirstie H; Guilarte, Tomás R

2012-02-23

We have previously reported that lead (Pb(2+)) exposure results in both presynaptic and postsynaptic changes in developing neurons as a result of inhibition of the N-methyl-d-aspartate receptor (NMDAR). NMDAR inhibition by Pb(2+) during synaptogenesis disrupts downstream trans-synaptic signaling of brain-derived neurotrophic factor (BDNF) and exogenous addition of BDNF can recover the effects of Pb(2+) on both presynaptic protein expression and presynaptic vesicular release. NMDAR activity can modulate other trans-synaptic signaling pathways, such as nitric oxide (NO) signaling. Thus, it is possible that other trans-synaptic pathways in addition to BDNF signaling may be disrupted by Pb(2+) exposure. The current study investigated whether exogenous addition of NO could recover the presynaptic vesicular proteins lost as a result of Pb(2+) exposure during synaptogenesis, namely Synaptophysin (Syn) and Synaptobrevin (Syb). We observed that exogenous addition of NO during Pb(2+) exposure results in complete recovery of whole-cell Syn levels and partial recovery of Syn and Syb synaptic targeting in Pb(2+)-exposed neurons. Copyright © 2011 Elsevier B.V. All rights reserved.

Protective Efficacy of Selenite against Lead-Induced Neurotoxicity in Caenorhabditis elegans

PubMed Central

Tseng, I-Ling; Liao, Vivian Hsiu-Chuan

2013-01-01

Background Selenium is an essential micronutrient that has a narrow exposure window between its beneficial and toxic effects. This study investigated the protective potential of selenite (IV) against lead (Pb(II))-induced neurotoxicity in Caenorhabditis elegans. Principal Findings The results showed that Se(IV) (0.01 µM) pretreatment ameliorated the decline of locomotion behaviors (frequencies of body bends, head thrashes, and reversal ) of C. elegans that are damaged by Pb(II) (100 µM) exposure. The intracellular ROS level of C. elegans induced by Pb(II) exposure was significantly lowered by Se(IV) supplementation prior to Pb(II) exposure. Finally, Se(IV) protects AFD sensory neurons from Pb(II)-induced toxicity. Conclusions Our study suggests that Se(IV) has protective activities against Pb(II)-induced neurotoxicity through its antioxidant property. PMID:23638060

Environmental and socioeconomic factors contributing to elevated blood lead levels in children from an industrial area of Upper Silesia.

PubMed

Pelc, Wojciech; Pawlas, Natalia; Dobrakowski, Michał; Kasperczyk, Sławomir

2016-10-01

The present study concentrated on a cross-sectional analysis of recent exposure to lead (Pb) and the socioeconomic factors behind increased Pb exposure in Polish children. Lead is one of the most widespread toxic heavy metals in the industrial region of Upper Silesia (Poland). Elevated blood Pb levels in children continue to be a matter of serious concern. The present study involved 4882 children from the Upper Silesia region, aged from 3 yr to 18 yr, over the calendar years 1999 to 2013. The concentration of Pb in blood was determined in each child. The children's parents were asked to answer survey questions about the child's environmental exposure to Pb as well as the socioeconomic condition of the family. Factors that correspond with increased exposure to Pb included: lower level of education of parents, unemployment, parents' occupational Pb exposure, poor socioeconomic status of the family, smoking at home, living on the ground floor of buildings, consumption of locally grown vegetables and fruits, longer outdoor playing periods in a polluted environment, and male gender. Environmental exposure to Pb is the most important factor behind chronic poisoning of children in Upper Silesia. The most important socioeconomic factor associated with concentrations of Pb in children's blood is a lower level of education of a child's mother and father. Environ Toxicol Chem 2016;35:2597-2603. © 2016 SETAC. © 2016 SETAC.

Associations of cumulative Pb exposure and longitudinal changes in Mini-Mental Status Exam scores, global cognition and domains of cognition: The VA Normative Aging Study

PubMed Central

Farooqui, Zishaan; Bakulski, Kelly M.; Power, Melinda C.; Weisskopf, Marc G.; Sparrow, David; Spiro, Avron; Vokonas, Pantel S.; Nie, Huiling; Hu, Howard; Park, Sung Kyun

2016-01-01

Background Lead (Pb) exposure has been associated with poorer cognitive function cross-sectionally in aging adults, however the association between cumulative Pb exposure and longitudinal changes in cognition is little characterized. Methods In a 1993–2007 subcohort of the VA Normative Aging Study (Mini-mental status exam (MMSE) n=741; global cognition summary score n=715), we used linear mixed effects models to test associations between cumulative Pb exposure (patella or tibia bone Pb) and repeated measures of cognition (MMSE, individual cognitive tests, and global cognition summary). Cox proportional hazard modeling assessed the risk of an MMSE score falling below 25. Results Among men 51–98 at baseline, higher patella Pb concentration (IQR: 21 µg/g) was associated with −0.13 lower baseline MMSE (95% CI: −0.25, −0.004) and faster longitudinal MMSE decline (−0.016 units/year, 95% CI: −0.032, −0.0004) over 15 years. Each IQR increase in patella Pb was associated with increased risk of a MMSE score below 25 (HR=1.21, 95% CI: 0.99, 1.49; p=0.07). There were no significant associations between Pb and global cognition (both baseline and longitudinal change). Patella Pb was associated with faster longitudinal decline in Word List Total Recall in the language domain (0.014 units/year, 95% CI: −0.026, −0.001) and Word List Delayed Recall in the memory domain (0.014 units/year, 95% CI: −0.027, −0.002). We found weaker associations with tibia Pb. Conclusions Cumulative Pb exposure is associated with faster declines in MMSE and Word List Total and Delayed Recall tests. These findings support the hypothesis that Pb exposure accelerates cognitive aging. PMID:27770710

Exposure assessment of lead from food and airborne dusts and biomonitoring in pregnant mothers, their fetus and siblings in Karachi, Pakistan and Shimotsuke, Japan.

PubMed

Kayama, Fujio; Fatmi, Zafar; Ikegami, Akihiko; Mizuno, Atsuko; Ohtsu, Mayumi; Mise, Nathern; Cui, Xiaoyi; Ogawa, Masanori; Sakamoto, Takako; Nakagi, Yoshiko; Yoshida, Takahiko; Sahito, Ambreen; Naeem, Shahla; Ghias, Kulsoom; Zuberi, Hina; Tariq, Kanwal; Kobayashi, Yayoi; Nohara, Keiko

2016-03-01

Exposure assessment of lead (Pb) and Arsenic (As) from food, water, and house dust intake were assessed among pregnant women, their children and fetuses in Pakistan and Japan, as well as their body burden of the metals in their blood. Fifty families which included a pregnant woman, a fetus and the 1-3-year-old siblings were recruited in Karachi and Khairpur in Pakistan, and Shimotsuke and Asahikawa in Japan, respectively. Their dietary exposure to Pb and As was measured in 3-day food duplicates and drinking water by ICP-MP. Pb in house dust and respirable dust was evaluated with an energy dispersive X-ray fluorescence spectrometry. Non-radioactive isotope Pb profiles of blood specimens will be compared with those of the exposure origins, such as food duplicates, respirable house dust, the soils nearby, and gasoline. Judging from the data collected and analyzed so far, contribution from dietary intake is highly correlated to higher body burden of Pb among Pakistani mothers. Additional data analyses will reveal the status of Pb and As body burden in Pakistani mothers, fetuses and their siblings, and causal sources of high body burden is delineated by Pb isotope profile analysis of different sources of Pb exposure.

The bioavailability and adverse impacts of lead and decabromodiphenyl ether on soil microbial activities.

PubMed

Chen, Lei; Zhang, Wei; Zhang, Rong; Lin, Kuangfei; He, Lei; Wu, Liqun

2015-08-01

Lead (Pb) and decabromodiphenyl ether (BDE209) are the main pollutants at electronic waste (e-waste) recycling sites (EWRSs), and their potential toxic effects on soil organisms have received extensive attention. However, the impact on soil microorganisms of joint exposure to the two chemicals remains almost unknown. Therefore, indoor incubation tests were performed to explore the adverse impacts of Pb and BDE209 on soil microbial activities and chemical transformation for the first time. The results have demonstrated that BDE209 was barely degraded in all treated groups, indicating that the presence of Pb hardly affected BDE209 dissipation. The fractions analysis according to Tessier suggested that Pb gradually transformed towards more stable fractions in the slightly alkaline soil, thus reducing the bioavailability of Pb. Additionally, increased Pb doses caused significantly higher bioavailability (p < 0.05), and the same trend was clearly observed after simultaneous exposure to BDE209. Generally, single Pb or BDE209 exposure markedly inhibited (p < 0.05 or 0.01) soil microbial biomass C (C mic), while soil basal respiration (SBR) indicated the opposite response trend (inhibition or stimulation for BDE209 or Pb alone, respectively). Compared to the controls, Pb dramatically (p < 0.01) facilitated soil metabolic quotient (qCO2) during the incubation period. After joint exposure to Pb and BDE209, C mic generally declined with increasing exposure concentration, following certain dose-response relationships. However, SBR and qCO2 were highly significantly stimulated (p < 0.01), and more doses of Pb and BDE209 resulted in higher values. The results of these observations have provided a basic understanding of the potential ecological risk of Pb and BDE209 in soil at EWRSs.

Perinatal Lead Exposure Alters Gut Microbiota Composition and Results in Sex-specific Bodyweight Increases in Adult Mice.

PubMed

Wu, Jianfeng; Wen, Xiaoquan William; Faulk, Christopher; Boehnke, Kevin; Zhang, Huapeng; Dolinoy, Dana C; Xi, Chuanwu

2016-06-01

Heavy metal pollution is a principle source of environmental contamination. Epidemiological and animal data suggest that early life lead (Pb) exposure results in critical effects on epigenetic gene regulation and child and adult weight trajectories. Using a mouse model of human-relevant exposure, we investigated the effects of perinatal Pb exposure on gut microbiota in adult mice, and the link between gut microbiota and bodyweight changes. Following Pb exposure during gestation and lactation via maternal drinking water, bodyweight in A(vy) strain wild-type non-agouti (a/a) offspring was tracked through adulthood. Gut microbiota of adult mice were characterized by deep DNA sequencing of bacterial 16S ribosomal RNA genes. Data analyses were stratified by sex and adjusted for litter effects. A Bayesian variable selection algorithm was used to analyze associations between bacterial operational taxonomic units and offspring adult bodyweight. Perinatal Pb exposure was associated with increased adult bodyweight in male (P < .05) but not in female offspring (P = .24). Cultivable aerobes decreased and anaerobes increased in Pb-exposed offspring (P < .005 and P < .05, respectively). Proportions of the 2 predominant phyla (Bacteroidetes and Firmicutes) shifted inversely with Pb exposure, and whole bacterial compositions were significantly different (analysis of molecular variance, P < .05) by Pb exposure without sex bias. In males, changes in gut microbiota were highly associated with adult bodyweight (P = .028; effect size = 2.59). Thus, perinatal Pb exposure results in altered adult gut microbiota regardless of sex, and these changes are highly correlated with increased bodyweight in males. Adult gut microbiota can be shaped by early exposures and may contribute to disease risks in a sex-specific manner. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Stability study of PbSe semiconductor nanocrystals over concentration, size, atmosphere, and light exposure.

PubMed

Dai, Quanqin; Wang, Yingnan; Zhang, Yu; Li, Xinbi; Li, Ruowang; Zou, Bo; Seo, JaeTae; Wang, Yiding; Liu, Manhong; Yu, William W

2009-10-20

Infrared-emitting PbSe nanocrystals are of increasing interest in both fundamental research and technical application. However, the practical applications are greatly limited by their poor stability. In this work, absorption and photoluminescence spectra of PbSe nanocrystals were utilized to observe the stability of PbSe nanocrystals over several conventional factors, that is, particle concentration, particle size, temperature, light exposure, contacting atmosphere, and storage forms (solution or solid powder). Both absorption and luminescence spectra of PbSe nanocrystals exposed to air showed dependence on particle concentration, size, and light exposure, which caused large and quick blue-shifts in the optical spectra. This air-contacted instability arising from the destructive oxidation and subsequent collision-induced decomposition was kinetically dominated and differed from the traditional thought that smaller particles with lower concentrations shrank fast. The photoluminescence emission intensity of the PbSe nanocrystal solution under ultraviolet (UV) exposure in air increased first and then decreased slowly; without UV irradiation, the emission intensity monotonously decreased over time. However, if stored under nitrogen, no obvious changes in absorption and photoluminescence spectra of the PbSe nanocrystals were observed even under UV exposure or upon being heated up to 100 degrees C.

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.

Expression of immunoregulatory genes and its relationship to lead exposure and lead-mediated oxidative stress in wild ungulates from an abandoned mining area.

PubMed

Rodríguez-Estival, Jaime; de la Lastra, José M Pérez; Ortiz-Santaliestra, Manuel E; Vidal, Dolors; Mateo, Rafael

2013-04-01

Lead (Pb) is a highly toxic metal that can induce oxidative stress and affect the immune system by modifying the expression of immunomodulator-related genes. The aim of the present study was to investigate the association between Pb exposure and the transcriptional profiles of some cytokines, as well as the relationship between Pb exposure and changes in oxidative stress biomarkers observed in the spleen of wild ungulates exposed to mining pollution. Red deer and wild boar from the mining area studied had higher spleen, liver, and bone Pb levels than controls, indicating a chronic exposure to Pb pollution. Such exposure caused a depletion of spleen glutathione levels in both species and disrupted the activity of antioxidant enzymes, suggesting the generation of oxidative stress conditions. Deer from the mining area also showed an induced T-helper (Th )-dependent immune response toward the Th 2 pathway, whereas boar from the mining area showed a cytokine profile suggesting an inclination of the immune response toward the Th 1 pathway. These results indicate that environmental exposure to Pb may alter immune responses in wild ungulates exposed to mining pollution. However, evidence of direct relationships between Pb-mediated oxidative stress and the changes detected in immune responses were not found. Further research is needed to evaluate the immunotoxic potential of Pb pollution, also considering the prevalence of chronic infectious diseases in wildlife in environments affected by mining activities. Copyright © 2013 SETAC.

Environmental and health disparities in residential communities of New Orleans: the need for soil lead intervention to advance primary prevention.

PubMed

Mielke, Howard W; Gonzales, Christopher R; Powell, Eric T; Mielke, Paul W

2013-01-01

Urban environments are the major sites for human habitation and this study evaluates soil lead (Pb) and blood Pb at the community scale of a U.S. city. There is no safe level of Pb exposure for humans and novel primary Pb prevention strategies are requisite to mitigate children's Pb exposure and health disparities observed in major cities. We produced a rich source of environmental and Pb exposure data for metropolitan New Orleans by combining a large soil Pb database (n=5467) with blood Pb databases (n=55,551 pre-Katrina and 7384 post-Katrina) from the Louisiana Childhood Lead Poisoning Prevention Program (LACLPPP). Reanalysis of pre- and post-Hurricane Katrina soil samples indicates relatively unchanged soil Pb. The objective was to evaluate the New Orleans soil Pb and blood Pb database for basic information about conditions that may merit innovative ways to pursue primary Pb exposure prevention. The city was divided into high (median census tract soil≥100 mg/kg) and low Pb areas (median census tract soil<100mg/kg). Soil and blood Pb concentrations within the high and low Pb areas of New Orleans were analyzed by permutation statistical methods. The high Pb areas are toward the interior of the city where median soil Pb was 367, 313, 1228, and 103 mg/kg, respectively for samples collected at busy streets, residential streets, house sides, and open space locations; the low Pb areas are in outlying neighborhoods of the city where median soil Pb was 64, 46, 32, and 28 mg/kg, respectively for busy streets, residential streets, house sides, and open spaces (P-values<10(-16)). Pre-Katrina children's blood Pb prevalence of ≥5 μg/dL was 58.5% and 24.8% for the high and low Pb areas, respectively compared to post-Katrina prevalence of 29.6% and 7.5%, for high and low Pb areas, respectively. Elevated soil Pb permeates interior areas of the city and children living there generally lack Pb safe areas for outdoor play. Soil Pb medians in outlying areas were safer by factors ranging from 3 to 38 depending on specific location. Patterns of Pb deposition from many decades of accumulation have not been transformed by hastily conducted renovations during the seven year interval since Hurricane Katrina. Low Pb soils available outside of cities can remedy soil Pb contamination within city interiors. Mapping soil Pb provides an overview of deposition characteristics and assists with planning and conducting primary Pb exposure prevention. Copyright © 2012 Elsevier Ltd. All rights reserved.

Lead exposure in raptors from Japan and source identification using Pb stable isotope ratios.

PubMed

Ishii, Chihiro; Nakayama, Shouta M M; Ikenaka, Yoshinori; Nakata, Hokuto; Saito, Keisuke; Watanabe, Yukiko; Mizukawa, Hazuki; Tanabe, Shinsuke; Nomiyama, Kei; Hayashi, Terutake; Ishizuka, Mayumi

2017-11-01

Lead (Pb) poisoning is widespread among raptors and water birds. In Japan, fragments of Pb ammunition are still found in endangered eagles although more than 10 years have passed since legislation regarding use of Pb ammunition was introduced. This study was performed to investigate Pb exposure in raptors from various locations in Japan. We measured hepatic and renal Pb concentrations and hepatic Pb isotope ratios of Steller's sea eagles (Haliaeetus pelagicus), white-tailed sea eagles (Haliaeetus albicilla), golden eagles (Aquila chrysaetos), and 13 other species (total 177 individuals) that were found dead, as well as blood samples from three eagles found in a weakened state during 1993-2015 from Hokkaido (northern part), Honshu (the main island), and Shikoku (a southern island) of Japan. In the present study in Hokkaido, one quarter of the sea eagles showed a high Pb concentration, suggesting exposure to abnormally high Pb levels and Pb poisoning. Pb isotope ratios indicated that endangered Steller's sea eagle and white-tailed sea eagle were poisoned by Pb ammunition that was used illegally in Hokkaido. In other areas of Japan, both surveillance and regulations were less extensive than in Hokkaido, but Pb poisoning in raptors was also noted. Therefore, Pb poisoning is still a serious problem in raptors in various areas of Japan due to accidental ingestion of materials containing Pb, especially Pb ammunition. Copyright © 2017. Published by Elsevier Ltd.

Lead Exposure Impairs Hippocampus Related Learning and Memory by Altering Synaptic Plasticity and Morphology During Juvenile Period.

PubMed

Wang, Tao; Guan, Rui-Li; Liu, Ming-Chao; Shen, Xue-Feng; Chen, Jing Yuan; Zhao, Ming-Gao; Luo, Wen-Jing

2016-08-01

Lead (Pb) is an environmental neurotoxic metal. Pb exposure may cause neurobehavioral changes, such as learning and memory impairment, and adolescence violence among children. Previous animal models have largely focused on the effects of Pb exposure during early development (from gestation to lactation period) on neurobehavior. In this study, we exposed Sprague-Dawley rats during the juvenile stage (from juvenile period to adult period). We investigated the synaptic function and structural changes and the relationship of these changes to neurobehavioral deficits in adult rats. Our results showed that juvenile Pb exposure caused fear-conditioned memory impairment and anxiety-like behavior, but locomotion and pain behavior were indistinguishable from the controls. Electrophysiological studies showed that long-term potentiation induction was affected in Pb-exposed rats, and this was probably due to excitatory synaptic transmission impairment in Pb-exposed rats. We found that NMDA and AMPA receptor-mediated current was inhibited, whereas the GABA synaptic transmission was normal in Pb-exposed rats. NR2A and phosphorylated GluR1 expression decreased. Moreover, morphological studies showed that density of dendritic spines declined by about 20 % in the Pb-treated group. The spine showed an immature form in Pb-exposed rats, as indicated by spine size measurements. However, the length and arborization of dendrites were unchanged. Our results suggested that juvenile Pb exposure in rats is associated with alterations in the glutamate receptor, which caused synaptic functional and morphological changes in hippocampal CA1 pyramidal neurons, thereby leading to behavioral changes.

Effects of Zinc and N-Acetylcysteine in Damage Caused by Lead Exposure in Young Rats.

PubMed

Pedroso, Taíse F; Oliveira, Cláudia S; Fonseca, Mariana M; Oliveira, Vitor A; Pereira, Maria Ester

2017-12-01

This study investigated the toxicity of rats exposed to lead acetate (AcPb) during the second phase of brain development (8-12 days postnatal) in hematological and cerebral parameters. Moreover, the preventive effect of zinc chloride (ZnCl 2 ) and N-acetylcysteine (NAC) was investigated. Pups were injected subcutaneously with saline (0.9% NaCl solution), ZnCl 2 (27 mg/kg/day), NAC (5 mg/kg/day) or ZnCl 2 plus NAC for 5 days (3rd-7th postnatal days), and with saline (0.9% NaCl solution) or AcPb (7 mg/kg/day) in the five subsequent days (8th-12th postnatal days). Animals were sacrificed 21 days after the last AcPb exposure. Pups exposed to AcPb presented inhibition of blood porphobilinogen-synthase (PBG-synthase) activity without changes in hemoglobin content. ZnCl 2 pre-exposure partially prevented PBG-synthase inhibition. Regarding neurotoxicity biomarkers, animals exposed to AcPb presented a decrease in cerebrum acetylcholinesterase (AChE) activity and an increase in Pb accumulation in blood and cerebrum. These changes were prevented by pre-treatment with ZnCl 2 , NAC, and ZnCl 2 plus NAC. AcPb exposure caused no alteration in behavioral tasks. In short, results show that AcPb inhibited the activity of two important enzymatic biomarkers up to 21 days after the end of the exposure. Moreover, ZnCl 2 and NAC prevented the alterations induced by AcPb.

Effects of Pb(Ⅱ) exposure on Chlorella protothecoides and Chlorella vulgaris growth, malondialdehyde, and photosynthesis-related gene transcription.

PubMed

Xiong, Bang; Zhang, Wei; Chen, Lin; Lin, Kuang-Fei; Guo, Mei-Jin; Wang, Wei-Liang; Cui, Xin-Hong; Bi, Hua-Song; Wang, Bin

2014-11-01

Greater exposure to Pb(Ⅱ) increases the likelihood of harmful effects in the environment. In this study, the aquatic unicellular alga Chlorella protothecoides (C. protothecoides) and Chlorella vulgaris (C. vulgaris) were chosen to assess the acute and chronic toxicity of Pb(Ⅱ) exposure. Results of the observations show dose-response relationships could be clearly observed between Pb(Ⅱ) concentration and percentage inhibition (PI). Exposure to Pb(Ⅱ) increased malondialdehyde (MDA) content by up to 4.22 times compared with the control, suggesting that there was some oxidative damage. ANOVA analysis shows that Pb(Ⅱ) decreased chlorophyll (chl) content, indicating marked concentration-dependent relationships, and the lowest levels of chl a, chl b, and total-chl were 14.53, 18.80, and 17.95% of the controls, respectively. A real-time PCR assay suggests the changes in transcript abundances of three photosynthetic-related genes. After 120 h exposure Pb(Ⅱ) reduced the transcript abundance of rbcL, psaB, and psbC, and the relative abundances of the three genes of C. protothecoides and C. vulgaris in response to Pb(Ⅱ) were 54.66-98.59, 51.68-95.59, 37.89-95.48, 36.04-94.94, 41.19-91.20, and 58.75-96.80% of those of the controls, respectively. As for 28 d treatments, the three genes displayed similar inhibitory trend. This research provides a basic understanding of Pb(Ⅱ) toxicity to aquatic organisms. Copyright © 2013 Wiley Periodicals, Inc.

Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

USGS Publications Warehouse

McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

2015-01-01

The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting and hunting seasons. Blood Pb concentrations remain elevated in mottled ducks despite Pb shot bans enacted >25 years prior to this study. If Pb levels in mottled ducks becomes a conservation concern, regional monitoring of blood Pb concentrations would be appropriate with a focus upon elucidating potential reasons for the variation among age and sex groups. Finally, identifying potentially available sources of environmental Pb may be key to minimizing this apparently persistent threat to mottled ducks on the upper Texas coast.

Toxic effects on bioaccumulation and hematological parameters of juvenile rockfish Sebastes schlegelii exposed to dietary lead (Pb) and ascorbic acid.

PubMed

Kim, Jun-Hwan; Kang, Ju-Chan

2017-06-01

Juvenile rockfish, Sebastes schlegelii (mean length 11.3 ± 1.2 cm, and mean weight 32.5 ± 4.1 g) were exposed for four weeks to dietary lead (Pb 2+ ) at 0, 120, and 240 mg/L and ascorbic acid (AsA) at 100, 200, and 400 mg/L. The exposure concentrations and duration of significant Pb-induced accumulations in specific tissues of S. schlegelii were assessed. High levels of ascorbic acid significantly attenuated accumulations following exposure to dietary Pb. Dietary Pb exposure caused a significant increase in blood Pb concentrations, whereas red blood cell (RBC) count, hematocrit, and hemoglobin were significantly decreased. Notable changes were also observed in plasma calcium, magnesium, glucose, cholesterol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvate transaminase (GPT). The growth performance of S. schlegelii was significantly decreased. High doses AsA supplemention were effective in attenuating the changes brought about by dietary Pb exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toxicity assessment of Chlorella vulgaris and Chlorella protothecoides following exposure to Pb(II).

PubMed

Zhang, Wei; Xiong, Bang; Chen, Lin; Lin, Kuangfei; Cui, Xinhong; Bi, Huasong; Guo, Meijin; Wang, Weiliang

2013-07-01

The short- and long-term toxic effects of Pb(II) exposure on Chlorella vulgaris (C. vulgaris) and Chlorella protothecoides (C. protothecoides) were not well understood. The lab study was performed to observe the Pb(II) exposure induced changes. Results of the observations show: (1) higher level of Pb(II) (50 or 80mgL(-1)) could significantly inhibit the growth and chlorophyll a synthesis of both algae in almost all the treatments and dose-response relationships could be clearly observed, (2) the range of EC50 values (24-120h, 67.73-172.45mgL(-1)) indicated that Pb(II) had a relatively limited short-term toxicity to the two algae, while long-term tests (7-28d, 50.41-63.91mgL(-1)) displayed higher toxicity and (3) SOD and CAT activities of both algae after exposed to medium level of Pb(II) were significantly promoted, and their response might be more susceptible in short-term exposure. This research provides a basic understanding of Pb(II) toxicity to aquatic organisms. Copyright © 2013 Elsevier B.V. All rights reserved.

Lead Neurotoxicity on Human Neuroblastoma Cell Line SH-SY5Y is Mediated via Transcription Factor EGR1/Zif268 Induced Disrupted in Scherophernia-1 Activation.

PubMed

You, Yuanyuan; Peng, Bo; Ben, Songbin; Hou, Weijian; Sun, Liguang; Jiang, Wei

2018-07-01

Lead (Pb 2+ ) is a well-known type of neurotoxin and chronic exposure to Pb 2+ induces cognition dysfunction. In this work, the potential role of early growth response gene 1 (EGR1) in the linkage of Pb 2+ exposure and disrupted in scherophernia-1 (DISC1) activity was investigated. Human neuroblastoma cell line SH-SY5Y was subjected to different concentrations of lead acetate (PbAc) to determine the effect of Pb 2+ exposure on the cell viability, apoptosis, and activity of EGR1 and DISC1. Then the expression of EGR1 in SH-SY5Y cells was knocked down with specific siRNA to assess the function of EGR1 in Pb 2+ induced activation of DISC1. The interaction between EGR1 and DISC1 was further validated with dual luciferase assay, Supershift electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP)-PCR. Administration of PbAc decreased cell viability and induced apoptosis in SH-SY5Y cells in a dose-dependent manner. Additionally, exposure to PbAc also up-regulated expression of EGR1 and DISC1 at all concentrations. Knockdown of EGR1 blocked the effect of PbAc on SH-SY5Y cells, indicating the central role of EGR1 in the function of Pb 2+ on activity of DISC1. Based on the results of dual luciferase assay, Supershift EMSA, and ChIP-PCR, EGR1 mediated the effect of Pb 2+ on DISC1 by directly bound to the promoter region of DISC1 gene. The current study elaborated the mechanism involved in the effect of Pb 2+ exposure on expression of DISC1 for the first time: EGR1 activated by Pb 2+ substitution of zinc triggered the transcription of DISC1 gene by directly binding to its promoter.

Estimated lead (Pb) exposures for a population of urban community gardeners.

PubMed

Spliethoff, Henry M; Mitchell, Rebecca G; Shayler, Hannah; Marquez-Bravo, Lydia G; Russell-Anelli, Jonathan; Ferenz, Gretchen; McBride, Murray

2016-08-01

Urban community gardens provide affordable, locally grown, healthy foods and many other benefits. However, urban garden soils can contain lead (Pb) that may pose risks to human health. To help evaluate these risks, we measured Pb concentrations in soil, vegetables, and chicken eggs from New York City community gardens, and we asked gardeners about vegetable consumption and time spent in the garden. We then estimated Pb intakes deterministically and probabilistically for adult gardeners, children who spend time in the garden, and adult (non-gardener) household members. Most central tendency Pb intakes were below provisional total tolerable intake (PTTI) levels. High contact intakes generally exceeded PTTIs. Probabilistic estimates showed approximately 40 % of children and 10 % of gardeners exceeding PTTIs. Children's exposure came primarily from dust ingestion and exposure to higher Pb soil between beds. Gardeners' Pb intakes were comparable to children's (in µg/day) but were dominated by vegetable consumption. Adult household members ate less garden-grown produce than gardeners and had the lowest Pb intakes. Our results suggest that healthy gardening practices to reduce Pb exposure in urban community gardens should focus on encouraging cultivation of lower Pb vegetables (i.e., fruits) for adult gardeners and on covering higher Pb non-bed soils accessible to young children. However, the common practice of replacement of root-zone bed soil with clean soil (e.g., in raised beds) has many benefits and should also continue to be encouraged.

Estimated lead (Pb) exposures for a population of urban community gardeners

PubMed Central

Spliethoff, Henry M.; Mitchell, Rebecca G.; Shayler, Hannah; Marquez-Bravo, Lydia G.; Russell-Anelli, Jonathan; Ferenz, Gretchen; McBride, Murray

2016-01-01

Urban community gardens provide affordable, locally grown, healthy foods and many other benefits. However, urban garden soils can contain lead (Pb) that may pose risks to human health. To help evaluate these risks, we measured Pb concentrations in soil, vegetables, and chicken eggs from New York City community gardens, and we asked gardeners about vegetable consumption and time spent in the garden. We then estimated Pb intakes deterministically and probabilistically for adult gardeners, children who spend time in the garden, and adult (non-gardener) household members. Most central-tendency Pb intakes were below provisional total tolerable intake (PTTI) levels. High-contact intakes generally exceeded PTTIs. Probabilistic estimates showed approximately 40% of children and 10% of gardeners exceeding PTTIs. Children’s exposure came primarily from dust ingestion and exposure to higher-Pb soil between beds. Gardeners’ Pb intakes were comparable to children’s (in µg/d) but were dominated by vegetable consumption. Adult household members ate less garden-grown produce than gardeners and had the lowest Pb intakes. Our results suggest that healthy gardening practices to reduce Pb exposure in urban community gardens should focus on encouraging cultivation of lower-Pb vegetables (i.e., fruits) for adult gardeners and on covering higher-Pb non-bed soils accessible to young children. However, the common practice of replacement of root-zone bed soil with clean soil (e.g., in raised beds) has many benefits and should also continue to be encouraged. PMID:26753554

Metallothionein-Like Proteins and Energy Reserve Levels after Ni and Pb Exposure in the Pacific White Prawn Penaeus vannamei

PubMed Central

Nunez-Nogueira, Gabriel; Mouneyrac, Catherine; Muntz, Alice; Fernandez-Bringas, Laura

2010-01-01

This study analyzed the changes in metallothionein-like proteins (MTLPs) and Energy Reserves (ERs) in hepatopancreas and abdominal muscle of the white prawn Penaeus vannamei. Realistic metal concentration exposure for 10 days to Ni and Pb in solution revealed that juvenile prawns partially induce MTLP in hepatopancreas after Pb exposure. Ni was distributed equally between soluble and insoluble fractions, while Pb was present only in the insoluble fraction, suggesting different detoxification strategy. No changes in lipids and glycogen concentration were detected under these experimental conditions in both tissues analyzed. MTLP could not be considered as a suitable indicator for lead exposure in hepatopancreas. PMID:20862200

Lead and Arsenic Accumulation and Its Effects on Plasma Cortisol Levels in Oreochromis sp.

PubMed

Thang, Nguyen Quoc; Huy, Bui The; Van Tan, Le; Phuong, Nguyen Thi Kim

2017-08-01

The accumulation, elimination and effect of heavy metals on plasma cortisol levels in Oreochromis sp. were studied in the exposure and recovery phases. In the exposure phase, the mean rate of accumulation in the tissues was in the order gill > liver > muscle for Pb exposure and muscle > liver > gill for As exposure. In the recovery phase, the order of elimination in the tissues was gill > liver > muscle for Pb and liver > gill > muscle for As. The amount of cortisol secreted by the Oreochromis sp. after Pb or As treatment was lower compared to Oreochromis sp. in the control group during the exposure phase. In the recovery phase, plasma cortisol levels in Oreochromis sp. increased in all Pb treatment groups while it continuously decreased in all As treatment groups. A fish affected by As has obvious difficulty recovering from the stress response. It was concluded that exposure to the tested concentrations of Pb and As over 20 days could be a potent endocrine disruptor, which may lead to adverse impacts on the health of the Oreochromis sp.

Evaluation of Pharmacokinetic Models for the Disposition of Lead (Pb) in Humans, in Support of Application to Occupational Exposure Limit Derivation

DTIC Science & Technology

2015-11-09

as biokinetic or physiologically-based pharmacokinetic (PBPK) models, can readily incorporate multiple routes of exposure (e.g., baseline dietary ...1998) and in the code provided as a supplement to O’Flaherty (2000), as noted above. An aspect of the O’Flaherty model that contrasts to the... dietary Pb; a stable Pb isotope was substituted for some of the dietary Pb for limited periods. Tracer Pb concentrations were measured in blood

The influence of declining air lead levels on blood lead-air lead slope factors in children.

PubMed

Richmond-Bryant, Jennifer; Meng, Qingyu; Davis, Allen; Cohen, Jonathan; Lu, Shou-En; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa C; Kotchmar, Dennis; Hines, Erin P; Ross, Mary

2014-07-01

It is difficult to discern the proportion of blood lead (PbB) attributable to ambient air lead (PbA), given the multitude of lead (Pb) sources and pathways of exposure. The PbB-PbA relationship has previously been evaluated across populations. This relationship was a central consideration in the 2008 review of the Pb national ambient air quality standards. The objectives of this study were to evaluate the relationship between PbB and PbA concentrations among children nationwide for recent years and to compare the relationship with those obtained from other studies in the literature. We merged participant-level data for PbB from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 9908 (1999-2008) with PbA data from the U.S. Environmental Protection Agency. We applied mixed-effects models, and we computed slope factor, d[PbB]/d[PbA] or the change in PbB per unit change in PbA, from the model results to assess the relationship between PbB and PbA. Comparing the NHANES regression results with those from the literature shows that slope factor increased with decreasing PbA among children 0-11 years of age. These findings suggest that a larger relative public health benefit may be derived among children from decreases in PbA at low PbA exposures. Simultaneous declines in Pb from other sources, changes in PbA sampling uncertainties over time largely related to changes in the size distribution of Pb-bearing particulate matter, and limitations regarding sampling size and exposure error may contribute to the variability in slope factor observed across peer-reviewed studies.

Childhood Exposure to Manganese and Postural Instability in Children living near a Ferromanganese Refinery in Southeastern Ohio

PubMed Central

Rugless, Fedoria; Bhattacharya, Amit; Succop, Paul; Dietrich, Kim N.; Cox, Cyndy; Alden, Jody; Kuhnell, Pierce; Barnas, Mary; Wright, Robert; Parsons, Patrick J.; Praamsma, Meredith L.; Palmer, Christopher D.; Beidler, Caroline; Wittberg, Richard; Haynes, Erin N.

2014-01-01

Airborne manganese (Mn) exposure can result in neurotoxicity and postural instability in occupationally exposed workers, yet few studies have explored the association ambient exposure to Mn in children and postural stability. The goal of this study was to determine the association between Mn and lead (Pb) exposure, as measured by blood Pb, blood and hair Mn and time weighted distance (TWD) from a ferromanganese refinery, and postural stability in children. A subset of children ages 7–9 years enrolled in the Marietta Community Actively Researching Exposure Study (CARES) were invited to participate. Postural balance was conducted on 55 children residing in Marietta, Ohio and the surrounding area. Samples of blood were collected and analyzed for Mn and Pb, and samples of hair were analyzed for Mn. Neuromotor performance was assessed using postural balance testing with a computer force platform system. Pearson correlations were calculated to identify key covariates. Associations between postural balance testing conditions and Mn and Pb exposure were estimated with linear regression analyses adjusting for gender, age, parent IQ, parent age. Mean blood Mn was 10 μg/L (SEM=0.36), mean blood Pb was 0.85 μg/dL (SEM=0.05), and mean hair Mn was 0.76 μg/g (SEM=0.16). Mean residential distance from the refinery was 11.5 km (SEM=0.46). All three measures of Mn exposure were significantly associated with poor postural balance. In addition, low-level blood Pb was also negatively associated with balance outcomes. We conclude that Mn exposure and low-level blood Pb are significantly associated with poor postural balance. PMID:24370548

Lead Toxicity to the Performance, Viability, And Community Composition of Activated Sludge Microorganisms

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

Yuan, L; Zhi, W; Liu, YS

Lead (Pb) is a prominent toxic metal in natural and engineered systems. Current knowledge on Pb toxicity to the activated sludge has been limited to short-term (<= 24 h) toxicity. The effect of extended Pb exposure on process performance, bacterial viability, and community compositions remains unknown. We quantified the 24-h and 7-day Pb toxicity to chemical oxygen demand (COD) and NH3-N removal, bacterial viability, and community compositions using lab-scale experiments. Our results showed that 7-day toxicity was significantly higher than the short-term 24-h toxicity. Ammonia-oxidizing bacteria were more susceptible than the heterotrophs to Pb toxicity. The specific oxygen uptake ratemore » responded quickly to Pb addition and could serve as a rapid indicator for detecting Pb pollutions. Microbial viability decreased linearly with the amount of added Pb at extended exposure. The bacterial community diversity was markedly reduced with elevated Pb concentrations. Surface analysis suggested that the adsorbed form of Pb could have contributed to its toxicity along with the dissolved form. Our study provides for the first time a systematic investigation of the effect of extended exposure of Pb on the performance and microbiology of aerobic treatment processes, and it indicates that long-term Pb toxicity has been underappreciated by previous studies.« less

Evaluating the All-Ages Lead Model Using SiteSpecific Data ...

EPA Pesticide Factsheets

Lead (Pb) exposure continues to be a problem in the United States. Even after years of progress in reducing environmental levels, CDC estimates at least 500,000 U.S. children ages 1-5 years have blood Pb levels (BLL) above the CDC reference level of 5 µg/dL. Childhood Pb exposure is associated with neurological consequences and public health professionals continue to work to reduce Pb exposures. To better understand the relationship between exposure and BLL, the USEPA has developed a beta version of the All-Ages Lead Model (AALM). Compared to the Integrated Exposure Uptake Biokinetics (IEUBK) Model for lead in children, the AALM provides greater flexibility to describe Pb exposures (acute or chronic, constant or intermittent) for any age. At this time, the AALM has the capability to predict exposure in each of the following media: dust/soil, water, air, food, and other. As part of an interagency test group, we evaluated the ability of the AALM beta v4.2 (Leggett version) to predict BLLs for children that were exposed to Pb in their environment near the John T. Lewis and Bros Lead Smelter Superfund site. The model predicted that fourteen children met our inclusion criteria that spent less than 20 hours a week away from the home (e.g., no daycare or school) and had paired BLL and environmental sampling data (i.e., Pb in soil, window sill dust, front door dust, floor dust, and drinking water). The model can predict average BLLs, but it remains difficult to predic

Inhibition of ATPase activity in rat synaptic plasma membranes by simultaneous exposure to metals.

PubMed

Carfagna, M A; Ponsler, G D; Muhoberac, B B

1996-03-08

Inhibition of Na+/K+-ATPase and Mg2+-ATPase activities by in vitro exposure to Cd2+, Pb2+ and Mn2+ was investigated in rat brain synaptic plasma membranes (SPMs). Cd2+ and Pb2+ produced a larger maximal inhibition of Na+/K+-ATPase than of Mg2+-ATPase activity. Metal concentrations causing 50% inhibition of Na+/K+-ATPase activity (IC50 values) were Cd2+ (0.6 microM) < Pb2+ (2.1 microM) < Mn2+ (approximately 3 mM), and the former two metals were substantially more potent in inhibiting SPM versus synaptosomal Na+/K+-ATPase. Dixon plots of SPM data indicated that equilibrium binding of metals occurs at sites causing enzyme inhibition. In addition, IC50 values for SPM K+-dependent p-nitrophenylphosphatase inhibition followed the same order and were Cd2+ (0.4 microM) < Pb2+ (1.2 microM) < Mn2+ (300 microM). Simultaneous exposure to the combinations Cd2+/Mn2+ or Pb2+/Mn2+ inhibited SPM Na+/K+-ATPase activity synergistically (i.e., greater than the sum of the metal-induced inhibitions assayed separately), while Cd2+/Pb2+ caused additive inhibition. Simultaneous exposure to Cd2+/Pb2+ antagonistically inhibited Mg2+-ATPase activity while Cd2+/Mn2+ or Pb2+/Mn2+ additively inhibited Mg2+-ATPase activity at low Mn2+ concentrations, but inhibited antagonistically at higher concentrations. The similar IC50 values for Cd2+ and Pb2+ versus Mn2+ inhibition of Na+/K+-ATPase and the pattern of inhibition/activation upon exposure to two metals simultaneously support similar modes of interaction of Cd2+ and Pb2+ with this enzyme, in agreement with their chemical reactivities.

[Blood lead levels in children from a ceramic center with respect to residence and parental occupation].

PubMed

Ferri, F; Candela, S; Bedeschi, E; Picciati, A M; Davoli, V; Rinaldi, L; Riccò, D

1998-01-01

In a survey carried out in 1981, Pb exposure of children living in two geographical areas of the district of Scandiano and attending the first year of primary school was studied. The two areas were different concerning both traffic and the presence of ceramic tile industries, thus suggesting a different exposure of children. The survey demonstrated blood lead levels (PbB) markedly higher than 10 micrograms/100 ml, a value recently identified by the Centers for Disease Control (CDC, Atlanta, USA) as the limit beyond which children's learning capacity may be damaged. It was evident that both the occupational exposure of parents and, to a lower extent, the residence in zones with higher levels of pollution influenced PbB levels. During the last ten years significant improvements have led to the reduction of atmospheric emissions and of occupational exposure of ceramic workers. A new survey has been carried out in 1995. We examined 147 children attending the first year of primary school, and living in two zones for which a different level of Pb exposure could be assumed. In both zones, a clear reduction of PbB was observed in comparison with data obtained in 1981. Mean and standard deviation for PbB in the two groups were 4.1 +/- 1.71 and 4.5 +/- 2.04 micrograms/100 ml, with median values of 3.7 and 4.0 micrograms/100 ml, respectively. Only two cases (1.4%) exceeded the limit values proposed by CDC. Although the mean PbB were much lower than those observed in 1981, higher PbB were found in children whose parents were occupationally exposed to Pb. Maternal exposure seems to be particularly important in determining PbB in children. In comparison with data from the international literature, our results are very close to those obtained for children living in Scandinavian countries, in Germany or in France and rather different from those obtained by other authors in Italy.

Relationships among DNA hypomethylation, Cd, and Pb exposure and risk of cigarette smoking-related urothelial carcinoma

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

Chung, Chi-Jung

Cigarette smoking and environmental exposure to heavy metals are important global health issues, especially for urothelial carcinoma (UC). However, the effects of cadmium and lead exposure, as well as the levels of DNA hypomethylation, on UC risk are limited. We evaluated the possible exposure sources of Cd and Pb and the relationship among DNA hypomethylation, urinary Cd and Pb levels, and UC risk. We recruited 209 patients with UC and 417 control patients for a hospital-based case–control study between June 2011 and August 2014. We collected environmental exposure-related information with questionnaires. Blood and urine samples were analyzed to measure themore » Cd and Pb exposure and 5-methyl-2′-deoxycytidine levels as a proxy for DNA methylation. Multivariate logistic regression and 95% confidence intervals were applied to estimate the risk for UC. Study participants with high Cd and Pb exposure in blood or urine had significantly increased risk of UC, especially among the smokers. After adjusting for age and gender, the possible connections of individual cumulative cigarette smoking or herb medicine exposure with the increased levels of Cd and Pb were observed in the controls. Participants with 8.66%–12.39% of DNA hypomethylation had significantly increased risk of UC compared with those with ≥ 12.39% of DNA hypomethylation. Environmental factors including cigarette smoking and herb medicine may contribute to the internal dose of heavy metals levels. Repeat measurements of heavy metals with different study design, detailed dietary information, and types of herb medicine should be recommended for exploring UC carcinogenesis in future studies. - Highlights: • Smoking and herb medicine ingestion is associated with increased urinary Cd and Pb levels. • Urinary levels of Cd and Pb are associated with increased risk of UC. • UC carcinogenesis might have partially resulted from DNA hypomethylation.« less

Standard Operating Procedure for the Turbidimetric Determination of Lead in Paint Extracts

EPA Science Inventory

Exposure to lead (Pb) may adversely impact children's brains, nervous systems and many organs. An estimated 310,000 US children ages 1 to 5 have elevated blood leads. In the United States, the major exposure pathway for children to Pb is from deteriorated Pb-based paint (LBP), ...

Dyslipdemia induced by chronic low dose co-exposure to lead, cadmium and manganese in rats: the role of oxidative stress.

PubMed

Oladipo, Olusola Olalekan; Ayo, Joseph Olusegun; Ambali, Suleiman Folorunsho; Mohammed, Bisalla; Aluwong, Tanang

2017-07-01

Lead (Pb), cadmium (Cd) and manganese (Mn) have many potential adverse health effects in vitro and in animal models of clinical toxicity. The current study investigated the dyslipidaemic and oxidative stress effects of chronic low-dose oral exposure to Pb, Cd and Mn and the combination (Pb+Cd+Mn) in rats for 15 weeks. Chronic exposure to the metals did not significantly (P>0.05) alter serum lipid profiles. However, the atherogenic index decreased by 32.2% in the Pb+Cd+Mn group, relative to the control. The triglyceride/high-density lipoprotein cholesterol ratio decreased by 39.4% in the Pb+Cd+Mn group, relative to the control, and elevated by 81.8, 94.8 and 20.8%, relative to the Pb, Cd and Mn groups, respectively. While the serum concentrations of malondialdehyde significantly increased in the Mn and Pb+Cd+Mn groups, that of glutathione peroxidase-1 decreased in the Pb+Cd+Mn group, and metallothionein-1 and zinc concentrations markedly decreased in all the metal treatment groups. The results suggest that long-term exposure of rats to Pb+Cd+Mn may result in hypolipidaemia, mediated via oxidative stress and metal interactions. Individuals who are constantly exposed to environmentally relevant levels of the metals may be at risk of hypolipidaemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Baseline blood Pb levels of black-necked stilts on the upper Texas coast

USGS Publications Warehouse

Riecke, Thomas V.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.

2015-01-01

There are no known biological requirements for lead (Pb), and elevated Pb levels in birds can cause a variety of sub-lethal effects and mortality. Historic and current levels of Pb in mottled ducks (Anas fulvigula) suggest that environmental sources of Pb remain available on the upper Texas coast. Because of potential risks of Pb exposure among coexisting marsh birds, black-necked stilt (Himantopus mexicanus) blood Pb concentrations were measured during the breeding season. Almost 80 % (n = 120) of 152 sampled stilts exceeded the background threshold (>20 μg/dL) for Pb exposure. However, blood Pb concentrations did not vary by age or gender, and toxic or potentially lethal concentrations were rare (<5 %). Consistent, low-level blood Pb concentrations of black-necked stilts in this study suggest the presence of readily bioavailable sources of Pb, although potential impacts on local stilt populations remain unclear.

Relationship between oxidative stress, pathology, and behavioral signs of lead poisoning in mallards

USGS Publications Warehouse

Mateo, R.; Beyer, W.N.; Spann, J.W.; Hoffman, D.J.; Ramis, A.

2003-01-01

Some of the adverse effects of lead (Pb) may be associated with oxidative damage of lipids, proteins or DNA. In a previous study a linkage was observed between the susceptibilities of waterfowl species to Pb poisoning with oxidative stress. To investigate this relationship among the individuals of a single species, four groups of 12 mallards were fed for three weeks diets containing high or low levels of vitamin E (20 or 220 UI/kg) and high or low levels of Pb (0 or 2 g/kg). During the first week of Pb exposure, mallards developed hemolytic anemia, and during the second week, signs of neurological impairment. Histological findings in the Pb exposed mallards were hemosiderosis, demyelinization of sciatic and brachial nerves, and tumefaction of renal tubular epithelium with the presence of intranuclear inclusion bodies. Lipid peroxidation increased with Pb exposure in blood, liver, bile and brain, but decreased in nerves. Glutathione (GSH) increased with Pb exposure in liver and bile, and its oxidized/reduced ratio only increased in bile. Pb exposure inhibited GSH peroxidase activity (GPX) in plasma, liver and brain, and decreased protein thiols (PSH) in blood and liver. Vitamin E significantly prevented lipid peroxidation in nerves, but did not alleviate any sign of Pb poisoning. Pb-induced pathological changes associated with hepatic and nervous functions were significantly correlated with lower GPX activity and PSH concentrations in these tissues rather than lipid peroxidation. Data suggest that inhibition of antioxidant enzymes and interaction with sulfhydryl groups of proteins may play a more important role in Pb poisoning of waterfowl than lipid peroxidation.

Increased β-amyloid deposition in Tg-SWDI transgenic mouse brain following in vivo lead exposure.

PubMed

Gu, Huiying; Robison, Gregory; Hong, Lan; Barrea, Raul; Wei, Xing; Farlow, Martin R; Pushkar, Yulia N; Du, Yansheng; Zheng, Wei

2012-09-03

Previous studies in humans and animals have suggested a possible association between lead (Pb) exposure and the etiology of Alzheimer's disease (AD). Animals acutely exposed to Pb display an over-expressed amyloid precursor protein (APP) and the ensuing accumulation of beta-amyloid (Aβ) in brain extracellular spaces. This study was designed to examine whether in vivo Pb exposure increased brain concentrations of Aβ, resulting in amyloid plaque deposition in brain tissues. Human Tg-SWDI APP transgenic mice, which genetically over-express amyloid plaques at age of 2-3 months, received oral gavages of 50mg/kg Pb acetate once daily for 6 weeks; a control group of the same mouse strain received the same molar concentration of Na acetate. ELISA results revealed a significant increase of Aβ in the CSF, brain cortex and hippocampus. Immunohistochemistry displayed a detectable increase of amyloid plaques in brains of Pb-exposed animals. Neurobehavioral test using Morris water maze showed an impaired spatial learning ability in Pb-treated mice, but not in C57BL/6 wild type mice with the same age. In vitro studies further uncovered that Pb facilitated Aβ fibril formation. Moreover, the synchrotron X-ray fluorescent studies demonstrated a high level of Pb present in amyloid plaques in mice exposed to Pb in vivo. Taken together, these data indicate that Pb exposure with ensuing elevated Aβ level in mouse brains appears to be associated with the amyloid plaques formation. Pb apparently facilitates Aβ fibril formation and participates in deposition of amyloid plaques. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Microarray-based analysis of gene expression in lycopersicon esculentum seedling roots in response to cadmium, chromium, mercury, and lead.

PubMed

Hou, Jing; Liu, Xinhui; Wang, Juan; Zhao, Shengnan; Cui, Baoshan

2015-02-03

The effects of heavy metals in agricultural soils have received special attention due to their potential for accumulation in crops, which can affect species at all trophic levels. Therefore, there is a critical need for reliable bioassays for assessing risk levels due to heavy metals in agricultural soil. In the present study, we used microarrays to investigate changes in gene expression of Lycopersicon esculentum in response to Cd-, Cr-, Hg-, or Pb-spiked soil. Exposure to (1)/10 median lethal concentrations (LC50) of Cd, Cr, Hg, or Pb for 7 days resulted in expression changes in 29 Cd-specific, 58 Cr-specific, 192 Hg-specific and 864 Pb-specific genes as determined by microarray analysis, whereas conventional morphological and physiological bioassays did not reveal any toxicant stresses. Hierarchical clustering analysis showed that the characteristic gene expression profiles induced by Cd, Cr, Hg, and Pb were distinct from not only the control but also one another. Furthermore, a total of three genes related to "ion transport" for Cd, 14 genes related to "external encapsulating structure organization", "reproductive developmental process", "lipid metabolic process" and "response to stimulus" for Cr, 11 genes related to "cellular metabolic process" and "cellular response to stimulus" for Hg, 78 genes related to 20 biological processes (e.g., DNA metabolic process, monosaccharide catabolic process, cell division) for Pb were identified and selected as their potential biomarkers. These findings demonstrated that microarray-based analysis of Lycopersicon esculentum was a sensitive tool for the early detection of potential toxicity of heavy metals in agricultural soil, as well as an effective tool for identifying the heavy metal-specific genes, which should be useful for assessing risk levels due to heavy metals in agricultural soil.

Preliminary study of propyl bromide exposure among New Jersey dry cleaners as a result of a pending ban on perchloroethylene.

PubMed

Blando, James D; Schill, Donald P; De La Cruz, Mary Pauline; Zhang, Lin; Zhang, Junfeng

2010-09-01

Many states are considering, and some states have actively pursued, banning the use of perchloroethylene (PERC) in dry cleaning establishments. Proposed legislation has led many dry cleaners to consider the use of products that contain greater than 90% n-propyl bromide (n-PB; also called 1-bromopropane or 1-BP). Very little information is known about toxicity and exposure to n-PB. Some n-PB-containing products are marketed as nonhazardous and "green" or "organic." This has resulted in some users perceiving the solvent as nontoxic and has resulted in at least one significant poisoning incident in New Jersey. In addition, many dry cleaning operators may not realize that the machine components and settings must be changed when converting from PERC to n-PB containing products. Not performing these modifications may result in overheating and significant leaks in the dry cleaning equipment. A preliminary investigation was conducted of the potential exposures to n-PB and isopropyl bromide (iso-PB; also called 2-bromopropane or 2-BP) among dry cleaners in New Jersey who have converted their machines from PERC to these new solvent products. Personal breathing zone and area samples were collected using the National Institute for Occupational Safety and Health Sampling and Analytical Method 1025, with a slight modification to gas chromatography conditions to facilitate better separation of n-PB from iso-PB. During the preliminary investigation, exposures to n-PB among some workers in two of three shops were measured that were greater than the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) for n-PB. The highest exposure measured among a dry cleaning machine operator was 54 parts per million (ppm) as an 8-hr time-weighted average, which is more than 5 times the ACGIH TLV of 10 ppm. The preliminary investigation also found that the work tasks most likely to result in the highest short-term exposures included the introduction of solvent to the machine, maintenance of the machine, unloading and handling of recently cleaned clothes, and interrupting the wash cycle of the machine. In addition, this assessment suggested that leaks may have contributed to exposure and may have resulted from normal machine wear over time, ineffective maintenance, and from the incompatibility of n-PB with gasket materials.

Identification of Splicing Quantitative Trait Loci (sQTL) in Drosophila melanogaster with Developmental Lead (Pb2+) Exposure.

PubMed

Qu, Wen; Gurdziel, Katherine; Pique-Regi, Roger; Ruden, Douglas M

2017-01-01

Lead (Pb) poisoning has been a major public health issue globally and the recent Flint water crisis has drawn nation-wide attention to its effects. To better understand how lead plays a role as a neurotoxin, we utilized the Drosophila melanogaster model to study the genetic effects of lead exposure during development and identified lead-responsive genes. In our previous studies, we have successfully identified hundreds of lead-responsive expression QTLs (eQTLs) by using RNA-seq analysis on heads collected from the Drosophila Synthetic Population Resource. Cis -eQTLs, also known as allele-specific expression (ASE) polymorphisms, are generally single-nucleotide polymorphisms in the promoter regions of genes that affect expression of the gene, such as by inhibiting the binding of transcription factors. Trans -eQTLs are genes that regulate mRNA levels for many genes, and are generally thought to be SNPs in trans -acting transcription or translation factors. In this study, we focused our attention on alternative splicing events that are affected by lead exposure. Splicing QTLs (sQTLs), which can be caused by SNPs that alter splicing or alternative splicing (AS), such as by changing the sequence-specific binding affinity of splicing factors to the pre-mRNA. We applied two methods in search for sQTLs by using RNA-seq data from control and lead-exposed w 1118 Drosophila heads. First, we used the fraction of reads in a gene that falls in each exon as the phenotype. Second, we directly compared the transcript counts among the various splicing isoforms as the phenotype. Among the 1,236 potential Pb-responsive sQTLs ( p < 0.0001, FDR < 0.39), mostly cis -sQTLs, one of the most distinct genes is Dscam1 (Down Syndrome Cell Adhesion Molecule), which has over 30,000 potential alternative splicing isoforms. We have also identified a candidate Pb-responsive trans -sQTL hotspot that appears to regulate 129 genes that are enriched in the "cation channel" gene ontology category, suggesting a model in which alternative splicing of these channels might lead to an increase in the elimination of Pb 2+ from the neurons encoding these channels. To our knowledge, this is the first paper that uses sQTL analyses to understand the neurotoxicology of an environmental toxin in any organism, and the first reported discovery of a candidate trans -sQTL hotspot.

Identification of Splicing Quantitative Trait Loci (sQTL) in Drosophila melanogaster with Developmental Lead (Pb2+) Exposure

PubMed Central

Qu, Wen; Gurdziel, Katherine; Pique-Regi, Roger; Ruden, Douglas M.

2017-01-01

Lead (Pb) poisoning has been a major public health issue globally and the recent Flint water crisis has drawn nation-wide attention to its effects. To better understand how lead plays a role as a neurotoxin, we utilized the Drosophila melanogaster model to study the genetic effects of lead exposure during development and identified lead-responsive genes. In our previous studies, we have successfully identified hundreds of lead-responsive expression QTLs (eQTLs) by using RNA-seq analysis on heads collected from the Drosophila Synthetic Population Resource. Cis-eQTLs, also known as allele-specific expression (ASE) polymorphisms, are generally single-nucleotide polymorphisms in the promoter regions of genes that affect expression of the gene, such as by inhibiting the binding of transcription factors. Trans-eQTLs are genes that regulate mRNA levels for many genes, and are generally thought to be SNPs in trans-acting transcription or translation factors. In this study, we focused our attention on alternative splicing events that are affected by lead exposure. Splicing QTLs (sQTLs), which can be caused by SNPs that alter splicing or alternative splicing (AS), such as by changing the sequence-specific binding affinity of splicing factors to the pre-mRNA. We applied two methods in search for sQTLs by using RNA-seq data from control and lead-exposed w1118 Drosophila heads. First, we used the fraction of reads in a gene that falls in each exon as the phenotype. Second, we directly compared the transcript counts among the various splicing isoforms as the phenotype. Among the 1,236 potential Pb-responsive sQTLs (p < 0.0001, FDR < 0.39), mostly cis-sQTLs, one of the most distinct genes is Dscam1 (Down Syndrome Cell Adhesion Molecule), which has over 30,000 potential alternative splicing isoforms. We have also identified a candidate Pb-responsive trans-sQTL hotspot that appears to regulate 129 genes that are enriched in the “cation channel” gene ontology category, suggesting a model in which alternative splicing of these channels might lead to an increase in the elimination of Pb2+ from the neurons encoding these channels. To our knowledge, this is the first paper that uses sQTL analyses to understand the neurotoxicology of an environmental toxin in any organism, and the first reported discovery of a candidate trans-sQTL hotspot. PMID:29114259

Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

PubMed

Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

2015-04-01

As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lead, mercury, and cadmium exposure and attention deficit hyperactivity disorder in children

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

Kim, Stephani; Arora, Monica; Fernandez, Cristina

Background: There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed attention deficit hyperactivity disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. Objectives: To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. Methods: We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA.more » The participants were matched on age group (5–8, 9–12 years), sex, race (African American or Caucasians and others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using inductively coupled plasma mass spectrometry. Results: Inside the LIA, the 27 cases had blood Pb geometric mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07–5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Conclusions: Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. -- Highlights: • Blood Pb levels are associated with ADHD diagnosis in children. • No association was found between blood Cd or Hg levels and ADHD. • Children living close to hazardous waste site need to reduce metal exposure.« less

Lead exposure and blood pressure among workers in diverse industrial plants in Kenya.

PubMed

Were, Faridah H; Moturi, M Charles; Gottesfeld, P; Wafula, Godfrey A; Kamau, Geoffrey N; Shiundu, Paul M

2014-01-01

The study evaluated airborne exposures and blood lead (BPb) levels in 233 production workers at six diverse industrial plants in Kenya. Blood and personal breathing zone air samples were collected and analyzed for lead (Pb) using atomic absorption spectroscopy. Blood pressure (BP) levels were measured using a standard mercury sphygmomanometer. The results indicated mean airborne Pb levels ± standard deviation (SD) as follows: 183.2 ± 53.6 μg/m(3) in battery recycling, 133.5 ± 39.6 μg/m(3) in battery manufacturing, 126.2 ± 39.9 μg/m(3) in scrap metal welding, 76.3 ± 33.2 μg/m(3) in paint manufacturing, 27.3 ± 12.1 μg/m(3) in a leather manufacturing, and 5.5 ± 3.6 μg/m(3) in a pharmaceutical plant. The mean airborne Pb levels exceeded the U.S. Occupational Safety and Health Administration (OSHA) 8-hr time-weighted average (TWA) permissible exposure limit (PEL) for Pb of 50 μg/m(3) in the battery manufacturing, battery recycling, welding, and paint manufacturing plants. Similarly, mean BPb concentrations exceeded the American Conference of Governmental Industrial Hygienists (ACGIH®) biological exposure index (BEI) for Pb of 30 μg/dl. A significant positive association was observed between BPb and breathing zone air Pb (R(2) = 0.73, P < 0.001). Approximately 30% of the production workers (N = 233) were in the hypertensive range with an average systolic and diastolic blood pressure (BP) of 134.7 ± 12.7 mmHg and 86.4 ± 8.9 mmHg, respectively. In the multivariate regression analysis, age, duration of work, airborne Pb and BPb levels were significantly associated (P < 0.05) with a change in BP. We recommend improved engineering controls, work practices, and personal hygiene to reduce Pb exposures. In addition, workers should undergo comprehensive medical surveillance to include BPb and BP testing, and airborne Pb assessments in all industries with significant lead exposures.

Patterns and trends in lead (Pb) concentrations in bald eagle (Haliaeetus leucocephalus) nestlings from the western Great Lakes region.

PubMed

Bruggeman, Jason E; Route, William T; Redig, Patrick T; Key, Rebecca L

2018-04-10

Most studies examining bald eagle (Haliaeetus leucocephalus) exposure to lead (Pb) have focused on adults that ingested spent Pb ammunition during the fall hunting season, often at clinical or lethal levels. We sampled live bald eagle nestlings along waterbodies to quantify Pb concentrations in 3 national park units and 2 nearby study areas in the western Great Lakes region. We collected 367 bald eagle nestling feather samples over 8 years during spring 2006-2015 and 188 whole blood samples over 4 years during spring 2010-2015. We used Tobit regression models to quantify relationships between Pb concentrations in nestling feathers and blood using study area, year, and nestling attributes as covariates. Pb in nestling feather samples decreased from 2006 to 2015, but there was no trend for Pb in blood samples. Pb concentrations in nestling feather and blood samples were significantly higher in study areas located closer to and within urban areas. Pb in feather and blood samples from the same nestling was positively correlated. Pb in feathers increased with nestling age, but this relationship was not observed for blood. Our results reflect how Pb accumulates in tissues as nestlings grow, with Pb in feathers and blood indexing exposure during feather development and before sampling, respectively. Some nestlings had Pb concentrations in blood that suggested a greater risk to sublethal effects from Pb exposure. Our data provides baselines for Pb concentrations in feathers and blood of nestling bald eagles from a variety of waterbody types spanning remote, lightly populated, and human-dominated landscapes.

Derivation of a target concentration of Pb in soil based on elevation of adult blood pressure

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

Stern, A.H.

1996-04-01

The increase in systolic blood pressure in males appears to be the most sensitive adult endpoint appropriate for deriving a health risk-based target level of lead (Ph) in soil. Because the response of blood pressure to blood Ph concentration (PbB) has no apparent threshold, traditional approaches based on the application of a Reference Dose (RfD) are not applicable. An alternative approach is presented based on a model which predicts the population shift in systolic blood pressure from ingestion of Pb contaminated soil as a simultaneous function of exposure to Pb in soil, the baseline distribution of blood Pb concentration inmore » the population and the baseline distribution of systolic pressure in the population. This model is analyzed using Monte Carlo analysis to predict the population distribution of systolic pressure resulting from Ph exposure. Based on this analysis, it is predicted that for adult males 18-65 years old, exposure to 1000 ppm Pb in soil will result in an increase of approximately 1 mm Hg systolic pressure, an increase in the incidence of systolic hypertension (i.e., systolic pressure >140 mm Hg) of approximately 1% and an increase in PbB of 1-3 {mu}g/dl. Based on the proposition that these adverse effects can be considered de minimis, 1000 ppm Ph in soil is proposed as a target soil concentration for adult exposure. Available data do not appear to be adequate to predict the newborn PbB level which would result from exposure to this soil level during pregnancy, 36 refs., 6 figs.« less

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.

Assessment of risks to ground-feeding songbirds from lead in the Coeur d'Alene Basin, Idaho, USA.

PubMed

Sample, Bradley E; Hansen, James A; Dailey, Anne; Duncan, Bruce

2011-10-01

Previous assessment of ecological risks within the Coeur d'Alene River Basin identified Pb as a key risk driver for ground-feeding songbirds. Because this conclusion was based almost exclusively on literature data, its strength was determined to range from low to moderate. With the support of the US Environmental Protection Agency (USEPA), the US Fish and Wildlife Service collected site-specific data to address the uncertainty associated with Pb risks to songbirds. These data, plus those from the previous Coeur d'Alene Basin ecological risk assessment, were integrated, and risks to ground-feeding songbirds were reevaluated. These site-specific data were also used to develop updated preliminary remedial goals (PRGs) for Pb in soils that would be protective of songbirds. Available data included site-specific Pb concentrations in blood, liver, and ingesta from 3 songbird species (American robin, song sparrow, and Swainson's thrush), colocated soil data, and soil data from other locations in the basin. Semi-log regression models based on the association between soil Pb and tissue Pb concentrations were applied to measured soil concentrations from the previous risk assessment to estimate Pb exposures in riparian and adjacent upland habitats throughout the Coeur d'Alene Basin. Measured and estimated tissue or dietary exposure was tabulated for 3 areas plus the reference, and then compared to multiple effects measures. As many as 6 exposure-effect metrics were available for assessing risk in any one area. Analyses of site-specific tissue- and diet-based exposure data indicate that exposure of ground-feeding songbirds to Pb in the Coeur d'Alene Basin is sufficient to result in adverse effects. Because this conclusion is based on multiple exposure-effect metrics that include site-specific data, the strength of this conclusion is high. Ecological PRGs were developed by integrating the site-specific regression models with tissue and dietary effect levels to create exposure models, which were solved for the soil concentration that produced an exposure estimate equal to the effect level (i.e., the ecological PRG). The lowest PRG obtained for any species' exposure-effect measure combination was 490 mg/kg for subclinical effects due to Pb in the blood of American robins; the highest was 7200 mg/kg for severe clinical effects due to Pb in the blood of song sparrows. Because the lowest ground-feeding songbird PRG was comparable to multiple cleanup goals developed for the basin (i.e., soil invertebrates, wildlife populations, and human health), in addition to the site-specific cleanup level of 530 mg Pb/kg sediment for the protection of waterfowl (USEPA 2002) the USEPA has made a risk-management determination that a site-specific Pb cleanup level of 530 mg/kg in soil would be protective of songbirds in the Coeur d'Alene Basin. Copyright © 2011 SETAC.

A discussion about public health, lead and Legionella pneumophila in drinking water supplies in the United States.

PubMed

Rosen, Michael B; Pokhrel, Lok R; Weir, Mark H

2017-07-15

Lead (Pb) in public drinking water supplies has garnered much attention since the outset of the Flint water crisis. Pb is a known hazard in multiple environmental matrices, exposure from which results in long-term deleterious health effects in humans. This discussion paper aims to provide a succinct account of environmental Pb exposures with a focus on water Pb levels (WLLs) in the United States. It is understood that there is a strong correlation between WLLs and blood Pb levels (BLLs), and the associated health effects. However, within the Flint water crisis, more than water chemistry and Pb exposure occurred. A cascade of regulatory and bureaucratic failures culminated in the Flint water crisis. This paper will discuss pertinent regulations and responses including their limitations after an overview of the public health effects from Pb exposure as well as discussion on our limitations on monitoring and mitigating Pb in tap water. As the Flint water crisis also included increased Legionnares' disease, caused by Legionella pneumophila, this paper will discuss factors influencing L. pneumophila growth. This will highlight the systemic nature of changes to water chemistry and public health impacts. As we critically analyze these important aspects of water research, we offer discussions to stimulate future water quality research from a new and systemic perspective to inform and guide public health decision-making. Copyright © 2017 Elsevier B.V. All rights reserved.

Differences in oxidative stress between young Canada geese and mallards exposed to lead-contaminated sediment

USGS Publications Warehouse

Mateo, R.; Hoffman, D.J.

2001-01-01

Lead (Pb) exposure causes an increase in tissue lipid peroxides and variation in glutathione (GSH) concentration, which can be related to peroxidative damage of cell membranes in Pb poisoned animals. Species and individual variation in sensitivity to Pb poisoning among animals may be due to differential resistance to oxidative stress. We compared the effects of oxidative stress caused by Pb exposure (1.7, 414 and 828 ig/g of diet) for the first six weeks in growing young of two species of waterfowl, Canada geese (Branta canadensis) and mallards (Anas platyrhynchos), with the first species being possibly more sensitive to Pb poisoning based on previous field and laboratory observations. Blood and liver Pb concentrations increased more in mallards than in geese; this may be explained on the basis of body weight, being 3.2 times higher in geese, and hepatic metabolism where GSH-S-transferase activity is 2.9 fold higher in geese and presumably has a role in the binding of Pb to GSH and subsequent biliary excretion. In contrast, mallards showed higher hepatic levels of GSH and activities of GSH peroxidase (GPX) and GSH reductase (GR). Although both species showed an increase in hepatic GSH concentration with Pb exposure, the increase of lipid peroxidation with Pb exposure was more significant in geese. Within treatment groups, hepatic GSH concentrations were inversely related to liver Pb concentration in both species, which may correspond to the role of GSH in Pb excretion. Hepatic GSH was also inversely related to hepatic lipid peroxidation, but only in mallards and in agreement with the differences observed in GPX and GR activities. The lower resistance to lipid peroxidation of Canada geese may explain why birds of this species found dead in the field by Pb shot ingestion often have a lower number of shot in the gizzard and lower liver Pb concentrations than mallards.

A developmental perspective on early-life exposure to neurotoxicants.

PubMed

Bellinger, David C; Matthews-Bellinger, Julia A; Kordas, Katarzyna

2016-09-01

Studies of early-life neurotoxicant exposure have not been designed, analyzed, or interpreted in the context of a fully developmental perspective. The goal of this paper is to describe the key principles of a developmental perspective and to use examples from the literature to illustrate the relevance of these principles to early-life neurotoxicant exposures. Four principles are discussed: 1) the effects of early-life neurotoxicant exposure depend on a child's developmental context; 2) deficits caused by early-life exposure initiate developmental cascades that can lead to pathologies that differ from those observed initially; 3) early-life neurotoxicant exposure has intra-familial and intergenerational impacts; 4) the impacts of early-life neurotoxicant exposure influence a child's ability to respond to future insults. The first principle is supported by considerable evidence, but the other three have received much less attention. Incorporating a developmental perspective in studies of early-life neurotoxicant exposures requires prospective collection of data on a larger array of covariates than usually considered, using analytical approaches that acknowledge the transactional processes between a child and the environment and the phenomenon of developmental cascades. Consideration of early-life neurotoxicant exposure within a developmental perspective reveals that many issues remain to be explicated if we are to achieve a deep understanding of the societal health burden associated with early-life neurotoxicant exposures. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Changes of lead speciation and microbial toxicity in soil treated with repeated Pb exposure in the presence of BDE209.

PubMed

Zhang, Rong; Zhang, Wei; Liu, Gao; Lin, Kuangfei; Fu, Rongbing

2016-03-01

Lead (Pb) and decabromodiphenyl ether (BDE209) are main pollutants at electric waste (e-waste) recycling sites (EWRSs), and their joint toxicological effects have received extensive attention. Frequently, soil pollution at EWRSs usually results from the occurrence of repeated single or multiple pollution events, with continuous impacts on soil microorganisms. Therefore, a laboratory incubation study was conducted to determine Pb bioavailability and microbial toxicity in repeated Pb-polluted soil in the presence of BDE209 for the first time. We evaluated the impacts of repetitive exposure trials on chemical fractions of Pb, and the results showed that repeated single Pb pollution event resulted in an increase of carbonates fraction of Pb, which was different from one-off single Pb exposure. Moreover, one-off Pb-treated groups exhibited higher I R (reduced partition index) values on day 30 and all treatments remained the same I R level at the end of incubation period. The parameters of microbial toxicity were well reflected by soil enzymes. During the entire incubation, the dehydrogenase and urease activities were significantly inhibited by Pb (P < 0.01), and BDE209 supply could weaken the adverse influence. Additionally, significant correlations between available or metastable Pb and the two soil enzymes were clearly observed (P < 0.05 or 0.01). Such observations would provide useful information for ecological effects of Pb and BDE209 at EWRSs.

Identifying natural and anthropogenic sources of metals in urban and rural soils using GIS-based data, PCA, and spatial interpolation

PubMed Central

Davis, Harley T.; Aelion, C. Marjorie; McDermott, Suzanne; Lawson, Andrew B.

2009-01-01

Determining sources of neurotoxic metals in rural and urban soils is important for mitigating human exposure. Surface soil from four areas with significant clusters of mental retardation and developmental delay (MR/DD) in children, and one control site were analyzed for nine metals and characterized by soil type, climate, ecological region, land use and industrial facilities using readily-available GIS-based data. Kriging, principal component analysis (PCA) and cluster analysis (CA) were used to identify commonalities of metal distribution. Three MR/DD areas (one rural and two urban) had similar soil types and significantly higher soil metal concentrations. PCA and CA results suggested that Ba, Be and Mn were consistently from natural sources; Pb and Hg from anthropogenic sources; and As, Cr, Cu, and Ni from both sources. Arsenic had low commonality estimates, was highly associated with a third PCA factor, and had a complex distribution, complicating mitigation strategies to minimize concentrations and exposures. PMID:19361902

The relation of low-level prenatal lead exposure to behavioral indicators of attention in Inuit infants in Arctic Quebec.

PubMed

Plusquellec, P; Muckle, G; Dewailly, E; Ayotte, P; Jacobson, S W; Jacobson, J L

2007-01-01

The aim of this study was to investigate the association between prenatal exposure to lead (Pb) and several aspects of behavioral function during infancy through examiner ratings and behavioral coding of video recordings. The sample consisted of 169 11-month-old Inuit infants from Arctic Quebec. Umbilical cord and maternal blood samples were used to document prenatal exposure to Pb. Average blood Pb levels were 4.6 mug/dL and 5.9 mug/dL in cord and maternal samples respectively. The Behavior Rating Scales (BRS) from the Bayley Scales of Infant Development (BSID-II) were used to assess behavior. Attention was assessed through the BRS and behavioral coding of video recordings taken during the administration of the BSID-II. Whereas the examiner ratings of behaviors detected very few associations with prenatal Pb exposure, cord blood Pb concentrations were significantly related to the direct observational measures of infant attention, after adjustment for confounding variables. These data provide evidence that increasing the specificity and the precision of the behavioral assessment has considerable potential for improving our ability to detect low-to-moderate associations between neurotoxicants, such Pb and infant behavior.

Lead, mercury, and cadmium exposure and attention deficit hyperactivity disorder in children.

PubMed

Kim, Stephani; Arora, Monica; Fernandez, Cristina; Landero, Julio; Caruso, Joseph; Chen, Aimin

2013-10-01

There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed attention deficit hyperactivity disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5-8, 9-12 years), sex, race (African American or Caucasians and others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using inductively coupled plasma mass spectrometry. Inside the LIA, the 27 cases had blood Pb geometric mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07-5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. © 2013 Published by Elsevier Inc.

Lead, Mercury, and Cadmium Exposure and Attention Deficit Hyperactivity Disorder in Children

PubMed Central

Kim, Stephani; Arora, Monica; Fernandez, Cristina; Caruso, Joseph; Landero, Julio; Chen, Aimin

2013-01-01

Background There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed Attention Deficit Hyperactivity Disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. Objectives To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. Methods We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5–8, 9–12 years), sex, race (African American or Caucasians and Others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using Inductively Coupled Plasma Mass Spectrometry. Results Inside the LIA, the 27 cases had blood Pb Geometric Mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07–5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Conclusions Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. PMID:24034783

Interaction betwen Lead and Bone Protein to Affect Bone Calcium Level Using UV-Vis Spectroscopy

NASA Astrophysics Data System (ADS)

Noor, Z.; Azharuddin, A.; Aflanie, I.; Kania, N.; Suhartono, E.

2018-05-01

This present study aim to evaluate the interactions between lead (Pb) and with bone protein by UV-Vis approach. In addition, this prsent study also aim to investigate the effect of Pb on bone calcium (Ca) level. The present study was a true experimental study design to examine the impact of Pb exposure in bone of male rats (Rattus novergicus). The study involved 5 groups, P1 was the control group, while the other (P2-P5) were the case group with exposure of Pb in different concentration within 4 weeks. At the end of the exposure, the interaction between Pb and protein was determined using UV-Vis spectrophotometric method, and the Ca level was determined using permanganometric method. The results shows that that there is an interaction between Pb and bone protein. The result also shows that the value of the binding constant of Protein-Pb is 32.71. It means Pb have an high affinity to bind with bone protein, which promote a further reaction to induced the release of bone Ca from the bone protein. In conclusion, this present study found an obvious relationship between Pb and bone protein which promote a further reaction to increase the releasing of bone calcium.

Effects of dietary lead exposure on vitamin levels in great tit nestlings - An experimental manipulation.

PubMed

Ruiz, Sandra; Espín, Silvia; Rainio, Miia; Ruuskanen, Suvi; Salminen, Juha-Pekka; Lilley, Thomas M; Eeva, Tapio

2016-06-01

Exposure to metal pollution negatively affects animal physiology, including nutrient metabolism, but in the wild an effect can seldom be attributed to a single metal. Moreover, little is known about how the metabolism of vitamins, essential micronutrients for developing juveniles, is affected by toxic metals. Therefore we experimentally investigated the effects of lead (Pb), a widespread toxic metal, on four fat-soluble vitamins A (total and retinol), D3, E (total and α-tocopherol) and K and carotenoids (lutein, zeaxanthin and unidentified) in great tit (Parus major) nestlings. In addition to a control group where no Pb was provided, two Pb-dosed groups were compared to a metal exposed group in the vicinity of a Ni-Cu smelter. We examined whether Pb treatment affects vitamin homeostasis and how the response of Pb-treated birds relates to that of a population under industrial exposure of Pb and other metals. For this purpose, vitamin and carotenoid levels were quantified with UPLC-MS from plasma of 7 days-old nestlings. All metal exposed groups showed increased vitamin A and retinol levels. However, vitamin levels were not directly associated with fecal Pb levels, with the exception of retinol, which was positively correlated with fecal Pb. Alpha-tocopherol, lutein and zeaxanthin levels were positively associated with body mass and wing growth rate. To conclude, Pb exposure increased plasma vitamin A and retinol levels while the levels of other vitamins and carotenoids rather reflected secondary pollution effects via differences in habitat and diet quality at the smelter site. Our findings suggest Pb exposed nestlings may allocate the vitamins needed for growth and development to fight the physiological stress thus compromising their fitness. Copyright © 2016 Elsevier Ltd. All rights reserved.

Placental transfer and concentrations of cadmium, mercury, lead, and selenium in mothers, newborns, and young children

PubMed Central

Chen, Zhu; Myers, Robert; Wei, Taiyin; Bind, Eric; Kassim, Prince; Wang, Guoying; Ji, Yuelong; Hong, Xiumei; Caruso, Deanna; Bartell, Tami; Gong, Yiwei; Strickland, Paul; Navas-Acien, Ana; Guallar, Eliseo; Wang, Xiaobin

2015-01-01

There is an emerging hypothesis that exposure to cadmium (Cd), mercury (Hg), lead (Pb), and selenium (Se) in utero and early childhood could have long-term health consequences. However, there are sparse data on early life exposures to these elements in US populations, particularly in urban minority samples. This study measured levels of Cd, Hg, Pb, and Se in 50 paired maternal, umbilical cord, and postnatal blood samples from the Boston Birth Cohort (BBC). Maternal exposure to Cd, Hg, Pb, and Se was 100% detectable in red blood cells (RBCs), and there was a high degree of maternal–fetal transfer of Hg, Pb, and Se. In particular, we found that Hg levels in cord RBCs were 1.5 times higher than those found in the mothers. This study also investigated changes in concentrations of Cd, Hg, Pb, and Se during the first few years of life. We found decreased levels of Hg and Se but elevated Pb levels in early childhood. Finally, this study investigated the association between metal burden and preterm birth and low birthweight. We found significantly higher levels of Hg in maternal and cord plasma and RBCs in preterm or low birthweight births, compared with term or normal birthweight births. In conclusion, this study showed that maternal exposure to these elements was widespread in the BBC, and maternal–fetal transfer was a major source of early life exposure to Hg, Pb, and Se. Our results also suggest that RBCs are better than plasma at reflecting the trans-placental transfer of Hg, Pb, and Se from the mother to the fetus. Our study findings remain to be confirmed in larger studies, and the implications for early screening and interventions of preconception and pregnant mothers and newborns warrant further investigation. PMID:24756102

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.

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.

Bone lead levels in an environmentally exposed elderly population in shanghai, China.

PubMed

Specht, Aaron J; Lin, Yanfen; Xu, Jian; Weisskopf, Marc; Nie, Linda H

2018-06-01

This study looked at measurements of lead (Pb) in a pilot population of environmentally exposed elderly residents of Shanghai, China and presented the first set of bone Pb data on an elderly Chinese population. We found that with environmental exposures in this population using K-shell x-ray fluorescence (KXRF) bone Pb measurements 40% of the individuals had bone Pb levels above the nominal detection limit with an average bone lead level of 4.9 ± 3.6 μg/g. This bone lead level is lower than comparable values from previous studies of community dwelling adults in US cities. This population had a slightly higher geometric mean blood Pb of 2.6 μg/dL than the adult US population. The main conclusion of this data is that in Shanghai there is environmental exposure to Pb, measured through blood and bone, which should be further investigated to assess the health impact of this exposure. Copyright © 2018. Published by Elsevier B.V.

From the Cover: 7,8-Dihydroxyflavone Rescues Lead-Induced Impairment of Vesicular Release: A Novel Therapeutic Approach for Lead Intoxicated Children.

PubMed

Zhang, Xiao-Lei; McGlothan, Jennifer L; Miry, Omid; Stansfield, Kirstie H; Loth, Meredith K; Stanton, Patric K; Guilarte, Tomás R

2018-01-01

Childhood lead (Pb2+) intoxication is a public health problem of global proportion. Lead exposure during development produces multiple effects on the central nervous system including impaired synapse formation, altered synaptic plasticity, and learning deficits. In primary hippocampal neurons in culture and hippocampal slices, Pb2+ exposure inhibits vesicular release and reduces the number of fast-releasing sites, an effect associated with Pb2+ inhibition of NMDA receptor-mediated trans-synaptic Brain-Derived Neurotrophic Factor (BDNF) signaling. The objective of this study was to determine if activation of TrkB, the cognate receptor for BDNF, would rescue Pb2+-induced impairments of vesicular release. Rats were chronically exposed to Pb2+ prenatally and postnatally until 50 days of age. This chronic Pb2+ exposure paradigm enhanced paired-pulse facilitation of synaptic potentials in Schaffer collateral-CA1 synapses in the hippocampus, a phenomenon indicative of reduced vesicular release probability. Decreased vesicular release probability was confirmed by both mean-variance analysis and direct 2-photon imaging of vesicular release from hippocampal slices of rats exposed to Pb2+in vivo. We also found a Pb2+-induced impairment of calcium influx in Schaffer collateral-CA1 synaptic terminals. Intraperitoneal injections of Pb2+ rats with the TrkB receptor agonist 7,8-dihydroxyflavone (5 mg/kg) for 14-15 days starting at postnatal day 35, reversed all Pb2+-induced impairments of presynaptic transmitter release at Schaffer collateral-CA1 synapses. This study demonstrates for the first time that in vivo pharmacological activation of TrkB receptors by small molecules such as 7,8-dihydroxyflavone can reverse long-term effects of chronic Pb2+ exposure on presynaptic terminals, pointing to TrkB receptor activation as a promising therapeutic intervention in Pb2+-intoxicated children. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

New and evolving concepts in the neurotoxicology of lead

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

White, L.D.; Cory-Slechta, D.A.; Gilbert, M.E.

2007-11-15

Lead (Pb) is a xenobiotic metal with no known essential function in cellular growth, proliferation, or signaling. Decades of research characterizing the toxicology of Pb have shown it to be a potent neurotoxicant, especially during nervous system development. New concepts in the neurotoxicology of Pb include advances in understanding the mechanisms and cellular specificity of Pb. Experimental studies have shown that stress can significantly alter the effects of Pb, effects that could potentially be mediated through alterations in the interactions of glucocorticoids with the mesocorticolimbic dopamine system of the brain. Elevated stress, with corresponding elevated glucocorticoid levels, has been postulatedmore » to contribute to the increased levels of many diseases and dysfunctions in low socioeconomic status populations. Cellular models of learning and memory have been utilized to investigate the potential mechanisms of Pb-induced cognitive deficits. Examination of long-term potentiation in the rodent hippocampus has revealed Pb-induced increases in threshold, decreases in magnitude, and shorter retention times of synaptic plasticity. Structural plasticity in the form of adult neurogenesis in the hippocampus is also impacted by Pb exposure. The action of Pb on glutamate release, NMDA receptor function, or structural plasticity may underlie perturbations in synaptic plasticity and contribute to learning impairments. In addition to providing insight into potential mechanisms of Pb-induced cognitive deficits, cellular models offer an opportunity to investigate direct effects of Pb on isolated biological substrates. A target of interest is the 78-kDa molecular chaperone glucose-regulated protein (GRP78). GRP78 chaperones the secretion of the cytokine interleukin-6 (IL-6) by astrocytes. In vitro evidence shows that Pb strongly binds to GRP78, induces GRP78 aggregation, and blocks IL-6 secretion in astroglial cells. These findings provide evidence for a significant chaperone deficiency in Pb-exposed astrocytes in culture. In the long term, chaperone deficiency could underlie protein conformational diseases such as Alzheimer's Disease (AD). Lead exposure in early life has been implicated in subsequent progression of amyloidogenesis in rodents during old age. This exposure resulted in an increase in proteins associated with AD pathology viz., beta-amyloid precursor protein ({beta}-APP), and beta-amyloid (A{beta}). These four new lines of research comprise compelling evidence that exposures to Pb have adverse effects on the nervous system, that environmental factors increase nervous system susceptibility to Pb, and that exposures in early life may cause neurodegeneration in later life.« less

The relation of environmental contaminants exposure to behavioral indicators in Inuit preschoolers in Arctic Quebec.

PubMed

Plusquellec, P; Muckle, G; Dewailly, E; Ayotte, P; Bégin, G; Desrosiers, C; Després, C; Saint-Amour, D; Poitras, K

2010-01-01

Although lead (Pb) exposure has been identified as an important risk factor in child behavioral development, less is known regarding the relation between child behavior and exposure to polychlorinated biphenyls (PCBs) and mercury (Hg). Inuit children are particularly exposed to these chemicals and the aim of this study was to investigate the association between prenatal and postnatal exposure to Pb, PCBs, Hg and several aspects of behavioral function in Inuit preschoolers. The sample consisted of one hundred and ten 5-year-old Inuit children from Arctic Quebec. An umbilical cord blood sample was used to document prenatal exposure to Pb, PCBs and Hg. Child blood samples were collected at age 5 and the same contaminants were measured. A modified version of the Infant Behavior Rating Scale from the Bayley Scales of Infant Development-II was used to assess child behavior through examiners' ratings. Furthermore, attention, activity and emotional outcomes were assessed through behavioral coding of video recordings taken during fine motor testing. Pb exposure during childhood was associated with examiners ratings of greater impulsivity, irritability and with coding of observed inattention. Prenatal exposure to PCB 153 correlated with the examiners ratings of increased state of unhappiness and anxiety during the testing session, which was corroborated from video coding since cord PCB 153 was related to fewer manifestations of positive affects. No association was found with Hg exposure. These data corroborated those from previous Pb cohort studies and revealed an association between prenatal PCBs exposure and emotional outcomes in preschoolers. 2009 Elsevier Inc. All rights reserved.

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.

Vestibular dysfunction in the adult CBA/CaJ mouse after lead and cadmium treatment

PubMed Central

Klimpel, Katarina E. M.; Lee, Min Young; King, W. Michael; Raphael, Yehoash; Schacht, Jochen; Neitzel, Richard L.

2017-01-01

OBJECTIVES The vestibular system allows the perception of position and motion and its dysfunction presents as motion impairment, vertigo and balance abnormalities, leading to debilitating psychological discomfort and difficulty performing daily tasks. Although declines and deficits in vestibular function have been noted in rats exposed to lead (Pb) and in humans exposed to Pb and cadmium (Cd), no studies have directly examined the pathological and pathophysiological effects upon the vestibular apparatus of the inner ear. METHODS Eighteen young adult mice were exposed through their drinking water (3 mM Pb, 300 μM Cd, or a control treatment) for 10 weeks. Before and after treatment, they underwent a vestibular assessment, consisting of a rotarod performance test and a novel head stability test to measure the vestibulocolic reflex. At the conclusion of the study, the utricles were analyzed immunohistologically for condition of hair cells and nerve fibers. RESULTS Increased levels of Pb exposure correlated with decreased head stability in space; no significant decline in performance on rotarod test was found. No damage to the hair cells or the nerve fibers of the utricle was observed in histology. CONCLUSIONS The young adult CBA/CaJ mouse is able to tolerate occupationally-relevant Pb and Cd exposure well, but the correlation between Pb exposure and reduced head stability suggests that Pb exposure causes a decline in vestibular function. PMID:27257108

Blood lead levels following consumption of game meat in Italy.

PubMed

Fustinoni, Silvia; Sucato, Sabrina; Consonni, Dario; Mannucci, Pier Mannuccio; Moretto, Angelo

2017-05-01

The aim of this study was to measure lead (Pb) levels in blood (Pb-blood) in consumers of game meat, taking into account other possible sources of lead exposure. A spot blood sample was obtained from 95 subjects, and a questionnaire was used to collect general information and data on game meat consumption, hunting, wine drinking and other possible sources of lead exposure. Pb-blood was measured by inductively coupled plasma-mass spectrometry. Pb-blood was not influenced by age, sex, residence in an urban or rural area, consumption of game meat, tobacco smoking or hobbies associated with potential exposure to lead, and median Pb-blood was 1.7 (5th-95th percentile 1.0-5.3)µg/dL and 3.4 (0.9-6.1)µg/dL for game meat non-eaters and eater, respectively. A multiple linear regression analysis (containing the covariates sex, age, hunting, wine drinking, game meat consumption, tobacco smoking, shooting range, and occupational exposure) found an association with hunting (Pb-blood almost double in hunters) and wine drinking (40% higher in drinkers) but not with consumption of game meat or other parameters. Whether the higher Pb-blood level was due to inhalation of lead fumes while shooting with lead ammunition, to handling lead ammunition or both could not be ascertained. Copyright © 2017 Elsevier Inc. All rights reserved.

Glycogen metabolism in brain and neurons - astrocytes metabolic cooperation can be altered by pre- and neonatal lead (Pb) exposure.

PubMed

Baranowska-Bosiacka, Irena; Falkowska, Anna; Gutowska, Izabela; Gąssowska, Magdalena; Kolasa-Wołosiuk, Agnieszka; Tarnowski, Maciej; Chibowska, Karina; Goschorska, Marta; Lubkowska, Anna; Chlubek, Dariusz

2017-09-01

Lead (Pb) is an environmental neurotoxin which particularly affects the developing brain but the molecular mechanism of its neurotoxicity still needs clarification. The aim of this paper was to examine whether pre- and neonatal exposure to Pb (concentration of Pb in rat offspring blood below the "threshold level") may affect the brain's energy metabolism in neurons and astrocytes via the amount of available glycogen. We investigated the glycogen concentration in the brain, as well as the expression of the key enzymes involved in glycogen metabolism in brain: glycogen synthase 1 (Gys1), glycogen phosphorylase (PYGM, an isoform active in astrocytes; and PYGB, an isoform active in neurons) and phosphorylase kinase β (PHKB). Moreover, the expression of connexin 43 (Cx43) was evaluated to analyze whether Pb poisoning during the early phase of life may affect the neuron-astrocytes' metabolic cooperation. This work shows for the first time that exposure to Pb in early life can impair brain energy metabolism by reducing the amount of glycogen and decreasing the rate of its metabolism. This reduction in brain glycogen level was accompanied by a decrease in Gys1 expression. We noted a reduction in the immunoreactivity and the gene expression of both PYGB and PYGM isoform, as well as an increase in the expression of PHKB in Pb-treated rats. Moreover, exposure to Pb induced decrease in connexin 43 immunoexpression in all the brain structures analyzed, both in astrocytes as well as in neurons. Our data suggests that exposure to Pb in the pre- and neonatal periods results in a decrease in the level of brain glycogen and a reduction in the rate of its metabolism, thereby reducing glucose availability, which as a further consequence may lead to the impairment of brain energy metabolism and the metabolic cooperation between neurons and astrocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

The Influence of Declining Air Lead Levels on Blood Lead–Air Lead Slope Factors in Children

PubMed Central

Richmond-Bryant, Jennifer; Davis, Allen; Cohen, Jonathan; Lu, Shou-En; Svendsgaard, David; Brown, James S.; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa C.; Kotchmar, Dennis; Hines, Erin P.; Ross, Mary

2014-01-01

Background: It is difficult to discern the proportion of blood lead (PbB) attributable to ambient air lead (PbA), given the multitude of lead (Pb) sources and pathways of exposure. The PbB–PbA relationship has previously been evaluated across populations. This relationship was a central consideration in the 2008 review of the Pb national ambient air quality standards. Objectives: The objectives of this study were to evaluate the relationship between PbB and PbA concentrations among children nationwide for recent years and to compare the relationship with those obtained from other studies in the literature. Methods: We merged participant-level data for PbB from the National Health and Nutrition Examination Survey (NHANES) III (1988–1994) and NHANES 9908 (1999–2008) with PbA data from the U.S. Environmental Protection Agency. We applied mixed-effects models, and we computed slope factor, d[PbB]/d[PbA] or the change in PbB per unit change in PbA, from the model results to assess the relationship between PbB and PbA. Results: Comparing the NHANES regression results with those from the literature shows that slope factor increased with decreasing PbA among children 0–11 years of age. Conclusion: These findings suggest that a larger relative public health benefit may be derived among children from decreases in PbA at low PbA exposures. Simultaneous declines in Pb from other sources, changes in PbA sampling uncertainties over time largely related to changes in the size distribution of Pb-bearing particulate matter, and limitations regarding sampling size and exposure error may contribute to the variability in slope factor observed across peer-reviewed studies. Citation: Richmond-Bryant J, Meng Q, Davis A, Cohen J, Lu SE, Svendsgaard D, Brown JS, Tuttle L, Hubbard H, Rice J, Kirrane E, Vinikoor-Imler LC, Kotchmar D, Hines EP, Ross M. 2014. The Influence of declining air lead levels on blood lead–air lead slope factors in children. Environ Health Perspect 122:754–760; http://dx.doi.org/10.1289/ehp.1307072 PMID:24667492

Sampling for Lead in Drinking Water

EPA Science Inventory

Sampling protocols for lead in water can be broadly categorized based on their intended purpose of 1) Pb regulatory compliance/corrosion control efficacy, 2) Pb plumbing source determination or Pb type identification, and 3) Pb exposure assessment. Choosing the appropriate protoc...

Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure.

PubMed

Barbosa, Fernando; Ramires, Irene; Rodrigues, Maria Heloísa C; Saint' Pierre, Tatiana D; Curtius, Adilson J; Buzalaf, Marilia R; Gerlach, Raquel F; Tanus-Santos, José E

2006-09-01

We examined the effect of age and sex on the relationship between the concentrations of Pb in blood (Pb-B) and in plasma (Pb-P) in an adult population with a history of lead exposure. Pb-P was determined by inductively coupled plasma mass spectrometry (ICP-MS) and Pb-B by graphite furnace atomic absorption spectrometry (GF AAS). We studied 154 adults (56 men and 98 women) from 18 to 60-year old. Pb-B levels varied from 10.0 to 428.0 microg/L, with a mean of 76 microg/L. Blood lead levels varied from 10.0 to 428.0 microg/L in men (mean, 98.3 microg/L) and from 10.0 to 263.0 microg/L (mean, 62.8 microg/L) in women. Corresponding Pb-Ps were 0.02-2.9 microg/L (mean, 0.66 microg/L) and 0.02-1.5 microg/L (mean, 0.42 microg/L) in men and women, respectively. The relationship between Pb-B and Pb-P was found to be curvilinear (r = 0.757, P < 0.001 Spearman's correlation). The two quantities are related by the line y = 0.0006x(1492) (y = Pb-P, and x = Pb-B). The %Pb-P/Pb-B ratio ranged from 0.03% to 1.85%. A positive association was found between %Pb-P/Pb-B ratio and Pb-B levels. When data were separated by sex, this association was also relevant for men (y = 0.0184x(0.702)) and women (y = 0.0534x(0.5209)) (y = %Pb-P/Pb-B and x = Pb-B). Moreover, we found an interesting positive correlation between Log (Pb-P/Pb-B) and age for women (r = 0.31, P < 0.0001) and a negative correlation for men (r = -0.164, P = 0.07). Taken together, these results suggest contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. Moreover, sex might play an important role in the metabolism of lead, implying further consideration on the kinetic models constructed of lead toxicity.

Lead Hepatotoxicity and Potential Health Effects

EPA Science Inventory

Occupational and environmental exposures to lead (Pb), one of the toxic metal pollutants, is of global concern. Health risks are increasingly associated with environmental exposures to Pb emissions from, for example, the widespread use of leaded gasoline in developing countries. ...

Comparison in waterborne Cu, Ni and Pb bioaccumulation kinetics between different gammarid species and populations: Natural variability and influence of metal exposure history.

PubMed

Urien, N; Farfarana, A; Uher, E; Fechner, L C; Chaumot, A; Geffard, O; Lebrun, J D

2017-12-01

Kinetic parameters (uptake from solution and elimination rate constants) of Cu, Ni and Pb bioaccumulation were determined from two Gammarus pulex and three Gammarus fossrum wild populations collected from reference sites throughout France in order to assess the inter-species and the natural inter-population variability of metal bioaccumulation kinetics in that sentinel organism. For that, each population was independently exposed for seven days to either 2.5μgL -1 Cu (39.3nM), 40μgL -1 Ni (681nM) or 10μgL -1 Pb (48.3nM) in laboratory controlled conditions, and then placed in unexposed microcosms for a 7-day depuration period. In the same way, the possible influence of metal exposure history on subsequent metal bioaccumulation kinetics was addressed by collecting wild gammarids from three populations inhabiting stations contaminated either by Cd, Pb or both Pb and Ni (named pre-exposed thereafter). In these pre-exposed organisms, assessment of any changes in metal bioaccumulation kinetics was achieved by comparison with the natural variability of kinetic parameters defined from reference populations. Results showed that in all studied populations (reference and pre-exposed) no significant Cu bioaccumulation was observed at the exposure concentration of 2.5μgL -1 . Concerning the reference populations, no significant differences in Ni and Pb bioaccumulation kinetics between the two species (G. pulex and G. fossarum) was observed allowing us to consider all the five reference populations to determine the inter-population natural variability, which was found to be relatively low (kinetic parameters determined for each population remained within a factor of 2 of the minimum and maximum values). Organisms from the population exhibiting a Pb exposure history presented reduced Ni uptake and elimination rate constants, whereas no influence on Ni kinetic parameters was observed in organisms from the population exhibiting an exposure history to both Ni and Pb. Furthermore Pb bioaccumulation kinetics were unaffected whatever the condition of pre-exposure in natural environment. Finally, these results highlight the complexity of confounding factors, such as metal exposure history, that influence metal bioaccumulation processes and showed that pre-exposure to one metal can cause changes in the bioaccumulation kinetics of other metals. These results also address the question of the underlying mechanisms developed by organisms to cope with metal contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

Lead remediation and changes in human lead exposure: some physiological and biokinetic dimensions.

PubMed

Mushak, Paul

2003-02-15

This paper presents a qualitative and quantitative analysis of the various aspects of lead remediation effectiveness with particular reference to human health risk assessment. One of the key elements of lead remediation efforts at such sites as those under the Superfund program deals with populations at elevated exposure and toxicity risk in the proximity of, or at, the site of remediation, especially remediation workers, workers at other tasks on sites that were remediated down to some action level of lead concentration in soils, and groups at risk in nearby communities. A second element has to do with how one measures or models lead exposure changes with special reference to baseline and post-remediation conditions. Various biomarkers of lead exposure can be employed, but their use requires detailed knowledge of what results using each means. The most commonly used approach is measurement of blood lead (Pb-B). Recognized limitations in the use of Pb-B has led to the use of predictive Pb exposure models, which are less vulnerable to the many behavioral, physiological, and environmental parameters that can distort isolated or 'single shot' Pb-B testings. A third aspect covered in this paper presents various physiological factors that affect the methods by which one evaluates Pb remediation effectiveness. Finally, this article offers an integrated look at how lead remediation actions directed at one lead source or pathway affect the total lead exposure picture for human populations at elevated lead exposure and toxicity risk.

Decompression Sickness After Air Break in Prebreathe Described with a Survival Model

NASA Technical Reports Server (NTRS)

Conkin, J.; Pilmanis, A. A.

2010-01-01

Data from Brooks City-Base show the decompression sickness (DCS) and venous gas emboli (VGE) consequences of air breaks in a resting 100% O2 prebreathe (PB) prior to a hypobaric exposure. METHODS: DCS and VGE survival times from 95 controls for a 60 min PB prior to 2-hr or 4-hr exposures to 4.37 psia are statistically compared to 3 break in PB conditions: a 10 min (n=40), 20 min (n=40), or 60 min break (n=32) 30 min into the PB followed by 30 min of PB. Ascent rate was 1,524 meters / min and all exposures included light exercise and 4 min of VGE monitoring of heart chambers at 16 min intervals. DCS survival time for combined control and air breaks were described with an accelerated log logistic model where exponential N2 washin during air break was described with a 10 min half-time and washout during PB with a 60 min half-time. RESULTS: There was no difference in VGE or DCS survival times among 3 different air breaks, or when air breaks were compared to control VGE times. However, 10, 20, and 60 min air breaks had significantly earlier survival times compared to control DCS times, certainly early in the exposures. CONCLUSION: Air breaks of 10, 20, and 60 min after 30 min of a 60 min PB reduced DCS survival time. The survival model combined discrete comparisons into a global description mechanistically linked to asymmetrical N2 washin and washout kinetics based on inspired pN2. Our unvalidated regression is used to compute additional PB time needed to compensate for an air break in PB within the range of tested conditions.

Investigation and health risk assessment of heavy metals in soils from partial areas of Daye city, china

NASA Astrophysics Data System (ADS)

Xiao, M. S.; Li, F.; Zhang, J. D.; Lin, S. Y.; Zhuang, Z. Y.; Wu, Z. X.

2017-05-01

Heavy metals (Cu and Pb) in four sampling sites from parts areas of Daye city were collected. Concentrations of Cu and Pb in soils in sampling sites were detected, the enrichment degree was measured by geo-accumulation index, and the human health risks were calculated by applying the human health risk assessment model. The results show that the concentrations of Cu and Pb of soils in some areas are much more than Daye City, Hubei Province soil background value. The concentration of Cu and Pb in Xiaganwan soil sample has a higher value and the concentration of Cu (110.17 mg·kg-1) exceeds the soil environmental quality standards. The values of Igeo of Cu and Pb in the soil in some areas of Daye city are 1 except Xiaganwan sample is 2. For human health risk assessment, the non-cancer risk of Cu in three routes of exposure is less than Pb. The non-cancer risk both adults and children are less than 1 and show a general trend of HQ in oral ingestion exposure pathway > HQ in inhalation exposure pathway>HQ in skin contact exposure pathway. It will not cause significant non-carcinogenic health effects on the human body.

Evolving from reactive to proactive medicine: community lead (Pb) and clinical disparities in pre- and post-Katrina New Orleans.

PubMed

Mielke, Howard W; Gonzales, Christopher; Powell, Eric; Mielke, Paul W

2014-07-21

In 2012 the U.S. Centers for Disease Control (CDC) set the blood Pb reference value at ≥5 µg/dL. Clinical analysis of children's blood Pb levels is the common way to diagnose environmental Pb contamination, and intervention ensues with education and household dust cleanup. Recent review indicates that education and household dust cleanup are not effective at reducing children's Pb exposure. Here we review mapping environmental Pb and children's blood Pb response as an alternative approach for proactive Pb dust intervention. New Orleans was divided into a high (≥100 mg/kg) and low (<100 mg/kg) soil Pb communities. The children's blood Pb prevalence ≥5 µg/dL for the high and low Pb domains were 58.5% and 24.8% respectively pre-Katrina vs. 29.6% and 7.5% post-Katrina. Elevated soil Pb (mg/kg) and consequently Pb loading (µg/square area) permeates the high Pb domain and outdoor locations lack Pb dust safe play areas. The U.S. EPA 400 mg/kg soil Pb standard poses an outside Pb dust loading burden >37 times larger than allowed on interior residential floor environments. Environmental Pb dust is decreasing because of the transfer of large quantities of low Pb soil into selected communities. City-scale soil Pb mapping is an alternative diagnostic tool that provides information for planning proactive medicine to prevent clinical Pb exposure in the first place.

Evolving from Reactive to Proactive Medicine: Community Lead (Pb) and Clinical Disparities in Pre- and Post-Katrina New Orleans

PubMed Central

Mielke, Howard W.; Gonzales, Christopher; Powell, Eric; Mielke, Paul W.

2014-01-01

In 2012 the U.S. Centers for Disease Control (CDC) set the blood Pb reference value at ≥5 µg/dL. Clinical analysis of children’s blood Pb levels is the common way to diagnose environmental Pb contamination, and intervention ensues with education and household dust cleanup. Recent review indicates that education and household dust cleanup are not effective at reducing children’s Pb exposure. Here we review mapping environmental Pb and children’s blood Pb response as an alternative approach for proactive Pb dust intervention. New Orleans was divided into a high (≥100 mg/kg) and low (<100 mg/kg) soil Pb communities. The children’s blood Pb prevalence ≥5 µg/dL for the high and low Pb domains were 58.5% and 24.8% respectively pre-Katrina vs. 29.6% and 7.5% post-Katrina. Elevated soil Pb (mg/kg) and consequently Pb loading (µg/square area) permeates the high Pb domain and outdoor locations lack Pb dust safe play areas. The U.S. EPA 400 mg/kg soil Pb standard poses an outside Pb dust loading burden >37 times larger than allowed on interior residential floor environments. Environmental Pb dust is decreasing because of the transfer of large quantities of low Pb soil into selected communities. City-scale soil Pb mapping is an alternative diagnostic tool that provides information for planning proactive medicine to prevent clinical Pb exposure in the first place. PMID:25050655

Evidence for Altered Hippocampal Volume and Brain Metabolites in Workers Occupationally Exposed to Lead: A Study by Magnetic Resonance Imaging and 1H Magnetic Resonance Spectroscopy

PubMed Central

Jiang, Yue-Ming; Long, Li-Ling; Zhu, Xia-Yan; Zheng, Hong; Fu, Xue; Ou, Shi-Yan; Wei, Dong-Lu; Zhou, Hai-Lin; Zheng, Wei

2008-01-01

Environmental and occupational exposure to lead (Pb) remains to be a major public health issue. The purpose of this cross-sectional study was to use non-invasive magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS) techniques to investigate whether chronic exposure to Pb in an occupational setting altered brain structure and function of Pb-exposed workers. The Pb-exposed group consisted of 15 workers recruited from either a Pb-smelting factory or a Pb-battery manufacturer. The control group had 19 healthy volunteers who had no history of Pb exposure in working environment or at home. The average airborne Pb concentrations in fume and dust were 0.43 mg/m3 and 0.44 mg/m3, respectively in the smeltery, and 0.10 mg/m3 and 1.06 mg/m3, respectively in the Pb battery workshop. The average blood Pb concentrations (BPb) in Pb-exposed and control workers were 63.5 µg/dL and 8.7 µg/dL, respectively. The MRI examination showed that brain hippocampal volume among Pb-exposed workers was significantly diminished in comparison to age-matched control subjects (p<0.01), although the extent of this reduction was relatively small (5–6% of the control values). Linear regression analyses revealed significant inverse associations between BPb and the decreased hippocampal volume on both sides of brain hemisphere. Among five brain metabolites investigated by MRS, i.e., N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho), inosine (mI), glutamate/glutamine (Glx) and lipids (Lip), a significant decrease in NAA/Cr ratio (7% of controls, p<0.05) and a remarkable increase in Lip/Cr ratio (40%, p<0.01) were observed in the brains of Pb-exposed workers as compared to controls. Furthermore, the increased Lip/Cr ratio was significantly associated with BPb (r = 0.46, p<0.01). Taken together, this study suggests that occupational exposure to Pb may cause subtle structural and functional alteration in human brains. The MRI and MRS brain imaging techniques can be used as the noninvasive means to evaluate Pb-induced neurotoxicity. PMID:18692119

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).

Toxic effects of lead on biochemical and histological alterations in green mussel (Perna viridis) induced by environmentally relevant concentrations.

PubMed

Hariharan, G; Purvaja, R; Ramesh, R

2014-01-01

Acute and chronic toxicity tests were conducted on green mussel (Perna viridis) to determine the adverse effects of lead (Pb). Exposure of organisms to acute toxicity test for 96 h and lethal concentration (LC(50)) was the endpoint of the test. Acute toxicity for 96-h LC(50) and 95% confidence intervals of P. viridis was 2.62 ± 0.12 (2.62-3.24) mg/L Pb. Chronic toxicity tests revealed that survival of exposed organisms decreased with elevated exposure concentrations. No-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) were calculated based on survival of test organisms. Results of this study demonstrated an increase in toxicity in test organisms with rise in exposure time and concentration. In this study, histology and biochemical enzymes, namely, catalase, reduced glutathione, glutathione S-transferase, and lipid peroxides, were correlated with chronic value and survival endpoints of P. viridis after chronic exposure to Pb. Biochemical and histological responses to different concentrations of Pb were assessed and significant differences were observed between control and increasing exposure concentrations. Biomarker studies in internal organs confirmed that the observed changes are due to adverse effects of Pb. This assessment of toxicity was the first step to determining the seawater quality criteria for marine organisms.

Does oral exposure to cadmium and lead mediate susceptibility to colitis? The dark-and-bright sides of heavy metals in gut ecology

NASA Astrophysics Data System (ADS)

Breton, Jérôme; Daniel, Catherine; Vignal, Cécile; Body-Malapel, Mathilde; Garat, Anne; Plé, Coline; Foligné, Benoît

2016-01-01

Although the heavy metals cadmium (Cd) and lead (Pb) are known environmental health concerns, their long-term impacts on gut ecology and susceptibility to gastrointestinal autoimmune diseases have not been extensively investigated. We sought to determine whether subchronic oral exposure to Cd or Pb is a risk factor for the development and progression of inflammatory bowel disease (IBD). Mice were exposed to various doses of CdCl2 or PbCl2 in drinking water for 1, 4 or 6 weeks prior to infection with Salmonella, the induction of colitis with dextran sodium sulfate (DSS) or trinitrobenzene sulfonic acid (TNBS). In human cell-based models, exposure to Cd and Pb is associated with reduced transepithelial electric resistance and changes in bacteria-induced cytokine responses. Although 1- and 6-week exposures did not have clear effects on the response to Salmonella infectious challenges, 1-week short-term treatments with CdCl2 tended to enhance intestinal inflammation in mice. Unexpectedly, subchronic exposure to Cd and (to a lesser extent) Pb significantly mitigated some of the symptoms of DSS-induced colitis and reduced the severity of TNBS colitis in a dose-dependent manner. The possible adaptive and immunosuppressive mechanisms by which heavy metals might reduce intestinal inflammation are explored and discussed.

Lead Exposure Assessment among Pregnant Women, Newborns, and Children: Case Study from Karachi, Pakistan.

PubMed

Fatmi, Zafar; Sahito, Ambreen; Ikegami, Akihiko; Mizuno, Atsuko; Cui, Xiaoyi; Mise, Nathan; Takagi, Mai; Kobayashi, Yayoi; Kayama, Fujio

2017-04-13

Lead (Pb) in petrol has been banned in developed countries. Despite the control of Pb in petrol since 2001, high levels were reported in the blood of pregnant women and children in Pakistan. However, the identification of sources of Pb has been elusive due to its pervasiveness. In this study, we assessed the lead intake of pregnant women and one- to three-year-old children from food, water, house dust, respirable dust, and soil. In addition, we completed the fingerprinting of the Pb isotopic ratios (LIR) of petrol and secondary sources (food, house-dust, respirable dust, soil, surma (eye cosmetics)) of exposure within the blood of pregnant women, newborns, and children. Eight families, with high (~50 μg/dL), medium (~20 μg/dL), and low blood levels (~10 μg/dL), were selected from 60 families. The main sources of exposure to lead for children were food and house-dust, and those for pregnant women were soil, respirable dust, and food. LIR was determined by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) with a two sigma uncertainty of ±0.03%. The LIR of mothers and newborns was similar. In contrast, surma , and to a larger extent petrol, exhibited a negligible contribution to both the child's and mother's blood Pb. Household wet-mopping could be effective in reducing Pb exposure. This intake assessment could be replicated for other developing countries to identify sources of lead and the burden of lead exposure in the population.

Childhood developmental vulnerabilities associated with early life exposure to infectious and noninfectious diseases and maternal mental illness.

PubMed

Green, Melissa J; Kariuki, Maina; Dean, Kimberlie; Laurens, Kristin R; Tzoumakis, Stacy; Harris, Felicity; Carr, Vaughan J

2017-12-26

Fetal exposure to infectious and noninfectious diseases may influence early childhood developmental functioning, on the path to later mental illness. Here, we investigated the effects of in utero exposure to maternal infection and noninfectious diseases during pregnancy on offspring developmental vulnerabilities at age 5 years, in the context of estimated effects for early childhood exposures to infectious and noninfectious diseases and maternal mental illness. We used population data for 66,045 children from an intergenerational record linkage study (the New South Wales Child Development Study), for whom a cross-sectional assessment of five developmental competencies (physical, social, emotional, cognitive, and communication) was obtained at school entry, using the Australian Early Development Census (AEDC). Child and maternal exposures to infectious or noninfectious diseases were determined from the NSW Ministry of Health Admitted Patients Data Collection (APDC) and maternal mental illness exposure was derived from both APDC and Mental Health Ambulatory Data collections. Multinomial logistic regression analyses were used to examine unadjusted and adjusted associations between these physical and mental health exposures and child developmental vulnerabilities at age 5 years. Among the physical disease exposures, maternal infectious diseases during pregnancy and early childhood infection conferred the largest associations with developmental vulnerabilities at age 5 years; maternal noninfectious illness during pregnancy also retained small but significant associations with developmental vulnerabilities even when adjusted for other physical and mental illness exposures and covariates known to be associated with early childhood development (e.g., child's sex, socioeconomic disadvantage, young maternal age, prenatal smoking). Among all exposures examined, maternal mental illness first diagnosed prior to childbirth conferred the greatest odds of developmental vulnerability at age 5 years. Prenatal exposure to infectious or noninfectious diseases appear to influence early childhood physical, social, emotional and cognitive developmental vulnerabilities that may represent intermediate phenotypes for subsequent mental disorders. © 2017 Association for Child and Adolescent Mental Health.

Case-Only Gene–Environment Interaction Between ALAD tagSNPs and Occupational Lead Exposure in Prostate Cancer

PubMed Central

Neslund-Dudas, Christine; Levin, Albert M.; Rundle, Andrew; Beebe-Dimmer, Jennifer; Bock, Cathryn H.; Nock, Nora L.; Jankowski, Michelle; Datta, Indrani; Krajenta, Richard; Dou, Q. Ping; Mitra, Bharati; Tang, Deliang; Rybicki, Benjamin A.

2014-01-01

BACKGROUND Black men have historically had higher blood lead levels than white men in the U.S. and have the highest incidence of prostate cancer in the world. Inorganic lead has been classified as a probable human carcinogen. Lead (Pb) inhibits delta-aminolevulinic acid dehydratase (ALAD), a gene recently implicated in other genitourinary cancers. The ALAD enzyme is involved in the second step of heme biosynthesis and is an endogenous inhibitor of the 26S proteasome, a master system for protein degradation and a current target of cancer therapy. METHODS Using a case-only study design, we assessed potential gene–environment (G × E) interactions between lifetime occupational Pb exposure and 11 tagSNPs within ALAD in black (N = 260) and white (N = 343) prostate cancer cases. RESULTS Two ALAD tagSNPs in high linkage disequilibrium showed significant interaction with high Pb exposure among black cases (rs818684 interaction odds ratio or IOR = 2.73, 95% CI 1.43–5.22, P = 0.002; rs818689 IOR = 2.20, 95% CI 1.15–4.21, P = 0.017) and an additional tagSNP, rs2761016, showed G × E interaction with low Pb exposure (IOR = 2.08, 95% CI 1.13– 3.84, P = 0.019). Further, the variant allele of rs818684 was associated with a higher Gleason grade in those with high Pb exposure among both blacks (OR 3.96, 95% CI 1.01–15.46, P = 0.048) and whites (OR 2.95, 95% CI 1.18–7.39, P = 0.020). CONCLUSIONS Genetic variation in ALAD may modify associations between Pb and prostate cancer. Additional studies of ALAD, Pb, and prostate cancer are warranted and should include black men. PMID:24500903

Lead and cadmium excretion in feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia.

PubMed

Yabe, John; Nakayama, Shouta M M; Ikenaka, Yoshinori; Yohannes, Yared B; Bortey-Sam, Nesta; Kabalo, Abel Nketani; Ntapisha, John; Mizukawa, Hazuki; Umemura, Takashi; Ishizuka, Mayumi

2018-07-01

Lead (Pb) and cadmium (Cd) are toxic metals that exist ubiquitously in the environment. Children in polluted areas are particularly vulnerable to metal exposure, where clinical signs and symptoms could be nonspecific. Absorbed metals are excreted primarily in urine and reflect exposure from all sources. We analyzed Pb and Cd concentrations in blood, feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia, to determine concurrent childhood exposure to the metals. Moreover, the study determined the Pb and Cd relationships among urine, feces and blood as well as accessed the potential of urine and fecal analysis for biomonitoring of Pb and Cd exposure in children. Fecal Pb (up to 2252 mg/kg, dry weight) and urine Pb (up to 2914 μg/L) were extremely high. Concentrations of Cd in blood (Cd-B) of up to 7.7 μg/L, fecal (up to 4.49 mg/kg, dry weight) and urine (up to 18.1 μg/L) samples were elevated. metal levels were higher in younger children (0-3 years old) than older children (4-7). Positive correlations were recorded for Pb and Cd among blood, urine and fecal samples whereas negative correlations were recorded with age. These findings indicate children are exposed to both metals at their current home environment. Moreover, urine and feces could be useful for biomonitoring of metals due to their strong relationships with blood levels. There is need to conduct a clinical evaluation of the affected children to fully appreciate the health impact of these metal exposure. Copyright © 2018. Published by Elsevier Ltd.

Co-exposure to lead increases the renal response to low levels of cadmium in metallurgy workers.

PubMed

Hambach, R; Lison, D; D'Haese, P C; Weyler, J; De Graef, E; De Schryver, A; Lamberts, L V; van Sprundel, M

2013-10-24

Research on the effect of co-exposure to Cd and Pb on the kidney is scarce. The objective of the present study was to assess the effect of co-exposure to these metals on biomarkers of early renal effect. Cd in blood (Cd-B), Cd in urine (Cd-U), Pb in blood (Pb-B) and urinary renal biomarkers, i.e., microalbumin (μ-Alb), beta-2-microglobulin (β₂-MG), retinol binding protein (RBP), N-acetyl-β-d-glucosaminidase (NAG), intestinal alkaline phosphatase (IAP) were measured in 122 metallurgic refinery workers examined in a cross-sectional survey. The median Cd-B, Cd-U, Pb-B were: 0.8 μg/l (IQR = 0.5, 1.2), 0.5 μg/g creatinine (IQR = 0.3, 0.8) and 158.5 μg/l (IQR = 111.0, 219.3), respectively. The impact of Cd-B on the urinary excretion of NAG and IAP was only evident among workers with Pb-B concentrations ≥ 75th percentile. The association between Cd-U and the renal markers NAG and RBP was also evidenced when Pb-B ≥ 75th percentile. No statistically significant interaction terms were observed for the associations between Cd-B or Cd-U and the other renal markers under study (i.e., μ-Alb and β2-MG). Our findings indicate that Pb increases the impact of Cd exposure on early renal biomarkers. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

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

Ema, Makoto, E-mail: ema-makoto@aist.go.jp; Gamo, Masashi; Honda, Kazumasa

We summarized significant effects reported in the literature on the developmental toxicity of engineered nanomaterials (ENMs) in rodents. The developmental toxicity of ENMs included not only structural abnormalities, but also death, growth retardation, and behavioral and functional abnormalities. Most studies were performed on mice using an injection route of exposure. Teratogenic effects were indicated when multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), and TiO{sub 2}-nanoparticles were administered to mice during early gestation. Reactive oxygen species levels were increased in placentas and malformed fetuses and their placentas after prenatal exposure to MWCNTs and SWCNTs, respectively. The pre- and postnatal mortalitiesmore » and growth retardation in offspring increased after prenatal exposure to ENMs. Histopathological and functional abnormalities were also induced in placentas after prenatal exposure to ENMs. Maternal exposure to ENMs induced behavioral alterations, histopathological and biochemical changes in the central nervous system, increased susceptibility to allergy, transplacental genotoxicity, and vascular, immunological, and reproductive effects in offspring. The size- and developmental stage-dependent placental transfer of ENMs was noted after maternal exposure. Silver accumulated in the visceral yolk sac after being injected with Ag-NPs during early gestation. Although currently available data has provided initial information on the potential developmental toxicity of ENMs, that on the developmental toxicity of ENMs is still very limited. Further studies using well-characterized ENMs, state-of the-art study protocols, and appropriate routes of exposure are required in order to clarify these developmental effects and provide information suitable for risk assessments of ENMs. - Highlights: • We review the developmental toxicity studies of engineered nanomaterials (ENMs). • Various developmental endpoints have been reported after exposure to ENMs. • Physico-chemical properties of ENMs are determinants of the developmental toxicity. • Oxidative stress/inflammation may be involved in the developmental toxicity of ENMs. • Further developmental toxicity studies of ENMs are needed to fill a data gap.« less

Meta-Analysis of Lead (Pb) in Multiple Environmental Media in the United States

EPA Science Inventory

Introduction: The U.S. Environmental Protection Agency, Office of Research and Development, conducts probabilistic multimedia lead (Pb) exposure modeling to inform the development of health-based benchmarks for Pb in the environment. For this modeling, robust Pb concentration dat...

Lead Sampling Protocols: Why So Many and What Do They Tell You?

EPA Science Inventory

Sampling protocols can be broadly categorized based on their intended purpose of 1) Pb regulatory compliance/corrosion control efficacy, 2) Pb plumbing source determination or Pb type identification, and 3) Pb exposure assessment. Choosing the appropriate protocol is crucial to p...

Dysfunction of cortical synapse-specific mitochondria in developing rats exposed to lead and its amelioration by ascorbate supplementation.

PubMed

Ahmad, Faraz; Salahuddin, Mohammad; Alamoudi, Widyan; Acharya, Sadananda

2018-01-01

Lead (Pb) is a widespread environmental neurotoxin and its exposure even in minute quantities can lead to compromised neuronal functions. A developing brain is particularly vulnerable to Pb mediated toxicity and early-life exposure leads to permanent alterations in brain development and neuronal signaling and plasticity, culminating into cognitive and behavioral dysfunctions and elevated risk of neuropsychiatric disorders later in life. Nevertheless, the underlying biochemical mechanisms have not been completely discerned. Because of their ability to fulfill high energy needs and to act as calcium buffers in events of high intensity neuronal activity as well as their adaptive regulatory capability to match the requirements of the dynamicity of synaptic signaling, synapse-specific or synaptic mitochondria (SM) are critical for synaptic development, function and plasticity. Our aim for the present study hence was to characterize the effects of early-life Pb exposure on the functions of SM of prepubertal rats. For this purpose, employing a chronic model of Pb neurotoxicity, we exposed rat pups perinatally and postnatally to Pb and used a plethora of colorimetric and fluorometric assays for assessing redox and bioenergetic properties of SM. In addition, taking advantage of its ability as an antioxidant and as a metal chelator, we employed ascorbic acid (vitamin C) supplementation as an ameliorative therapeutic strategy against Pb-induced neurotoxicity and dysfunction of SM. Our results suggest that early-life exposure to Pb leads to elevated oxidative stress in cortical SM with consequent compromises in its energy metabolism activity. Ascorbate supplementation resulted in significant recovery of Pb-induced oxidative stress and functional compromise of SM. Alterations in redox status and bioenergetic properties of SM could potentially contribute to the synaptic dysfunction observed in events of Pb neurotoxicity. Additionally, our study provides evidence for suitability of ascorbate as a significant ameliorative agent in tacking Pb neurotoxicity.

Relative importance of different exposure routes of heavy metals for humans living near a municipal solid waste incinerator.

PubMed

Li, Tong; Wan, Yi; Ben, Yujie; Fan, Senrong; Hu, Jianying

2017-07-01

The potential health effects of toxic chemicals (e.g. heavy metals) emitted by municipal solid waste incinerators (MSWIs) are of great concern to local residents, however there have been few studies on the contributions of different exposure pathways and their subsequent effects on the body burden of residents living near MSWIs. In this study, multiple exposure routes of heavy metals including Pb, Cr, Cd and Mn were assessed by investigating the metals in foods (such as vegetables, crops, meats and fruits etc.), drinking water, ambient air and soil collected surrounding an MSWI in Shenzhen, south China. Vegetable ingestion played the most important role in the total average daily dose of Pb and Cr, and cereals were the key exposure routes for Mn and Cd. Compound-specific contaminations were observed in the investigated areas, with Pb and Cr present in the surrounding environment, having accumulated to relatively high levels in the local vegetables, and the intake of contaminated vegetable foods greatly influencing the body burden of Pb and Cr. Consistently, significantly high blood concentrations of Pb and Cr were detected in the local residents compared to a referenced population, and a lack of significant differences was found for Cd and Mn. The results possibly suggested that emission of MSWI influenced the external exposure doses of the major pathways of Pb and Cr in this study, and resulted in the different body burden of metals in humans living near a MSWI. MSWI-local food-humans is an important exposure pathway for residents living near MSWI, and thus should not be neglected in developing future strategies and policies to prevent the high risks suffered by residents living near MSWIs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phenobarbital induces cell cycle transcriptional responses in mouse liver humanized for constitutive androstane and pregnane x receptors.

PubMed

Luisier, Raphaëlle; Lempiäinen, Harri; Scherbichler, Nina; Braeuning, Albert; Geissler, Miriam; Dubost, Valerie; Müller, Arne; Scheer, Nico; Chibout, Salah-Dine; Hara, Hisanori; Picard, Frank; Theil, Diethilde; Couttet, Philippe; Vitobello, Antonio; Grenet, Olivier; Grasl-Kraupp, Bettina; Ellinger-Ziegelbauer, Heidrun; Thomson, John P; Meehan, Richard R; Elcombe, Clifford R; Henderson, Colin J; Wolf, C Roland; Schwarz, Michael; Moulin, Pierre; Terranova, Rémi; Moggs, Jonathan G

2014-06-01

The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are closely related nuclear receptors involved in drug metabolism and play important roles in the mechanism of phenobarbital (PB)-induced rodent nongenotoxic hepatocarcinogenesis. Here, we have used a humanized CAR/PXR mouse model to examine potential species differences in receptor-dependent mechanisms underlying liver tissue molecular responses to PB. Early and late transcriptomic responses to sustained PB exposure were investigated in liver tissue from double knock-out CAR and PXR (CAR(KO)-PXR(KO)), double humanized CAR and PXR (CAR(h)-PXR(h)), and wild-type C57BL/6 mice. Wild-type and CAR(h)-PXR(h) mouse livers exhibited temporally and quantitatively similar transcriptional responses during 91 days of PB exposure including the sustained induction of the xenobiotic response gene Cyp2b10, the Wnt signaling inhibitor Wisp1, and noncoding RNA biomarkers from the Dlk1-Dio3 locus. Transient induction of DNA replication (Hells, Mcm6, and Esco2) and mitotic genes (Ccnb2, Cdc20, and Cdk1) and the proliferation-related nuclear antigen Mki67 were observed with peak expression occurring between 1 and 7 days PB exposure. All these transcriptional responses were absent in CAR(KO)-PXR(KO) mouse livers and largely reversible in wild-type and CAR(h)-PXR(h) mouse livers following 91 days of PB exposure and a subsequent 4-week recovery period. Furthermore, PB-mediated upregulation of the noncoding RNA Meg3, which has recently been associated with cellular pluripotency, exhibited a similar dose response and perivenous hepatocyte-specific localization in both wild-type and CAR(h)-PXR(h) mice. Thus, mouse livers coexpressing human CAR and PXR support both the xenobiotic metabolizing and the proliferative transcriptional responses following exposure to PB.

[Lead exposure in the ceramic tile industry: time trends and current exposure levels].

PubMed

Candela, S; Ferri, F; Olmi, M

1998-01-01

There is a high density of industries for the production of ceramic tiles in the District of Scandiano (province of Reggio Emilia, Emilia Romagna region). In this area, since the beginning of 1970s, the time trend of Pb exposure in ceramic tile plants has been evaluated by means of biological monitoring (BM) data collected at the Service of Prevention and Safety in the Work Environment and its associated Toxicology Laboratory. From these data, a clear decreasing time trend of exposure levels is documented, the reduction being more evident during the seventies and in 1985-88. During the seventies BM was introduced systematically in all ceramic tile plants with the determination of delta-aminolevulinic acid in urine (ALA-U). As a consequence of the BM programme, hygienic measures for the abatement of pollution inside the plants were implemented, and a reduction, from 20.6% to 2%, of ALA-U values exceeding 10 mg/l, was observed. In 1985, the determination of lead in blood (PbB) replaced that of ALA-U in the BM programmes and highlighted the persistence of high level of exposure to Pb, which could not be outlined by means of ALA-U because of its lower sensitivity. PbB levels were 36.1 micrograms/100 ml and 25.7 micrograms/100 ml in male and female workers, respectively. These results required the implementation, within the plants, of additional hygienic measures and a significant reduction of PbB was obtained in the following three years. In 1988 PbB levels were 26.0 +/- 10.7 and 21.6 +/- 10.3 micrograms/100 ml in male and female workers, respectively. In 1993-95 Pb levels were obtained from 1328 male and 771 female workers of 56 plants, accounting for about 40% of the total number of workers in the ceramic industry, in the zones of Sassuolo and Scandiano. Exposure levels are not different from those observed in the preceding years, with PbB levels of 25.3 +/- 11.1 and 19.1 +/- 9.2 micrograms/100 ml in male and female workers, respectively.

The developmental neurotoxicity of arsenic: cognitive and behavioral consequences of early life exposure.

PubMed

Tolins, Molly; Ruchirawat, Mathuros; Landrigan, Philip

2014-01-01

More than 200 million people worldwide are chronically exposed to arsenic. Arsenic is a known human carcinogen, and its carcinogenic and systemic toxicity have been extensively studied. By contrast, the developmental neurotoxicity of arsenic has been less well described. The aim of this review was to provide a comprehensive review of the developmental neurotoxicity of arsenic. We reviewed the published epidemiological and toxicological literature on the developmental neurotoxicity of arsenic. Arsenic is able to gain access to the developing brain and cause neurotoxic effects. Animal models link prenatal and early postnatal exposure to reduction in brain weight, reductions in numbers of glia and neurons, and alterations in neurotransmitter systems. Animal and in vitro studies both suggest that oxidative stress may be a mechanism of arsenic neurotoxicity. Fifteen epidemiological studies indicate that early life exposure is associated with deficits in intelligence and memory. These effects may occur at levels of exposure below current safety guidelines, and some neurocognitive consequences may become manifest only later in life. Sex, concomitant exposures, and timing of exposure appear to modify the developmental neurotoxicity of arsenic. Four epidemiological studies failed to show behavioral outcomes of arsenic exposure. The published literature indicates that arsenic is a human developmental neurotoxicant. Ongoing and future prospective birth cohort studies will allow more precise definition of the developmental consequences of arsenic exposure in early life. Copyright © 2014. Published by Elsevier Inc.

Brevetoxin exposure in sea turtles in south Texas (USA) during Karenia brevis red tide.

PubMed

Walker, Jennifer Shelby; Shaver, Donna J; Stacy, Brian A; Flewelling, Leanne J; Broadwater, Margaret H; Wang, Zhihong

2018-01-31

Five green (Chelonia mydas) and 11 Kemp's ridley (Lepidochelys kempii) sea turtles found dead, or that died soon after stranding, on the southern Texas (USA) coast during 2 Karenia brevis blooms (October 2015, September-October 2016) were tested for exposure to brevetoxins (PbTx). Tissues (liver, kidney) and digesta (stomach and intestinal contents) were analyzed by ELISA. Three green turtles found alive during the 2015 event and 2 Kemp's ridley turtles found alive during the 2016 event exhibited signs of PbTx exposure, including lethargy and/or convulsions of the head and neck. PbTx were detected in 1 or more tissues or digesta in all 16 stranded turtles. Detected PbTx concentrations ranged from 2 to >2000 ng g-1. Necropsy examination and results of PbTx analysis indicated that 10 of the Kemp's ridleys and 2 of the green turtles died from brevetoxicosis via ingestion. This is the first documentation of sea turtle mortality in Texas attributed to brevetoxicosis.

Characterization of marine aerosol for assessment of human exposure to brevetoxins.

PubMed

Cheng, Yung Sung; Zhou, Yue; Irvin, Clinton M; Pierce, Richard H; Naar, Jerome; Backer, Lorraine C; Fleming, Lora E; Kirkpatrick, Barbara; Baden, Dan G

2005-05-01

Red tides in the Gulf of Mexico are commonly formed by the fish-killing dinoflagellate Karenia brevis, which produces nine potent polyether brevetoxins (PbTxs). Brevetoxins can be transferred from water to air in wind-powered white-capped waves. Inhalation exposure to marine aerosol containing brevetoxins causes respiratory symptoms. We describe detailed characterization of aerosols during an epidemiologic study of occupational exposure to Florida red tide aerosol in terms of its concentration, toxin profile, and particle size distribution. This information is essential in understanding its source, assessing exposure to people, and estimating dose of inhaled aerosols. Environmental sampling confirmed the presence of brevetoxins in water and air during a red tide exposure period (September 2001) and lack of significant toxin levels in the water and air during an unexposed period (May 2002). Water samples collected during a red tide bloom in 2001 showed moderate-to-high concentrations of K. brevis cells and PbTxs. The daily mean PbTx concentration in water samples ranged from 8 to 28 microg/L from 7 to 11 September 2001; the daily mean PbTx concentration in air samples ranged from 1.3 to 27 ng/m(3). The daily aerosol concentration on the beach can be related to PbTx concentration in water, wind speed, and wind direction. Personal samples confirmed human exposure to red tide aerosols. The particle size distribution showed a mean aerodynamic diameter in the size range of 6-12 microm, with deposits mainly in the upper airways. The deposition pattern correlated with the observed increase of upper airway symptoms in healthy lifeguards during the exposure periods.

Effects of low-level prenatal lead exposure on child IQ at 4 and 8 years in a UK birth cohort study.

PubMed

Taylor, Caroline M; Kordas, Katarzyna; Golding, Jean; Emond, Alan M

2017-09-01

The association between childhood exposure to lead (Pb) and deficits in cognitive function is well established. The association with prenatal exposure, however, is not well understood, even though the potential adverse effects are equally important. To evaluate the association between low prenatal exposure to lead and IQ in children, to determine whether there were sex differences in the associations, and to evaluate the moderation effect of prenatal Pb exposure on child IQ. Whole blood samples from pregnant women enrolled in ALSPAC (n=4285) and from offspring at age 30 months (n=235) were analysed for Pb. Associations between prenatal blood lead concentrations (B-Pb) and child IQ at age 4 and 8 years (WPPSI and WISC-III, respectively) were examined in adjusted regression models. There was no association of prenatal lead exposure with child IQ at 4 or 8 years old in adjusted regression models, and no moderation of the association between child B-Pb and IQ. However, there was a positive association for IQ at age 8 years in girls with a predicted increase in IQ (points) per 1μg/dl of: verbal 0.71, performance 0.57, total 0.73. In boys, the coefficients tended to be negative (-0.15, -0.42 and -0.29 points, respectively). Prenatal lead exposure was not associated with adverse effects on child IQ at age 4 or 8 years in this study. There was, however, some evidence to suggest that boys are more susceptible than girls to prenatal exposure to lead. Further investigation in other cohorts is required. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of selenium-lead interaction on the gene expression of inflammatory factors and selenoproteins in chicken neutrophils.

PubMed

Li, Xiaojing; Xing, Mengyuan; Chen, Menghao; Zhao, Jinxin; Fan, Ruifeng; Zhao, Xia; Cao, Changyu; Yang, Jie; Zhang, Ziwei; Xu, Shiwen

2017-05-01

Lead (Pb) is one of the most highly toxic metal pollutant that can cause damage to the immune system. It is known that selenium (Se) can antagonize heavy metals. To explore the toxic effects of Pb poisoning on bird immune cells, as well as the alleviating effects of Se on Pb, Se supplement and/or Pb poisoning chicken models were established. One hundred and eighty Hyline 7-day-old male chickens received either Se (1mg Se per kg of diet), Pb (350mg Pb per liter water) or Se+Pb in their diet and water for 90 days. Then, whole blood was collected from the four groups of chickens, and serum and neutrophils were isolated. The levels of Se and Pb in chicken serum, mRNA levels of 24 selenoproteins (GPX1, GPX2, GPX3, GPX4, Dio1, Dio2, Dio3, Txnrd1, Txnrd2, Txnrd3, SELS, SPS2, SELK, SELW1, SEP15, SEPX1, SELT, SELI, SELO, SELM, SEPN1, SEPP1, SELU, SELH) and inflammatory factors (TNF-α, COX-2, iNOS, NF-κB), and iNOS protein level in chicken neutrophils were determined, and protein-protein interaction prediction and principal component analysis were performed. The data showed that Pb exposure increased Pb content in serum, activated the NF-κB pathway, and increased the expression of selenoproteins in chicken neutrophils. Se supplements could reduce Pb concentration in serum, had a mitigative effect on the activation of the NF-κB pathway and further enhanced the upward trend of selenoprotein expression induced by Pb exposure. These results suggest that Se supplement could eliminate Pb in serum and alleviate the activation of the NF-κB pathway under Pb exposure by increasing the expression of selenoproteins. Copyright © 2017 Elsevier Inc. All rights reserved.

Declining blood lead and zinc protoporphyrin levels in Ecuadorian Andean children.

PubMed

Ortega, Fernando; Counter, S Allen; Buchanan, Leo H; Coronel Parra, Angelica M; Collaguaso, Maria Angela; Jacobs, Anthony B; Rifai, Nader; Hoover, Patricia Nolan

2013-09-01

To investigate current lead (Pb) exposure in children living in Andean Ecuadorian communities. Blood Pb (PbB) and zinc protoporphyrin (ZPP) levels were used respectively as biomarkers of acute and chronic Pb poisoning. The current PbB-ZPP levels were compared with previous pediatric PbB-ZPP levels recorded over years in the study area. Samples of whole blood were collected from 22 Andean children of Quechua and Mestizo backgrounds and measured for PbB concentrations by graphite furnace atomic absorption spectroscopy. ZPP/heme ratio and ZPP whole blood (ZPP WB) levels were measured with a hematofluorometer. The mean PbB level for children in the current study group was 14.5 μg/dL, which was significantly lower than the mean PbB level of 41.1 μg/dL found in the same study area in the 1996-2000 test period, and lower than the 22.2 μg/dL mean level found in the 2003-2007 period. The current mean ZPP/heme ratio was 102.1 μmol/mol, and the mean ZPP WB level was 46.3 μg/dL, both lower than values previously found in children in the study area. While the current pediatric PbB-ZPP levels in the study area remain elevated in some children, the overall levels indicate a decline relative to levels observed in the same Pb-contaminated area in the period between 1996 and 2007. The elevated ZPP levels suggest a history of chronic Pb exposure, and potential iron deficiency in some children. The overall reduction in PbB-ZPP levels suggests a positive outcome of a Pb-exposure education and prevention program, and the therapeutic intervention of succimer chelation therapy. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Early-life metal exposure and schizophrenia: A proof-of-concept study using novel tooth-matrix biomarkers.

PubMed

Modabbernia, A; Velthorst, E; Gennings, C; De Haan, L; Austin, C; Sutterland, A; Mollon, J; Frangou, S; Wright, R; Arora, M; Reichenberg, A

2016-08-01

Despite evidence for the effects of metals on neurodevelopment, the long-term effects on mental health remain unclear due to methodological limitations. Our objective was to determine the feasibility of studying metal exposure during critical neurodevelopmental periods and to explore the association between early-life metal exposure and adult schizophrenia. We analyzed childhood-shed teeth from nine individuals with schizophrenia and five healthy controls. We investigated the association between exposure to lead (Pb(2+)), manganese (Mn(2+)), cadmium (Cd(2+)), copper (Cu(2+)), magnesium (Mg(2+)), and zinc (Zn(2+)), and schizophrenia, psychotic experiences, and intelligence quotient (IQ). We reconstructed the dose and timing of early-life metal exposures using laser ablation inductively coupled plasma mass spectrometry. We found higher early-life Pb(2+) exposure among patients with schizophrenia than controls. The differences in log Mn(2+) and log Cu(2+) changed relatively linearly over time to postnatal negative values. There was a positive correlation between early-life Pb(2+) levels and psychotic experiences in adulthood. Moreover, we found a negative correlation between Pb(2+) levels and adult IQ. In our proof-of-concept study, using tooth-matrix biomarker that provides direct measurement of exposure in the fetus and newborn, we provide support for the role of metal exposure during critical neurodevelopmental periods in psychosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Genome-wide gene by lead exposure interaction analysis identifies UNC5D as a candidate gene for neurodevelopment.

PubMed

Wang, Zhaoxi; Claus Henn, Birgit; Wang, Chaolong; Wei, Yongyue; Su, Li; Sun, Ryan; Chen, Han; Wagner, Peter J; Lu, Quan; Lin, Xihong; Wright, Robert; Bellinger, David; Kile, Molly; Mazumdar, Maitreyi; Tellez-Rojo, Martha Maria; Schnaas, Lourdes; Christiani, David C

2017-07-28

Neurodevelopment is a complex process involving both genetic and environmental factors. Prenatal exposure to lead (Pb) has been associated with lower performance on neurodevelopmental tests. Adverse neurodevelopmental outcomes are more frequent and/or more severe when toxic exposures interact with genetic susceptibility. To explore possible loci associated with increased susceptibility to prenatal Pb exposure, we performed a genome-wide gene-environment interaction study (GWIS) in young children from Mexico (n = 390) and Bangladesh (n = 497). Prenatal Pb exposure was estimated by cord blood Pb concentration. Neurodevelopment was assessed using the Bayley Scales of Infant Development. We identified a locus on chromosome 8, containing UNC5D, and demonstrated evidence of its genome-wide significance with mental composite scores (rs9642758, p meta  = 4.35 × 10 -6 ). Within this locus, the joint effects of two independent single nucleotide polymorphisms (SNPs, rs9642758 and rs10503970) had a p-value of 4.38 × 10 -9 for mental composite scores. Correlating GWIS results with in vitro transcriptomic profiles identified one common gene, SLC1A5, which is involved in synaptic function, neuronal development, and excitotoxicity. Further analysis revealed interconnected interactions that formed a large network of 52 genes enriched with oxidative stress genes and neurodevelopmental genes. Our findings suggest that certain genetic polymorphisms within/near genes relevant to neurodevelopment might modify the toxic effects of Pb exposure via oxidative stress.

Biomonitoring brevetoxin exposure in mammals using blood collection cards.

PubMed Central

Fairey, E R; Shuart, N G; Busman, M; Moeller, P D; Ramsdell, J S

2001-01-01

A method has been tested in laboratory mice to monitor for the presence of brevetoxins in blood after exposure. The use of blood collection cards is an adaptation of a method employed for routine diagnostic and genetic testing of newborns. Blood is collected and applied to a 0.5-inch diameter circle on a specially prepared blood collection card and allowed to dry. The blood spots are then extracted and the presence of toxin activity is first screened using a high throughput receptor binding assay. Positive samples are then examined for specific brevetoxin congeners by liquid chromatography-tandem mass spectrometry. Preliminary experiments tested the efficiency and linearity of toxin extraction from blood spiked with brevetoxin-3 (PbTx-3). Blood from treated mice was tested for the presence of brevetoxin at different times following exposure to a sublethal dose (180 microg/kg PbTx-3). Brevetoxin activity determined by receptor assay increased to 25 +/- 7.4 nM PbTx-3 equivalents within 4 hr after exposure and was still detectable in three of four animals 24 hr after exposure. Tandem mass spectrometry provided confirmation of PbTx-3, which also increased for the time points between 0.5 and 4.0 hr exposure. However, PbTx-3 was not detected at 24 hr, which suggested the formation of a biologically active metabolite. We anticipate that this approach will provide a method to biomonitor brevetoxins in living marine resources (e.g., finfish), protected species, and humans. PMID:11485871

Efficacy of the chelating agent CaEDTA in reversing lead-induced changes in behavior.

PubMed

Cory-Slechta, D A; Weiss, B

1989-01-01

The chelating agent CaEDTA has been reported to reverse the deficits in intellectual function and performance associated with Pb (lead) exposure in children. However, such studies have not included rigorous controls for the intervention procedures per se. The experiments reported here examined reversibility of performance changes in a rat model based on behavior sensitive to low-level Pb exposure. Rats were exposed to 50 ppm sodium or Pb acetate in drinking water from weaning. Performance maintained under a Fixed-Interval schedule of food reinforcement began at 55 days of age. Following the onset of the characteristic increase in short interresponse times (IRTs) associated with low-level Pb exposure after 35 experimental sessions, Pb treatment was terminated. Animals within both the control and Pb groups were then matched on the basis of performance indices and injected daily for 5 days with either saline, 75 mg/kg or 150 mg/kg CaEDTA. Subsequent changes in F1 performance were monitored for 35-60 sessions. No consistent effects of CaEDTA were detected in control animals. CaEDTA treatment failed to reverse the behavioral effects in Pb-exposed animals. If anything, it tended to further increase the proportion of short IRTs. These data suggest that better controlled clinical studies are warranted to evaluate the efficacy of CaEDTA in reversing Pb-induced behavioral effects before its application for these purposes becomes widespread.

Alteration in plasma corticosterone levels following long term oral administration of lead produces depression like symptoms in rats.

PubMed

Haider, Saida; Saleem, Sadia; Tabassum, Saiqa; Khaliq, Saima; Shamim, Saima; Batool, Zehra; Parveen, Tahira; Inam, Qurat-ul-ain; Haleem, Darakhshan J

2013-03-01

Lead toxicity is known to induce a broad range of physiological, biochemical and behavioral dysfunctions that may result in adverse effects on several organs, including the central nervous system. Long-term exposure to low levels of lead (Pb(2+)) has been shown to produce behavioral deficits in rodents and humans by affecting hypothalamic-pituitary-adrenal (HPA) axis. These deficits are thought to be associated with altered brain monoamine neurotransmission and due to changes in glucocorticoids levels. This study was designed to investigate the effects of Pb(2+)exposure on growth rate, locomotor activity, anxiety, depression, plasma corticosterone and brain serotonin (5-HT) levels in rats. Rats were exposed to lead in drinking water (500 ppm; lead acetate) for 5 weeks. The assessment of depression was done using the forced swimming test (FST). Estimation of brain 5-HT was determined by high-performance liquid chromatography with electrochemical detection. Plasma corticosterone was determined by spectrofluorimetric method. The present study showed that long term exposure to Pb(2+) significantly decreased the food intake followed by the decrease in growth rate in Pb(2+)exposed rats as compared to control group. No significant changes in open field activity were observed following Pb(2+)exposure while significant increase in anxiogenic effect was observed. Increased plasma corticosterone and decreased 5-HT levels were exhibited by Pb(2+)exposed rats as compared to controls. A significant increase in depressive like symptoms was exhibited by Pb(2+)exposed rats as compared to control rats. The results are discussed in the context of Pb(2+) inducing a stress-like response in rats leading to changes in plasma corticosterone and brain 5-HT levels via altering tryptophan pyrrolase activity.

Adverse health effects of lead exposure on children and exploration to internal lead indicator.

PubMed

Wang, Q; Zhao, H H; Chen, J W; Gu, K D; Zhang, Y Z; Zhu, Y X; Zhou, Y K; Ye, L X

2009-11-15

Our research on adverse effects of lead exposures on physical and neurobehavioral health of children aged 6-12years in 4 villages, labeled as K, M, L, and X, in rural China, was reported in this article. Lead in blood (PbB), urine (PbU), hairs (PbH), and nails (PbN) were measured by graphite furnace atomic absorption spectrometry. Abbreviated Symptom Questionnaire of Conner's instruments and Revised Raven's Standard Progressive Matrices were applied to evaluate childhood attention deficit/hyperactivity disorders (ADHD) and intelligences. Geometric means (SD) of PbB, PbU, PbH and PbN concentrations were 71.2 microg/L (1.56), 11.7 microg/g (1.75), 12.5 microg/g (2.82), and 25.3 microg/g (2.79), respectively. 54 (17.0%) children had PbB levels of > or =100 microg/L. Boys, 6-10 years old, and living in village K were 2.11, 2.48, and 9.16 times, respectively, more likely to be poisoned by lead than girls, aged 11-12 years, and residing in X. 18 (5.7%) and 37 (11.7%) subjects had ADHD and mental retardations, respectively. Inverse relationships between intelligences and natural log transformed PbU and PbH levels were observed with respective odds ratios (95%CI) of 1.79 (1.00-3.22) and 1.46 (1.06-2.03) or 1.28 (1.04-1.58) and 1.73 (1.18-2.52) by binary or ordinal logistic regression modeling. ADHD prevalence was different by gender and age of subjects. PbU, PbH, and PbN related to PbB positively with respective correlation coefficients of 0.530, 0.477, and 0.181. Receiver operating characteristic (ROC) curves of the three measurements revealed areas under curves (AUCs) being 0.829, 0.758, and 0.687, respectively. In conclusion, children had moderate levels of lead exposures in this rural area. Intelligence declines were associated with internal lead levels among children. ROC analysis suggests PbU an internal lead indicator close to PbB.

Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure

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

Barbosa, Fernando; Ramires, Irene; Rodrigues, Maria Heloisa C.

2006-09-15

We examined the effect of age and sex on the relationship between the concentrations of Pb in blood (Pb-B) and in plasma (Pb-P) in an adult population with a history of lead exposure. Pb-P was determined by inductively coupled plasma mass spectrometry (ICP-MS) and Pb-B by graphite furnace atomic absorption spectrometry (GF AAS). We studied 154 adults (56 men and 98 women) from 18 to 60-year old. Pb-B levels varied from 10.0 to 428.0 {mu}g/L, with a mean of 76 {mu}g/L. Blood lead levels varied from 10.0 to 428.0 {mu}g/L in men (mean, 98.3 {mu}g/L) and from 10.0 to 263.0more » {mu}g/L (mean, 62.8 {mu}g/L) in women. Corresponding Pb-Ps were 0.02-2.9 {mu}g/L (mean, 0.66 {mu}g/L) and 0.02-1.5 {mu}g/L (mean, 0.42 {mu}g/L) in men and women, respectively. The relationship between Pb-B and Pb-P was found to be curvilinear (r=0.757, P<0.001 Spearman's correlation). The two quantities are related by the line y=0.0006x {sup 1492} (y=Pb-P, and x=Pb-B). The %Pb-P/Pb-B ratio ranged from 0.03% to 1.85%. A positive association was found between %Pb-P/Pb-B ratio and Pb-B levels. When data were separated by sex, this association was also relevant for men (y=0.0184x {sup 0.702}) and women (y=0.0534x {sup 0.5209}) (y=%Pb-P/Pb-B and x=Pb-B). Moreover, we found an interesting positive correlation between Log (Pb-P/Pb-B) and age for women (r=0.31, P<0.0001) and a negative correlation for men (r=-0.164, P=0.07). Taken together, these results suggest contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. Moreover, sex might play an important role in the metabolism of lead, implying further consideration on the kinetic models constructed of lead toxicity.« less

Growth in Inuit children exposed to polychlorinated biphenyls and lead during fetal development and childhood.

PubMed

Dallaire, Renée; Dewailly, Éric; Ayotte, Pierre; Forget-Dubois, Nadine; Jacobson, Sandra W; Jacobson, Joseph L; Muckle, Gina

2014-10-01

Because of their geographical location and traditional lifestyle, Canadian Inuit children are highly exposed to polychlorinated biphenyls (PCBs) and lead (Pb), environmental contaminants that are thought to affect fetal and child growth. We examined the associations of these exposures with the fetal and postnatal growth of Inuit children. We conducted a prospective cohort study among Inuit from Nunavik (Arctic Québec). Mothers were recruited at their first prenatal visit; children (n=290) were evaluated at birth and at 8-14 years of age. Concentrations of PCB 153 and Pb were determined in umbilical cord and child blood. Weight, height and head circumference were measured at birth and during childhood. Cord blood PCB 153 concentrations were not associated with anthropometric measurements at birth or school age, but child blood PCB 153 concentrations were associated with reduced weight, height and head circumference during childhood. There was no association between cord Pb levels and anthropometric outcomes at birth, but cord blood Pb was related to smaller height and shows a tendency of a smaller head circumference during childhood. Our results suggest that chronic exposure to PCBs during childhood is negatively associated with skeletal growth and weight, while prenatal Pb exposure is related to reduced growth during childhood. This study is the first to link prenatal Pb exposure to poorer growth in school-age children. Copyright © 2014 Elsevier Inc. All rights reserved.

Lead Exposure Assessment among Pregnant Women, Newborns, and Children: Case Study from Karachi, Pakistan

PubMed Central

Fatmi, Zafar; Sahito, Ambreen; Ikegami, Akihiko; Mizuno, Atsuko; Cui, Xiaoyi; Mise, Nathan; Takagi, Mai; Kobayashi, Yayoi; Kayama, Fujio

2017-01-01

Lead (Pb) in petrol has been banned in developed countries. Despite the control of Pb in petrol since 2001, high levels were reported in the blood of pregnant women and children in Pakistan. However, the identification of sources of Pb has been elusive due to its pervasiveness. In this study, we assessed the lead intake of pregnant women and one- to three-year-old children from food, water, house dust, respirable dust, and soil. In addition, we completed the fingerprinting of the Pb isotopic ratios (LIR) of petrol and secondary sources (food, house-dust, respirable dust, soil, surma (eye cosmetics)) of exposure within the blood of pregnant women, newborns, and children. Eight families, with high (~50 μg/dL), medium (~20 μg/dL), and low blood levels (~10 μg/dL), were selected from 60 families. The main sources of exposure to lead for children were food and house-dust, and those for pregnant women were soil, respirable dust, and food. LIR was determined by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) with a two sigma uncertainty of ±0.03%. The LIR of mothers and newborns was similar. In contrast, surma, and to a larger extent petrol, exhibited a negligible contribution to both the child’s and mother’s blood Pb. Household wet-mopping could be effective in reducing Pb exposure. This intake assessment could be replicated for other developing countries to identify sources of lead and the burden of lead exposure in the population. PMID:28406467

Differential Immunotoxicity Induced by Two Different Windows of Developmental Trichloroethylene Exposure

PubMed Central

Gilbert, Kathleen M.; Woodruff, William; Blossom, Sarah J.

2014-01-01

Developmental exposure to environmental toxicants may induce immune system alterations that contribute to adult stage autoimmune disease. We have shown that continuous exposure of MRL+/+ mice to trichloroethylene (TCE) from gestational day (GD) 0 to postnatal day (PND) 49 alters several aspects of CD4+ T cell function. This window of exposure corresponds to conception-adolescence/young adulthood in humans. More narrowly defining the window of TCE developmental exposure causes immunotoxicity that would establish the stage at which avoidance and/or intervention would be most effective. The current study divided continuous TCE exposure into two separate windows, namely, gestation only (GD0 to birth (PND0)) and early-life only (PND0-PND49). The mice were examined for specific alterations in CD4+ T cell function at PND49. One potentially long-lasting effect of developmental exposure, alterations in retrotransposon expression indicative of epigenetic alterations, was found in peripheral CD4+ T cells from both sets of developmentally exposed mice. Interestingly, certain other effects, such as alterations in thymus cellularity, were only found in mice exposed to TCE during gestation. In contrast, expansion of memory/activation cell subset of peripheral CD4+ T cells were only found in mice exposed to TCE during early life. Different windows of developmental TCE exposure can have different functional consequences. PMID:24696780

Effects of Pb plus Cd mixtures on toxicity, and internal electrolyte and osmotic balance in the rainbow trout (Oncorhynchus mykiss).

PubMed

Clemow, Yvonne H; Wilkie, Michael P

2015-04-01

The physiological and toxicological effects of Cd and Pb have been thoroughly studied, but relatively little work has been done to determine how mixtures of these metals affect fishes in soft (<100 μmol L(-1)Ca(2+)) slightly acidic (pH ∼6) waters typical of many lakes in the Canadian Shield and other regions. Recently, it has been suggested that acute exposure to Cd plus Pb mixtures (3h) had greater than additive effects on both Ca(2+) and Na(+) influx, which could potentially exacerbate disturbances to ion balance and result in greater toxicity in rainbow trout (Oncorhynchus mykiss). The goal of the present study was to test this hypothesis by assessing the physiological and toxicological effects of Cd plus Pb mixtures over longer time periods (3-5 days), but at relatively low, more environmentally relevant concentrations of these metals. Accordingly, toxicity and measurements of blood acid-base regulation (PaO2, pHa), hematology (Ht, Hb, MCHC, and Protein), ionic composition (body ions and plasma Ca(2+), Na(+), Cl(-), osmolality), unidirectional Na(+) fluxes and branchial Na(+)/K(+)-ATPase activity were measured in rainbow trout exposed to Cd plus Pb mixtures. Experiments on rainbow trout, implanted with dorsal aortic catheters for repetitive blood sampling, demonstrated that exposure to Pb alone (26 nmol PbL(-1)) was less toxic than Cd alone (6 nmol CdL(-1)), which was much less toxic to the fish than a Cd plus Pb mixture (7 nmol CdL(-1) plus 45 nmol PbL(-1)), which led to greater than additive 80% mortality by 5d. Both Cd and Pb inhibited Na(+) influx over 3d exposure to the metals, which was partially offset by decreases in the diffusive efflux (outflux) of Na(+) across the gill. Despite an absence of detectable effects of Pb alone on plasma ion balance, Cd plus Pb mixtures exacerbated Cd-induced reductions in plasma Ca(2+) concentration, and resulted in pronounced reductions in plasma Na(+), Cl(-), and osmolality. No effects on Na(+)/K(+)-ATPase activity were noted following exposure to Cd, Pb or Pb plus Cd mixtures. We conclude that the greater than additive toxicity of Cd plus Pb mixtures observed in the present and previous studies is because these metals not only have common, but also independent binding sites and mechanisms of action, which could exacerbate the pathophysiological effects caused by each metal alone. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of combined exposure to pyridostigmine bromide and shaker stress on acoustic startle response, pre-pulse inhibition and open field behavior in mice.

PubMed

Dubovicky, M; Paton, S; Morris, M; Mach, M; Lucot, J B

2007-01-01

The present study investigated the effect of combined exposure of pyridostigmine bromide (PB) and chronic shaker stress on acoustic startle responses (ASR), pre-pulse inhibition (PPI) and open field behavior of adult C57BL/6J mice. PB (10 mg kg(-1) day(-1) for 7 days) or saline was administered subcutaneously using osmotic Alzet minipumps implanted under the skin on the back of the mice. At the same time, the mice were exposed to 7 days of intermittent shaker stress. They were tested for ASR (100 dB and 120 dB stimuli) and PPI (70 dB + 100 dB and 70 dB + 120 dB) in the acoustic startle monitor system. The mice were assessed during the shaker stress on days 2 and 7 and 7, 14, 21 and 28 days after discontinuation of treatment. Separate groups of mice were tested in the open field in 15 min sessions on days 1, 3 and 6 during shaker stress and PB treatment. Exposure of mice to PB resulted in an exaggerated ASR, reduced PPI and non-significant decrease in locomotor activity. These behavioral changes were apparent only during exposure to PB. Repeated shaker stress did not have any effect on sensorimotor functions or open field behavior of mice. There was no prolonged or delayed effect of PB and/or stress on individual behavioral variables. The study found C57BL/6J mice to be behaviorally sensitive to PB treatment. (c) 2007 John Wiley & Sons, Ltd.

Bioaccessibility and human health risk assessment of lead in soil from Daye City

NASA Astrophysics Data System (ADS)

Li, Q.; Li, F.; Xiao, M. S.; Cai, Y.; Xiong, L.; Huang, J. B.; Fu, J. T.

2018-01-01

Lead (Pb) in soil from 4 sampling sites of Daye City was studied. Bioaccessibilities of Pb in soil were determined by the method of simplified bioaccessible extraction test (SBET). Since traditional health risk assessment was built on the basis of metal total content, the risk may be overestimated. Modified human health risk assessment model considering bioaccessibility was built in this study. Health risk of adults and children exposure to Pb based on total contents and bioaccessible contents were evaluated. The results showed that bioaccessible content of Pb in soil was much lower than its total content, and the average bioaccessible factor (BF) was only 25.37%. The hazard indexes (HIs) for adults and children calculated by two methods were all lower than 1. It indicated that there were no no-carcinogenic risks of Pb for human in Daye. By comparing with the results, the average bioaccessible HIs for adults and children were lower than the total one, which was due to the lower hazard quotient (HQ). Proportions of non-carcinogenic risk exposure to Pb via different pathways have also changed. Particularly, the most main risk exposure pathway for adults turned from the oral ingestion to the inhalation.

Effects of lead nitrate (PbNO3) on the glucose and cortisol hormone levels in common carp, Cyprinus carpio.

PubMed

Zare, S; Afaghi, A; Heidari, R; Asadpoor, Y; Shiri, S

2007-08-01

The objective of this study was to evaluate the possible effects of PbNO3 exposure on variations of glucose and cortisol levels in Cyprinus carpio. Fish were subjected to two sub-lethal concentrations of PbNO3 for 14 days. Blood samples were isolated from the fish following the exposure, to measure the levels of cortisol and glucose compared to the control group. We found significant increases (p<0.05) in the levels of blood cortisol in two groups of fish after 14 days of exposure to two concentrations of PbNO3 (1.3 and 2.6 mg L (-1)) The results showed significant increases in the glucose levels of both fish groups exposed for 14 days In the later treatment, the rate of increase in group II (exposed to 2.6 mg L(-1) PbNO3) was higher than that of group I (exposed to 1.3 mg L(-1) PbNO3) (P = 0 compare to P = 0.007). Present findings attest that exposing to waterborne lead would affect the levels of both glucose and cortisol in Cyprinus carpio.

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.

Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house

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

Beauchemin, Suzanne; MacLean, Lachlan C.W.; Rasmussen, Pat E.

Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pbmore » species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 {micro}m house dust samples. In the dust fraction <36 {micro}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.« less

Lead Speciation in Indoor Dust: A Case Study to Assess Old Paint Contribution in a Canadian Urban House

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

S Beauchemin; L MacLean; P Rasmussen

Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pbmore » species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 m house dust samples. In the dust fraction <36 {mu}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.« less

Insect transferrin functions as an antioxidant protein in a beetle larva.

PubMed

Kim, Bo Yeon; Lee, Kwang Sik; Choo, Young Moo; Kim, Iksoo; Je, Yeon Ho; Woo, Soo Dong; Lee, Sang Mong; Park, Hyun Cheol; Sohn, Hung Dae; Jin, Byung Rae

2008-06-01

In insects transferrin is known as an iron transporter, an antibiotic agent, a vitellogenin, and a juvenile hormone regulated protein. Here, a novel functional role for insect transferrin as an antioxidant protein is demonstrated. Stressors, such as heat shock, fungal challenge, and H(2)O(2) exposure, cause upregulation of the white-spotted flower chafer Protaetia brevitarsis (Coleoptera: Scarabaeidae) transferrin (PbTf) mRNA in the fat body and increases PbTf protein levels in the hemolymph. RNA interference (RNAi) treated PbTf reduction causes increased iron and H(2)O(2) levels in the hemolymph and results in induction of apoptotic cell death in the fat body during exposure to stress. The observed effects of PbTf RNAi suggest that PbTf inhibits stress-induced apoptosis by diminishing the Fenton reaction via the binding of iron, thus supporting an antioxidant role for PbTf in stress responses.

Lead exposure in young children over a 5-year period from urban environments using alternative exposure measures with the US EPA IEUBK model - A trial.

PubMed

Gulson, Brian; Taylor, Alan; Stifelman, Marc

2018-02-01

The US Environmental Protection Agency (EPA) Integrated Exposure Uptake Biokinetic (IEUBK) model has been widely used to predict blood lead (PbB) levels in children especially around industrial sites. Exposure variables have strongly focussed on the major contribution of lead (Pb) in soil and interior dust to total intake and, in many studies, site-specific data for air, water, diet and measured PbB were not available. We have applied the IEUBK model to a comprehensive data set, including measured PbB, for 108 children monitored over a 5-year period in Sydney, New South Wales, Australia. To use this data set, we have substituted available data (with or without modification) for standard inputs as needed. For example, as an alternative measure for soil Pb concentration (μg/g), we have substituted exterior dust sweepings Pb concentration (μg/g). As alternative measures for interior dust Pb concentration (μg/g) we have used 1) 30-day cumulative petri dish deposition data (PDD) (as µg Pb/m 2 /30days), or 2) hand wipe data (as μg Pb/hand). For comparison, simulations were also undertaken with estimates of dust Pb concentration derived from a prior regression of dust Pb concentration (μg/g) on dust Pb loading (μg/ft 2 ) as concentration is the unit specified for the Model. Simulations for each subject using observed data aggregated over the 5-year interval of the study, the most usual application of the IEUBK model, showed using Wilcoxon tests that there was a significant difference between the observed values and the values predicted by the Model containing soil with hand wipes (p < 0.001), and soil and PDD (p = 0.026) but not those for the other two sets of predictors, based on sweepings and PDD or sweepings and wipes. Overall, simulations of the Model using alternative exposure measures of petri dish dust (and possibly hand wipes) instead of vacuum cleaner dust and dust sweepings instead of soil provide predicted PbB which are generally consistent with each other and observed values. The predicted geometric mean PbBs were 2.17 ( ± 1.24) μg/dL for soil with PDD, 1.95 ( ± 1.17) μg/dL for soil with hand wipes, 2.36 ( ± 1.75) μg/dL for sweepings with PDD, and 2.15 ( ± 1.69) for sweepings with hand wipes. These results are in good agreement with the observed geometric mean PbB of 2.46 ( ± 0.99) μg/dL. In contrast to all other IEUBK model studies to our knowledge, we have stratified the data over the age ranges from 1 to 5 years. The median of the predicted values was lower than that for the observed values for every combination of age and set of measures; in some cases, the difference was statistically significant. The differences between observed and predicted PbB tended to be greatest for the soil plus wipes measure and for the oldest age group. Use of 'default dust' values calculated from the site-specific soil values, a common application of the IEUBK model, results in predicted PbB about 22% (range 0 to 52%) higher than those from soil with PDD data sets. Geometric mean contributions estimated from the Model to total Pb intake for a child aged 1-2 years was 0.09% for air, 42% for diet, 5.3% for water and 42% for soil and dust. Our results indicate that it is feasible to use alternative measures of soil and dust exposure to provide reliable predictions of PbB in urban environments. Copyright © 2017 Elsevier Inc. All rights reserved.

Exogenous Nitric Oxide (NO) Interferes with Lead (Pb)-Induced Toxicity by Detoxifying Reactive Oxygen Species in Hydroponically Grown Wheat (Triticum aestivum) Roots

PubMed Central

Kaur, Gurpreet; Singh, Harminder Pal; Batish, Daizy R.; Mahajan, Priyanka; Kohli, Ravinder Kumar; Rishi, Valbha

2015-01-01

Nitric Oxide (NO) is a bioactive signaling molecule that mediates a variety of biotic and abiotic stresses. The present study investigated the role of NO (as SNP [sodium nitroprusside]) in ameliorating lead (Pb)-toxicity in Triticum aestivum (wheat) roots. Pb (50 and 250 μM) alone and in combination with SNP (100 μM) was given to hydroponically grown wheat roots for a period of 0–8 h. NO supplementation reduced the accumulation of oxidative stress markers (malondialdehyde, conjugated dienes, hydroxyl ions and superoxide anion) and decreased the antioxidant enzyme activity in wheat roots particularly up to 6 h, thereby suggesting its role as an antioxidant. NO ameliorated Pb-induced membrane damage in wheat roots as evidenced by decreased ion-leakage and in situ histochemical localization. Pb-exposure significantly decreased in vivo NO level. The study concludes that exogenous NO partially ameliorates Pb-toxicity, but could not restore the plant growth on prolonged Pb-exposure. PMID:26402793

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

Korean research project on the integrated exposure assessment of hazardous substances for food safety

PubMed Central

Lim, Ji-Ae; Kwon, Ho-Jang; Ha, Mina; Kim, Ho; Oh, Se Young; Kim, Jeong Seon; Lee, Sang-Ah; Park, Jung-Duck; Hong, Young-Seoub; Sohn, Seok-Joon; Pyo, Heesoo; Park, Kyung Su; Lee, Kwang-Geun; Kim, Yong Dae; Jun, Sangil; Hwang, Myung Sil

2015-01-01

Objectives: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). Methods: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. Results: Pb and Cd were the highest (median value) in the seaweed (94.2 μg/kg for Pb; 594 μg/kg for Cd), and Hg was the highest in the fish (46.4 μg/kg). The dietary exposure level (median value) of Pb was 0.14 μg/kg body weight (bw)/d, 0.18 μg/kg bw/d for Cd, and 0.07 μg/kg bw/d for Hg. Those with a blood Pb level of less than 5.00 μg/dL (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than 0.30 μg/L (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than 5.00 μg/L (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. Conclusions: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union. PMID:26184046

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...

The effect of EDDS and citrate on the uptake of lead in hydroponically grown Matthiola flavida.

PubMed

Mohtadi, Ahmad; Ghaderian, Seyed Majid; Schat, Henk

2013-10-01

Root and shoot lead concentrations and the impact of chelating agents on these were investigated in two populations of the novel metallophyte Matthiola flavida. Plants were exposed in hydroponics to Pb(NO3)2, supplied alone, or in combination with citric acid, or EDDS. When supplied at concentrations expected to bind about 95% of the Pb in a solution containing 1-μM Pb (1000 μM citrate or 3.1 μM EDDS, respectively), the root and shoot Pb concentrations were dramatically lowered, in comparison with a 1-μM free ionic Pb control exposure. A 1-mM EDDS+1-μM Pb treatment decreased the plants' Pb concentrations further, even to undetectable levels in one population. At 100 μM Pb in a 1-mM EDDS-amended solution the Pb concentration increased strongly in shoots, but barely in roots, in comparison with the 1-μM Pb+1-mM EDDS treatment, without causing toxicity symptoms. Further increments of the Pb concentration in the 1-mM EDDS-amended solution, i.e. to 800 and 990 μM, caused Pb hyperaccumulation, both in roots and in shoots, associated with a complete arrest of root growth and foliar necrosis. M. flavida seemed to be devoid of constitutive mechanisms for uptake of Pb-citrate or Pb-EDDS complexes. Hyperaccumulation of Pb-EDDS occurred only at high exposure levels. Pb-EDDS was toxic, but is much less so than free Pb. Free EDDS did not seem to be toxic at the concentrations tested. Copyright © 2013 Elsevier Ltd. All rights reserved.

Developmental Ethanol Exposure Leads to Dysregulation of Lipid Metabolism and Oxidative Stress in Drosophila

PubMed Central

Logan-Garbisch, Theresa; Bortolazzo, Anthony; Luu, Peter; Ford, Audrey; Do, David; Khodabakhshi, Payam; French, Rachael L.

2014-01-01

Ethanol exposure during development causes an array of developmental abnormalities, both physiological and behavioral. In mammals, these abnormalities are collectively known as fetal alcohol effects (FAE) or fetal alcohol spectrum disorder (FASD). We have established a Drosophila melanogaster model of FASD and have previously shown that developmental ethanol exposure in flies leads to reduced expression of insulin-like peptides (dILPs) and their receptor. In this work, we link that observation to dysregulation of fatty acid metabolism and lipid accumulation. Further, we show that developmental ethanol exposure in Drosophila causes oxidative stress, that this stress is a primary cause of the developmental lethality and delay associated with ethanol exposure, and, finally, that one of the mechanisms by which ethanol increases oxidative stress is through abnormal fatty acid metabolism. These data suggest a previously uncharacterized mechanism by which ethanol causes the symptoms associated with FASD. PMID:25387828

Residents health risk of Pb, Cd and Cu exposure to street dust based on different particle sizes around zinc smelting plant, Northeast of China.

PubMed

Zhou, Qiuhong; Zheng, Na; Liu, Jingshuang; Wang, Yang; Sun, Chongyu; Liu, Qiang; Wang, Heng; Zhang, Jingjing

2015-04-01

The residents health risk of Pb, Cd and Cu exposure to street dust with different particle sizes (<100 and <63 μm) near Huludao Zinc Plant (HZP) was investigated in this study. The average concentrations of Pb, Cd and Cu in the <100-μm and <63-μm dust were 1,559, 178.5, 917.9 and 2,099, 198.4, 1,038 mg kg(-1), respectively. It showed that smaller particles tended to contain higher element concentrations. Metals in dust around HZP decreased gradually from the zinc smelter to west and east directions. There was significantly positive correlation among Pb, Cd and Cu in street dust with different particle sizes. The contents of Pb, Cd and Cu in dust increased with decreasing pH or increasing organic matter. Non-carcinogenic health risk assessment showed that the health index (HI) for children and adult exposed to <63-μm particles were higher than exposed to <100-μm particles, which indicated that smaller particles tend to have higher non-carcinogenic health risk. Non-carcinogenic risk of Pb was the highest in both particle sizes, followed by Cd and Cu. HI for Pb and Cd in both particle sizes for children had exceeded the acceptable value, indicated that children living around HZP were experiencing the non-carcinogenic health risk from Pb and Cd exposure to street dust.

Environmental Lead (Pb) Exposure Versus Fatty Acid Content in Blood and Milk of the Mother and in the Blood of Newborn Children.

PubMed

Baranowska-Bosiacka, Irena; Kosińska, Ida; Jamioł, Dominika; Gutowska, Izabela; Prokopowicz, Adam; Rębacz-Maron, Ewa; Goschorska, Marta; Olszowski, Tomasz; Chlubek, Dariusz

2016-04-01

Significant progress in understanding the effects of the neurotoxic action of lead (Pb) in young organisms had led to reduction of "safe" level in the blood (Pb-B) to 5 μg/dL in children and pregnant women. Prolonged exposure to relatively low levels of Pb, generally asymptomatic and subclinical (i.e., microintoxication), is currently the dominant form of environmental poisoning, and its negative effects on health may appear after many years, e.g., secondary contamination from Pb bone deposits released in pregnancy. Therefore, the aim of this study was to investigate the effect of environmental exposure (urban areas) of mothers to Pb, on its levels in their milk and blood and in the blood of newborns. Moreover, the aim was to determine the fatty acid profile in the mothers' blood and milk and in the blood of newborns. We also wanted to find if infant birth weight depends on Pb blood levels, as well as on Pb and fatty acid levels in the blood and milk of the mothers. Finally, we examined if the mothers' weight and body mass index (BMI) before pregnancy influenced the concentration of Pb and fatty acid profile in the blood and milk of mothers and in the blood of their children. Analysis of fatty acids elaidic (C18:1, 9t), oleic (C18:1, 9c), vaccenic (C18:1, 11t), cis-vaccenic (C18:1, 11c), linoleic (C18:2, cis), γ-linolenic (C18:3, n-6), α-linolenic (C18:3, n-3), arachidonic (C20:4, n-6), eicosapentaenoic (C20:5, n-3), and docosahexaenoic (C22:6, n-3) was conducted by gas chromatography. The concentration of Pb in the whole blood and milk were determined by atomic absorption spectrometry with graphite furnace atomization and Zeeman correction. Our study established a significant and strong correlation between the content of Pb in the blood of the mother and the child. This supports the assumption that the transport of Pb through the placenta is neither regulated nor selective. Environmental maternal exposure to lead resulting in Pb-B levels considered safe for pregnant women had no effect on infant birth weight, the concentration of fatty acids in the blood and milk of mothers, or in the blood of newborns. Mothers' weight and BMI before pregnancy had no effect on the concentration of Pb and studied fatty acid profile.

Neurobehavioral Impairments Caused by Developmental Imidacloprid Exposure in Zebrafish

PubMed Central

Crosby, Emily B.; Bailey, Jordan M.; Oliveri, Anthony N.; Levin, Edward D.

2015-01-01

BACKGROUND Neonicotinoid insecticides are becoming more widely applied as organophosphate (OP) insecticides are decreasing in use. Because of their relative specificity to insect nicotinic receptors, they are thought to have reduced risk of neurotoxicity in vertebrates. However, there is scant published literature concerning the neurobehavioral effects of developmental exposure of vertebrates to neonicotinoids. METHODS Using zebrafish, we investigated the neurobehavioral effects of developmental exposure to imidacloprid, a prototypic neonicotinoid pesticide. Nicotine was also administered for comparison. Zebrafish were exposed via immersion in aqueous solutions containing 45 μM or 60 μM of imidacloprid or nicotine (or vehicle control) from 4 h to 5 d post fertilization. The functional effects of developmental exposure to both imidacloprid and nicotine were assessed in larvae using an activity assay and during adolescence and adulthood using a battery of neurobehavioral assays, including assessment of sensorimotor response and habituation in a tactile startle test, novel tank swimming, and shoaling behavior. RESULTS In larvae, developmental imidacloprid exposure at both doses significantly decreased swimming activity. The 5D strain of zebrafish were more sensitive to both nicotine and imidacloprid than the AB* strain. In adolescent and adult fish, developmental exposure to imidacloprid significantly decreased novel tank exploration and increased sensorimotor response to startle stimuli. While nicotine did not affect novel tank swimming, it increased sensorimotor response to startle stimuli at the low dose. No effects of either compound were found on shoaling behavior or habituation to a startling stimulus. DISCUSSION Early developmental exposure to imidacloprid has both early-life and persisting effects on neurobehavioral function in zebrafish. Its developmental neurotoxicity should be further investigated. PMID:25944383

Co-exposure to pyridostigmine bromide, DEET, and/or permethrin causes sensorimotor deficit and alterations in brain acetylcholinesterase activity.

PubMed

Abou-Donia, Mohamed B; Dechkovskaia, Anjelika M; Goldstein, Larry B; Abdel-Rahman, Ali; Bullman, Sarah L; Khan, Wasiuddin A

2004-02-01

Military personnel deployed in the Persian Gulf War (PGW) were exposed to a combination of chemicals, including pyridostigmine bromide (PB), DEET, and permethrin. We investigated the dose-response effects of these chemicals, alone or in combination, on the sensorimotor performance and cholinergic system of male Sprague-Dawley rats. Animals were treated with a daily dermal dose of DEET and/or permethrin for 60 days and/or PB (gavage) during the last 15 days. Neurobehavioral performance was assessed on day 60 following the beginning of the treatment with DEET and permethrin. The rats were sacrificed 24 h after the last treatment for biochemical evaluations. PB alone, or in combination with DEET, or DEET and permethrin resulted in deficits in beam-walk score and longer beam-walk times compared to controls. PB alone, or in combination with DEET, permethrin, or DEET and permethrin caused impairment in incline plane performance and forepaw grip strength. PB alone at all doses slightly inhibited plasma butyrylcholinesterase activity, whereas combination of PB with DEET or permethrin increased its activity. Brainstem acetylcholinesterase (AChE) activity significantly increased following treatment with combinations of either DEET or permethrin at all doses, whereas the cerebellum showed a significant increase in AChE activity following treatment with a combination of PB/DEET/permethrin. Co-exposure to PB, DEET, and permethrin resulted in significant inhibition in AChE in midbrain. PB alone or in combination with DEET and permethrin at all doses increased ligand binding for m2 muscarinic acetylcholine receptor in the cortex. In addition, PB and DEET together or a combination of PB, DEET, and permethrin significantly increased ligand binding for nicotinic acetylcholine receptor. These results suggest that exposure to various doses of PB, alone and in combination with DEET and permethrin, leads to sensorimotor deficits and differential alterations of the cholinergic system in the CNS.

Potential Of Microalgae Chlorella vulgaris As Bioremediation Agents of Heavy Metal Pb (Lead) On Culture Media

NASA Astrophysics Data System (ADS)

Dewi, Endah Rita Sulistya; Nuravivah, Riza

2018-02-01

The purpose of this study to determine the ability of Chlorella vulgaris in absorbing Pb (lead) and the effect of the variation of Pb metal concentration on the growth of Chlorella vulgaris.This study using an experimental study with complete random design with 4 treatments, namely control (without the addition of metal), Pb1 (addition of metal 1 mg / l), Pb3 (3 mg / l) and Pb5 (5 mg / l), respectively 3 replications. Exposure Pb ion in Chlorella vulgaris for 7 days. Analysis of the metal content of Pb concentration performed on culture media after exposure it at 3 hours after dispersion Chlorella vulgaris and on day 7 of culture using the AAS method. Do also counting the growth of cells each day. The results of the analysis of the average metal content of Pb in the culture medium at the end of the study was the control (0.1980), Pb1 (0.1453), Pb3 (0.4144) and Pb5 (0.5305). While the average growth of Chlorella vulgaris at the end of the study were control (630.1116 x 104), Pb1 (829.0012 x 104), Pb3 (1069.9446 x 104) and Pb 5 (808.94450 x 104). The results of the analysis of the content of Pb in the F test shown that the difference in concentration of water Pb given real influence on the ability of Chlorella vulgaris in absorbing Pb and growth. The conclusion of this study was Chlorella vulgaris has the ability to absorb metals in the waters, and the provision of various concentrations of Pb can affect the growth of Chlorella vulgaris.

Effect of vitamin E on lead exposure-induced learning and memory impairment in rats.

PubMed

Khodamoradi, Nasrin; Komaki, Alireza; Salehi, Iraj; Shahidi, Siamak; Sarihi, Abdolrahman

2015-05-15

Chronic lead (Pb(2+)) exposure has been associated with learning and memory impairments, whereas vitamin E improves cognitive deficits. In this study, using a passive avoidance learning model in rats, we investigated the effects of vitamin E on Pb(2+) exposure-induced learning and memory impairments in rats. In the present study, 56 Wistar male rats (weighting 230-250g) were divided into eight groups (n=7). The Pb(2+) exposure involved gavages of lead acetate solution using three different doses (0.05%, 0.1%, and 0.2%) and the vitamin E consisted of three different doses (10, 25, 50μg/rat) for 30days. After the 30-day period, the rats were tested using a passive avoidance task (acquisition test). In a retrieval test conducted 48h after the training, step through latency (STL) and time in the dark compartment (TDC) were recorded. The statistical analysis of data was performed using ANOVA followed by Tukey's post hoc analysis. In all cases, differences were considered significant if p<0.05. The results of the present study showed that chronic exposure to high doses of Pb(2+) significantly increased both the number of trails required for learning and the TDC, whereas it decreased the STL in the passive avoidance test. Administration of vitamin E ameliorated the effects of Pb(2+) on animal behavior in the passive avoidance learning and memory task. Our results indicate that impairments of learning and memory in Pb(2+)-exposed rats are dose dependent and can be inhibited by antioxidants such as vitamin E. Copyright © 2015 Elsevier Inc. All rights reserved.

Case-only gene-environment interaction between ALAD tagSNPs and occupational lead exposure in prostate cancer.

PubMed

Neslund-Dudas, Christine; Levin, Albert M; Rundle, Andrew; Beebe-Dimmer, Jennifer; Bock, Cathryn H; Nock, Nora L; Jankowski, Michelle; Datta, Indrani; Krajenta, Richard; Dou, Q Ping; Mitra, Bharati; Tang, Deliang; Rybicki, Benjamin A

2014-05-01

Black men have historically had higher blood lead levels than white men in the U.S. and have the highest incidence of prostate cancer in the world. Inorganic lead has been classified as a probable human carcinogen. Lead (Pb) inhibits delta-aminolevulinic acid dehydratase (ALAD), a gene recently implicated in other genitourinary cancers. The ALAD enzyme is involved in the second step of heme biosynthesis and is an endogenous inhibitor of the 26S proteasome, a master system for protein degradation and a current target of cancer therapy. Using a case-only study design, we assessed potential gene-environment (G × E) interactions between lifetime occupational Pb exposure and 11 tagSNPs within ALAD in black (N = 260) and white (N = 343) prostate cancer cases. Two ALAD tagSNPs in high linkage disequilibrium showed significant interaction with high Pb exposure among black cases (rs818684 interaction odds ratio or IOR = 2.73, 95% CI 1.43-5.22, P = 0.002; rs818689 IOR = 2.20, 95% CI 1.15-4.21, P = 0.017) and an additional tagSNP, rs2761016, showed G × E interaction with low Pb exposure (IOR = 2.08, 95% CI 1.13-3.84, P = 0.019). Further, the variant allele of rs818684 was associated with a higher Gleason grade in those with high Pb exposure among both blacks (OR 3.96, 95% CI 1.01-15.46, P = 0.048) and whites (OR 2.95, 95% CI 1.18-7.39, P = 0.020). Genetic variation in ALAD may modify associations between Pb and prostate cancer. Additional studies of ALAD, Pb, and prostate cancer are warranted and should include black men. Prostate 74:637-646, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

The role of marine biotoxins on the trophic transfer of Mn and Zn in fish.

PubMed

Pouil, Simon; Clausing, Rachel J; Metian, Marc; Bustamante, Paco; Dechraoui Bottein, Marie-Yasmine

2018-05-01

Essential nutrients are critical for physiological processes of organisms. In fish, they are obtained primarily from the diet, and their transfer and accumulation are known to be impacted by environmental variables such as water temperature, pH and salinity, as well as by diet composition and matrices. Yet, prey items consumed by fish may also contain toxic compounds such as marine toxins associated with harmful algae. These biotoxins have the potential to affect essential trace element assimilation in fish through chemical interactions such as the formation of trace element-toxin complexes or by affecting general fish physiology as in the modification of ion-specific transport pathways. We assessed the influence of dietary exposure to brevetoxins (PbTxs), ichthyotoxic neurotoxins produced by the dinoflagellate Karenia brevis, on trophic transfer of two essential trace elements, Mn and Zn, in a fish model. Using ecologically relevant concentrations of PbTxs and trace elements in controlled laboratory conditions, juvenile turbots Scophthalmus maximus were given food containing PbTxs before or at the same time as a feeding with radiotracers of the chosen essential elements ( 54 Mn and 65 Zn). Treatments included simultaneous exposure (PbTxs +  54 Mn +  65 Zn) in a single-feeding, 3-week daily pre-exposure to dietary PbTx followed by a single feeding with 54 Mn and 65 Zn, and a control ( 54 Mn and 65 Zn only). After a 21-day depuration period, turbot tissue brevetoxin levels were quantified and assimilation efficiencies of 54 Mn and 65 Zn were assessed. PbTxs were found in turbot tissues in each exposure treatment, demonstrating dietary trophic transfer of these toxins; yet, no differences in assimilation efficiencies of Mn or Zn were found between treatments or the control (p > 0.05). These results indicate that, in our experimental conditions, PbTx exposure does not significantly affect the trophic transfer of Mn and Zn in fish. Copyright © 2018 Elsevier B.V. All rights reserved.

Increased memory T cell populations in Pb-exposed children from an e-waste-recycling area.

PubMed

Cao, Junjun; Xu, Xijin; Zhang, Yu; Zeng, Zhijun; Hylkema, Machteld N; Huo, Xia

2018-03-01

Chronic exposure to heavy metals could affect cell-mediated immunity. The aim of this study was to explore the status of memory T cell development in preschool children from an e-waste recycling area. Blood lead (Pb) levels, peripheral T cell subpopulations, and serum levels of cytokines (IL-2/IL-7/IL-15), relevant to generation and homeostasis of memory T cells were evaluated in preschool children from Guiyu (e-waste-exposed group) and Haojiang (reference group). The correlations between blood Pb levels and percentages of memory T cell subpopulations were also evaluated. Guiyu children had higher blood Pb levels and increased percentages of CD4 + central memory T cells and CD8 + central memory T cells than in the Haojiang group. Moreover, blood Pb levels were positively associated with the percentages of CD4 + central memory T cells. In contrast, Pb exposure contributed marginally in the change of percentages of CD8 + central memory T cells in children. There was no significant difference in the serum cytokine levels between the e-waste-exposed and reference children. Taken together, preschool children from an e-waste recycling area suffer from relatively higher levels of Pb exposure, which might facilitate the development of CD4 + central memory T cells in these children. Copyright © 2017. Published by Elsevier B.V.

Lead and cadmium in the blood of nine species of seabirds, Marion Island, South Africa.

PubMed

Summers, Carly F; Bowerman, William W; Parsons, Nola; Chao, Wayne Y; Bridges, William C

2014-10-01

Levels of lead (Pb) and cadmium (Cd) were investigated as potential stressors in nine species of breeding seabirds on Marion Island, South Africa. The majority of blood Pb levels (95 %) were below background exposure levels. Species was a significant factor in ranked means analysis for mean blood Pb levels. Fewer individual blood Cd levels (<60 %) were within background exposure levels and species was not significant. Elevated levels of Cd have been documented in other seabird species without apparent outward effects, which suggests that seabirds may be adapted to high cadmium environments, particularly from their diets. Overall, the results suggest Pb and Cd are not primary causes for concern in these seabirds.

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

Nelson, Y.M.; DiSante, C.J.; Lion, L.W.

Toxic trace metals have been implicated as a potential cause of recent flamingo kills at Lake Nakuru, Kenya. Chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) have accumulated in the lake sediments as a result of unregulated discharges and because this alkaline lake has no natural outlet. Lesser flamingos (Phoeniconaias minor) at Lake Nakuru feed predominantly on the cyanobacterium Spirulina platensis, and because of their filter-feeding mechanism, they are susceptible to exposure to particle-bound metals. Trace metal adsorption isotherms to lake sediments and S. platensis were obtained under simulated lake conditions, and a mathematical model was developed to predictmore » metal exposure via filter feeding based on predicted trace metal phase distribution. Metal adsorption to suspended solids followed the trend Pb {much_gt} Zn > Cr > Cu, and isotherms were linear up to 60 {micro}g/L. Adsorption to S. platensis cells followed the trend Pb {much_gt} Zn > Cu > Cr and fit Langmuir isotherms for Cr, Cu and Zn and a linear isotherm for Pb. Predicted phase distributions indicated that Cr and Pb in Lake Nakuru are predominantly associated with suspended solids, whereas Cu and Zn are distributed more evenly between the dissolved phase and particulate phases of both S. platensis and suspended solids. Based on established flamingo feeding rates and particle size selection, predicted Cr and Pb exposure occurs predominantly through ingestion of suspended solids, whereas Cu and Zn exposure occurs through ingestion of both suspended solids and S. platensis. For the lake conditions at the time of sampling, predicted ingestion rates based on measured metal concentrations in lake suspended solids were 0.71, 6.2, 0.81, and 13 mg/kg-d for Cr, Cu, Pb, and Zn, respectively.« less

Effects of lead exposure on hippocampal metabotropic glutamate receptor subtype 3 and 7 in developmental rats.

PubMed

Xu, Jian; Yan, Huai C; Yang, Bo; Tong, Lu S; Zou, Yu X; Tian, Ying

2009-04-20

A complete explanation of the mechanisms by which Pb2+ exerts toxic effects on developmental central nervous system remains unknown. Glutamate is critical to the developing brain through various subtypes of ionotropic or metabotropic glutamate receptors (mGluRs). Ionotropic N-methyl-D-aspartate receptors have been considered as a principal target in lead-induced neurotoxicity. The relationship between mGluR3/mGluR7 and synaptic plasticity had been verified by many recent studies. The present study aimed to examine the role of mGluR3/mGluR7 in lead-induced neurotoxicity. Twenty-four adult and female rats were randomly selected and placed on control or 0.2% lead acetate during gestation and lactation. Blood lead and hippocampal lead levels of pups were analyzed at weaning to evaluate the actual lead content at the end of the exposure. Impairments of short -term memory and long-term memory of pups were assessed by tests using Morris water maze and by detection of hippocampal ultrastructural alterations on electron microscopy. The impact of lead exposure on mGluR3 and mGluR7 mRNA expression in hippocampal tissue of pups were investigated by quantitative real-time polymerase chain reaction and its potential role in lead neurotoxicity were discussed. Lead levels of blood and hippocampi in the lead-exposed rats were significantly higher than those in the controls (P < 0.001). In tests using Morris Water Maze, the overall decrease in goal latency and swimming distance was taken to indicate that controls had shorter latencies and distance than lead-exposed rats (P = 0.001 and P < 0.001 by repeated-measures analysis of variance). On transmission electron microscopy neuronal ultrastructural alterations were observed and the results of real-time polymerase chain reaction showed that exposure to 0.2% lead acetate did not substantially change gene expression of mGluR3 and mGluR7 mRNA compared with controls. Exposure to lead before and after birth can damage short-term and long-term memory ability of young rats and hippocampal ultrastructure. However, the current study does not provide evidence that the expression of rat hippocampal mGluR3 and mGluR7 can be altered by systemic administration of lead during gestation and lactation, which are informative for the field of lead-induced developmental neurotoxicity noting that it seems not to be worthwhile to include mGluR3 and mGluR7 in future studies.

X-ray fluorescence for quantification of lead and strontium in vivo

NASA Astrophysics Data System (ADS)

Specht, Aaron James

Lead (Pb) is a toxicant well known for its effects on almost every organ system in the body. Pb use in industry has declined since removal of Pb from gasoline, but many developing countries still have significant use of Pb. Exposure to Pb has been linked with diseases causing neurodegeneration and thus have lasting effects long after the initial exposure. Another metal, strontium (Sr), has been linked with bone disease in particular situations and shown to have uses in treating osteoporosis as a supplement. However, there are no studies of the effects of Sr using a meaningful biomarker. The most commonly used biomarkers for Pb and Sr exposures are blood Pb and Sr; however, blood tests are unable to identify long-term exposure levels due to the short half-life of these metals in blood. Bone stores of Pb and Sr have a half-life of years to decades and serve as a biomarker of long-term exposure. X-ray fluorescence has been used to measure bone Pb and Sr. However, current systems have limitations with radioisotope sources, bulky equipment, and long measurement times. A portable XRF device capable of measurement of bone Pb and Sr, overcomes the limitation of the current systems and has been developed in this work. The detection limit of the portable XRF for bone Pb and Sr was found to be 11 ppm and 5 ppm respectively at 5 mm of skin thickness. The portable XRF will have limitations of measurement based on an individual's skin thickness. The device was calibrated using standard phantoms and validated with in-lab samples, which demonstrated good agreement between KXRF and portable XRF measurements with strong correlations between goat bone, cadaver bone, and phantom measurements. In a population study of Pb poisoned children the portable XRF was further validated and a significant correlation between KXRF measured bone Pb and portable XRF measured bone Pb was identified; however, the device had limitations based on anatomical differences unaccounted for in children from our calibration. Adaptations of our calibration to account for the differences in children's bone can be used to further improve on the results we obtained. Pb biokinetics was studied in these children, and the blood Pb half-life in the children was calculated to be about 10 days, which is much short than the 30 day half-life identified for adults. Bone Sr was measured in these children and a significant correlation with age was identified, indicating the Sr accumulates in bone. A novel high-energy x-ray tube based KXRF measurement system was tested for its feasibility of in vivo measurement of metals in bone using Monte Carlo (MC) simulation. The novel system shows a combination of the advantages of the portable XRF with a smaller scale device, x-ray tube source, and room temperature detector, as well as the advantages of the KXRF of minimal soft tissue signal degradation with more applicability to a wider range of populations. This device, with an optimized x-ray tube and uranium target of 0.056 mm, was found to have a detection limit for bone Pb measurement of about 3.6 ppm and could be adapted for measurements of multiple metals.

Ecotoxicology: Lead

USGS Publications Warehouse

Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

2008-01-01

Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

Dietary zinc promotes immuno-biochemical plasticity and protects fish against multiple stresses.

PubMed

Kumar, Neeraj; Krishnani, K K; Kumar, Paritosh; Jha, Ashish Kumar; Gupta, Sanjay Kumar; Singh, N P

2017-03-01

The abiotic and biotic stress is an episode that effect on regulatory, neuro-endocrine and immune systems of animals including fish. The stress creates stimulatory and suppressive of immune system resulting in increases the incidence of infection. In view of these points, we have conducted an experiment to mitigate the stress through a nutritional approach through Zinc (Zn) supplementation in Pangasius hypophthalmus (initial weight-3.65 ± 0.75 g). Three isocaloric and isonitrogenous diets with graded levels of zinc 0, 10 and 20 mg/kg were prepared and fed to seven different groups with each in triplicate. The experimental group as follows as normal water with control diet (Ctr/Ctr), lead (Pb) exposed and fed with control diet (Ctr/Pb), control diet and exposed to Pb and temperature (Ctr/Pb-T), Zn 10 mg/kg fed without stressors (Zn- 10 mg/kg), Zn 20 mg/kg fed without stressors (Zn-20 mg/kg), Zn 10 mg/kg fed and Pb and temperature exposed (Pb-T/Zn 10 mg/kg) and Zn 20 mg/kg fed and exposed to Pb and temperature (Pb-T/Zn 20 mg/kg). The Pb in treated water was maintained at the level of 1/20th of LC 50 (4 ppm) and temperature at 34  ° C in exposure groups. The neutraceuticals role of dietary Zn was studied in terms of antioxidative enzymes (catalase, superoxide dismutase, glutathione-S-transferase), stress markers (Heat shock protein 70, cortisol, acetylcholine esterase, blood glucose, Vitamin C), immunological parameters (Total protein, albumin, globulin, A/G ratio and NBT) and subsequent challenge with Aeromonas veronii biovar sobria. The antioxidative enzymes, stress markers, albumin were significantly (p < 0.01) elevated, brain AChE and immuno-hematological parameters were significantly (p < 0.01) decreased due to lead (Pb) and temperature exposure. The relative survival (%) was reduced due to the concurrent effect of Pb, high temperature stress and bacterial challenge. Zinc at the rate of 10 and 20 mg/kg was found to be restore the biochemical and immunological parameters against concurrent exposure to lead (Pb), temperature and pathogenic infection. Results obtained in the present study indicate that supplementation of 10 and 20 mg/kg of Zn in the diet has a definitive role in the mitigation of lead (Pb) and temperature exposure along with pathogenic infection in P. hypophthalmus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microglial disruption in young mice with early chronic lead exposure☆

PubMed Central

Sobin, Christina; Montoya, Mayra Gisel Flores; Parisi, Natali; Schaub, Tanner; Cervantes, Miguel; Armijos, Rodrigo X.

2013-01-01

The mechanisms by which early chronic lead (Pb) exposure alter brain development have not been identified. We examined neuroimmune system effects in C57BL/6J mice with Pb exposure, including levels that may be common among children in lower socioeconomic income environments. Pups were exposed via dams’ drinking water from birth to post-natal day 28 to low, high or no Pb conditions. We compared gene expression of neuroinflammatory markers (study 1); and microglial mean cell body volume and mean cell body number in dentate gyrus, and dentate gyrus volume (study 2). Blood Pb levels in exposed animals at sacrifice (post-natal day 28) ranged from 2.66 to 20.31 μg/dL. Only interleukin-6 (IL6) differed between groups and reductions were dose-dependent. Microglia cell body number also differed between groups and reductions were dose-dependent. As compared with controls, microglia cell body volume was greater but highly variable in only low-dose animals; dentate gyri volumes in low- and high-dose animals were reduced. The results did not support a model of increased neuroinflammation. Instead, early chronic exposure to Pb disrupted microglia via damage to, loss of, or lack of proliferation of microglia in the developing brains of Pb-exposed animals. PMID:23598043

Exploiting Aerobic Fitness To Reduce Risk Of Hypobaric Decompression Sickness

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Gernhardt, Michael L.; Wessel, James H., III

2007-01-01

Decompression sickness (DCS) is multivariable. But we hypothesize an aerobically fit person is less likely to experience hypobaric DCS than an unfit person given that fitness is exploited as part of the denitrogenation (prebreathe, PB) process prior to an altitude exposure. Aerobic fitness is peak oxygen uptake (VO2pk, ml/kg/min). METHODS: Treadmill or cycle protocols were used over 15 years to determine VO2pks. We evaluated dichotomous DCS outcome and venous gas emboli (VGE) outcome detected in the pulmonary artery with Doppler ultrasound associated with VO2pk for two classes of experiments: 1) those with no PB or PB under resting conditions prior to ascent in an altitude chamber, and 2) PB that included exercise for some part of the PB. There were 165 exposures (mean VO2pk 40.5 +/- 7.6 SD) with 25 cases of DCS in the first protocol class and 172 exposures (mean VO2pk 41.4 +/- 7.2 SD) with 25 cases of DCS in the second. Similar incidence of the DCS (15.2% vs. 14.5%) and VGE (45.5% vs. 44.8%) between the two classes indicates that decompression stress was similar. The strength of association between outcome and VO2pk was evaluated using univariate logistic regression. RESULTS: An inverse relationship between the DCS outcome and VO2pk was evident, but the relationship was strongest when exercise was done as part of the PB (exercise PB, coef. = -0.058, p = 0.07; rest or no PB, coef. = -0.005, p = 0.86). There was no relationship between VGE outcome and VO2pk (exercise PB, coef. = -0.003, p = 0.89; rest or no PB, coef. = 0.014, p = 0.50). CONCLUSIONS: A significant change in probability of DCS was associated with fitness only when exercise was included in the denitrogenation process. We believe a fit person that exercises during PB efficiently eliminates dissolved nitrogen from tissues.

Exploiting Aerobic Fitness to Reduce Risk of Hypobaric Decompression Sickness

NASA Technical Reports Server (NTRS)

Conkin, J.; Gernhardt, M. L.; Wessel, J. H.

2007-01-01

Decompression sickness (DCS) is multivariable. But we hypothesize an aerobically fit person is less likely to experience hypobaric DCS than an unfit person given that fitness is exploited as part of the denitrogenation (prebreathe, PB) process prior to an altitude exposure. Aerobic fitness is peak oxygen uptake (VO2pk, ml/kg/min). Treadmill or cycle protocols were used over 15 years to determine VO2pks. We evaluated dichotomous DCS outcome and venous gas emboli (VGE) outcome detected in the pulmonary artery with Doppler ultrasound associated with VO2pk for two classes of experiments: 1) those with no PB or PB under resting conditions prior to ascent in an altitude chamber, and 2) PB that included exercise for some part of the PB. There were 165 exposures (mean VO2pk 40.5 plus or minus 7.6 SD) with 25 cases of DCS in the first protocol class and 172 exposures (mean VO2pk 41.4 plus or minus 7.2 SD) with 25 cases of DCS in the second. Similar incidence of the DCS (15.2% vs. 14.5%) and VGE (45.5% vs. 44.8%) between the two classes indicates that decompression stress was similar. The strength of association between outcome and VO2pk was evaluated using univariate logistic regression. An inverse relationship between the DCS outcome and VO2pk was evident, but the relationship was strongest when exercise was done as part of the PB (exercise PB, coef. = -0.058, p = 0.07; rest or no PB, coef. = -0.005, p = 0.86). There was no relationship between VGE outcome and VO2pk (exercise PB, coef. = -0.003, p = 0.89; rest or no PB, coef. = 0.014, p = 0.50). A significant change in probability of DCS was associated with fitness only when exercise was included in the denitrogenation process. We believe a fit person that exercises during PB efficiently eliminates dissolved nitrogen from tissues.

Elevated lead levels and changes in blood morphology and erythrocyte CR1 in preschool children from an e-waste area.

PubMed

Dai, Yifeng; Huo, Xia; Zhang, Yu; Yang, Tian; Li, Minghui; Xu, Xijin

2017-08-15

Improper dismantling and combustion of electronic waste (e-waste) may release persistent organic pollutants and heavy metals that possess potential risk for human health. Lead (Pb) is carried through the circulatory system by erythrocytes and is known to alter the functions of hematopoietic and immune systems. The aim of the study was to investigate the effect of Pb exposure on blood morphology and erythrocyte complement receptor 1 (CR1) levels as related to immunologic function in preschool children. We recruited 484 preschool children, 2- to 6-years of age, among whom 332 children were from Guiyu, a typical and primitive e-waste processing area, and 152 children from Haojiang (reference area). Results showed that the blood Pb level (BPb) and erythrocyte Pb level (EPb) of exposed children were significantly higher, but, the mean corpuscular hemoglobin concentration (MCHC) and erythrocyte CR1 levels were significantly lower than reference children. Elevated EPb and BPb was related to disadvantageous changes in hematocrit (HCT), mean corpuscular volume (MCV), hemoglobin (HGB), mean corpuscular hemoglobin (MCH), and MCHC, respectively, in children from the e-waste recycling area. Furthermore, in the high Pb-exposed group, the Pb toxicity of erythrocytes was more significant compared to the low Pb-exposed group in e-waste-exposed children. Combine with the BPb and EPb would be better to evaluating the Pb toxicity of erythrocytes. Compared to low Pb exposure, high BPb and EPb were associated with lower erythrocyte CR1 expression in all children. Our data suggests that elevated Pb levels result in adverse changes in blood morphology, hemoglobin synthesis and CR1 expression, which might be a non-negligible threat to erythrocyte immunity development in local preschool children. It is therefore imperative for any intervention to control the Pb exposure of children and actively educate adults to raise their environmental awareness of potential e-waste pollution during the recycling process. Copyright © 2017 Elsevier B.V. All rights reserved.

Neurobehavioral impairments caused by developmental imidacloprid exposure in zebrafish.

PubMed

Crosby, Emily B; Bailey, Jordan M; Oliveri, Anthony N; Levin, Edward D

2015-01-01

Neonicotinoid insecticides are becoming more widely applied as organophosphate (OP) insecticides are decreasing in use. Because of their relative specificity to insect nicotinic receptors, they are thought to have reduced risk of neurotoxicity in vertebrates. However, there is scant published literature concerning the neurobehavioral effects of developmental exposure of vertebrates to neonicotinoids. Using zebrafish, we investigated the neurobehavioral effects of developmental exposure to imidacloprid, a prototypic neonicotinoid pesticide. Nicotine was also administered for comparison. Zebrafish were exposed via immersion in aqueous solutions containing 45 μM or 60 μM of imidacloprid or nicotine (or vehicle control) from 4h to 5d post fertilization. The functional effects of developmental exposure to both imidacloprid and nicotine were assessed in larvae using an activity assay and during adolescence and adulthood using a battery of neurobehavioral assays, including assessment of sensorimotor response and habituation in a tactile startle test, novel tank swimming, and shoaling behavior. In larvae, developmental imidacloprid exposure at both doses significantly decreased swimming activity. The 5D strains of zebrafish were more sensitive to both nicotine and imidacloprid than the AB* strain. In adolescent and adult fish, developmental exposure to imidacloprid significantly decreased novel tank exploration and increased sensorimotor response to startle stimuli. While nicotine did not affect novel tank swimming, it increased sensorimotor response to startle stimuli at the low dose. No effects of either compound were found on shoaling behavior or habituation to a startling stimulus. Early developmental exposure to imidacloprid has both early-life and persisting effects on neurobehavioral function in zebrafish. Its developmental neurotoxicity should be further investigated. Copyright © 2015 Elsevier Inc. All rights reserved.

Geographic clustering of elevated blood heavy metal levels in pregnant women.

PubMed

King, Katherine E; Darrah, Thomas H; Money, Eric; Meentemeyer, Ross; Maguire, Rachel L; Nye, Monica D; Michener, Lloyd; Murtha, Amy P; Jirtle, Randy; Murphy, Susan K; Mendez, Michelle A; Robarge, Wayne; Vengosh, Avner; Hoyo, Cathrine

2015-10-09

Cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) exposure is ubiquitous and has been associated with higher risk of growth restriction and cardiometabolic and neurodevelopmental disorders. However, cost-efficient strategies to identify at-risk populations and potential sources of exposure to inform mitigation efforts are limited. The objective of this study was to describe the spatial distribution and identify factors associated with Cd, Pb, Hg, and As concentrations in peripheral blood of pregnant women. Heavy metals were measured in whole peripheral blood of 310 pregnant women obtained at gestational age ~12 weeks. Prenatal residential addresses were geocoded and geospatial analysis (Getis-Ord Gi* statistics) was used to determine if elevated blood concentrations were geographically clustered. Logistic regression models were used to identify factors associated with elevated blood metal levels and cluster membership. Geospatial clusters for Cd and Pb were identified with high confidence (p-value for Gi* statistic <0.01). The Cd and Pb clusters comprised 10.5 and 9.2 % of Durham County residents, respectively. Medians and interquartile ranges of blood concentrations (μg/dL) for all participants were Cd 0.02 (0.01-0.04), Hg 0.03 (0.01-0.07), Pb 0.34 (0.16-0.83), and As 0.04 (0.04-0.05). In the Cd cluster, medians and interquartile ranges of blood concentrations (μg/dL) were Cd 0.06 (0.02-0.16), Hg 0.02 (0.00-0.05), Pb 0.54 (0.23-1.23), and As 0.05 (0.04-0.05). In the Pb cluster, medians and interquartile ranges of blood concentrations (μg/dL) were Cd 0.03 (0.02-0.15), Hg 0.01 (0.01-0.05), Pb 0.39 (0.24-0.74), and As 0.04 (0.04-0.05). Co-exposure with Pb and Cd was also clustered, the p-values for the Gi* statistic for Pb and Cd was <0.01. Cluster membership was associated with lower education levels and higher pre-pregnancy BMI. Our data support that elevated blood concentrations of Cd and Pb are spatially clustered in this urban environment compared to the surrounding areas. Spatial analysis of metals concentrations in peripheral blood or urine obtained routinely during prenatal care can be useful in surveillance of heavy metal exposure.

Milk and Dairy Products Intake Is Associated with Low Levels of Lead (Pb) in Workers highly Exposed to the Metal.

PubMed

Gomes, Willian Robert; Devóz, Paula Pícoli; Araújo, Marília Ladeira; Batista, Bruno Lemos; Barbosa, Fernando; Barcelos, Gustavo Rafael Mazzaron

2017-07-01

Lead (Pb) is a toxic metal, frequently associated with occupational exposure, due to its widespread use in industry and several studies have shown high Pb levels in workers occupationally exposed to the metal. The aim of this study was to evaluate the influence of milk and dairy products (MDP) on Pb levels in blood (B-Pb), plasma (P-Pb), and urine (U-Pb), in workers from automotive battery industries in Brazil. The study included 237 male workers; information concerning diet and lifestyle were gathered through a questionnaire, and B-Pb, P-Pb, and U-Pb were determined by ICP-MS. Mean B-Pb, P-Pb, and U-Pb were 21 ± 12, 0.62 ± 0.73 μg/dL, and 39 ± 47 μg/g creatinine, respectively. Forty three percent of participants declared consuming ≤3 portions/week of MDP (classified as low-MDP intake), while 57% of individuals had >3portions/week of MDP (high-MDP intake). B-Pb and P-Pb were correlated with working time (r s  = 0.21; r s  = 0.20; p < 0.010). Multivariable linear regressions showed a significant influence of MDP intake on B-Pb (β = -0.10; p = 0.012) and P-Pb (β = -0.16; p < 0.010), while no significance was seen on U-Pb. Our results suggest that MDP consumption may modulate Pb levels in individuals highly exposed to the metal; these findings may be due to the Pb-Ca interactions, since the adverse effects of Pb are partially based on its interference with Ca metabolism and proper Ca supplementation may help to reduce the adverse health effects induced by Pb exposure.

The relationship between environmental exposure to cadmium and lead and blood selenium concentration in randomly selected population of children inhabiting industrial regions of Silesian Voivodship (Poland).

PubMed

Gać, P; Pawlas, N; Poręba, R; Poręba, M; Pawlas, K

2014-06-01

This study aimed at determining the relationship between environmental exposure to lead (Pb) and cadmium (Cd) and blood selenium (Se) concentration in randomly selected population of children inhabiting the industrial regions of Silesian Voivodship, Poland. The study was conducted on a group of consecutive randomly selected 349 children aged below 15 years and inhabiting the industrial regions in Upper Silesia. The examined variables included whole blood Cd concentration (Cd-B), whole blood Pb concentration (Pb-B) and whole blood Se concentration (Se-B). The concentration of Cd-B, Pb-B and Se-B in the studied group of children amounted to 0.26 ± 0.14, 37.62 ± 25.30 and 78.31 ± 12.82 μg/L, respectively. In the entire examined group a statistically significant negative linear relationship was noted between Pb-B and Se-B (r = -0.12, p < 0.05). Also, a statistically insignificant negative correlation was detected between Cd-B and Se-B (r = -0.02, p > 0.05) and a statistically insignificant positive correlation between Pb-B and Cd-B (r = 0.08, p > 0.05). A multivariate backward stepwise regression analysis demonstrated that in the studied group of children higher Pb-B and a more advanced age-represented independent risk factors for a decreased Se-B. Environmental exposure to Pb may represent an independent risk factor for Se deficit in blood of the studied population of children. In children, the lowered Se-B may create one of the mechanisms in which Pb unfavourably affects human body. © The Author(s) 2014.

Lead exposure results in hearing loss and disruption of the cochlear blood-labyrinth barrier and the protective role of iron supplement.

PubMed

Liu, Xinqin; Zheng, Gang; Wu, Yongxiang; Shen, Xuefeng; Jing, Jinfei; Yu, Tao; Song, Han; Chen, Jingyuan; Luo, Wenjing

2013-12-01

This study was designed to investigate the impact of lead (Pb(2+)) on the auditory system and its molecular mechanisms. Pb(AC)2 was administrated to male SD rats aged 21-22 d for 8 weeks at a dose of 300ppm. Male guinea pigs were also administrated with 50mg/kg Pb(AC)2 two times a week for 8 weeks. The auditory nerve-brainstem evoked responses (ABR) was recorded and the morphological changes of the outer hair cells (OHCs) were observed with Phallodin-FITC staining. In addition, the integrity of the blood-labyrinth barrier was observed by TEM and the expression of tight junction proteins (TJPs) in the cochlear stria vascularis was determined by immunofluorescence. Our results showed that Pb(2+) exposure resulted in increased ABR threshold in both rats and guinea pigs. Abnormal shapes and loss of OHCs were found in the cochlear basilar membrane following the Pb(2+) exposure. TEM study showed that the tight junctions between the endothelial cells and the border cells were lost and disrupted. Down-regulation of the occludin, ZO-1 and claudin-5 in the stria vascularis suggested that the increased permeability of the blood-labyrinth barrier may attribute to the Pb(2+)-induced decrease of TJPs' expression. Additionally, Fe(2+) supplement partly reversed the Pb(2+)-induced hearing loss and down-regulation of TJPs. Taken together, these data indicate that the disruption of blood-labyrinth barrier by down-regulating the expression of TJPs plays a role in the Pb(2+)-induced hearing loss, and Fe(2+) supplement protects the auditory system against Pb(2+)-induced toxicity and may have significant clinical implications. Copyright © 2013 Elsevier Inc. All rights reserved.

Relation of lead exposure to sediment ingestion in mute swans on the Chesapeake Bay, USA

USGS Publications Warehouse

Beyer, W.N.; Day, D.; Morton, Alexandra; Pachepsky, Y.

1998-01-01

Forty-two mute swans (Cygnus olor ) were collected from unpolluted portions of central Chesapeake Bay in spring 1995. Their intestinal digesta were analyzed for 13 metals (Al, B, Ba, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Sr, V, Zn) and for acid-insoluble ash, a marker of sediment. Because metal concentrations in digesta depend on recent exposure, they are appropriate for evaluating local contamination. Swan livers and sediment samples also were analyzed for the same metals. Group method of data handling demonstrated that the digesta Al was the best predictor of digesta Pb, and that adding concentrations of other metals as predictors did not improve the accuracy of the estimates of Pb concentrations from Al concentrations. The r2 of the equation relating the log of digesta Pb to the log of digesta Al was 0.86, whereas the r2 of the equation relating the log of digesta Pb to the log of digesta acid-insoluble ash was 0.50. Sediment ingestion was critical in determining exposure to Pb, as well as to some of the other metals, and should be considered in ecotoxicological risk assessments of waterfowl. The mean of 7.4% acid-insoluble ash in the digesta corresponded to an estimated 3.2% sediment in the diet. The Pb concentrations in the digesta were 2-3 times the concentration that would have been predicted from sediment Pb concentrations; presumably the swans had ingested clays high in Pb that had settled on the vegetation. The swans were not thought to have been exposed to high Cu concentrations but they had hepatic Cu concentrations that would be considered very high if found in other species.

Pyridostigmine bromide modulates topical irritant-induced cytokine release from human epidermal keratinocytes and isolated perfused porcine skin.

PubMed

Monteiro-Riviere, Nancy A; Baynes, Ronald E; Riviere, Jim E

2003-02-01

Gulf War personnel were given pyridostigmine bromide (PB) as a prophylactic treatment against organophosphate nerve agent exposure, and were exposed to the insecticide permethrin and the insect repellent N,N-diethyl-m-toluamide (DEET). The purpose of this study was to assess the effects of PB to modulate release of inflammatory biomarkers after topical chemical exposure to chemical mixtures containing permethrin and DEET applied in ethanol or water vehicles. Treatments were topically applied to isolated perfused porcine skin flaps (IPPSFs). Concentrations of interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)) were assayed in perfusate to probe for potential inflammatory effects after complex mixture application. IPPSFs (n=4/treatment) were topically dosed with mixtures of permethrin, DEET, and permethrin/DEET, in ethanol. Each treatment was repeated with perfusate spiked with 50 ng/ml of PB. Perfusate was also spiked with 30 ng/ml diisopropylfluorophosphate to simulate low level organophosphate nerve agent exposure. Timed IPPSF venous effluent samples (0.5,1,2,4, and 8 h) were assayed by ELISA for IL-8 and TNF-alpha and by EIA for PGE(2). Overall, PB infusion caused a decrease or IL-8 and PGE(2) release. Effects on TNF-alpha were vehicle dependent. To probe the potential mechanism of this PB effect, human epidermal keratinocyte HEK cell cultures were exposed to permethrin DEET permethrin/DEET, with and without PB in DMSO. IL-8 was assayed at 1, 2, 4, 8, 12 and 24 h. PB suppressed IL-8 in permethrin and ethanol treatment from 4 to 24 h confirming the IPPSF results. In conclusion, these studies suggest that systemic exposure to PB suppressed IL-8 release at multiple time points in two skin model systems. This interaction merits further study.

Perinatal lead (Pb) exposure results in sex and tissue-dependent adult DNA methylation alterations in murine IAP transposons.

PubMed

Montrose, L; Faulk, C; Francis, J; Dolinoy, D C

2017-10-01

Epidemiological and animal data suggest that adult chronic disease is influenced by early-life exposure-induced changes to the epigenome. Previously, we observed that perinatal lead (Pb) exposure results in persistent murine metabolic- and activity-related effects. Using phylogenetic and DNA methylation analysis, we have also identified novel intracisternal A particle (IAP) retrotransposons exhibiting regions of variable methylation as candidate loci for environmental effects on the epigenome. Here, we now evaluate brain and kidney DNA methylation profiles of four representative IAPs in adult mice exposed to human physiologically relevant levels of Pb two weeks prior to mating through lactation. When IAPs across the genome were evaluated globally, average (sd) methylation levels were 92.84% (3.74) differing by tissue (P < 0.001), but not sex or dose. By contrast, the four individual IAPs displayed tissue-specific Pb and sex effects. Medium Pb-exposed mice had 3.86% less brain methylation at IAP 110 (P < 0.01), while high Pb-exposed mice had 2.83% less brain methylation at IAP 236 (P = 0.01) and 1.77% less at IAP 506 (P = 0.05). Individual IAP DNA methylation differed by sex for IAP 110 in the brain and kidney, IAP 236 in the kidney, and IAP 1259 in the kidney. Using Tomtom, we identified three binding motifs that matched to each of our novel IAPs impacted by Pb, one of which (HMGA2) has been linked to metabolic-related conditions in both mice and humans. Thus, these recently identified IAPs display tissue-specific environmental lability as well as sex-specific differences supporting an epigenetic link between early exposure to Pb and later-in-life health outcomes. Environ. Mol. Mutagen. 58:540-550, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Indicative and complementary effects of human biological indicators for heavy metal exposure assessment.

PubMed

Xing, Ruiya; Li, Yonghua; Zhang, Biao; Li, Hairong; Liao, Xiaoyong

2017-10-01

Although human biological indicators have been widely utilized for biomonitoring environmental pollutants in health exposure assessment, the relationship between internal and external exposure has not yet been adequately established. In this study, we collected and analyzed 61 rice, 56 pepper, and 58 soil samples, together with 107 hair, 107 blood, and 107 urine samples from residents living in selected intensive mining areas in China. Concentrations of most of the four elements considered (Pb, Cd, Hg, and Se) exceeded national standards, implying high exposure risk in the study areas. Regression analysis also revealed a correlation (0.33, P < 0.001) between the concentration of Pb in soil and that in human hair (as well as in human blood); to some extent, Pb content in hair and blood could therefore be used to characterize external Pb exposure. The correlation between Hg in rice and in human hair (up to 0.5, P < 0.001) further confirmed a significant indicative effect of human hair for Hg exposure. A significant correlation was also noted between concentrations of some elements in different human samples, for example, between Hg in hair and blood (0.641, P < 0.01) and between Cd in urine and blood (0.339, P < 0.01). To some extent, there could thus be mutual reflectance of the same heavy metal in different samples, with the possibility for complementary use in assessing heavy metal exposure.

Melatonin ameliorates oxidative damage induced by maternal lead exposure in rat pups.

PubMed

Bazrgar, Maryam; Goudarzi, Iran; Lashkarbolouki, Taghi; Elahdadi Salmani, Mahmoud

2015-11-01

During the particular period of cerebellum development, exposure to lead (Pb) decreases cerebellum growth and can result in selective loss of neurons. The detection and prevention of Pb toxicity is a major international public health priorities. This research study was conducted to evaluate the effects of melatonin, an effective antioxidant and free radical scavenger, on Pb induced neurotoxicity and oxidative stress in the cerebellum. Pb exposure was initiated on gestation day 5 with the addition of daily doses of 0.2% lead acetate to distilled drinking water and continues until weaning. Melatonin (10mg/kg) was given once daily at the same time. 21 days after birth, several antioxidant enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase (GPx) were assayed. Thiobarbituric acid reactive substance (TBARS) levels were measured as a marker of lipid peroxidation. Rotarod and locomotor activity tests were performed on postnatal days (PDs) 31-33 and a histological study was performed after completion of behavioral measurements on PD 33. The results of the present work demonstrated that Pb could induce lipid peroxidation, increase TBARS levels and decrease GPx and SOD activities in the rat cerebellum. We also observed that Pb impaired performance on the rotarod and locomotor activities of rats. However, treatment with melatonin significantly attenuated the motoric impairment and lipid peroxidation process and restored the levels of antioxidants. Histological analysis indicated that Pb could decrease Purkinje cell count and melatonin prevented this toxic effect. These results suggest that treatment with melatonin can improve motor deficits and oxidative stress by protecting the cerebellum against Pb toxicity. Copyright © 2015 Elsevier Inc. All rights reserved.

TRPC1 is involved in Ca²⁺ influx and cytotoxicity following Pb²⁺ exposure in human embryonic kidney cells.

PubMed

Zhang, Hongmei; Li, Wenjun; Xue, Yong; Zou, Fei

2014-08-17

Lead (Pb(2+)) is a divalent heavy metal ion which causes severe damage to almost all life forms and is therefore considered a notorious toxicant. Exposure to Pb(2+) is associated with poor cognitive development in children at relatively low levels that previously were thought to be safe. The mechanism through which Pb(2+) enters cells, however, is unclear. Previous studies have showed that Ca(2+) release-activated Ca(2+) protein 1 (Orai1), a component of store-operated Ca(2+) channels (SOCs), contributes to Pb(2+) cellular entry. Canonical transient receptor potential (TRPC1) channel 1 is a transient receptor potential (TRP) channel which is sometimes referred to as a SOC. The present study was designed to investigate the role of TRPC1 in Pb(2+) entry and toxicity in human embryonic kidney cells (HEK293). Additionally, changes in intracellular Ca(2+) concentration were determined through Fluo-4 and Mag-fluo-4 fluorescent Ca(2+) imaging. Following Pb(2+) exposure, there was a dose-dependent decrease in cell viability. Overexpression of TRPC1 increased Pb(2+)-induced cell death, while knockdown of this channel attenuated cell death. There was increased entry of Pb(2+), as measured by inductively coupled plasma mass spectrometry (ICP-MS), following overexpression of TRPC1. Conversely, knockdown of TRPC1 led to a decrease in Pb(2+) influx. Down-regulation of STIM1 by RNA interference attenuated the Pb(2+) influx, and transfection with a mutant STIM1, which could not gate TRPC1, had a similar effect. Co-transfection of mutant STIM1 and mutant TRPC1, which restore the electrostatic interaction between STIM1 and TRPC1, resumed Pb(2+) entry in HEK293 cells. Down-regulation of TRPC1 by RNA interference decreased Ca(2+) influx whilst its overexpression increased Ca(2+) entry in HEK293 cells. These results suggest that TRPC1 is involved in the cytotoxicity and entry of Pb(2+) through molecular interactions with STIM1 and subsequent Ca(2+) influx in HEK293 cells. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Evaluation of the use of salivary lead levels as a surrogate of blood lead or plasma lead levels in lead exposed subjects.

PubMed

Barbosa, Fernando; Corrêa Rodrigues, Maria Heloísa; Buzalaf, Maria R; Krug, Francisco J; Gerlach, Raquel F; Tanus-Santos, José Eduardo

2006-10-01

We conducted a study to evaluate the use of parotid salivary lead (Pb-saliva) levels as a surrogate of the blood lead (Pb-B) or plasma lead levels (Pb-P) to diagnose lead exposure. The relationship between these biomarkers was assessed in a lead exposed population. Pb-saliva and Pb-P were determined by inductively coupled plasma mass spectrometry, while in whole blood lead was determined by graphite furnace atomic absorption spectrometry. We studied 88 adults (31 men and 57 women) from 18 to 60 years old. Pb-saliva levels varied from 0.05 to 4.4 microg/l, with a mean of 0.85 microg/l. Blood lead levels varied from 32.0 to 428.0 microg/l in men (mean 112.3 microg/l) and from 25.0 to 263.0 microg/l (mean 63.5 microg/l) in women. Corresponding Pb-Ps were 0.02-2.50 microg/l (mean 0.77 microg/l) and 0.03-1.6 microg/l (mean 0.42 microg/l) in men and women, respectively. A weak correlation was found between Log Pb-saliva and Log Pb-B (r=0.277, P<0.008), and between Log Pb-saliva and Log Pb-P (r=0.280, P=0.006). The Pb-saliva/Pb-P ratio ranged from 0.20 to 18.0. Age or gender does not affect Pb-saliva levels or Pb-saliva/Pb-P ratio. Taken together, these results suggest that salivary lead may not be used as a biomarker to diagnose lead exposure nor as a surrogate of plasma lead levels at least for low to moderately lead exposed population.

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

Song, Han; Zheng, Gang; Liu, Yang

As the structural basis of blood-cerebrospinal fluid barrier (BCB), epithelial cells in the choroid plexus (CP) are targets for lead (Pb). Pb is known to accumulate in the CP; however, the mechanism of Pb uptake in the choroidal epithelial cells remains unknown. Recently, hemichannels of Connexin 43 (Cx43), the most ubiquitously expressed gap junction proteins in the CP, were found to be important pathways for many substances. This study was designed to investigate the roles of Cx43 in Pb uptake in the epithelial cells. Autometallography was used to outline Pb's subcellular location, and the characteristics of Pb transport into CPmore » cells, including concentration- and time-dependence were analyzed by atomic absorption spectroscopy. Knockdown/overexpression of Cx43 with transient siRNA/plasmids transfections before Pb exposure diminished/increased the Pb accumulation. In the Z310 cell-based doxycycline-inducible Cx43 expression cell line (iZCx43), doxycycline induced a significant increase (3-fold) in Pb uptake, corresponding to the increased Cx43 levels. Activation of Cx43 hemichannels by reduced serum conditions caused an increase of Pb concentrations. Cx43-induced Pb uptake was attenuated after blockage of Cx43 hemichannels with its inhibitor, carbenoxolone. Additionally, down-regulation of Cx43 protein levels by Pb exposure paralleled cellular Pb concentrations in the time study. Concomitantly, expressions of phosphor-Src and phosphor-Erk were both significantly increased by Pb. However, inactivation of Erk, not Src pathway, reversed Pb-induced downregulation of Cx43. Taken together, these data establish that Pb can accumulate in the BCB and validate the role of Cx43 hemichannel in Pb uptake and its regulations through Erk phosphorylation. - Highlights: • Pb is sequestrated in choroid plexus both in vivo and in vitro. • Cx43 knockdown/overexpression prevents/increases Pb accumulations. • Cx43 hemichannels are required for Pb uptake. • Pb-induced Erk activation causes reduction of Cx43.« less

Occupational and environmental lead exposure to adolescent workers in battery recycling workshops.

PubMed

Kazi, Tasneem Gul; Shah, Faheem; Afridi, Hassan Imran; Naeemullah

2015-12-01

Lead (Pb), as other environmental neurotoxicant substances, has the capability to interfere with many biochemical events present in cells throughout the body. In the present study, the environmental and occupational exposure to Pb has been assessed by analyzing the scalp hair samples of male adolescents aged 12-15 years, who have worked for the last 12-36 months in Pb battery recycling workshops (BRWs). For comparative purposes, gender and age-matched subjects living in the vicinity of recycling workshops as well as in areas without industrial activity were used as controls. The scalp hair samples were oxidized by acid in a microwave oven prior to determination of Pb by electrothermal atomic absorption spectrometry. The results indicated that both workers and nonworking exposed subjects had higher levels of Pb than nonexposed controls. The contents of Pb in scalp hair of adolescent workers in the present study were compared with those reported in other studies. © The Author(s) 2013.

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...

Early life lead exposure causes gender-specific changes in the DNA methylation profile of DNA extracted from dried blood spots

PubMed Central

Sen, Arko; Heredia, Nicole; Senut, Marie-Claude; Hess, Matthew; Land, Susan; Qu, Wen; Hollacher, Kurt; Dereski, Mary O; Ruden, Douglas M

2015-01-01

Aims In this paper, we tested the hypothesis that early life lead (Pb) exposure associated DNA methylation (5mC) changes are dependent on the sex of the child and can serve as biomarkers for Pb exposure. Methods In this pilot study, we measured the 5mC profiles of DNA extracted from dried blood spots (DBS) in a cohort of 43 children (25 males and 18 females; ages from 3 months to 5 years) from Detroit. Result & Discussion We found that the effect of Pb-exposure on the 5-mC profiles can be separated into three subtypes: affected methylation loci which are conserved irrespective of the sex of the child (conserved); affected methylation loci unique to males (male-specific); and affected methylation loci unique to females (female-specific). PMID:26077427

DEVELOPMENTAL DISRUPTION OF THYROID HORMONE: CORRELATIONS WITH HEARING DYSFUNCTION IN RATS.

EPA Science Inventory

A manuscript presents evidence that thyroxine (T4) is a good biomarker-of-effect for developmental neurotoxicity associated with exposure to environmental thyrotoxicants. A major uncertainty in assessing the risks of developmental exposure to thyrotoxicants is the lack of a clear...

Arsenic and lead contamination in urban soils of Villa de la Paz (Mexico) affected by historical mine wastes and its effect on children's health studied by micronucleated exfoliated cells assay.

PubMed

Gamiño-Gutiérrez, Sandra P; González-Pérez, C Ivonne; Gonsebatt, María E; Monroy-Fernández, Marcos G

2013-02-01

Environmental geochemical and health studies were carried out in urban areas of Villa de la Paz, S.L.P. (Mexico), where mining activities have been developed for more of 200 years, leading to the pollution of surface soil by arsenic and heavy metals (Pb, Cd, Cu, Zn). The analysis of urban soils to determine total and bioaccessibility concentrations of As and Pb, demonstrated a combined contribution of the natural and anthropogenic concentrations in the site, at levels higher than the environmental guideline values that provoke a human health risk. Contour soil mapping confirmed that historical mine waste deposits without environmental control measures, are the main source of pollution soil by As and Pb in the site. Exposure (Pb in blood and As in urine) and effect (micronucleated exfoliated cells assay) biological monitoring were then carried out in the childhood population of the site and in a control site. The exposure biological monitoring demonstrated that at least 20-30 % of children presented Pb and As exposure values higher than the national and international maximum intervention values. The effect biomonitoring by MEC assay confirmed that there is a genotoxic damage in local childhood population that could be associated with the arsenic exposure in the site.

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.

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

PubMed

Karri, Venkatanaidu; Schuhmacher, Marta; Kumar, Vikas

2016-12-01

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

Exposures of lead to adolescent workers in battery recycling workshops and surrounding communities.

PubMed

Shah, Faheem; Kazi, Tasneem Gul; Afridi, Hassan Imran; Naeemullah; Arain, Sadaf Sadia

2012-11-01

In the present study, the environmental and occupational exposure of lead (Pb) has been assessed by analyzing the whole-blood samples of early adolescents (boys) aged 12-15 years working for the past 1-3 years in battery recycling workshops (BRW). For comparative purpose, boys of the same age group residing in the vicinity of BRW (exposed non-workers) and who lived in domestic areas devoid of any industrial activity (referents boys) were selected. The blood samples were analyzed for Pb, along with biochemical parameters of blood. Both biological samples were oxidized by acid in a microwave oven before determination of Pb by graphite furnace atomic absorption spectrometry. The mean value of Pb concentration in blood samples of working boys was threefold higher as compared with referent boys. The significant negative correlations of blood Pb level with % Hb (r=-0.862) were observed in working boys.

A REVIEW OF HUMAN STUDIES ON THE REPRODUCTIVE AND DEVELOPMENTAL EFFECTS OF PESTICIDE EXPOSURE

EPA Science Inventory

Many pesticides cxause reproductive or developmental toxicity at high doses in animal models, but effects in humans at environmental exposure levels are difficult to assess. Human data on reproductive and developmental outcomes for currently used pesticides may help to define ris...

Protection by pyridostigmine bromide of marmoset hemi-diaphragm acetylcholinesterase activity after soman exposure.

PubMed

Haigh, Julian R; Adler, Michael; Apland, James P; Deshpande, Sharad S; Barham, Charles B; Desmond, Patrick; Koplovitz, Irwin; Lenz, David E; Gordon, Richard K

2010-09-06

Pyridostigmine bromide (PB) was approved by the U.S. Food and Drug Administration (FDA) in 2003 as a pretreatment in humans against the lethal effects of the irreversible nerve agent soman (GD). Organophosphate (OP) chemical warfare agents such as GD exert their toxic effects by inhibiting acetylcholinesterase (AChE) from terminating the action of acetylcholine at postsynaptic sites in cholinergic nerve terminals (including crucial peripheral muscle such as diaphragm). As part of the post-marketing approval of PB, the FDA required (under 21CFR314, the "two animal rule") the study of a non-human primate model (the common marmoset Callithrix jacchus jacchus) to demonstrate increased survival against lethal GD poisoning, and protection of physiological hemi-diaphragm function after PB pretreatment and subsequent GD exposure. Marmosets (male and female) were placed in the following experimental groups: (i) control (saline pretreatment only), (ii) low dose PB (12.5 microg/kg), or (iii) high dose (39.5 microg/kg) PB. Thirty minutes after the PB dose, animals were challenged with either saline (control) or soman (GD, 45 microg/kg), followed 1 min later by atropine (2mg/kg) and 2-PAM (25mg/kg). After a further 16 min, animals were euthanized and the complete diaphragm removed; the right hemi-diaphragm was frozen immediately at -80 degrees C, and the left hemi-diaphragm was placed in a tissue bath for 4h (to allow for decarbamylation to occur), then frozen. AChE activities were determined using the automated WRAIR cholinesterase assay. Blood samples were collected for AChE activities prior to PB, before GD challenge, and after sacrifice. RBC-AChE was inhibited by approximately 18% and 50% at the low and high doses of PB, respectively, compared to control (baseline) activity. In the absence of PB pretreatment, the inhibition of RBC-AChE by GD was 98%. The recovery of hemi-diaphragm AChE activity after the 4h wash period (decarbamylation) was approximately 8% and 17%, at the low and high PB doses, respectively, compared with the baseline (control) AChE activity prior to PB pretreatment or soman exposure. The results suggest that PB pretreatment protects a critical fraction of AChE activity in the marmoset diaphragm, which is sufficient to allow the animal to breathe despite exposure to a dose of soman that is lethal in unprotected animals. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Perinatal exposure to lead (Pb) induces ultrastructural and molecular alterations in synapses of rat offspring.

PubMed

Gąssowska, Magdalena; Baranowska-Bosiacka, Irena; Moczydłowska, Joanna; Frontczak-Baniewicz, Małgorzata; Gewartowska, Magdalena; Strużyńska, Lidia; Gutowska, Izabela; Chlubek, Dariusz; Adamczyk, Agata

2016-12-12

Lead (Pb), environmentally abundant heavy-metal pollutant, is a strong toxicant for the developing central nervous system. Pb intoxication in children, even at low doses, is found to affect learning and memorizing, with devastating effects on cognitive function and intellectual development. However, the precise mechanism by which Pb impairs synaptic plasticity is not fully elucidated. The purpose of this study was to investigate the effect of pre- and neonatal exposure to low dose of Pb (with Pb concentrations in whole blood below 10μg/dL) on the synaptic structure and the pre- and postsynaptic proteins expression in the developing rat brain. Furthermore, the level of brain-derived neurotrophic factor (BDNF) was analyzed. Pregnant female Wistar rats received 0.1% lead acetate (PbAc) in drinking water from the first day of gestation until weaning of the offspring, while the control animals received drinking water. During the feeding of pups, mothers from the Pb-group were continuously receiving PbAc. Pups of both groups were weaned at postnatal day 21 and then until postnatal day 28 received only drinking water. 28-day old pups were sacrificed and the ultrastructural changes as well as expression of presynaptic (VAMP1/2, synaptophysin, synaptotagmin-1, SNAP25, syntaxin-1) and postsynaptic (PSD-95) proteins were analyzed in: forebrain cortex, cerebellum and hippocampus. Our data revealed that pre- and neonatal exposure to low dose of Pb promotes pathological changes in synapses, including nerve endings swelling, blurred and thickened synaptic cleft structure as well as enhanced density of synaptic vesicles in the presynaptic area. Moreover, synaptic mitochondria were elongated, swollen or shrunken in Pb-treated animals. These structural abnormalities were accompanied by decrease in the level of key synaptic proteins: synaptotagmin-1 in cerebellum, SNAP25 in hippocampus and syntaxin-1 in cerebellum and hippocampus. In turn, increased level of synaptophysin was noticed in the cerebellum, while the expression of postsynaptic PSD-95 was significantly decreased in forebrain cortex and cerebellum, and raised in hippocampus. Additionally, we observed the lower level of BDNF in all brain structures in comparison to control animals. In conclusion, perinatal exposure to low doses of Pb caused pathological changes in nerve endings associated with the alterations in the level of key synaptic proteins. All these changes can lead to synaptic dysfunction, expressed by the impairment of the secretory mechanism and thereby to the abnormalities in neurotransmission as well as to the neuronal dysfunction. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of Polar Bear and Killer Whale Derived Contaminant Cocktails on Marine Mammal Immunity.

PubMed

Desforges, Jean-Pierre; Levin, Milton; Jasperse, Lindsay; De Guise, Sylvain; Eulaers, Igor; Letcher, Robert J; Acquarone, Mario; Nordøy, Erling; Folkow, Lars P; Hammer Jensen, Trine; Grøndahl, Carsten; Bertelsen, Mads F; St Leger, Judy; Almunia, Javier; Sonne, Christian; Dietz, Rune

2017-10-03

Most controlled toxicity studies use single chemical exposures that do not represent the real world situation of complex mixtures of known and unknown natural and anthropogenic substances. In the present study, complex contaminant cocktails derived from the blubber of polar bears (PB; Ursus maritimus) and killer whales (KW; Orcinus orca) were used for in vitro concentration-response experiments with PB, cetacean and seal spp. immune cells to evaluate the effect of realistic contaminant mixtures on various immune functions. Cytotoxic effects of the PB cocktail occurred at lower concentrations than the KW cocktail (1 vs 16 μg/mL), likely due to differences in contaminant profiles in the mixtures derived from the adipose of each species. Similarly, significant reduction of lymphocyte proliferation occurred at much lower exposures in the PB cocktail (EC 50 : 0.94 vs 6.06 μg/mL; P < 0.01), whereas the KW cocktail caused a much faster decline in proliferation (slope: 2.9 vs 1.7; P = 0.04). Only the KW cocktail modulated natural killer (NK) cell activity and neutrophil and monocyte phagocytosis in a concentration- and species-dependent manner. No clear sensitivity differences emerged when comparing cetaceans, seals and PB. Our results showing lower effect levels for complex mixtures relative to single compounds suggest that previous risk assessments underestimate the effects of real world contaminant exposure on immunity. Our results using blubber-derived contaminant cocktails add realism to in vitro exposure experiments and confirm the immunotoxic risk marine mammals face from exposure to complex mixtures of environmental contaminants.

Behavioral, cellular and molecular maladaptations covary with exposure to pyridostigmine bromide in a rat model of gulf war illness pain.

PubMed

Cooper, B Y; Flunker, L D; Johnson, R D; Nutter, T J

2018-08-01

Many veterans of Operation Desert Storm (ODS) struggle with the chronic pain of Gulf War Illness (GWI). Exposure to insecticides and pyridostigmine bromide (PB) have been implicated in the etiology of this multisymptom disease. We examined the influence of 3 (DEET (N,N-diethyl-meta-toluamide), permethrin, chlorpyrifos) or 4 GW agents (DEET, permethrin, chlorpyrifos, pyridostigmine bromide (PB)) on the post-exposure ambulatory and resting behaviors of rats. In three independent studies, rats that were exposed to all 4 agents consistently developed both immediate and delayed ambulatory deficits that persisted at least 16 weeks after exposures had ceased. Rats exposed to a 3 agent protocol (PB excluded) did not develop any ambulatory deficits. Cellular and molecular studies on nociceptors harvested from 16WP (weeks post-exposure) rats indicated that vascular nociceptor Na v 1.9 mediated currents were chronically potentiated following the 4 agent protocol but not following the 3 agent protocol. Muscarinic linkages to muscle nociceptor TRPA1 were also potentiated in the 4 agent but not the 3 agent, PB excluded, protocol. Although K v 7 activity changes diverged from the behavioral data, a K v 7 opener, retigabine, transiently reversed ambulation deficits. We concluded that PB played a critical role in the development of pain-like signs in a GWI rat model and that shifts in Na v 1.9 and TRPA1 activity were critical to the expression of these pain behaviors. Copyright © 2018 Elsevier Inc. All rights reserved.

Early-life lead exposure results in dose- and sex-specific effects on weight and epigenetic gene regulation in weanling mice

PubMed Central

Faulk, Christopher; Barks, Amanda; Liu, Kevin; Goodrich, Jaclyn M; Dolinoy, Dana C

2013-01-01

Aims Epidemiological and animal data suggest that the development of adult chronic conditions is influenced by early-life exposure-induced changes to the epigenome. This study investigates the effects of perinatal lead (Pb) exposure on DNA methylation and bodyweight in weanling mice. Materials & methods Viable yellow agouti (Avy) mouse dams were exposed to 0, 2.1, 16 and 32 ppm Pb acetate before conception through weaning. Epigenetic effects were evaluated by scoring coat color of Avy/a offspring and quantitative bisulfite sequencing of two retrotransposon-driven (Avy and CDK5 activator-binding protein intracisternal A particle element) and two imprinted (Igf2 and Igf2r) loci in tail DNA. Results Maternal blood Pb levels were below the limit of detection in controls, and 4.1, 25.1 and 32.1 μg/dl for each dose, respectively. Pb exposure was associated with a trend of increased wean bodyweight in males (p = 0.03) and altered coat color in Avy/a offspring. DNA methylation at Avy and the CDK5 activator-binding protein intracisternal A-particle element was significantly different from controls following a cubic trend (p = 0.04; p = 0.01), with male-specific effects at the Avy locus. Imprinted genes did not shift in methylation across exposures. Conclusion Dose- and sex-specific responses in bodyweight and DNA methylation indicate that Pb acts on the epigenome in a locus-specific fashion, dependent on the genomic feature hosting the CpG site of interest, and that sex is a factor in epigenetic response. PMID:24059796

A Pharmacokinetic Study of the Effects of Stress and Exercise on Chemical Exposure

DTIC Science & Technology

2001-03-20

Organophosphates such as diazinon and malathion are considered cholinesterase inhibitors, while carbamates such as physostigmine and pyridostigmine...bromide (PB) are considered reversible cholinesterase inhibitors. The possible Gulf War exposures to organophosphates such as diazinon and malathion...indicate that the physiological and protective effects of carbamates such as PB may depend on a narrow range of cholinesterase inhibition. Blood

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

PubMed Central

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

2018-01-01

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

DEVELOPMENTAL NEUROTOXICITY FOLLOWING NEONATAL EXPOSURE TO 3,3'-IMINODIPROPIONITRILE IN THE RAT

EPA Science Inventory

Adult exposure to the neurotoxicant 3,3'-iminodipropionitrile (IDPN) induces a hyperkinetic syndrome consisting of spontaneous head movements, abnormal circling, backwards locomotion, and sensory disruption. e report here the behavioral effects of developmental exposure to IDPN i...

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

Garden soil and house dust as exposure media for lead uptake in the mining village of Stratoni, Greece.

PubMed

Argyraki, Ariadne

2014-08-01

The relationships between two exposure media, garden soil and house dust, were studied for Pb uptake in Stratoni village in northern Greece, an industrial area of mining and processing of sulphide ore. Lead data for the two media were assessed in terms of total and bioaccessible content, measurement and geochemical variability, and mineralogical composition. It was found that total Pb was enriched in house dust samples by a factor of 2 on average. Total Pb concentration in soil samples had a maximum of 2,040 mg/kg and reached a maximum of 7,000 mg/kg in house dust samples. The estimated variability due to measurement uncertainty was dominated by the sampling process, and the proportion of sampling variance was greater for soil samples, indicating a higher degree of Pb heterogeneity in soil on the given spatial scale of sampling strata. Although the same general spatial trend was observed for both sampling media with decreasing Pb concentration by increasing distance from the ore-processing plant, Pb in dust samples displayed the highest concentrations within a 300-600-m zone from the ore-processing facility. The significant differences which were observed in Pb speciation between the studied media were explained by differences in mineralogical composition of outdoor soil and indoor dust. Lead-enriched Fe and Mn oxides predominated in soil samples while fine galena grains (<10-20 μm diameter) were the major Pb-bearing phase in dust samples. The integrated exposure uptake biokinetic model was used to predict the risk of elevated blood lead levels in children of Stratoni. Model prediction indicated an average probability of 61 % for blood-Pb to exceed 10 μg/dl. The results underline the importance of house dust in risk assessment and highlight the effect of outdoor and indoor conditions on the fate of Pb in the particular environment of Stratoni.

Effects of titanium dioxide nanoparticles on lead bioconcentration and toxicity on thyroid endocrine system and neuronal development in zebrafish larvae.

PubMed

Miao, Wei; Zhu, Biran; Xiao, Xiaohong; Li, Ying; Dirbaba, Niguse Bekele; Zhou, Bingsheng; Wu, Hongjuan

2015-04-01

Nanoparticles (NPs) have attracted considerable attention because of their wide range of applications. Interactions between heavy metals (e.g., Pb) and NPs in aquatic environments may modify the bioavailability and toxicity of heavy metals. Therefore, this study investigated the influence of NPs (e.g., nano-TiO2) on the bioavailability and toxicity of Pb and its effects in the thyroid endocrine and nervous systems of zebrafish (Danio rerio) larvae. Zebrafish embryos (2-h post-fertilization) were exposed to five concentrations of Pb alone (0, 5, 10, 20, and 30μg/L) or in combination with nano-TiO2 (0.1mg/L) until 6 days post-fertilization. Results showed that the bioconcentration of Pb was significantly enhanced when combined with nano-TiO2 than when used alone. Zebrafish exposure to Pb alone at 30μg/L significantly decreased the thyroid hormone levels (T4 and T3), whereas nano-TiO2 treatment alone did not produce detectable changes. The levels of T4 and T3 were further decreased when Pb was combined with nano-TiO2 than when used alone. The transcription of the thyroid hormone-related factor tg gene was remarkably down-regulated by Pb treatment alone but up-regulated when Pb was combined with nano-TiO2. The significant up-regulation of tshβ gene and the down-regulation of TTR gene expression in the hypothalamic-pituitary-thyroid were observed in Pb with or without nano-TiO2 treatment groups. In addition, the transcription of genes involved in central nervous system (CNS) development (α-tubulin, mbp, gfap and shha) were significantly down-regulated by Pb and nano-TiO2 co-exposure as compared with Pb exposure alone. The locomotion activity analyzes confirmed that nano-TiO2 might enhance the toxicity of Pb to CNS development. These results suggest that nano-TiO2 increase bioconcentration of lead, which lead to the disruption of thyroid endocrine and neuronal system in zebrafish larvae. Copyright © 2015 Elsevier B.V. All rights reserved.

Helping Children Cope with the Consequences of Violence.

ERIC Educational Resources Information Center

Wallach, Lorraine B.

The first part of this paper on the developmental consequences of children's exposure to chronic violence provides background information on the problem of violence. Developmental consequences of exposure to domestic and community violence for children at various developmental levels are briefly outlined. Consequences for children include: (1)…

USING THE MEDAKA EMBRYO ASSAY TO INVESTIGATE DEVELOPMENTAL ETHANOL TOXICITY.

EPA Science Inventory

Ethanol (EtOH) is a well-known developmental toxicant that produces a range of abnormal phenotypes. While the toxic potential of developmental EtOH exposure is well characterized, the effect of the timing of exposure on the extent of toxicity remains unknown. Fish models such as ...

Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District.

PubMed

Beyer, W Nelson; Franson, J Christian; French, John B; May, Thomas; Rattner, Barnett A; Shearn-Bochsler, Valerie I; Warner, Sarah E; Weber, John; Mosby, David

2013-10-01

Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000-3,200 mg Pb/kg. Analyses of earthworms [33-4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11-3.0 (reference) and 1.3-30 (contaminated) and American robin (Turdus migratorius) = 0.43-8.5 (reference) and 7.6-72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32%) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9%) with systemic toxic effects, and 4 (12%) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58-82% in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District

USGS Publications Warehouse

Beyer, W. Nelson; Franson, J. Christian; French, John B.; May, Thomas; Rattner, Barnett A.; Shearn-Bochsler, Valerie I.; Warner, Sarah E.; Weber, John; Mosby, David

2013-01-01

Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

A Chronic Longitudinal Characterization of Neurobehavioral and Neuropathological Cognitive Impairment in a Mouse Model of Gulf War Agent Exposure

PubMed Central

Zakirova, Zuchra; Crynen, Gogce; Hassan, Samira; Abdullah, Laila; Horne, Lauren; Mathura, Venkatarajan; Crawford, Fiona; Ait-Ghezala, Ghania

2016-01-01

Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component that includes memory impairment as well as neurological and musculoskeletal deficits. Previous studies have shown that in the First Persian Gulf War conflict (1990–1991) exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and permethrin (PER), were key contributors to the etiology of GWI. For this study, we used our previously established mouse model of GW agent exposure (10 days PB+PER) and undertook an extensive lifelong neurobehavioral characterization of the mice from 11 days to 22.5 months post exposure in order to address the persistence and chronicity of effects suffered by the current GWI patient population, 24 years post-exposure. Mice were evaluated using a battery of neurobehavioral testing paradigms, including Open Field Test (OFT), Elevated Plus Maze (EPM), Three Chamber Testing, Radial Arm Water Maze (RAWM), and Barnes Maze (BM) Test. We also carried out neuropathological analyses at 22.5 months post exposure to GW agents after the final behavioral testing. Our results demonstrate that PB+PER exposed mice exhibit neurobehavioral deficits beginning at the 13 months post exposure time point and continuing trends through the 22.5 month post exposure time point. Furthermore, neuropathological changes, including an increase in GFAP staining in the cerebral cortices of exposed mice, were noted 22.5 months post exposure. Thus, the persistent neuroinflammation evident in our model presents a platform with which to identify novel biological pathways, correlating with emergent outcomes that may be amenable to therapeutic targeting. Furthermore, in this work we confirmed our previous findings that GW agent exposure causes neuropathological changes, and have presented novel data which demonstrate increased disinhibition, and lack of social preference in PB+PER exposed mice at 13 months after exposure. We also extended upon our previous work to cover the lifespan of the laboratory mouse using a battery of neurobehavioral techniques. PMID:26793076

High-Precision (MC-ICPMS) Isotope Ratio Analysis Reveals Contrasting Sources of Elevated Blood Lead Levels of an Adult with Retained Bullet Fragments, and of His Child, in Milwaukee, Wisconsin.

PubMed

Smith, Kate E; Shafer, Martin M; Weiss, Debora; Anderson, Henry A; Gorski, Patrick R

2017-05-01

Exposure to the neurotoxic element lead (Pb) continues to be a major human health concern, particularly for children in US urban settings, and the need for robust tools for assessment of exposure sources has never been greater. The latest generation of multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) instrumentation offers the capability of using Pb isotopic signatures as a tool for environmental source tracking in public health. We present a case where MC-ICPMS was applied to isotopically resolve Pb sources in human clinical samples. An adult male and his child residing in Milwaukee, Wisconsin, presented to care in August 2015 with elevated blood lead levels (BLLs) (>200 μg/dL for the adult and 10 μg/dL for the child). The adult subject is a gunshot victim who had multiple bullet fragments embedded in soft tissue of his thigh for approximately 10 years. This study compared the high-precision isotopic fingerprints (<1 ‰ 2σ external precision) of Pb in the adult's and child's whole blood (WB) to the following possible Pb sources: a surgically extracted bullet fragment, household paint samples and tap water, and a Pb water-distribution pipe removed from servicing a house in the same neighborhood. Pb in the bullet and adult WB were nearly isotopically indistinguishable (matching within 0.05-0.56 ‰), indicating that bullet fragments embedded in soft tissue could be the cause of both acute and chronic elevated blood Pb levels. Among other sources investigated, no single source dominated the child's exposure profile as reflected in the elevated BLL.

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases

PubMed Central

Xu, Joella; Huang, Guannan; Guo, Tai L.

2016-01-01

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases. PMID:29051427

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases.

PubMed

Xu, Joella; Huang, Guannan; Guo, Tai L

2016-09-26

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases.

Longitudinal investigation of exposure to arsenic, cadmium, and lead in drinking water.

PubMed

Ryan, P B; Huet, N; MacIntosh, D L

2000-08-01

Arsenic, cadmium, and lead have been associated with various forms of cancer, nephrotoxicity, central nervous system effects, and cardiovascular disease in humans. Drinking water is a well-recognized pathway of exposure to these metals. To improve understanding of the temporal dimension of exposure to As, Cd, and Pb in drinking water, we obtained 381 samples of tap and/or tap/filtered water and self-reported rates of drinking water consumption from 73 members of a stratified random sample in Maryland. Data were collected at approximately 2-month intervals from September 1995 through September 1996. Concentrations of As (range < 0.2-13.8 microg/L) and Pb (< 0.1-13.4 microg/L) were within the ranges reported for the United States, as were the rates of drinking water consumption (median < 0.1-4.1 L/day). Cd was present at a detectable level in only 8.1% of the water samples. Mean log-transformed concentrations and exposures for As and Pb varied significantly among sampling cycles and among respondents, as did rates of drinking water consumption, according to a generalized linear model that accounted for potential correlation among repeated measures from the same respondent. We used the intraclass correlation coefficient of reliability to attribute the total variance observed for each exposure metric to between-person and within-person variability. Between-person variability was estimated to account for 67, 81, and 55% of the total variance in drinking water consumption, As exposure (micrograms per day), and Pb exposure (micrograms per day), respectively. We discuss these results with respect to their implications for future exposure assessment research, quantitative risk assessment, and environmental epidemiology.

Exposure assessment of organochlorine pesticides, arsenic, and lead in children from the major agricultural areas in Sonora, Mexico.

PubMed

Meza-Montenegro, Maria M; Valenzuela-Quintanar, Ana I; Balderas-Cortés, José J; Yañez-Estrada, Leticia; Gutiérrez-Coronado, Maria L; Cuevas-Robles, Alberto; Gandolfi, A Jay

2013-04-01

There is a lack of information of exposure to organochlorine pesticides (OCP) and some metals, such as lead (Pb) and arsenic (As), both of which were used as arsenicals pesticides, in children living in the major agricultural areas of Mexico. The objective of this study was to assess the exposure of children to different OCP, As, and Pb in the Yaqui and Mayo valleys of Sonora to generate population baseline levels of these toxins. A cross-sectional study was undertaken in 165 children (age 6-12 years old) from 10 communities from both valleys during 2009. Blood samples were analyzed for OCP and Pb and first morning void urine for inorganic As (InAs). All of the blood samples had detectable levels of dichlorodiphenyltrichloroethylene (p,p'-DDE) ranging from 0.25 to 10.3 μg/L. However lindane, dichlorodiphenyltrichloroethane (p,p'-DDT), aldrin, and endosulfan were detected in far less of the population (36.4, 23.6, 9.1, and 3 %, respectively). Methoxychlor and endrin were not found in any sample. The average value of Pb in this population was 3.2 μg Pb/dL (range 0.17-9.0) with 8.5 % of the samples having levels <5.0 μg Pb/dL. Urinary As levels ranged from 5.4 to 199 μg As/L with an average value of 31.0 μg As/L. Levels > 50 μg/L were observed in 12.7 % of the samples. Our results show that is important to start a risk-reduction program to decrease exposure to these toxins in Mexican communities. In addition, the results can be used to establish the baseline levels of exposure to these toxins in this agricultural region and may be used as a reference point for regulatory agencies.

Exposure Assessment of Organochlorine Pesticides, Arsenic, and Lead in Children From the Major Agricultural Areas in Sonora, Mexico

PubMed Central

Valenzuela-Quintanar, Ana I.; Balderas-Cortés, José J.; Yañez-Estrada, Leticia; Gutiérrez-Coronado, Maria L.; Cuevas-Robles, Alberto; Gandolfi, A. Jay

2014-01-01

There is a lack of information of exposure to organochlorine pesticides (OCP) and some metals, such as lead (Pb) and arsenic (As), both of which were used as arsenicals pesticides, in children living in the major agricultural areas of Mexico. The objective of this study was to assess the exposure of children to different OCP, As, and Pb in the Yaqui and Mayo valleys of Sonora to generate population baseline levels of these toxins. A cross-sectional study was undertaken in 165 children (age 6–12 years old) from 10 communities from both valleys during 2009. Blood samples were analyzed for OCP and Pb and first morning void urine for inorganic As (InAs). All of the blood samples had detectable levels of dichlorodiphenyltrichloroethylene (p,p′-DDE) ranging from 0.25 to 10.3 μg/L. However lindane, dichlorodiphenyltrichloroethane (p,p′-DDT), aldrin, and endosulfan were detected in far less of the population (36.4, 23.6, 9.1, and 3 %, respectively). Methoxychlor and endrin were not found in any sample. The average value of Pb in this population was 3.2 μg Pb/dL (range 0.17–9.0) with 8.5 % of the samples having levels <5.0 μg Pb/dL. Urinary As levels ranged from 5.4 to 199 μg As/L with an average value of 31.0 μg As/L. Levels > 50 μg/L were observed in 12.7 % of the samples. Our results show that is important to start a risk-reduction program to decrease exposure to these toxins in Mexican communities. In addition, the results can be used to establish the baseline levels of exposure to these toxins in this agricultural region and may be used as a reference point for regulatory agencies. PMID:23254566

Does background postnatal methyl mercury exposure in toddlers affect cognition and behavior?

PubMed

Cao, Yang; Chen, Aimin; Jones, Robert L; Radcliffe, Jerilynn; Caldwell, Kathleen L; Dietrich, Kim N; Rogan, Walter J

2010-01-01

Because the toxicological effects of mercury (Hg) are more serious in the developing central nervous system of children than adults, there are growing concerns about prenatal and early childhood Hg exposure. This study examined postnatal methylmercury (MeHg) exposure and cognition and behavior in 780 children enrolled in the Treatment of Lead (Pb)-exposed Children clinical trial (TLC) with 396 children allocated to the succimer and 384 to the placebo groups. Mercury exposure was determined from analyses of blood drawn 1 week before randomization and 1 week after treatment began when succimer had its maximal effect on blood Pb (PbB). The baseline MeHg concentrations were 0.54 microg/L and 0.52 microg/L and post-treatment concentrations were 0.51 microg/L and 0.48 microg/L for placebo and succimer groups, respectively. Because the baseline characteristics in the two groups were balanced and because succimer had little effect on MeHg concentration and no effect on the cognitive or behavioral test scores, the groups were combined in the analysis of MeHg and neurodevelopment. The children's IQ and neurobehavioral performance were tested at age 2, 5 and 7 years. We saw weak, non-significant but consistently positive associations between blood MeHg and IQ test scores in stratified, spline regression and generalized linear model data analyses. The behavioral problem scores were constant or decreased slightly with increasing MeHg concentration. Additional adjustment for PbB levels in multivariable models did not alter the conclusion for MeHg and IQ scores, but did confirm that concurrent PbB was strongly associated with IQ and behavior in TLC children. The effects of MeHg on neurodevelopmental indices did not substantially differ by PbB strata. We conclude that at the present background postnatal MeHg exposure levels of US children, adverse effects on children's IQ and behavior are not detectable. 2009 Elsevier Inc. All rights reserved.

Developmental variations in the impact of intimate partner violence exposure during childhood

PubMed Central

Howell, Kathryn H.; Barnes, Sarah E.; Miller, Laura E.; Graham-Bermann, Sandra A.

2016-01-01

Abstract: Background: Intimate partner violence (IPV) is a pervasive problem impacting individuals around the globe. The consequences of IPV extend beyond the adults in the relationship, as children witness a significant proportion of such violence. Exposure to IPV during childhood has devastating effects across multiple domains of functioning. Methods: This article reviews empirical studies of the effects of exposure to IPV by developmental stage. Results: The psychological, social, physical, and cognitive consequences of witnessing IPV are examined across development; from the impact of prenatal exposure to effects in infancy and toddlerhood, the preschool years, school-aged children, and adolescence. Conclusions: The review concludes by providing suggestions for future research based on the identified developmental variations, recommendations for developmentally-sensitive interventions for children who have witnessed IPV, and directions for policy to address the issue of violence exposure early in the lives of children. PMID:26804945

Developmental Toxicology##

EPA Science Inventory

Developmental toxicology encompasses the study of developmental exposures, pharmacokinetics, mechanisms, pathogenesis, and outcomes potentially leading to adverse health effects. Manifestations of developmental toxicity include structural malformations, growth retardation, functi...

An analysis of human exposure to trace elements from deliberate soil ingestion and associated health risks.

PubMed

Ngole-Jeme, Veronica M; Ekosse, Georges-Ive E; Songca, Sandile P

2018-01-01

Fifty-seven samples of soils commonly ingested in South Africa, Swaziland, Democratic Republic of Congo (DRC), and Togo were analyzed for the concentrations of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) and their bioaccessibility in the human gastrointestinal tract. Bioaccessibility values were used to calculate daily intake, and hazard quotient of each trace element, and chronic hazard index (CHI) of each sample. Carcinogenic risk associated with As and Ni exposure were also calculated. Mean pseudo-total concentrations of trace elements in all samples were 7.2, 83.3, 77.1, 15.4, 28.6, 24.9, 56.1, 2.8, and 26.5 mg/kg for As, Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb, respectively. Percent bioaccessibility of Pb (13-49%) and Zn (38-56%) were highest among trace elements studied. Average daily intake values were lower than their respective reference doses for ell elements except for Pb in selected samples. Samples from DRC presented the highest health risks associated with trace element exposure with most of the samples having CHI values between 0.5 and 1.0. Some samples had higher than unacceptable values of carcinogenic risk associated with As and Ni exposure. Results indicate low trace element exposure risk from ingesting most of the soil samples.

Deer exposed to exceptionally high concentrations of lead near the continental mine in Idaho, USA

USGS Publications Warehouse

Beyer, W.N.; Gaston, G.; Brazzle, R.; O'Connell, A.F.; Audet, D.J.

2007-01-01

Habitat surrounding the inactive Continental Mine in northern Idaho, USA, supports bear (Ursus arctos, Ursus americanus), moose (Alces alces), elk (Cervus elaphus), woodland caribou (Rangifer tarandus caribou), and abundant mule (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus). Tailings on the mining site were capped and remediated in 2003 to reduce environmental exposure of surrounding soil and sediments of Blue Joe Creek, downslope of the mine. Before capping, the mean Pb concentration in deer pellets collected on-site was 920 mg/kg of Pb (dry wt). This exposure, if chronic, would be comparable to an exposure that could be lethal to cattle or horses. Surprisingly, the mean pellet Pb concentration of 950 mg/kg in 2004 was as high as it was before remediation, and it was related to a high rate of soil ingestion. Mean soil content of the pellets collected from the capped site in 2004 was 22% dry weight, estimated from the acid-insoluble ash, a marker of soil ingestion. Clumps of sand and bits of rock were observed inside some of the pellets, and Pb concentrations in the pellets were correlated (p < 0.05) with soil content. Although terrestrial risk assessments generally estimate exposure from diets and from incidentally ingested soil, the deer at this site were directly ingesting contaminated soil or mining waste. The mean Pb concentration of this ingested soil was estimated as 6,700 mg/kg and the maximum as 25,000 mg/kg, well above the Pb concentrations measured in the remediated cap. The deer seemed to be ingesting soil or mining waste from one or more small but highly contaminated sources located beyond the remediated cap.

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.

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.

Effects of low-level organic selenium on lead-induced alterations in neural cell adhesion molecules.

PubMed

Wang, Mao; Fu, Hongjun; Xiao, Yongmei; Ai, Baomin; Wei, Qing; Wang, Shuyu; Liu, Tao; Ye, Liuqing; Hu, Qiansheng

2013-09-12

Low-level lead (Pb) exposure has been reported to impair the formation and consolidation of learning and memory by inhibiting the expression of neural cell adhesion molecules (NCAMs) and altering the temporal profile of its polysialylation state. In this study, we investigated whether administration of low-level organic selenium (selenomethionine, Se) at different time points could affect Pb-induced changes of NCAMs in female Wistar rats. Here we reported that the exposure of Se (60μg/kg body weight/day) at different time points significantly alleviated Pb-induced reductions in the mRNA and protein levels of NCAMs, and increases in the mRNA levels of two polysialyltransferases (St8sia II, Stx; St8sia IV, Pst) as well as the sialyltransferase activity (p<0.05). The concentrations of Pb in blood and hippocampi of Wistar rats treated with the combination of Se and Pb were significantly lower than those treated with Pb alone (p<0.05). Our results suggest that low-level organic Se can not only prevent but also reverse Pb-induced alterations in the expression and polysialylated state of NCAMs as well as the concentration of Pb in rat blood and hippocampus. © 2013 Elsevier B.V. All rights reserved.

XRF-measured bone lead (Pb) as a biomarker for Pb exposure and toxicity among children diagnosed with Pb poisoning.

PubMed

Specht, Aaron J; Lin, Yanfen; Weisskopf, Marc; Yan, Chonghuai; Hu, Howard; Xu, Jian; Nie, Linda H

2016-01-01

Childhood lead (Pb) poisoning remains a global issue, especially in industrial areas. In this study, 115 children with average age 5.7 years were recruited as either patient diagnosed with Pb poisoning or controls at Xinhua Hospital in China. The subjects' bone Pb was measured with a K-shell X-ray fluorescence (KXRF) and a portable X-ray fluorescence (XRF) system. A significant correlation between KXRF bone Pb and blood Pb and portable XRF and KXRF measurements were observed. The half-life of blood-lead was calculated to be 9.96 ± 3.92 d. Our results indicate that bone is a useful biomarker for Pb in children.

Effect of dissolved humic acid on the Pb bioavailability in soil solution and its consequence on ecological risk.

PubMed

An, Jinsung; Jho, Eun Hea; Nam, Kyoungphile

2015-04-09

Current risk characterization in ecological risk assessment does not consider bioavailability of heavy metals, which highly depends on physicochemical properties of environmental media. This study was set to investigate the effect of humic acid (HA), used as a surrogate of organic matter, on Pb toxicity and the subsequent effect on risk characterization in ecological risk assessment. Pb toxicity was assessed using Microtox(®) in the presence and absence of two different forms of HA, particulate HA (pHA) and dissolved HA (dHA). With increasing contact time, the EC10 values increased (i.e., the toxic effects decreased) and the dissolved Pb concentrations of the filtrates decreased. The high correlation (R = 0.88, p < 0.001) between toxic effects determined using both the mixture and its filtrate as exposure media leads us to conclude that the Pb toxicity highly depends on the soluble fraction. Also, reduced Pb toxicity with increasing dHA concentrations, probably due to formation of Pb-dHA complexes, indicated that Pb toxicity largely comes from free Pb ions. Overall, this study shows the effect of HA on metal toxicity alleviation, and emphasizes the need for incorporating the bioavailable heavy metal concentrations in environmental media as a point of exposure in ecological risk assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of dietary selenium of organic form against lead toxicity on the antioxidant system in Cyprinus carpio.

PubMed

Özkan-Yilmaz, Ferbal; Özlüer-Hunt, Arzu; Gündüz, Suna Gül; Berköz, Mehmet; Yalin, Serap

2014-04-01

In this study was evaluated potential protective effect of organic selenium (Se) on heavy metal stress induced by lead (Pb) in Cyprinus carpio. For this reason, C. carpio was exposed to sublethal concentration of Pb (1.5 mg/L Pb(NO3)2) for 14 days. The fish were fed a basal (control; measured 0.55 mg/kg Se) diet or a basal diet supplemented with 2.50 mg/kg (measured 2.92 mg/kg Se) organic Se (Sel-Plex(®)) during the experiment period. The variations in glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) activities, and levels of reduced glutathione (GSH) with malondialdehyde (MDA) in liver and brain tissues of C. carpio were investigated in experimental groups. GSH levels in liver and brain tissues were significantly decreased by exposure to Pb. GST activity was significantly increased (p < 0.05) in liver tissue, but decreased in brain of treated fish by exposure to Pb. Also, GSH-Px activity was significantly increased in liver tissue, but decreased in brain of Pb-treated fish. Levels of MDA were increased in liver and brain of Pb-treated fish. The organic Se treatment for Pb-intoxicated animals improved activities of GSH-Px, GST and levels of MDA within normal limits. Supplemented Se could be able to improve Pb-induced oxidative stress by decreasing lipid peroxidation and regulating antioxidant defense system in tissues.

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.

Fractional bio-accessibility: A new tool for Pb risk assessment from urban garden soils and superfund sites

USDA-ARS?s Scientific Manuscript database

Pb contamination of urban soils and its strong association with elevated blood Pb concentrations, especially in children, has raised concerns about whether gardens should be recommended for urban areas. Reliable evaluation of the potential hazard to the public from exposure to urban garden soils gr...

Dynamic biological exposure indexes for n-hexane and 2,5-hexanedione, suggested by a physiologically based pharmacokinetic model

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

Perbellini, L.; Mozzo, P.; Olivato, D.

Biological exposure index (BEI) of n-hexane was studied for accuracy using a physiologically based pharmacokinetic (PB-PK) model. The kinetics of n-hexane in alveolar air, blood, urine, and other tissues were simulated for different values of alveolar ventilations and also for constant and variable exposures. The kinetics of 2,5-hexanedione, the toxic n-hexane metabolite, were also simulated. The ranges of n-hexane concentrations in biological media and the urinary concentrations of 2,5-hexanedione are discussed in connection with a mean n-hexane exposure of 180 mg/m3 (50 ppm) (threshold limit value (TLV) suggested by American Conference of Governmental Industrial Hygienists (ACGIH) for 1988-89). The experimentalmore » and field data as well as those predicted by simulation with the PB-PK model were comparable. The physiological-pharmacokinetic simulations are used to propose the dynamic BEIs of n-hexane and 2,5-hexanedione. The use of simulation with PB-PK models enables a better understanding of the limits, advantages, and issues associated with biological monitoring of exposures to industrial solvents.« less

Gene expression profiles in the cerebellum and hippocampus following exposure to a neurotoxicant, Aroclor 1254: Developmental effects.

EPA Science Inventory

The developmental consequences of exposure to the polychlorinated biphenyls (PCBs) have been widely studied, making PCBs a unique model to understand issues related to environmental mixture of persistent chemicals. PCB exposure in humans adversely affects neurocognitive developm...

ONTOGENETIC ALTERATIONS IN MOLECULAR AND STRUCTURAL CORRELATES OF DENDRITIC GROWTH FOLLOWING DEVELOPMENTAL EXPOSURE TO POLYCHLORINATED BIPHENYLS.

EPA Science Inventory

This is the first report showing both molecular and structural changes in brain following developmental exposure to a neurotoxicant. It is known that perinatal exposure to a neurotoxicant, polychlorinated biphenyls (PCBs), is associated with decreased IQ scores, impaired learnin...

Redeployment of germ layers related TFs shows regionalized expression during two non-embryonic developments.

PubMed

Ricci, Lorenzo; Cabrera, Fabien; Lotito, Sonia; Tiozzo, Stefano

2016-08-01

In all non-vertebrate metazoan phyla, species that evolved non-embryonic developmental pathways as means of propagation or regeneration can be found. In this context, new bodies arise through asexual reproduction processes (such as budding) or whole body regeneration, that lack the familiar temporal and spatial cues classically associated with embryogenesis, like maternal determinants, or gastrulation. The molecular mechanisms underlying those non-embryonic developments (i.e., regeneration and asexual reproduction), and their relationship to those deployed during embryogenesis are poorly understood. We have addressed this question in the colonial ascidian Botryllus schlosseri, which undergoes an asexual reproductive process via palleal budding (PB), as well as a whole body regeneration by vascular budding (VB). We identified early regenerative structures during VB and then followed the fate of differentiating tissues during both non-embryonic developments (PB and VB) by monitoring the expression of genes known to play key functions in germ layer specification with well conserved expression patterns in solitary ascidian embryogenesis. The expression patterns of FoxA1, GATAa, GATAb, Otx, Bra, Gsc and Tbx2/3 were analysed during both PB and VB. We found that the majority of these transcription factors were expressed during both non-embryonic developmental processes, revealing a regionalization of the palleal and vascular buds. Knockdown of GATAa by siRNA in palleal buds confirmed that preventing the correct development of one of these regions blocks further tissue specification. Our results indicate that during both normal and injury-induced budding, a similar alternative developmental program operates via early commitment of epithelial regions. Copyright © 2016. Published by Elsevier Inc.

A Drosophila model for fetal alcohol syndrome disorders: role for the insulin pathway

PubMed Central

McClure, Kimberly D.; French, Rachael L.; Heberlein, Ulrike

2011-01-01

SUMMARY Prenatal exposure to ethanol in humans results in a wide range of developmental abnormalities, including growth deficiency, developmental delay, reduced brain size, permanent neurobehavioral abnormalities and fetal death. Here we describe the use of Drosophila melanogaster as a model for exploring the effects of ethanol exposure on development and behavior. We show that developmental ethanol exposure causes reduced viability, developmental delay and reduced adult body size. We find that flies reared on ethanol-containing food have smaller brains and imaginal discs, which is due to reduced cell division rather than increased apoptosis. Additionally, we show that, as in mammals, flies reared on ethanol have altered responses to ethanol vapor exposure as adults, including increased locomotor activation, resistance to the sedating effects of the drug and reduced tolerance development upon repeated ethanol exposure. We have found that the developmental and behavioral defects are largely due to the effects of ethanol on insulin signaling; specifically, a reduction in Drosophila insulin-like peptide (Dilp) and insulin receptor expression. Transgenic expression of Dilp proteins in the larval brain suppressed both the developmental and behavioral abnormalities displayed by ethanol-reared adult flies. Our results thus establish Drosophila as a useful model system to uncover the complex etiology of fetal alcohol syndrome. PMID:21303840

DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

PubMed Central

Yedjou, Clement G.; Tchounwou, Hervey M.; Tchounwou, Paul B.

2015-01-01

In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO3)2] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO3)2 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI) assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05) increase of necrotic cell death in Pb(NO3)2-treated cells, indicative of membrane rupture by Pb(NO3)2 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05) in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO3)2 exposure significantly (p < 0.05) increased the proportion of caspase-3 positive cells (apoptotic cells) compared to the control. The flow cytometry assessment also indicated Pb(NO3)2 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO3)2 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO3)2 exposure and its associated adverse health effects. PMID:26703663

DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells.

PubMed

Yedjou, Clement G; Tchounwou, Hervey M; Tchounwou, Paul B

2015-12-22

In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO₃)₂] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO₃)₂ for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI) assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05) increase of necrotic cell death in Pb(NO₃)₂-treated cells, indicative of membrane rupture by Pb(NO₃)₂ compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05) in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO₃)₂ exposure significantly (p < 0.05) increased the proportion of caspase-3 positive cells (apoptotic cells) compared to the control. The flow cytometry assessment also indicated Pb(NO₃)₂ exposure caused cell cycle arrest at the G₀/G₁ checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO₃)₂ inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G₀/G₁ checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO₃)₂ exposure and its associated adverse health effects.

The Level of Selenium and Oxidative Stress in Workers Chronically Exposed to Lead.

PubMed

Pawlas, Natalia; Dobrakowski, Michał; Kasperczyk, Aleksandra; Kozłowska, Agnieszka; Mikołajczyk, Agnieszka; Kasperczyk, Sławomir

2016-03-01

The possible beneficial role of selenium (Se) on the oxidative stress induced by lead (Pb) is still unclear in humans. Therefore, the aim of the present study was to explore the associations among the Se levels, chronic Pb exposure, oxidative stress parameters, and parameters characterizing the function of the antioxidant defense system in men who are occupationally exposed to Pb. Based on the median serum Se concentrations, the 324 study subjects were divided into two subgroups: a subgroup with a low Se level (L-Se) and a subgroup with a high Se level (H-Se). The levels of lead (PbB) and zinc protoporphyrin (ZPP) in the blood and the delta-aminolevulinic acid (ALA) level in the urine served as indices of Pb exposure. The PbB level was significantly lower in the H-Se group compared to that in the L-Se group by 6 %. The levels of 8-hydroxyguanosine and lipofuscin (LPS) and the activity of superoxide dismutase were significantly lower in the H-Se group compared to that in the L-Se group by 17, 19, and 11 %, respectively. However, the glutathione level (GSH) and the activities of glutathione peroxidase (GPx) and catalase were significantly higher by 9, 23, and 3 %. Spearman correlations showed positive associations between the Se level and GPx activity and GSH level. A lower serum Se level in chronically Pb-exposed subjects is associated with higher Pb blood levels and an elevated erythrocyte LPS level, which reflects the intensity of oxidative stress. Besides, in a group of Pb-exposed subjects with lower serum Se level, depleted GSH pool and decreased activity of GPx in erythrocytes were reported. However, the present results are inadequate to recommend Se supplementation for chronic lead exposure at higher doses than would be included in a normal diet except for selenium deficiency.

Effects on the hepatic transcriptome of chicken embryos in ovo exposed to phenobarbital.

PubMed

Guo, Jiahua; Ito, Shohei; Nguyen, Hoa Thanh; Yamamoto, Kimika; Iwata, Hisato

2018-05-21

This work aimed at evaluating the toxic effects of in ovo exposure to phenobarbital (PB) and unveiling the mode of action by transcriptome analysis in the embryonic liver of a model avian species, chicken (Gallus gallus). Embryos were initially treated with saline or 1 μg PB /g egg at Hamburger Hamilton Stage (HHS) 1 (1st day), followed by 20 days of incubation to HHS 46. At 21st day, chicks that pipped successfully were euthanized and dissected for assessing the PB caused effects on phenotypes and the liver transcriptome in both genders. In the PB treatment group, a 7% attenuation in tarsus length was found in females. While no adverse phenotypic effect on the liver somatic index (LSI) was observed, PB caused significant changes in the expressions of 52 genes in males and 516 genes in females (False Discovery Rate < 0.2, p value < 0.05, and absolute fold change > 2). PB exposure modulated the genes primarily enriched in the biological pathways of the cancer, cardiac development, immune response, lipid metabolism, and skeletal development in both genders, and altered expressions of genes related to the cellular process and neural development in females. However, mRNA expressions of chicken xenobiotic receptor (CXR)-mediated CYP genes were not induced in the PB treatment groups, regardless of males and females. On the contrary, PB exposure repressed the mRNA expressions of CYP2AC2 in males and CYP2R1, CYP3A37, and CYP8B1 in females. Although transcription factors (TFs) including SREBF1 and COUP-TFII were predicted to be commonly activated in both genders, some TFs were activated in a gender-dependent manner, such as PPARa in males and BRCA1 and IRF9 in females. Taken together, our results provided an insight into the mode of action of PB on the chicken embryos. Copyright © 2018 Elsevier Inc. All rights reserved.

Embryonic exposure to an aqueous coal dust extract results in gene expression alterations associated with the development and function of connective tissue and the hematological system, immunological and inflammatory disease, and cancer in zebrafish.

PubMed

Caballero-Gallardo, Karina; Wirbisky-Hershberger, Sara E; Olivero-Verbel, Jesus; de la Rosa, Jesus; Freeman, Jennifer L

2018-03-01

Coal mining is one of the economic activities with the greatest impact on environmental quality. At all stages contaminants are released as particulates such as coal dust. The first aim of this study was to obtain an aqueous coal dust extract and characterize its composition in terms of trace elements by ICP-MS. In addition, the developmental toxicity of the aqueous coal extract was evaluated using zebrafish (Danio rerio) after exposure to different concentrations (0-1000 ppm; μg mL -1 ) to establish acute toxicity, morphology and transcriptome changes. Trace elements within the aqueous coal dust extract present at the highest concentrations (>10 ppb) included Sr, Zn, Ba, As, Cu and Se. In addition, Cd and Pb were found in lower concentrations. No significant difference in mortality was observed (p > 0.05), but a delay in hatching was found at 0.1 and 1000 ppm (p < 0.05). No significant differences in morphological characteristics were observed in any of the treatment groups (p > 0.05). Transcriptomic results of zebrafish larvae revealed alterations in 77, 61 and 1376 genes in the 1, 10, and 100 ppm groups, respectively. Gene ontology analysis identified gene alterations associated with the development and function of connective tissue and the hematological system, as well as pathways associated with apoptosis, the cell cycle, transcription, and oxidative stress including the MAPK signaling pathway. In addition, altered genes were associated with cancer; connective tissue, muscular, and skeletal disorders; and immunological and inflammatory diseases. Overall, this is the first study to characterize gene expression alterations in response to developmental exposure to aqueous coal dust residue from coal mining with transcriptome results signifying functions and systems to target in future studies.

Noninvasive Biomonitoring Approaches to Determine Dosimetry and Risk Following Acute Chemical Exposure: Analysis of Lead or Organophosphate Insecticide in Saliva

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

Timchalk, Chuck; Poet, Torka S.; Kousba, Ahmed A.

2004-04-01

There is a need to develop approaches for assessing risk associated with acute exposures to a broad-range of chemical agents and to rapidly determine the potential implications to human health. Non-invasive biomonitoring approaches are being developed using reliable portable analytical systems to quantitate dosimetry utilizing readily obtainable body fluids, such as saliva. Saliva has been used to evaluate a broad range of biomarkers, drugs, and environmental contaminants including heavy metals and pesticides. To advance the application of non-invasive biomonitoring a microfluidic/ electrochemical device has also been developed for the analysis of lead (Pb), using square wave anodic stripping voltammetry. Themore » system demonstrates a linear response over a broad concentration range (1 2000 ppb) and is capable of quantitating saliva Pb in rats orally administered acute doses of Pb-acetate. Appropriate pharmacokinetic analyses have been used to quantitate systemic dosimetry based on determination of saliva Pb concentrations. In addition, saliva has recently been used to quantitate dosimetry following exposure to the organophosphate insecticide chlorpyrifos in a rodent model system by measuring the major metabolite, trichloropyridinol, and saliva cholinesterase inhibition following acute exposures. These results suggest that technology developed for non-invasive biomonitoring can provide a sensitive, and portable analytical tool capable of assessing exposure and risk in real-time. By coupling these non-invasive technologies with pharmacokinetic modeling it is feasible to rapidly quantitate acute exposure to a broad range of chemical agents. In summary, it is envisioned that once fully developed, these monitoring and modeling approaches will be useful for accessing acute exposure and health risk.« less

Influence of titanium dioxide nanoparticles on cadmium and lead bioaccumulations and toxicities to Daphnia magna

NASA Astrophysics Data System (ADS)

Li, Ling; Sillanpää, Markus; Schultz, Eija

2017-06-01

Titanium dioxide nanoparticles (TiO2 NPs) have attracted considerable concerns due to the increasing production and widespread applications, while their influences on other co-existing pollutants in real environment are not well studied. In this paper, the colloidal stability of TiO2 NPs in the exposure medium was first evaluated, and then, the medium was modified so that TiO2 NP suspension remained stable over the exposure period. Finally, using the optimized exposure medium, the effects of cadmium (Cd) and lead (Pb) on Daphnia magna both in the absence and presence of TiO2 NPs were investigated. Results showed that 2 mg L-1 of TiO2 NPs was well dispersed in 1:20 diluted Elendt M7 medium without EDTA, and no immobility was observed. The presence of the nanoparticles increased the bioaccumulation and toxicity of Cd to the daphnias. On the contrary, while Pb bioaccumulation was enhanced by three to four times, toxicity of Pb was reduced in the presence of TiO2 NPs. The decreased toxicity of Pb was more likely attributed to the decreased bioavailability of free Pb ion due to adsorption and speciation change of Pb in the presence of TiO2 NPs. Additionally, surface-attached TiO2 NPs combined with adsorbed heavy metals caused adverse effects on daphnia swimming and molting behavior, which is supposed to lead to chronic toxicity.

Blood lead concentrations in 1-3 year old Lebanese children: a cross-sectional study.

PubMed

Nuwayhid, Iman; Nabulsi, Mona; Muwakkit, Samar; Kouzi, Sarah; Salem, George; Mikati, Mohamed; Ariss, Majd

2003-04-15

Childhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb >or= 100 microg/L) among 1-3 year old children. It also examines the need for universal blood lead screening. This is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997-98. Blood was drawn on participating children for lead analysis and a structured questionnaire was introduced to mothers asking about social, demographic, and residence characteristics, as well as potential risk factors for lead exposure. Children with B-Pb >or= 100 microg/L were compared to those with B-Pb < 100 microg/L. Mean B-Pb was 66.0 microg/L (median 60.0; range 10-160; standard deviation 26.3) with 39 (14%) children with B-Pb >or= 100 microg/L. Logistic regression analysis showed that elevated B-Pb was associated with paternal manual jobs (odds ratio [OR]: 4.74), residence being located in high traffic areas (OR: 4.59), summer season (OR: 4.39), using hot tap water for cooking (OR: 3.96), exposure to kohl (OR: 2.40), and living in older buildings (OR: 2.01). Lead screening should be offered to high-risk children. With the recent ban of leaded gasoline in Lebanon, emphasis should shift to other sources of exposure in children.

Compatibility of an FeCrAl alloy with flowing Pb-Li in a thermal convection loop

NASA Astrophysics Data System (ADS)

Pawel, Steven J.; Unocic, Kinga A.

2017-08-01

A mono-metallic thermal convection loop (TCL) fabricated from alloy APMT (Fe21Cr5Al3Mo) tubing and filled with 0.025 m long tensile specimens of the same alloy was operated continuously for 1000 h with commercially pure Pb-17 at.%Li (Pb-Li) at a peak temperature of 550 ± 1.5 °C and a temperature gradient of ∼116 °C. The resulting Pb-Li flow rate was ∼0.0067 m/s. A 1050 °C pre-oxidation treatment (to form an external alumina scale) given to most specimens exposed within the TCL decreased total mass loss by a factor of 3-30 compared to adjacent specimens that were not pre-oxidized. However, all specimens exposed above 500 °C lost mass suggesting that the alumina scale was not entirely stable in flowing Pb-Li at these temperatures. Post-exposure room temperature tensile tests indicated that the mechanical properties of APMT were substantially influenced by extended exposures in the range of 435-490 °C, which caused an increase in yield strength (∼65%) and a corresponding decrease in ductility associated with α‧ embrittlement. Specimens annealed in argon at the same temperature exhibited identical changes without exposure to Pb-Li. Scanning transmission electron microscopy revealed Cr-clusters within the microstructure in specimens exposed in the low temperature regions (<490 °C) of the TCL, indicating the formation of α‧ consistent with the mechanism of α‧ embrittlement.

Unraveling the Reactivity of Minium toward Bicarbonate and the Role of Lead Oxides Therein.

PubMed

Ayalew, Eyasu; Janssens, Koen; De Wael, Karolien

2016-02-02

Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. For demonstrating its photoactivity, an electrochemical setup with a minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor that is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experimentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4-modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However, in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded because the PbO reacts further to form hydrocerussite. Therefore, the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process.

Evaluating the All-Ages Lead Model Using SiteSpecific Data: Approaches and Challenges

EPA Science Inventory

Lead (Pb) exposure continues to be a problem in the United States. Even after years of progress in reducing environmental levels, CDC estimates at least 500,000 U.S. children ages 1-5 years have blood Pb levels (BLL) above the CDC reference level of 5 µg/dL. Childhood Pb ex...

Are newborn rat-derived neural stem cells more sensitive to lead neurotoxicity?★

PubMed Central

Chan, Yan Ho; Gao, Mingyong; Wu, Wutian

2013-01-01

Lead ion (Pb2+) has been proven to be a neurotoxin due to its neurotoxicity on mammalian nervous system, especially for the developing brains of juveniles. However, many reported studies involved the negative effects of Pb2+ on adult neural cells of humans or other mammals, only few of which have examined the effects of Pb2+ on neural stem cells. The purpose of this study was to reveal the biological effects of Pb2+ from lead acetate [Pb (CH3COO)2] on viability, proliferation and differentiation of neural stem cells derived from the hippocampus of newborn rats aged 7 days and adult rats aged 90 days, respectively. This study was carried out in three parts. In the first part, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT viability assay) was used to detect the effects of Pb2+ on the cell viability of passage 2 hippocampal neural stem cells after 48-hour exposure to 0–200 μM Pb2+. In the second part, 10 μM bromodeoxyuridine was added into the culture medium of passage 2 hippocampal neural stem cells after 48-hour exposure to 0–200 μM Pb2+, followed by immunocytochemical staining with anti-bromodeoxyuridine to demonstrate the effects of Pb2+ on cell proliferation. In the last part, passage 2 hippocampal neural stem cells were allowed to grow in the differentiation medium with 0–200 μM Pb2+. Immunocytochemical staining with anti-microtubule-associated protein 2 (a neuron marker), anti-glial fibrillary acidic protein (an astrocyte marker), and anti-RIP (an oligodendrocyte marker) was performed to detect the differentiation commitment of affected neural stem cells after 6 days. The data showed that Pb2+ inhibited not only the viability and proliferation of rat hippocampal neural stem cells, but also their neuronal and oligodendrocyte differentiation in vitro. Moreover, increased activity of astrocyte differentiation of hippocampal neural stem cells from both newborn and adult rats was observed after exposure to high concentration of lead ion in vitro. These findings suggest that hippocampal neural stem cells of newborn rats were more sensitive than those from adult rats to Pb2+ cytotoxicity. PMID:25206702

Polyfluoroalkyl Chemicals and Learning and Developmental Disorders: Epidemiology and Exposure Assessment

ERIC Educational Resources Information Center

Hoffman, Jennifer Kate

2010-01-01

This dissertation has two areas of focus: learning and developmental disorders (LDDs) and polyfluoroalkyl chemicals (PFCs). Epidemiological and exposure assessment methods are applied to each. The first paper used geographic location as a surrogate for exposure and broadly assesses the effect of the environment, both physical and social, on LDD…

Developmental Immunotoxicity

EPA Science Inventory

Animal models suggest that the immature immune system is more susceptible to xenobiotics than the fully mature system, and sequelae of developmental immunotoxicant exposure may be persistent well into adulthood. Immune maturation may be delayed by xenobiotic exposure and recover...

Developmental cigarette smoke exposure II: Hippocampus proteome and metabolome profiles in adult offspring.

PubMed

Neal, Rachel E; Jagadapillai, Rekha; Chen, Jing; Webb, Cindy; Stocke, Kendall; Greene, Robert M; Pisano, M Michele

2016-10-01

Exposure to cigarette smoke during development is linked to neurodevelopmental delays and cognitive impairment including impulsivity, attention deficit disorder, and lower IQ. Utilizing a murine experimental model of "active" inhalation exposure to cigarette smoke spanning the entirety of gestation and through human third trimester equivalent hippocampal development [gestation day 1 (GD1) through postnatal day 21 (PD21)], we examined hippocampus proteome and metabolome alterations present at a time during which developmental cigarette smoke exposure (CSE)-induced behavioral and cognitive impairments are evident in adult animals from this model system. At six month of age, carbohydrate metabolism and lipid content in the hippocampus of adult offspring remained impacted by prior exposure to cigarette smoke during the critical period of hippocampal ontogenesis indicating limited glycolysis. These findings indicate developmental CSE-induced systemic glucose availability may limit both organism growth and developmental trajectory, including the capacity for learning and memory. Copyright © 2016 Elsevier Inc. 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 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

Effects of decabromodiphenyl ether on lead mobility and microbial toxicity in soil.

PubMed

Zhang, Wei; Chen, Lei; Zhang, Rong; Lin, Kuangfei

2015-03-01

Lead (Pb) and decabromodiphenyl ether (BDE209) are the main pollutants at e-waste recycling sites (EWRSs). Focus on joint toxicological effects of the two chemicals has increasingly gained a great amount of interest. Therefore, the lab study was performed to determine the Pb mobility and microbial toxicity in a Pb-polluted soil in the presence of BDE209 for the first time. The results showed that BDE209 was barely degraded and could elicit the combined effects with Pb exposure during the entire incubation period. The exchangeable (EXCH) and carbonates fractions of Pb were transformed to organic, Fe/Mn oxides and residual fractions, and the addition of an appropriate amount (100mgkg(-1)) of BDE209 facilitated the transformation compared with Pb alone. In addition, soil microbial biomass C (Cmic), soil basal respiration (SBR) and metabolic quotient (qCO2) increased in the beginning of the experiment and then declined with the incubation period extension, and BDE209 addition might cause notable different response relative to the control. Significant correlations between EXCH or mobility factor (MF) of Pb and SBR, Cmic, or qCO2 in soil treated with BDE209 can be clearly observed. Results of the observations provide a better understanding of ecotoxicological effects of Pb and BDE209 joint exposure on indigenous microorganisms in soil at EWRSs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spatially resolved hazard and exposure assessments: an example of lead in soil at Lavrion, Greece.

PubMed

Tristán, E; Demetriades, A; Ramsey, M H; Rosenbaum, M S; Stavrakis, P; Thornton, I; Vassiliades, E; Vergou, K

2000-01-01

Spatially resolved hazard assessment (SRHA) and spatially resolved exposure assessment (SREA) are methodologies that have been devised for assessing child exposure to soil containing environmental pollutants. These are based on either a quantitative or a semiquantitative approach. The feasibility of the methodologies has been demonstrated in a study assessing child exposure to Pb accessible in soil at the town of Lavrion in Greece. Using a quantitative approach, both measured and kriged concentrations of Pb in soil are compared with an "established" statutory threshold value. The probabilistic approach gives a refined classification of the contaminated land, since it takes into consideration the uncertainty in both the actual measurement and estimated kriged values. Two exposure assessment models (i.e., IEUBK and HESP) are used as the basis of the quantitative SREA methodologies. The significant correlation between the blood-Pb predictions, using the IEUBK model, and measured concentrations provides a partial validation of the method, because it allows for the uncertainty in the measurements and the lack of some site-specific measurements. The semiquantitative applications of SRHA and SREA incorporate both qualitative information (e.g., land use and dustiness of waste) and quantitative information (e.g., distance from wastes and distance from industry). The significant correlation between the results of these assessments and the measured blood-Pb levels confirms the robust nature of this approach. Successful application of these methodologies could reduce the cost of the assessment and allow areas to be prioritized for further investigation, remediation, or risk management.

Sub-chronic lead exposure produces β1-adrenoceptor downregulation decreasing arterial pressure reactivity in rats.

PubMed

Toscano, Cindy Medici; Simões, Maylla Ronacher; Alonso, Maria Jesus; Salaices, Mercedes; Vassallo, Dalton Valentim; Fioresi, Mirian

2017-07-01

Lead is considered a causative factor for hypertension and other cardiovascular diseases. To investigate the effects of sub-chronic lead exposure on blood pressure reactivity and cardiac β 1 -adrenoceptor activity and to evaluate whether the effects found in vitro are similar to those found in vivo. Male Wistar rats were randomly distributed into two groups: control rats (Ct) and rats administered drinking water containing 100ppm lead (Pb) for 30days. Blood pressure in the Pb rats increased starting from the first week of treatment until the end of the study [systolic blood pressure, Ct: 122±4 vs. Pb: 143±3mmHg; diastolic blood pressure, Ct: 63±4 vs. Pb: 84±4mmHg]. The heart rate was also increased (Ct: 299±11 vs. Pb: 365±11bpm), but the pressure reactivity to phenylephrine was decreased. Losartan and hexamethonium exhibited a greater reduction in blood pressure of Pb rats than in the Ct rats. Isoproterenol increased the left ventricular systolic and end-diastolic pressure, and heart rate only in Ct rats, suggesting that lead induced β 1 -adrenoceptor downregulation. Indomethacin reduced the blood pressure and heart rate in the Pb rats, suggesting the involvement of cyclooxygenase-derived products (which are associated with reduced nitric oxide bioavailability) in this process. These findings offer further evidence that the effects of sub-chronic lead exposure in vitro can be reproduced in vivo-even at low concentrations-thus triggering mechanisms for the development of hypertension. Therefore, lead should be considered an environmental risk factor for cardiovascular disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Time-response characteristic and potential biomarker identification of heavy metal induced toxicity in zebrafish.

PubMed

Yin, Jian; Wang, Ai-Ping; Li, Wan-Fang; Shi, Rui; Jin, Hong-Tao; Wei, Jin-Feng

2018-01-01

The present work aims to explore the time-response (from 24 h to 96 h) characteristic and identify early potential sensitive biomarkers of copper (Cu) (as copper chloride dihydrate), cadmium (Cd) (as cadmium acetate), lead (Pb) (as lead nitrate) and chromium (Cr) (as potassium dichromate) exposure in adult zebrafish, focusing on reactive oxygen species (ROS), SOD activity, lipid peroxidation and gene expression related to oxidative stress and inflammatory response. Furthermore, the survival rate decreased apparently by a concentration-dependent manner after Cu, Cr, Cd and Pb exposure, and we selected non-lethal concentrations 0.05 mg/L for Cu, 15 mg/L for Cr, 3 mg/L for Cd and 93.75μg/L for Pb to test the effect on the following biological indicators. Under non-lethal concentration, the four heavy metals have no apparent histological change in adult zebrafish gills. Similar trends in ROS production, MDA level and SOD activity were up-regulated by the four heavy metals, while MDA level responded more sensitive to Pb by time-dependent manner than the other three heavy metals. In addition, mRNA levels related to antioxidant system (SOD1, SOD2 and Nrf2) were up-regulated by non-lethal concentration Cu, Cr, Cd and Pb exposure. MDA level and SOD1 gene have a more delayed response to heavy metals. Genes related to immunotoxicity were increased significantly after heavy metals exposure at non-lethal concentrations. TNF-α and IL-1β gene have similar sensibility to the four heavy metals, while IL-8 gene was more responsive to Cr, Cd and Pb exposure at 48 h groups and IFN-γ gene showed more sensitivity to Cu at 48 h groups than the other heavy metals. In conclusion, the present works have suggested that the IFN-γ gene may applied as early sensitive biomarker to identify Cu-induced toxicity, while MDA content and IL-8 gene may use as early sensitive biomarkers for evaluating the risk of Pb exposure. Moreover, IL-8 and IFN-γ gene were more responsive to heavy metals, which may become early sensitive and potential biomarkers for evaluating inflammatory response induced by heavy metals. This work reinforces the concept of the usefulness of gene expression assays in the evaluation of chemicals effects and helps to establish a background data as well as contributes to evaluate early environmental risk for chemicals, even predicting toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lead and other trace metals in preeclampsia: A case-control study in Tehran, Iran

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

Vigeh, Mohsen; Yokoyama, Kazuhito; Ramezanzadeh, Fateme

2006-02-15

To assess the effects of environmental exposures to trace metals on the incidence of preeclampsia, concentrations of lead (Pb), antimony (Sb), manganese (Mn), mercury, cadmium, cobalt and zinc in umbilical cord blood (UCB) and mother whole blood (MWB) were measured in 396 postpartum women without occupational exposure to metals in Tehran, Iran, using inductively coupled plasma mass spectrometry. Mother's ages ranged from 15 to 49 (mean 27) years. Preeclampsia was diagnosed in 31 subjects (7.8%). Levels of Pb, Sb and Mn in UCB were significantly higher in preeclampsia cases [mean+/-SD of 4.30+/-2.49{mu}g/dl, 4.16+/-2.73 and 46.87+/-15.03{mu}g/l, respectively] than in controls [3.52+/-2.09{mu}g/dl,more » 3.17+/-2.68 and 40.32+/-15.19{mu}g/l, respectively] (P<0.05). The logistic regression analysis revealed that one unit increase in the common logarithms of UCB concentration of Pb, Sb or Mn led to increase in the risk of preeclampsia several-fold; unit risks (95% CI) were 12.96 (1.57-107.03), 6.11 (1.11-33.53) and 34.2 (1.81-648.04) for Pb, Sb and Mn, respectively (P<0.05). These findings suggest that environmental exposure to Pb, Sb and Mn may increase the risk of preeclampsia in women without occupational exposure; levels of metals in UCB to be sensitive indicators of female reproductive toxicity as compared with those in mother MWB. Further studies are necessary to confirm these findings, especially on Sb and Mn.« less

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

PubMed

Guney, Mert; Zagury, Gerald J

2014-01-21

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

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.

Diverse effects of lead nitrate on the proliferation, differentiation, and gene expression of stem cells isolated from a dental origin.

PubMed

Abdullah, Mariam; Rahman, Fazliny Abd; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Abu Kasim, Noor Hayaty; Musa, Sabri

2014-01-01

Lead (Pb(2+)) exposure continues to be a significant public health problem. Therefore, it is vital to have a continuous epidemiological dataset for a better understanding of Pb(2+) toxicity. In the present study, we have exposed stem cells isolated from deciduous and permanent teeth, periodontal ligament, and bone marrow to five different types of Pb(2+) concentrations (160, 80, 40, 20, and 10 µM) for 24 hours to identify the adverse effects of Pb(2+) on the proliferation, differentiation, and gene expression on these cell lines. We found that Pb(2+) treatment altered the morphology and adhesion of the cells in a dose-dependent manner. There were no significant changes in terms of cell surface phenotypes. Cells exposed to Pb(2+) continued to differentiate into chondrogenesis and adipogenesis, and a severe downregulation was observed in osteogenesis. Gene expression studies revealed a constant expression of key markers associated with stemness (Oct 4, Rex 1) and DNA repair enzyme markers, but downregulation occurred with some ectoderm and endoderm markers, demonstrating an irregular and untimely differentiation trail. Our study revealed for the first time that Pb(2+) exposure not only affects the phenotypic characteristics but also induces significant alteration in the differentiation and gene expression in the cells.

Neuronal Degeneration in the Cingulated Gyrus: NMDC Antagonists and Anticholinesterases

DTIC Science & Technology

2002-10-01

exposure of these compounds to pyridostigmine bromide induce detectable neurotoxicity. 3) The NMDA receptor antagonist, memantine induces a neurotoxic...these drug combinations, suggesting this is a toxic combination. 4) The resultant neuropathology in MK-801 and memantine exposed animals is in good...agreement with the behavioral deficits exhibited by animals exposed to these compounds. 5) Combined exposure of memantine and PB had a greater effect on IPSPs than did memantine or PB alone.

Alterations in glucocorticoid negative feedback following maternal Pb, prenatal stress and the combination: A potential biological unifying mechanism for their corresponding disease profiles

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

Rossi-George, A.; Virgolini, M.B.; Weston, D.

Combined exposures to maternal lead (Pb) and prenatal stress (PS) can act synergistically to enhance behavioral and neurochemical toxicity in offspring. Maternal Pb itself causes permanent dysfunction of the body's major stress system, the hypothalamic pituitary adrenal (HPA) axis. The current study sought to determine the potential involvement of altered negative glucocorticoid feedback as a mechanistic basis of the effects in rats of maternal Pb (0, 50 or 150 ppm in drinking water beginning 2 mo prior to breeding), prenatal stress (PS; restraint on gestational days 16-17) and combined maternal Pb + PS in 8 mo old male and femalemore » offspring. Corticosterone changes were measured over 24 h following an i.p. injection stress containing vehicle or 100 or 300 {mu}g/kg (females) or 100 or 150 {mu}g/kg (males) dexamethasone (DEX). Both Pb and PS prolonged the time course of corticosterone reduction following vehicle injection stress. Pb effects were non-monotonic, with a greater impact at 50 vs. 150 ppm, particularly in males, where further enhancement occurred with PS. In accord with these findings, the efficacy of DEX in suppressing corticosterone was reduced by Pb and Pb + PS in both genders, with Pb efficacy enhanced by PS in females, over the first 6 h post-administration. A marked prolongation of DEX effects was found in males. Thus, Pb, PS and Pb + PS, sometimes additively, produced hypercortisolism in both genders, followed by hypocortisolism in males, consistent with HPA axis dysfunction. These findings may provide a plausible unifying biological mechanism for the reported links between Pb exposure and stress-associated diseases and disorders mediated via the HPA axis, including obesity, hypertension, diabetes, anxiety, schizophrenia and depression. They also suggest broadening of Pb screening programs to pregnant women in high stress environments.« less

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish.

PubMed

Kung, Tiffany S; Richardson, Jason R; Cooper, Keith R; White, Lori A

2015-08-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25-0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3-72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish

PubMed Central

Kung, Tiffany S.; Richardson, Jason R.; Cooper, Keith R.; White, Lori A.

2015-01-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25–0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3–72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. PMID:25912032

Reproductive and Developmental Toxicity of Formaldehyde: A Systematic Review

PubMed Central

Duong, Anh; Steinmaus, Craig; McHale, Cliona M.; Vaughan, Charles P.; Zhang, Luoping

2011-01-01

Formaldehyde, the recently classified carcinogen and ubiquitous environmental contaminant, has long been suspected of causing adverse reproductive and developmental effects, but previous reviews were inconclusive, due in part, to limitations in the design of many of the human population studies. In the current review, we systematically evaluated evidence of an association between formaldehyde exposure and adverse reproductive and developmental effects, in human populations and in vivo animal studies, in the peer-reviewed literature. The mostly retrospective human studies provided evidence of an association of maternal exposure with adverse reproductive and developmental effects. Further assessment of this association by meta-analysis revealed an increased risk of spontaneous abortion (1.76, 95% CI 1.20–2.59, p=0.002) and of all adverse pregnancy outcomes combined (1.54, 95% CI 1.27–1.88, p<0.001), in formaldehyde-exposed women, although differential recall, selection bias, or confounding cannot be ruled out. Evaluation of the animal studies including all routes of exposure, doses and dosing regimens studied, suggested positive associations between formaldehyde exposure and reproductive toxicity, mostly in males. Potential mechanisms underlying formaldehyde-induced reproductive and developmental toxicities, including chromosome and DNA damage (genotoxicity), oxidative stress, altered level and/or function of enzymes, hormones and proteins, apoptosis, toxicogenomic and epigenomic effects (such as DNA methylation), were identified. To clarify these associations, well-designed molecular epidemiologic studies, that include quantitative exposure assessment and diminish confounding factors, should examine both reproductive and developmental outcomes associated with exposure in males and females. Together with mechanistic and animal studies, this will allow us to better understand the systemic effect of formaldehyde exposure. PMID:21787879

Electronic structures and chemical states of methylammonium lead triiodide thin films and the impact of annealing and moisture exposure

NASA Astrophysics Data System (ADS)

Yamanaka, Soichiro; Hayakawa, Kei; Cojocaru, Ludmila; Tsuruta, Ryohei; Sato, Tomoya; Mase, Kazuhiko; Uchida, Satoshi; Nakayama, Yasuo

2018-04-01

Methylammonium lead triiodide (CH3NH3PbI3) is the fundamental material used in perovskite solar cells, and its electronic properties have, therefore, attracted a great deal of attention as a potential key to highly efficient solar cell performance. However, the deterioration of perovskite solar cells when exposed to high temperature and humidity remains a serious obstacle to the material's use, and the clarification of the degradation mechanisms has been keenly anticipated. In this study, the valence electronic structures and depth-dependence of the chemical states of CH3NH3PbI3 thin films are investigated using ultraviolet photoelectron spectroscopy and excitation energy dependent X-ray photoelectron spectroscopy. Additionally, the effects of high temperature and a moisture rich atmosphere on the CH3NH3PbI3 thin films are examined. It is confirmed that the high temperature and moist atmosphere facilitate the oxidation of CH3NH3PbI3, whereas the Pb:I stoichiometry of the CH3NH3PbI3 thin films is found to be preserved at its original ratio (1:3) after thermal annealing and exposure to a moist atmosphere.

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

Associations between urinary phenol and paraben concentrations and markers of oxidative stress and inflammation among pregnant women in Puerto Rico.

PubMed

Watkins, Deborah J; Ferguson, Kelly K; Anzalota Del Toro, Liza V; Alshawabkeh, Akram N; Cordero, José F; Meeker, John D

2015-03-01

Phenols and parabens are used in a multitude of consumer products resulting in ubiquitous human exposure. Animal and in vitro studies suggest that exposure to these compounds may be related to a number of adverse health outcomes, as well as potential mediators such as oxidative stress and inflammation. We examined urinary phenol (bisphenol A (BPA), triclosan (TCS), benzophenone-3 (BP-3), 2,4-dichlorophenol (24-DCP), 2,5-dichlorophenol (25-DCP)) and paraben (butyl paraben (B-PB), methyl paraben (M-PB), propyl paraben (P-PB)) concentrations measured three times during pregnancy in relation to markers of oxidative stress and inflammation among participants in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) project. Serum markers of inflammation (c-reactive protein (CRP), IL-1β, IL-6, IL-10, and tumor necrosis factor-α (TNF-α)) were measured twice during pregnancy (n=105 subjects, 187 measurements) and urinary markers of oxidative stress (8-hydroxydeoxyguanosine (OHdG) and isoprostane) were measured three times during pregnancy (n=54 subjects, 146 measurements). We used linear mixed models to assess relationships between natural log-transformed exposure and outcome biomarkers while accounting for within individual correlation across study visits. After adjustment for urinary specific gravity, study visit, maternal pre-pregnancy BMI, and maternal education, an interquartile range (IQR) increase in urinary BPA was associated with 21% higher OHdG (p=0.001) and 29% higher isoprostane (p=0.0002), indicating increased oxidative stress. The adjusted increase in isoprostane per IQR increase in marker of exposure was 17% for BP-3, 27% for B-PB, and 20% for P-PB (all p<0.05). An IQR increase in triclosan (TCS) was associated with 31% higher serum concentrations of IL-6 (p=0.007), a pro-inflammatory cytokine. In contrast, IQR increases in BP-3 and B-PB were significantly associated with 16% and 18% lower CRP, a measure of systemic inflammation. Our findings suggest that exposure to BPA, select parabens, and TCS during pregnancy may be related to oxidative stress and inflammation, potential mechanisms by which exposure to these compounds may influence birth outcomes and other adverse health effects, but additional research is needed. Copyright © 2014 Elsevier GmbH. All rights reserved.

Associations between urinary phenol and paraben concentrations and markers of oxidative stress and inflammation among pregnant women in Puerto Rico

PubMed Central

Watkins, Deborah J.; Ferguson, Kelly K.; Toro, Liza V. Anzalota Del; Alshawabkeh, Akram N.; Cordero, José F.; Meeker, John D.

2014-01-01

Phenols and parabens are used in a multitude of consumer products resulting in ubiquitous human exposure. Animal and in vitro studies suggest that exposure to these compounds may be related to a number of adverse health outcomes, as well as potential mediators such as oxidative stress and inflammation. We examined urinary phenol (bisphenol A (BPA), triclosan (TCS), benzophenone-3 (BP-3), 2,4-dichlorophenol (24-DCP), 2,5-dichlorophenol (25-DCP)) and paraben (butyl paraben (B-PB), methyl paraben (M-PB), propyl paraben (P-PB)) concentrations measured three times during pregnancy in relation to markers of oxidative stress and inflammation among participants in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) project. Serum markers of inflammation (c-reactive protein (CRP), IL-1β, IL-6, IL-10, and tumor necrosis factor-α (TNF-α)) were measured twice during pregnancy (n=105 subjects, 187 measurements) and urinary markers of oxidative stress (8-hydroxydeoxyguanosine (OHdG) and isoprostane) were measured three times during pregnancy (n=54 subjects, 146 measurements). We used linear mixed models to assess relationships between natural log-transformed exposure and outcome biomarkers while accounting for within individual correlation across study visits. After adjustment for urinary specific gravity, study visit, maternal pre-pregnancy BMI, and maternal education, an interquartile range (IQR) increase in urinary BPA was associated with 21% higher OHdG (p=0.001) and 29% higher isoprostane (p=0.0002), indicating increased oxidative stress. The adjusted increase in isoprostane per IQR increase in marker of exposure was 17% for BP-3, 27% for B-PB, and 20% for P-PB (all p<0.05). An IQR increase in triclosan (TCS) was associated with 31% higher serum concentrations of IL-6 (p=0.007), a pro-inflammatory cytokine. In contrast, IQR increases in BP-3 and B-PB were significantly associated with 16% and 18% lower CRP, a measure of systemic inflammation. Our findings suggest that exposure to BPA, select parabens, and TCS during pregnancy may be related to oxidative stress and inflammation, potential mechanisms by which exposure to these compounds may influence birth outcomes and other adverse health effects, but additional research is needed. PMID:25435060

Prenatal exposure to disaster-related traumatic stress and developmental trajectories of temperament in early childhood: Superstorm Sandy pregnancy study.

PubMed

Zhang, Wei; Rajendran, Khushmand; Ham, Jacob; Finik, Jackie; Buthmann, Jessica; Davey, Kei; Pehme, Patricia M; Dana, Kathryn; Pritchett, Alexandra; Laws, Holly; Nomura, Yoko

2018-07-01

Little is known about the impact of prenatal maternal stress (PNMS) on the developmental trajectory of temperament and few studies have been able to incorporate a natural disaster as a quasi-experimental stressor. The current study investigated PNMS related to Superstorm Sandy ('Sandy'), a hurricane that struck the New York metropolitan area in October 2012, in terms of objective exposure during pregnancy, subjective stress reaction as assessed by maternal symptoms of post-traumatic stress, and their impact on the developmental changes in temperament during early childhood. A subsample of 318 mother-child dyads was drawn from the Stress in Pregnancy Study. Temperament was measured at 6, 12, 18, and 24 months of age. Objective exposure was associated with greater High-Intensity Pleasure, Approach, Perceptual Sensitivity and Fearfulness, but lower Cuddliness and Duration of Orientation at 6 months. Objective exposure and its interaction with subjective stress reaction predicted developmental changes in temperament. In particular, objective exposure was linked to greater increases in Activity Level but decreases in High-Intensity Pleasure, Approach, and Fearfulness. The combination of objective exposure and subjective stress reaction was also associated with greater increases in Activity Level. Temperament was measured solely via maternal report. Trimester-specific effects of Sandy on temperament were not examined. This is the first study to examine the effects of prenatal maternal exposure to a natural disaster on trajectories of early childhood temperament. Findings suggest that both objective stress exposure and subjective stress reaction in-utero predict developmental trajectories of temperament in early childhood. Copyright © 2018 Elsevier B.V. All rights reserved.

REPRODUCTIVE AND DEVELOPMENTAL EFFECTS IN MAMMALIAN AND AVIAN SPECIES FROM EXPOSURE TO ELF (EXTREMELY LOW FREQUENCY) FIELDS

EPA Science Inventory

This paper critically reviews the Extremely Low Frequency (ELF) Electromagnetic Fields literature from 1978 to the present in regard to research dealing with the reproductive and developmental effects of exposure.

Developmental Triclosan Exposure Decreases Maternal and Offspring Thyroxine in Rats*

EPA Science Inventory

Epidemiological and laboratory data have demonstrated that disruption of maternal thyroid hormones during fetal developmental may result in irreversible neurological consequences in offspring. In a short-term exposure paradigm, triclosan decreased systemic thyroxine (T4) concentr...

Protective role of silymarin and D-penicillamine against lead-induced liver toxicity and oxidative stress.

PubMed

Jalali, Seyedeh Missagh; Najafzadeh, Hossein; Bahmei, Sadegh

2017-06-01

This study was performed to assess hepatotoxicity and alterations in liver antioxidant defence in acute lead (Pb) exposure and the protective effects of silymarin in comparison to D-penicillamine in rats. Forty eight Albino rats were divided in eight groups and received the following treatments in a 10-day experiment - group 1: normal saline as control; group 2: 25-mg/kg Pb acetate, intraperitoneally (IP) for the last 5 days; group 3: 100-mg/kg D-penicillamine, IP for the last 5 days; group 4: 200-mg/kg silymarin, orally for 10 days; and groups 5, 6, 7 and 8: in addition to Pb, they received D-penicillamine, for the last 5 days, silymarin for 10 days, a combination of silymarin for 10 days and D-penicillamine for the last 5 days and silymarin for the last 5 days, respectively. Pb acetate exposure induced significant elevation in serum alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzyme activities in group 2 compared to control group. Significant reductions in serum total protein and albumin in all Pb-exposed groups and in serum glucose in groups 2, 6 and 8 were also observed. Liver tissue superoxide dismutase and glutathione peroxidase were significantly lower in groups 2 and 8 compared to control group. Silymarin pretreatment and D-penicillamine administration in groups 5, 7 and 8 could significantly lower ALP, ALT and AST and improve liver antioxidant enzymes. Thus, acute Pb exposure induced hepatotoxicity with suppression of liver antioxidant defence system and silymarin, as an antioxidant could alleviate this effect.

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.

Blood Lead Concentrations in 1–3 Year Old Lebanese Children: A Cross-sectional study

PubMed Central

Nuwayhid, Iman; Nabulsi, Mona; Muwakkit, Samar; Kouzi, Sarah; Salem, George; Mikati, Mohamed; Ariss, Majd

2003-01-01

Background Childhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb ≥ 100 μg/L) among 1–3 year old children. It also examines the need for universal blood lead screening. Methods This is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997–98. Blood was drawn on participating children for lead analysis and a structured questionnaire was introduced to mothers asking about social, demographic, and residence characteristics, as well as potential risk factors for lead exposure. Children with B-Pb ≥ 100 μg/L were compared to those with B-Pb < 100 μg/L. Results Mean B-Pb was 66.0 μg/L (median 60.0; range 10–160; standard deviation 26.3) with 39 (14%) children with B-Pb ≥ 100 μg/L. Logistic regression analysis showed that elevated B-Pb was associated with paternal manual jobs (odds ratio [OR]: 4.74), residence being located in high traffic areas (OR: 4.59), summer season (OR: 4.39), using hot tap water for cooking (OR: 3.96), exposure to kohl (OR: 2.40), and living in older buildings (OR: 2.01). Conclusion Lead screening should be offered to high-risk children. With the recent ban of leaded gasoline in Lebanon, emphasis should shift to other sources of exposure in children. PMID:12780938

Compatibility of an FeCrAl alloy with flowing Pb-Li in a thermal convection loop

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

Pawel, Steven J.; Unocic, Kinga A.

A mono-metallic thermal convection loop (TCL) fabricated from alloy APMT (Fe21Cr5Al3Mo) tubing and filled with 0.025 m long tensile specimens of the same alloy was operated continuously for 1000 h with commercially pure Pb-17 at.%Li (Pb-Li) at a peak temperature of 550 ± 1.5 °C and a temperature gradient of ~116 °C. The resulting Pb-Li flow rate was ~0.0067 m/s. A 1050 °C pre-oxidation treatment (to form an external alumina scale) given to most specimens exposed within the TCL decreased total mass loss by a factor of 3–30 compared to adjacent specimens that were not pre-oxidized. However, all specimens exposedmore » above 500 °C lost mass suggesting that the alumina scale was not entirely stable in flowing Pb-Li at these temperatures. Post-exposure room temperature tensile tests indicated that the mechanical properties of APMT were substantially influenced by extended exposures in the range of 435–490 °C, which caused an increase in yield strength (~65%) and a corresponding decrease in ductility associated with α' embrittlement. Specimens annealed in argon at the same temperature exhibited identical changes without exposure to Pb-Li. In conclusion, scanning transmission electron microscopy revealed Cr-clusters within the microstructure in specimens exposed in the low temperature regions (<490 °C) of the TCL, indicating the formation of α' consistent with the mechanism of α' embrittlement.« less

Compatibility of an FeCrAl alloy with flowing Pb-Li in a thermal convection loop

DOE PAGES

Pawel, Steven J.; Unocic, Kinga A.

2017-08-01

A mono-metallic thermal convection loop (TCL) fabricated from alloy APMT (Fe21Cr5Al3Mo) tubing and filled with 0.025 m long tensile specimens of the same alloy was operated continuously for 1000 h with commercially pure Pb-17 at.%Li (Pb-Li) at a peak temperature of 550 ± 1.5 °C and a temperature gradient of ~116 °C. The resulting Pb-Li flow rate was ~0.0067 m/s. A 1050 °C pre-oxidation treatment (to form an external alumina scale) given to most specimens exposed within the TCL decreased total mass loss by a factor of 3–30 compared to adjacent specimens that were not pre-oxidized. However, all specimens exposedmore » above 500 °C lost mass suggesting that the alumina scale was not entirely stable in flowing Pb-Li at these temperatures. Post-exposure room temperature tensile tests indicated that the mechanical properties of APMT were substantially influenced by extended exposures in the range of 435–490 °C, which caused an increase in yield strength (~65%) and a corresponding decrease in ductility associated with α' embrittlement. Specimens annealed in argon at the same temperature exhibited identical changes without exposure to Pb-Li. In conclusion, scanning transmission electron microscopy revealed Cr-clusters within the microstructure in specimens exposed in the low temperature regions (<490 °C) of the TCL, indicating the formation of α' consistent with the mechanism of α' embrittlement.« less

Comparative study on the hepatoprotection to heavy metals of Zingiber officinale

PubMed Central

Nwokocha, Chukwuemeka R.; Owu, Daniel U.; Nwokocha, Magdalene I.; Ufearo, Chibueze S.; Iwuala, Moses O. E.

2012-01-01

Context: Zingiber officinale (Zingiberaceae) is a herb used for culinary and therapeutic purposes due to its anti-inflammatory and antioxidant potentials. Objectives: We examined its protective ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. Materials & Methods: Ground Zingiber officinale (7%, w/w of feed) was administered to rats either at the same time with the exposure ofheavy metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. Animals were exposed to either of Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) in drinking water. The heavy metal accumulations in the liver were determined using AAS. Results: Weight losses induced by these metals were not reversed by Zingiber officinale administration. There was a significant (P<0.01) increase in protection to Pb (97%) and Cd (63%) accumulation when compared to Hg (32%) at week 2. The protective ability was significantly (P<0.01) decreased at week 4 when compared to week 2 for Cd and Pb but not to Hg in groups 3 (50%) and 4 (52%). At week 6, hepatoprotection to Hg (44%) and Cd (85%) was significantly (P<0.01) different but not to Pb which was only significant (P<0.05) in week 2 of treatment for all groups. Discussion and Conclusion: Zingiber officinale affected the bioavailability, elimination and uptake of these metals in a time-dependent way with highest beneficial reducing effect to Cd followed by Hg and least protection to Pb in the liver. PMID:23225964

Comparative study on the hepatoprotection to heavy metals of Zingiber officinale.

PubMed

Nwokocha, Chukwuemeka R; Owu, Daniel U; Nwokocha, Magdalene I; Ufearo, Chibueze S; Iwuala, Moses O E

2012-10-01

Zingiber officinale (Zingiberaceae) is a herb used for culinary and therapeutic purposes due to its anti-inflammatory and antioxidant potentials. We examined its protective ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. MATERIALS #ENTITYSTARTX00026; Ground Zingiber officinale (7%, w/w of feed) was administered to rats either at the same time with the exposure ofheavy metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. Animals were exposed to either of Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) in drinking water. The heavy metal accumulations in the liver were determined using AAS. Weight losses induced by these metals were not reversed by Zingiber officinale administration. There was a significant (P<0.01) increase in protection to Pb (97%) and Cd (63%) accumulation when compared to Hg (32%) at week 2. The protective ability was significantly (P<0.01) decreased at week 4 when compared to week 2 for Cd and Pb but not to Hg in groups 3 (50%) and 4 (52%). At week 6, hepatoprotection to Hg (44%) and Cd (85%) was significantly (P<0.01) different but not to Pb which was only significant (P<0.05) in week 2 of treatment for all groups. Zingiber officinale affected the bioavailability, elimination and uptake of these metals in a time-dependent way with highest beneficial reducing effect to Cd followed by Hg and least protection to Pb in the liver.

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.

Genotoxicity and cytotoxicity response to environmentally relevant complex metal mixture (Zn, Cu, Ni, Cr, Pb, Cd) accumulated in Atlantic salmon (Salmo salar). Part I: importance of exposure time and tissue dependence.

PubMed

Stankevičiūtė, Milda; Sauliutė, Gintarė; Svecevičius, Gintaras; Kazlauskienė, Nijolė; Baršienė, Janina

2017-10-01

Health impact of metal mixture at environment realistic concentrations are difficult to predict especially for long-term effects where cause-and-effect relationships may not be directly obvious. This study was aimed to evaluate metal mixture (Zn-0.1, Cu-0.01, Ni-0.01, Cr-0.01, Pb-0.005 and Cd-0.005 mg/L, respectively for 1, 2, 4, 7, 14 and 28 days at concentrations accepted for the inland waters in EU) genotoxicity (micronuclei, nuclear buds, nuclear buds on filament), cytotoxicity (8-shaped nuclei, fragmented-apoptotic erythrocytes), bioaccumulation, steady-state and the reference level of geno-cytotoxicity in hatchery-reared Atlantic salmon tissues. Metals accumulated mostly in gills and kidneys, to the lesser extent in the muscle. Uptake of metals from an entire mixture in the fish for 14 days is sufficient to reach steady-state Cr, Pb concentrations in all tissues; Zn, Cu-in kidneys and muscle, Ni-in liver, kidneys, muscle and Cd-in muscle. Treatment with metal mixture significantly increased summed genotoxicity levels at 7 days of exposure in peripheral blood and liver erythrocytes, at 14 days of exposure in gills and kidney erythrocytes. Significant elevation of cytotoxicity was detected after 2 and 14 days of exposure in gills erythrocytes and after 28 days-in peripheral blood erythrocytes. The amount of Cu, Cr, Pb and Cd accumulated in tissues was dependent upon duration of exposure; nuclear buds, 8-shaped nuclei frequencies also were dependent upon duration of exposure. This study indicates that metals at low levels when existing in mixture causes significant geno-cytotoxicity responses and metals bioaccumulation in salmon.

Lead and methylene chloride exposures among automotive repair technicians.

PubMed

Enander, Richard T; Cohen, Howard J; Gute, David M; Brown, Linfield C; Desmaris, Anne Marie C; Missaghian, Richard

2004-02-01

Potential exposures among repair technicians engaged in vehicle resurfacing operations prior to spray painting have not been thoroughly characterized. Environmental and personal air monitoring conducted in the State of Rhode Island have shown that automotive repair technicians may be exposed to metal particulates in sanding dust and methylene chloride vapors during vehicle paint removal operations. Hand wipe samples demonstrated that metals in sanding dust adhered to the hands of workers throughout the duration of the work day and were available for incidental ingestion from the handling of food/nonfood items and hand-to-mouth contact. A blood lead (PbB) screening effort among 21 workers at 2 facilities showed that 4 non-/less-exposed workers had mean PbB levels at the U.S. geometric mean of 2.8 microg/dL, while 2 out of 9 (22%) dedicated vehicle repair technicians had PbB levels at or above 30 microg Pb/dL whole blood--the level for potential adverse reproductive effects. Methylene chloride exposures were also found to exceed the Occupational Safety and Health Administrations (OSHA) 8-hr time-weighted average (TWA) action level and permissible exposure limit (PEL) in a limited number of samples (120 and 26 ppm, integrated work shift samples). Our findings suggest that thousands of professional technicians and vocational high school students may be at increased risk of adverse reproductive and/or other systemic effects.

The U.S. Food and Drug Administration Risk Assessment on Lead in Women’s and Children’s Vitamins Is Based on Outdated Assumptions

PubMed Central

Miodovnik, Amir; Landrigan, Philip J.

2009-01-01

Background Following a recent report of lead in certain commercial vitamin products, the U.S. Food and Drug Administration (FDA) conducted a nationwide survey to determine the Pb content in 324 multivitamin/mineral products labeled for use by women and children. The FDA compared estimated Pb exposures from each product with safe/tolerable exposure levels, termed provisional total tolerable intake (PTTI) levels, previously developed for at-risk population groups in 1992. Objective We investigated the FDA’s conclusions that Pb concentrations in all vitamin products examined do not pose a hazard to health because they are below the PTTI levels for all groups considered. Discussion For their initial estimations of PTTI levels, the FDA used a blood lead level (BLL) of 10 μg/dL as the threshold for adverse effects in children and in pregnant or lactating women. Studies have repeatedly linked chronic exposure to BLLs < 10 μg/dL with impairments in cognitive function and behavior in young children despite the absence of overt signs of toxicity. The FDA analysis also omitted any consideration of nonfood sources of Pb exposure, which is inconsistent with our current understanding of how most children develop elevated BLLs. Conclusion We feel that based on these oversights, the FDA’s conclusions are unduly reassuring and that reconsideration of their current recommendations appears warranted. PMID:19654907

Challenges in assessing the health risks of consuming vegetables in metal-contaminated environments.

PubMed

Augustsson, Anna; Uddh-Söderberg, Terese; Filipsson, Monika; Helmfrid, Ingela; Berglund, Marika; Karlsson, Helen; Hogmalm, Johan; Karlsson, Andreas; Alriksson, Stina

2018-04-01

A great deal of research has been devoted to the characterization of metal exposure due to the consumption of vegetables from urban or industrialized areas. It may seem comforting that concentrations in crops, as well as estimated exposure levels, are often found to be below permissible limits. However, we show that even a moderate increase in metal accumulation in crops may result in a significant increase in exposure. We also highlight the importance of assessing exposure levels in relation to a regional baseline. We have analyzed metal (Pb, Cd, As) concentrations in nearly 700 samples from 23 different vegetables, fruits, berries and mushrooms, collected near 21 highly contaminated industrial sites and from reference sites. Metal concentrations generally complied with permissible levels in commercial food and only Pb showed overall higher concentrations around the contaminated sites. Nevertheless, probabilistic exposure assessments revealed that the exposure to all three metals was significantly higher in the population residing around the contaminated sites, for both low-, median- and high consumers. The exposure was about twice as high for Pb and Cd, and four to six times as high for As. Since vegetable consumption alone did not result in exposure above tolerable intakes, it would have been easy to conclude that there is no risk associated with consuming vegetables grown near the contaminated sites. However, when the increase in exposure is quantified, its potential significance is harder to dismiss - especially when considering that exposure via other routes may be elevated in a similar way. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evolution of Photoluminescence, Raman, and Structure of CH3NH3PbI3 Perovskite Microwires Under Humidity Exposure

NASA Astrophysics Data System (ADS)

Segovia, Rubén; Qu, Geyang; Peng, Miao; Sun, Xiudong; Shi, Hongyan; Gao, Bo

2018-03-01

Self-assembled organic-inorganic CH3NH3PbI3 perovskite microwires (MWs) upon humidity exposure along several weeks were investigated by photoluminescence (PL) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD). We show that, in addition to the common perovskite decomposition into PbI2 and the formation of a hydrated phase, humidity induced a gradual PL redshift at the initial weeks that is stabilized for longer exposure ( 21 nm over the degradation process) and an intensity enhancement. Original perovskite Raman band and XRD reflections slightly shifted upon humidity, indicating defects formation and structure distortion of the MWs crystal lattice. By correlating the PL, Raman, and XRD results, it is believed that the redshift of the MWs PL emission was originated from the structural disorder caused by the incorporation of H2O molecules in the crystal lattice and radiative recombination through moisture-induced subgap trap states. Our study provides insights into the optical and structural response of organic-inorganic perovskite materials upon humidity exposure.

Toxicity of Metals to a Freshwater Snail, Melanoides tuberculata

PubMed Central

Shuhaimi-Othman, M.; Nur-Amalina, R.; Nadzifah, Y.

2012-01-01

Adult freshwater snails Melanoides tuberculata (Gastropod, Thiaridae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC50 values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L−1, respectively. Cu was the most toxic metal to M. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al). Metals bioconcentration in M. tuberculata increases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor) in the soft tissues. A comparison of LC50 values for metals for this species with those for other freshwater gastropods reveals that M. tuberculata is equally sensitive to metals. PMID:22666089

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.

78 FR 53039 - Pyraclostrobin; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-28

... behavior changes were not observed. In the rat developmental toxicity study, developmental toxicity... requires EPA to give special consideration to exposure of infants and children to the pesticide chemical... result to infants and children from aggregate exposure to the pesticide chemical residue...

Lead (Pb) in biota and perceptions of Pb exposure at a recently designated Superfund beach site in New Jersey.

PubMed

Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

2012-01-01

The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did.

LEAD (Pb) IN BIOTA AND PERCEPTIONS OF Pb EXPOSURE AT A RECENTLY DESIGNATED SUPERFUND BEACH SITE IN NEW JERSEY

PubMed Central

Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

2014-01-01

The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did. PMID:22409490

Inhalation developmental toxicology studies: Teratology study of n-hexane in mice: Final report

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

Mast, T.J.; Decker, J.R.; Stoney, K.H.

Gestational exposure to n-hexane resulted in an increase in the number of resorbed fetuses for exposure groups relative to the control group; however, the increases were not directly correlated to exposure concentration. The differences were statistically significant for the 200-ppM with respect to total intrauterine death (early plus late resorptions), and with respect to late resorptions for the 5000-ppM group. A small, but statistically significant, reduction in female (but not male) fetal body weight relative to the control group was observed at the 5000-ppM exposure level. There were no exposure-related increases in any individual fetal malformation or variation, nor wasmore » there any increase in the incidence of combined malformations or variations. Gestational exposure of CD-1 mice to n-hexane vapors appeared to cause a degree of concentration-related developmental toxicity in the absence of overt maternal toxicity, but the test material was not found to be teratogenic. This developmental toxicity was manifested as an increase in the number of resorptions per litter for all exposure levels, and as a decrease in the uterine: extra-gestational weight gain ratio at the 5000-ppM exposure level. Because of the significant increase in the number of resorptions at the 200-ppM exposure level, a no observable effect level (NOEL) for developmental toxicity was not established for exposure of mice to 200, 1000 or 5000-ppM n-hexane vapors. 21 refs., 3 figs., 9 tabs.« less

The Impact of the Developmental Timing of Trauma Exposure on PTSD Symptoms and Psychosocial Functioning among Older Adults

ERIC Educational Resources Information Center

Ogle, Christin M.; Rubin, David C.; Siegler, Ilene C.

2013-01-01

The present study examined the impact of the developmental timing of trauma exposure on posttraumatic stress disorder (PTSD) symptoms and psychosocial functioning in a large sample of community-dwelling older adults (N = 1,995). Specifically, we investigated whether the negative consequences of exposure to traumatic events were greater for traumas…

Decompression sickness after air break in prebreathe described with a survival model.

PubMed

Conkin, Johnny

2011-06-01

A perception exists in aerospace that a brief interruption in a 100% oxygen prebreathe (PB) by breathing air has a substantial decompression sickness (DCS) consequence. The consequences of an air break during PB on the subsequent hypobaric DCS outcomes were evaluated. The hypothesis was that asymmetrical and not symmetrical nitrogen (N2) kinetics was best to model the distribution of subsequent DCS survival times after PBs that included air breaks. DCS survival times from 95 controls for a 60-min PB prior to 2- or 4-h exposures to 4.37 psia (9144 m; 30,000 ft) were analyzed along with 3 experimental conditions: 10-min air break (N = 40), 20-min air break (N = 40), or 60-min air break (N = 32) 30 min into the PB followed by 30 min of PB. Ascent rate was 1524 m x min(-1) and all 207 exposures included light exercise at 4.37 psia. Various computations of decompression dose were evaluated; either the difference or ratio of P1N2 and P2, where P1N2 was computed tissue N2 pressure to account for the PB and P2 was altitude pressure. Survival times were described with an accelerated log logistic model with asymmetrical N2 kinetics defining P1N2--P2 as best decompression dose. Exponential N2 uptake during the air break was described with a 10-min half time and N2 elimination during PB with a 60-min half time. A simple conclusion about compensation for air break is not possible because the duration and location of a break in a PB is variable. The resulting survival model is used to compute additional PB time to compensate for an air break in PB within the range of tested conditions.

Geochemical Weathering Increases Lead Bioaccessibility in Semi-Arid Mine Tailings

PubMed Central

Hayes, Sarah M.; Webb, Sam M.; Bargar, John R.; O'Day, Peggy A.; Maier, Raina M.; Chorover, Jon

2012-01-01

Mine tailings can host elevated concentrations of toxic metal(loid)s that represent a significant hazard to surrounding communities and ecosystems. Eolian transport, capable of translocating small (micrometer-sized) particles, can be the dominant mechanism of toxic metal dispersion in arid or semi-arid landscapes. Human exposure to metals can then occur via direct inhalation or ingestion of particulates. The fact that measured doses of total lead (Pb) in geomedia correlate poorly with blood Pb levels highlights a need to better resolve the precise distribution of molecularly-speciated metal-bearing phases in the complex particle mixtures. Species distribution controls bioaccessibility, thereby directly impacting health risk. This study seeks to correlate Pb-containing particle size and mineral composition with lability and bioaccessibility in mine tailings subjected to weathering in a semi-arid environment. We employed X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF), coupled with sequential chemical extractions, to study Pb speciation in tailings from the semi-arid Arizona Klondyke State Superfund Site. Representative samples ranging in pH from 2.6 to 5.4 were selected for in-depth study of Pb solid-phase speciation. The principle lead-bearing phase was plumbojarosite (PbFe6(SO4)4(OH)12), but anglesite (PbSO4) and iron oxide-sorbed Pb were also observed. Anglesite, the most bioavailable mineral species of lead identified in this study, was enriched in surficial tailings samples, where Pb concentrations in the clay size fraction were 2–3 times higher by mass relative to bulk. A mobile and bioaccessible Pb phase accumulates in surficial tailings, with a corresponding increase in risk of human exposure to atmospheric particles. PMID:22553941

Ginger extract modulates Pb-induced hepatic oxidative stress and expression of antioxidant gene transcripts in rat liver.

PubMed

Mohamed, Omnia Ismail; El-Nahas, Abeer Fekry; El-Sayed, Yasser Said; Ashry, Khaled Mohamed

2016-07-01

Spices and herbs are recognized sources of natural antioxidants that can protect from oxidative stress, thus play an important role in chemoprevention of liver diseases. Ginger is used worldwide primarily as a spicy condiment. This study evaluated the ability of ginger extract (GE) to ameliorate oxidative-hepatic toxicity induced by lead acetate (PbAc) in rats. Five groups of animals were used: group I kept as control; groups II, IV, and V received PbAc (1 ppm in drinking water daily for 6 weeks, and kept for an additional 2 weeks without PbAc exposure); group III treated orally with GE (350 mg/kg body weight, 4 d per week) for 6 weeks; group IV (protective) received GE for 2 weeks before and simultaneously with PbAc; and group V (treatment) received GE for 2 weeks after PbAc exposure. GC-MS analysis of GE revealed its content of gingerol (7.09%), quercetin (3.20%), dl-limonene (0.96%), and zingiberene (0.18%). Treatment of PbAc-treated rats with GE has no effect on hepatic Pb concentrations. However, it maintained serum aspartate aminotransferase level, increased hepatic glutathione (157%), glutathione S-transferase (GST) (228%), glutathione peroxidase (GPx) (138%) and catalase (CAT) (112%) levels, and reduced hepatic malondialdehyde (80%). Co-treatment of PbAc group with GE upregulated mRNA expression of antioxidant genes: GST-α1 (1.4-fold), GPx1 (1.8-fold), and CAT (8-fold), while post-treatment with GE upregulated only mRNA expression of GPx1 (1.5-fold). GE has an antioxidant protective efficacy against PbAc-induced hepatotoxicity, which appears more effective than its therapeutic application. However, the changes in antioxidant gene expression were not reflected at the protein level.

Associations between soil lead concentrations and populations by race/ethnicity and income-to-poverty ratio in urban and rural areas.

PubMed

Aelion, C Marjorie; Davis, Harley T; Lawson, Andrew B; Cai, Bo; McDermott, Suzanne

2013-02-01

Lead (Pb) is a well-studied environmental contaminant that has many negative health effects, especially for children. Both racial/ethnic and income disparities have been documented with respect to exposure to Pb in soils. The objectives of this study were to assess whether soil Pb concentrations in rural and urban areas of South Carolina USA, previously identified as having clusters of intellectual disabilities (ID) in children, were positively associated with populations of minority and low-income individuals and children (≤ 6 years of age). Surface soils from two rural and two urban areas with identified clusters of ID were analyzed for Pb and concentrations were spatially interpolated using inverse distance weighted analysis. Population race/ethnicity and income-to-poverty ratio (ITPR) from United States Census 2000 block group data were aerially interpolated by block group within each area. Urban areas had significantly higher concentrations of Pb than rural areas. Significant positive associations between black, non-Hispanic Latino, individuals and children ≤ 6 years of age and mean estimated Pb concentrations were observed in both urban (r = 0.38, p = 0.0007) and rural (r = 0.53, p = 0.04) areas. Significant positive associations also were observed between individuals and children with an ITPR < 1.00 and Pb concentrations, though primarily in urban areas. Racial/ethnic minorities and low ITPR individuals, including children, may be at elevated risk for exposure to Pb in soils.

Role of manganese oxides in the exposure of mute swans (Cygnus olor) to Pb and other elements in the Chesapeake Bay, USA

USGS Publications Warehouse

Beyer, W.N.; Day, D.

2004-01-01

The aims of this study are to estimate exposure of waterfowl to elements in contaminated sediments in the Chesapeake Bay and to consider the potential role of Mn in influencing bioavailability and exposure. Mute swans living on the Aberdeen Proving Ground were collected and samples of swan digesta were analyzed and compared to samples of feces collected from mute swans living at a nearby reference site. Sediments from the proving ground had elevated concentrations of Cu, S, Se, Zn, As, Co, Cr, Hg and Pb, but concentrations of only the first four of these elements were elevated in swan digesta. Sediments from the proving ground had an elevated mean concentration of total As, about seven times the concentration at the reference site, but the swans from that site were not ingesting more As than were reference swans. Swans at both sites were feeding on submerged aquatic vegetation and ingested about 4% sediment at the proving ground and about 5% sediment at the reference site. None of the concentrations detected in the digesta or livers of the swans was considered toxic, although the concentrations of Cu and Se were high compared to those concentrations reported in other waterfowl. A remarkably high mean concentration of Mn (6900 mg/kg, dry weight) detected in the feces of the reference swans was attributed to the deposition of manganese oxides on vegetation. The ingestion of Pb by swans at the reference site was correlated with Mn and Fe concentrations, rather than with markers of sediment ingestion. The Pb was presumably scavenged by Mn and Fe oxides from the water and deposited on the surface of vegetation. Under some environmental chemical conditions, this route of exposure for Pb is more important than sediment ingestion, which was previously thought to be the main route of exposure.

Subcellular partitioning of metals in Aporrectodea caliginosa along a gradient of metal exposure in 31 field-contaminated soils.

PubMed

Beaumelle, Léa; Gimbert, Frédéric; Hedde, Mickaël; Guérin, Annie; Lamy, Isabelle

2015-07-01

Subcellular fractionation of metals in organisms was proposed as a better way to characterize metal bioaccumulation. Here we report the impact of a laboratory exposure to a wide range of field-metal contaminated soils on the subcellular partitioning of metals in the earthworm Aporrectodea caliginosa. Soils moderately contaminated were chosen to create a gradient of soil metal availability; covering ranges of both soil metal contents and of several soil parameters. Following exposure, Cd, Pb and Zn concentrations were determined both in total earthworm body and in three subcellular compartments: cytosolic, granular and debris fractions. Three distinct proxies of soil metal availability were investigated: CaCl2-extractable content dissolved content predicted by a semi-mechanistic model and free ion concentration predicted by a geochemical speciation model. Subcellular partitionings of Cd and Pb were modified along the gradient of metal exposure, while stable Zn partitioning reflected regulation processes. Cd subcellular distribution responded more strongly to increasing soil Cd concentration than the total internal content, when Pb subcellular distribution and total internal content were similarly affected. Free ion concentrations were better descriptors of Cd and Pb subcellular distribution than CaCl2 extractable and dissolved metal concentrations. However, free ion concentrations and soil total metal contents were equivalent descriptors of the subcellular partitioning of Cd and Pb because they were highly correlated. Considering lowly contaminated soils, our results raise the question of the added value of three proxies of metal availability compared to soil total metal content in the assessment of metal bioavailability to earthworm. Copyright © 2015 Elsevier B.V. All rights reserved.

Maternal exposure to the holocaust and health complaints in offspring.

PubMed

Flory, Janine D; Bierer, Linda M; Yehuda, Rachel

2011-01-01

Although the link between chronic stress and the development of cardiovascular and metabolic diseases of adulthood has been known for some time, there is growing recognition that early environmental influences may result in developmental programming via epigenetic mechanisms, thereby affecting the developmental trajectory of disease progression. Previous studies support the idea that offspring of Holocaust survivors may have been subjected to early developmental programming. We evaluated the relationship between parental exposure to the Holocaust and self-reported health ratings and disorders made by their adult offspring (i.e., second generation Holocaust survivors). A total of 137 subjects were evaluated. Regression analyses demonstrated that maternal but not paternal exposure to the Holocaust was related to poorer subjective impressions of emotional and physical health. This relationship was diminished when the offspring's own level of trait anxiety was considered. Offspring with maternal, but not paternal, Holocaust exposure also reported greater use of psychotropic and other medications, including medications for the treatment of hypertension and lipid disorders. The mechanism linking these health outcomes and maternal exposure deserves further investigation, including the possibility that fetal or early developmental programming is involved.

Maternal Exposure to the Holocaust and Health Complaints in Offspring

PubMed Central

Flory, Janine D.; Bierer, Linda M.; Yehuda, Rachel

2011-01-01

Although the link between chronic stress and the development of cardiovascular and metabolic diseases of adulthood has been known for some time, there is growing recognition that early environmental influences may result in developmental programming via epigenetic mechanisms, thereby affecting the developmental trajectory of disease progression. Previous studies support the idea that offspring of Holocaust survivors may have been subjected to early developmental programming. We evaluated the relationship between parental exposure to the Holocaust and self-reported health ratings and disorders made by their adult offspring (i.e., second generation Holocaust survivors). A total of 137 subjects were evaluated. Regression analyses demonstrated that maternal but not paternal exposure to the Holocaust was related to poorer subjective impressions of emotional and physical health. This relationship was diminished when the offspring’s own level of trait anxiety was considered. Offspring with maternal, but not paternal, Holocaust exposure also reported greater use of psychotropic and other medications, including medications for the treatment of hypertension and lipid disorders. The mechanism linking these health outcomes and maternal exposure deserves further investigation, including the possibility that fetal or early developmental programming is involved. PMID:21508517

Photosynthesis light-independent reactions are sensitive biomarkers to monitor lead phytotoxicity in a Pb-tolerant Pisum sativum cultivar.

PubMed

Rodriguez, Eleazar; da Conceição Santos, Maria; Azevedo, Raquel; Correia, Carlos; Moutinho-Pereira, José; Ferreira de Oliveira, José Miguel Pimenta; Dias, Maria Celeste

2015-01-01

Lead (Pb) environmental contamination remains prevalent. Pisum sativum L. plants have been used in ecotoxicological studies, but some cultivars showed to tolerate and accumulate some levels of Pb, opening new perspectives to their use in phytoremediation approaches. However, the putative use of pea plants in phytoremediation requires reliable toxicity endpoints. Here, we evaluated the sensitivity of a large number of photosynthesis-related biomarkers in Pb-exposed pea plants. Plants (cv. "Corne de Bélier") were exposed to Pb concentrations up to 1,000 mg kg(-1) soil during 28 days. The photosynthetic potential biomarkers that were analyzed included pigments, chlorophyll (Chl) a fluorescence, gas exchange, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) activity, and carbohydrates. Flow cytometry (FCM) was also used to assess the morpho-functional status of chloroplasts. Finally, Pb-induced nutrient disorders were also evaluated. Net CO2 assimilation rate (A) and RuBisCO activity decreased strongly in Pb-exposed plants. Plant dry mass (DM) accumulation, however, was only reduced in the higher Pb concentrations tested (500 and 1,000 mg kg(-1) soil). Pigment contents increased solely in plants exposed to the largest Pb concentration, and in addition, the parameters related to the light-dependent reactions of photosynthesis, Fv/Fm and ΦPSII, were not affected by Pb exposure. In contrast to this, carbohydrates showed an overall tendency to increase in Pb-exposed plants. The morphological status of chloroplasts was affected by Pb exposure, with a general trend of volume decrease and granularity increase. These results point the endpoints related to the light-independent reactions of photosynthesis as more sensitive predictors of Pb-toxicity than the light-dependent reactions ones. Among the endpoints related to the light-independent photosynthesis reactions, RuBisCO activity and A were found to be the most sensitive. We discuss here the advantages of using these parameters as biomarkers for Pb toxicity in plants. Finally, we report that, despite showing physiological disorders, these cultivar plants survived and accumulated high doses of Pb, and their use in environmental/decontamination studies is open to debate.

Identification of developmentally toxic drinking water disinfection byproducts and evaluation of data relevant to mode of action

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

Colman, Joan; Rice, Glenn E., E-mail: rice.glenn@epa.gov; Wright, J. Michael

Reactions between chemicals used to disinfect drinking water and compounds present in source waters produce chemical mixtures containing hundreds of disinfection byproducts (DBPs). Although the results have been somewhat inconsistent, some epidemiological studies suggest associations may exist between DBP exposures and adverse developmental outcomes. The potencies of individual DBPs in rodent and rabbit developmental bioassays suggest that no individual DBP can account for the relative risk estimates reported in the positive epidemiologic studies, leading to the hypothesis that these outcomes could result from the toxicity of DBP mixtures. As a first step in a mixtures risk assessment for DBP developmentalmore » effects, this paper identifies developmentally toxic DBPs and examines data relevant to the mode of action (MOA) for DBP developmental toxicity. We identified 24 developmentally toxic DBPs and four adverse developmental outcomes associated with human DBP exposures: spontaneous abortion, cardiovascular defects, neural tube defects, and low birth weight infancy. A plausible MOA, involving hormonal disruption of pregnancy, is delineated for spontaneous abortion, which some epidemiologic studies associate with total trihalomethane and bromodichloromethane exposures. The DBP data for the other three outcomes were inadequate to define key MOA steps.« less

Developmental Effects of Acute, Chronic, and Withdrawal from Chronic Nicotine on Fear Conditioning

PubMed Central

Portugal, George S.; Wilkinson, Derek S.; Turner, Jill R.; Blendy, Julie A.; Gould, Thomas J.

2012-01-01

Pre-adolescence and adolescence are developmental periods associated with increased vulnerability for tobacco addiction, and exposure to tobacco during these periods may lead to long-lasting changes in behavioral and neuronal plasticity. The present study examined the short- and long-term effects of nicotine and nicotine withdrawal on fear conditioning in pre-adolescent, adolescent, and adult mice, and potential underlying substrates that may mediate the developmental effects of nicotine, such as changes in nicotinic acetylcholine receptor (nAChR) binding, CREB expression, and nicotine metabolism. Age-related differences existed in sensitivity to the effects of acute nicotine, chronic nicotine and nicotine withdrawal on contextual fear conditioning (no changes in cued fear conditioning were seen); younger mice were more sensitive to the acute effects and less sensitive to the effects of nicotine withdrawal 24 hours post treatment cessation. Developmental differences in nAChR binding were associated with the effects of nicotine withdrawal on contextual learning. Developmental differences in nicotine metabolism and CREB expression were also observed, but were not related to the effects of nicotine withdrawal on contextual learning 24 hours post treatment. Chronic nicotine exposure during pre-adolescence or adolescence, however, produced long-lasting impairments in contextual learning that were observed during adulthood, whereas adult chronic nicotine exposure did not. These developmental effects could be related to changes in CREB. Overall, there is a developmental shift in the effects of nicotine on hippocampus-dependent learning and developmental exposure to nicotine results in adult cognitive deficits; these changes in cognition may play an important role in the development and maintenance of nicotine addiction. PMID:22521799

Research Models in Developmental Behavioral Toxicology.

ERIC Educational Resources Information Center

Dietrich, Kim N.; Pearson, Douglas T.

Developmental models currently used by child behavioral toxicologists and teratologists are inadequate to address current issues in these fields. Both child behavioral teratology and toxicology scientifically study the impact of exposure to toxic agents on behavior development: teratology focuses on prenatal exposure and postnatal behavior…

Changes in serial blood lead levels during pregnancy.

PubMed Central

Rothenberg, S J; Karchmer, S; Schnaas, L; Perroni, E; Zea, F; Fernández Alba, J

1994-01-01

The first step in modeling lead kinetics during pregnancy includes a description of sequential maternal blood lead (PbB) during pregnancy and the factors controlling it. We analyzed PbB of 105 women living in the Valley of Mexico from week 12 to week 36 of pregnancy and again at parturition. We also used data from all women contributing blood at any stage of pregnancy to determine antecedents of PbB. Pregnancies were uneventful, and offspring were normal. Although geometric mean PbB level averaged around 7.0 micrograms/dl (0.34 mumol/l), with a range of 1.0-35.5 micrograms/dl throughout pregnancy, analysis of variance revealed a significant decrease in mean PbB from week 12 to week 20 (1.1 micrograms/dl) and various significant increases in mean PbB from week 20 to parturition (1.6 micrograms/dl). Regression analyses confirmed the positive linear PbB trend from 20 weeks to parturition and additional contributions of dietary calcium, reproductive history, lifetime residence of Mexico City, coffee drinking, and use of indigenous lead-glazed pottery. Although decreasing hematocrit has been suggested to explain first-half pregnancy PbB decrease, the time course of hematocrit decrease in the present study did not match the sequential changes in PbB. While hemodilution and organ growth in the first half of pregnancy may account for much of the PbB decrease seen between 12 and 20 weeks, the remaining hemodilution and accelerated organ growth of the last half of pregnancy do not predict the trend toward increasing maternal PbB concentration from 20 weeks to delivery. Mobilization of bone lead, increased gut absorption, and increased retention of lead may explain part of the upward PbB trend in the second half of pregnancy. Reduction of lifetime lead exposure may be required to decrease risk of fetal exposure. Images Figure 1. Figure 2. PMID:9644197

Neurodevelopmental Low-dose Bisphenol A Exposure Leads to Early Life-stage Hyperactivity and Learning Deficits in Adult Zebrafish

PubMed Central

Saili, Katerine S.; Corvi, Margaret M.; Weber, Daniel N.; Patel, Ami U.; Das, Siba R.; Przybyla, Jennifer; Anderson, Kim A.; Tanguay, Robert L.

2011-01-01

Developmental bisphenol A (BPA) exposure has been implicated in adverse behavior and learning deficits. The mode of action underlying these effects is unclear. The zebrafish model was employed to investigate the neurobehavioral effects of developmental bisphenol A (BPA) exposure. The objectives of this study were to identify whether low-dose, developmental BPA exposure affects larval zebrafish locomotor behavior and whether learning deficits occur in adults exposed during development. Two control compounds, 17β-estradiol (an estrogen receptor ligand) and GSK4716 (a synthetic estrogen related receptor gamma ligand), were included. Larval toxicity assays were used to determine appropriate BPA, 17β-estradiol, and GSK4716 concentrations for behavior testing. BPA tissue uptake was analyzed using HPLC and lower doses were extrapolated using a linear regression analysis. Larval behavior tests were conducted using a ViewPoint Zebrabox. Adult learning tests were conducted using a custom-built T-maze. BPA exposure to ≤30 μM was nonteratogenic in zebrafish. Neurodevelopmental BPA exposure to 0.01, 0.1, or 1 μM led to larval hyperactivity or learning deficits in adult zebrafish. Exposure to 0.1 μM 17β-estradiol or GSK4716 also led to larval hyperactivity. This study demonstrates the efficacy of using the larval zebrafish model for studying the neurobehavioral effects of low-dose developmental BPA exposure. PMID:22108044

Gene expression profiles in the cerebellum and hippocampus following exposure to a neurotoxicant, Aroclor 1254: Developmental effects

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

Royland, Joyce E.; Wu, Jinfang; Zawia, Nasser H.

2008-09-01

The developmental consequences of exposure to the polychlorinated biphenyls (PCBs) have been widely studied, making PCBs a unique model to understand issues related to environmental mixture of persistent chemicals. PCB exposure in humans adversely affects neurocognitive development, causes psychomotor difficulties, and contributes to attention deficits in children, all of which seem to be associated with altered patterns of neuronal connectivity. In the present study, we examined gene expression profiles in the rat nervous system following PCB developmental exposure. Pregnant rats (Long-Evans) were dosed perinatally with 0 or 6 mg/kg/day of Aroclor 1254 from gestation day 6 through postnatal day (PND)more » 21. Gene expression in cerebellum and hippocampus from PND7 and PND14 animals was analyzed with an emphasis on developmental aspects. Changes in gene expression ({>=} 1.5 fold) in control animals identified normal developmental changes. These basal levels of expression were compared to data from Aroclor 1254-treated animals to determine the impact of gestational PCB exposure on developmental parameters. The results indicate that the expression of a number of developmental genes related to cell cycle, synaptic function, cell maintenance, and neurogenesis is significantly altered from PND7 to PND14. Aroclor 1254 treatment appears to dampen the overall growth-related gene expression levels in both regions with the effect being more pronounced in the cerebellum. Functional analysis suggests that Aroclor 1254 delays maturation of the developing nervous system, with the consequences dependent on the ontological state of the brain area and the functional role of the individual gene. Such changes may underlie learning and memory deficits observed in PCB exposed animals and humans.« less

Fluctuating asymmetry and mentum gaps in populations of the midge Chironomus riparius (Diptera: Chironomidae) from a metal-contaminated River

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

Groenendijk, D.; Zeinstra, L.W.M.; Postma, J.F.

1998-10-01

The developmental stability of both metal-exposed and nonexposed Chironomus riparius populations from the lowland River Dommel was investigated using fluctuating asymmetry (FA) and the incidence of mentum gaps. It was hypothesized that larval development was affected by the influx of Cd, Zn, Fe, Cu, and Pb directly by chemical stress, as well as through inbreeding of metal-adapted and nonadapted specimens. Morphological para/meters were therefore assessed in field-collected larvae and in clean, laboratory-cultured, first-generation (F1) larvae. Fluctuating asymmetry values and mentum gap incidence at contaminated field sites were significantly higher than at clean, upstream locations. Furthermore, FA values of clean, laboratory-culturedmore » F1 larvae generally fell to reference values, indicating the direct effect of metal pollution on developmental aberrations. Mentum gaps were not observed in clean F1 cultures. Slightly elevated FA values were, however, still observed in clean F1 larvae from polluted locations downstream from the metal input. This residual disturbance was thought to reflect genetic stress emerging from interbreeding between metal-adapted and nonadapted specimens. Fluctuating asymmetry and mentum gaps together serve as a useful ecotoxicological marker for metal stress and, when combined with in situ studies and F1 cultures, allow for analysis of the response of animal populations to spatial and temporal gradients in metal exposure.« less

Developmental origins of epigenetic transgenerational inheritance

PubMed Central

Hanson, Mark A.; Skinner, Michael K.

2016-01-01

Abstract Environmental factors can induce epigenetic alterations in the germ cells that can potentially be transmitted transgenerationally. This non-genetic form of inheritance is termed epigenetic transgenerational inheritance and has been shown in a variety of species including plants, flies, worms, fish, rodents, pigs, and humans. This phenomenon operates during specific critical windows of exposure, linked to the developmental biology of the germ cells (sperm and eggs). Therefore, concepts of the developmental origins of transgenerational inheritance of phenotypic variation and subsequent disease risk need to include epigenetic processes affecting the developmental biology of the germ cell. These developmental impacts on epigenetic transgenerational inheritance, in contrast to multigenerational exposures, are the focus of this Perspective. PMID:27390622

Lead Speciation in Microorganisms.

PubMed

Stewart, Theodora J

2017-04-10

The biogeochemical cycles of lead (Pb) have been largely affected by anthropogenic activities as a result of its high natural abundance and use over the centuries [1]. At sites more strongly impacted by urbanization [2] and mining [3], Pb is found at high nano to low micromolar concentrations in surface waters, and can be significantly higher in soil and sediment [4]. Microorganisms are found everywhere and their responses to Pb exposure can range from resistant to highly sensitive [5, 6]. These varying levels of toxicity can be attributed to the cellular handling of Pb, making it important to understand the role of intracellular Pb speciation for more accurate toxicity predictions.

Exposure to an organophosphate pesticide, individually or in combination with other Gulf War agents, impairs synaptic integrity and neuronal differentiation, and is accompanied by subtle microvascular injury in a mouse model of Gulf War agent exposure.

PubMed

Ojo, Joseph O; Abdullah, Laila; Evans, James; Reed, Jon Mike; Montague, Hannah; Mullan, Michael J; Crawford, Fiona C

2014-04-01

Gulf War illness (GWI) is a currently untreatable multi-symptom disorder experienced by 1990-1991 Persian Gulf War (GW) veterans. The characteristic hallmarks of GWI include cognitive dysfunction, tremors, migraine, and psychological disturbances such as depression and anxiety. Meta-analyses of epidemiological studies have consistently linked these symptomatic profiles to the combined exposure of GW agents such as organophosphate-based and pyrethroid-based pesticides (e.g. chlorpyrifos (CPF) and permethrin (PER) respectively) and the prophylactic use of pyridostigmine bromide (PB) as a treatment against neurotoxins. Due to the multi-symptomatic presentation of this illness and the lack of available autopsy tissue from GWI patients, very little is currently known about the distinct early pathological profile implicated in GWI (including its influence on synaptic function and aspects of neurogenesis). In this study, we used preclinical models of GW agent exposure to investigate whether 6-month-old mice exposed to CPF alone, or a combined dose of CPF, PB and PER daily for 10 days, demonstrate any notable pathological changes in hippocampal, cortical (motor, piriform) or amygdalar morphometry. We report that at an acute post-exposure time point (after 3 days), both exposures resulted in the impairment of synaptic integrity (reducing synaptophysin levels) in the CA3 hippocampal region and altered neuronal differentiation in the dentate gyrus (DG), demonstrated by a significant reduction in doublecortin positive cells. Both exposures also significantly increased astrocytic GFAP immunoreactivity in the piriform cortex, motor cortex and the basolateral amygdala and this was accompanied by an increase in (basal) brain acetylcholine (ACh) levels. There was no evidence of microglial activation or structural deterioration of principal neurons in these regions following exposure to CPF alone or in combination with PB and PER. Evidence of subtle microvascular injury was demonstrated by the reduction of platelet endothelial cell adhesion molecule (PECAM)-1 levels in CPF+PB+PER exposed group compared to control. These data support early (subtle) neurotoxic effects on the brain following exposure to GW agents. © 2013 Japanese Society of Neuropathology.

MOLECULAR AND MORPHOLOGICAL CHANGES IN ZEBRAFISH FOLLOWING TRANSIENT ETHANOL EXPOSURE DURING DEFINED DEVELOPMENTAL STAGES

PubMed Central

Zhang, Chengjin; Frazier, Jared M.; Chen, Hao; Liu, Yao; Lee, Ju-Ahng; Cole, Gregory J.

2014-01-01

Alcohol is a teratogen that has diverse effects on brain and craniofacial development, leading to a constellation of developmental disorders referred to as fetal alcohol spectrum disorder (FASD). The molecular basis of ethanol insult remains poorly understood, as does the relationship between molecular and behavioral changes as a consequence of prenatal ethanol exposure. Zebrafish embryos were exposed to a range of ethanol concentrations (0.5–5.0%) during defined developmental stages, and examined for morphological phenotypes characteristic of FASD. Embryos were also analyzed by in situ hybridization for changes in expression of defined cell markers for neural cell types that are sonic hedgehog-dependent. We show that transient binge-like ethanol exposures during defined developmental stages, such as early gastrulation and early neurulation, result in a range of phenotypes and changes in expression of Shh-dependent genes. The severity of fetal alcohol syndrome (FAS) morphological phenotypes, such as microphthalmia, depends on the embryonic stage and concentration of alcohol exposure, as does diminution of retinal Pax6a or forebrain and hindbrain GAD1 gene expression. We also show that changes in eye and brain morphology correlate with changes in Pax6a and GAD1 gene expression. Our results therefore show that transient binge-like ethanol exposures in zebrafish embryos produce the stereotypical morphological phenotypes of FAS, with the severity of phenotypes depending on the developmental stage and alcohol concentration of exposure. PMID:24929233

BEHAVIORAL AND NEUROCHEMICAL CONSEQUENCES OF DEVELOPMENTAL ORGANOTIN EXPOSURE IN RATS.

EPA Science Inventory

Behavioral and Neurochemical Consequences of Developmental Organotin Exposure in Rats.
Ehman, K.,1 Jenkins, S.,2 Barone Jr., S.2 and Moser, V.2 1Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC, 2Neurotoxicology Division, U.S. Environmental Protection ...

DEVELOPMENTAL CONSEQUENCES OF EXPOSURE TO DISINFECTION BY-PRODUCTS IN ANIMAL MODELS

EPA Science Inventory

Developmental consequences of exposure to disinfection by-products in animal models
Sid Hunter, Michael Narotsky, James Andrews
Reproductive Toxicology Division, NHEERL, ORD, US EPA, RTP, NC, 27711

Disinfection by-products (DBPs) are formed by the reaction of disinf...

Developmental cigarette smoke exposure II: Hepatic proteome profiles in 6 month old adult offspring.

PubMed

Neal, Rachel E; Chen, Jing; Webb, Cindy; Stocke, Kendall; Gambrell, Caitlin; Greene, Robert M; Pisano, M Michele

2016-10-01

Utilizing a mouse model of 'active' developmental cigarette smoke exposure (CSE) [gestational day (GD) 1 through postnatal day (PD) 21] characterized by offspring low birth weight, the impact of developmental CSE on liver proteome profiles of adult offspring at 6 months of age was determined. Liver tissue was collected from Sham- and CSE-offspring for 2D-SDS-PAGE based proteome analysis with Partial Least Squares-Discriminant Analysis (PLS-DA). A similar study conducted at the cessation of exposure to cigarette smoke documented decreased gluconeogenesis coupled to oxidative stress in weanling offspring. In the current study, exposure throughout development to cigarette smoke resulted in impaired hepatic carbohydrate metabolism, decreased serum glucose levels, and increased gluconeogenic regulatory enzyme abundances during the fed-state coupled to decreased expression of SIRT1 as well as increased PEPCK and PGC1α expression. Together these findings indicate inappropriately timed gluconeogenesis that may reflect impaired insulin signaling in mature offspring exposed to 'active' developmental CSE. Copyright © 2016 Elsevier Inc. All rights reserved.

Nicotine-induced plasticity during development: modulation of the cholinergic system and long-term consequences for circuits involved in attention and sensory processing.

PubMed

Heath, Christopher J; Picciotto, Marina R

2009-01-01

Despite a great deal of progress, more than 10% of pregnant women in the USA smoke. Epidemiological studies have demonstrated correlations between developmental tobacco smoke exposure and sensory processing deficits, as well as a number of neuropsychiatric conditions, including attention deficit hyperactivity disorder. Significantly, data from animal models of developmental nicotine exposure have suggested that the nicotine in tobacco contributes significantly to the effects of developmental smoke exposure. Consequently, we hypothesize that nicotinic acetylcholine receptors (nAChRs) are important for setting and refining the strength of corticothalamic-thalamocortical loops during critical periods of development and that disruption of this process by developmental nicotine exposure can result in long-lasting dysregulation of sensory processing. The ability of nAChR activation to modulate synaptic plasticity is likely to underlie the effects of both endogenous cholinergic signaling and pharmacologically administered nicotine to alter cellular, physiological and behavioral processes during critical periods of development.

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.

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

PubMed

Misenheimer, John; Nelson, Clay; Huertas, Evelyn; Medina-Vera, Myriam; Prevatte, Alex; Bradham, Karen

2018-01-01

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 region. This study examined total and bioaccessible soil As and Pb concentrations and accumulation in 10 commonly grown garden plants collected from three urban community gardens in Puerto Rico. Bioavailability values were predicted using bioaccessibility data to compare site-specific bioavailability estimates to commonly used default exposure assumptions. Total and bioaccessible As levels in study soils ranged from 2 to 55 mg/kg and 1 to 18 mg/kg, respectively. Total and bioaccessible Pb levels ranged from 19 to 172 mg/kg and 17 to 97 mg/kg, respectively. Measured bioaccessibility values corresponded to 19 to 42% bioaccessible As and 61 to 100% bioaccessible Pb when expressed as a percent of total As and Pb respectively. Predicted relative percent bioavailability of soil As and Pb based on measured bioaccessibility values ranged from 18 to 36% and 51 to 85% for As and Pb respectively. Transfer factors (TFs) measuring uptake of As in plants from soil ranged from 0 to 0.073 in the edible flesh (fruit or vegetable) of plant tissues analyzed and 0.073 to 0.444 in edible leaves. Pb TFs ranged from 0.002 to 0.012 in flesh and 0.023 to 0.204 in leaves. Consistent with TF values, leaves accumulated higher concentrations of As and Pb than the flesh, with the highest tissue concentrations observed in the culantro leaf (3.2 mg/kg dw of As and 8.9 mg/kg dw of Pb). Leaves showed a general but not statistically-significant (α = 0.05) trend of increased As and Pb concentration with increased soil levels, while no trend was observed for flesh tissues. These findings provide critical data that can improve accuracy and reduce uncertainty when conducting site-specific risk determination of potential As and Pb exposure while gardening or consuming garden produce in the understudied region of Puerto Rico.

Exposure to lead by the oral and the pulmonary routes of children living in the vicinity of a primary lead smelter

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

Roels, H.A.; Buchet, J.P.; Lauwerys, R.R.

1980-06-01

A medical survey was carried out among 11-year-old children attending schools situated less than 1 and 2.5 km from a lead smelter. Age-matched control children from a rural and urban area were examined at the same time. The blood lead levels (PbB) of the children living in the smelter area (mainly those attending schools located less than 1 km from the smelter) were higher than those of rural and urban children. The mean PbB levels were usually lower in girls than in boys, especially in the smelter area. Despite a slightly decreasing trend in the annual mean airborne lead concentrationmore » at less than 1 km (mean PbA: from 3.8 ..mu..g/m/sup 3/ in 1974 to 2.3 ..mu..g/m/sup 3/ in 1978) the PbB levels there did not improve, whereas 2.5 km from the plant a significant tendency to normalization of PbB became apparent. Therefore, in the third survey, the medical examination was combined with an environmental study which demonstrated that lead in school-playground dust and in air strongly correlated. Lead on the children's hands (PbH) was also significantly related to lead in air or lead in dust. Less than 1 km from the factory boys and girls had on the average 436 and 244 ..mu..g Pb/hand, respectively, vs 17.0 and 11.4 ..mu..g Pb/hand for rural boys and girls, respectively. Partial correlations between PbB, PbA, and PbH indicated that in the smelter area the quantitative contribution of PbA to the children's PbB is negligible compared to that of PbH. Thus, the control of airborne lead around the lead smelter is not sufficient to prevent excessive exposure of children to environmental lead. In view of the importance of lead transfer from dust and dirt via hands to the gastrointestinal tract remedial actions should be directed simultaneously against the atmospheric emission of lead by the smelter and against the lead particulates deposited on soil, dust, and dirt.« less

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.

Chronic lead exposure reduces doublecortin-expressing immature neurons in young adult guinea pig cerebral cortex.

PubMed

Huang, JuFang; Huang, Kai; Shang, Lei; Wang, Hui; Zhang, Mengqi; Fan, Chun-Ling; Chen, Dan; Yan, Xiaoxin; Xiong, Kun

2012-07-19

Chronic lead (Pb) poisoning remains an environmental risk especially for the pediatric population, and it may affect brain development. Immature neurons expressing doublecortin (DCX+) exist around cortical layer II in various mammals, including adult guinea pigs and humans. Using young adult guinea pigs as an experimental model, the present study explored if chronic Pb exposure affects cortical DCX + immature neurons and those around the subventricular and subgranular zones (SVZ, SGZ). Two month-old guinea pigs were treated with 0.2% lead acetate in drinking water for 2, 4 and 6 months. Blood Pb levels in these animals reached 10.27 ± 0.62, 16.25 ± 0.78 and 19.03 ± 0.86 μg/dL at the above time points, respectively, relative to ~3 μg/dL in vehicle controls. The density of DCX + neurons was significantly reduced around cortical layer II, SVZ and SGZ in Pb-treated animals surviving 4 and 6 months relative to controls. Bromodeoxyuridine (BrdU) pulse-chasing studies failed to find cellular colocalization of this DNA synthesis indicator in DCX + cells around layer II in Pb-treated and control animals. These cortical immature neurons were not found to coexist with active caspase-3 or Fluoro-Jade C labeling. Chronic Pb exposure can lead to significant reduction in the number of the immature neurons around cortical layer II and in the conventional neurogenic sites in young adult guinea pigs. No direct evidence could be identified to link the reduced cortical DCX expression with alteration in local neurogenesis or neuronal death.

Growth and Lead Accumulation Capacity of Lemna minor and Spirodela polyrhiza (Lemnaceae): Interactions with Nutrient Enrichment

PubMed Central

Aksoy, Ahmet

2010-01-01

A study to understand the biological effects of samples prepared with lead and the effects of lead were conducted on Lemna minor L. and Spirodela polyrhiza (L.) Schleid. This study was intended to test the hypothesis that nutrient enrichment (P, NO3−–N and SO42−) enhances the metal tolerance of floating macrophytes. The plants were exposed to Pb concentrations 0, 1, 5, 10, 25, and 50 mg l−1 for a period of 1, 3, 5, and 7 days. L. minor accumulated 561 mg g−1 dry weight (dw) Pb, and S. polyrhiza accumulated 330 mg g−1 dw Pb after 7 days, whereas in the groups enriched with nutrients, L. minor accumulated 128.7 mg g−1 Pb and S. polyrhiza accumulated 68.7 mg g−1 dw Pb after 7 days. Relative growth rates and photosynthetic pigments (chlorophyll a, b, and carotenoid) were measured in L. minor and S. polyrhiza exposed to different Pb concentrations under laboratory conditions. Relative growth rates were negatively correlated with metal exposure, but nutrient addition was found to suppress this effect. Photosynthetic pigment levels were found negatively correlated with metal exposure, and nutrient addition attenuated chlorophyll decrease in response to metal exposure. Metal and nutrient concentration in water decreased throughout the experiments. The study concluded that nutrient enrichment increases the tolerance of L. minor and S. polyrhiza to metals, that L. minor and S. polyrhiza are suitable candidates for the phytoremediation of low-level lead pollution, and that L. minor was more effective in extracting lead than was S. polyrhiza. PMID:21258435

Physiological effects of waterborne lead exposure in spiny dogfish (Squalus acanthias).

PubMed

Eyckmans, Marleen; Lardon, Isabelle; Wood, Chris M; De Boeck, Gudrun

2013-01-15

To broaden our knowledge about the toxicity of metals in marine elasmobranchs, cannulated spiny dogfish (Squalus acanthias) were exposed to 20 μM and 100 μM lead (Pb). Since we wanted to focus on sub lethal ion-osmoregulatory and respiratory disturbances, arterial blood samples were analysed for pH(a), PaO(2), haematocrit and total CO(2) values at several time points. Plasma was used to determine urea, TMAO, lactate and ion concentrations. After 96 h, Pb concentrations were determined in a number of tissues, such as gill, rectal gland, skin and liver. To further investigate ion and osmoregulation, Na(+)/K(+)-ATPase activities in gill and rectal gland were analysed as well as rates of ammonia and urea excretion. Additionally, we studied the energy reserves in muscle and liver. Pb strongly accumulated in gills and especially in skin. Lower accumulation rates occurred in gut, kidney and rectal gland. A clear disturbance in acid-base status was observed after one day of exposure indicating a transient period of hyperventilation. The increase in pH(a) was temporary at 20 μM, but persisted at 100 μM. After 2 days, plasma Na and Cl concentrations were reduced compared to controls at 100 μM Pb and urea excretion rates were elevated. Pb caused impaired Na(+)/K(+)-ATPase activity in gills, but not in rectal gland. We conclude that spiny dogfish experienced relatively low ion-osmoregulatory and respiratory distress when exposed to lead, particularly when compared to effects of other metals such as silver. These elasmobranchs appear to be able to minimize the disturbance and maintain physiological homeostasis during an acute Pb exposure. Copyright © 2012 Elsevier B.V. All rights reserved.

Use of a Cumulative Exposure Index to Estimate the Impact of Tap Water Lead Concentration on Blood Lead Levels in 1- to 5-Year-Old Children (Montréal, Canada)

PubMed Central

Ngueta, Gerard; Abdous, Belkacem; Tardif, Robert; St-Laurent, Julie; Levallois, Patrick

2015-01-01

Background Drinking water is recognized as a source of lead (Pb) exposure. However, questions remain about the impact of chronic exposure to lead-contaminated water on internal dose. Objective Our goal was to estimate the relation between a cumulative water Pb exposure index (CWLEI) and blood Pb levels (BPb) in children 1–5 years of ages. Methods Between 10 September 2009 and 27 March 2010, individual characteristics and water consumption data were obtained from 298 children. Venous blood samples were collected (one per child) and a total of five 1-L samples of water per home were drawn from the kitchen tap. A second round of water collection was performed between 22 June 2011 and 6 September 2011 on a subsample of houses. Pb analyses used inductively coupled plasma mass spectroscopy. Multiple linear regressions were used to estimate the association between CWLEI and BPb. Results Each 1-unit increase in CWLEI multiplies the expected value of BPb by 1.10 (95% CI: 1.06, 1.15) after adjustment for confounders. Mean BPb was significantly higher in children in the upper third and fourth quartiles of CWLEI (0.7–1.9 and ≥ 1.9 μg/kg of body weight) compared with the first (< 0.2 μg/kg) after adjusting for confounders (19%; 95% CI: 0, 42% and 39%; 95% CI: 15, 67%, respectively). The trends analysis yielded a p-value < 0.0001 after adjusting for confounders suggesting a dose–response relationship between percentiles of CWLEI and BPb. Conclusions In children 1–5 years of age, BPb was significantly associated with water lead concentration with an increase starting at a cumulative lead exposure of ≥ 0.7 μg Pb/kg of body weight. In this age group, an increase of 1 μg/L in water lead would result in an increase of 35% of BPb after 150 days of exposure. Citation Ngueta G, Abdous B, Tardif R, St-Laurent J, Levallois P. 2016. Use of a cumulative exposure index to estimate the impact of tap water lead concentration on blood lead levels in 1- to 5-year-old children (Montreal, Canada). Environ Health Perspect 124:388–395; http://dx.doi.org/10.1289/ehp.1409144 PMID:26080391

Sub-lethal and lethal toxicities of elevated CO2 on embryonic, juvenile, and adult stages of marine medaka Oryzias melastigma.

PubMed

Lee, Changkeun; Kwon, Bong-Oh; Hong, Seongjin; Noh, Junsung; Lee, Junghyun; Ryu, Jongseong; Kang, Seong-Gil; Khim, Jong Seong

2018-06-06

The potential leakage from marine CO 2 storage sites is of increasing concern, but few studies have evaluated the probable adverse effects on marine organisms. Fish, one of the top predators in marine environments, should be an essential representative species used for water column toxicity testing in response to waterborne CO 2 exposure. In the present study, we conducted fish life cycle toxicity tests to fully elucidate CO 2 toxicity mechanism effects. We tested sub-lethal and lethal toxicities of elevated CO 2 concentrations on marine medaka (Oryzias melastigma) at different developmental stages. At each developmental stage, the test species was exposed to varying concentrations of gaseous CO 2 (control air, 5%, 10%, 20%, and 30%), with 96 h of exposure at 0-4 d (early stage), 4-8 d (middle stage), and 8-12 d (late stage). Sub-lethal and lethal effects, including early developmental delays, cardiac edema, tail abnormalities, abnormal pigmentation, and mortality were monitored daily during the 14 d exposure period. At the embryonic stage, significant sub-lethal and lethal effects were observed at pH < 6.30. Hypercapnia can cause long-term and/or delayed developmental embryonic problems, even after transfer back to clean seawater. At fish juvenile and adult stages, significant mortality was observed at pH < 5.70, indicating elevated CO 2 exposure might cause various adverse effects, even during short-term exposure periods. It should be noted the early embryonic stage was found more sensitive to CO 2 exposure than other developmental stages of the fish life cycle. Overall, the present study provided baseline information for potential adverse effects of high CO 2 concentration exposure on fish developmental processes at different life cycle stages in marine ecosystems. Copyright © 2018 Elsevier Ltd. All rights reserved.

DEVELOPMENTAL ATRAZINE EXPOSURE SUPPRESSES IMMUNE FUNCTION IN MALE, BUT NOT FEMALE SPRAGUE-DAWLEY RATS

EPA Science Inventory

Developmental Atrazine Exposure Suppresses Immune Function in Male, but not Female Sprague-Dawley Rats

Andrew A. Rooney,*,1 Raymond A. Matulka,? and Robert Luebke?

*College of Veterinary Medicine, Anatomy, Physiological Sciences and Radiology, NCSU, Raleigh, North...

Developmental exposure to perchlorate alters synaptic transmission in hippocampus of the adult rat: in vivo studies.

EPA Science Inventory

Perchlorate, a contaminant found in food and water supplies throughout the USA, blocks iodine uptake into the thyroid gland to reduce circulating levels of thyroid hormone. Neurological function accompanying developmental exposure to perchlorate was evaluated in the present study...

CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS.

EPA Science Inventory

CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS. ME Gilbert1, ME Kelly2, S. Salant3, T Shafer1, J Goodman3 1Neurotoxicology Div, US EPA, RTP, NC, 27711, 2Children's Hospital, Philadelphia, PA, 19104, 3Helen Hayes Hospital, Haverstraw, NY, 10993.
...

PERSPECTIVES ON THE CONCERN FOR AND MANAGEMENT OF PRENATAL CHEMICAL EXPOSURE AND POSTNATAL EFFECTS

EPA Science Inventory

This paper was presented as the introduction to a session on the history and epidemiology of prenatal chemical exposure. lthough teratology and developmental toxicology had its experimental beginnings in the early part of this century, the potential for human developmental toxici...

Early genotoxic response and accumulation induced by waterborne copper, lead, and arsenic in European seabass, Dicentrarchus labrax.

PubMed

Canalejo, Antonio; Diaz-de-Alba, Margarita; Granado-Castro, M Dolores; Cordoba, Francisco; Espada-Bellido, Estrella; Galindo-Riaño, M Dolores; Torronteras, Rafael

2016-02-01

Cu, Pb, and As, which are among the most abundant metals in the aquatic environment, are also among the most health-threatened by causing diverse cellular injuries. The aim of this study was to assess and compare the potential early induction of genotoxic effects after waterborne Cu, Pb, and As exposure in European seabass, Dicentrarchus labrax, a commercial widely cultured fish, using the micronucleus (MN) assay in peripheral blood erythrocytes. Fish were exposed under laboratory conditions to nominal solutions ranging 0-10 mg/L for 24 and 96 h. Furthermore, actual metal ion concentrations were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or differential pulse anodic stripping voltammetry (DPASV) in water and four fish tissues differentially related to environmental exposition and metal accumulation, i.e. the gills, liver, muscle, and brain. Dose-dependent increases of micronuclei (MNi) frequency were observed after these very short exposures; based on measured metal concentrations in water, the genotoxic effect ordered as Cu > As > Pb. Significant genotoxic effect at 0.009 mg/L Cu, 0.57 mg/L Pb, and 0.01 mg/L As was seen. For Cu and Pb these are only slightly higher, but for As it is notably lower than the USEPA criteria of maximum concentration to prevent acute toxicity in aquatic organisms. Furthermore, genotoxicity was differentially related to metal accumulation. MNi frequency correlated positively with the content of Pb in all the organs, with the content of As in liver and gills and only with the content of Cu in the brain. In conclusion, our findings raised environmental concerns because these depicted a genotoxic potential of Cu, Pb, and As after a very short exposure to low but environmentally relevant concentrations, too close to regulatory thresholds. In addition, the MN test in D. labrax could be considered an early biomarker of genotoxicity induced by these metals in fish.

Prevalence and associated demographic characteristics of exposure to multiple metals and their species in human populations: The United States NHANES, 2007-2012.

PubMed

Shim, Youn K; Lewin, Michael D; Ruiz, Patricia; Eichner, June E; Mumtaz, Moiz M

2017-01-01

Lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) are among the top 10 pollutants of global health concern. Studies have shown that exposures to these metals produce severe adverse effects. However, the mechanisms underlying these effects, particularly joint toxicities, are poorly understood in humans. The objective of this investigation was to identify and characterize prevalent combinations of these metals and their species in the U.S. NHANES population to provide background data for future studies of potential metal interactions. Exposure was defined as urine or blood levels ≥ medians of the NHANES 2007-2012 participants ≥6 years (n = 7408). Adjusted-odds ratios (adj-OR) and 95% confidence intervals were determined for covariates (age, gender, and race/ethnicity, cotinine and body mass index). Species-specific analysis was also conducted for As and Hg including iAs (urinary arsenous acid and/or arsenic acid), met-iAs (urinary monomethylarsonic acid and/or dimethylarsinic acid), and oHg (blood methyl-mercury and/or ethyl-mercury). For combinations of As and Hg species, age- and gender-specific prevalence was determined among NHANES 2011-2012 participants (n = 2342). Data showed that approximately 49.3% of the population contained a combination of three or more metals. The most prevalent unique specific combinations were Pb/Cd/Hg/As, Pb/Cd/Hg, and Pb/Cd. Age was consistently associated with these combinations: adj-ORs ranged from 10.9 (Pb/Cd) to 11.2 (Pb/Cd/Hg/As). Race/ethnicity was significant for Pb/Cd/Hg/As. Among women of reproductive age, frequency of oHg/iAs/met-iAS and oHg/met-iAs was 22.9 and 40.3%, respectively. These findings may help prioritize efforts to assess joint toxicities and their impact on public health.

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

Shirayama, Masaki; Kato, Masato; Fujiseki, Takemasa

Low stability of organic-inorganic perovskite (CH{sub 3}NH{sub 3}PbI{sub 3}) solar cells in humid air environments is a serious drawback which could limit practical application of this material severely. In this study, from real-time spectroscopic ellipsometry characterization, the degradation mechanism of ultra-smooth CH{sub 3}NH{sub 3}PbI{sub 3} layers prepared by a laser evaporation technique is studied. We present evidence that the CH{sub 3}NH{sub 3}PbI{sub 3} degradation in humid air proceeds by two competing reactions of (i) the PbI{sub 2} formation by the desorption of CH{sub 3}NH{sub 3}I species and (ii) the generation of a CH{sub 3}NH{sub 3}PbI{sub 3} hydrate phase by H{submore » 2}O incorporation. In particular, rapid phase change occurs in the near-surface region and the CH{sub 3}NH{sub 3}PbI{sub 3} layer thickness reduces rapidly in the initial 1 h air exposure even at a low relative humidity of 40%. After the prolonged air exposure, the CH{sub 3}NH{sub 3}PbI{sub 3} layer is converted completely to hexagonal platelet PbI{sub 2}/hydrate crystals that have a distinct atomic-scale multilayer structure with a period of 0.65 ± 0.05 nm. We find that conventional x-ray diffraction and optical characterization in the visible region, used commonly in earlier works, are quite insensitive to the surface phase change. Based on results obtained in this work, we discuss the degradation mechanism of CH{sub 3}NH{sub 3}PbI{sub 3} in humid air.« less

Chemical nature of the barrier in Pb/YBa2Cu3O(7-x) tunneling structures

NASA Technical Reports Server (NTRS)

Vasquez, R. P.; Foote, M. C.; Hunt, B. D.; Bajuk, L.

1991-01-01

Several reports of reproducible tunneling measurements on YBa2Cu3O(7-x) thin films or single crystals with a Pb counterelectrode have recently appeared. The nature of the tunnel barrier, formed by air exposure, in these structures has been unknown. In the present work, the chemical nature of the tunnel barrier is studied with X-ray photoelectron spectroscopy (XPS). Laser-ablated films grown on LaAlO3 which have been chemically etched and heated in air are found to form nonsuperconducting surface Ba species, evident in an increase of the high binding energy Ba 3d and O 1s signals. A deposited Pb film about 10 A thick is found to be oxidized, and Cu(+2) is partially reduced to Cu(+1). The tunneling barrier thus appears to consist of species resulting from a combination of the air exposure and a reaction between the superconductor and the deposited Pb counterelectrode.

Developmental Toxicity

EPA Science Inventory

This chapter provides an overview the developmental toxicity resulting from exposure to perfluorinated alkyl acids (PFAAs). The majority of studies of PFAA-induced developmental toxicity have examined effects of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA) a...

Alteration of the number and percentage of innate immune cells in preschool children from an e-waste recycling area.

PubMed

Zhang, Yu; Xu, Xijin; Sun, Di; Cao, Junjun; Zhang, Yuling; Huo, Xia

2017-11-01

Heavy metal lead (Pb) and cadmium (Cd) are widespread environmental contaminants and exert detrimental effects on the immune system. We evaluated the association between Pb/Cd exposures and innate immune cells in children from an electronic waste (e-waste) recycling area. A total number of 294 preschool children were recruited, including 153 children from Guiyu (e-waste exposed group), and 141 from Haojiang (reference group). Pb and Cd levels in peripheral blood were measured by graphite furnace atomic absorption spectrophotometer, NK cell percentages were detected by flow cytometer, and other innate immune cells including monocytes, eosinophils, neutrophils and basophils were immediately measured by automated hematology analyzer. Results showed children in Guiyu had significantly higher Pb and Cd levels than in reference group. Absolute counts of monocytes, eosinophils, neutrophils and basophils, as well as percentages of eosinophils and neutrophils were significantly higher in the Guiyu group. In contrast, NK cell percentages were significantly lower in Guiyu group. Pb elicited significant escalation in counts of monocytes, eosinophils and basophils, as well as percentages of monocytes, but decline in percentages of neutrophils in different quintiles with respect to the first quintile of Pb concentrations. Cd induced significant increase in counts and percentages of neutrophils in the highest quintile compared with the first quintile of Cd concentrations. We concluded alteration of the number and percentage of innate immune cells are linked to higher levels of Pb and Cd, which indicates Pb and Cd exposures might affect the innate and adaptive immune response in Guiyu children. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Dietary Selenium Against Lead Toxicity on mRNA Levels of 25 Selenoprotein Genes in the Cartilage Tissue of Broiler Chicken.

PubMed

Gao, H; Liu, C P; Song, S Q; Fu, J

2016-07-01

The interactions between the essential element selenium (Se) and the toxic element lead (Pb) have been reported extensively; however, little is known about the effect of Se on Pb toxicity and the expression pattern of selenoproteins in the cartilage of chicken. To investigate the effects of Se on Pb toxicity and the messenger RNA (mRNA) expressions of selenoproteins in cartilage tissue, an in vitro study was performed on 1-day-old broiler chickens (randomly allocated into four groups) with diet of different concentration of Se and Pb. After 90 days, the meniscus cartilage and sword cartilage tissue were examined for the mRNA levels of 25 selenoprotein genes. The results showed that Se and Pb influenced the expression of selenoprotein genes in the chicken cartilage tissue. In detail, Se could alleviate the downtrend of the expression of Gpx1, Gpx2, Gpx4, Txnrd2, Txnrd3, Dio1, Dio2, Seli, Selu, Sepx1, Selk, Selw, Selo, Selm, Sep15, Sepnn1, Sels, and Selt induced by Pb exposure in the meniscus cartilage. In the sword cartilage, Se alleviated the downtrend of the expression of Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Dio2, Dio3, Seli, Selh, SPS2, Sepx1, Selk, Selw, Selo, Selm, Sep15, Selpb, Sepn1, and Selt induced by Pb exposure. The present study provided some compensated data about the roles of Se against Pb toxicity in the regulation of selenoprotein expression.

The impact of the developmental timing of trauma exposure on PTSD symptoms and psychosocial functioning among older adults.

PubMed

Ogle, Christin M; Rubin, David C; Siegler, Ilene C

2013-11-01

The present study examined the impact of the developmental timing of trauma exposure on posttraumatic stress disorder (PTSD) symptoms and psychosocial functioning in a large sample of community-dwelling older adults (N = 1,995). Specifically, we investigated whether the negative consequences of exposure to traumatic events were greater for traumas experienced during childhood, adolescence, young adulthood, midlife, or older adulthood. Each of these developmental periods is characterized by age-related changes in cognitive and social processes that may influence psychological adjustment following trauma exposure. Results revealed that older adults who experienced their currently most distressing traumatic event during childhood exhibited more severe symptoms of PTSD and lower subjective happiness compared with older adults who experienced their most distressing trauma after the transition to adulthood. Similar findings emerged for measures of social support and coping ability. The differential effects of childhood compared with later life traumas were not fully explained by differences in cumulative trauma exposure or by differences in the objective and subjective characteristics of the events. Our findings demonstrate the enduring nature of traumatic events encountered early in the life course and underscore the importance of examining the developmental context of trauma exposure in investigations of the long-term consequences of traumatic experiences.

Lead exposure in indigenous communities of the Amazon basin, Peru.

PubMed

Anticona, Cynthia; Bergdahl, Ingvar A; Lundh, Thomas; Alegre, Yuri; Sebastian, Miguel San

2011-12-01

Since 2006, three studies have reported elevated levels of lead (Pb) among the indigenous population of the Corrientes river, in the Amazon basin of Peru. Due to the large evidence of environmental pollution related to oil exploitation in the area, this activity has been suggested as the source of exposure. This study aimed to evaluate Pb levels in the population and environment of two communities exposed and one community non-exposed to the oil exploitation activity. Blood lead levels (BLL) were determined by the instrument Leadcare. A comparison with the graphite furnace atomic absorption technique was performed in order to validate the Leadcare results. Environmental samples were analyzed by inductively coupled plasma atomic emission spectroscopy. Among 361 capillary samples, the mean BLL was 9.4 μg/dl. Mean BLL of the communities exposed (n=171, x¯=9.5 μg/dl) and non-exposed (n=190, x¯=9.2 μg/dl) to the oil activity were not significantly different. Pb levels in environmental samples were below the maximum permissible levels. The sources of exposure could not be identified. Elevated levels of Pb in the oil-non-exposed community pointed out at other sources not yet clarified. Copyright © 2011 Elsevier GmbH. All rights reserved.

Germination, Physiological Responses and Gene Expression of Tall Fescue (Festuca arundinacea Schreb.) Growing under Pb and Cd

PubMed Central

Lou, Yanhong; Zhao, Peng; Wang, Deling; Amombo, Erick; Sun, Xin; Wang, Hui; Zhuge, Yuping

2017-01-01

Cadmium (Cd) and lead (Pb) are recognized as the most toxic metal ions due to their detrimental effects not only to plants, but also to humans. The objective of this study was to investigate the effects of Cd and Pb treatments on seed germination, plant growth, and physiological response in tall fescue (Festuca arundinacea Schreb.). We employed six treatments: CK (nutrient solution as control), T1 (1000 mg L-1 Pb), T2 (50 mg L-1 Cd), T3 (150 mg L-1 Cd), T4 (1000 mg L-1 Pb+50 mg L-1 Cd), T5 (1000 mg L-1 Pb+150 mg L-1 Cd). Antagonistic and synergistic actions were observed in tall fescue under Pb and Cd combined treatments. Under low Cd, plants exhibited higher relative germination rate, germ length, VSGR, catalase (CAT) and peroxidase (POD) activities. Additionally, in the shoots, the gene expression level of Cu/Zn SOD, FeSOD, POD, GPX, translocation factors, MDA, EL, and soluble protein contents were reduced under Pb stress. Conversely, under high Cd level, there was a decline in NRT, Pb content in shoots, Pb translocation factors, CAT activity; and an increase in VSGR, Pb content in roots, gene expression level of Cu/ZnSOD and POD in tall fescue exposed to Pb2+ regimes. On the other hand, tall fescue plants treated with low Cd exhibited lower relative germination rate, germination index, germ length, NRT, Cd content in roots. On the other hand there was higher Cd content, Cd translocation factor, CAT and POD activities, and gene expression level of Cu/Zn SOD, FeSOD, POD, GPX under Pb treatment compared with single Cd2+ treatment in the shoots. However, after high Cd exposure, plants displayed lower NRT, Cd content, CAT activity, and exhibited higher Cd contents, Cd translocation factor, MDA content, gene expression level of Cu/ZnSOD and GPX with the presence of Pb2+ relative to single Cd2+ treatment. These findings lead to a conclusion that the presence of low Cd level impacted positively towards tall fescue growth under Pb stress, while high level of Cd impacted negatively. In summary, antioxidant enzymes responded to Cd and Pb interaction at an early stage of exposure, and their gene expression profiles provided more details of the activation of those systems. PMID:28046098

Germination, Physiological Responses and Gene Expression of Tall Fescue (Festuca arundinacea Schreb.) Growing under Pb and Cd.

PubMed

Lou, Yanhong; Zhao, Peng; Wang, Deling; Amombo, Erick; Sun, Xin; Wang, Hui; Zhuge, Yuping

2017-01-01

Cadmium (Cd) and lead (Pb) are recognized as the most toxic metal ions due to their detrimental effects not only to plants, but also to humans. The objective of this study was to investigate the effects of Cd and Pb treatments on seed germination, plant growth, and physiological response in tall fescue (Festuca arundinacea Schreb.). We employed six treatments: CK (nutrient solution as control), T1 (1000 mg L-1 Pb), T2 (50 mg L-1 Cd), T3 (150 mg L-1 Cd), T4 (1000 mg L-1 Pb+50 mg L-1 Cd), T5 (1000 mg L-1 Pb+150 mg L-1 Cd). Antagonistic and synergistic actions were observed in tall fescue under Pb and Cd combined treatments. Under low Cd, plants exhibited higher relative germination rate, germ length, VSGR, catalase (CAT) and peroxidase (POD) activities. Additionally, in the shoots, the gene expression level of Cu/Zn SOD, FeSOD, POD, GPX, translocation factors, MDA, EL, and soluble protein contents were reduced under Pb stress. Conversely, under high Cd level, there was a decline in NRT, Pb content in shoots, Pb translocation factors, CAT activity; and an increase in VSGR, Pb content in roots, gene expression level of Cu/ZnSOD and POD in tall fescue exposed to Pb2+ regimes. On the other hand, tall fescue plants treated with low Cd exhibited lower relative germination rate, germination index, germ length, NRT, Cd content in roots. On the other hand there was higher Cd content, Cd translocation factor, CAT and POD activities, and gene expression level of Cu/Zn SOD, FeSOD, POD, GPX under Pb treatment compared with single Cd2+ treatment in the shoots. However, after high Cd exposure, plants displayed lower NRT, Cd content, CAT activity, and exhibited higher Cd contents, Cd translocation factor, MDA content, gene expression level of Cu/ZnSOD and GPX with the presence of Pb2+ relative to single Cd2+ treatment. These findings lead to a conclusion that the presence of low Cd level impacted positively towards tall fescue growth under Pb stress, while high level of Cd impacted negatively. In summary, antioxidant enzymes responded to Cd and Pb interaction at an early stage of exposure, and their gene expression profiles provided more details of the activation of those systems.

Experimental determination of the oral bioavailability and bioaccessibility of lead particles

PubMed Central

2012-01-01

In vivo estimations of Pb particle bioavailability are costly and variable, because of the nature of animal assays. The most feasible alternative for increasing the number of investigations carried out on Pb particle bioavailability is in vitro testing. This testing method requires calibration using in vivo data on an adapted animal model, so that the results will be valid for childhood exposure assessment. Also, the test results must be reproducible within and between laboratories. The Relative Bioaccessibility Leaching Procedure, which is calibrated with in vivo data on soils, presents the highest degree of validation and simplicity. This method could be applied to Pb particles, including those in paint and dust, and those in drinking water systems, which although relevant, have been poorly investigated up to now for childhood exposure assessment. PMID:23173867

Assessment of semen function and lipid peroxidation among lead exposed men

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

Kasperczyk, Aleksandra; Kasperczyk, Slawomir; Horak, Stanislaw

The study population included healthy, fertile men, employees of Zinc and Lead Metalworks (n = 63). Workers exposed to lead were divided into two groups: a group with moderate exposure to lead (ME) - blood lead level (PbB) 25-40 {mu}g/dl and a group with high exposure to lead (HE) PbB = 40-81 {mu}g/dl. The control group consisted of office workers with no history of occupational exposure to lead. Evaluation of lead, cadmium and zinc level in blood and seminal plasma, zinc protoporphyrin in blood (ZPP), 5-aminolevulinic acid in urine (ALA), malondialdehyde (MDA) in seminal plasma and sperm analysis were performed.more » No differences were noted in the concentration of cadmium and zinc in blood and seminal plasma in the study population. Lipid peroxidation in seminal plasma, represented as MDA concentration, significantly increased by about 56% in the HE group and the percentage of motile sperm cells after 1 h decreased by about 34% in comparison to the control group. No statistically significant correlation between other parameters of sperm analysis and lead exposure parameters nor between lead, cadmium and zinc concentration in blood and seminal plasma were found. A positive association between lead intoxication parameters (PbB, ZPP, lead seminal plasma) and MDA concentration in sperm plasma and inverse correlation with sperm cells motility (PbB, ZPP) was found. An increased concentration of MDA was accompanied by a drop in sperm cells motility. In conclusion, we report that high exposure to lead causes a decrease of sperm motility in men most likely as a result of increased lipid peroxidation, especially if the level in the blood surpasses the concentration of 40 {mu}g/dl.« less

Virtual Tissue Models in Developmental Toxicity Research

EPA Science Inventory

Prenatal exposure to drugs and chemicals may perturb, directly or indirectly, core developmental processes in the embryo (patterning, morphogenesis, proliferation and apoptosis, and cell differentiation), leading to adverse developmental outcomes. Because embryogenesis entails a...

Lead Isotope Characterization of Petroleum Fuels in Taipei, Taiwan

PubMed Central

Yao, Pei-Hsuan; Shyu, Guey-Shin; Chang, Ying-Fang; Chou, Yu-Chen; Shen, Chuan-Chou; Chou, Chi-Su; Chang, Tsun-Kuo

2015-01-01

Leaded gasoline in Taiwan was gradually phased out from 1983 to 2000. However, it is unclear whether unleaded gasoline still contributes to atmospheric lead (Pb) exposure in urban areas. In this study, Pb isotopic compositions of unleaded gasolines, with octane numbers of 92, 95, 98, and diesel from two local suppliers in Taipei were determined by multi-collector inductively coupled plasma mass spectrometry with a two-sigma uncertainty of ± 0.02 %. Lead isotopic ratios of vehicle exhaust (208Pb/207Pb: 2.427, 206Pb/207Pb: 1.148, as estimated from petroleum fuels) overlap with the reported aerosol data. This agreement indicates that local unleaded petroleum fuels, containing 10–45 ng·Pb·g−1, are merely one contributor among various sources to urban aerosol Pb. Additionally, the distinction between the products of the two companies is statistically significant in their individual 208Pb/206Pb ratios (p-value < 0.001, t test). Lead isotopic characterization appears to be applicable as a “fingerprinting” tool for tracing the sources of Pb pollution. PMID:25918913

Exposure to PFOS, PFHxS, or PFHxA, but not GenX, Nafion BP1, or ADONA, Elicits Developmental Neurotoxicity in Larval Zebrafish

EPA Science Inventory

Exposure to polyfluoroalkyl substances (PFAS) like perfluorooctane sulfonic acid (PFOS) or perfluorooctanoic acid (PFOA) are associated with developmental toxicity, neurotoxicity, and carcinogenesis. Legacy PFAS have therefore been replaced with shorter carbon chain and polyfluor...

ALTERATIONS IN BRAIN PROTEIN KINASE C ISOFORMS FOLLOWING DEVELOPMENTAL EXPOSURE TO POLYCHLORINATED BIPHENYL MIXTURE.

EPA Science Inventory

PCBs have been shown to alter several neurochemical end-points and are implicated in the etiology of some neurological diseases. Recent in vivo studies from our laboratory indicated that developmental exposure to a commercial PCB mixture, Aroclor 1254, caused perturbations in cal...

DEVELOPMENTAL EXPOSURE TO A THYROID DISRUPTING CHEMICAL STIMULATES PHAGOCYTOSIS IN JUVENILE SPRAGUE-DAWLEY RATS

EPA Science Inventory

Developmental Exposure to a Thyroid Disrupting Chemical Stimulates Phagocytosis in Juvenile Sprague-Dawley Rats.
AA Rooney1, R Matulka2, and R Luebke3. 1NCSU/US EPA CVM, Department of Anatomy, Physiological Sciences and Radiology, Raleigh, NC;2UNC Department of Toxicology, Cha...

Parental tobacco smoke exposure: Epigenetics and the developmental origins of health and disease

EPA Science Inventory

Epigenetic programming is an important mechanism underlying the Developmental Origins of Health and Disease (DOHaD). Much of the research in this area has focused on maternal nutrition. Parental smoking has emerged as a prime example of how exposure to environmental toxicants dur...

Developmental Exposure to an Environmental PCB Mixture Delays the Propagation of Kindling in the Amygdala

EPA Science Inventory

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to eva...

Developmental Exposure to a Dopaminergic Toxicant Produces Altered Locomotor Activity in Larval Zebrafish

EPA Science Inventory

In an effort to develop a rapid in vivo screen for EPA’s prioritization of toxic chemicals, we are characterizing the locomotor activity of zebrafish (Danio rerio) larvae after developmental exposure to various classes of prototypic drugs that act on the central nervous system. ...

Environmental pollutants and lifestyle factors induce oxidative stress and poor prenatal development.

PubMed

Al-Gubory, Kaïs H

2014-07-01

Developmental toxicity caused by exposure to a mixture of environmental pollutants has become a major health concern. Human-made chemicals, including xenoestrogens, pesticides and heavy metals, as well as unhealthy lifestyle behaviours, mainly tobacco smoking, alcohol consumption and medical drug abuse, are major factors that adversely influence prenatal development and increase susceptibility of offspring to diseases. There is evidence to suggest that the developmental toxicological mechanisms of chemicals and lifestyle factors involve the generation of reactive oxygen species (ROS) and cellular oxidative damage. Overproduction of ROS induces oxidative stress, a state where increased ROS generation overwhelms antioxidant protection and subsequently leads to oxidative damage of cellular macromolecules. Data on the involvement of oxidative stress in the mechanism of developmental toxicity following exposure to environmental pollutants are reviewed in an attempt to provide an updated basis for future studies on the toxic effect of such pollutants, particularly the notion of increased risk for developmental toxicity due to combined and cumulative exposure to various environmental pollutants. The aims of such studies are to better understand the mechanisms by which environmental pollutants adversely affect conceptus development and to elucidate the impact of cumulative exposures to multiple pollutants on post-natal development and health outcomes. Developmental toxicity caused by exposure to mixture of environmental pollutants has become a major health concern. Human-made chemicals, including xenoestrogens, pesticides and heavy metals, as well as unhealthy lifestyle behaviors, mainly tobacco smoking, alcohol consumption and medical drug abuse, are major factors that adversely influence prenatal development and increase the susceptibility of offspring to development complications and diseases. There is evidence to suggest that the developmental toxicological mechanisms of human-made chemicals and unhealthy lifestyle factors involve the generation of reactive oxygen species (ROS) and cellular oxidative damage. Overproduction of ROS induces oxidative stress, a state where increased generation of ROS overwhelms antioxidant protection and subsequently leads to oxidative damage of cellular macromolecules. Exposure to various environmental pollutants induces synergic and cumulative dose-additive adverse effects on prenatal development, pregnancy outcomes and neonate health. Data from the literature on the involvement of oxidative stress in the mechanism of developmental toxicity following in vivo exposure to environmental pollutants will be reviewed in an attempt to provide an updated basis for future studies on the toxic effect of such pollutants, particularly the notion of increased risk for developmental toxicity due to combined and cumulative exposure to various environmental pollutants. The aims of such studies are to better understand the mechanisms by which environmental pollutants adversely affect conceptus development and to elucidate the impact of cumulative exposures to multiple pollutants on postnatal development and health outcomes. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Sensitivity of early life stages of freshwater mussels (Unionidae) to acute and chronic toxicity of lead, cadmium, and zinc in water

USGS Publications Warehouse

Wang, N.; Ingersoll, C.G.; Ivey, C.D.; Hardesty, D.K.; May, T.W.; Augspurger, T.; Roberts, A.D.; Van Genderen, E.; Barnhart, M.C.

2010-01-01

Toxicity of lead, cadmium, or zinc to early life stages of freshwater mussels (fatmucket, Lampsilis siliquoidea; Neosho mucket, L. rafinesqueana) was evaluated in 48-h exposures with mussel larvae (glochidia), in 96-h exposures with newly transformed (5-d-old) and two- or six-month-old juvenile mussels, or in 28-d exposures with two- or four-month-old mussels in reconstituted soft water. The 24-h median effect concentrations (EC50s) for fatmucket glochidia (>299??g Pb/L, >227??g Cd/L, 2,685??g Zn/L) and 96-h EC50s for two- or six-month-old fatmucket (>426??g Pb/L, 199??g Cd/L, 1,700??g Zn/L) were much higher than 96-h EC50s for newly transformed fatmucket (142 and 298??g Pb/L, 16??g Cd/L, 151 and 175??g Zn/L) and Neosho mucket (188??g Pb/L, 20??g Cd/L, 145??g Zn/L). Chronic values for fatmucket were 10??g Pb/L, 6.0??g Cd/L, and 63 and 68??g Zn/L. When mussel data from the present study and the literature were included in updated databases for deriving U.S. Environmental Protection Agency water quality criteria, mussel genus mean acute values were in the lower percentiles of the sensitivity distribution of all freshwater species for Pb (the 26th percentile), Cd (the 15th to 29th percentile), or Zn (the 12th to 21st percentile). The mussel (Lampsilis) genus mean chronic value was the lowest value ever reported for Pb (the 9th percentile) but was near the middle of the sensitivity distribution for Cd (the 61st percentile) or Zn (the 44th percentile). These results indicate that mussels were relatively sensitive to the acute toxicity of these three metals and to the chronic toxicity of Pb, but were moderately sensitive to the chronic toxicity of Cd or Zn compared to other freshwater species. ?? 2010 SETAC.

Sensitivity of early life stages of freshwater mussels (Unionidae) to acute and chronic toxicity of lead, cadmium, and zinc in water.

PubMed

Wang, Ning; Ingersoll, Christopher G; Ivey, Christopher D; Hardesty, Douglas K; May, Thomas W; Augspurger, Tom; Roberts, Andy D; van Genderen, Eric; Barnhart, M Chris

2010-09-01

Toxicity of lead, cadmium, or zinc to early life stages of freshwater mussels (fatmucket, Lampsilis siliquoidea; Neosho mucket, L. rafinesqueana) was evaluated in 48-h exposures with mussel larvae (glochidia), in 96-h exposures with newly transformed (5-d-old) and two- or six-month-old juvenile mussels, or in 28-d exposures with two- or four-month-old mussels in reconstituted soft water. The 24-h median effect concentrations (EC50s) for fatmucket glochidia (>299 microg Pb/L, >227 microg Cd/L, 2,685 microg Zn/L) and 96-h EC50s for two- or six-month-old fatmucket (>426 microg Pb/L, 199 microg Cd/L, 1,700 microg Zn/L) were much higher than 96-h EC50s for newly transformed fatmucket (142 and 298 microg Pb/L, 16 microg Cd/L, 151 and 175 microg Zn/L) and Neosho mucket (188 microg Pb/L, 20 microg Cd/L, 145 microg Zn/L). Chronic values for fatmucket were 10 microg Pb/L, 6.0 microg Cd/L, and 63 and 68 microg Zn/L. When mussel data from the present study and the literature were included in updated databases for deriving U.S. Environmental Protection Agency water quality criteria, mussel genus mean acute values were in the lower percentiles of the sensitivity distribution of all freshwater species for Pb (the 26th percentile), Cd (the 15th to 29th percentile), or Zn (the 12th to 21st percentile). The mussel (Lampsilis) genus mean chronic value was the lowest value ever reported for Pb (the 9th percentile) but was near the middle of the sensitivity distribution for Cd (the 61st percentile) or Zn (the 44th percentile). These results indicate that mussels were relatively sensitive to the acute toxicity of these three metals and to the chronic toxicity of Pb, but were moderately sensitive to the chronic toxicity of Cd or Zn compared to other freshwater species. Copyright 2010 SETAC.

Maternal PUFA status but not prenatal methylmercury exposure is associated with children's language functions at age five years in the Seychelles.

PubMed

Strain, J J; Davidson, Philip W; Thurston, Sally W; Harrington, Donald; Mulhern, Maria S; McAfee, Alison J; van Wijngaarden, Edwin; Shamlaye, Conrad F; Henderson, Juliette; Watson, Gene E; Zareba, Grazyna; Cory-Slechta, Deborah A; Lynch, Miranda; Wallace, Julie M W; McSorley, Emeir M; Bonham, Maxine P; Stokes-Riner, Abbie; Sloane-Reeves, Jean; Janciuras, Joanne; Wong, Rosa; Clarkson, Thomas W; Myers, Gary J

2012-11-01

Evidence from the Seychelles Child Development Nutrition Study suggests that maternal nutritional status can modulate the relationship between prenatal methylmercury (MeHg) exposure and developmental outcomes in children. The aim of this study was to investigate whether maternal PUFA status was a confounding factor in any possible associations between prenatal MeHg exposure and developmental outcomes at 5 y of age in the Republic of Seychelles. Maternal status of (n-3) and (n-6) PUFA were measured in serum collected at 28 wk gestation and delivery. Prenatal MeHg exposure was determined in maternal hair collected at delivery. At 5 y of age, the children completed a comprehensive range of sensitive developmental assessments. Complete data from 225 mothers and their children were available for analysis. Multiple linear regression analyses revealed Preschool Language Scale scores of the children improved with increasing maternal serum DHA [22:6(n-3)] concentrations and decreased with increasing arachidonic acid [20:4(n-6)] concentrations, albeit verbal intelligence improved with increasing (n-6) PUFA concentrations in maternal serum. There were no adverse associations between MeHg exposure and developmental outcomes. These findings suggest that higher fish consumption, resulting in higher maternal (n-3) PUFA status, during pregnancy is associated with beneficial developmental effects rather than detrimental effects resulting from the higher concomitant exposures of the fetus to MeHg. The association of maternal (n-3) PUFA status with improved child language development may partially explain the authors' previous finding of improving language scores, as prenatal MeHg exposure increased in an earlier mother-child cohort in the Seychelles where maternal PUFA status was not measured.

Environmental and dietary exposure of young children to inorganic trace elements.

PubMed

Glorennec, Philippe; Lucas, Jean-Paul; Mercat, Anne-Camille; Roudot, Alain-Claude; Le Bot, Barbara

2016-12-01

Children are exposed to toxic metals and metalloids via their diet and environment. Our objective was to assess the aggregate chronic exposure of children aged 3-6years, living in France, to As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V present in diet, tap water, air, soil and floor dust in the years 2007-2009. Dietary data came from the French Total Diet Study, while concentrations in residential tap water, soil and indoor floor dust came from the 'Plomb-Habitat' nationwide representative survey on children's lead exposure at home. Indoor air concentrations were assumed to be equal to outdoor air concentrations, which were retrieved from regulatory measurements networks. Human exposure factors were retrieved from literature. Data were combined with Monte Carlo simulations. Median exposures were 1.7, 0.3, 10.2, 34.1, 60.3, 0.7, 0.1, 44.3, 1.5 and 95th percentiles were 4.4, 0.5, 15.8, 61.3, 98.3, 2.5, 0.1, 111.1, 2.9μg/kgbw/d for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. Dietary exposures dominate aggregate exposures, with the notable exception of Pb - for which soils and indoor floor dust ingestion contribute most at the 95th percentile. The strengths of this study are that it aggregates exposures that are often estimated separately, and uses a large amount of representative data. This assessment is limited to main diet and residential exposure, and does not take into account the relative bioavailability of compounds. These results could be used to help target prevention strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Medical management of lead-exposed workers: results of physician interviews in New Jersey.

PubMed

Roché, L M; Gerwel, B; Ramaprasad, R; Udasin, I G

1995-02-01

Between July 1990 and April 1992, a questionnaire was administered to the physicians who saw 62 individuals with a blood lead (PbB) level equal to or higher than 2.40 mumol/liter with occupational inorganic lead exposure, to ascertain the medical management of workers with elevated PbB levels. Most of the 62 cases were seen by their personal physician (50%) or a private physician under contract with the company for which the patient worked (40%). Only eight (13%) patients were seen by a physician in a medical specialty assumed to include training relevant to occupational lead exposure. Fifteen percent of the patients' physicians reported taking no action for the elevated PbB level. Twenty-nine percent did not report retesting the patient (all should have been retested). Twenty-one percent of the 62 patients' physicians reported informing no one, including the patient, of the elevated PbB level. The majority of the physicians did not know the answer or declined to answer a question about what PbB level would prompt them to take six follow-up actions. The results of the physician interviews indicate that medical follow-up on workers with elevated PbB levels may not be adequate to prevent lead poisoning of the workers and their co-workers. Recommendations include methods to increase physician and employer knowledge of the medical management of workers with elevated PbB levels and to increase employer compliance with OSHA standards regarding medical surveillance of lead-exposed workers.

Bioaccumulation of Pb2+ and its effects on growth, morphology and pigment contents of Spirulina ( Arthrospira) platensis

NASA Astrophysics Data System (ADS)

Arunakumara, K. K. I. U.; Zhang, Xuecheng; Song, Xiaojin

2008-11-01

A laboratory experiment was conducted to assess the bioaccumulation of Pb2+ and its effects on growth, morphology and pigment contents of Spirulina (Arthrospira) platensis. The specimen cultured in Zarrouk liquid medium was treated with various initial metal concentrations (0, 5, 10, 30, 50 and 100 μg mL-1). The growth of S. platensis was adversely affected by Pb2+ at high concentrations (30, 50 and 100 μg mL-1). However, at low concentrations (5 μg mL-1), Pb2+ could stimulate its growth slightly. The pigment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner. The highest reductions (67% and 53% respectively in chlorophyll α and β carotene) were observed in 100 μg mL-1 treatment group. The LC50 (96 h) of Pb2+ was measured as 75.34 μg mL-1. Apart from a few cases of filament breakages at elevated concentrations (50 and 100 μg mL-1), morphological abnormalities are not specific. Metal bioaccumulation increased with Pb2+ concentrations, but decreased with exposure time. The maximum accumulated amount was 188 mg g-1 dry weight. The bioconcentration factor (BCF) reached to a peak at day 2, followed by a gradual reduction for all the exposure concentrations. S. platensis is able to tolerate considerably high Pb2+ concentrations. Consequently it can be used as a potential species to remove heavy metal from contaminated waters.

Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd-Pb exposures.

PubMed

Xin, Junliang; Huang, Baifei; Yang, Zhongyi; Yuan, Jiangang; Dai, Hongwen; Qiu, Qiu

2010-03-15

A pot experiment was conducted to investigate the stability of Cd and/or Pb accumulation in shoot of Cd and Pb pollution-safe cultivars (PSCs), the hereditary pattern of shoot Cd accumulation, and the transfer potentials of Cd and Pb in water spinach (Ipomoea aquatica Forsk.). A typical Cd-PSC, a typical non-Cd-PSC (Cd accumulative cultivar), a hybrid from the former two cultivars, and two typical Cd+Pb-PSCs were grown in seven soils with different concentrations of Cd and Pb. The results showed that concentrations of Cd and Pb in shoot of the PSCs were always lower than the non-PSC and the highest Cd and Pb transfer factors were also always observed in the non-PSC, indicating the stability of the PSCs in Cd and Pb accumulation. Shoot Cd concentration seemed to be controlled by high Cd dominant gene(s) and thus crossbreeding might not minimize Cd accumulation in water spinach. Interaction between Cd and Pb in soils affected the accumulations of the metals in shoot of water spinach. Under middle Cd and Pb treatments, the presence of higher Pb promoted the accumulation of Cd. However, under high Pb treatment, accumulations of Cd and Pb were both restricted. (c) 2009 Elsevier B.V. All rights reserved.

Characterization of brevetoxin (PbTx-3) exposure in neurons of the anoxia-tolerant freshwater turtle (Trachemys scripta).

PubMed

Cocilova, Courtney C; Milton, Sarah L

2016-11-01

Harmful algal blooms are increasing in frequency and extent worldwide and occur nearly annually off the west coast of Florida where they affect both humans and wildlife. The dinoflagellate Karenia brevis is a key organism in Florida red tides that produces a suite of potent neurotoxins collectively referred to as the brevetoxins (PbTx). Brevetoxins bind to and open voltage gated sodium channels (VGSC), increasing cell permeability in excitable cells and depolarizing nerve and muscle tissue. Exposed animals may thus show muscular and neurological symptoms including head bobbing, muscle twitching, paralysis, and coma; large HABs can result in significant morbidity and mortality of marine life, including fish, birds, marine mammals, and sea turtles. Brevetoxicosis however is difficult to treat in endangered sea turtles as the physiological impacts have not been investigated and the magnitude and duration of brevetoxin exposure are generally unknown. In this study we used the freshwater turtle Trachemys scripta as a model organism to investigate the effects of the specific brevetoxin PbTx-3 in the turtle brain. Primary turtle neuronal cell cultures were exposed to a range of PbTx-3 concentrations to determine excitotoxicity. Agonists and antagonists of voltage-gated sodium channels and downstream targets were utilized to confirm the toxin's mode of action. We found that turtle neurons are highly resistant to PbTx-3; while cell viability decreased in a dose dependent manner across PbTx-3 concentrations of 100-2000nM, the EC 50 was significantly higher than has been reported in mammalian neurons. PbTx-3 exposure resulted in significant Ca 2+ influx, which could be fully abrogated by the VGSC antagonist tetrodotoxin, NMDA receptor blocker MK-801, and tetanus toxin, indicating that the mode of action in turtle neurons is the same as in mammalian cells. As both turtle and mammalian VGSCs have a high affinity for PbTx-3, we suggest that the high resistance of the turtle neuron to PbTx-3 may be related to its ability to withstand anoxic depolarization. The ultimate goal of this work is to design treatment protocols for sea turtles exposed to red tides worldwide. Copyright © 2016 Elsevier B.V. All rights reserved.

Toxic Environmental Chemicals: The Role of Reproductive Health Professionals In Preventing Harmful Exposures

PubMed Central

SUTTON, Patrice; WOODRUFF, Tracey J.; PERRON, Joanne; STOTLAND, Naomi; CONRY, Jeanne A.; MILLER, Mark D.; GIUDICE, Linda C.

2015-01-01

Every pregnant woman in the U.S. is exposed to many and varied environmental chemicals. Rapidly accumulating scientific evidence documents that widespread exposure to environmental chemicals at levels encountered in daily life can adversely impact reproductive and developmental health. Preconception and prenatal exposure to environmental chemicals are of particular import because they may have a profound and lasting impact on health across the life course. Thus, preventing developmental exposures to environmental chemicals would benefit greatly from the active participation of reproductive health professionals in clinical and policy arenas. PMID:22405527

Lead exposure among small-scale battery recyclers, automobile radiator mechanics, and their children in Manila, the Philippines

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

Suplido, M.L.; Ong, C.N.

2000-03-01

Blood lead (PbB) and hemoglobin levels (Hb) were determined in 40 battery repair/recycling shop workers, 16 radiator repair shop workers, and 20 children living in the immediate vicinity of these shops. Unexposed residents with similar socio-economic status were also investigated. Mean PbB level was significantly higher for battery workers when compared to radiator workers and unexposed adults. Among battery workers, 94% had PbB levels above the WHO permissible exposure limit of 40 {micro}g/dL for males and 30 {micro}g/dL for females. There was no demarcation between workplace and living quarters; therefore, workers' families were similarly exposed to hazards. Children living inmore » the immediate vicinity of battery shops also had significantly higher mean PbB levels compared to radiator shop children and unexposed children. For workers with PbB > 40 {micro}g/dL, 90% were anemic. Linear regression showed a correlation between Hb level and log{sub 10}PbB. There was no significant relationship between anemia and blood lead in children. The authors conclude that radiator repair activities appeared to increase the body burden of lead, although not up to a level significantly different from unexposed counterparts. Battery recycling/repair activities, however, significantly increased blood lead levels in workers and their children.« less

Tolerance and hyperaccumulation of a mixture of heavy metals (Cu, Pb, Hg, and Zn) by four aquatic macrophytes.

PubMed

Romero-Hernández, Jorge Alberto; Amaya-Chávez, Araceli; Balderas-Hernández, Patricia; Roa-Morales, Gabriela; González-Rivas, Nelly; Balderas-Plata, Miguel Ángel

2017-03-04

In the present investigation, four macrophytes, namely Typha latifolia (L.), Lemna minor (L.), Eichhornia crassipes (Mart.) Solms-Laubach, and Myriophyllum aquaticum (Vell.) Verdc, were evaluated for their heavy metal (Cu, Pb, Hg, and Zn) hyperaccumulation potential under laboratory conditions. Tolerance analyses were performed for 7 days of exposure at five different treatments of the metals mixture (Cu +2 , Hg +2 , Pb +2 , and Zn +2 ). The production of chlorophyll and carotenoids was determined at the end of each treatment. L. minor revealed to be sensitive, because it did not survive in all the tested concentrations after 72 hours of exposure. E. crassipes and M. aquaticum displayed the highest tolerance to the metals mixture. For the most tolerant species of aquatic macrophytes, The removal kinetics of E. crassipes and M. aquaticum was carried out, using the following mixture of metals: Cu (0.5 mg/L) and Hg, Pb, and Zn 0.25 mg/L. The obtained results revealed that E. crassipes can remove 99.80% of Cu, 97.88% of Pb, 99.53% of Hg, and 94.37% of Zn. M. aquaticum withdraws 95.2% of Cu, 94.28% of Pb, 99.19% of Hg, and 91.91% of Zn. The obtained results suggest that these two species of macrophytes could be used for the phytoremediation of this mixture of heavy metals from the polluted water bodies.

Effects of occupational lead exposure.

PubMed

Wang, Y L; Lu, P K; Chen, Z Q; Liang, Y X; Lu, Q M; Pan, Z Q; Shao, M

1985-01-01

Fifty-three workers in a battery factory, 52 solderers in a television factory, and 50 embroidery workers (a reference group) were studied. The average air lead levels of the three workplaces were 0.578 mg/m3, 0.002 mg/m3, and 0.001 mg/m3, respectively. Adverse effects in terms of clinical manifestations and biochemical criteria were evident among the battery factory workers. A significant dose-response relationship existed between the toxic effects and the air lead levels. The solderers showed no apparent abnormalities in comparison with the embroidery workers. The early clinical manifestations were dysfunction of the central nervous system, indigestion, arthralgia, and myalgia in the extremities. A positive association was observed between the prevalence of fatigue, mild abdominal pain, and arthralgia and the blood lead (PbB), urinary lead (PbU), and zinc protoporphyrin (ZPP) levels. The symptomatic threshold values of PbB, PbU, and ZPP were 30 micrograms/dl (1.5 mumol/l), 0.045 mg/l (0.2 mumol/l), and 40 micrograms/dl (0.7 mumol/l), respectively. The PbB, PbU, free erythrocyte protoporphyrin, and ZPP levels and the blood aminolevulinic dehydratase ratio could be used as indicators of lead exposure, although ZPP is preferred for a preventive monitoring program. The motor and sensory conduction velocities of the median nerve were slower in the exposed groups than in the reference group. No effects on behavioral function were observed among the solderers.

Performance and exposure indices of rats exposed to low concentrations of lead.

PubMed

Cory-Slechta, D A; Weiss, B; Cox, C

1985-04-01

To further characterize the lower end of the function relating lead exposure and biological exposure indices to behavior, male weanling rats were exposed chronically to drinking solutions containing 25 ppm sodium acetate (controls) or 25 ppm lead acetate. Behavioral training began when the animals reached 50 days of age, and performance on a fixed-interval 1-min schedule of food reinforcement was then assessed over 90 experimental sessions (136 days). This exposure produced overall response rate increases over the first 40 sessions that were similar to those observed previously with higher concentrations of lead. Response rates of the two groups tended to merge subsequently. The increased overall response rates in the treated group derived primarily from an increased frequency of shorter interresponse times (IRTs) and increased running rates (calculated without the postreinforcement interval). Blood lead (PbB) and zinc protoporphyrin (ZPP) values were determined following sessions 30, 60, and 90. PbB values of the lead-exposed group averaged 15 to 20 micrograms/dl throughout the study; ZPP did not differ. The mean brain lead value of the treated group was 0.07 micrograms Pb/g. Blood-brain ratios (1.38 to 4.06) were substantially greater than those previously observed at higher exposures. These data extend to even lower exposures, and lower blood lead concentrations, the effective concentration for behavioral effects, and further emphasize the importance of the sensitivity of the endpoint in assessing behavioral toxicity.

Feasibility of a portable X-ray fluorescence device for bone lead measurements of condor bones.

PubMed

Specht, Aaron J; Parish, Chris N; Wallens, Emma K; Watson, Rick T; Nie, Linda H; Weisskopf, Marc G

2018-02-15

Lead based ammunition is a primary source of lead exposure, especially for scavenging wildlife. Lead poisoning remains the leading cause of diagnosed death for the critically endangered California condors, which are annually monitored via blood tests for lead exposure. The results of these tests are helpful in determining recent exposure in condors and in defining the potential for exposure to other species including humans. Since condors are victim to acute and chronic lead exposure, being able to measure both would lend valuable information on the rates of exposure and accumulation through time. A commercial portable X-ray fluorescence (XRF) device has been optimized to measure bone lead in vivo in humans, but this device could also be valuable for field measurements of bone lead in avian species. In this study, we performed measurements of bone Pb in excised, bare condor bones using inductively coupled plasma mass spectrometry (ICP-MS), a cadmium 109 (Cd-109) K-shell X-ray fluorescence (KXRF) system, and a portable XRF system. Both KXRF and portable XRF bone Pb measurement techniques demonstrated good correlations with ICP-MS results (r=0.93 and r=0.92 respectively), even with increasing skin thickness (r=0.86 between ICP-MS and portable XRF at 1.54mm of soft tissue). In conclusion, our results suggest that a portable XRF could be a useful option for measurement of bone Pb in avian species in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of developmental exposure to a Commercial PBDE mixture (DE-71) on protein networks in the rat Cerebellum and Hippocampus

EPA Science Inventory

Title (20 words): Effects of developmental exposure to a Commercial PBDE mixture (DE-71) on protein networks in the rat Cerebellum and Hippocampus. Introduction (120 words): Polybrominated diphenyl ethers (PBDE5) possess neurotoxic effects similar to those of PCBs. The cellular a...

HEALTH EFFECTS OF CHRONIC EXPOSURE TO ARSENIC VIA DRINKING WATER IN INNER MONGOLIA: VI. DEVELOPMENTAL EFFECTS.

EPA Science Inventory

HEALTH EFFECTS OF CHRONIC EXPOSURE TO ARSENIC VIA DRINKING WATER IN INNER MONGOLIA:
VI. DEVELOPMENTAL EFFECTS

Richard K. Kwok, M.S.P.H., Judy L. Mumford, Ph.D., Pauline Mendola, Ph.D. Epidemiology and Biomarkers Branch, NHEERL, US Environmental Protection Agency; Yajua...

Air and blood lead levels in lead acid battery recycling and manufacturing plants in Kenya.

PubMed

Were, Faridah H; Kamau, Geoffrey N; Shiundu, Paul M; Wafula, Godfrey A; Moturi, Charles M

2012-01-01

The concentration of airborne and blood lead (Pb) was assessed in a Pb acid battery recycling plant and in a Pb acid battery manufacturing plant in Kenya. In the recycling plant, full-shift area samples taken across 5 days in several production sections showed a mean value ± standard deviation (SD) of 427 ± 124 μg/m(3), while area samples in the office area had a mean ± SD of 59.2 ± 22.7 μg/m(3). In the battery manufacturing plant, full-shift area samples taken across 5 days in several production areas showed a mean value ± SD of 349 ± 107 μg/m(3), while area samples in the office area had a mean ± SD of 55.2 ± 33.2 μg/m(3). All these mean values exceed the U.S. Occupational Safety and Health Administration's permissible exposure limit of 50 μg/m(3) as an 8-hr time-weighted average. In the battery recycling plant, production workers had a mean blood Pb level ± SD of 62.2 ± 12.7 μg/dL, and office workers had a mean blood Pb level ± SD of 43.4 ± 6.6 μg/dL. In the battery manufacturing plant, production workers had a mean blood Pb level ± SD of 59.5 ± 10.1 μg/dL, and office workers had a mean blood Pb level ± SD of 41.6 ± 7.4 μg/dL. All the measured blood Pb levels exceeded 30 μg/dL, which is the maximum blood Pb level recommended by the ACGIH(®). Observations made in these facilities revealed numerous sources of Pb exposure due to inadequacies in engineering controls, work practices, respirator use, and personal hygiene.

[Inhibition rate of gamma-aminolevulinic acid dehydratase activity in erythrocytes as a reliable index for individual workers of low lead exposure].

PubMed

Hirano, H; Omichi, M; Ohishi, H; Ishikawa, K; Hirashima, N

1983-09-01

As the delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocytes is decreased by lead exposure, we considered that a net reduction of ALAD activity by lead in blood should be the difference between the activity fully activated with zinc (Zn2+) and dithiothreitol (DTT) and that without activation. The optimal condition of activation of ALAD was found by addition of 0.25 mM of Zn2+ and 10 mM of DTT in the reaction mixture. Judging from our previous results that the amount of inhibition of ALAD activity can be represented as the rate of inhibition and is closely correlated with the dose of lead administered to rabbits, the inhibition rate of ALAD activity and lead content in blood (Pb-B) of lead workers were measured. The scatter diagram obtained from the inhibition rate and lead content in blood has two groups being divided at 50 micrograms/ml of Pb-B. In one group less than 50 micrograms/100 ml of Pb-B, the inhibition rate has been closely related to Pb-B., the regression equation being Y = 1.82 X + 11.7, and the correlation coefficient + 0.926. In another group more than 50 micrograms/100 ml of Pb-B the inhibition rate remained constant at the 90% level. Measurement of the inhibition rate suggests to have practical validity for monitoring lead exposure in workers, and by means of a nomograph lead content in blood can be estimated from the inhibition rate.

Assessing the human health risk for aluminium, zinc and lead in outdoor dusts collected in recreational sites used by children at an industrial area in the western part of the Bassin Minier de Provence, France

NASA Astrophysics Data System (ADS)

Reis, A. P.; Patinha, C.; Noack, Y.; Robert, S.; Dias, A. C.; Ferreira da Silva, E.

2014-11-01

The Western part of the “Bassin Minier de Provence”, a former coal mining area, is still occupied by old polluting industries such as a coal-fired power plant and an alumina factory. In 2011 a preliminary outdoor dust survey was carried out in the area as the first step to an exposure and health risk assessment study. Dust samples were taken at 19 sites distributed across the study area, depending on the location of recreational areas used by children to play outdoors. Pseudo-total concentrations of Al, Zn and Pb were determined by ICP-MS and bioaccessible concentrations were estimated using the Unified BARGE Method. Exposure was calculated according to a scenario evaluation approach for dust ingestion and dermal contact routes. Estimation of health risk for exposure to Al, Zn and Pb in outdoor dust was based on the summation of individual risks for the oral and dermal routes. Results show that Al occurs in very high concentrations but mainly innon-bioaccessible forms, especially near the alumina plant. Zinc and Pb occur in low-average levels but mainly in bioaccessible forms. The estimated potential risk decreases according to Pb ≫ Al > Zn and is lower for the ingestion route. The preliminary results presented in this study indicate that, for Al and Zn, the outdoor dusts of the BMP represent an acceptable risk to children's health. However, the estimated hazard quotients suggest that there is some health risk associated to environmental Pb.

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

Hinwood, A.L., E-mail: a.hinwood@ecu.edu.au; Callan, A.C.; Ramalingam, M.

Recent literature suggests that exposure to low concentrations of heavy metals may affect both maternal and child health. This study aimed to determine the biological heavy metals concentrations of pregnant women as well as environmental and dietary factors that may influence exposure concentrations. One hundred and seventy three pregnant women were recruited from Western Australia, each providing a sample of blood, first morning void urine, residential soil, dust and drinking water samples. Participants also completed a questionnaire which included a food frequency component. All biological and environmental samples were analysed for heavy metals using ICP-MS. Biological and environmental concentrations ofmore » lead and mercury were generally low (Median Pb Drinking Water (DW) 0.04 µg/L; Pb soil <3.0 µg/g; Pb dust 16.5 µg/g; Pb blood 3.67 µg/L; Pb urine 0.55; µg/L Hg DW <0.03; Hg soil <1.0 µg/g; Hg dust <1.0 µg/g; Hg blood 0.46 µg/L; Hg urine <0.40 µg/L). Cadmium concentrations were low in environmental samples (Median CdDW 0.02 µg/L; Cdsoil <0.30 ug/g; Cddust <0.30) but elevated in urine samples (Median 0.55 µg/L, creatinine corrected 0.70 µg/g (range <0.2–7.06 µg/g creatinine) compared with other studies of pregnant women. Predictors of increased biological metals concentrations in regression models for blood cadmium were residing in the Great Southern region of Western Australia and not using iron/folic acid supplements and for urinary cadmium was having lower household annual income. However, these factors explained little of the variation in respective biological metals concentrations. The importance of establishing factors that influence low human exposure concentrations is becoming critical in efforts to reduce exposures and hence the potential for adverse health effects. -- Highlights: • Biological heavy metals concentrations in women in their 3rd trimester of pregnancy. • Exposure assessment including environmental, lifestyle and activity data. • Urinary cadmium concentrations were elevated in this group of pregnant women. • Blood lead and mercury concentrations were below recommended biological guideline values.« less

Aerobic capacity of Peruvian Quechua: a test of the developmental adaptation hypothesis.

PubMed

Kiyamu, Melisa; Rivera-Chira, María; Brutsaert, Tom D

2015-03-01

High altitude natives are reported to have outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. To evaluate the developmental effect of lifelong exposure to hypoxia on aerobic capacity, VO2peak was measured on two groups of Peruvian Quechua subjects (18-35 years), who differed in their developmental exposure to altitude. Male and female volunteers were recruited in Lima, Peru (150 m), and were divided in two groups, based on their developmental exposure to hypoxia, those: a) Born at sea-level individuals (BSL), with no developmental exposure to hypoxia (n = 34) and b) Born at high-altitude individuals (BHA) with full developmental exposure to hypoxia (n = 32), but who migrated to sea-level as adults (>16-years-old). Tests were conducted both in normoxia (BP = 750 mm Hg) and normobaric hypoxia at sea-level (BP = 750 mm Hg, FiO2  = 0.12, equivalent to 4,449 m), after a 2-month training period (in order to control for initial differences in physical fitness) at sea-level. BHA had a significantly higher VO2peak at hypoxia (40.31 ± 1.0 ml/min/kg) as compared to BSL (35.78 ± 0.96 ml/min/kg, P = 0.001), adjusting for sex. The decrease of VO2peak at HA relative to SL (ΔVO2peak ) was not different between groups, controlling for baseline levels (VO2peak at sea-level) and sex (BHA = 0.35 ± 0.04 l/min, BSL = 0.44 ± 0.04 l/min; P = 0.12). Forced vital capacity (controlling for height) and the residuals of VO2peak (controlling for weight) had a significant association in the BHA group only (r = 0.155; P = 0.031). In sum, results indicate that developmental exposure to altitude constitutes an important factor to determine superior exercise performance. © 2014 Wiley Periodicals, Inc.

Integrating genetic and toxicogenomic information for determining underlying susceptibility to developmental disorders.

PubMed

Robinson, Joshua F; Port, Jesse A; Yu, Xiaozhong; Faustman, Elaine M

2010-10-01

To understand the complex etiology of developmental disorders, an understanding of both genetic and environmental risk factors is needed. Human and rodent genetic studies have identified a multitude of gene candidates for specific developmental disorders such as neural tube defects (NTDs). With the emergence of toxicogenomic-based assessments, scientists now also have the ability to compare and understand the expression of thousands of genes simultaneously across strain, time, and exposure in developmental models. Using a systems-based approach in which we are able to evaluate information from various parts and levels of the developing organism, we propose a framework for integrating genetic information with toxicogenomic-based studies to better understand gene-environmental interactions critical for developmental disorders. This approach has allowed us to characterize candidate genes in the context of variables critical for determining susceptibility such as strain, time, and exposure. Using a combination of toxicogenomic studies and complementary bioinformatic tools, we characterize NTD candidate genes during normal development by function (gene ontology), linked phenotype (disease outcome), location, and expression (temporally and strain-dependent). In addition, we show how environmental exposures (cadmium, methylmercury) can influence expression of these genes in a strain-dependent manner. Using NTDs as an example of developmental disorder, we show how simple integration of genetic information from previous studies into the standard microarray design can enhance analysis of gene-environment interactions to better define environmental exposure-disease pathways in sensitive and resistant mouse strains. © Wiley-Liss, Inc.

Children's exposure to harmful elements in toys and low-cost jewelry: characterizing risks and developing a comprehensive approach.

PubMed

Guney, Mert; Zagury, Gerald J

2014-04-30

Contamination problem in jewelry and toys and children's exposure possibility have been previously demonstrated. For this study, risk from oral exposure has been characterized for highly contaminated metallic toys and jewelry ((MJ), n=16) considering three scenarios. Total and bioaccessible concentrations of Cd, Cu, Ni, and Pb were high in selected MJ. First scenario (ingestion of parts or pieces) caused unacceptable risk for eight items for Cd, Ni, and/or Pb (hazard index (HI)>1, up to 75, 5.8, and 43, respectively). HI for ingestion of scraped-off material scenario was always <1. Finally, saliva mobilization scenario caused HI>1 in three samples (two for Cd, one for Ni). Risk characterization identified different potentially hazardous items compared to United States, Canadian, and European Union approaches. A comprehensive approach was also developed to deal with complexity and drawbacks caused by various toy/jewelry definitions, test methods, exposure scenarios, and elements considered in different regulatory approaches. It includes bioaccessible limits for eight priority elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Sb). Research is recommended on metals bioaccessibility determination in toys/jewelry, in vitro bioaccessibility test development, estimation of material ingestion rates and frequency, presence of hexavalent Cr and organic Sn, and assessment of prolonged exposure to MJ. Copyright © 2014 Elsevier B.V. All rights reserved.

Developmental fluoxetine exposure increases behavioral despair and alters epigenetic regulation of the hippocampal BDNF gene in adult female offspring.

PubMed

Boulle, Fabien; Pawluski, Jodi L; Homberg, Judith R; Machiels, Barbie; Kroeze, Yvet; Kumar, Neha; Steinbusch, Harry W M; Kenis, Gunter; van den Hove, Daniel L A

2016-04-01

A growing number of infants are exposed to selective serotonin reuptake inhibitor (SSRI) medications during the perinatal period. Perinatal exposure to SSRI medications alter neuroplasticity and increase depressive- and anxiety-related behaviors, particularly in male offspring as little work has been done in female offspring to date. The long-term effects of SSRI on development can also differ with previous exposure to prenatal stress, a model of maternal depression. Because of the limited work done on the role of developmental SSRI exposure on neurobehavioral outcomes in female offspring, the aim of the present study was to investigate how developmental fluoxetine exposure affects anxiety and depression-like behavior, as well as the regulation of hippocampal brain-derived neurotrophic factor (BDNF) signaling in the hippocampus of adult female offspring. To do this female Sprague-Dawley rat offspring were exposed to prenatal stress and fluoxetine via the dam, for a total of four groups of female offspring: 1) No Stress+Vehicle, 2) No Stress+Fluoxetine, 3) Prenatal Stress+Vehicle, and 4) Prenatal Stress+Fluoxetine. Primary results show that, in adult female offspring, developmental SSRI exposure significantly increases behavioral despair measures on the forced swim test, decreases hippocampal BDNF exon IV mRNA levels, and increases levels of the repressive histone 3 lysine 27 tri-methylated mark at the corresponding promoter. There was also a significant negative correlation between hippocampal BDNF exon IV mRNA levels and immobility in the forced swim test. No effects of prenatal stress or developmental fluoxetine exposure were seen on tests of anxiety-like behavior. This research provides important evidence for the long-term programming effects of early-life exposure to SSRIs on female offspring, particularily with regard to affect-related behaviors and their underlying molecular mechanisms. Copyright © 2016 Elsevier Inc. All rights reserved.

Developmental nicotine exposure affects larval brain size and the adult dopaminergic system of Drosophila melanogaster.

PubMed

Morris, Melanie; Shaw, Ariel; Lambert, Madison; Perry, Haley Halperin; Lowenstein, Eve; Valenzuela, David; Velazquez-Ulloa, Norma Andrea

2018-06-14

Pregnant women may be exposed to nicotine if they smoke or use tobacco products, nicotine replacement therapy, or via e-cigarettes. Prenatal nicotine exposure has been shown to have deleterious effects on the nervous system in mammals including changes in brain size and in the dopaminergic system. The genetic and molecular mechanisms for these changes are not well understood. A Drosophila melanogaster model for these effects of nicotine exposure could contribute to faster identification of genes and molecular pathways underlying these effects. The purpose of this study was to determine if developmental nicotine exposure affects the nervous system of Drosophila melanogaster, focusing on changes to brain size and the dopaminergic system at two developmental stages. We reared flies on control or nicotine food from egg to 3rd instar larvae or from egg to adult and determined effectiveness of the nicotine treatment. We used immunohistochemistry to visualize the whole brain and dopaminergic neurons, using tyrosine hydroxylase as the marker. We measured brain area, tyrosine hydroxylase fluorescence, and counted the number of dopaminergic neurons in brain clusters. We detected an increase in larval brain hemisphere area, a decrease in tyrosine hydroxylase fluorescence in adult central brains, and a decrease in the number of neurons in the PPM3 adult dopaminergic cluster. We tested involvement of Dα7, one of the nicotinic acetylcholine receptor subunits, and found it was involved in eclosion, as previously described, but not involved in brain size. We conclude that developmental nicotine exposure in Drosophila melanogaster affects brain size and the dopaminergic system. Prenatal nicotine exposure in mammals has also been shown to have effects on brain size and in the dopaminergic system. This study further establishes Drosophila melanogaster as model organism to study the effects of developmental nicotine exposure. The genetic and molecular tools available for Drosophila research will allow elucidation of the mechanisms underlying the effects of nicotine exposure during development.

Developmental exposure to an environmental PCB mixture delays the propagation of electrical kindling from the amygdala.

PubMed

Bandara, Suren B; Sadowski, Renee N; Schantz, Susan L; Gilbert, Mary E

2017-01-01

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to evaluate the effect of developmental exposure to an environmentally relevant PCB mixture on seizure susceptibility in the rat. Female Long-Evans rats were dosed orally with 0 or 6mg/kg/day of the PCB mixture dissolved in corn oil vehicle 4 weeks prior to mating and continued through gestation and up until postnatal day (PND) 21. On PND 21, pups were weaned, and two males from each litter were randomly selected for the kindling study. As adults, the male rats were implanted bilaterally with electrodes in the basolateral amygdala. For each animal, afterdischarge (AD) thresholds in the amygdala were determined on the first day of testing followed by once daily stimulation at a standard 200μA stimulus intensity until three stage 5 generalized seizures (GS) ensued. Developmental PCB exposure did not affect the AD threshold or total cumulative AD duration, but PCB exposure did increase the latency to behavioral manifestations of seizure propagation. PCB exposed animals required significantly more stimulations to reach stage 2 seizures compared to control animals, indicating attenuated focal (amygdala) excitability. A delay in kindling progression in the amygdala stands in contrast to our previous finding of increased susceptibility to brainstem-mediated audiogenic seizures in PCB-exposed animals in response to a an intense auditory stimulus. These seemingly divergent results are not unexpected given the distinct source, type, and mechanistic underpinnings of these different seizure models. A delay in epileptogenesis following focal amygdala stimulation may reflect a decrease in neuroplasticity following developmental PCB exposure consistent with reductions in use-dependent synaptic plasticity that have been reported in the hippocampus of developmentally PCB exposed animals. Copyright © 2016 Elsevier B.V. All rights reserved.

Clinical Evaluation of Protective Garments with Respect to Garment Characteristics and Manufacturer Label Information.

PubMed

Lichliter, Andrew; Weir, Victor; Heithaus, Robert Evans; Gipson, Sean; Syed, Almas; West, James; Rees, Chet

2017-01-01

To test operator exposures inside radiation protection garments in a simulated clinical setup, examining trends related to multiple characteristics. Sixteen garment models containing lead or nonlead materials and a suspended device (Zero-Gravity) were tested for operator exposure from X rays scattered from an acrylic patient phantom. Weight and surface area were determined. The operator phantom was a wooden frame containing a dosimeter in its cavity. Garments were draped over the frame, and the setup was placed in a typical working position. There was substantial variability in exposures for all garments, ranging from 0.52 to 13.8 µSv/h (mean, 5.39 µSv/h ± 3.82), with a 12-fold difference for garments labeled 0.5 mm Pb equivalent. Most of the especially poor protectors were nonlead, even when not lightweight. Nonlead models were not more protective per weight overall. For closed-back garments labeled 0.5 mm Pb equivalent, mean exposures were lower for lead than for nonlead materials (mean, 1.48 µSv/h ± 0.434 vs 6.26 µSv/h ± 5.13, respectively). Density per exposure -1 was lower for lead than nonlead materials in the 0.5-mm Pb equivalent group, counter to advertised claims. Open-back configurations were lighter than closed (3.3 kg vs 6.0 kg, respectively), with similar mean exposures (5.30 µSv/h vs 5.39 µSv/h, respectively). The lowest exposure was 0.52 µSv/h (9.8% of the mean of all garments) for the suspended device. Operator exposure in a realistic interventional setup is highly variable for similarly labeled protective garments, highlighting the necessity of internal validation when considering nonlead and lightweight models. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

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.

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.

Reproductive disorders associated with pesticide exposure.

PubMed

Frazier, Linda M

2007-01-01

Exposure of men or women to certain pesticides at sufficient doses may increase the risk for sperm abnormalities, decreased fertility, a deficit of male children, spontaneous abortion, birth defects or fetal growth retardation. Pesticides from workplace or environmental exposures enter breast milk. Certain pesticides have been linked to developmental neurobehavioral problems, altered function of immune cells and possibly childhood leukemia. In well-designed epidemiologic studies, adverse reproductive or developmental effects have been associated with mixed pesticide exposure in occupational settings, particularly when personal protective equipment is not used. Every class of pesticides has at least one agent capable of affecting a reproductive or developmental endpoint in laboratory animals or people, including organophosphates, carbamates, pyrethroids, herbicides, fungicides, fumigants and especially organochlorines. Many of the most toxic pesticides have been banned or restricted in developed nations, but high exposures to these agents are still occurring in the most impoverished countries around the globe. Protective clothing, masks and gloves are more difficult to tolerate in hot, humid weather, or may be unavailable or unaffordable. Counseling patients who are concerned about reproductive and developmental effects of pesticides often involves helping them assess their exposure levels, weigh risks and benefits, and adopt practices to reduce or eliminate their absorbed dose. Patients may not realize that by the first prenatal care visit, most disruptions of organogenesis have already occurred. Planning ahead provides the best chance of lowering risk from pesticides and remediating other risk factors before conception.

Sediment exchange to mitigate pollutant exposure in urban soil.

PubMed

Walsh, Daniel; Glass, Katherine; Morris, Samantha; Zhang, Horace; McRae, Isabel; Anderson, Noel; Alfieri, Alysha; Egendorf, Sara Perl; Holberton, Shana; Owrang, Shahandeh; Cheng, Zhongqi

2018-05-15

Urban soil is an ongoing source for lead (Pb) and other pollutant exposure. Sources of clean soil that are locally-available, abundant and inexpensive are needed to place a protective cover layer over degraded urban soil to eliminate direct and indirect pollutant exposures. This study evaluates a novel sediment exchange program recently established in New York City (NYC Clean Soil Bank, CSB) and found that direct exchange of surplus sediment extracted from urban construction projects satisfies these criteria. The CSB has high total yield with 4.2 × 10 5  t of sediment exchanged in five years. Average annual yield (8.5 × 10 4  t yr -1 ) would be sufficient to place a 15-cm (6-in.) sediment cover layer over 3.2 × 10 5  m 2 (80 acres) of impacted urban soil or 1380 community gardens. In a case study of sediment exchange to mitigate community garden soil contamination, Pb content in sediment ranged from 2 to 5 mg kg -1 . This sediment would reduce surface Pb concentrations more than 98% if it was used to encapsulate soil with Pb content exceeding USEPA residential soil standards (400 mg kg -1 ). The maximum observed sediment Pb content is a factor of 42 and 71 lower than median surface soil and garden soil in NYC, respectively. All costs (transportation, chemical testing, etc.) in the CSB are paid by the donor indicating that urban sediment exchange could be an ultra-low-cost source for urban soil mitigation. Urban-scale sediment exchange has advantages over existing national- or provincial-scale sediment exchanges because it can retain and upcycle local sediment resources to attain their highest and best use (e.g. lowering pollutant exposure), achieve circular urban materials metabolism, improve livability and maximize urban sustainability. Published by Elsevier Ltd.

Residential metal contamination and potential health risks of exposure in adobe brick houses in Potosí, Bolivia.

PubMed

McEwen, Abigail R; Hsu-Kim, Heileen; Robins, Nicholas A; Hagan, Nicole A; Halabi, Susan; Barras, Olivo; Richter, Daniel deB; Vandenberg, John J

2016-08-15

Potosí, Bolivia, is the site of centuries of historic and present-day mining of the Cerro Rico, a mountain known for its rich polymetallic deposits, and was the site of large-scale Colonial era silver refining operations. In this study, the concentrations of several metal and metalloid elements were quantified in adobe brick, dirt floor, and surface dust samples from 49 houses in Potosí. Median concentrations of total mercury (Hg), lead (Pb), and arsenic (As) were significantly greater than concentrations measured in Sucre, Bolivia, a non-mining town, and exceeded US-based soil screening levels. Adobe brick samples were further analyzed for bioaccessible concentrations of trace elements using a simulated gastric fluid (GF) extraction. Median GF extractable concentrations of Hg, As, and Pb were 0.085, 13.9, and 32.2% of the total element concentration, respectively. Total and GF extractable concentrations of Hg, As, and Pb were used to estimate exposure and potential health risks to children following incidental ingestion of adobe brick particles. Risks were assessed using a range of potential ingestion rates (50-1000mg/day). Overall, the results of the risk assessment show that the majority of households sampled contained concentrations of bioaccessible Pb and As, but not Hg, that represent a potential health risk. Even at the lowest ingestion rate considered, the majority of households exceeded the risk threshold for Pb, indicating that the concentrations of this metal are of particular concern. To our knowledge, this is the first study to quantify key trace elements in building materials in adobe brick houses and the results indicate that these houses are a potential source of exposure to metals and metalloids in South American mining communities. Additional studies are needed to fully characterize personal exposure and to understand potential adverse health outcomes within the community. Copyright © 2016 Elsevier B.V. All rights reserved.

Childhood lead exposure in France: benefit estimation and partial cost-benefit analysis of lead hazard control

PubMed Central

2011-01-01

Background Lead exposure remains a public health concern due to its serious adverse effects, such as cognitive and behavioral impairment: children younger than six years of age being the most vulnerable population. In Europe, the lead-related economic impacts have not been examined in detail. We estimate the annual costs in France due to childhood exposure and, through a cost benefit analysis (CBA), aim to assess the expected social and economic benefits of exposure abatement. Methods Monetary benefits were assessed in terms of avoided national costs. We used results from a 2008 survey on blood-lead (B-Pb) concentrations in French children aged one to six years old. Given the absence of a threshold concentration being established, we performed a sensitivity analysis assuming different hypothetical threshold values for toxicity above 15 μg/L, 24 μg/L and 100 μg/L. Adverse health outcomes of lead exposure were translated into social burden and economic costs based on literature data from literature. Direct health benefits, social benefits and intangible avoided costs were included. Costs of pollutant exposure control were partially estimated in regard to homes lead-based paint decontamination, investments aiming at reducing industrial lead emissions and removal of all lead drinking water pipes. Results The following overall annual benefits for the three hypothetical thresholds values in 2008 are: €22.72 billion, €10.72 billion and €0.44 billion, respectively. Costs from abatement ranged from €0.9 billion to 2.95 billion/year. Finally, from a partial CBA of lead control in soils and dust the estimates of total net benefits were € 3.78 billion, € 1.88 billion and €0.25 billion respectively for the three hypothesized B-Pb effect values. Conclusions Prevention of childhood lead exposure has a high social benefit, due to reduction of B-Pb concentrations to levels below 15 μg/L or 24 μg/L, respectively. Reducing only exposures above 100 μg/L B-Pb has little economic impact due to the small number of children who now exhibit such high exposure levels. Prudent public policies would help avoiding future medical interventions, limit the need for special education and increase future productivity, and hence lifetime income for children exposed to lead. PMID:21599937

Hybrid embryos produced by transferring panda or cat somatic nuclei into rabbit MII oocytes can develop to blastocyst in vitro.

PubMed

Wen, Duan-Cheng; Bi, Chun-Ming; Xu, Ying; Yang, Cai-Xia; Zhu, Zi-Yu; Sun, Qing-Yuan; Chen, Da-Yuan

2005-08-01

The developmental potential of hybrid embryos produced by transferring panda or cat fibroblasts into nucleated rabbit oocytes was assessed. Both the panda-rabbit and the cat-rabbit hybrid embryos were able to form blastocysts in vitro. However, the rates of attaining the two-cell, four-cell, eight-cell, morula, or blastocyst stages for panda-rabbit hybrids were significantly greater than those of cat-rabbit hybrids (P<0.05). Transferring the rabbit fibroblasts into nucleated rabbit oocytes, 31.0% of the blastocyst rate was obtained, which was significantly higher than that of both the panda-rabbit and the cat-rabbit hybrid embryos (P<0.05). Whether or not the second polar body (PB2) was extruded from the one-cell hybrid embryos (both panda-rabbit and cat-rabbit hybrids) significantly affected their developmental capacity. Embryos without an extruded PB2 showed a higher capacity to develop into blastocysts (panda-rabbit: 19.2%; cat-rabbit: 4.3%), while embryos with extruded PB2 could only develop to the morula stage. The hybrid embryos formed pronucleus-like structures (PN) in 2-4 hr after activation, and the number of PN in one-cell embryos varied from one to five. Tracking of the nucleus in the egg after fusion revealed that the somatic nucleus could approach and aggregate with the oocyte nucleus spontaneously. Chromosome analysis of the panda-rabbit blastocysts showed that the karyotype of the hybrid embryos (2n=86) consisted of chromosomes from both the panda (2n=42) and the rabbit (2n=44). The results demonstrate that (1) it is possible to produce genetic hybrid embryos by interspecies nuclear transfer; (2) the developmental potential of the hybrid embryos is highly correlated to the donor nucleus species; and (3) the hybrid genome is able to support the complete preimplantation embryonic development of the hybrids. Copyright (c) 2005 Wiley-Liss, Inc.

Auxin effects on Pb phytoextraction from polluted soils by Tegetes minuta L. and Bidens pilosa L.: Extractive power of their root exudates.

PubMed

Salazar, María Julieta; Rodriguez, Judith Hebelen; Cid, Carolina Vergara; Pignata, María Luisa

2016-07-05

The principal impediment for Pb uptake by plants is the Casparian strip in roots. It prevents metals reaching the xylem, thereby hampering translocation to the aerial organs. In the root apices, young root cells have thin cell walls and the Casparian strip is not completely developed, which could facilitate Pb uptake by roots at these vulnerable points. However, as the phytotoxic effects of Pb reduce root growth and enhance suberization, entry of Pb into the plant is avoided. We propose that the application of root growth promotors could be an important complement in the phytoextraction of Pb from polluted soils, due to their effects on produced biomass, Pb toxicity, and root exudate production. A greenhouse experiment was carried on to evaluate the auxin application effect on the Pb uptake of Bidens pilosa and Tagetes minuta. These species were sensitive to auxins, but the phytotoxic effect of Pb was not reversed by this treatment. Root exudates capable of extracting Pb were produced only when the species were grown in highly polluted soils, indicating a behavioral response to Pb exposure which is desirable for phytoremediation. Copyright © 2016 Elsevier B.V. All rights reserved.

EXPOSURE OF RAINBOW TROUT TO DIETARY METALS USING LIVE PREY

EPA Science Inventory

Dietary exposure to CD, Cu, ZN, and Pb has been shown to cause accumulatioin of metal in fish and other aquatic organisms...In this study the toxicity of dietary metal exposure was evaluated using an experimental food chain of sediment from oligochaetes to fish...Relationships am...

Multiple-metal exposure, diet, and oxidative stress in Uruguayan school children.

PubMed

Kordas, Katarzyna; Roy, Aditi; Vahter, Marie; Ravenscroft, Julia; Mañay, Nelly; Peregalli, Fabiana; Martínez, Gabriela; Queirolo, Elena I

2018-06-26

Oxidative stress (OS) is an important consequence of exposure to toxic metals but it is unclear to what extent low-level metal exposures contribute to OS in children. We examined the cross-sectional association between urinary concentrations of arsenic (As), cadmium (Cd), and lead (Pb) and urinary markers of OS: F 2 -8α isoprostane and 8-hydroxy-2-deoxy-guanosine (8-OHdG). We also tested effect modification by dietary intakes. Of the 211 children aged 6-8 years living in Montevideo who were eligible for the study because they had at least one OS marker measured via ELISA, 143 were included in a complete-case analysis. Urinary metals were measured with inductively coupled plasma mass spectrometry (ICP-MS: Pb, Cd) and high-performance liquid chromatography online with hydride generation ICP-MS (As-metabolites); concentrations were log 2 -transformed. All urinary markers were adjusted for specific gravity of urine. Two 24-h dietary recalls were conducted to estimate children's dietary intakes, including total fruit and vegetable consumption and vitamin C, zinc and fiber intake. Ordinary least square (OLS) and weighted quantile sum (WQS) regressions were used to estimate the association between metals and each OS marker as outcome. Metal exposure was generally low: median urinary As, Cd, Pb 9.6 μg/L, 0.06 μg/L and 1.9 μg/L, respectively. Median 8-isoprostane concentration was 1.1 and 8-OHdG 39.6 ng/mL. Log 2 -transformed urinary As concentrations were positively associated with 8-OHdG concentrations (10.90 [3.82, 17.97]) in covariate-adjusted OLS models which also took account of exposure to Cd and Pb. In WQS, a mixture index was also associated with higher 8-OHdG (8.71 [1.12, 16.3] for each 25% increase in index value), mostly driven by As exposure. There was little evidence of effect modification by dietary antioxidants. In sum, even at low-level, As exposure is associated with detectable oxidative damage to the DNA. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of developmental exposure to bisphenol A and ethinyl estradiol on spatial navigational learning and memory in painted turtles (Chrysemys picta).

PubMed

Manshack, Lindsey K; Conard, Caroline M; Johnson, Sarah A; Alex, Jorden M; Bryan, Sara J; Deem, Sharon L; Holliday, Dawn K; Ellersieck, Mark R; Rosenfeld, Cheryl S

2016-09-01

Developmental exposure of turtles and other reptiles to endocrine disrupting chemicals (EDCs), including bisphenol A (BPA) and ethinyl estradiol (EE2, estrogen present in birth control pills), can induce partial to full gonadal sex-reversal in males. No prior studies have considered whether in ovo exposure to EDCs disrupts normal brain sexual differentiation. Yet, rodent model studies indicate early exposure to these chemicals disturbs sexually selected behavioral traits, including spatial navigational learning and memory. Thus, we sought to determine whether developmental exposure of painted turtles (Chrysemys picta) to BPA and EE2 results in sex-dependent behavioral changes. At developmental stage 17, turtles incubated at 26⁰C (male-inducing temperature) were treated with 1) BPA High (100μg /mL), 2) BPA Low (0.01μg/mL), 3) EE2 (0.2μg/mL), or 4) vehicle or no vehicle control groups. Five months after hatching, turtles were tested with a spatial navigational test that included four food containers, only one of which was baited with food. Each turtle was randomly assigned one container that did not change over the trial period. Each individual was tested for 14 consecutive days. Results show developmental exposure to BPA High and EE2 improved spatial navigational learning and memory, as evidenced by increased number of times spent in the correct target zone and greater likelihood of solving the maze compared to control turtles. This study is the first to show that in addition to overriding temperature sex determination (TSD) of the male gonad, these EDCs may induce sex-dependent behavioral changes in turtles. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of Epidemiology and Animal Data for Risk Assessment: Chlorpyrifos Developmental Neurobehavioral Outcomes

PubMed Central

Li, Abby A.; Lowe, Kimberly A.; McIntosh, Laura J.; Mink, Pamela J.

2012-01-01

Developmental neurobehavioral outcomes attributed to exposure to chlorpyrifos (CPF) obtained from epidemiologic and animal studies published before June 2010 were reviewed for risk assessment purposes. For epidemiological studies, this review considered (1) overall strength of study design, (2) specificity of CPF exposure biomarkers, (3) potential for bias, and (4) Hill guidelines for causal inference. In the case of animal studies, this review focused on evaluating the consistency of outcomes for developmental neurobehavioral endpoints from in vivo mammalian studies that exposed dams and/or offspring to CPF prior to weaning. Developmental neuropharmacologic and neuropathologic outcomes were also evaluated. Experimental design and methods were examined as part of the weight of evidence. There was insufficient evidence that human developmental exposures to CPF produce adverse neurobehavioral effects in infants and children across different cohort studies that may be relevant to CPF exposure. In animals, few behavioral parameters were affected following gestational exposures to 1 mg/kg-d but were not consistently reported by different laboratories. For postnatal exposures, behavioral effects found in more than one study at 1 mg/kg-d were decreased errors on a radial arm maze in female rats and increased errors in males dosed subcutaneously from postnatal day (PND) 1 to 4. A similar finding was seen in rats exposed orally from PND 1 to 21 with incremental dose levels of 1, 2, and 4 mg/kg-d, but not in rats dosed with constant dose level of 1 mg/kg-d. Neurodevelopmental behavioral, pharmacological, and morphologic effects occurred at doses that produced significant brain or red blood cell acetylcholinesterase inhibition in dams or offspring. PMID:22401178

Effects of lead and cadmium co-exposure on hemoglobin in a Chinese population.

PubMed

Chen, Xiao; Zhou, Hao; Li, Xiaoshuang; Wang, Zhongqiu; Zhu, Guoying; Jin, Taiyi

2015-03-01

Cadmium (Cd) and lead (Pb) show adverse effects on hemoglobin. But most studies are focussed on one single agent. In this study, we observed the main and interactive effects of Cd and Pb on the hemoglobin level in a Chinese population. A total of 308 persons (202 women and 106 men), living in controlled and polluted areas, were included in this study. Blood and urine were collected to determine the levels of hemoglobin (Hb), Cd, Pb, and urinary N-acetyl-β-D-glucosaminidase (UNAG). The Cd and Pb level of subjects living in the polluted area were significantly higher compared to those living in the control area (p<0.05). The level of hemoglobin was declined with the increasing BPb (p<0.05) and BCd in women. The Hb of women and men with the highest level of BCd and BPb were decreased by 8.3g/L and 10.7 g/L compared to those with the lowest level of BCd and BPb, respectively. The Hb level of those women and men with the highest level of UNAG decreased by 4.2g/L and 17.2g/L compared with those with low level of UNAG, respectively. Hb was negatively associated with BPb, BCd, and UNAG. This study evidenced that Cd and Pb can influence Hb level. In addition, our study shows that Cd and Pb may have interactive effects on Hb and Hb level was correlated with tubular dysfunction caused by Cd and Pb exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

Antioxidant responses in gills and digestive gland of oyster Crassostrea madrasensis (Preston) under lead exposure.

PubMed

Shenai-Tirodkar, Prachi S; Gauns, Mangesh U; Mujawar, Mohammad Wassim A; Ansari, Zakir A

2017-08-01

Crassostrea are ecologically and economically important bivalves and provide a good livelihood for coastal regions of many countries, including India. This study aims at evaluating the response of the antioxidant defense system in oyster Crassostrea madrasensis against lead (Pb) exposure under laboratory conditions. Antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transferase (GST) and oxidative damage parameter lipid peroxidation (LPO) were measured in the gills and digestive glands of oysters exposed to 1-50µg/l of Pb (NO 3 ) 2 over a period of 8 days. LPO index increased progressively with increase in Pb concentration (1, 10, 25 and 50µg/l) in both tissues, gills and digestive gland. Although CAT and SOD activities induced together in the initial phase (upto 6th day), their activities decreased at a later stage of the experiment. However, GST activity increased on 8th day in both the tissues at concentration 10, 25 and 50µg/l indicates the compensatory defense mechanism against oxidative stress. The induced antioxidant responses recorded at 25 and 50µg/l of Pb concentrations suggest the presence of Pb-induced oxidative stress at these concentrations. The results of this work also indicate that LPO, SOD, and GST could be used as biomarkers to assess the impact of Pb on the C. madrasensis. This study concludes that any high level of dissolved Pb concentration (>10µg/l) in surrounding seawater could be harmful to the physiology of the C. madrasensis. Copyright © 2017 Elsevier Inc. All rights reserved.

A comparative study of the effect of some nutritional medicinal plants effect on lead accumulation in the liver following different modes of administration

PubMed Central

Nwokocha, Chukwuemeka; Younger-Coleman, Novie; Nwokocha, Magdalene; Owu, Daniel; Iwuala, Moses

2014-01-01

Context and Objectives: Lead (Pb) toxicity leads to cell damage in many organs of the body. Using different treatment interventions and modes of administration we comparatively examined the protective ability of some medicinal plants on liver Pb accumulation. Materials and Methods: Rats were fed on either 7% w/w Zingiber officinale, 7% w/w Allium sativum, 10% w/w Lycopersicon esculentum, 5%, w/w Garcinia kola (all in rat chow), while Pb (100 ppm) was given in drinking water. The additives were administered together with (mode 1), a week after exposure to (mode 2) or a week before metal exposure to (mode 3) the metal for a period of 6 weeks. The metal accumulations in the liver were determined using atomic absorption spectrometry and compared using analysis of variance. Results: Some additives significantly (P < 0.05) reduced, while others enhanced Pb accumulation. Mode 2 yielded the highest mean % protection and mode 3 the lowest, no significant interaction between modes of administration and time of measurement in their relationships to percentage protection, but there was statistically significant (P < 0.05) interaction between modes of administration and additive used in their relationships to percentage protection. Conclusion: Protective effects of medicinal plants are varied and depend on the nature of lead exposure. PMID:25276068

Toxic responses of cytochrome P450 sub-enzyme activities to heavy metals exposure in soil and correlation with their bioaccumulation in Eisenia fetida.

PubMed

Cao, Xiufeng; Bi, Ran; Song, Yufang

2017-10-01

The dose- and time- dependent responses of cytochrome P450 (CYP) sub-enzyme activities to heavy metals in soil, and the relationships between biomarker responses and metal bioaccumulation in Eisenia fetida were evaluated. Earthworms were exposed to soils spiked with increasing doses of Cd, Cu, Pb or Zn for 21 d. Results demonstrated that EROD and CYP3A4 activities responded significantly with increasing dose and exposure duration. EROD activity significantly (P < 0.05) correlated with CYP3A4 activity exposed to Pb and Cu. The earthworm metal burdens had significant correlation with the total metal concentrations in soil (P < 0.01). The bioaccumulation factor (BAF) decreased with the increasing metal concentration in soil. The order of metal bioavailability to E. fetida was Cd > Zn > Cu > Pb. CYP3A4 activity in Pb-exposed earthworms had a significant correlation with the accumulated metal (P < 0.05). Both EROD and CYP3A4 activities in Cu-exposed worms negatively correlated with BAF (P < 0.05). Based on Discriminant Analysis (DA), CYPs activities were sensitive biomarkers of heavy metals exposure, and we also concluded that different biomarkers with multiple durations could be conducted in the eco-toxicological diagnosis of soil pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

Chromatin Switches during Neural Cell Differentiation and Their Dysregulation by Prenatal Alcohol Exposure.

PubMed

Gavin, David P; Grayson, Dennis R; Varghese, Sajoy P; Guizzetti, Marina

2017-05-11

Prenatal alcohol exposure causes persistent neuropsychiatric deficits included under the term fetal alcohol spectrum disorders (FASD). Cellular identity emerges from a cascade of intrinsic and extrinsic (involving cell-cell interactions and signaling) processes that are partially initiated and maintained through changes in chromatin structure. Prenatal alcohol exposure influences neuronal and astrocyte development, permanently altering brain connectivity. Prenatal alcohol exposure also alters chromatin structure through histone and DNA modifications. However, the data linking alcohol-induced differentiation changes with developmental alterations in chromatin structure remain to be elucidated. In the first part of this review, we discuss the sequence of chromatin structural changes involved in neural cell differentiation during normal development. We then discuss the effects of prenatal alcohol on developmental histone modifications and DNA methylation in the context of neurogenesis and astrogliogenesis. We attempt to synthesize the developmental literature with the FASD literature, proposing that alcohol-induced changes to chromatin structure account for altered neurogenesis and astrogliogenesis as well as altered neuron and astrocyte differentiation. Together these changes may contribute to the cognitive and behavioral abnormalities in FASD. Future studies using standardized alcohol exposure paradigms at specific developmental stages will advance the understanding of how chromatin structural changes impact neural cell fate and maturation in FASD.

Chromatin Switches during Neural Cell Differentiation and Their Dysregulation by Prenatal Alcohol Exposure

PubMed Central

Gavin, David P.; Grayson, Dennis R.; Varghese, Sajoy P.; Guizzetti, Marina

2017-01-01

Prenatal alcohol exposure causes persistent neuropsychiatric deficits included under the term fetal alcohol spectrum disorders (FASD). Cellular identity emerges from a cascade of intrinsic and extrinsic (involving cell-cell interactions and signaling) processes that are partially initiated and maintained through changes in chromatin structure. Prenatal alcohol exposure influences neuronal and astrocyte development, permanently altering brain connectivity. Prenatal alcohol exposure also alters chromatin structure through histone and DNA modifications. However, the data linking alcohol-induced differentiation changes with developmental alterations in chromatin structure remain to be elucidated. In the first part of this review, we discuss the sequence of chromatin structural changes involved in neural cell differentiation during normal development. We then discuss the effects of prenatal alcohol on developmental histone modifications and DNA methylation in the context of neurogenesis and astrogliogenesis. We attempt to synthesize the developmental literature with the FASD literature, proposing that alcohol-induced changes to chromatin structure account for altered neurogenesis and astrogliogenesis as well as altered neuron and astrocyte differentiation. Together these changes may contribute to the cognitive and behavioral abnormalities in FASD. Future studies using standardized alcohol exposure paradigms at specific developmental stages will advance the understanding of how chromatin structural changes impact neural cell fate and maturation in FASD. PMID:28492482

Developmental effects of 3,4-methylenedioxymethamphetamine: a review.

PubMed

Skelton, Matthew R; Williams, Michael T; Vorhees, Charles V

2008-03-01

+/-3,4-Methylenedioxymethamphetamine (MDMA) is a chemical derivative of amphetamine that has become a popular drug of abuse and has been shown to deplete serotonin in the brains of users and animals exposed to it. To date, most studies have investigated the effects of MDMA on adult animals. With a majority of users of MDMA being young adults, the chances of the users becoming pregnant and exposing the fetuses to MDMA are also a concern. Evidence to date has shown that developmental exposure to MDMA results in learning and memory impairments in the Morris water maze, a task known to be sensitive to hippocampal disruption, when the animals are tested as adults. Developmental MDMA exposure leads to hypoactivity in the offspring as adults but does not affect outcome on tests of anxiety. MDMA administration decreases pup weight, increases corticosterone and brain-derived neurotrophic factor levels during treatment while decreasing brain levels of serotonin; a decrease that initially dissipates and then reappears in adulthood. Neonatal MDMA exposure increases the sensitivity of the serotonin 1A receptor, a possible mechanism underlying the learning and memory deficits seen. Taken together, the evidence shows that MDMA exposure has adverse effects on the developing brain and behavior. The animal and human data on developmental MDMA exposure are reviewed and their public health implications discussed.

Lasting Effects on Body Weight and Mammary Gland Gene Expression in Female Mice upon Early Life Exposure to n-3 but Not n-6 High-Fat Diets

EPA Science Inventory

Exposure to an imbalance of nutrients prior to conception and during critical developmental periods can have lasting consequences on physiological processes resulting in chronic diseases later in life. Developmental programming has been shown to involve structural and functional ...

The Positive Impact of Early Intervention for Children with Developmental Delays, Gestational Cocaine Exposure, and Co-Occurring Risk Factors

ERIC Educational Resources Information Center

Ullery, Mary Anne; Katz, Lynne

2017-01-01

This article examined transition rates of young children (n = 102) from an early intervention program at the Linda Ray Intervention Program (LRIP) who had documented developmental delays and co-occurring prenatal drug exposure often coupled with verified child maltreatment. Findings indicated that there was significant group improvement from…

LONG-LASTING NEUROSTRUCTURAL CONSEQUENCES IN THE RAT HIPPOCAMPUS BY DEVELOPMENTAL EXPOSURE TO A MIXTURE OF POLYCHLORINATED BIPHENYLS (PCBS).

EPA Science Inventory

The objective of the study was to assess the effects of developmental exposure to a commercial mixture of PCBs (Aroclor 1254) on neuronal dendritic morphology of hippocampal CA1 pyramidal neurons in postnatal day (PND) 22 and PND 60 male Long-Evans rats. Rat pups were born to mot...

Phenotypic Dichotomy Following Developmental Exposure to Perfluorooctanic Acid (PFOA) Exposure in CD-1 Mice: Low Doses Induce Elevated Serum, Leptin, Insulin, and Overweight in Mid-Life.

EPA Science Inventory

The synthetic surfactant, perfluorooctanoic acid (PFOA) is a proven developmental toxicant in mice, causing prenatal pregnancy loss, increased neonatal mortality, delayed eye opening, and abnormal mammary gland growth in animals exposed during fetal life. PFOA is found in the ser...

Developmental and behavioral consequences of prenatal methamphetamine exposure: a review of the Infant Development, Environment, and Lifestyle (IDEAL) Study

PubMed Central

Smith, Lynne M.; Diaz, Sabrina; LaGasse, Linda L.; Wouldes, Trecia; Derauf, Chris; Newman, Elana; Arria, Amelia; Huestis, Marilyn A.; Haning, William; Strauss, Arthur; Grotta, Sheri Della; Dansereau, Lynne M.; Neal, Charles; Lester, Barry M.

2015-01-01

This study reviews the findings from the Infant Development, Environment, and Lifestyle Study (IDEAL), a multisite, longitudinal, prospective study designed to determine maternal outcome and child growth and developmental findings following prenatal methamphetamine exposure from birth up to age 7.5 years. These findings are presented in the context of the home environment and caregiver characteristics to determine how the drug and the environment interact to affect the outcome of these children. No neonatal abstinence syndrome requiring pharmacologic intervention was observed but heavy drug exposure was associated with increased stress responses in the neonatal period. Poorer inhibitory control was also observed in heavy methamphetamine exposed children placing them at high risk for impaired executive function. Independent of methamphetamine exposure, children with more responsive home environments to developmental and emotional needs demonstrated lower risks for internalizing and externalizing behavior. PMID:26212684

Toxicity of Metals to a Freshwater Ostracod: Stenocypris major

PubMed Central

Shuhaimi-Othman, Mohammad; Yakub, Nadzifah; Ramle, Nur-Amalina; Abas, Ahmad

2011-01-01

Adults of freshwater ostracod Stenocypris major (Crustacea, Candonidae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed, and median lethal times (LT50) and concentrations (LC50) were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC50s for 96 hours for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 25.2, 13.1, 1189.8, 526.2, 19743.7, 278.9, 3101.9, and 510.2 μg/L, respectively. Metals bioconcentration in S. major increases with exposure to increasing concentrations, and Cd was the most toxic to S. major, followed by Cu, Fe, Mn, Pb, Zn, Al, and Ni (Cd>Cu>Fe>Mn>Pb>Zn>Al>Ni). Comparison of LC50 values for metals for this species with those for other freshwater crustacean reveals that S. major is equally or more sensitive to metals than most other tested crustacean. PMID:21559091

Controllable Growth of Perovskite Films by Room-Temperature Air Exposure for Efficient Planar Heterojunction Photovoltaic Cells.

PubMed

Yang, Bin; Dyck, Ondrej; Poplawsky, Jonathan; Keum, Jong; Das, Sanjib; Puretzky, Alexander; Aytug, Tolga; Joshi, Pooran C; Rouleau, Christopher M; Duscher, Gerd; Geohegan, David B; Xiao, Kai

2015-12-01

A two-step solution processing approach has been established to grow void-free perovskite films for low-cost high-performance planar heterojunction photovoltaic devices. A high-temperature thermal annealing treatment was applied to drive the diffusion of CH3NH3I precursor molecules into a compact PbI2 layer to form perovskite films. However, thermal annealing for extended periods led to degraded device performance owing to the defects generated by decomposition of perovskite into PbI2. A controllable layer-by-layer spin-coating method was used to grow "bilayer" CH3NH3I/PbI2 films, and then drive the interdiffusion between PbI2 and CH3NH3I layers by a simple air exposure at room temperature for making well-oriented, highly crystalline perovskite films without thermal annealing. This high degree of crystallinity resulted in a carrier diffusion length of ca. 800 nm and a high device efficiency of 15.6%, which is comparable to values reported for thermally annealed perovskite films. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Use of the sea hare (Aplysia fasciata) in marine pollution biomonitoring of harbors and bays.

PubMed

Dirrigl, Frank J; Badaoui, Zachariah; Tamez, Carlos; Vitek, Christopher J; Parsons, Jason G

2018-04-01

Our study evaluated heavy metal concentrations in soft tissues of sea hare, Aplysia fasciata, from the Lower Laguna Madre, Texas. Heavy metals in tissues followed Se>As>Pb>Cd. Concentrations ranged As (BDL-28.08), Cd (BDL-5.50), Pb (BDL-12.85) and Se (4.25-93.43ppm). Median As, Cd, Pb, and Se tissue levels exceeded exposure levels. Significant relationships occurred in metal-metal (AsCd, AsPb, CdPb, CdSe, and PbSe), metal-tissue (significant Se uptake by inhalant and exhalant siphons and As in the hepatopancreas), and metal-metal within tissue (AsPb in the hepatopancreas and CdPb in the digestive cecum) analyses (p<0.05). Bioaccumulation factors (BAF) suggested the inhalant siphon, hepatopancreas, and digestive cecum function as macroconcentrators of Cd, hepatopancreas and digestive cecum as macroconcentrators of Pb, and all tissues were deconcentrators for As and Se. As a bioaccumulator of heavy metals, Aplysia was evaluated as a bioindicator of marine pollution in harbors and bays. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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

2014-09-19

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

Epigenetics and the Developmental Origins of Health and Disease#

EPA Science Inventory

Epigenetic programming is likely to be an important mechanism underlying the lasting influence of the reproductive and developmental environment on lifelong health, a concept known as the Developmental Origins of Health and Disease (DOHaD). Environmental exposures including paren...

Comparative analysis on the effect of Lycopersicon esculentum (tomato) in reducing cadmium, mercury and lead accumulation in liver.

PubMed

Nwokocha, Chukwuemeka R; Nwokocha, Magdalene I; Aneto, Imaria; Obi, Joshua; Udekweleze, Damian C; Olatunde, Bukola; Owu, Daniel U; Iwuala, Moses O

2012-06-01

L. esculentum (tomato) contain compounds with anti-oxidant and anti-inflammatory properties, able to synthesize metal chelating proteins. We examined the ability of fruit extract to protect against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. Rats were fed on tomato mixed with rat chow (10% w/w), while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Tomato was administered together with the metals (group 2), a week after exposure (group 3) or a week before metal exposure (group 4) for a period of six weeks. The metal accumulations in the liver were determined using AAS. There was a significant (P<0.05) increase in protection by tomato to Cd and Hg accumulation but not to Pb (P<0.05) in weeks 2 and 4 for groups 2 and 3. The protective ability was significantly (P<0.05) increased for Pb in group 4, but was less comparable to Cd and Hg. Tomato reduces uptake while enhancing the elimination of these metals in a time dependent manner. The highest hepatoprotective effect was to Cd followed by Hg and least to Pb. Its administration is beneficial in reducing heavy metal accumulation in the liver. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multiple exposure and effects assessment of heavy metals in the population near mining area in South China.

PubMed

Zhuang, Ping; Lu, Huanping; Li, Zhian; Zou, Bi; McBride, Murray B

2014-01-01

The objective of this study was to investigate the levels of Cd, Pb, Cu and Zn in the environment and several important food sources grown and consumed in the vicinity of Dabaoshan mine in Southern China, and evaluate potential health risks among local residents. The Cd, Pb, Cu and Zn concentrations of arable soils and well water near the mines exceeded the quality standard values. The concentrations of Cd and Pb in some food crops (rice grain, vegetable and soybean) samples were significantly higher than the maximum permissible level. The Cd and Pb concentrations in half of the chicken and fish meat samples were higher than the national standard. The residents living near Dabaoshan mine had higher Cd and Pb levels in hair than those of a non-exposed population. The intake of rice was identified as a major contributor to the estimated daily intake of these metals by the residents. The hazard index values for adults and children were 10.25 and 11.11, respectively, with most of the estimated risks coming from the intake of home-grown rice and vegetables. This study highlights the importance of multiple pathways in studying health risk assessment of heavy metal exposure in China.

Multiple Exposure and Effects Assessment of Heavy Metals in the Population near Mining Area in South China

PubMed Central

Zhuang, Ping; Lu, Huanping; Li, Zhian; Zou, Bi; McBride, Murray B.

2014-01-01

The objective of this study was to investigate the levels of Cd, Pb, Cu and Zn in the environment and several important food sources grown and consumed in the vicinity of Dabaoshan mine in Southern China, and evaluate potential health risks among local residents. The Cd, Pb, Cu and Zn concentrations of arable soils and well water near the mines exceeded the quality standard values. The concentrations of Cd and Pb in some food crops (rice grain, vegetable and soybean) samples were significantly higher than the maximum permissible level. The Cd and Pb concentrations in half of the chicken and fish meat samples were higher than the national standard. The residents living near Dabaoshan mine had higher Cd and Pb levels in hair than those of a non-exposed population. The intake of rice was identified as a major contributor to the estimated daily intake of these metals by the residents. The hazard index values for adults and children were 10.25 and 11.11, respectively, with most of the estimated risks coming from the intake of home-grown rice and vegetables. This study highlights the importance of multiple pathways in studying health risk assessment of heavy metal exposure in China. PMID:24728502

Transdifferentiated rat pancreatic progenitor cells (AR42J-B13/H) respond to phenobarbital in a rat hepatocyte-specific manner.

PubMed

Osborne, M; Haltalli, M; Currie, R; Wright, J; Gooderham, N J

2016-07-01

Phenobarbital (PB) is known to produce species-specific effects in the rat and mouse, being carcinogenic in certain mouse strains, but only in rats if treated after a DNA damaging event. PB treatment in the rat and mouse also produces disparate effects on cell signalling and miRNA expression profiles. These responses are induced by short term and prolonged PB exposure, respectively, with the latter treatments being difficult to examine mechanistically in primary hepatocytes due to rapid loss of the original hepatic phenotype and limited sustainability in culture. Here we explore the rat hepatocyte-like B13/H cell line as a model for hepatic response to PB exposure in both short-term and longer duration treatments. We demonstrate that PB with Egf treatment in the B13/H cells resulted in a significant increase in Erk activation, as determined by the ratio of phospho-Erk to total Erk, compared to Egf alone. We also show that an extended treatment with PB in the B13/H cells produces a miRNA response similar to that seen in the rat in vivo, via the time-dependent induction of miR-182/96. Additionally, we confirm that B13/H cells respond to Car activators in a typical rat-specific manner. These data suggest that the B13/H cells produce temporal responses to PB that are comparable to those reported in short-term primary rat hepatocyte cultures and in the longer term are similar to those in the rat in vivo. Finally, we also show that Car-associated miR-122 expression is decreased by PB treatment in B13/H cells, a PB-induced response that is common to the rat, mouse and human. We conclude that the B13/H cell system produces a qualitative response comparable to the rat, which is different to the response in the mouse, and that this model could be a useful tool for exploring the functional consequences of PB-sensitive miRNA changes and resistance to PB-mediated tumours in the rat. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Violence in context: Embracing an ecological approach to violent media exposure.

PubMed

Glackin, Erin; Gray, Sarah A O

2016-12-01

This commentary expands on Anderson, Bushman, Donnerstein, Hummer, and Warburton's agenda for minimizing the impacts of violent media exposure (VME) on youth aggression. We argue that in order to effectively intervene in the development of aggression and other maladaptive traits, researchers and policymakers should take an ecological, developmental psychopathology approach to understanding children's exposure to VME within developmental, relational, environmental, and cultural contexts. Such a framework holds the most promise for identifying at-risk groups, establishing targets of intervention, and testing mechanisms of change.

Defining Nitrogen Kinetics for Air Break in Prebreath

NASA Technical Reports Server (NTRS)

Conkin, Johnny

2010-01-01

Actual tissue nitrogen (N2) kinetics are complex; the uptake and elimination is often approximated with a single half-time compartment in statistical descriptions of denitrogenation [prebreathe(PB)] protocols. Air breaks during PB complicate N2 kinetics. A comparison of symmetrical versus asymmetrical N2 kinetics was performed using the time to onset of hypobaric decompression sickness (DCS) as a surrogate for actual venous N2 tension. METHODS: Published results of 12 tests involving 179 hypobaric exposures in altitude chambers after PB, with and without airbreaks, provide the complex protocols from which to model N2 kinetics. DCS survival time for combined control and airbreaks were described with an accelerated log logistic model where N2 uptake and elimination before, during, and after the airbreak was computed with a simple exponential function or a function that changed half-time depending on ambient N2 partial pressure. P1N2-P2 = (Delta)P defined decompression dose for each altitude exposure, where P2 was the test altitude and P1N2 was computed N2 pressure at the beginning of the altitude exposure. RESULTS: The log likelihood (LL) without decompression dose (null model) was -155.6, and improved (best-fit) to -97.2 when dose was defined with a 240 min half-time for both N2 elimination and uptake during the PB. The description of DCS survival time was less precise with asymmetrical N2 kinetics, for example, LL was -98.9 with 240 min half-time elimination and 120 min half-time uptake. CONCLUSION: The statistical regression described survival time mechanistically linked to symmetrical N2 kinetics during PBs that also included airbreaks. The results are data-specific, and additional data may change the conclusion. The regression is useful to compute additional PB time to compensate for an airbreak in PB within the narrow range of tested conditions.

Defining Nitrogen Kinetics for Air Break in Prebreathe

NASA Technical Reports Server (NTRS)

Conkin, Johnny

2009-01-01

Actual tissue nitrogen (N2) kinetics are complex; the uptake and elimination is often approximated with a single half-time compartment in statistical descriptions of denitrogenation [prebreathe (PB)] protocols. Air breaks during PB complicate N2 kinetics. A comparison of symmetrical versus asymmetrical N2 kinetics was performed using the time to onset of hypobaric decompression sickness (DCS) as a surrogate for actual venous N2 tension. Published results of 12 tests involving 179 hypobaric exposures in altitude chambers after PB, with and without air breaks, provide the complex protocols from which to model N2 kinetics. DCS survival time for combined control and air breaks were described with an accelerated log logistic model where N2 uptake and elimination before, during, and after the air break was computed with a simple exponential function or a function that changed half-time depending on ambient N2 partial pressure. P1N2-P2 = delta P defined DCS dose for each altitude exposure, where P2 was the test altitude and P1N2 was computed N2 pressure at the beginning of the altitude exposure. The log likelihood (LL) without DCS dose (null model) was -155.6, and improved (best-fit) to -97.2 when dose was defined with a 240 min half-time for both N2 elimination and uptake during the PB. The description of DCS survival time was less precise with asymmetrical N2 kinetics, for example, LL was -98.9 with 240 min half-time elimination and 120 min half-time uptake. The statistical regression described survival time mechanistically linked to symmetrical N2 kinetics during PBs that also included air breaks. The results are data-specific, and additional data may change the conclusion. The regression is useful to compute additional PB time to compensate for an air break in PB within the narrow range of tested conditions.

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

PubMed

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

2017-11-08

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

Phytoextraction of Pb, Cr, Ni, and Zn using the aquatic plant Limnobium laevigatum and its potential use in the treatment of wastewater.

PubMed

Arán, Daniela Silvina; Harguinteguy, Carlos Alfredo; Fernandez-Cirelli, Alicia; Pignata, María Luisa

2017-08-01

In order to study the bioaccumulation of Pb, Cr, Ni, and Zn and the stress response, the floating aquatic plant Limnobium laevigatum was exposed to increasing concentrations of a mixture of these metals for 28 days, and its potential use in the treatment of wastewater was evaluated. The metal concentrations of the treatment 1 (T1) were Pb 1 μg L -1 , Cr 4 μg L -1 , Ni 25 μg L -1 , and Zn 30 μg L -1 ; of treatment 2 (T2) were Pb 70 μg L -1 , Cr 70 μg L -1 , Ni 70 μg L -1 , and Zn 70 μg L -1 ; and of treatment 3 (T3) were Pb 1000 μg L -1 , Cr 1000 μg L -1 , Ni 500 μg L -1 , and Zn 100 μg L -1 , and there was also a control group (without added metal). The accumulation of Pb, Cr, Ni, and Zn in roots was higher than in leaves of L. laevigatum, and the bioconcentration factor revealed that the concentrations of Ni and Zn in the leaf and root exceeded by over a thousand times the concentrations of those in the culture medium (2000 in leaf and 6800 in root for Ni; 3300 in leaf and 11,500 in root for Zn). Thus, this species can be considered as a hyperaccumulator of these metals. In general, the changes observed in the morphological and physiological parameters and the formation of products of lipid peroxidation of membranes during the exposure to moderate concentrations (T2) of the mixture of metals did not cause harmful effects to the survival of the species within the first 14 days of exposure. Taking into account the accumulation capacity and tolerance to heavy metals, L. laevigatum is suitable for phytoremediation in aquatic environments contaminated with moderated concentrations of Cr, Ni, Pb, and Zn in the early stages of exposure.

Protective effect of thymoquinone against lead-induced hepatic toxicity in rats.

PubMed

Mabrouk, Aymen; Bel Hadj Salah, Imen; Chaieb, Wafa; Ben Cheikh, Hassen

2016-06-01

Lead (Pb) intoxication is a worldwide health problem which frequently affects the liver. This study was carried out to investigate the potential protective effect of thymoquinone (TQ), the major active ingredient of volatile oil of Nigella sativa seeds, against Pb-induced liver damage. Adult male rats were randomized into four groups: Control group received no treatment, Pb group was exposed to 2000 ppm Pb acetate in drinking water, Pb-TQ group was cotreated with Pb plus TQ (5 mg/kg/day, per orally), and TQ group receiving only TQ. All treatments were applied for 5 weeks. Results indicated that Pb exposure increased hepatic Pb content, damaged hepatic histological structure (necrotic foci, hepatic strands disorganization, hypertrophied hepatocytes, cytoplasmic vacuolization, cytoplasmic loss, chromatin condensation, mononuclear cell infiltration, congestion, centrilobular swelling), and changed liver function investigated by plasma biochemical parameters (AST, ALT, ALP, γ-GT, LDH). Pb treatment also decreased total antioxidant status level and increased lipid peroxidation in the liver. Supplementation with TQ remarkably improved the Pb-induced adverse effects without significantly reducing the metal accumulation in the liver. In conclusion, our results indicate, for the first time, a protective effect of TQ against Pb-induced hepatotoxicity and suggest that this component might be clinically useful in Pb intoxication.

Assessing Metal Exposures in a Community near a Cement Plant in the Northeast U.S.

PubMed Central

Dong, Zhao; Bank, Michael S.; Spengler, John D.

2015-01-01

Cement production is a major source of metals and metalloids in the environment, while exposures to metals and metalloids may impact human health in the surrounding communities. We recruited 185 participants living in the vicinity of a cement plant in the northeast U.S., and measured the levels of aluminum (Al), arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), and selenium (Se) in blood and Hg in hair samples from them. A questionnaire was used to assess potential sources of Hg exposure. Multivariate regressions and spatial analyses were performed to evaluate the relative importance of different routes of exposures. The metal concentrations in blood or hair samples of our study participants were comparable to the U.S. general or regional population. Smoking contributed significantly to Cd and Pb exposures, and seafood consumption contributed significantly to Hg and As exposures, while variables related to the cement plant were not significantly associated with metal concentrations. Our results suggest that our study population was not at elevated health risk due to metal exposures, and that the contribution of the cement plant to metal exposures in the surrounding community was minimal. PMID:25607604

Accumulation of lead (Pb) in brown trout (Salmo trutta) from a lake downstream a former shooting range.

PubMed

Mariussen, Espen; Heier, Lene Sørlie; Teien, Hans Christian; Pettersen, Marit Nandrup; Holth, Tor Fredrik; Salbu, Brit; Rosseland, Bjørn Olav

2017-01-01

An environmental survey was performed in Lake Kyrtjønn, a small lake within an abandoned shooting range in the south of Norway. In Lake Kyrtjønn the total water concentrations of Pb (14µg/L), Cu (6.1µg/L) and Sb (1.3µg/L) were elevated compared to the nearby reference Lake Stitjønn, where the total concentrations of Pb, Cu and Sb were 0.76, 1.8 and 0.12µg/L, respectively. Brown trout (Salmo trutta) from Lake Kyrtjønn had very high levels of Pb in bone (104mg/kg w.w.), kidney (161mg/kg w.w.) and the gills (137mg/kg d.w), and a strong inhibition of the ALA-D enzyme activity were observed in the blood (24% of control). Dry fertilized brown trout eggs were placed in the small outlet streams from Lake Kyrtjønn and the reference lake for 6 months, and the concentrations of Pb and Cu in eggs from the Lake Kyrtjønn stream were significantly higher than in eggs from the reference. More than 90% of Pb accumulated in the egg shell, whereas more than 80% of the Cu and Zn accumulated in the egg interior. Pb in the lake sediments was elevated in the upper 2-5cm layer (410-2700mg/kg d.w), and was predominantly associated with redox sensitive fractions (e.g., organic materials, hydroxides) indicating low potential mobility and bioavailability of the deposited Pb. Only minor amounts of Cu and Sb were deposited in the sediments. The present work showed that the adult brown trout, as well as fertilized eggs and alevins, may be subjected to increased stress due to chronic exposure to Pb, whereas exposure to Cu, Zn and Sb were of less importance. Copyright © 2016 Elsevier Inc. All rights reserved.

Changes in subcellular distribution and antioxidant compounds involved in Pb accumulation and detoxification in Neyraudia reynaudiana.

PubMed

Zhou, Chuifan; Huang, Meiying; Li, Ying; Luo, Jiewen; Cai, Li Ping

2016-11-01

The effects of increasing concentrations of lead (Pb) on Pb accumulation, subcellular distribution, ultrastructure, photosynthetic characteristics, antioxidative enzyme activity, malondialdehyde content, and phytochelatin contents were investigated in Neyraudia reynaudiana seedlings after a 21-day exposure. A Pb analysis at the subcellular level showed that the majority of Pb in the roots was associated with the cell wall fraction, followed by the soluble fraction. In contrast, the majority of the Pb in the leaves was located in the soluble fraction based on transmission electron microscopy and energy dispersive X-ray analyses. Furthermore, high Pb concentrations adversely affected N. reynaudiana cellular structure. The changes in enzyme activity suggested that the antioxidant system plays an important role in eliminating or alleviating Pb toxicity, both in the roots and leaves of N. reynaudiana. Additionally, the phytochelatin contents in the roots and leaves differed significantly between Pb-spiked treatments and control plants. Our results provide strong evidence that cell walls restrict Pb uptake into the protoplasm and establish an important protective barrier. Subsequent vacuolar compartmentalization in leaves could isolate Pb from other substances in the cell and minimize Pb toxicity in other organelles over time. These results also demonstrated that the levels of antioxidant enzymes and phytochelatin in leaves and roots are correlated with Pb toxicity. These detoxification mechanisms promote Pb tolerance in N. reynaudiana.

Genetical Toxicogenomics in Drosophila Identifies Master Modulatory Loci that are Regulated by Developmental Exposure to Lead

PubMed Central

Ruden, Douglas M.; Chen, Lang; Possidente, Debra; Possidente, Bernard; Rasouli, Parsa; Wang, Luan; Lu, Xiangyi; Garfinkel, Mark D.; Hirsch, Helmut V. B.; Page, Grier P.

2009-01-01

The genetics of gene expression in recombinant inbred lines (RILs) can be mapped as expression quantitative trait loci (eQTLs). So-called “genetical genomics” studies have identified locally-acting eQTLs (cis-eQTLs) for genes that show differences in steady state RNA levels. These studies have also identified distantly-acting master-modulatory trans-eQTLs that regulate tens or hundreds of transcripts (hotspots or transbands). We expand on these studies by performing genetical genomics experiments in two environments in order to identify trans-eQTL that might be regulated by developmental exposure to the neurotoxin lead. Flies from each of 75 RIL were raised from eggs to adults on either control food (made with 250 µM sodium acetate), or lead-treated food (made with 250 µM lead acetate, PbAc). RNA expression analyses of whole adult male flies (5–10 days old) were performed with Affymetrix DrosII whole genome arrays (18,952 probesets). Among the 1,389 genes with cis-eQTL, there were 405 genes unique to control flies and 544 genes unique to lead-treated ones (440 genes had the same cis-eQTLs in both samples). There are 2,396 genes with trans-eQTL which mapped to 12 major transbands with greater than 95 genes. Permutation analyses of the strain labels but not the expression data suggests that the total number of eQTL and the number of transbands are more important criteria for validation than the size of the transband. Two transbands, one located on the 2nd chromosome and one on the 3rd chromosome, co-regulate 33 lead-induced genes, many of which are involved in neurodevelopmental processes. For these 33 genes, rather than allelic variation at one locus exerting differential effects in two environments, we found that variation at two different loci are required for optimal effects on lead-induced expression. PMID:19737576

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

PubMed

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

2012-01-01

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

Canonical Variate Analysis of Chlorophyll Content in Plants Exposed to Different Lead Concentrations in Ambient Air Conditions/ Analiza Zmiennych Kanonicznych Zawatości Chlorofilu W Roślinach Eksponowanych Na Różne Stężenia Ołowiu W Powietrzu Atmosferycznym

NASA Astrophysics Data System (ADS)

Budka, Anna; Kayzer, Dariusz; Zbierska, Janina; Borowiak, Klaudia; Barałkiewicz, Danuta; Hanć, Anetta

2014-09-01

Praca prezentuje rezultaty biomonitoringu ołowiu w zróżnicowanych warunkach środowiskowych. Do oceny zawartości poziomu ołowiu wykorzystano rośliny życicy wielokwiatowej. Dodatkowo w liściach oznaczono zawartość chlorofilu (a+b, a oraz b) w świeżej masie. Rośliny eksponowano w okresie wegetacyjnym roku 2011 na pięciu stanowiskach badawczych różniących się parametrami środowiskowymi oraz w warunkach kontrolnych. Rośliny eksponowano w 28-dniowych okresach badawczych. Wyniki zawartości Pb oraz poziomów chlorofili w różnych miejscach ekspozycyjnych oraz seriach testowano z zastosowaniem wielowymiarowej analizy wariancji. Wykazano zmienność zawartości Pb oraz poziomów wszystkich form chlorofilu w różnych miejscach ekspozycyjnych i seriach. Najniższe zawartości ołowiu oraz najwyższe poziomy wszystkich form chlorofilu zaobserwowano na stanowisku podmiejskim. W pracy wykazano przydatność analizy zmiennych kanonicznych do graficznej prezentacji wyników biomonitoringu powietrza. This paper presents the results of biomonitoring of Pb in ambient air. For this purpose Italian ryegrass was used to evaluate Pb level. Additionally chlorophyll forms (a+b, a and b) were measured in leaves. Plants were exposed at 5 sites varying in environmental characteristics in the 2011 growing season. A similar set of plants was conducted in control conditions. Three 28-day long exposure series were performed. The aim of this study was to analyse the relation between Pb level and chlorophyll content in various exposure sites and series using multivariate analysis of variance. The analysis revealed variability of Pb and all chlorophyll forms contents in different exposure sites and series. The lowest level of Pb concentrations was noted at a sub-urban site together with the highest level of all chlorophyll forms contents. Canonical variate analysis could be a proper tool for a graphical data presentation of Pb level in plants exposed to various environmental conditions.

Protein kinase C activation is required for the lead-induced inhibition of proliferation and differentiation of cultured oligodendroglial progenitor cells.

PubMed

Deng, Wenbin; Poretz, Ronald D

2002-03-01

Lead (Pb) is a common neurotoxicant of major public health concern. Previous studies revealed that cultured oligodendrocyte progenitor cells (OPCs) are highly vulnerable to Pb toxicity. The present study examines the effect of Pb on the survival, proliferation and differentiation of OPCs in vitro. Dose-response studies showed that> or = l5-10 microM Pb is cytotoxic to OPCs within 24 h. However, 1 microM of Pb was found to inhibit the proliferation and differentiation of OPCs without affecting cell viability. Pb markedly decreased the proliferative capability of OPCs and inhibited cell-intrinsic lineage progression of OPCs at a late progenitor stage. The Pb-induced decrease of proliferation and differentiation was abolished by inhibition of protein kinase C (PKC) with bisindolylmaleimide I, while the effect of the PKC-activating agent phorbol-12,13-didecanoate was potentiated by Pb. Furthermore, Pb exposure of OPCs caused the translocation of PKC from the cytoplasm to membrane without an increase in total cellular PKC enzymic activity. These results indicate that Pb inhibits the proliferation and differentiation of oligodendrocyte lineage cells in vitro through a mechanism requiring PKC activation.

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.

Does low to moderate environmental exposure to noise and air pollution influence preterm delivery in medium-sized cities?

PubMed

Barba-Vasseur, Marie; Bernard, Nadine; Pujol, Sophie; Sagot, Paul; Riethmuller, Didier; Thiriez, Gérard; Houot, Hélène; Defrance, Jérôme; Mariet, Anne-Sophie; Luu, Vinh-Phuc; Barbier, Alice; Benzenine, Eric; Quantin, Catherine; Mauny, Frédéric

2017-12-01

Preterm birth (PB) is an important predictor of childhood morbidity and educational performance. Beyond the known risk factors, environmental factors, such as air pollution and noise, have been implicated in PB. In urban areas, these pollutants coexist. Very few studies have examined the effects of multi-exposure on the pregnancy duration. The objective of this study was to analyse the relationship between PB and environmental chronic multi-exposure to noise and air pollution in medium-sized cities. A case-control study was conducted among women living in the city of Besançon (121 671 inhabitants) or in the urban unit of Dijon (243 936 inhabitants) and who delivered in a university hospital between 2005 and 2009. Only singleton pregnancies without associated pathologies were considered. Four controls were matched to each case in terms of the mother's age and delivery location. Residential noise and nitrogen dioxide (NO2) exposures were calculated at the mother's address. Conditional logistic regression models were applied, and sensitivity analyses were performed. This study included 302 cases and 1204 controls. The correlation between noise and NO2 indices ranged from 0.41 to 0.59. No significant differences were found in pollutant exposure levels between cases and controls. The adjusted odds ratios ranged between 0.96 and 1.08. Sensitivity analysis conducted using different temporal and spatial exposure windows demonstrated the same results. The results are in favour of a lack of connection between preterm delivery and multi-exposure to noise and air pollution in medium-sized cities for pregnant women without underlying disease. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

The effects of dietary lead on growth, bioaccumulation and antioxidant capacity in sea cucumber, Apostichopus japonicus.

PubMed

Wang, Jing; Ren, Tongjun; Han, Yuzhe; Zhao, Yang; Liao, Mingling; Wang, Fuqiang; Jiang, Zhiqiang

2015-09-01

Three different diets amended with lead nitrate [Pb(NO3)2] (100, 500 and 1000mg Pb/kg dry weight) and a Pb-free control diet (1.03mg Pb/kg dry weight) were fed to sea cucumber (Apostichopus japonicus) for 30 days. The patterns of Pb accumulation over time were determined in various tissues (body wall, intestine and respiratory tree), as well as growth performance and antioxidant enzymes activities. Pb accumulation in body wall and intestine increased with time in all dietary Pb treatments. When fed the highest Pb diet, the body wall exhibited the greatest Pb burden (16.37mg Pb/kg tissue wet weight), while Pb content in the intestine (2.68mg Pb/kg tissue wet weight) and the respiratory tree (1.78mg Pb/kg tissue wet weight) were lower than Pb content in the body wall by day 30. The body weight gain (BWG), specific growth rate (SGR) and survival rate (SR) had not been affected by 30 days oral administration of Pb supplemented diet. However, the antioxidant enzymes activities [superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)] of test groups were lower than control group in body wall and malondialdehyde (MDA) concentration in the body wall was opposite after 30 days in sea cucumbers. In summary, this work reports toxic effects in sea cucumber, A. japonicus, after dietary exposure to Pb. Copyright © 2015 Elsevier B.V. All rights reserved.

Metal intoxication in humans assessed by atomic and nuclear physics techniques

NASA Astrophysics Data System (ADS)

Chettle, David R.

1995-08-01

Toxic trace elements such as lead (Pb) and Cadmium (Cd) can be measured non-invasively in humans by radiation physics techniques, particularly x-ray fluorescence and neutron activation. An analysis is usually made of the content of a particular organ, representing the principal storage site of the element in question. For example, Pb is measured in bone, whereas Cd is measured in liver and kidney. Measuring stored quantities of these elements has contributed to assessment of health effects of chronic occupational and environmental exposure. In addition knowledge of the elemental metabolism has been significantly extended. Results of in vivo studies have also contributed to assessment and regulation of workplace exposure. Analogous methods are in use or under development for in vivo assay of mercury, aluminum, gold, platinum, and manganese. The principles of these measurements will be outlined and illustrative applications for Pb and Cd will be discussed.

The analysis of QT interval and repolarization morphology of the heart in chronic exposure to lead.

PubMed

Kiełtucki, J; Dobrakowski, M; Pawlas, N; Średniawa, B; Boroń, M; Kasperczyk, S

2017-10-01

There are no common recommendations regarding electrocardiographic monitoring in occupationally exposed workers. Therefore, the present study was designed to investigate whether exposure to lead results in an increase of selected electrocardiography (ECG) pathologies, such as QT interval prolongation and repolarization disorders, in occupationally exposed workers. The study group included 180 workers occupationally exposed to lead compounds. The exposed group was divided according to the median of the mean blood lead level (PbB mean ) calculated based on a series of measurements performed during 5-year observation period (35 µg/dl) into two subgroups: low exposure (LE, PbB mean = 20.0-35.0 µg/dl) and high exposure (HE, PbB mean = 35.1-46.4 µg/dl). The control group consisted of 69 healthy workers without occupational exposure to lead. ECG evaluation included the analysis of heart rate (HR), QT interval and repolarization abnormalities. Mean QT interval was significantly greater in the exposed population than in the control group by 2%. In the HE group, mean QT interval was significantly greater than in the control group by 4% and significantly different from those noted in the LE group. Positive correlations between QT interval and lead exposure indices were also reported. Besides, there was a negative correlation between HR and blood lead level. Increased concentration of lead in the blood above 35 μg/dl is associated with the QT interval prolongation, which may trigger arrhythmias when combined with other abnormalities, such as long QT syndrome. Therefore, electrocardiographic evaluation should be a part of a routine monitoring of occupationally exposed populations.

S-allyl cysteine in combination with clotrimazole downregulates Fas induced apoptotic events in erythrocytes of mice exposed to lead.

PubMed

Mandal, Samir; Mukherjee, Sudip; Chowdhury, Kaustav Dutta; Sarkar, Avik; Basu, Kankana; Paul, Soumosish; Karmakar, Debasish; Chatterjee, Mahasweta; Biswas, Tuli; Sadhukhan, Gobinda Chandra; Sen, Gargi

2012-01-01

Chronic lead (Pb(2+)) exposure leads to the reduced lifespan of erythrocytes. Oxidative stress and K(+) loss accelerate Fas translocation into lipid raft microdomains inducing Fas mediated death signaling in these erythrocytes. Pathophysiological-based therapeutic strategies to combat against erythrocyte death were evaluated using garlic-derived organosulfur compounds like diallyl disulfide (DADS), S allyl cysteine (SAC) and imidazole based Gardos channel inhibitor clotrimazole (CLT). Morphological alterations in erythrocytes were evaluated using scanning electron microscopy. Events associated with erythrocyte death were evaluated using radio labeled probes, flow cytometry and activity gel assay. Mass spectrometry was used for detection of GSH-4-hydroxy-trans-2-nonenal (HNE) adducts. Fas redistribution into the lipid rafts was studied using immunoblotting technique and confocal microscopy. Combination of SAC and CLT was better than DADS and CLT combination and monotherapy with these agents in prolonging the survival of erythrocytes during chronic Pb(2+) exposure. Combination therapy with SAC and CLT prevented redistribution of Fas into the lipid rafts of the plasma membrane and downregulated Fas-dependent death events in erythrocytes of mice exposed to Pb(2+). Ceramide generation was a critical component of Fas receptor-induced apoptosis, since inhibition of acid sphingomyelinase (aSMase) interfered with Fas-induced apoptosis during Pb(2+) exposure. Combination therapy with SAC and CLT downregulated apoptotic events in erythrocytes by antagonizing oxidative stress and Gardos channel that led to suppression of ceramide-initiated Fas aggregation in lipid rafts. Hence, combination therapy with SAC and CLT may be a potential therapeutic option for enhancing the lifespan of erythrocytes during Pb(2+) toxicity. Copyright © 2011 Elsevier B.V. All rights reserved.

New insights into the mechanism of phthalate-induced developmental effects.

PubMed

Mu, Xiyan; Huang, Ying; Li, Jia; Yang, Ke; Yang, Wenbo; Shen, Gongming; Li, Xuxing; Lei, Yunlei; Pang, Sen; Wang, Chengju; Li, Xuefeng; Li, Yingren

2018-06-11

To investigate the biological pathways involved in phthalate-induced developmental effects, zebrafish embryos were exposed to different concentrations of di-(2-ethylhexyl) (DEHP) and di-butyl phthalate (DBP) for 96 h. Embryonic exposure to DEHP and DBP induced body length decrease, yolk sac abnormities, and immune responses (up-regulation of immune proteins and genes). The lipidomic results showed that at a concentration of 50 μg/L, DEHP and DBP significantly reduced the levels of fatty acids, triglycerides, diacylglycerol, and cholesterol. These effects are partly explained by biological pathway enrichment based on data from the transcriptional and proteomic profiles. Co-exposure to DBP and ER antagonist did not significantly relieve the toxic symptoms compared with exposure to DBP alone. This indicates that phthalate-induced developmental abnormities in zebrafish might not be mediated by the ER pathway. In conclusion, we identified the possible biological pathways that mediate phthalate-induced developmental effects and found that these effects may not be driven by estrogenic activation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Personal exposures to airborne metals in London taxi drivers and office workers in 1995 and 1996.

PubMed

Pfeifer, G D; Harrison, R M; Lynam, D R

1999-09-01

In 1995, a petroleum marketer introduced a diesel fuel additive in the UK containing Mn as MMT (methylcyclopentadienyl manganese tricarbonyl). A small study of personal exposures to airborne Mn in London was conducted before and after introduction of the additive to identify any major impact of the additive on exposures. In 1995, personal exposures to Mn were measured in two groups, taxi drivers and office workers (10 subjects per group) for two consecutive 7-day periods. A similar study was carried out in 1996 to determine if exposures had changed. Samples were also analyzed for Ca, Al, Mg and Pb. In 1996, exposures to aerosol mass as total suspended particulates (TSP) and PM2.5 were measured in addition to the metals. Manganese exposures in this cohort did not increase as a result of introduction of the additive. However, a significant source of Mn exposure was discovered during the conduct of these tests. The mean exposure to Mn was higher among the office workers in both years than that of the taxi drivers. This was due to the fact that approximately half of the office workers commuted via the underground railway system where airborne dust and metal concentrations are significantly elevated over those in the general environment. Similar results have been noted in other cities having underground rail systems. Exposure to Mn, Pb, Ca, and Mg were not significantly different between the 2 years. Taxi drivers had higher exposures than office workers to Mg and Pb in both years. Commuting via the underground also had a significant impact on exposures to TSP, PM2.5, Al, and Ca, but had little effect on exposures to Mg. The aerosol in the underground was particularly enriched in Mn, approximately 10-fold, when compared to the aerosol in the general environment. There are several possible sources for this Mn, including mechanical wear of the steel wheels on the steel rais, vaporization of metal from sparking of the third rail, or brake wear.

Life Events as Correlates of Problem Behavior and Mental Health in a Residential Population of Adults with Developmental Disabilities

ERIC Educational Resources Information Center

Owen, Dawn M.; Hastings, Richard P.; Noone, Stephen J.; Chinn, Joanna; Harman, Kattie; Roberts, Julia; Taylor, Kelly

2004-01-01

Very few existing empirical studies have explored the putative association between exposure to negative life events and psychological well-being in adults with developmental disabilities. In the present study, data on exposure to life events in the previous 12 months, adaptive behavior, problem behavior, and psychiatric problems were provided by…

Use of Dried Blood Spots for Estimating Children?s Exposures to Heavy Metals in Epidemiological Research

EPA Science Inventory

Background: Children’s exposures to arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) are of particular concern in early-life. Exposures to heavy metals are traditionally measured in whole venous blood, which is costly and invasive. As an alternative we describe a met...

Developmental Programming: Priming Disease Susceptibility for Subsequent Generations.

PubMed

Messer, L C; Boone-Heinonen, J; Mponwane, L; Wallack, L; Thornburg, K L

2015-03-01

Racial and/or ethnic minorities carry the highest burden of many adverse health outcomes intergenerationally We propose a paradigm in which developmental programming exacerbates the effects of racial patterning of adverse environmental conditions, thereby contributing to health disparity persistence. Evidence that developmental programming induces a heightened response to adverse exposures ("second hits") encountered later in life is considered. We evaluated the evidence for the second hit phenomenon reported in animal and human studies from three domains (air, stress, nutrition). Original research including a gestational exposure and a childhood or adulthood second hit exposure was reviewed. Evidence from animal studies suggest that prenatal exposure to air pollutants is associated with an exaggerated reaction to postnatal air pollution exposure, which results in worse health outcomes. It also indicates offspring exposed to prenatal maternal stress produce an exaggerated response to subsequent stressors, including anxiety and hyper-responsiveness of the hypothalamic-pituitary-adrenal axis. Similarly, prenatal and postnatal Western-style diets induce synergistic effects on weight gain, metabolic dysfunction, and atherosclerotic risk. Cross-domain second hits (e.g., gestational air pollution followed by childhood stressor) were also considered. Suboptimal gestational environments induce exaggerated offspring responses to subsequent environmental and social exposures. These developmental programming effects may result in enhanced sensitivity of ongoing, racially patterned, adverse exposures in race/ethnic minorities, thereby exacerbating health disparities from one generation to the next. Empirical assessment of the hypothesized role of priming processes in the propagation of health disparities is needed. Future social epidemiology research must explicitly consider synergistic relationships among social environmental conditions to which gestating females are exposed and offspring exposures when assessing causes for persistent health disparities.

Developmental Programming: Priming Disease Susceptibility for Subsequent Generations

PubMed Central

Boone-Heinonen, J.; Mponwane, L.; Wallack, L.; Thornburg, K. L.

2015-01-01

Racial and/or ethnic minorities carry the highest burden of many adverse health outcomes intergenerationally We propose a paradigm in which developmental programming exacerbates the effects of racial patterning of adverse environmental conditions, thereby contributing to health disparity persistence. Evidence that developmental programming induces a heightened response to adverse exposures (“second hits”) encountered later in life is considered. We evaluated the evidence for the second hit phenomenon reported in animal and human studies from three domains (air, stress, nutrition). Original research including a gestational exposure and a childhood or adulthood second hit exposure was reviewed. Evidence from animal studies suggest that prenatal exposure to air pollutants is associated with an exaggerated reaction to postnatal air pollution exposure, which results in worse health outcomes. It also indicates offspring exposed to prenatal maternal stress produce an exaggerated response to subsequent stressors, including anxiety and hyper-responsiveness of the hypothalamic–pituitary–adrenal axis. Similarly, prenatal and postnatal Western-style diets induce synergistic effects on weight gain, metabolic dysfunction, and atherosclerotic risk. Cross-domain second hits (e.g., gestational air pollution followed by childhood stressor) were also considered. Suboptimal gestational environments induce exaggerated offspring responses to subsequent environmental and social exposures. These developmental programming effects may result in enhanced sensitivity of ongoing, racially patterned, adverse exposures in race/ethnic minorities, thereby exacerbating health disparities from one generation to the next. Empirical assessment of the hypothesized role of priming processes in the propagation of health disparities is needed. Future social epidemiology research must explicitly consider synergistic relationships among social environmental conditions to which gestating females are exposed and offspring exposures when assessing causes for persistent health disparities. PMID:26366336

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.

Field isotopic study of lead fate and compartmentalization in earthworm-soil-metal particle systems for highly polluted soil near Pb recycling factory.

PubMed

Goix, Sylvaine; Mombo, Stéphane; Schreck, Eva; Pierart, Antoine; Lévêque, Thibaut; Deola, Frédéric; Dumat, Camille

2015-11-01

Earthworms are important organisms in soil macrofauna and play a key role in soil functionality, and consequently in terrestrial ecotoxicological risk assessments. Because they are frequently observed in soils strongly polluted by metals, the influence of earthworm bioturbation on Pb fate could therefore be studied through the use of Pb isotopes. Total Pb concentrations and isotopic composition ((206)Pb, (207)Pb and (208)Pb) were then measured in earthworms, casts and bulk soils sampled at different distance from a lead recycling factory. Results showed decreasing Pb concentrations with the distance from the factory whatever the considered matrix (bulk soils, earthworm bodies or cast samples) with higher concentrations in bulk soils than in cast samples. The bivariate plot (208)Pb/(206)Pb ratios versus (206)Pb/(207)Pb ratios showed that all samples can be considered as a linear mixing between metallic process particulate matter (PM) and geochemical Pb background. Calculated anthropogenic fraction of Pb varied between approximately 84% and 100%. Based on Pb isotopic signatures, the comparison between casts, earthworms and bulk soils allowed to conclude that earthworms preferentially ingest the anthropogenic lead fraction associated with coarse soil organic matter. Actually, soil organic matter was better correlated with Pb isotopic ratios than with Pb content in soils. The proposed hypothesis is therefore a decrease of soil organic matter turnover due to Pb pollution with consequences on Pb distribution in soils and earthworm exposure. Finally, Pb isotopes analysis constitutes an efficient tool to study the influence of earthworm bioturbation on Pb cycle in polluted soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

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

2016-12-01

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

Cadmium, mercury, and lead in kidney cortex of living kidney donors: Impact of different exposure sources,

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

Barregard, Lars, E-mail: lars.barregard@amm.gu.se; Fabricius-Lagging, Elisabeth; Lundh, Thomas

Background: Most current knowledge on kidney concentrations of nephrotoxic metals like cadmium (Cd), mercury (Hg), or lead (Pb) comes from autopsy studies. Assessment of metal concentrations in kidney biopsies from living subjects can be combined with information about exposure sources like smoking, diet, and occupation supplied by the biopsied subjects themselves. Objectives: To determine kidney concentrations of Cd, Hg, and Pb in living kidney donors, and assess associations with common exposure sources and background factors. Methods: Metal concentrations were determined in 109 living kidney donors aged 24-70 years (median 51), using inductively coupled plasma-mass spectrometry (Cd and Pb) and coldmore » vapor atomic fluorescence spectrometry (Hg). Smoking habits, occupation, dental amalgam, fish consumption, and iron stores were evaluated. Results: The median kidney concentrations were 12.9 {mu}g/g (wet weight) for cadmium, 0.21 {mu}g/g for mercury, and 0.08 {mu}g/g for lead. Kidney Cd increased by 3.9 {mu}g/g for a 10 year increase in age, and by 3.7 {mu}g/g for an extra 10 pack-years of smoking. Levels in non-smokers were similar to those found in the 1970s. Low iron stores (low serum ferritin) in women increased kidney Cd by 4.5 {mu}g/g. Kidney Hg increased by 6% for every additional amalgam surface, but was not associated with fish consumption. Lead was unaffected by the background factors surveyed. Conclusions: In Sweden, kidney Cd levels have decreased due to less smoking, while the impact of diet seems unchanged. Dental amalgam is the main determinant of kidney Hg. Kidney Pb levels are very low due to decreased exposure.« less

Accumulation and sub-cellular partitioning of metals and As in the clam Venerupis corrugata: Different strategies towards different elements.

PubMed

Velez, Cátia; Figueira, Etelvina; Soares, Amadeu M V M; Freitas, Rosa

2016-08-01

The main goal of the present study was to assess accumulation, tolerance and sub-cellular partitioning of As, Hg, Cd and Pb in Venerupis corrugata. Results showed an increase of elements accumulation in V. corrugata with the increase of exposure. However, organisms presented higher capacity to accumulate Hg, Cd and Pb (BCF ≥ 12.8) than As (BCF ≤ 2.1) and higher accumulation rate for Cd and Pb than for Hg and As. With the increase of Hg exposure concentrations clams tended to increase the amount of metal bound to metal-sensitive fractions, which may explain the mortality recorded at the highest exposure concentration. Cd sub-cellular partitioning showed that with the increase of exposure concentrations V. corrugata increased the amount of metal in the cellular debris fraction, probably bound to the cellular membranes which explain the mortality recorded at the highest concentration. Results on As partitioning demonstrated that most of the metalloid was associated with fractions in the biologically detoxified metal compartment (BDM). Since high mortality was observed in clams exposed to As our results may indicate that this strategy was not enough to prevent clams from toxic effects and mortality occurred. When exposed to Pb most of the metal was in the BDM compartment, but in this case the metal was mostly in the metal-rich granules fraction which seemed to be efficient in preventing clams from toxicity, and no mortality was recorded. Our study further revealed that As and Hg were the most available elements to be biomagnified through the food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Persistent Na+ and K+ channel dysfunctions after chronic exposure to insecticides and pyridostigmine bromide.

PubMed

Nutter, T J; Jiang, N; Cooper, Brian Y

2013-12-01

Many soldiers that served in the 1991 Gulf War developed widespread chronic pain. Exposure to insecticides and the nerve gas prophylactic pyridostigmine bromide (PB) was identified as risk factors by the Research Advisory Committee on Gulf War Veterans' Illnesses (GWI). We examined whether a 60 day exposure to neurotoxicants/PB (NTPB) produced behavioral, molecular and cellular indices of chronic pain in the rat. Male rats were exposed to chlorpyrifos (120mg/kg; SC), permethrin (2.6mg/kg; topical), and PB (13.0mg/kg; oral) or their respective vehicles (corn oil, ethanol, and water). Permethrin can exert profound influences on voltage activated Na(+) channel proteins; while chlorpyrifos and PB can increase absorption and/or retard metabolism of permethrin as well as inhibit cholinesterases. During and after exposure to these agents, we assessed muscle pressure pain thresholds and activity (distance and rest time). Eight and 12 weeks after treatments ceased, we used whole cell patch electrophysiology to examine the physiology of tissue specific DRG nociceptor channel proteins expressed in muscle and putative vascular nociceptors (voltage dependent, activation, inactivation, and deactivation). Behavioral indices were unchanged after treatment with NTPB. Eight weeks after treatments ended, the peak and average conductance of Kv7 mediated K(+) currents were significantly increased in vascular nociceptors. When a specific Kv7 inhibitor was applied (linopirdine, 10μM) NTPB treated vascular nociceptors emitted significantly more spontaneous APs than vehicle treated neurons. Changes to Kv7 channel physiology were resolved 12 weeks after treatment. The molecular alterations to Kv7 channel proteins and the specific susceptibility of the vascular nociceptor population could be important for the etiology of GWI pain. Copyright © 2013 Elsevier Inc. All rights reserved.

Microarray-based bioinformatics analysis of the combined effects of SiNPs and PbAc on cardiovascular system in zebrafish.

PubMed

Hu, Hejing; Zhang, Yannan; Shi, Yanfeng; Feng, Lin; Duan, Junchao; Sun, Zhiwei

2017-10-01

With rapid development of nanotechnology and growing environmental pollution, the combined toxic effects of SiNPs and pollutants of heavy metals like lead have received global attentions. The aim of this study was to explore the cardiovascular effects of the co-exposure of SiNPs and lead acetate (PbAc) in zebrafish using microarray and bioinformatics analysis. Although there was no other obvious cardiovascular malformation except bleeding phenotype, bradycardia, angiogenesis inhibition and declined cardiac output in zebrafish co-exposed of SiNPs and PbAc at NOAEL level, significant changes were observed in mRNA and microRNA (miRNA) expression patterns. STC-GO analysis indicated that the co-exposure might have more toxic effects on cardiovascular system than that exposure alone. Key differentially expressed genes were discerned out based on the Dynamic-gene-network, including stxbp1a, ndfip2, celf4 and gsk3b. Furthermore, several miRNAs obtained from the miRNA-Gene-Network might play crucial roles in cardiovascular disease, such as dre-miR-93, dre-miR-34a, dre-miR-181c, dre-miR-7145, dre-miR-730, dre-miR-129-5p, dre-miR-19d, dre-miR-218b, dre-miR-221. Besides, the analysis of miRNA-pathway-network indicated that the zebrafish were stimulated by the co-exposure of SiNPs and PbAc, which might cause the disturbance of calcium homeostasis and endoplasmic reticulum stress. As a result, cardiac muscle contraction might be deteriorated. In general, our data provide abundant fundamental research clues to the combined toxicity of environmental pollutants and further in-depth verifications are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Tetrabromobisphenol A and heavy metal exposure via dust ingestion in an e-waste recycling region in Southeast China.

PubMed

Wu, Yuanyuan; Li, Yanyan; Kang, Duan; Wang, Jingjing; Zhang, Yanfang; Du, Dongli; Pan, Bishu; Lin, Zhenkun; Huang, Changjiang; Dong, Qiaoxiang

2016-01-15

This study was designed to investigate a prevalent brominated flame retardant tetrabromobisphenol A (TBBPA) and four heavy metals of Pb, Cr, As, Cd in dust samples (52 indoor and 52 outdoor) collected from residential houses in an e-waste recycling area in Southeast China. For TBBPA, the mean concentration in indoor dust (3435 ng/g, dw) was higher than that in outdoor dust (1998 ng/g, dw). For heavy metals, the mean concentrations of Pb, Cr, As, Cd were 399, 151, 48.13, and 5.85 mg/kg in indoor dust, respectively, and were 328, 191, 17.59, and 4.07 mg/kg in outdoor dust, respectively. Except for As, concentrations of TBBPA and other metals decreased with the increased distance away from the e-waste recycling center, suggesting significant contribution of e-waste activities. The daily exposure doses of TBBPA ranged from 0.04 to 7.50 ng/kg-bw/day for adults and from 0.31 to 58.54 ng/kg-bw/day for children, representing the highest values reported to date for TBBPA exposure via dust ingestion. Daily exposure doses of Cr, As, and Cd were all below the reference doses. However, daily exposure dose of Pb for children in areas near the e-waste processing center was above the reference dose, posing significant health concern for children in that region. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrochemical Sensors for the Detection of Lead and Other Toxic Heavy Metals: The Next Generation of Personal Exposure Biomonitors

PubMed Central

Yantasee, Wassana; Lin, Yuehe; Hongsirikarn, Kitiya; Fryxell, Glen E.; Addleman, Raymond; Timchalk, Charles

2007-01-01

To support the development and implementation of biological monitoring programs, we need quantitative technologies for measuring xenobiotic exposure. Microanalytical based sensors that work with complex biomatrices such as blood, urine, or saliva are being developed and validated and will improve our ability to make definitive associations between chemical exposures and disease. Among toxic metals, lead continues to be one of the most problematic. Despite considerable efforts to identify and eliminate Pb exposure sources, this metal remains a significant health concern, particularly for young children. Ongoing research focuses on the development of portable metal analyzers that have many advantages over current available technologies, thus potentially representing the next generation of toxic metal analyzers. In this article, we highlight the development and validation of two classes of metal analyzers for the voltammetric detection of Pb, including: a) an analyzer based on flow injection analysis and anodic stripping voltammetry at a mercury-film electrode, and b) Hg-free metal analyzers employing adsorptive stripping voltammetry and novel nanostructure materials that include the self-assembled monolayers on mesoporous supports and carbon nanotubes. These sensors have been optimized to detect Pb in urine, blood, and saliva as accurately as the state-of-the-art inductively coupled plasma-mass spectrometry with high reproducibility, and sensitivity allows. These improved and portable analytical sensor platforms will facilitate our ability to conduct biological monitoring programs to understand the relationship between chemical exposure assessment and disease outcomes. PMID:18087583

Effects of distance and depth on total and bioaccessible lead in soils from two farmhouses in Beltsville, Maryland

USDA-ARS?s Scientific Manuscript database

Renewed interests in home gardening heighten the concern of human lead exposure. Negative effects of lead on human health are well known. Horizontal and vertical movement of lead (Pb) around houses has been studied, but Pb bioaccessiblity as a function of distance and depth from the house needs to...

Risk Assessment and Implication of Human Exposure to Road Dust Heavy Metals in Jeddah, Saudi Arabia

PubMed Central

Shabbaj, Ibrahim I.; Alghamdi, Mansour A.; Shamy, Magdy; Alsharif, Musaab M.; Khoder, Mamdouh I.

2017-01-01

Data dealing with the assessment of heavy metal pollution in road dusts in Jeddah, Saudi Arabia and its implication to human health risk of human exposure to heavy metals, are scarce. Road dusts were collected from five different functional areas (traffic areas (TA), parking areas (PA), residential areas (RA), mixed residential commercial areas (MCRA) and suburban areas (SA)) in Jeddah and one in a rural area (RUA) in Hada Al Sham. We aimed to measure the pollution levels of heavy metals and estimate their health risk of human exposure applying risk assessment models described by United States Environmental Protection Agency (USEPA). Using geo-accumulation index (Igeo), the pollution level of heavy metals in urban road dusts was in the following order Cd > As > Pb > Zn > Cu > Ni > Cr > V > Mn > Co > Fe. Urban road dust was found to be moderately to heavily contaminated with As, Pb and Zn, and heavily to extremely contaminated with Cd. Calculation of enrichment factor (EF) revealed that heavy metals in TA had the highest values compared to that of the other functional areas. Cd, As, Pb, Zn and Cu were severely enriched, while Mn, V, Co, Ni and Cr were moderately enriched. Fe was considered as a natural element and consequently excluded. The concentrations of heavy metals in road dusts of functional areas were in the following order: TA > PA > MCRA > SA > RA > RUA. The study revealed that both children and adults in all studied areas having health quotient (HQ) < 1 are at negligible non-carcinogenic risk. The only exception was for children exposed to As in TA. They had an ingestion health quotient (HQing) 1.18 and a health index (HI) 1.19. The most prominent exposure route was ingestion. The cancer risk for children and adults from exposure to Pb, Cd, Co, Ni, and Cr was found to be negligible (≤1 × 10−6). PMID:29278373

Content of Heavy Metal in the Dust of Leisure Squares and Its Health Risk Assessment-A Case Study of Yanta District in Xi'an.

PubMed

Shao, Tianjie; Pan, Lihuan; Chen, Zhiqing; Wang, Ruiyuan; Li, Wenjing; Qin, Qing; He, Yuran

2018-02-25

Taking Yanta District in Xi'an as the research object, the present study measures the contents of Cadmium (Cd), Lead (Pb), Copper (Cu), Nickel (Ni), and Chromium (Cr) in dust samples and further assesses the health risk of heavy metals intake through dust based on the assessment method of human exposure risk proposed by U.S. EPA, with an aim to investigate the content of heavy metal in the dust of leisure squares and its exposure risk. As the results indicate, the average contents of five heavy metals are obviously higher than the soil background value in Shaanxi Province. Therefore, Cd, Ni, Cu, Pb, and Cr are obviously enriched in urban surface dust in Shaanxi Province, due to the influence of human activities. In addition, it can also be found that the non-carcinogen exposure risk in children is significantly higher than that in adults with the risk values of these five heavy metals all one order of magnitude higher than those of adults. Irrespective of whether addressing the results for children or adults, the non-carcinogen exposure doses of five heavy metals are sorted as Cr > Pb > Cu > Ni > Cd. According to the present situation, for a child, the total non-carcinogenic risk values of five heavy metals have exceeded the safety limit in 11 of the 20 leisure squares in Yanta District of Xi'an. That means the leisure squares are no longer suitable for physical and recreational activities. For the five heavy metals, the average non-carcinogenic risk value of Cr is largest, and causes the largest threat to health in Yanta District, Xi'an. The carcinogenic exposure doses of the heavy metals Cr, Cd, and Ni are very low in respiratory pathways and there is no carcinogenic health risk. In general, the Cr content in dust in domestic cities is higher than that of foreign cities; however, the Pb content is much lower.

Assessment of attention and inhibitory control in rodent developmental neurotoxicity studies.

PubMed

Driscoll, Lori L; Strupp, Barbara J

2015-01-01

In designing screens to assess potential neurotoxicants, the paramount goal is that the selected assessment tools detect dysfunction if it exists. This goal is particularly challenging in the case of cognitive assessments. Cognition is not a unitary phenomenon, and indeed there is growing evidence that different aspects of cognitive functioning are subserved by distinct neural systems. As a result, if a particular neurotoxicant selectively damages certain neural systems but not others, it can impair some cognitive, sensory, or affective functions, but leave many others intact. Accordingly, studies with human subjects use batteries of cognitive tests, cognizant of the fact that no one test is capable of detecting all forms of cognitive dysfunction. In contrast, assessment of cognitive functioning in non-human animal developmental neurotoxicity (DNT) studies typically consists of a single, presumably representative, "learning and memory" task that is expected to detect all potential effects on cognitive functioning. Streamlining the cognitive assessment in these studies saves time and money, but these shortcuts can have serious consequences if the aspect of cognitive functioning that is impaired is not tapped by the single selected task. In particular, executive functioning - a constellation of cognitive functions which enables the organism to focus on multiple streams of information simultaneously, and revise plans as necessary - is poorly assessed in most animal DNT studies. The failure to adequately assess these functions - which include attention, working memory, inhibitory control, and planning - is particularly worrisome in light of evidence that the neural systems that subserve these functions may be uniquely vulnerable to early developmental insults. We illustrate the importance of tapping these areas of functioning in DNT studies by describing the pattern of effects produced by early developmental Pb exposure. Rats exposed to lead (Pb) early in development were tested on a series of automated attention tasks, as well as on a radial arm maze task. The lead-exposed rats were not impaired in this demanding radial arm maze task, despite conditions which tapped the limits of both working and long-term memory. In contrast, the automated tests designed to assess rodent executive functioning revealed selective and functionally important deficits in attention and regulation of emotion or negative affect (produced by committing an error or not receiving an expected reward). This example underscores the importance of including tasks to specifically tap executive functioning in DNT batteries. Such tasks are not only sensitive but can also shed light on the specific nature of the dysfunction, and they can implicate dysfunction of specific neural systems, information which can be used to design therapeutic interventions. Although the use of such tasks increases the time and effort needed to complete the battery, the benefits outweigh the cost, in light of the greater sensitivity of the battery and the more complete characterization of effects. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Adverse Associations of both Prenatal and Postnatal Exposure to Organophosphorous Pesticides with Infant Neurodevelopment in an Agricultural Area of Jiangsu Province, China

PubMed Central

Liu, Ping; Wu, Chunhua; Chang, Xiuli; Qi, Xiaojuan; Zheng, Minglan; Zhou, Zhijun

2016-01-01

Background: Prenatal exposure to organophosphorous (OP) pesticides has been found to be associated with adverse effects on child neurodevelopment, but evidence on potential effects induced by both prenatal and postnatal OP exposure in infants is limited. Objectives: Our aim was to investigate the associations of both prenatal and postnatal OP exposure with birth outcomes and infant neurodevelopment. Methods: Exposure to OP in 310 mother–infant pairs was assessed by measuring dimethylphosphate (DM), diethylphosphate (DE), and total dialkylphosphate (DAP) metabolites in urines from pregnant women and their children at 2 years of age. The Gesell Developmental Schedules was administered to examine neurodevelopment of 2-year-old children. Results: Based on the Gesell Developmental Schedules, the proportions of children with developmental delays were < 6%. Adverse associations between head circumference at birth and prenatal OP exposure were demonstrated. Both prenatal and postnatal OP exposure was significantly associated with increased risk of being developmentally delayed. Specifically, odds ratio (OR) value for prenatal DEs was 9.75 (95% CI: 1.28, 73.98, p = 0.028) in the adaptive area, whereas in the social area, OR values for postnatal DEs and DAPs were 9.56 (95% CI: 1.59, 57.57, p = 0.014) and 12.00 (95% CI: 1.23, 117.37, p = 0.033), respectively. Adverse associations were observed only in boys, not in girls. Conclusions: Both prenatal and postnatal OP exposure may adversely affect the neurodevelopment of infants living in the agricultural area. The present study adds to the accumulating evidence on associations of prenatal and postnatal OP exposure with infant neurodevelopment. Citation: Liu P, Wu C, Chang X, Qi X, Zheng M, Zhou Z. 2016. Adverse associations of both prenatal and postnatal exposure to organophosphorous pesticides with infant neurodevelopment in an agricultural area of Jiangsu Province, China. Environ Health Perspect 124:1637–1643; http://dx.doi.org/10.1289/EHP196 PMID:27153333

Relationship between blood lead level and work related factors using the NIIH questionnaire system.

PubMed

Saito, Hiroyuki; Mori, Ippei; Ogawa, Yasutaka; Hirata, Mamoru

2006-10-01

Over an 11-yr period (1990-2000), a questionnaire survey on work environmental management and environmental improvement was conducted on 259 lead-handling factories and 7,623 subjects. Labour Inspection Offices identified these factories as requiring environmental improvement, or possessing a desire to improve their working environment. We analyzed factors affecting blood lead levels (PbBs). These factors were gender, age, employment duration, factory size, work environment control (WEC) class, and job categories. The PbB of men was found to be higher than that of women, and may be due to the differences in job distribution. PbB increased along with increasing age and employment duration. PbB declined as the factory size increased. The odds ratio (OR) of PbB higher than 20 microg/dl according to factory size was significantly high even after adjusting for WEC class. This demonstrates that not only the working environment but also safety management was poorer among small-scale factories that large-scale factories. The rise of PbB along with the increase of WEC class confirmed that the results of work environment measurement are correlated with individual exposure levels. The risk of having a 20 microg/dl or higher PbB was different for various lead handling jobs. Smelting or refining lead had the highest risk for lead exposure while painting or baking had the lowest risk. As our study population was not a randomly selected sample, we are unable to generalize our results for workers across Japan. However, we were able to indicate which jobs pose a high-risk and the effectiveness of using the work environment control class as an index of worksite environment levels.

Hunting with lead: association between blood lead levels and wild game consumption.

PubMed

Iqbal, Shahed; Blumenthal, Wendy; Kennedy, Chinaro; Yip, Fuyuen Y; Pickard, Stephen; Flanders, W Dana; Loringer, Kelly; Kruger, Kirby; Caldwell, Kathleen L; Jean Brown, Mary

2009-11-01

Wild game hunting is a popular activity in many regions of the United States. Recently, the presence of lead fragments in wild game meat, presumably from the bullets or shot used for hunting, has raised concerns about health risks from meat consumption. This study examined the association between blood lead levels (PbB) and wild game consumption. We recruited 742 participants, aged 2-92 years, from six North Dakota cities. Blood lead samples were collected from 736 persons. Information on socio-demographic background, housing, lead exposure source, and types of wild game consumption (i.e., venison, other game such as moose, birds) was also collected. Generalized estimating equations (GEE) were used to determine the association between PbB and wild game consumption. Most participants reported consuming wild game (80.8%) obtained from hunting (98.8%). The geometric mean PbB were 1.27 and 0.84 microg/dl among persons who did and did not consume wild game, respectively. After adjusting for potential confounders, persons who consumed wild game had 0.30 microg/dl (95% confidence interval: 0.16-0.44 microg/dl) higher PbB than persons who did not. For all game types, recent (<1 month) wild game consumption was associated with higher PbB. PbB was also higher among those who consumed a larger serving size (> or = 2 oz vs. <2 oz); however, this association was significant for 'other game' consumption only. Participants who consumed wild game had higher PbB than those who did not consume wild game. Careful review of butchering practices and monitoring of meat-packing processes may decrease lead exposure from wild game consumption.

Brain Hemispheric Differences in the Neurochemical Effects of Lead, Prenatal Stress, and the Combination and Their Amelioration by Behavioral Experience

PubMed Central

Cory-Slechta, Deborah A.

2013-01-01

Brain lateralization, critical to mediation of cognitive functions and to “multitasking,” is disrupted in conditions such as attention deficit disorder and schizophrenia. Both low-level lead (Pb) exposure and prenatal stress (PS) have been associated with mesocorticolimbic system–mediated executive-function cognitive and attention deficits. Mesocorticolimbic systems demonstrate significant laterality. Thus, altered brain lateralization could play a role in this behavioral toxicity. This study examined laterality of mesocorticolimbic monoamines (frontal cortex, nucleus accumbens, striatum, midbrain) and amino acids (frontal cortex) in male and female rats subjected to lifetime Pb exposure (0 or 50 ppm in drinking water), PS (restraint stress on gestational days 16–17), or the combination with and without repeated learning behavioral experience. Control males exhibited prominent laterality, particularly in midbrain and also in frontal cortex and striatum; females exhibited less laterality, and this was primarily striatal. Lateralized Pb ± PS induced neurotransmitter changes were assessed only in males because of limited sample sizes of Pb + PS females. In males, Pb ± PS changes occurred in left hemisphere of frontal cortex and right hemisphere of midbrain. Behavioral experience modified the laterality of Pb ± PS–induced neurotransmitter changes in a region-dependent manner. Notably, behavioral experience eliminated Pb ± PS neurotransmitter changes in males. These findings underscore the critical need to evaluate both sexes and brain hemispheres for the mechanistic understanding of sex-dependent differences in neuro- and behavioral toxicity. Furthermore, assessment of central nervous system mechanisms in the absence of behavioral experience, shown here for males, may constitute less relevant models of human health effects. PMID:23358193

Feather lead concentrations and (207)Pb/(206)Pb ratios reveal lead exposure history of California Condors (Gymnogyps californianus).

PubMed

Finkelstein, M E; George, D; Scherbinski, S; Gwiazda, R; Johnson, M; Burnett, J; Brandt, J; Lawrey, S; Pessier, A P; Clark, M; Wynne, J; Grantham, J; Smith, D R

2010-04-01

Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only approximately 10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant of population health, our findings should increase the understanding of population-level effects from lead poisoning in condors; this information may also be helpful for other avian species potentially impacted by lead poisoning.

Feather lead concentrations and 207Pb/206Pb ratios reveal lead exposure history of California Condors (Gymnogyps californianus)

USGS Publications Warehouse

Finkelstein, M.E.; George, D.; Scherbinski, S.; Gwiazda, R.; Johnson, M.; Burnett, J.; Brandt, J.; Lawrey, S.; Pessier, Allan P.; Clark, M.R.; Wynne, J.; Grantham, And J.; Smith, D.R.

2010-01-01

Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only ∼10% of a bird’s annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird’s lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2−4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant of population health, our findings should increase the understanding of population-level effects from lead poisoning in condors; this information may also be helpful for other avian species potentially impacted by lead poisoning.