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Twardy SM, Hanson SM, Jursa T, Gaitens JM, Kalinich JM, McDiarmid MA, Smith DR. Succimer chelation does not produce lasting reductions of blood lead levels in a rodent model of retained lead fragments. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 104:104283. [PMID: 37775076 DOI: 10.1016/j.etap.2023.104283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 09/20/2023] [Accepted: 09/23/2023] [Indexed: 10/01/2023]
Abstract
Retained lead fragments from nonfatal firearm injuries pose a risk of lead poisoning. While chelation is well-established as a lead poisoning treatment, it remains unclear whether chelation mobilizes lead from embedded lead fragments. Here, we tested whether 1) DMSA/succimer or CaNa2EDTA increases mobilization of lead from fragments in vitro, and 2) succimer is efficacious in chelating fragment lead in vivo, using stable lead isotope tracer methods in a rodent model of embedded fragments. DMSA was > 10-times more effective than CaNa2EDTA in mobilizing fragment lead in vitro. In the rodent model, succimer chelation on day 1 produced the greatest blood lead reductions, and fragment lead was not mobilized into blood. However, with continued chelation and over 3-weeks post-chelation, blood lead levels rebounded with mobilization of lead from the fragments. These findings suggest prolonged chelation will increase fragment lead mobilization post-chelation, supporting the need for long-term surveillance in patients with retained fragments.
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Affiliation(s)
- Shannon M Twardy
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - Sarah M Hanson
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - Thomas Jursa
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - Joanna M Gaitens
- Division of Occupational and Environmental Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - John M Kalinich
- Division of Occupational and Environmental Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Melissa A McDiarmid
- Division of Occupational and Environmental Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Don R Smith
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA.
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2
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Early-life low-level lead exposure alters anxiety-like behavior, voluntary alcohol consumption and AC5 protein content in adult male and female C57BL/6 J mice. Neurotoxicol Teratol 2023; 95:107149. [PMID: 36539102 DOI: 10.1016/j.ntt.2022.107149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Despite efforts to eradicate sources of environmental lead (Pb), children, predominately in lower socioeconomic areas, are still frequently exposed to unsafe levels of Pb from soils, dust, and water. Human studies suggest that Pb exposure is associated with altered drug consumption in adults; however, there is limited research at comparable exposure levels (blood Pb levels <10 μg/dL). To model how early-life, low-level Pb exposure affects alcohol consumption in adulthood, we exposed postnatal day (PND) 21 C57Bl/6 J mice to either 30 ppm or 0 ppm Lead (IV) Acetate in distilled water until PND 42, and testing began in adulthood. We predicted that mice with early-life Pb exposure would exhibit greater anxiety-like behavior and consume more alcohol in a three-week Drinking-in-the-Dark procedure (20% v/v) and a 24-h two-bottle choice procedure (10% v/v). We also predicted that Pb exposure would decrease whole-brain content of Adenylate Cyclase-5 (AC5), a protein linked to anxiety-like behaviors and alcohol drinking. There was no difference in limited-access binge-like consumption between exposure groups; however, Pb-exposed mice displayed higher two-bottle choice alcohol intake and preference. Furthermore, Pb-exposed mice exhibited greater anxiety-like behaviors in experiments conducted before an alcohol drinking history but not after. Finally, Pb-exposed mice exhibited an upregulation of whole-brain AC5 protein content. However, this difference was not found in the nucleus accumbens, dorsomedial or dorsolateral striatum. These findings conclude that early-life Pb exposure alters voluntary alcohol consumption and whole-brain AC5 protein content in adulthood. Future studies are necessary to further understand the mechanism behind how Pb exposure alters alcohol intake.
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3
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Becker F, Marcantonio F, Datta S, Wichterich C, Cizmas L, Surber J, Kennedy K, Bowles E. Tracking the source of contaminant lead in children's blood. ENVIRONMENTAL RESEARCH 2022; 212:113307. [PMID: 35447155 DOI: 10.1016/j.envres.2022.113307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/09/2022] [Accepted: 04/10/2022] [Indexed: 06/14/2023]
Abstract
Pb isotope ratios are used for apportioning the sources of Pb in the blood of children (ages 1-6) screened for high blood Pb levels (>5 μg/dL) surrounding urban areas of Kansas City, MO. We compared Pb isotope ratios measured in the child's blood with those of the most likely sources of Pb in that child's home environment. The environmental sources sampled consisted of topsoils, paints, occupational sources (e.g., oil rig workers' uniforms, mechanics' clothes), indoor air filters, dusts, and dietary sources (e.g., spices). Blood lead levels (BLL) ranged from 2.9 to 12.7 μg/dL in children from the five homes participating in this study. Measurements of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb isotope ratios were made by multi-collector ICP-MS. Comparison of the Pb isotope ratios in home environment samples versus those in the child's blood in each home allowed the identification of possible sources of a child's Pb exposure in three homes. In five homes investigated, children's blood Pb levels were most likely to be derived from dusts inside, and topsoil outside, the homes, or a mixture thereof. In one case, blood Pb was derived from turmeric spice and, in another, the Pb was derived from paint. It is not always possible to directly link high BLLs to the environmental sources collected when Pb isotope ratios of the environmental samples did not overlap with those of the blood.
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Affiliation(s)
- F Becker
- Department of Geology and Geophysics, Texas A&M University, College Station, TX, USA
| | - F Marcantonio
- Department of Geology and Geophysics, Texas A&M University, College Station, TX, USA.
| | - S Datta
- Department of Earth and Planetary Sciences, University of Texas, San Antonio, TX, USA
| | - C Wichterich
- Department of Geology and Geophysics, Texas A&M University, College Station, TX, USA
| | - L Cizmas
- School of Public Health, Texas A&M University, College Station, TX, USA
| | - J Surber
- Department of Geology, Kansas State University, Manhattan, KS, USA
| | - K Kennedy
- Children's Mercy Kansas City Environmental Health Program, Kansas City, MO, USA
| | - E Bowles
- Children's Mercy Kansas City Environmental Health Program, Kansas City, MO, USA
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Clases D, Gonzalez de Vega R. Facets of ICP-MS and their potential in the medical sciences-Part 1: fundamentals, stand-alone and hyphenated techniques. Anal Bioanal Chem 2022; 414:7337-7361. [PMID: 36028724 PMCID: PMC9482897 DOI: 10.1007/s00216-022-04259-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/26/2022] [Accepted: 07/29/2022] [Indexed: 12/02/2022]
Abstract
Since its inception in the early 80s, inductively coupled plasma–mass spectrometry has developed to the method of choice for the analysis of elements in complex biological systems. High sensitivity paired with isotopic selectivity and a vast dynamic range endorsed ICP-MS for the inquiry of metals in the context of biomedical questions. In a stand-alone configuration, it has optimal qualities for the biomonitoring of major, trace and toxicologically relevant elements and may further be employed for the characterisation of disrupted metabolic pathways in the context of diverse pathologies. The on-line coupling to laser ablation (LA) and chromatography expanded the scope and application range of ICP-MS and set benchmarks for accurate and quantitative speciation analysis and element bioimaging. Furthermore, isotopic analysis provided new avenues to reveal an altered metabolism, for the application of tracers and for calibration approaches. In the last two decades, the scope of ICP-MS was further expanded and inspired by the introduction of new instrumentation and methodologies including novel and improved hardware as well as immunochemical methods. These additions caused a paradigm shift for the biomedical application of ICP-MS and its impact in the medical sciences and enabled the analysis of individual cells, their microenvironment, nanomaterials considered for medical applications, analysis of biomolecules and the design of novel bioassays. These new facets are gradually recognised in the medical communities and several clinical trials are underway. Altogether, ICP-MS emerged as an extremely versatile technique with a vast potential to provide novel insights and complementary perspectives and to push the limits in the medical disciplines. This review will introduce the different facets of ICP-MS and will be divided into two parts. The first part will cover instrumental basics, technological advances, and fundamental considerations as well as traditional and current applications of ICP-MS and its hyphenated techniques in the context of biomonitoring, bioimaging and elemental speciation. The second part will build on this fundament and describe more recent directions with an emphasis on nanomedicine, immunochemistry, mass cytometry and novel bioassays.
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Affiliation(s)
- David Clases
- Nano Mirco LAB, Institute of Chemistry, University of Graz, Graz, Austria.
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Brown MJ, Kemper AR. Considering Screening When There May Be Minimal Direct Benefit to the Child. Pediatrics 2021; 148:s40-s44. [PMID: 34210847 DOI: 10.1542/peds.2021-050693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 11/24/2022] Open
Affiliation(s)
- Mary Jean Brown
- Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Alex R Kemper
- Division of Primary Care Pediatrics, Nationwide Children's Hospital, Columbus, Ohio
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Pareja-Carrera J, Martinez-Haro M, Mateo R, Rodríguez-Estival J. Effect of mineral supplementation on lead bioavailability and toxicity biomarkers in sheep exposed to mining pollution. ENVIRONMENTAL RESEARCH 2021; 196:110364. [PMID: 33131708 DOI: 10.1016/j.envres.2020.110364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
The chronic exposure of livestock to lead (Pb) pollution in historical mining areas may represent significant and unnecessary costs for farmers and primary producers, in addition to important food safety risks. Here, we evaluate the effect of mineral supplements, in the form of a commercial mineral block (MB), to reduce Pb bioavailability and toxicity in sheep through an experimental approach under real farming conditions in an abandoned mining area. Blood, fecal Pb levels, and soil ingestion, along with different blood and plasma biomarkers were studied. Experiment 1 was carried out with 3-months-old female lambs, n = 54, fenced in two contiguous MB and non-MB-supplemented plots. After 20 days of treatment, blood Pb level was lower in MB-supplemented sheep than in those that were non-MB-supplemented. Experiment 2 was carried out with 2-months-old female lambs, n = 34, fenced in a single plot and MB-supplemented during the first 20 days of experiment. After MB supplementation, blood Pb level in sheep was also reduced by almost half, falling below the threshold of subclinical intoxication, and then increased again after 20 days without MB. Experiment 3 was carried out with adult rams, n = 10, fenced in a single MB-supplemented plot during the first 20 days of experiment. In this case, blood Pb level decreased by day 40. Soil ingestion was not reduced by MB supplementation in any of the experiments. MB supplementation favored antioxidant status by increasing SOD activity and reducing GPX activity and MDA levels. In conclusion, the MB supplementation seemed to reduce Pb bioavailability by increasing its fecal excretion, but renal excretion and bone deposition may also have favored the reduction of blood Pb concentration. Mineral supplements may be a new easy-to-apply and cost-effective way to reduce livestock exposure in Pb polluted sites.
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Affiliation(s)
- Jennifer Pareja-Carrera
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain
| | - Mónica Martinez-Haro
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain; Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), CIAG Del Chaparrillo, 13071, Ciudad Real, Spain.
| | - Rafael Mateo
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain
| | - Jaime Rodríguez-Estival
- Instituto de Investigación en Recursos Cinegéticos (IREC - CSIC, UCLM, JCCM), Ronda de Toledo 12, 13005, Ciudad Real, Spain; Instituto de Tecnología, Construcción y Telecomunicaciones (ITct), Universidad de Castilla-La Mancha (UCLM), Calle de Pedro Almodovar 1, 16002, Cuenca, Spain; Azeral Environmental Sciences, STIPA & AZERAL Environmental Services, S. L., Avenida de Los Alfares 24, 2° A, 16002, Cuenca, Spain
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7
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Cadmium and Lead Exposure, Nephrotoxicity, and Mortality. TOXICS 2020; 8:toxics8040086. [PMID: 33066165 PMCID: PMC7711868 DOI: 10.3390/toxics8040086] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/07/2020] [Accepted: 10/11/2020] [Indexed: 12/11/2022]
Abstract
The present review aims to provide an update on health risks associated with the low-to-moderate levels of environmental cadmium (Cd) and lead (Pb) to which most populations are exposed. Epidemiological studies examining the adverse effects of coexposure to Cd and Pb have shown that Pb may enhance the nephrotoxicity of Cd and vice versa. Herein, the existing tolerable intake levels of Cd and Pb are discussed together with the conventional urinary Cd threshold limit of 5.24 μg/g creatinine. Dietary sources of Cd and Pb and the intake levels reported for average consumers in the U.S., Spain, Korea, Germany and China are summarized. The utility of urine, whole blood, plasma/serum, and erythrocytes to quantify exposure levels of Cd and Pb are discussed. Epidemiological studies that linked one of these measurements to risks of chronic kidney disease (CKD) and mortality from common ailments are reviewed. A Cd intake level of 23.2 μg/day, which is less than half the safe intake stated by the guidelines, may increase the risk of CKD by 73%, and urinary Cd levels one-tenth of the threshold limit, defined by excessive ß2-microglobulin excretion, were associated with increased risk of CKD, mortality from heart disease, cancer of any site and Alzheimer's disease. These findings indicate that the current tolerable intake of Cd and the conventional urinary Cd threshold limit do not provide adequate health protection. Any excessive Cd excretion is probably indicative of tubular injury. In light of the evolving realization of the interaction between Cd and Pb, actions to minimize environmental exposure to these toxic metals are imperative.
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Nussbaumer-Streit B, Mayr V, Dobrescu AI, Wagner G, Chapman A, Pfadenhauer LM, Lohner S, Lhachimi SK, Busert LK, Gartlehner G. Household interventions for secondary prevention of domestic lead exposure in children. Cochrane Database Syst Rev 2020; 10:CD006047. [PMID: 33022752 PMCID: PMC8094406 DOI: 10.1002/14651858.cd006047.pub6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Lead exposure is a serious health hazard, especially for children. It is associated with physical, cognitive and neurobehavioural impairment in children. There are many potential sources of lead in the environment, therefore trials have tested many household interventions to prevent or reduce lead exposure. This is an update of a previously published review. OBJECTIVES To assess the effects of household interventions intended to prevent or reduce further lead exposure in children on improvements in cognitive and neurobehavioural development, reductions in blood lead levels and reductions in household dust lead levels. SEARCH METHODS In March 2020, we updated our searches of CENTRAL, MEDLINE, Embase, 10 other databases and ClinicalTrials.gov. We also searched Google Scholar, checked the reference lists of relevant studies and contacted experts to identify unpublished studies. SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs of household educational or environmental interventions, or combinations of interventions to prevent lead exposure in children (from birth to 18 years of age), where investigators reported at least one standardised outcome measure. DATA COLLECTION AND ANALYSIS Two authors independently reviewed all eligible studies for inclusion, assessed risk of bias and extracted data. We contacted trialists to obtain missing information. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS We included 17 studies (three new to this update), involving 3282 children: 16 RCTs (involving 3204 children) and one quasi-RCT (involving 78 children). Children in all studies were under six years of age. Fifteen studies took place in urban areas of North America, one in Australia and one in China. Most studies were in areas with low socioeconomic status. Girls and boys were equally represented in those studies reporting this information. The duration of the intervention ranged from three months to 24 months in 15 studies, while two studies performed interventions on a single occasion. Follow-up periods ranged from three months to eight years. Three RCTs were at low risk of bias in all assessed domains. The other 14 studies were at unclear or high risk of bias; for example, we considered two RCTs and one quasi-RCT at high risk of selection bias and six RCTs at high risk of attrition bias. National or international research grants or governments funded 15 studies, while the other two did not report their funding sources. Education interventions versus no intervention None of the included studies in this comparison assessed effects on cognitive or neurobehavioural outcomes, or adverse events. All studies reported data on blood lead level outcomes. Educational interventions showed there was probably no evidence of a difference in reducing blood lead levels (continuous: mean difference (MD) -0.03, 95% confidence interval (CI) -0.13 to 0.07; I² = 0%; 5 studies, 815 participants; moderate-certainty evidence; log-transformed data), or in reducing floor dust levels (MD -0.07, 95% CI -0.37 to 0.24; I² = 0%; 2 studies, 318 participants; moderate-certainty evidence). Environmental interventions versus no intervention Dust control: one study in this comparison reported data on cognitive and neurobehavioural outcomes, and on adverse events in children. The study showed numerically there may be better neurobehavioural outcomes in children of the intervention group. However, differences were small and the CI included both a beneficial and non-beneficial effect of the environmental intervention (e.g. mental development (Bayley Scales of Infant Development-II): MD 0.1, 95% CI -2.1 to 2.4; 1 study, 302 participants; low-certainty evidence). The same study did not observe any adverse events related to the intervention during the eight-year follow-up, but observed two children with adverse events in the control group (1 study, 355 participants; very low-certainty evidence). Meta-analysis also found no evidence of effectiveness on blood lead levels (continuous: MD -0.02, 95% CI -0.09 to 0.06; I² = 0%; 4 studies, 565 participants; moderate-certainty evidence; log-transformed data). We could not pool the data regarding floor dust levels, but studies reported that there may be no evidence of a difference between the groups (very low-certainty evidence). Soil abatement: the two studies assessing this environmental intervention only reported on the outcome of 'blood lead level'. One study showed a small effect on blood lead level reduction, while the other study showed no effect. Therefore, we deem the current evidence insufficient to draw conclusions about the effectiveness of soil abatement (very low-certainty evidence). Combination of educational and environmental interventions versus standard education Studies in this comparison only reported on blood lead levels and dust lead levels. We could not pool the studies in a meta-analysis due to substantial differences between the studies. Since the studies reported inconsistent results, the evidence is currently insufficient to clarify whether a combination of interventions reduces blood lead levels and floor dust levels (very low-certainty evidence). AUTHORS' CONCLUSIONS Based on available evidence, household educational interventions and environmental interventions (namely dust control measures) show no evidence of a difference in reducing blood lead levels in children as a population health measure. The evidence of the effects of environmental interventions on cognitive and neurobehavioural outcomes and adverse events is uncertain too. Further trials are required to establish the most effective intervention for reducing or even preventing further lead exposure. Key elements of these trials should include strategies to reduce multiple sources of lead exposure simultaneously using empirical dust clearance levels. It is also necessary for trials to be carried out in low- and middle-income countries and in differing socioeconomic groups in high-income countries.
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Affiliation(s)
- Barbara Nussbaumer-Streit
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems, Austria
| | - Verena Mayr
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems, Austria
| | - Andreea Iulia Dobrescu
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems, Austria
| | - Gernot Wagner
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems, Austria
| | - Andrea Chapman
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems, Austria
| | - Lisa M Pfadenhauer
- Institute for Medical Information Processing, Biometry and Epidemiology, IBE, LMU Munich, Munich, Germany
| | - Szimonetta Lohner
- Cochrane Hungary, Clinical Center of the University of Pécs, Medical School, University of Pécs, Pécs, Hungary
| | - Stefan K Lhachimi
- Research Group for Evidence-Based Public Health, Leibniz Institute for Prevention Research and Epidemiology, Bremen, Germany
- Department for Health Services Research, Institute for Public Health and Nursing Research, Health Sciences Bremen, University of Bremen, Bremen, Germany
| | - Laura K Busert
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Gerald Gartlehner
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems, Austria
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Dantzer J, Ryan P, Yolton K, Parsons PJ, Palmer CD, Cecil K, Unrine JM. A comparison of blood and toenails as biomarkers of children's exposure to lead and their correlation with cognitive function. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 700:134519. [PMID: 31698272 PMCID: PMC6939637 DOI: 10.1016/j.scitotenv.2019.134519] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 05/25/2023]
Abstract
This study sought to compare lead (Pb) concentrations in toenails and blood and to investigate the association of each biomarker with children's cognitive function. Toenails and whole blood samples were collected from 224 twelve-year-old children, and their full-scale intelligence quotient (FSIQ) was assessed using the Wechsler Intelligence Scale for Children-4th edition. Inductively coupled plasma-mass spectrometry was used to determine blood (BPb) and toenail (TPb) Pb concentrations. Log BPb and Log TPb were significantly correlated (r2 = 0.49, p < 0.001). In unadjusted analyses, both log-transformed BPb and TPb were significantly associated with decreased FSIQ, but BPb accounted for approximately quadruple the FSIQ scores' variability than log-transformed TPb (model R2 = 0.12 and R2 = 0.03, respectively). After adjusting for neighborhood deprivation, caregiver intelligence (assessed with the Wechsler Abbreviated Scale of Intelligence-2nd edition), and child BMI, BPb remained significantly associated with decreased FSIQ, while TPb did not (p = 0.16). These results suggest that while concentrations of Pb in blood and toenails are correlated, TPb does not predict cognitive outcomes at these exposure levels. With caution and in conjunction with BPb, TPb may be used as a population-based biomarker of Pb exposure.
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Affiliation(s)
- Julianna Dantzer
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
| | - Patrick Ryan
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kimberly Yolton
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Division of General and Community Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Patrick J Parsons
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, USA; Department of Environmental Health Sciences, School of Public Health, The University of Albany, Rennselaer, NY, USA
| | - Christopher D Palmer
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, USA; Department of Environmental Health Sciences, School of Public Health, The University of Albany, Rennselaer, NY, USA
| | - Kim Cecil
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Jason M Unrine
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA; Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY, USA.
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10
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McClelland SC, Durães Ribeiro R, Mielke HW, Finkelstein ME, Gonzales CR, Jones JA, Komdeur J, Derryberry E, Saltzberg EB, Karubian J. Sub-lethal exposure to lead is associated with heightened aggression in an urban songbird. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:593-603. [PMID: 30447598 DOI: 10.1016/j.scitotenv.2018.11.145] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/09/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
Many urban areas have elevated soil lead concentrations due to prior large-scale use of lead in products such as paint and automobile gasoline. This presents a potential problem for the growing numbers of wildlife living in urbanized areas as lead exposure is known to affect multiple physiological systems, including the nervous system, in vertebrate species. In humans and laboratory animals, low-level lead exposure is associated with neurological impairment, but less is known about how lead may affect the behavior of urban wildlife. We focused on the Northern Mockingbird Mimus polyglottos, a common, omnivorous North American songbird, to gain insights into how lead may affect the physiology and behavior of urban wildlife. We predicted that birds living in neighborhoods with high soil lead concentrations would (a) exhibit elevated lead concentrations in their blood and feathers, (b) exhibit lower body condition, (c) exhibit less diverse and consistent vocal repertoires, and (d) behave more aggressively during simulated conspecific territorial intrusions compared to birds living in neighborhoods with lower soil lead concentrations. Controlling for other habitat differences, we found that birds from areas of high soil lead had elevated lead concentrations in blood and feathers, but found no differences in body condition or vocal repertoires. However, birds from high lead areas responded more aggressively during simulated intrusions. These findings indicate that sub-lethal lead exposure may be common among wildlife living in urban areas, and that this exposure is associated with increased aggression. Better understanding of the extent of the relationship between lead exposure and aggression and the consequences this could have for survival and reproduction of wild animals are clear priorities for future work in this and other urban ecosystems.
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Affiliation(s)
- Stephanie C McClelland
- Behavioural Ecology and Physiology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands; School of Biological Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK.
| | - Renata Durães Ribeiro
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
| | - Howard W Mielke
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Myra E Finkelstein
- Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA, USA
| | | | - John Anthony Jones
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
| | - Jan Komdeur
- Behavioural Ecology and Physiology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands
| | - Elizabeth Derryberry
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA; Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Emma B Saltzberg
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
| | - Jordan Karubian
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
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11
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Olympio KPK, Silva JPDR, Silva ASD, Souza VCDO, Buzalaf MAR, Barbosa F, Cardoso MRA. Blood lead and cadmium levels in preschool children and associated risk factors in São Paulo, Brazil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 240:831-838. [PMID: 29783200 DOI: 10.1016/j.envpol.2018.04.124] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
In Brazil, there are scarce data on lead (Pb) and cadmium (Cd) contamination, especially for more vulnerable populations such as preschool children. In this paper, we answer two questions: (1) What are the exposure levels of lead and cadmium in preschool children, in Sao Paulo, Brazil? and (2) What are the risk factors associated with this exposure? This cross-sectional study included 50 day care centers (DCCs), totaling 2463 children aged 1-4 years. Venous blood samples were analyzed by ICP-MS. Questionnaires were administered to the parents. Multiple logistic regression models were used to identify associations between blood lead levels (BLLs) and blood cadmium levels (BCLs) and potential risk factors. The geometric mean for BLLs was 2.16 μg/dL (95% CI: 2.10-2.22 μg/dL), and the 97.5th percentile was 13.9 μg/dL (95% CI: 10.0-17.3 μg/dL). For cadmium exposure, the geometric mean for BCLs was 0.48 μg/L (95% CI: 0.47-0.50 μg/L), and the 95th percentile was 2.57 μg/L (95% CI: 2.26-2.75 μg/L). The DCCs' geographic region was associated with high BLLs and BCLs, indicating hot spots for lead and cadmium exposures. In addition, it was found that the higher the vehicles flow, the higher were the BLLs in children. Red lead in household gates was also an important risk factor for lead exposure. Comparing these results with the findings of the Fourth National Report on Human Exposure to Environmental Chemicals by CDC-2013, it was found that in Brazilian preschool children the BLLs are almost three times higher (97.5th percentile) and the BCLs are almost twelve times higher (95th percentile) than those in U.S. children. This information is essential to formulate public health policies.
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Affiliation(s)
| | | | - Agnes Soares da Silva
- Communicable Diseases and Environmental Determinants of Health (CDE), Pan American Health Organization, PAHO/WHO, Washington, DC, USA
| | - Vanessa Cristina de Oliveira Souza
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Marília Afonso Rabelo Buzalaf
- Departamento de Ciências Biológicas, Faculdade de Odontologia de Bauru, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Fernando Barbosa
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Maria Regina Alves Cardoso
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
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How Does Low Socioeconomic Status Increase Blood Lead Levelsin KoreanChildren? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15071488. [PMID: 30011877 PMCID: PMC6068902 DOI: 10.3390/ijerph15071488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/06/2018] [Accepted: 07/10/2018] [Indexed: 11/23/2022]
Abstract
Although studies have shown that a low socioeconomic status (SES) is associated with high blood lead levels (BLLs) in children, the mechanism underlying this observation is not well known. To determine how SES influences BLLs via environmental factors in Korean children, we conducted a population-based cross-sectional study of 4744 children aged 5–13 years. Questionnaires on sociodemographic information, environmental factors, and food consumption were administered to the children’s parents. BLLs in the study subjects were measured.The complete set of hypothesized associations was assessed using regression analysis and structural equation modeling. SES was associated with high BLLs. The total effects of nutritional factors, lead in the air and total length of nearby roads, and agriculture on BLLs were −0.062 (p < 0.001), 0.068 (p = 0.005), and 0.038 (p = 0.035), respectively. The direct effects of playing outdoors and SES on BLLs were 0.113 (p < 0.001) and −0.111 (p < 0.001), respectively. Although playing outdoors had a greater direct effect on BLLs than did SES, the total effect of SES (standardized β = −0.132, p < 0.001) was greater than that of other sources owing to indirect effects (β = −0.020, p = 0.004). A low SES was a major risk factor for elevated BLLs via environmental factors.
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Yabe J, Nakayama SMM, Ikenaka Y, Yohannes YB, Bortey-Sam N, Kabalo AN, Ntapisha J, Mizukawa H, Umemura T, Ishizuka M. Lead and cadmium excretion in feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia. CHEMOSPHERE 2018; 202:48-55. [PMID: 29554507 DOI: 10.1016/j.chemosphere.2018.03.079] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/24/2018] [Accepted: 03/11/2018] [Indexed: 06/08/2023]
Abstract
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.
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Affiliation(s)
- John Yabe
- The University of Zambia, School of Veterinary Medicine, P.O. Box 32379, Lusaka, Zambia
| | - Shouta M M Nakayama
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Yoshinori Ikenaka
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Yared B Yohannes
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Nesta Bortey-Sam
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | | | - John Ntapisha
- Ministry of Health, District Health Office, P.O. Box 80735, Kabwe, Zambia
| | - Hazuki Mizukawa
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Takashi Umemura
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Mayumi Ishizuka
- Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan.
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Mora AM, Córdoba L, Cano JC, Hernandez-Bonilla D, Pardo L, Schnaas L, Smith DR, Menezes-Filho JA, Mergler D, Lindh CH, Eskenazi B, van Wendel de Joode B. Prenatal Mancozeb Exposure, Excess Manganese, and Neurodevelopment at 1 Year of Age in the Infants' Environmental Health (ISA) Study. ENVIRONMENTAL HEALTH PERSPECTIVES 2018; 126:057007. [PMID: 29847083 PMCID: PMC6072008 DOI: 10.1289/ehp1955] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 04/10/2018] [Accepted: 04/24/2018] [Indexed: 05/14/2023]
Abstract
BACKGROUND Although growing evidence suggests that early-life excess manganese (Mn) impairs neurodevelopment, data on the neurodevelopmental effects of mancozeb, a fungicide containing Mn, and its main metabolite ethylenethiourea (ETU) are limited. OBJECTIVE We examined whether prenatal mancozeb exposure and excess Mn were associated with neurodevelopment in 355 1-y-old infants living near banana plantations with frequent aerial mancozeb spraying in Costa Rica. METHODS We measured urinary ETU, hair Mn, and blood Mn concentrations in samples collected 1-3 times during pregnancy from mothers enrolled in the Infants' Environmental Health (ISA) study. We then assessed neurodevelopment in their 1-y-old infants using the Bayley Scales of Infant and Toddler Development, 3rd edition (BSID-III). We estimated exposure-outcome associations using linear regression models adjusted for maternal education, parity, gestational age at birth, child age, Home Observation for Measurement of the Environment score, and location of neurodevelopmental assessment. RESULTS Median (P25-P75) urinary ETU, hair Mn, and blood Mn measured during pregnancy were 3.3 μg/L (2.4-4.9; specific gravity-corrected), 1.7 μg/g (0.9-4.1), and 24.0 μg/L (20.3-28.0), respectively. Among girls, higher ETU was associated with lower social-emotional scores [β per 10-fold increase=-7.4 points (95% CI: -15.2, 0.4)], whereas higher hair Mn was associated with lower cognitive scores [-3.0 (-6.1, 0.1)]. Among boys, higher hair Mn was associated with lower social-emotional scores [-4.6 (-8.5, -0.8)]. We observed null associations for blood Mn, language, and motor outcomes. CONCLUSIONS Our findings indicate that maternal exposure to mancozeb and excess Mn during pregnancy may have adverse and sex-specific effects on infant neurodevelopment. https://doi.org/10.1289/EHP1955.
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Affiliation(s)
- Ana María Mora
- Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica
- Center for Environmental Research and Children’s Health (CERCH), School of Public Health, University of California at Berkeley, Berkeley, California, USA
| | - Leonel Córdoba
- Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica
| | - Juan Camilo Cano
- Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica
| | | | - Larissa Pardo
- Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica
| | - Lourdes Schnaas
- Division of Research in Community Interventions, National Institute of Perinatology, Mexico City, Mexico
| | - Donald R Smith
- Department of Microbiology and Environmental Toxicology, University of California at Santa Cruz, Santa Cruz, California, USA
| | | | - Donna Mergler
- Centre for Interdisciplinary Research Centre on Health, Well-being, Society and Environment (CINBIOSE), University of Quebec in Montreal, Montreal, Quebec, Canada
| | - Christian H Lindh
- Division of Occupational and Environmental Medicine, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Brenda Eskenazi
- Center for Environmental Research and Children’s Health (CERCH), School of Public Health, University of California at Berkeley, Berkeley, California, USA
| | - Berna van Wendel de Joode
- Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica
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Maisant SC, Villa AF, Poupon J, Langrand J, Garnier R. L’analyse isotopique du plomb : un outil utile en santé au travail en cas de multi-expositions. ARCH MAL PROF ENVIRO 2017. [DOI: 10.1016/j.admp.2016.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Jones AL. Emerging aspects of assessing lead poisoning in childhood. EMERGING HEALTH THREATS JOURNAL 2017. [DOI: 10.3402/ehtj.v2i0.7080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- AL Jones
- Discipline of Clinical Pharmacology and Clinical Toxicology, School of Medicine and Public Health and Calvary Mater Hospital, University of Newcastle, Callaghan, Australia
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Nussbaumer‐Streit B, Yeoh B, Griebler U, Pfadenhauer LM, Busert LK, Lhachimi SK, Lohner S, Gartlehner G. Household interventions for preventing domestic lead exposure in children. Cochrane Database Syst Rev 2016; 10:CD006047. [PMID: 27744650 PMCID: PMC6461195 DOI: 10.1002/14651858.cd006047.pub5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Lead poisoning is associated with physical, cognitive and neurobehavioural impairment in children, and trials have tested many household interventions to prevent lead exposure. This is an update of the original review, first published in 2008. OBJECTIVES To assess the effects of household interventions for preventing or reducing lead exposure in children, as measured by improvements in cognitive and neurobehavioural development, reductions in blood lead levels and reductions in household dust lead levels. SEARCH METHODS In May 2016 we searched CENTRAL, Ovid MEDLINE, Embase, nine other databases and two trials registers: the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov. We also checked the reference lists of relevant studies and contacted experts to find unpublished studies. SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs of household educational or environmental interventions, or combinations of interventions to prevent lead exposure in children (from birth to 18 years of age), where investigators reported at least one standardised outcome measure. DATA COLLECTION AND ANALYSIS Two authors independently reviewed all eligible studies for inclusion, assessed risk of bias and extracted data. We contacted trialists to obtain missing information. We assessed the quality of the evidence using the GRADE approach. MAIN RESULTS We included 14 studies involving 2643 children: 13 RCTs (involving 2565 children) and one quasi-RCT (involving 78 children). Children in all studies were under six years of age. Thirteen studies took place in urban areas of North America, and one was in Australia. Most studies were in areas with low socioeconomic status. Girls and boys were equally represented in all studies. The duration of the intervention ranged from 3 months to 24 months in 12 studies, while 2 studies performed interventions on a single occasion. Follow-up periods ranged from 6 months to 48 months. Three RCTs were at low risk of bias in all assessed domains. We rated two RCTs and one quasi-RCT as being at high risk of selection bias and six RCTs as being at high risk of attrition bias. For educational interventions, we rated the quality of evidence to be high for continuous blood lead levels and moderate for all other outcomes. For environmental interventions, we assessed the quality of evidence as moderate to low. National or international research grants or governments funded 12 studies, while the other 2 did not report their funding sources.No studies reported on cognitive or neurobehavioural outcomes. No studies reported on adverse events in children. All studies reported blood lead level outcomes.We put studies into subgroups according to their intervention type. We performed meta-analyses of both continuous and dichotomous data for subgroups where appropriate. Educational interventions were not effective in reducing blood lead levels (continuous: mean difference (MD) 0.02, 95% confidence interval (CI) -0.09 to 0.12, I² = 0%; 5 studies; N = 815; high quality evidence (log transformed); dichotomous ≥ 10.0 µg/dL (≥ 0.48 µmol/L): risk ratio (RR) 1.02, 95% CI 0.79 to 1.30; I² = 0%; 4 studies; N = 520; moderate quality evidence; dichotomous ≥ 15.0 µg/dL (≥ 0.72 µmol/L): RR 0.60, 95% CI 0.33 to 1.09; I² = 0%; 4 studies; N = 520; moderate quality evidence). Meta-analysis for the dust control subgroup also found no evidence of effectiveness on blood lead levels (continuous: MD -0.15, 95% CI -0.42 to 0.11; I² = 90%; 3 studies; N = 298; low quality evidence (log transformed); dichotomous ≥ 10.0 µg/dL (≥ 0.48 µmol/L): RR 0.93, 95% CI 0.73 to 1.18; I² = 0; 2 studies; N = 210; moderate quality evidence; dichotomous ≥ 15.0 µg/dL (≥ 0.72 µmol/L): RR 0.86, 95% CI 0.35 to 2.07; I² = 56%; 2 studies; N = 210; low quality evidence). After adjusting the dust control subgroup for clustering in meta-analysis, we found no evidence of effectiveness. We could not pool the studies using soil abatement (removal and replacement) and combination intervention groups in a meta-analysis due to substantial differences between studies, and generalisability or reproducibility of the results from these studies is unknown. Therefore, there is currently insufficient evidence to clarify whether soil abatement or a combination of interventions reduces blood lead levels. AUTHORS' CONCLUSIONS Based on current knowledge, household educational interventions are ineffective in reducing blood lead levels in children as a population health measure. Dust control interventions may lead to little or no difference in blood lead levels (the quality of evidence was moderate to low, meaning that future research is likely to change these results). There is currently insufficient evidence to draw conclusions about the effectiveness of soil abatement or combination interventions. No study reported on cognitive or neurobehavioural outcomes or adverse events. These patient-relevant outcomes would have been of great interest to draw conclusions for practice.Further trials are required to establish the most effective intervention for preventing lead exposure. Key elements of these trials should include strategies to reduce multiple sources of lead exposure simultaneously using empirical dust clearance levels. It is also necessary for trials to be carried out in low- and middle-income countries and in differing socioeconomic groups in high-income countries.
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Affiliation(s)
- Barbara Nussbaumer‐Streit
- Danube University KremsDepartment for Evidence‐based Medicine and Clinical EpidemiologyDr.‐Karl‐Dorrek‐Str. 30KremsAustria3500
- Danube University KremsCochrane AustriaDr.‐Karl‐Dorrek‐Str. 30KremsAustria3500
| | | | - Ursula Griebler
- Danube University KremsDepartment for Evidence‐based Medicine and Clinical EpidemiologyDr.‐Karl‐Dorrek‐Str. 30KremsAustria3500
- Danube University KremsCochrane AustriaDr.‐Karl‐Dorrek‐Str. 30KremsAustria3500
| | - Lisa M Pfadenhauer
- Ludwig‐Maximilians‐University MunichInstitute for Medical Informatics, Biometry and EpidemiologyMarchioninistr 13MunichBavariaGermany
| | - Laura K Busert
- Ludwig‐Maximilians‐University MunichInstitute for Medical Informatics, Biometry and EpidemiologyMarchioninistr 13MunichBavariaGermany
| | - Stefan K Lhachimi
- Leibniz Institute for Prevention Research and EpidemiologyResearch Group for Evidence‐Based Public HealthAchterstr. 30BremenGermany28359
- University of BremenInstitute for Public Health and Nursing Research, Health Sciences BremenBibliotheksstr. 1BremenGermany28359
| | | | - Gerald Gartlehner
- Danube University KremsDepartment for Evidence‐based Medicine and Clinical EpidemiologyDr.‐Karl‐Dorrek‐Str. 30KremsAustria3500
- Danube University KremsCochrane AustriaDr.‐Karl‐Dorrek‐Str. 30KremsAustria3500
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Pfadenhauer LM, Burns J, Rohwer A, Rehfuess EA. Effectiveness of interventions to reduce exposure to lead through consumer products and drinking water: A systematic review. ENVIRONMENTAL RESEARCH 2016; 147:525-36. [PMID: 26990846 DOI: 10.1016/j.envres.2016.03.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 05/19/2023]
Abstract
OBJECTIVES The objective of this systematic review is to assess the effectiveness of regulatory, environmental and educational interventions for reducing blood lead levels (BLLs) and associated health outcomes in children, pregnant women and the general population. METHODS Searches were run in MEDLINE, EMBASE and the Global Health Library up until August 2015. Studies were eligible for inclusion if they assessed the impact of regulatory, environmental or educational interventions, stand-alone or in combination, on BLLs among children, pregnant women or the general population through randomized controlled trials (RCT), controlled before-after (CBA), interrupted time series (ITS), uncontrolled before-after (UBA) or repeated cross-sectional studies. Studies assessing the impact of interventions to reduce exposure to lead in paint or household dust as well as studies concerned exclusively with environmental concentrations of lead were not included. As documented in a detailed protocol, screening, data extraction and quality appraisal were largely undertaken according to Cochrane standards. Harvest plots were used to graphically summarize evidence of effectiveness. RESULTS The searches yielded 6466 unique records, of which five met our eligibility criteria; two additional eligible studies were identified by experts. We did not find any studies regarding the effectiveness of regulatory, educational or environmental interventions targeting exposure to lead in consumer products. Evidence regarding the effectiveness of interventions in reducing BLLs from exposures through drinking water is limited in both quantity and quality. Stand-alone targeted educational interventions showed no statistically significant reductions in children's BLL (two RCT) when compared to general educational interventions. Likewise, instructing women to reduce or eliminate lead-contaminated drinking water showed no effect on BLL (one RCT). Stand-alone environmental interventions appeared more promising in reducing BLL (three UBA). Combining educational and environmental interventions and targeting multiple settings may be effective in reducing BLL, as suggested by one uncontrolled before-after study. No studies examining the effectiveness of regulatory interventions were found. CONCLUSIONS The limited quantity and quality of the evidence measuring BLL and associated health outcomes points to an urgent need for more robust research into the effectiveness of interventions to reduce lead exposure from consumer products and drinking water, especially for regulatory interventions.
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Affiliation(s)
- Lisa Maria Pfadenhauer
- Institute for Medical Informatics, Biometry and Epidemiology, University of Munich, Marchioninistrasse 15, 81377 Munich, Germany.
| | - Jacob Burns
- Institute for Medical Informatics, Biometry and Epidemiology, University of Munich, Marchioninistrasse 15, 81377 Munich, Germany
| | - Anke Rohwer
- Institute for Medical Informatics, Biometry and Epidemiology, University of Munich, Marchioninistrasse 15, 81377 Munich, Germany; Centre for Evidence-based Health Care, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl drive, Parow, 7500, South Africa
| | - Eva Annette Rehfuess
- Institute for Medical Informatics, Biometry and Epidemiology, University of Munich, Marchioninistrasse 15, 81377 Munich, Germany
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Finkelstein ME, Kuspa ZE, Welch A, Eng C, Clark M, Burnett J, Smith DR. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis. ENVIRONMENTAL RESEARCH 2014; 134:270-9. [PMID: 25173094 DOI: 10.1016/j.envres.2014.07.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 07/03/2014] [Accepted: 07/26/2014] [Indexed: 05/27/2023]
Abstract
Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events.
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Affiliation(s)
- Myra E Finkelstein
- Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064, USA.
| | - Zeka E Kuspa
- Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064, USA
| | - Alacia Welch
- National Park Service, Pinnacles National Park, 5000 Highway 146, Paicines, CA 95043, USA
| | - Curtis Eng
- Los Angeles Zoo and Botanical Gardens, 5333 Zoo Drive, Los Angeles, CA 90027, USA
| | - Michael Clark
- Los Angeles Zoo and Botanical Gardens, 5333 Zoo Drive, Los Angeles, CA 90027, USA
| | - Joseph Burnett
- Ventana Wildlife Society, 19045 Portola Dr. Ste. F-1, Salinas, CA 93908, USA
| | - Donald R Smith
- Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064, USA
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Kamenov GD, Gulson BL. The Pb isotopic record of historical to modern human lead exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 490:861-70. [PMID: 24907620 DOI: 10.1016/j.scitotenv.2014.05.085] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/13/2014] [Accepted: 05/19/2014] [Indexed: 05/13/2023]
Abstract
Human teeth and bones incorporate trace amounts of lead (Pb) from the local environment during growth and remodeling. Anthropogenic activities have caused changes in the natural Pb isotopic background since historical times and this is reflected in the Pb isotopes of historical European teeth. Lead mining and use increased exponentially during the last century and the isotopic compositions of modern human teeth reflect the modern anthropogenic Pb. USA teeth show the most radiogenic Pb and Australian teeth show the least radiogenic Pb, a result of different Pb ores used in the two regions. During the last century the Australian Pb was exported to Europe, Asia, South America, and Africa, resulting in swamping of the local environmental Pb signal by the imported Pb. As a result, the modern human teeth in Europe show a significant drop to lower isotopic values compared with historical times. Similarly, modern human teeth in other regions of the world show similar Pb isotopic ratios to modern European teeth reflecting the Pb imports. The specific pattern of human Pb exposure allows us to use the Pb isotopic signal recorded in the skeleton as a geo-referencing tool. As historical European teeth show a distinct Pb signal, we can identify early European skeletal remains in the New World and likely elsewhere. In modern forensic investigations we can discriminate to some extent Eastern Europeans from Western and Northern Europeans. Australians can be identified to some extent in any region in the world, although there is some overlap with Western European individuals. Lead isotopes can be used to easily identify foreigners in the USA, as modern USA teeth are distinct from any other region of the world. By analogy, USA individuals can be identified virtually in any other region of the world.
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Affiliation(s)
- George D Kamenov
- Department of Geological Sciences, University of Florida, 241 Williamson Hall, Gainesville, FL 32611, USA.
| | - Brian L Gulson
- Graduate School of the Environment, Faculty of Science, Macquarie University, Sydney, NSW 2109, Australia
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Medical toxicology case presentations: to chelate or not to chelate, is that the question? J Med Toxicol 2014; 9:373-9. [PMID: 24243289 DOI: 10.1007/s13181-013-0338-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Four case studies described in this article were presented to a panel of physicians participating in the ACMT "Use and Misuse of Metal Chelation Therapy" Symposium in February 2012. The individuals who participated in the panel are listed in the appendix. These cases highlight some of the practical questions facing medical providers when issues of metal toxicity and its treatment arise. Medical toxicologists are valuable resources for information, public debate, consultation, and treatment of patients with concerns about heavy metal exposure.
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Franck U, Leitte AM, Suppan P. Multiple exposures to airborne pollutants and hospital admissions due to diseases of the circulatory system in Santiago de Chile. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 468-469:746-56. [PMID: 24064344 DOI: 10.1016/j.scitotenv.2013.08.088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/23/2013] [Accepted: 08/27/2013] [Indexed: 05/27/2023]
Abstract
BACKGROUND High concentrations of various air pollutants have been associated with hospitalization due to development and exacerbation of cardiovascular diseases. OBJECTIVES We aimed to assess associations between airborne exposures by particulate matter as well as gaseous air pollutants and hospital admissions due to different cardiovascular disease groups in Santiago de Chile. METHODS The study was performed in the metropolitan area of Santiago de Chile during 2004-2007. We applied a time-stratified case-crossover analysis taking temporal variation, meteorological conditions and autocorrelation into account. We computed associations between daily ambient concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), particulate matter (PM10 and PM2.5--particulate matter with aerodynamic diameters less than 10 or 2.5 μm, respectively) or ozone (O3) and hospital admissions for cardiovascular illnesses. RESULTS We found for CO, NO2, PM10 and PM2.5 adverse relationships to cardiovascular admissions while effect strength and lag depended on the pollutant and on the disease group. By trend, in 1-pollutant models most adverse pollutants were NO2 and particulate matter (PM10 and PM2.5) followed by CO, while in 2-pollutant models effects of PM10 persisted in most cases whereas other effects weakened. In addition the strongest effects seemed to be immediate or with a delay of up to 2 days. Adverse effects of ozone could not be detected. CONCLUSIONS Our results provided evidence for adverse health effects of combined exposure to airborne pollutants. Different pollutants accounted for varying adverse effects within different cardiovascular disease groups. Taking case numbers and effect strength of all cardiovascular diseases into account, mitigation measures should address all pollutants but especially NO2, PM10, and CO.
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Affiliation(s)
- Ulrich Franck
- Core Facility Studies, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.
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Scinicariello F, Buser MC, Mevissen M, Portier CJ. Blood lead level association with lower body weight in NHANES 1999-2006. Toxicol Appl Pharmacol 2013; 273:516-23. [PMID: 24099784 DOI: 10.1016/j.taap.2013.09.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/16/2013] [Accepted: 09/23/2013] [Indexed: 01/22/2023]
Abstract
BACKGROUND Lead exposure is associated with low birth-weight. The objective of this study is to determine whether lead exposure is associated with lower body weight in children, adolescents and adults. METHODS We analyzed data from NHANES 1999-2006 for participants aged ≥3 using multiple logistic and multivariate linear regression. Using age- and sex-standardized BMI Z-scores, overweight and obese children (ages 3-19) were classified by BMI ≥85 th and ≥95 th percentiles, respectively. The adult population (age ≥20) was classified as overweight and obese with BMI measures of 25-29.9 and ≥30, respectively. Blood lead level (BLL) was categorized by weighted quartiles. RESULTS Multivariate linear regressions revealed a lower BMI Z-score in children and adolescents when the highest lead quartile was compared to the lowest lead quartile (β (SE)=-0.33 (0.07), p<0.001), and a decreased BMI in adults (β (SE)=-2.58 (0.25), p<0.001). Multiple logistic analyses in children and adolescents found a negative association between BLL and the percentage of obese and overweight with BLL in the highest quartile compared to the lowest quartile (OR=0.42, 95% CI: 0.30-0.59; and OR=0.67, 95% CI: 0.52-0.88, respectively). Adults in the highest lead quartile were less likely to be obese (OR=0.42, 95% CI: 0.35-0.50) compared to those in the lowest lead quartile. Further analyses with blood lead as restricted cubic splines, confirmed the dose-relationship between blood lead and body weight outcomes. CONCLUSIONS BLLs are associated with lower body mass index and obesity in children, adolescents and adults.
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Affiliation(s)
- Franco Scinicariello
- Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA 30341, USA.
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Housing interventions and control of health-related chemical agents: a review of the evidence. JOURNAL OF PUBLIC HEALTH MANAGEMENT AND PRACTICE 2012; 16:S24-33. [PMID: 20689371 DOI: 10.1097/phh.0b013e3181e3cc2a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Subject matter experts systematically reviewed evidence on the effectiveness of housing interventions that affect health outcomes associated with exposure to chemical agents, such as pesticides, lead, volatile organic compounds, as well as the radon gas. Particulates were also examined, and the role of ventilation on exposures was assessed. The review included both published literature and peer-reviewed reports from the US Environmental Protection Agency. Four of the 14 interventions reviewed had sufficient evidence to demonstrate their effectiveness and are ready for implementation: radon air mitigation by using active soil depressurization systems, integrated pest management to reduce exposures to pesticides, smoke-free home policies making indoor areas smoke-free (ie, no smoking allowed anywhere at any time), and residential lead hazard control. Four interventions needed more field evaluation, 3 needed formative research, and 3 either had no sufficient evidence of effectiveness or had evidence the interventions were ineffective. This evidence review shows that housing improvements are likely to help reduce radon-induced lung cancer, cardiovascular mortality related to secondhand smoke, and neurological effects from exposure to pesticides and lead paint. Investing in housing interventions may yield important savings from reduced disease and injury from avoidable exposures to chemical agents.
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Isotopic analyses by ICP-MS in clinical samples. Anal Bioanal Chem 2012; 405:2785-97. [DOI: 10.1007/s00216-012-6457-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/24/2012] [Accepted: 09/25/2012] [Indexed: 11/26/2022]
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Recio-Vega R, Valdez-Abrego C, Adame-Lopez B, Gurrola-Mendez A. Surveillance of elevated blood lead levels in children in Torreon, Coahuila, Mexico, 1998–2010. Int J Hyg Environ Health 2012; 215:507-13. [DOI: 10.1016/j.ijheh.2011.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 10/05/2011] [Accepted: 10/21/2011] [Indexed: 11/27/2022]
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Lead poisoning and the deceptive recovery of the critically endangered California condor. Proc Natl Acad Sci U S A 2012; 109:11449-54. [PMID: 22733770 DOI: 10.1073/pnas.1203141109] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Endangered species recovery programs seek to restore populations to self-sustaining levels. Nonetheless, many recovering species require continuing management to compensate for persistent threats in their environment. Judging true recovery in the face of this management is often difficult, impeding thorough analysis of the success of conservation programs. We illustrate these challenges with a multidisciplinary study of one of the world's rarest birds-the California condor (Gymnogyps californianus). California condors were brought to the brink of extinction, in part, because of lead poisoning, and lead poisoning remains a significant threat today. We evaluated individual lead-related health effects, the efficacy of current efforts to prevent lead-caused deaths, and the consequences of any reduction in currently intensive management actions. Our results show that condors in California remain chronically exposed to harmful levels of lead; 30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects, measured as >60% inhibition of the heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ∼20% of free-flying birds have blood lead levels (≥450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality. Lead isotopic analysis shows that lead-based ammunition is the principle source of lead poisoning in condors. Finally, population models based on condor demographic data show that the condor's apparent recovery is solely because of intensive ongoing management, with the only hope of achieving true recovery dependent on the elimination or substantial reduction of lead poisoning rates.
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Rogers TA, Bedrosian B, Graham J, Foresman KR. Lead exposure in large carnivores in the greater Yellowstone ecosystem. J Wildl Manage 2011. [DOI: 10.1002/jwmg.277] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Nie LH, Wright RO, Bellinger DC, Hussain J, Amarasiriwardena C, Chettle DR, Pejović-Milić A, Woolf A, Shannon M. Blood lead levels and cumulative blood lead index (CBLI) as predictors of late neurodevelopment in lead poisoned children. Biomarkers 2011; 16:517-24. [PMID: 21827276 DOI: 10.3109/1354750x.2011.604133] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To find the best lead exposure assessment marker for children. METHODS We recruited 11 children, calculated a cumulative blood lead index (CBLI) for the children, measured their concurrent BLL, assessed their development, and measured their bone lead level. RESULTS Nine of 11 children had clinically significant neurodevelopment problems. CBLI and current blood lead level, but not the peak lead level, were significantly or marginally negatively associated with the full-scale IQ score. CONCLUSION Lead exposure at younger age significantly impacts a child's later neurodevelopment. CBLI may be a better predictor of neurodevelopment than are current or peak blood lead levels.
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Affiliation(s)
- Linda H Nie
- Purdue University, School of Health Sciences, West Lafayette, IN, USA.
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Graber LK, Asher D, Anandaraja N, Bopp RF, Merrill K, Cullen MR, Luboga S, Trasande L. Childhood lead exposure after the phaseout of leaded gasoline: an ecological study of school-age children in Kampala, Uganda. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:884-9. [PMID: 20194080 PMCID: PMC2898868 DOI: 10.1289/ehp.0901768] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 03/01/2010] [Indexed: 05/02/2023]
Abstract
BACKGROUND Tetraethyl lead was phased out of gasoline in Uganda in 2005. Recent mitigation of an important source of lead exposure suggests examination and re-evaluation of the prevalence of childhood lead poisoning in this country. Ongoing concerns persist about exposure from the Kiteezi landfill in Kampala, the country's capital. OBJECTIVES We determined blood lead distributions among Kampala schoolchildren and identified risk factors for elevated blood lead levels (EBLLs; >or= 10 microg/dL). Analytical approach: Using a stratified, cross-sectional design, we obtained blood samples, questionnaire data, and soil and dust samples from the homes and schools of 163 4- to 8-year-old children representing communities with different risks of exposure. RESULTS The mean blood lead level (BLL) was 7.15 microg/dL; 20.5% of the children were found to have EBLL. Multivariable analysis found participants whose families owned fewer household items, ate canned food, or used the community water supply as their primary water source to have higher BLLs and likelihood of EBLLs. Distance < 0.5 mi from the landfill was the factor most strongly associated with increments in BLL (5.51 microg/dL, p < 0.0001) and likelihood of EBLL (OR = 4.71, p = 0.0093). Dust/soil lead was not significantly predictive of BLL/EBLL. CONCLUSIONS Lead poisoning remains highly prevalent among school-age children in Kampala. Confirmatory studies are needed, but further efforts are indicated to limit lead exposure from the landfill, whether through water contamination or through another mechanism. Although African nations are to be lauded for the removal of lead from gasoline, this study serves as a reminder that other sources of exposure to this potent neurotoxicant merit ongoing attention.
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Affiliation(s)
| | | | - Natasha Anandaraja
- Global Health Center and
- Department of Pediatrics, Mount Sinai School of Medicine, New York, New York, USA
| | - Richard F. Bopp
- Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Karen Merrill
- Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Mark R. Cullen
- Department of Medicine, Stanford University Medical Center, Palo Alto, California, USA
| | - Samuel Luboga
- Makerere University School of Medicine, Kampala, Uganda
| | - Leonardo Trasande
- Department of Pediatrics, Mount Sinai School of Medicine, New York, New York, USA
- Department of Preventive Medicine, Mount Sinai School of Medicine, New York, New York, USA
- Address correspondence to L. Trasande, Department of Preventive Medicine, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1057, New York, NY 10029 USA. Telephone: (212) 824-7023. Fax: (212) 996-0407. E-mail:
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Finkelstein ME, George D, Scherbinski S, Gwiazda R, Johnson M, Burnett J, Brandt J, Lawrey S, Pessier AP, Clark M, Wynne J, Grantham J, Smith DR. Feather lead concentrations and (207)Pb/(206)Pb ratios reveal lead exposure history of California Condors (Gymnogyps californianus). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:2639-2647. [PMID: 20199067 DOI: 10.1021/es903176w] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
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.
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Affiliation(s)
- M E Finkelstein
- Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, California 95064, USA.
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Scinicariello F, Yesupriya A, Chang MH, Fowler BA. Modification by ALAD of the association between blood lead and blood pressure in the U.S. population: results from the Third National Health and Nutrition Examination Survey. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:259-64. [PMID: 20123609 PMCID: PMC2831927 DOI: 10.1289/ehp.0900866] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 10/07/2009] [Indexed: 05/04/2023]
Abstract
BACKGROUND Environmental lead exposure has been found to be associated with an increased risk of hypertension. Individuals vary greatly in susceptibility to lead toxicity, and genetic susceptibility has often been cited as the probable cause for such variation. OBJECTIVE The main objective is to determine the role of the aminolevulinic acid dehydratase (ALAD) gene, which encodes the main carrier protein of lead in blood, in the association between lead exposure and blood pressure (BP) and hypertension in the U.S. population. METHODS We analyzed data from individuals >or= 17 years of age who participated in the Third National Health and Nutrition Examination Survey for whom DNA was available (n = 6,016). Multivariable logistic and linear regressions stratified by race/ethnicity were used to examine whether hypertension and BP were associated with ALAD and blood lead levels (BLL). RESULTS BLL was associated with systolic BP in non-Hispanic whites and with hypertension and systolic and diastolic BP in non-Hispanic blacks. BLL was not associated with BP outcomes in Mexican Americans. Non-Hispanic white ALAD2 carriers in the highest BLL quartile (3.852.9 microg/dL) had a significantly higher adjusted prevalence odds ratio for hypertension compared with ALAD1 homozygous individuals. We also found a significant interaction between lead concentration and the ALAD2 allele in non-Hispanic whites and non-Hispanic blacks in relation to systolic BP. CONCLUSIONS BLL may be an important risk factor for hypertension and increased systolic and diastolic BP. These associations may be modified by ALAD genotype.
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Affiliation(s)
- Franco Scinicariello
- Division of Toxicology and Environmental Medicine, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia 30341, USA.
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Brown MJ, McWeeney G, Kim R, Tahirukaj A, Bulat P, Syla S, Savic Z, Amitai Y, Dignam T, Kaluski DN. Lead poisoning among internally displaced Roma, Ashkali and Egyptian children in the United Nations-Administered Province of Kosovo. Eur J Public Health 2009; 20:288-92. [PMID: 19897587 DOI: 10.1093/eurpub/ckp164] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND This study assessed the association between lead poisoning prevention activities and blood lead levels (BLLs) among children living in lead-contaminated camps for internally displaced persons in the United Nations-Administered Province of Kosovo. METHODS We conducted a population-based study to examine the relationship among geometric mean BLLs in children (i) born before any lead poisoning prevention activities were instituted, (ii) born when specific interim interventions were instituted and (iii) born after relocation and medical therapy were available. The study population consisted of 145 of the 186 children born in the camps between December 1999 and July 2007. RESULTS Lower mean BLLs were found in children born following implementation of the interventions as compared with the children born before the interventions. However, this decrease in mean BLLs was attenuated in children born into families suspected of informal lead smelting. CONCLUSION Despite lower BLLs following interventions, children living in these camps have BLLs that remain unacceptably high. Further efforts are urgently needed to control or eliminate lead exposure in this population. Continued blood lead monitoring of the population is also warranted.
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Affiliation(s)
- Mary Jean Brown
- Lead Poisoning Prevention Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30348, USA.
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Lucchini R, Zimmerman N. Lifetime cumulative exposure as a threat for neurodegeneration: need for prevention strategies on a global scale. Neurotoxicology 2009; 30:1144-8. [PMID: 19835910 DOI: 10.1016/j.neuro.2009.10.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 06/29/2009] [Accepted: 10/05/2009] [Indexed: 11/18/2022]
Abstract
Exposure to neurotoxic agents represents a concern of high priority in modern society. The nervous system can compensate for the toxic effects caused by low doses, but prolonged and lifetime exposure can also lead to delayed neurodegenerative effects for very low levels. The reported frequency of neurodegenerative diseases is constantly increasing, resulting in serious negative impacts on the health of the worldwide population. Future estimates indicate that Parkinson's Disease will increase mostly in industrialized countries during the next few years. Exposure to neurotoxic agents can take place during the various phases of life, beginning from the embryonic stage. The time variable plays an important role in neurotoxicity, both in terms of exposure duration and the period of life when it occurs. Prevention and the standards necessary to achieve it are needed to avoid health effects due to lifetime exposure. Risk assessment is a fundamental requirement for risk management and related preventive policies. Therefore, the relationship between exposure and effects should consider measures of cumulative exposure, to integrate both the historical exposure and the exposure to mixed agents, and the related cumulative effects. Examples and suggestions of different metrics for lifetime and cumulative exposure are illustrated in this paper, which reflects a summary of the key note lecture presented at the 10th International Symposium on Neurobehavioral Methods and Effects in Occupational and Environmental Health of the International Commission on Occupational Health.
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Affiliation(s)
- Roberto Lucchini
- Department of Experimental and Applied Medicine, Section of Occupational Health, University of Brescia, P.le Spedali Civili 1, 25123 Brescia, Italy.
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Bone lead and endogenous exposure in an environmentally exposed elderly population: the normative aging study. J Occup Environ Med 2009; 51:848-57. [PMID: 19528829 DOI: 10.1097/jom.0b013e3181aa0106] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The objective of this study is to investigate the mobilization of lead from bone to blood (endogenous exposure) in a large epidemiologic population. METHODS Study subjects were 776 participants in the Normative Aging Study. The subjects had their tibia lead, patella lead, blood lead, and urinary N-telopeptide (NTx) levels measured 1 to 4 times from 1991 to 2002. Regression models were estimated to quantify the association between tibia and patella lead and blood lead. We studied nonlinearity of the association, and explored possible factors that may modify it, including age and NTx levels. RESULTS AND CONCLUSIONS There is significant association between bone lead and blood lead, and the association is nonlinear. The nonlinear associations between blood lead and bone lead are not significantly modified by age and NTx.
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Jones A. Emerging aspects of assessing lead poisoning in childhood. EMERGING HEALTH THREATS JOURNAL 2009; 2:e3. [PMID: 22460284 PMCID: PMC3167648 DOI: 10.3134/ehtj.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/10/2008] [Revised: 12/14/2008] [Accepted: 01/22/2009] [Indexed: 11/18/2022]
Abstract
This review covers the epidemiology of lead poisoning in children on a global scale. Newer sources of lead poisoning are identified. The methods that are used to assess a population of children exposed to lead are discussed, together with the ways of undertaking an exposure risk assessment; this includes assessing the time course and identifying sources of lead exposure. Human assessment measures for lead toxicity, such as blood lead concentrations, deciduous tooth lead, and use of zinc protoporphyrin estimations are evaluated. The role of isotopic fingerprinting techniques for identifying environmental sources of exposure is discussed. Among emerging data on the cognitive and behavioral effects of lead on children, the review considers the growing evidence of neurocognitive dysfunction with blood lead concentrations even below 10 µg/dl. The challenge of assessing and explaining the risk that applies to an individual as opposed to a population is discussed. Intervention strategies to mitigate risk from lead are examined together with the limited role for and limitations of chelation therapy for lead. Lessons learned from managing a population lead-dust exposure event in Esperance, Western Australia in 2007 are discussed throughout the review.
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Affiliation(s)
- Al Jones
- Discipline of Clinical Pharmacology and Clinical Toxicology, School of Medicine and Public Health and Calvary Mater Hospital, University of Newcastle, Callaghan, Australia
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Sanders T, Liu Y, Buchner V, Tchounwou PB. Neurotoxic effects and biomarkers of lead exposure: a review. REVIEWS ON ENVIRONMENTAL HEALTH 2009; 24:15-45. [PMID: 19476290 PMCID: PMC2858639 DOI: 10.1515/reveh.2009.24.1.15] [Citation(s) in RCA: 472] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Lead, a systemic toxicant affecting virtually every organ system, primarily affects the central nervous system, particularly the developing brain. Consequently, children are at a greater risk than adults of suffering from the neurotoxic effects of lead. To date, no safe lead-exposure threshold has been identified. The ability of lead to pass through the blood-brain barrier is due in large part to its ability to substitute for calcium ions. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurologic disorders. At the molecular level, lead interferes with the regulatory action of calcium on cell functions and disrupts many intracellular biological activities. Experimental studies have also shown that lead exposure may have genotoxic effects, especially in the brain, bone marrow, liver, and lung cells. Knowledge of the neurotoxicology of lead has advanced in recent decades due to new information on its toxic mechanisms and cellular specificity. This paper presents an overview, updated to January 2009, of the neurotoxic effects of lead with regard to children, adults, and experimental animals at both cellular and molecular levels, and discusses the biomarkers of lead exposure that are useful for risk assessment in the field of environmental health.
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Affiliation(s)
- Talia Sanders
- Molecular Toxicology Research Laboratory, NIH RCMI - Center for Environmental Health, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, USA
| | - Yiming Liu
- Molecular Toxicology Research Laboratory, NIH RCMI - Center for Environmental Health, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, USA
| | | | - Paul B. Tchounwou
- Molecular Toxicology Research Laboratory, NIH RCMI - Center for Environmental Health, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, USA
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Gulson B. Stable lead isotopes in environmental health with emphasis on human investigations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 400:75-92. [PMID: 18718638 DOI: 10.1016/j.scitotenv.2008.06.059] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 06/30/2008] [Accepted: 06/30/2008] [Indexed: 05/26/2023]
Abstract
There has been widespread use of stable lead isotopes in the earth sciences for more than 40 years focussed on the origin and age of rocks and minerals with lesser application in environmental investigations where the emphasis has been directed typically to the source of lead in environmental media such as air, water and soils. In contrast, the number of environmental health investigations focussed on humans (and primates) is limited in spite of the demonstrated utility of the approach in pioneering studies in the early 1970's. This paper reviews the status of lead isotopes in human investigations especially over the past 2 decades, the period over which most activity has taken place. Following a brief introduction to the method, examples are provided illustrating the use of lead isotopes in a wide spectrum of activities including sources and pathways of lead in diverse environments from urban to mining communities, various applications associated with pregnancy, the contribution of bone lead to blood lead including in the elderly, the half-life of lead in blood, and lead in bones and other media. A brief outline of critical research on non-human primates is also given. The lead isotope method is a powerful technique for tracing lead and could be employed more widely in human investigations.
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Affiliation(s)
- Brian Gulson
- Graduate School of the Environment, Macquarie University, Sydney NSW, Australia.
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Smith D, Gwiazda R, Bowler R, Roels H, Park R, Taicher C, Lucchini R. Biomarkers of Mn exposure in humans. Am J Ind Med 2007; 50:801-11. [PMID: 17924418 DOI: 10.1002/ajim.20506] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Studies have reported associations between manganese (Mn) exposures and Mn levels in blood and urine, though the suitability of these biological measures as biomarkers of exposure is not well known. METHODS We evaluated whether whole blood, plasma, and urine Mn levels reflect exposures in occupationally exposed humans. RESULTS In active ferroalloy workers, blood Mn was associated with total air Mn levels in subjects currently exposed to low (median = 0.42 microg/m(3), P = 0.009) and moderate (median = 4.2 microg/m(3), P = 0.007) air Mn levels, but not in workers exposed to the highest Mn levels (median = 292 microg/m(3), P = 0.31). In bridge welders blood Mn (P < 0.01), but not plasma or urine Mn was significantly associated with their cumulative respiratory exposure index. In welders, approximately 6% (range approximately 3-9%) of whole blood Mn was contained in the plasma fraction, though there was no association between whole blood and plasma Mn levels (Pearson's R = 0.258, P = 0.12). In contrast, in fresh whole blood samples spiked with Mn ex vivo approximately 80% or more of added Mn partitioned in the plasma, while only approximately 20% or less partitioned in the cellular fraction. CONCLUSIONS These data suggest a complex and limited relationship between exposure and blood Mn levels that may depend upon exposure attributes and the latency of blood sampling relative to exposure; plasma and urine Mn appear to be of little utility as exposure biomarkers. This underscores the need to fully characterize and validate these or other biomarkers for use in constructing appropriate exposure metrics and determining exposure-effect relationships.
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Affiliation(s)
- Donald Smith
- Environmental Toxicology, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA, USA.
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40
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Kamenov GD. High-precision Pb isotopic measurements of teeth and environmental samples from Sofia (Bulgaria): insights for regional lead sources and possible pathways to the human body. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/s00254-007-1017-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Krachler M. Environmental applications of single collector high resolution ICP-MS. ACTA ACUST UNITED AC 2007; 9:790-804. [PMID: 17671659 DOI: 10.1039/b703823m] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The number of environmental applications of single collector high resolution ICP-MS (HR-ICP-MS) has increased rapidly in recent years. There are many factors that contribute to make HR-ICP-MS a very powerful tool in environmental analysis. They include the extremely low detection limits achievable, tremendously high sensitivity, the ability to separate ICP-MS signals of the analyte from spectral interferences, enabling the reliable determination of many trace elements, and the reasonable precision of isotope ratio measurements. These assets are improved even further using high efficiency sample introduction systems. Therefore, external factors such as the stability of laboratory blanks are frequently the limiting factor in HR-ICP-MS analysis rather than the detection power. This review aims to highlight the most recent applications of HR-ICP-MS in this sector, focusing on matrices and applications where the superior capabilities of the instrumental technique are most useful and often ultimately required.
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Affiliation(s)
- Michael Krachler
- Institute of Environmental Geochemistry, University of Heidelberg, Im Neuenheimer Feld 236, 69120, Heidelberg, Germany.
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Church ME, Gwiazda R, Risebrough RW, Sorenson K, Chamberlain CP, Farry S, Heinrich W, Rideout BA, Smith DR. Ammunition is the principal source of lead accumulated by California condors re-introduced to the wild. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2006; 40:6143-50. [PMID: 17051813 DOI: 10.1021/es060765s] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The endangered California Condor (Gymnogyps californianus) was reduced to a total population of 22 birds by the end of 1982. Their captive-bred descendants are now being released back into the wild in California, Arizona, and Baja California, where monitoring indicates they may accumulate lead to toxic levels. Fragments of ammunition in the carcasses of game animals such as deer, elk, and feral pigs not retrieved by hunters or in gut piles left in the field have been considered a plausible source of the lead, though little direct evidence is available to support this hypothesis. Here, we measured lead concentrations and isotope ratios in blood from 18 condors living in the wild in central California, in 8 pre-release birds, and in diet and ammunition samples to determine the importance of ammunition as a source of exposure. Blood lead levels in pre-release condors were low (average 27.7 ng/mL, SD 4.9 ng/ mL) and isotopically similar to dietary and background environmental lead in California. In contrast, blood lead levels in free-flying condors were substantially higher (average 246 ng/mL, SD 229 ng/mL) with lead isotopic compositions that approached or matched those of the lead ammunition. A two-endmember mixing model defined by the background 207Pb/206Pb ratio of representative condor diet samples (0.8346) and the upper 207Pb/206Pb ratio of the ammunition samples (0.8184) was able to account for the blood lead isotopic compositions in 20 out of the 26 live condors sampled in this study (i.e., 77%). Finally, lead in tissues and in a serially sampled growing feather recovered postmortem from a lead-poisoned condor in Arizona evidence acute exposure from an isotopically distinct lead source. Together, these data indicate that incidental ingestion of ammunition in carcasses of animals killed by hunters is the principal source of elevated lead exposure that threatens the recovery in the wild of this endangered species.
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Affiliation(s)
- Molly E Church
- Department of Environmental Toxicology, University of California, Santa Cruz 95064, USA
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Barbosa F, Ramires I, Rodrigues MHC, Saint' Pierre TD, Curtius AJ, Buzalaf MR, Gerlach RF, Tanus-Santos JE. Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. ENVIRONMENTAL RESEARCH 2006; 102:90-5. [PMID: 16678152 DOI: 10.1016/j.envres.2006.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Revised: 03/16/2006] [Accepted: 03/21/2006] [Indexed: 05/09/2023]
Abstract
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.
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Affiliation(s)
- Fernando Barbosa
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto-FCFRP-USP, Ave do café, s/n, Monte Alegre, 14040-903 Ribeirão Preto, SP, Brazil.
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Barbosa Jr F, Tanus-Santos JE, Gerlach RF, Parsons PJ. A critical review of biomarkers used for monitoring human exposure to lead: advantages, limitations and future needs. CIENCIA & SAUDE COLETIVA 2006. [DOI: 10.1590/s1413-81232006000100032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lead concentration in whole blood (Blood-Pb) is the primary biomarker used to monitor exposure to this metallic element. However, the difficulty in assessing the exact nature of Pb exposure is dependent not so much on problems with current analytical methodologies, but rather on the complex toxicokinetics of Pb within various body compartments. If we are to differentiate more effectively between Pb that is stored in the body for years and Pb from recent exposure, information on other biomarkers of exposure may be needed. None of the current biomarkers of internal Pb dose has yet been accepted by the scientific community as a reliable substitute for a Blood-Pb measurement. This review focuses on the limitations of biomarkers of Pb exposure, and the need to improve the accuracy of their measurement. We present here only the traditional analytical protocols in current use and we attempt to assess the influence of confounding variables on Blood-Pb levels. Finally, we discuss the interpretation of Blood-Pb data with respect to both external and endogenous Pb exposure, past or recent exposure, as well as the significance of lead determinations in human specimens including hair, nails, saliva, bone, blood, urine, feces, and exfoliated teeth.
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Brown MJ, McLaine P, Dixon S, Simon P. A randomized, community-based trial of home visiting to reduce blood lead levels in children. Pediatrics 2006; 117:147-53. [PMID: 16396872 DOI: 10.1542/peds.2004-2880] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The objective of this study was to measure the effectiveness of intensive case management to reduce blood lead levels (BLLs) in children. Lead poisoning remains a common, preventable pediatric condition despite advances in reducing children's BLLs in the United States. Substantial evidence implicates lead paint-contaminated house dust as the most common high-dose source of lead in children's environments. Housekeeping and parental supervision also may contribute to risk for lead exposure. METHODS We conducted a community-based, randomized trial of comprehensive education and home visiting for families of children with BLLs 15 to 19 microg/dL. BLLs after 1 year of follow-up were compared for intervention group children, whose families received individualized education that was designed to address specific risks factors in a child's environment, and comparison group children, whose families received customary care, usually 1 or 2 educational visits. Environmental samples were collected at baseline and after 1 year of follow-up for intervention group children and compared with those of comparison group children, collected only at the end of study. RESULTS During the follow-up period, parents of intervention group children (n = 92) successfully decreased dust lead levels and significantly improved parent-child interaction and family housekeeping practices compared with comparison group children (n = 83). Overall geometric mean BLLs declined by 47%, and the difference in BLL by group was not significant (9 vs 8.3 microg/dL for intervention versus comparison group children, respectively.) After 1 year, nearly half of enrolled children had BLLs > or = 10 microg/dL. CONCLUSIONS Until a reservoir of lead-safe housing is created, programs that educate families to reduce environmental exposure are needed. Although providing families with quantitative information regarding lead contamination may have a role in short-term efforts to prevent lead exposure, these null findings suggest that it has little benefit once BLLs are elevated.
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Affiliation(s)
- Mary Jean Brown
- Lead Poisoning Prevention Branch, Division of Emergency and Environmental Health Services, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
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Barbosa F, Tanus-Santos JE, Gerlach RF, Parsons PJ. A critical review of biomarkers used for monitoring human exposure to lead: advantages, limitations, and future needs. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:1669-74. [PMID: 16330345 PMCID: PMC1314903 DOI: 10.1289/ehp.7917] [Citation(s) in RCA: 461] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Lead concentration in whole blood (BPb) is the primary biomarker used to monitor exposure to this metallic element. The U.S. Centers for Disease Control and Prevention and the World Health Organization define a BPb of 10 microg/dL (0.48 micromol/L) as the threshold of concern in young children. However, recent studies have reported the possibility of adverse health effects, including intellectual impairment in young children, at BPb levels < 10 microg/dL, suggesting that there is no safe level of exposure. It appears impossible to differentiate between low-level chronic Pb exposure and a high-level short Pb exposure based on a single BPb measurement; therefore, serial BPb measurements offer a better estimation of possible health outcomes. The difficulty in assessing the exact nature of Pb exposure is dependent not so much on problems with current analytical methodologies, but rather on the complex toxicokinetics of Pb within various body compartments (i.e., cycling of Pb between bone, blood, and soft tissues). If we are to differentiate more effectively between Pb stored in the body for years and Pb from recent exposure, information on other biomarkers of exposure may be needed. None of the current biomarkers of internal Pb dose have yet been accepted by the scientific community as a reliable substitute for a BPb measurement. This review focuses on the limitations of biomarkers of Pb exposure and the need to improve the accuracy of their measurement. We present here only the traditional analytical protocols in current use, and we attempt to assess the influence of confounding variables on BPb levels. Finally, we discuss the interpretation of BPb data with respect to both external and endogenous Pb exposure, past or recent exposure, as well as the significance of Pb determinations in human specimens including hair, nails, saliva, bone, blood (plasma, whole blood), urine, feces, and exfoliated teeth.
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Affiliation(s)
- Fernando Barbosa
- Department of Pharmacology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
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