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Klus JK, Thurston SW, Myers GJ, Watson GE, Rand MD, Love TM, Yeates AJ, Mulhern MS, McSorley EM, Strain JJ, Shamlaye CF, van Wijngaarden E. Postnatal methylmercury exposure and neurodevelopmental outcomes at 7 years of age in the Seychelles Child Development Study Nutrition Cohort 2. Neurotoxicology 2023; 99:115-119. [PMID: 37832849 PMCID: PMC10842381 DOI: 10.1016/j.neuro.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023]
Abstract
BACKGROUND Consumption of fish yields many nutritional benefits, but also results in exposure to methylmercury (MeHg). The developing brain is known to be particularly susceptible to MeHg toxicity in high doses. However, the potential impact of low-level environmental exposure from fish consumption on children's neurodevelopment remains unclear. METHODS We investigated postnatal MeHg exposure at 7 years and its association with a battery of 17 neurodevelopmental outcomes in a subset of children (n = 376) from 1535 enrolled mother-child pairs in Nutrition Cohort 2 of the Seychelles Child Development Study (SCDS NC2). Each outcome was modeled in relation to postnatal MeHg exposure using linear regression, adjusting for prenatal MeHg exposure, levels of maternal polyunsaturated fatty acids (PUFA), and several other covariates known to be associated with neurodevelopmental outcomes. RESULTS Median postnatal MeHg exposure at 7 years was 2.5 ppm, while the median prenatal MeHg exposure was 3.5 ppm. We found no statistically significant associations between postnatal MeHg exposure and any of the 17 neurodevelopmental outcomes after adjusting for prenatal MeHg exposure and other covariates. CONCLUSIONS These findings are consistent with previous cross-sectional analyses of the SCDS Main Cohort. Continued follow-up of the entire NC2 cohort at later ages with repeated exposure measures is needed to further confirm these findings.
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Affiliation(s)
- Jonathan K Klus
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Sally W Thurston
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Gary J Myers
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Gene E Watson
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Matthew D Rand
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Tanzy M Love
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Alison J Yeates
- Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, Coleraine, Northern Ireland, UK
| | - Maria S Mulhern
- Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, Coleraine, Northern Ireland, UK
| | - Emeir M McSorley
- Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, Coleraine, Northern Ireland, UK
| | - J J Strain
- Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, Coleraine, Northern Ireland, UK
| | | | - Edwin van Wijngaarden
- University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA.
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Packull-McCormick S, Ashley-Martin J, Singh K, Fisher M, Arbuckle TE, Lanphear B, Laird BD, Muckle G, Booij L, Asztalos E, Walker M, Bouchard MF, Saint-Amour D, Boivin M, Borghese M. Prenatal and concurrent blood mercury concentrations and associations with IQ in canadian preschool children. ENVIRONMENTAL RESEARCH 2023; 233:116463. [PMID: 37343750 DOI: 10.1016/j.envres.2023.116463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/12/2023] [Accepted: 06/18/2023] [Indexed: 06/23/2023]
Abstract
BACKGROUND Prenatal and childhood mercury (Hg) exposures have been associated with negative impacts on child neurodevelopment. It is unclear if associations persist at the low Hg exposures typical in Western countries. OBJECTIVE To examine associations between prenatal/childhood blood Hg concentrations and child IQ in Canadian male and female children while considering the potential modifying role of prenatal fish consumption. METHODS We analyzed data from the Maternal-Infant Research on Environmental Chemicals study. Hg was measured in first trimester (n = 527), cord (n = 430), and child (at 3-4 years of age, n = 355) blood and examined sex-stratified associations between blood Hg and children's Full Scale IQ (FSIQ), Verbal IQ (VIQ), Performance IQ (PIQ), and General Language Composite (GLC) scores (assessed with WPPSI-III). Prenatal Hg analyses were further stratified by prenatal fish consumption (low: 0-2, moderate: 3-7, or high: ≥8 times/month). RESULTS Higher cord blood Hg concentrations were associated with lower PIQ (ß = -3.27; 95%CI: 6.44, -0.09) in male children with the lowest prenatal fish consumption. Progressively stronger positive associations were observed with PIQ in male children for moderate (ß = 1.08; 95%CI: 0.10, 2.26) and high (ß = 3.07; 95%CI: 1.95, 4.19) prenatal fish consumption. Cord blood Hg concentrations were positively associated with female children's FSIQ (ß = 1.29; 95% CI: 0.77, 1.81) and PIQ (ß = 2.01; 95% CI: 1.19, 2.83); however, when stratified only in the highest fish consumption subgroup. Among female children, higher child blood Hg concentrations were associated with an approximately 1-point increase in FSIQ, VIQ, and GLC. CONCLUSIONS Prenatal exposure to low levels of Hg was associated with lower PIQ scores in male children with low prenatal fish intake. Positive associations between cord and child blood Hg concentrations and IQ were primarily observed in female children and may be due to beneficial effects of prenatal fish intake.
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Affiliation(s)
- Sara Packull-McCormick
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada; School of Public Health Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Jillian Ashley-Martin
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Kavita Singh
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Mandy Fisher
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Tye E Arbuckle
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | | | - Brian D Laird
- School of Public Health Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Gina Muckle
- Université Laval, QC, G1V 0A6, Canada; Quebec CHU Research Center, QC, G1E 6W2, Canada
| | - Linda Booij
- Research Centre, Douglas Mental Health University Institute & Department of Psychiatry, McGill University, Montreal, QC, H4H 1R3, Canada; CHU Sainte-Justine Research Rentre, QC, H3T 1C5, Canada
| | - Elizabeth Asztalos
- Department of Newborn & Developmental Paediatrics, Sunnybrook Health Sciences Centre, University of Toronto, ON, M5G 1V7, Canada
| | - Mark Walker
- Faculty of Medicine, University of Ottawa, ON, K1H 8M5, Canada
| | - Maryse F Bouchard
- Department of Environmental and Occupational Health, University of Montreal School of Public Health, QC, H3N 1X9, Canada
| | | | | | - Michael Borghese
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada.
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Ventre S, Desai G, Roberson R, Kordas K. Toxic metal exposures from infant diets: Risk prevention strategies for caregivers and health care professionals. Curr Probl Pediatr Adolesc Health Care 2022; 52:101276. [PMID: 36266220 DOI: 10.1016/j.cppeds.2022.101276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Concerns are growing regarding the presence of toxic elements such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in the ingredients and prepared foods for infants and young children. There are few clear, evidence-based, guidelines on the maximum tolerable limits of toxicants in foods and little understanding of toxicant exposure or adverse health effects attributable to dietary exposure. Caregivers are faced with the burden of making decisions about which foods to select, how often to feed them to their children, and what foods to limit. This article reviews the current literature and existing recommendations on dietary exposure to toxic elements in children under 2 years of age, and their health effects in early childhood-focusing on growth, neurodevelopment, and immune function. The article also outlines best practices for healthcare providers to address the concerns of toxic element exposure through the diet in young children. Several foods consistently appear in the literature as potential sources of toxic element exposure. Contaminated drinking and cooking water, including water used to prepare infant formula, could also be a major exposure source. In the absence of stronger evidence on effects of dietary modification, exclusive breastfeeding until six months of age, followed by a diverse diet are some strategies to reduce dietary toxic element exposure while ensuring an adequate and balanced nutrient intake. Healthcare providers can support families by sharing information and encouraging blood Pb testing, the only element for which such testing is currently recommended.
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Affiliation(s)
- Sarah Ventre
- Department of Pediatrics, University at Buffalo, USA; New York State Children's Environmental Health Center, USA.
| | - Gauri Desai
- Department of Epidemiology and Environmental Health, University at Buffalo, USA
| | | | - Katarzyna Kordas
- Department of Epidemiology and Environmental Health, University at Buffalo, USA
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Kim B, Shah S, Park HS, Hong YC, Ha M, Kim Y, Kim BN, Kim Y, Ha EH. Adverse effects of prenatal mercury exposure on neurodevelopment during the first 3 years of life modified by early growth velocity and prenatal maternal folate level. ENVIRONMENTAL RESEARCH 2020; 191:109909. [PMID: 32871452 DOI: 10.1016/j.envres.2020.109909] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 05/30/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS Previous studies have suggested that mercury exposure and folate levels during pregnancy may influence early childhood neurodevelopment. Rapid catch-up growth in children is associated with an increased risk of pathological nervous system development. We evaluated whether the association between prenatal folate and mercury-related neuropsychological dysfunction was modified by growth velocity during childhood. METHODS The Mothers and Children's Environmental Health (MOCEH) birth cohort study began in 2006 and by 2010, 1751 women had been enrolled before the second trimester of their pregnancy along with their partners. Participants visited the research center at birth and 6, 12, 24, and 36 months. We measured mercury levels in maternal and cord blood and folate in maternal serum. Questionnaires to evaluate the environment and health of their child were administered and anthropometric factors including body weight and height were measured. Certified investigators used the Bayley test to measure neurobehavioral outcomes. We calculated postnatal growth change as the change in infant weight for-age z-score between birth and 3 years. Multiple linear regression and mixed models were used to examine the association between mercury exposure and children's neurodevelopment as well as the modifying effects of folate and growth velocity. RESULTS A total of 30.6% of children experienced rapid growth during the first 3 years of life. Median values of mercury in the low folate group were significantly higher in rapid growers (3.41 μg/L in maternal blood and 5.63 μg/L in cord blood) than in average/slow growers (3.05 μg/L in maternal blood and 5.19 μg/L in cord blood). Rapid growers were also significantly associated with decreased psychomotor development scores during the first 3 years of life and with having mothers who had low prenatal folate levels, even after adjusting for potential confounders. CONCLUSION Prenatal mercury exposure adversely affects infant neurodevelopment and is associated with rapid growth during the first 3 years of life. This effect was limited to children whose mothers had low prenatal folate levels, suggesting a protective effect of folate against developmental neurotoxicity due to mercury exposure and rapid catch-up growth.
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Affiliation(s)
- Byungmi Kim
- National Cancer Control Institute, National Cancer Center, Goyang, Republic of Korea
| | - Surabhi Shah
- Department of Occupational and Environmental Medicine, College of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea
| | - Hye-Sook Park
- Department of Preventive Medicine, College of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea
| | - Yun-Chul Hong
- Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Mina Ha
- Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan, Republic of Korea
| | - Yangho Kim
- Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Boong-Nnyun Kim
- Division of Child & Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yeni Kim
- Department of Child and Adolescent Psychiatry, National Center for Mental Health, Seoul, Republic of Korea
| | - Eun-Hee Ha
- Department of Occupational and Environmental Medicine, College of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea.
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Gagnon-Chauvin A, Bastien K, Saint-Amour D. Environmental toxic agents: The impact of heavy metals and organochlorides on brain development. HANDBOOK OF CLINICAL NEUROLOGY 2020; 173:423-442. [PMID: 32958188 DOI: 10.1016/b978-0-444-64150-2.00030-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Exposure to environmental toxicants can have deleterious effects on the development of physical, cognitive, and mental health. Extensive laboratory and clinical studies have demonstrated how the developing brain is uniquely sensitive to toxic agents. This chapter focuses on the main neurologic impairments linked to prenatal and postnatal exposure to lead, methylmercury, and polychlorinated biphenyls, three legacy environmental contaminants whose neurotoxic effects have been extensively studied with respect to cognitive and behavioral development. The main cognitive, emotion regulation, sensory, and motor impairments in association with these contaminants are briefly reviewed, including the underlying neural mechanisms such as neuropathologic damages, brain neurotransmission, and endocrine system alterations. The use of neuroimaging as a novel tool to better understand how the brain is affected by exposure to environmental contaminants is also discussed.
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Affiliation(s)
- Avril Gagnon-Chauvin
- Department of Psychology, Université du Québec à Montréal, Montréal, QC, Canada; Research Centre, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada
| | - Kevin Bastien
- Department of Psychology, Université du Québec à Montréal, Montréal, QC, Canada; Research Centre, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada
| | - Dave Saint-Amour
- Department of Psychology, Université du Québec à Montréal, Montréal, QC, Canada; Research Centre, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada.
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Dórea JG. Environmental exposure to low-level lead (Pb) co-occurring with other neurotoxicants in early life and neurodevelopment of children. ENVIRONMENTAL RESEARCH 2019; 177:108641. [PMID: 31421445 DOI: 10.1016/j.envres.2019.108641] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
Lead (Pb) is a worldwide environmental contaminant that even at low levels influences brain development and affects neurobehavior later in life; nevertheless it is only a small fraction of the neurotoxicant (NT) exposome. Exposure to environmental Pb concurrent with other NT substances is often the norm, but their joint effects are challenging to study during early life. The aim of this review is to integrate studies of Pb-containing NT mixtures during the early life and neurodevelopment outcomes of children. The Pb-containing NT mixtures that have been most studied involve other metals (Mn, Al, Hg, Cd), metalloids (As), halogen (F), and organo-halogen pollutants. Co-occurring Pb-associated exposures during pregnancy and lactation depend on the environmental sources and the metabolism and half-life of the specific NT contaminant; but offspring neurobehavioral outcomes are also influenced by social stressors. Nevertheless, Pb-associated effects from prenatal exposure portend a continued burden on measurable neurodevelopment; they thus favor increased neurological health issues, decrements in neurobehavioral tests and reductions in the quality of life. Neurobehavioral test outcomes measured in the first 1000 days showed Pb-associated negative outcomes were frequently noticed in infants (<6 months). In older (preschool and school) children studies showed more variations in NT mixtures, children's age, and sensitivity and/or specificity of neurobehavioral tests; these variations and choice of statistical model (individual NT stressor or collective effect of mixture) may explain inconsistencies. Multiple exposures to NT mixtures in children diagnosed with 'autism spectrum disorders' (ASD) and 'attention deficit and hyperactivity disorders' (ADHD), strongly suggest a Pb-associated effect. Mixture potency (number or associated NT components and respective concentrations) and time (duration and developmental stage) of exposure often showed a measurable impact on neurodevelopment; however, net effects, reversibility and/or predictability of delays are insufficiently studied and need urgent attention. Nevertheless, neurodevelopment delays can be prevented and/or attenuated if public health policies are implemented to protect the unborn and the young child.
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Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília, 70919-970, DF, Brazil.
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Mercury Exposure in Mother-Children Pairs in A Seafood Eating Population: Body Burden and Related Factors. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16122238. [PMID: 31242636 PMCID: PMC6617287 DOI: 10.3390/ijerph16122238] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/21/2019] [Accepted: 06/22/2019] [Indexed: 01/15/2023]
Abstract
Background: Mercury is a neurotoxin that affects neurodevelopment in children; however, its association at the lowest concentration is not clear. The main objective of this study is to measure and evaluate mercury concentrations in mother–child pairs and its association demographics, lifestyle, and dietary factors within the Pacific Island Families living in Auckland, New Zealand. Methods: Mercury exposure was assessed in a sub-sample of mother–child pairs who were a part of the Pacific Island Families birth cohort, in Auckland, New Zealand at the 6-year phase. Hair samples were collected from both mothers and their children to determine mercury concentrations. Total mercury was measured using inductively coupled plasma mass spectrometry for hair samples. An interviewer-based reliable food frequency questionnaire (FFQ) examined the frequency of seafood by all the participants. Other variables such as sociodemographic (ethnicity and gender), lifestyle factors (income, education, and smoking status) and health outcomes (child behaviour and obesity) were also collected. Results: In this study, 41% of both mothers and their children had mercury concentrations above the US Environmental Protection Agency (EPA) recommended value of 1 µg/g. Most of the participants ate fish 3 or more times a week. A significant correlation was observed between mother and child hair mercury concentrations (Spearman Rho 0.79 (95% confidence interval (CI): 0.65, 0.88)). Conclusions: Mercury levels in children can be affected by their mothers’ levels due to similar eating patterns.
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Dórea JG. Multiple low-level exposures: Hg interactions with co-occurring neurotoxic substances in early life. Biochim Biophys Acta Gen Subj 2018; 1863:129243. [PMID: 30385391 DOI: 10.1016/j.bbagen.2018.10.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/01/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022]
Abstract
All chemical forms of Hg can affect neurodevelopment; however, low levels of organic Hg (methylmercury-MeHg and ethylmercury-EtHg in Thimerosal-containing vaccines, hereafter 'TCV') exposures during early life (pregnancy and lactation) co-occur with other environmental neurotoxic substances. These neurotoxicants may act in parallel, synergistically, or antagonistically to Hg. Nevertheless, the risks of neurotoxicity associated with multiple neuro-toxicants depend on type, time, combinations of exposure, and environmental and/or genetic-associated factors. Neurological developmental disorders, delays in cognition and behavioral outcomes associated with multiple exposures (which include Hg) may show transient or lasting outcomes depending on constitutional and/or environmental factors that can interact to neutralize, aggravate or attenuate these effects; often these studies are challenging to interpret. During pregnancy and lactation, fish-MeHg exposure is frequently confounded with the opposing effects of neuroactive nutrients (in fish) that lead to positive, negative, or no effects on neurobehavioral tests. In infancy, exposures to acute binary mixtures (TCV- EtHg and Al-adjuvants in infant immunizations) are associated with increased risks of tics and other developmental disorders. Despite the certitude that promulgates single environmental neurotoxicants, empirical comparisons of combined exposures indicate that Hg-related outcome is uneven. Hg in combination with other neurotoxic mixtures may elevate risks of neurotoxicity, but these risks arise in circumstances that are not yet predictable. Therefore, to achieve the goals of the Minamata treaty and to safeguard the health of children, low levels of mercury exposure (in any chemical form) needs to be further reduced whether the source is environmental (air- and food-borne) or iatrogenic (pediatric TCVs).
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Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília 70919-970, DF, Brazil..
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Oliveira CS, Nogara PA, Ardisson-Araújo DMP, Aschner M, Rocha JBT, Dórea JG. Neurodevelopmental Effects of Mercury. ADVANCES IN NEUROTOXICOLOGY 2018; 2:27-86. [PMID: 32346667 PMCID: PMC7188190 DOI: 10.1016/bs.ant.2018.03.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The toxicology of mercury (Hg) is of concern since this metal is ubiquitously distributed in the environment, and living organisms are routinely exposed to Hg at low to high levels. The toxic effects of Hg are well studied and it is known that they may differ depending on the Hg chemical species. In this chapter, we emphasize the neurotoxic effects of Hg during brain development. The immature brain is more susceptible to Hg exposure, since all the Hg chemical forms, not only the organic ones, can harm it. The possible consequences of Hg exposure during the early stages of development, the additive effects with other co-occurring neurotoxicants, and the known mechanisms of action and targets will be addressed in this chapter.
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Affiliation(s)
- Cláudia S Oliveira
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Pablo A Nogara
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Daniel M P Ardisson-Araújo
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
- Laboratório de Virologia de Insetos, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, NY, USA
| | - João B T Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - José G Dórea
- Professor Emeritus, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, DF, Brazil
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Cui W, Liu G, Bezerra M, Lagos DA, Li Y, Cai Y. Occurrence of Methylmercury in Rice-Based Infant Cereals and Estimation of Daily Dietary Intake of Methylmercury for Infants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:9569-9578. [PMID: 29067797 DOI: 10.1021/acs.jafc.7b03236] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recent reports of elevated levels of methylmercury (MeHg) in rice revealed the possible occurrence of MeHg in infant rice cereals, leading to potential MeHg exposure through cereal consumption. Total mercury (THg) and MeHg levels in 119 infant cereal samples commonly marketed in the United States and China and estimated daily intake of MeHg through cereal consumption were determined. Concentrations of THg and MeHg in the tested cereal samples ranged from 0.35 to 15.9 μg/kg and from 0.07 to 13.9 μg/kg with means of 2.86 and 1.61 μg/kg, respectively. Rice-based cereals contained MeHg levels significantly higher than those of nonrice cereals, indicating that MeHg in rice could be source of MeHg in cereals. Cereal consumption could be a potential pathway of MeHg exposure for infants, as the EDI through cereal consumption amounted to 4-122% of the MeHg reference dose, suggesting the necessity of further evaluation of the potential health risk of dietary MeHg exposure to infants.
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Affiliation(s)
- Wenbin Cui
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
| | - Guangliang Liu
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
- Southeast Environmental Research Center, Florida International University , Miami, Florida 33199, United States
| | - Mayara Bezerra
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
| | - Danielle A Lagos
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
| | - Yanbin Li
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China , Qingdao, China
| | - Yong Cai
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
- Southeast Environmental Research Center, Florida International University , Miami, Florida 33199, United States
- Institute of Environment and Health, Jianghan University , Wuhan, China
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Karatela S, Paterson J, Ward NI. Domain specific effects of postnatal toenail methylmercury exposure on child behaviour. J Trace Elem Med Biol 2017; 41:10-15. [PMID: 28347455 DOI: 10.1016/j.jtemb.2017.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Very little is known about the relationship between postnatal methylmercury concentrations (via toenails as bioindicator) and behavioural characteristics of Pacific Island children living in New Zealand. The aim of this study was to explore the association between total mercury exposure and different domains of behavioural problems in Pacific children. MATERIALS AND METHODS A sample of nine-year-old Pacific Island children resident in Auckland, New Zealand participated in this study. Total mercury was determined in biological samples (toenail clippings) on behavioural problems as identified by mothers (using the child behaviour checklist). Specific behavioural domains, particularly aggression, rule breaking, attention and social problems were studied in relation to mercury exposure using toenails. The determination of mercury concentration in toenail clippings, after acid digestion was carried out using inductively coupled plasma mass spectrometry. RESULTS The observational study was conducted between July 2010 and July 2011 in which 278 eligible nine-year-old Pacific Island children were enrolled (Girls n=58%; boys n=42%). FINDINGS showed that 21% of the children had total toenail mercury concentrations (1.5μg/g to 6μg/g) higher than the United State Environmental Protection Agency recommended levels (RfD; 1μg/g Hg) for optimal health in children. Aggressive behaviour was associated with total toenail mercury exposure after adjusting for gender, ethnicity and income levels (OR: 2.15 95% CI 1.45, 3.18 p-value <0.05; OR 1.38 95% CI 0.83, 1.2 p value <0.05, respectively). CONCLUSIONS Overall, this research contributes to the understanding of total toenail mercury concentrations for Pacific people in New Zealand using toenail clippings as biomarkers in terms of associations with child behavioural problems. Mercury in toenails demonstrated a moderate association with a specific behavioural domain - aggressive behaviour.
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Affiliation(s)
- Shamshad Karatela
- Middlemore Hospital,100 Hospital Road, Otahuhu, 1640, Auckland, New Zealand.
| | - Janis Paterson
- AUT University, School of Public Health and Psychosocial Studies, Auckland, New Zealand
| | - Neil I Ward
- University of Surrey, Department of Chemistry FEPS, Guildford, Surrey GU2 7XH, UK
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Gustin K, Tofail F, Mehrin F, Levi M, Vahter M, Kippler M. Methylmercury exposure and cognitive abilities and behavior at 10years of age. ENVIRONMENT INTERNATIONAL 2017; 102:97-105. [PMID: 28216013 DOI: 10.1016/j.envint.2017.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 05/26/2023]
Abstract
BACKGROUND Methylmercury (MeHg) is a known developmental neurotoxicant present in fish, yet the impact of childhood exposure is uncertain, especially in children with poor nutrition. OBJECTIVES To evaluate associations of MeHg exposure with cognitive abilities and behavior in children from a poor rural area in Bangladesh. METHODS The MeHg exposure was assessed in 1434 ten-year-old children by measuring mercury concentrations in hair (hair-Hg), using inductively coupled plasma mass spectrometry. Cognitive abilities were assessed with the Wechsler Intelligence Scale for Children (4th edition), and behavior by the parent-report Strengths and Difficulties Questionnaire. RESULTS Children's median hair-Hg was 674μg/kg (range 70-17,561μg/kg). Concentrations did not differ by distance from scalp, indicating a similar exposure over time. No multivariable-adjusted associations were observed between the children's hair-Hg and their cognitive abilities. However, children in the highest tertile of hair-Hg had a lower prevalence of hyperactivity (OR: 0.61, 95% CI: 0.45-0.83) and peer relationship problems (OR: 0.58, 95% CI: 0.44-0.76), compared to children in the lowest tertile. The corresponding ORs were slightly stronger in children from families with lower socioeconomic status (OR: 0.56, 95% CI: 0.34-0.90 and OR: 0.48, 95% CI: 0.30-0.74) than in children from families with higher socioeconomic status (OR: 0.73, 95% CI: 0.49-1.08 and OR: 0.72, 95% CI: 0.51-1.02). Similar stronger ORs were observed in underweight children. CONCLUSION MeHg exposure was not associated with cognitive function, but inversely associated with certain adverse behavior. More studies are needed concerning the risk-benefit of different fish consumption in rural Bangladesh.
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Affiliation(s)
- Klara Gustin
- Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden
| | - Fahmida Tofail
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Fardina Mehrin
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Michael Levi
- Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden
| | - Marie Vahter
- Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden
| | - Maria Kippler
- Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden.
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Heyer DB, Meredith RM. Environmental toxicology: Sensitive periods of development and neurodevelopmental disorders. Neurotoxicology 2017; 58:23-41. [DOI: 10.1016/j.neuro.2016.10.017] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/25/2016] [Accepted: 10/31/2016] [Indexed: 11/16/2022]
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14
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van Wijngaarden E, Thurston SW, Myers GJ, Harrington D, Cory-Slechta DA, Strain JJ, Watson GE, Zareba G, Love T, Henderson J, Shamlaye CF, Davidson PW. Methyl mercury exposure and neurodevelopmental outcomes in the Seychelles Child Development Study Main cohort at age 22 and 24years. Neurotoxicol Teratol 2016; 59:35-42. [PMID: 27989696 DOI: 10.1016/j.ntt.2016.10.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 09/29/2016] [Accepted: 10/26/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND All fish contain methyl mercury (MeHg), a known neurotoxicant at adequate dosage. There is still substantial scientific uncertainty about the consequences, if any, of mothers consuming fish with naturally-acquired levels of MeHg contamination. In 1989-1990, we recruited the Main Cohort of the Seychelles Child Development Study to assess the potential developmental effects of prenatal MeHg exposure. We report here on associations with neurodevelopmental outcomes obtained at 22 and 24years of age. METHODS Neurodevelopmental tests at 22years included the Boston Naming Test, Cambridge Neuropsychological Test Automated Battery (CANTAB), and the Profile of Mood States. At 24years, we administered the Stroop Word-Color Test, the Barkley Adult ADHD Rating Scale, the Test of Variables of Attention, and the Finger Tapping test. We also administered a healthy behaviors survey at both ages. Primary analyses examined covariate-adjusted associations in multiple linear regression models with prenatal MeHg exposure. In secondary analyses we also examined associations with recent postnatal MeHg exposure. RESULTS We did not observe adverse associations between prenatal MeHg exposure and any of the measured endpoints. Some measures of attention, executive function, and delayed recall showed improved performance with increasing exposure. Secondary analysis did not show consistent patterns of association with postnatal exposure. CONCLUSIONS Our cohort has been examined at ten different ages over 24years of follow-up. Findings suggest that prenatal and recent postnatal MeHg exposure from ocean fish consumption is not adversely associated with neurobehavioral development at levels that are about ten times higher than typical U.S. exposures.
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Affiliation(s)
- Edwin van Wijngaarden
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
| | - Sally W Thurston
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Gary J Myers
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Donald Harrington
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | | | - J J Strain
- Ulster University, Coleraine, Northern Ireland, United Kingdom
| | - Gene E Watson
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Grazyna Zareba
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Tanzy Love
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | | | | | - Philip W Davidson
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
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15
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Ruiz JDC, Quackenboss JJ, Tulve NS. Contributions of a Child's Built, Natural, and Social Environments to Their General Cognitive Ability: A Systematic Scoping Review. PLoS One 2016; 11:e0147741. [PMID: 26840411 PMCID: PMC4739499 DOI: 10.1371/journal.pone.0147741] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/09/2015] [Indexed: 12/24/2022] Open
Abstract
The etiology of a child's cognitive ability is complex, with research suggesting that it is not attributed to a single determinant or even a defined period of exposure. Rather, cognitive development is the product of cumulative interactions with the environment, both negative and positive, over the life course. The aim of this systematic scoping review was to collate evidence associated with children's cognitive health, including inherent factors as well as chemical and non-chemical stressors from the built, natural, and social environments. Three databases were used to identify recent epidemiological studies (2003-2013) that examined exposure factors associated with general cognitive ability in children. Over 100 factors were evaluated from 258 eligible studies. We found that recent literature mainly assessed the hypothesized negative effects of either inherent factors or chemical exposures present in the physical environment. Prenatal growth, sleep health, lead and water pollutants showed consistent negative effects. Of the few studies that examined social stressors, results consistently showed cognitive development to be influenced by both positive and negative social interactions at home, in school or the community. Among behavioral factors related to diet and lifestyle choices of the mother, breastfeeding was the most studied, showing consistent positive associations with cognitive ability. There were mostly inconsistent results for both chemical and non-chemical stressors. The majority of studies utilized traditional exposure assessments, evaluating chemical and non-chemical stressors separately. Collective evidence from a limited number of studies revealed that cumulative exposure assessment that incorporates multiple chemical and non-chemical stressors over the life course may unravel the variability in effect on cognitive development and help explain the inconsistencies across studies. Future research examining the interactions of multiple stressors within a child's total environment, depicting a more real-world exposure, will aid in understanding the cumulative effects associated with a child's ability to learn.
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Affiliation(s)
- Jazmin Del Carmen Ruiz
- Oak Ridge Institute for Science and Education, Research Participation Program, Oak Ridge, TN, United States of America
- Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States of America
| | - James J. Quackenboss
- Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Las Vegas, NV, United States of America
| | - Nicolle S. Tulve
- Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States of America
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16
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Wang Y, Chen A, Dietrich KN, Radcliffe J, Caldwell KL, Rogan WJ. Postnatal exposure to methyl mercury and neuropsychological development in 7-year-old urban inner-city children exposed to lead in the United States. Child Neuropsychol 2013; 20:527-38. [PMID: 23971942 DOI: 10.1080/09297049.2013.824955] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND The most common route for general population exposure to methyl mercury (MeHg) is fish consumption. Recommendations to pregnant women about consuming fish contaminated with MeHg are also applied to children, but there are few studies available about the effects of low-level postnatal MeHg exposure in them. OBJECTIVES To investigate the association between postnatal methyl mercury exposure and neuropsychological development in a study of children also exposed to lead, both measured at 7 years. METHODS We measured MeHg concentrations in blood samples from the Treatment of Lead-Exposed Children (TLC) trial in which 780 children with elevated concentrations of lead in blood were followed with neuropsychological tests from ages 12-33 months through 7 years. Here we examine blood MeHg concentration and neuropsychological test scores, both measured at age 7 years. We used a maximum likelihood method to estimate geometric mean MeHg concentration and generalized linear regression models to analyze MeHg and neuropsychological test scores. RESULTS Geometric mean MeHg concentration was 0.56 (95% confidence interval: 0.52, 0.59) μ g/L. A 1 μ g/L increase in MeHg was associated with a 2.1 (95% confidence interval: 0.4, 3.8) point increase in Full-Scale IQ and 0.2 (95% confidence interval: 0.02, 0.4) point increase in Learning Slopeindex T-score on a test of verbal memory. CONCLUSIONS Our results suggest that the relatively low MeHg exposure in US school-aged children from this population has no detectable adverse effect on neuropsychological development. The positive associations observed between MeHg and neurodevelopment may indirectly reflect consumption of beneficial polyunsaturated fatty acids from seafood.
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Affiliation(s)
- Yan Wang
- a Epidemiology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , North Carolina , USA
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17
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Hassauer M, Kaiser E, Schneider K, Schuhmacher‐Wolz U. Collate the literature on toxicity data on mercury in experimental animals and humans (Part I – Data on organic mercury). ACTA ACUST UNITED AC 2012. [DOI: 10.2903/sp.efsa.2012.en-297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Hassauer
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Eva Kaiser
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Klaus Schneider
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
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18
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Scientific Opinion on the risk for public health related to the presence of mercury and methylmercury in food. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2985] [Citation(s) in RCA: 276] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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19
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Hara N, Saito H, Takahashi K, Takeda M. Lower urinary tract symptoms in patients with Niigata Minamata disease: A case-control study 50 years after methyl mercury pollution. Int J Urol 2012; 20:610-5. [DOI: 10.1111/iju.12001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 10/08/2012] [Indexed: 12/15/2022]
Affiliation(s)
- Noboru Hara
- Division of Urology; Department of Regenerative and Transplant Medicine; Graduate School of Medical and Dental Sciences; Niigata University; Niigata; Japan
| | - Hisashi Saito
- Department of Internal Medicine; Kido Hospital; Niigata; Japan
| | - Kota Takahashi
- Division of Urology; Department of Regenerative and Transplant Medicine; Graduate School of Medical and Dental Sciences; Niigata University; Niigata; Japan
| | - Masayuki Takeda
- Department of Urology; Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi; Japan
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20
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Karagas MR, Choi AL, Oken E, Horvat M, Schoeny R, Kamai E, Cowell W, Grandjean P, Korrick S. Evidence on the human health effects of low-level methylmercury exposure. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:799-806. [PMID: 22275730 PMCID: PMC3385440 DOI: 10.1289/ehp.1104494] [Citation(s) in RCA: 458] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 01/24/2012] [Indexed: 05/17/2023]
Abstract
BACKGROUND Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by beneficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited. OBJECTIVES We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide. DATA SOURCES AND EXTRACTION We reviewed the published literature for original human epidemiologic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon). DATA SYNTHESIS Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent. CONCLUSIONS Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts surrounding MeHg exposure.
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Affiliation(s)
- Margaret R Karagas
- Section of Biostatistics and Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
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21
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Moon HB, Kim SJ, Park H, Jung YS, Lee S, Kim YH, Choi M. Exposure assessment for methyl and total mercury from seafood consumption in Korea, 2005 to 2008. ACTA ACUST UNITED AC 2011; 13:2400-5. [PMID: 21847486 DOI: 10.1039/c1em10504c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reports on the occurrence and intake assessment of mercury for Korean seafood are currently not available. This is the first report to estimate the intake of methyl (Me-Hg) and total mercury (T-Hg) from seafood consumption in Korea. The concentrations of Me-Hg and T-Hg in seafood ranged from 1.02 to 780 (mean: 55.6) ng g(-1) wet weight and 4.89 to 1008 (mean: 100) ng g(-1) wet weight, respectively. The residue levels of Me-Hg and T-Hg in Korean seafood were moderate compared with those found in other countries. The methylation ratios of fish, cephalopods and crustaceans were similar, but shellfish had lower values compared with other species. The intakes of Me-Hg and T-Hg from seafood consumption for the general population were estimated to be 38.8 and 73.8 ng kg(-1) body weight per day, respectively. Mackerel, tuna and squid made the highest contributions to the total intake of these contaminants. Among eight age groups, 30-49 year and 3-6 year age groups had the highest exposure to Me-Hg and T-Hg. The concentrations and intakes of Me-Hg and T-Hg from Korean seafood were less than the allowable residue levels and threshold intake levels suggested by Korean and international authorities. The present study may be useful for risk management of mercury in Korean seafood.
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Affiliation(s)
- Hyo-Bang Moon
- Marine Environment Analysis Laboratory (MEAL), Department of Environmental Marine Sciences, College of Science and Technology, Hanyang University, Ansan, 426-791, Republic of Korea.
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22
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Azevedo BF, Futuro Neto HDA, Stefanon I, Vassallo DV. Acute cardiorespiratory effects of intracisternal injections of mercuric chloride. Neurotoxicology 2011; 32:350-4. [DOI: 10.1016/j.neuro.2011.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 12/22/2010] [Accepted: 02/24/2011] [Indexed: 11/16/2022]
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Chen A, Dietrich KN, Huo X, Ho SM. Developmental neurotoxicants in e-waste: an emerging health concern. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:431-8. [PMID: 21081302 PMCID: PMC3080922 DOI: 10.1289/ehp.1002452] [Citation(s) in RCA: 163] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 10/20/2010] [Indexed: 05/02/2023]
Abstract
OBJECTIVE Electronic waste (e-waste) has been an emerging environmental health issue in both developed and developing countries, but its current management practice may result in unintended developmental neurotoxicity in vulnerable populations. To provide updated information about the scope of the issue, presence of known and suspected neurotoxicants, toxicologic mechanisms, and current data gaps, we conducted this literature review. DATA SOURCES We reviewed original articles and review papers in PubMed and Web of Science regarding e-waste toxicants and their potential developmental neurotoxicity. We also searched published reports of intergovernmental and governmental agencies and nongovernmental organizations on e-waste production and management practice. DATA EXTRACTION We focused on the potential exposure to e-waste toxicants in vulnerable populations-that is, pregnant women and developing children-and neurodevelopmental outcomes. In addition, we summarize experimental evidence of developmental neurotoxicity and mechanisms. DATA SYNTHESIS In developing countries where most informal and primitive e-waste recycling occurs, environmental exposure to lead, cadmium, chromium, polybrominated diphenyl ethers, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons is prevalent at high concentrations in pregnant women and young children. Developmental neurotoxicity is a serious concern in these regions, but human studies of adverse effects and potential mechanisms are scarce. The unprecedented mixture of exposure to heavy metals and persistent organic pollutants warrants further studies and necessitates effective pollution control measures. CONCLUSIONS Pregnant women and young children living close to informal e-waste recycling sites are at risk of possible perturbations of fetus and child neurodevelopment.
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Affiliation(s)
- Aimin Chen
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.
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Cao Y, Chen A, Jones RL, Radcliffe J, Dietrich KN, Caldwell KL, Peddada S, Rogan WJ. Efficacy of succimer chelation of mercury at background exposures in toddlers: a randomized trial. J Pediatr 2011; 158:480-485.e1. [PMID: 20889164 PMCID: PMC3086399 DOI: 10.1016/j.jpeds.2010.08.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 07/19/2010] [Accepted: 08/20/2010] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To examine whether succimer, a mercaptan compound known to reduce blood lead concentration in children, reduces blood mercury concentration. STUDY DESIGN We used samples from a randomized clinical trial of succimer chelation for lead-exposed children. We measured mercury levels in pre-treatment samples from 767 children. We also measured mercury levels in blood samples drawn 1 week after treatment began (n = 768) and in a 20% random sample of the children who received the maximum 3 courses of treatment (n = 67). A bootstrap-based isotonic regression method was used to compare the trend with time in the difference between the adjusted mean mercury concentrations in the succimer group and that in the placebo group. RESULTS The adjusted mean organic mercury concentration in the succimer group relative to the placebo group fell from 99% at baseline to 82% after 3 courses of treatment (P for trend = .048), but this resulted from the prevention of the age-related increase in the succimer group. CONCLUSION Succimer chelation for low level organic mercury exposure in children has limited efficacy.
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Affiliation(s)
- Yang Cao
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
- Department of Health Statistics, Faculty of Health Services, Second Military Medical University, Shanghai, China
| | - Aimin Chen
- Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Robert L. Jones
- Inorganic and Radiation Analytical Toxicology Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Jerilynn Radcliffe
- The Children’s Hospital of Philadelphia, and University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Kim N. Dietrich
- Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Kathleen L. Caldwell
- Inorganic and Radiation Analytical Toxicology Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Shyamal Peddada
- Biostatistics Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Walter J. Rogan
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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Yorifuji T, Debes F, Weihe P, Grandjean P. Prenatal exposure to lead and cognitive deficit in 7- and 14-year-old children in the presence of concomitant exposure to similar molar concentration of methylmercury. Neurotoxicol Teratol 2010; 33:205-11. [PMID: 20868742 DOI: 10.1016/j.ntt.2010.09.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Revised: 08/20/2010] [Accepted: 09/16/2010] [Indexed: 10/19/2022]
Abstract
Few studies have examined the effects of mixed metal exposures in humans. We have evaluated the effect of prenatal lead exposure in a Faroese birth cohort in the presence of similar molar-level exposure to methylmercury. A cohort of 1022 singleton births was assembled in the Faroe Islands during 1986-1987 from whom lead was measured in cord-blood. A total of 896 cohort subjects participated in a clinical examination at age 7 and 808 subjects in a second examination at age 14. We evaluated the association between cord-blood lead concentrations and cognitive deficits (attention/working memory, language, visuospatial, and memory) using multiple regression models. Overall, the lead concentration showed no clear pattern of association. However, in subjects with a low methylmercury exposure, after inclusion of statistical interaction terms, lead-associated adverse effects on cognitive functions were observed. In particular, higher cord-blood lead was associated with a lower digit span forward score on the Wechsler Intelligence Scale for Children-Revised (WISC-R) [beta=-1.70, 95% confidence interval (CI): -3.12 to -0.28] at age 7 and a lower digit span backward score on the WISC-R (beta=-2.73, 95%CI: -4.32 to -1.14) at age 14. Some interaction terms between lead and methylmercury suggested that the combined effect of the exposures was less than additive. The present study indicates that adverse effects of exposure may be overlooked if the effects of a co-pollutant are ignored. The present study supports the existence of adverse effects on cognitive functions at prenatal lead exposures corresponding to an average cord-blood concentration of 16 μg/L.
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Affiliation(s)
- Takashi Yorifuji
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02215, USA.
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26
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Davidson PW, Leste A, Benstrong E, Burns CM, Valentin J, Sloane-Reeves J, Huang LS, Miller WA, Gunzler D, van Wijngaarden E, Watson GE, Zareba G, Shamlaye CF, Myers GJ. Fish consumption, mercury exposure, and their associations with scholastic achievement in the Seychelles Child Development Study. Neurotoxicology 2010; 31:439-47. [PMID: 20576509 PMCID: PMC2934742 DOI: 10.1016/j.neuro.2010.05.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 05/18/2010] [Accepted: 05/20/2010] [Indexed: 11/17/2022]
Abstract
Studies of neurodevelopmental outcomes in offspring exposed to MeHg from maternal consumption of fish have primarily measured cognitive abilities. Reported associations have been subtle and in both adverse and beneficial directions. Changes in functional outcomes such as school achievement and behavior in exposed children and adolescents have not been examined. We undertook an assessment of school success of children in the Seychelles Child Development Study (SCDS) main cohort to determine if there were any associations with either prenatal or recent postnatal MeHg exposure. The primary endpoints were Seychelles nationally standardized end-of-year examinations given when the cohort children were 9 and 17 years of age. A subgroup (n=215) from the main cohort was also examined at 9 years of age using a regional achievement test called SACMEQ. Prenatal MeHg exposure was 6.8 ppm in maternal hair; recent postnatal exposure was 6.09 ppm at 9 years and 8.0 ppm at 17 years, measured in child hair. Multiple linear regression analyses showed no pattern of associations between prenatal or postnatal exposure, and either the 9- or 17-year end-of-year examination scores. For the subgroup of 215 subjects who participated in the SACMEQ test, there were significant adverse associations between examination scores and postnatal exposure, but only for males. The average postnatal exposure level in child hair for this subgroup was significantly higher than for the overall cohort. These results are consistent with our earlier studies and support the interpretation that prenatal MeHg exposure at dosages achieved by mothers consuming a diet high in fish are not associated with adverse educational measures of scholastic achievement. The adverse association of educational measures with postnatal exposure in males is intriguing, but will need to be confirmed by further studies examining factors that influence scholastic achievement.
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Affiliation(s)
- Philip W Davidson
- University of Rochester, School of Medicine and Dentistry, Department of Pediatrics, Rochester, NY 14642, USA.
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