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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] [What about the content of this article? (0)] [Affiliation(s)] [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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De la Ossa CA, Ramírez-Giraldo AF, Arroyo-Alvis K, Marrugo-Negrete J, Díez S. Neuropsychological effects and cognitive deficits associated with exposure to mercury and arsenic in children and adolescents of the Mojana region, Colombia. Environ Res 2023; 216:114467. [PMID: 36265603 DOI: 10.1016/j.envres.2022.114467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 09/16/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
The present study aims to explore the neuropsychological performance and exposure to mercury (Hg) and arsenic (As) in Colombian children and adolescents considering biomarkers in hair and blood. The total sample consisted of 70 participants from the Mojana region, Colombia. A neuropsychological evaluation protocol was used, consisting of 11 internationally recognized tests, with evidence of national validation and use for measurement in neurotoxicology contexts. A 57.1% of the sample presented levels above the reference value according to the USEPA, the WHO, and the ATSDR for total mercury in hair (HgH), blood mercury (HgB), and/or blood arsenic (AsB). The mean values reported for HgH were 1.76 ± 3.1 μg/g (95% CI 1.02-2.50) with ranges between 0.23 and 17.20; for HgB: 4.11 ± 5.93 μg/l (CI 2.69-5.52), ranging between 0.25 and 25.80, and for AsB: 1.96 ± 2.73 (CI 1.31-2.61) ranging between 0.50 and 15.50. In the comparison of groups in relation to the level of exposure, a significant difference was found (p < 0.05) for the subtest The Boston Naming Test (BNT). Correlation analyses found, on the one hand, significant negative relationships in tests integrated within the verbal (CVB) and executive function (EF) components as well as evidence of positive relationships in the manifestation of errors in their performance with the levels of Hg and/or As transformed by biomarker (Log10). In the linear regression analyses it was found that for each increase in the concentration of HgH, HgB, and AsB it is estimated that, both for the models with and without data adjustment, there is a loss of scores in integrated measures within the CVB and EF for the transformed levels of HgH, HgB, and AsB; and an increase in the reported errors in their processing within these functions. According to these results, exposure to mercury and/or arsenic is related with performance in verbal neuropsychological skills and executive functioning.
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Affiliation(s)
| | | | | | | | - Sergi Díez
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, E-08034, Barcelona, Spain.
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Silman AK, Chhabria R, Hafzalla GW, Giffin L, Kucharski K, Myers K, Culquichicón C, Montero S, Lescano AG, Vega CM, Fernandez LE, Silman MR, Kane MJ, Sanders JW. Impairment in Working Memory and Executive Function Associated with Mercury Exposure in Indigenous Populations in Upper Amazonian Peru. Int J Environ Res Public Health 2022; 19:10989. [PMID: 36078698 PMCID: PMC9517927 DOI: 10.3390/ijerph191710989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/19/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
The Matsigenka people living traditional lifestyles in remote areas of the Amazon rely on a fish-based diet that exposes them to methylmercury (MeHg) at levels that have been associated with decreased IQ scores. In this study, the association between Hg levels and working memory was explored using the framework of the Multicomponent Model. Working memory tasks were modified to fit the culture and language of the Matsigenka when needed and included measures for verbal storage (Word Span) visuospatial storage (Corsi Block Task) and a measure of executive functions, the Self-Ordered Pointing Task (SOPT). An innovation of the Trail Making Tests A & B (TMT A & B) was pilot tested as another potential measure of executive functions. The mean hair Hg levels of 30 participants, ages 12 to 55 years, from three different communities (Maizal, Cacaotal and Yomibato) was 7.0 ppm (sd = 2.40), well above the World Health Organization (WHO) limit for hair of 2.0 ppm and ranged from 1.8 to 14.2 ppm, with 98% of a broader sample of 152 individuals exceeding the WHO limit. Hair Hg levels showed significant associations with cognitive performance, but the degree varied in magnitude according to the type of task. Hg levels were negatively associated with executive functioning performance (SOPT errors), while Hg levels and years of education predicted visuospatial performance (Corsi Block accuracy). Education was the only predictor of Word Span accuracy. The results show that Hg exposure is negatively associated with working memory performance when there is an increased reliance on executive functioning. Based on our findings and the review of the experimental research, we suggest that the SOPT and the Corsi Block have the potential to be alternatives to general intelligence tests when studying remote groups with extensive cultural differences.
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Affiliation(s)
- Alycia K. Silman
- Department of Psychology, Wake Forest University, Winston-Salem, NC 27109, USA
- Center for Energy, Environment, and Sustainability, Wake Forest University, Winston-Salem, NC 27109, USA
| | | | | | - Leahanne Giffin
- Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | | | - Katherine Myers
- Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Carlos Culquichicón
- Emerge, Emerging Diseases and Climate Change Research Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia (UPCH), San Martin de Porres 15102, Peru
| | - Stephanie Montero
- Emerge, Emerging Diseases and Climate Change Research Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia (UPCH), San Martin de Porres 15102, Peru
| | - Andres G. Lescano
- Emerge, Emerging Diseases and Climate Change Research Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia (UPCH), San Martin de Porres 15102, Peru
| | - Claudia M. Vega
- Centro de Innovación Científica Amazónica, Puerto Maldonado 17001, Peru
| | - Luis E. Fernandez
- Center for Energy, Environment, and Sustainability, Wake Forest University, Winston-Salem, NC 27109, USA
- Centro de Innovación Científica Amazónica, Puerto Maldonado 17001, Peru
- Department of Biology, Wake Forest University, Winston Salem, NC 27109, USA
- Carnegie Amazon Mercury Project, Department of Global Ecology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA
| | - Miles R. Silman
- Center for Energy, Environment, and Sustainability, Wake Forest University, Winston-Salem, NC 27109, USA
- Department of Biology, Wake Forest University, Winston Salem, NC 27109, USA
| | - Michael J. Kane
- Department of Psychology, University of North Carolina at Greensboro, Greensboro, NC 27412, USA
| | - John W. Sanders
- Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
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4
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Li X, Pan J, Wei Y, Ni L, Xu B, Deng Y, Yang T, Liu W. Mechanisms of oxidative stress in methylmercury-induced neurodevelopmental toxicity. Neurotoxicology 2021; 85:33-46. [PMID: 33964343 DOI: 10.1016/j.neuro.2021.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/02/2021] [Accepted: 05/03/2021] [Indexed: 12/15/2022]
Abstract
Methylmercury (MeHg) is a long-lasting organic environmental pollutant that poses a great threat to human health. Ingestion of seafood containing MeHg is the most important way by which it comes into contact with human body, where the central nervous system (CNS) is the primary target of MeHg toxicity. During periods of pre-plus postnatal, in particular, the brain of offspring is vulnerable to specific developmental insults that result in abnormal neurobehavioral development, even without symptoms in mothers. While many studies on neurotoxic effects of MeHg on the developing brain have been conducted, the mechanisms of oxidative stress in MeHg-induced neurodevelopmental toxicity is less clear. Hitherto, no single process can explain the many effects observed in MeHg-induced neurodevelopmental toxicity. This review summarizes the possible mechanisms of oxidative stress in MeHg-induced neurodevelopmental toxicity, highlighting modulation of Nrf2/Keap1/Notch1, PI3K/AKT, and PKC/MAPK molecular pathways as well as some preventive drugs, and thus contributes to the discovery of endogenous and exogenous molecules that can counteract MeHg-induced neurodevelopmental toxicity.
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Feng L, Zhang C, Liu H, Li P, Hu X, Wang H, Chan HM, Feng X. Impact of low-level mercury exposure on intelligence quotient in children via rice consumption. Ecotoxicol Environ Saf 2020; 202:110870. [PMID: 32593806 DOI: 10.1016/j.ecoenv.2020.110870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/27/2020] [Accepted: 06/06/2020] [Indexed: 06/11/2023]
Abstract
Wanshan is a city in southwest China that has several inactive mercury (Hg) mines. The local population are exposed to methylmercury (MeHg) due to the consumption of Hg contaminated rice. The relationship between Hg exposure and the cognitive functions of local children is unknown. This study investigated the relationship between hair Hg concentrations and the intelligence quotient (IQ) of 314 children aged 8-10 years, recruited from three local primary schools in Wanshan area in 2018 and 2019. IQ was evaluated using Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV). The average THg concentration in children's hair samples was 1.53 μg g-1 (range: 0.21-12.6 μg g-1), and 65.6% exceeded the United States Environment Protection Agency (USEPA) recommended value of 1 μg g-1. Results of logistic regression analysis showed that children with hair Hg ≥ 1 μg g-1 were 1.58 times more likely to have an IQ score <80, which is the clinical cut-off for borderline intellectual disability (R2 = 0.20, p = 0.03). Increasing of 1 μg g-1 hair Hg resulted in 1 point of IQ loss in Wanshan children, which was.much higher than that via fish consumption. The economical cost due to Hg exposure was estimated to be $69.8 million (9.43% of total GDP) in the Wanshan area in 2018.
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Affiliation(s)
- Lin Feng
- School of Public Health/Key Laboratory of Environmental Pollution Monitoring and Disease Control, Guizhou Medical University, Guiyang, 550025, China
| | - Chanchan Zhang
- School of Public Health/Key Laboratory of Environmental Pollution Monitoring and Disease Control, Guizhou Medical University, Guiyang, 550025, China
| | - Haohao Liu
- School of Public Health/Key Laboratory of Environmental Pollution Monitoring and Disease Control, Guizhou Medical University, Guiyang, 550025, China
| | - Ping Li
- School of Public Health/Key Laboratory of Environmental Pollution Monitoring and Disease Control, Guizhou Medical University, Guiyang, 550025, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
| | - Xuefeng Hu
- Department of Biology, University of Ottawa, Ottawa, K1N 6N5, Canada
| | - Huiqun Wang
- School of Public Health/Key Laboratory of Environmental Pollution Monitoring and Disease Control, Guizhou Medical University, Guiyang, 550025, China
| | - Hing Man Chan
- Department of Biology, University of Ottawa, Ottawa, K1N 6N5, Canada
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
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Al-Saleh I, Moncari L, Jomaa A, Elkhatib R, Al-Rouqi R, Eltabache C, Al-Rajudi T, Alnuwaysir H, Nester M, Aldhalaan H. Effects of early and recent mercury and lead exposure on the neurodevelopment of children with elevated mercury and/or developmental delays during lactation: A follow-up study. Int J Hyg Environ Health 2020; 230:113629. [PMID: 32956901 DOI: 10.1016/j.ijheh.2020.113629] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 02/07/2023]
Abstract
This follow-up study of 82 children investigated the potential impact of early and recent exposure to mercury and lead on their neurodevelopmental performance at 5-8 years of age (2017-2018). Early exposure of these children to mercury, methylmercury, and lead was assessed during lactation at 3-12 months old, as well as their mother's exposure using measurements from a cross-sectional study (2011-2013). Only infants who failed to pass the neurodevelopment screening tools and/or had elevated mercury were included in this study. Urine and hair were sampled during the follow-up study to assess the children's recent exposure to mercury, methylmercury, and lead. Their cognitive performance and visual-motor integration were also measured using the Test of Non-Verbal Intelligence (TONI) and the Beery-Visual-Motor Integration (Beery VMI), respectively. The association between alterations in urinary porphyrins excretion and exposure to metals was analyzed and their influence on the children's neurodevelopment was explored. Linear regression models revealed a significant negative association between the infants' mercury exposure during lactation and the TONI Quotient (β = -0.298, 95%CI = -4.677, -0.414) and Beery VMI Age Equivalent scores at age 5-8 (β = -0.437, 95%CI = -6.383, -1.844). The mothers' blood methylmercury was inversely and significantly associated with their children's TONI Quotient (β = -0.231, 95%CI = -8.184, -0.331). In contrast, the children's Beery VMI Age Equivalent scores were positively and significantly associated with the hair methylmercury of the mothers (β = 0.214, 95%CI = 0.088, 3.899) and their infants (β = 0.256, 95%CI = 0.396, 4.488). These relationships suggest the presence of negative confounding that we did not take into account. Unlike mercury, there was some evidence that lead in breast milk had an inverse relationship with the children's visual-motor coordination skills. Our study did not show a clear association between children's recent exposure to metals and neurodevelopment. However, a significant inverse association was observed between the TONI Quotient and the interaction of hair methylmercury × ∑porphyrins (ß = -0.224, 95%CI = -0.86, -0.049), implying that porphyrins are a sensitive measure of low body-mercury burden. Although lead induced higher ∑porphyrins excretion in urine (β = 0.347, 95%CI = 0.107, 0.525), their interaction did not influence children's neurodevelopmental scores. The interactions between metals and porphyrins might provide insights into their potential contributory role in the pathogenesis associated with neurological disorders or other diseases. Despite the small sample size of the present study, its findings about the association between toxic metal exposure and the high risk of poor neurodevelopmental performance are worrying, particularly at an early age, and additional research is needed using larger sample sizes.
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Affiliation(s)
| | | | - Ahmed Jomaa
- Center for Autism Research, King Faisal Specialist Hospital and Research Centre, P.O. Box: 3354, Riyadh, 11211, Saudi Arabia
| | | | | | | | | | | | | | - Hesham Aldhalaan
- Center for Autism Research, King Faisal Specialist Hospital and Research Centre, P.O. Box: 3354, Riyadh, 11211, Saudi Arabia
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Santos-Lima CD, Mourão DDS, Carvalho CFD, Souza-Marques B, Vega CM, Gonçalves RA, Argollo N, Menezes-Filho JA, Abreu N, Hacon SDS. Neuropsychological Effects of Mercury Exposure in Children and Adolescents of the Amazon Region, Brazil. Neurotoxicology 2020; 79:48-57. [PMID: 32335201 DOI: 10.1016/j.neuro.2020.04.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Studies with children exposed to methylmercury (MeHg) through fish consumption in the Brazilian Amazon region report that the high levels of hair Hg are associated with significant decreases in intelligence, memory, attention, and visuospatial processing. OBJECTIVE To investigate the relationship between mercury exposure and neuropsychological functions in riverside communities of the Brazilian Amazon. METHOD 263 participants aged 6 to 14 years old were assessed, from resettlement regions, near the Madeira river, Rondônia, Brazil. To assess the neuropsychological functions we used the following instruments: intelligence (WASI), working memory (Corsi Block-Tapping Task and Digit Span), verbal fluency (Word Generation - NEPSY II), inhibitory control (Inhibition Errors - NEPSY II), shifting (Trail Making Test) and manual motor dexterity (Grooved PegBoard Test). Socioeconomic status was obtained through household surveys. Total Hg levels were quantified hair samples (Total HgH) collected from the occipital region of the scalp and analyzed by Cold Vapor Atomic Absorption Spectrometry. RESULTS The group in the upper quartile of Total HgH levels presented lower scores on the tasks that assessed estimated IQ, visuospatial working memory, semantic knowledge and phonological verbal fluency, when compared to the group in the lower quartile level. A regression analysis controlled for age, sex, and maternal education showed that for each increase of 10 μg/g of Total HgH, there was a decrease around half standard deviation in Verbal IQ, estimated IQ scores, semantic knowledge, phonological verbal fluency and for verbal and visuospatial working memory. CONCLUSIONS High concentrations of Total Hg in hair were associated with a lower performance in neuropsychological functions tests. The results show that environmental exposure to Hg is associated to children and adolescents' lower neuropsychological performance in the riverine and resettled areas of the Brazilian Amazon region.
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Affiliation(s)
- Cassio Dos Santos-Lima
- Clinical and Cognitive Neuropsychology Research Laboratory, Institute of Psychology, Federal University of Bahia, Bahia, Brazil; Graduate Program in Psychology, Institute of Psychology, Federal University of Bahia, Bahia, Brazil.
| | - Dennys de Souza Mourão
- Graduate Program in Environmental Engineering, Federal University of Espírito Santo, Espírito Santo, Brazil
| | - Chrissie Ferreira de Carvalho
- Clinical and Cognitive Neuropsychology Research Laboratory, Institute of Psychology, Federal University of Bahia, Bahia, Brazil; Department of Psychology, Federal University of Santa Catarina, Santa Catarina, Brazil
| | - Breno Souza-Marques
- Clinical and Cognitive Neuropsychology Research Laboratory, Institute of Psychology, Federal University of Bahia, Bahia, Brazil; Graduate Program in Medicine and Health, Faculty of Medicine, Federal University of Bahia, Bahia, Brazil
| | - Cláudia M Vega
- Graduate Program in Public Health and Environment, National School of Public Health Sergio Arouca, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; Center for Amazonian Scientific Innovation, Wake Forest University, Madre de Dios, Peru
| | | | - Nayara Argollo
- Department of Pediatry, Faculty of Medicine, Federal University of Bahia, Bahia, Brazil
| | | | - Neander Abreu
- Clinical and Cognitive Neuropsychology Research Laboratory, Institute of Psychology, Federal University of Bahia, Bahia, Brazil; Graduate Program in Psychology, Institute of Psychology, Federal University of Bahia, Bahia, Brazil
| | - Sandra de Souza Hacon
- Graduate Program in Public Health and Environment, National School of Public Health Sergio Arouca, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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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. Handb Clin Neurol 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: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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9
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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. Environ Res 2019; 177:108641. [PMID: 31421445 DOI: 10.1016/j.envres.2019.108641] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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Soler-Blasco R, Murcia M, Lozano M, Aguinagalde X, Iriarte G, Lopez-Espinosa MJ, Vioque J, Iñiguez C, Ballester F, Llop S. Exposure to mercury among 9-year-old Spanish children: Associated factors and trend throughout childhood. Environ Int 2019; 130:104835. [PMID: 31226565 DOI: 10.1016/j.envint.2019.05.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/11/2019] [Accepted: 05/11/2019] [Indexed: 06/09/2023]
Abstract
Mercury is considered a neurotoxicant and human exposure occurs mainly from the consumption of marine species. We aimed to describe total mercury concentrations (THg) and associated factors in 9-year old children, as well as to explore the trend in THg from 4 to 9 years of age. The study population consisted of 9-year-old children participating in the INMA (Environment and Childhood) birth cohort study in Valencia, Spain (n = 405, 2013-2014). THg in hair samples was measured by atomic absorption spectrometry at the age of 4 and 9 years. Sociodemographic and dietary data was obtained through questionnaires. Multiple linear regression was used to explore the association between THg and covariates. The geometric mean (95% confidence interval) of hair THg at 9 years old was 0.89 μg/g (0.81, 0.98). Thirteen percent of children had THg above the equivalent to the Provisional Tolerable Weekly Intake proposed by the World Health Organization. THg were higher among children whose mothers had a healthy body mass index before pregnancy. Children with non-smoker mothers and worker fathers had also higher THg. Children's fish intake at 9 years-old was positively associated with THg, being swordfish, canned tuna and lean fish (i.e. hake, sea bream and sole) the most associated categories. Levels decreased by around 22% between 4 and 9 years old. Birth cohort studies, such as the INMA Project, allow the longitudinal evaluation of Hg exposure and the possible effects on children's health. This information can be used to formulate diet recommendations in vulnerable populations.
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Affiliation(s)
- Raquel Soler-Blasco
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Mario Murcia
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Manuel Lozano
- Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Spain
| | - Xabier Aguinagalde
- Public Health Laboratory in Alava, Santiago 11, 01002 Vitoria Gasteiz, Spain
| | - Gorka Iriarte
- Public Health Laboratory in Alava, Santiago 11, 01002 Vitoria Gasteiz, Spain
| | - Maria-Jose Lopez-Espinosa
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Department of Nursing and Chiropody, Universitat de València, Valencia, Spain
| | - Jesús Vioque
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Universidad Miguel Hernandez, ISABIAL-FISABIO, Sant Joan d'Alacant, Spain
| | - Carmen Iñiguez
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Department of Statistics and Computational Research, Universitat de València, Valencia, Spain
| | - Ferran Ballester
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Department of Nursing and Chiropody, Universitat de València, Valencia, Spain
| | - Sabrina Llop
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
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11
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Delplancke TDJ, Wu Y, Han TL, Joncer LR, Qi H, Tong C, Baker PN. Metabolomics of Pregnancy Complications: Emerging Application of Maternal Hair. Biomed Res Int 2018; 2018:2815439. [PMID: 30662903 PMCID: PMC6312607 DOI: 10.1155/2018/2815439] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/18/2018] [Indexed: 02/01/2023]
Abstract
In recent years, the study of metabolomics has begun to receive increasing international attention, especially as it pertains to medical research. This is due in part to the potential for discovery of new biomarkers in the metabolome and to a new understanding of the "exposome", which refers to the endogenous and exogenous compounds that reflect external exposures. Consequently, metabolomics research into pregnancy-related issues has increased. Biomarkers discovered through metabolomics may shed some light on the etiology of certain pregnancy-related complications and their adverse effects on future maternal health and infant development and improve current clinical management. The discoveries and methods used in these studies will be compiled and summarized within the following paper. A further focus of this paper is the use of hair as a biological sample, which is gaining increasing attention across diverse fields due to its noninvasive sampling method and the metabolome stability. Its significance in exposome studies will be considered in this review, as well as the potential to associate exposures with adverse pregnancy outcomes. Currently, hair has been used in only two metabolomics studies relating to fetal growth restriction (FGR) and gestational diabetes mellitus (GDM).
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Affiliation(s)
- Thibaut D. J. Delplancke
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, Chongqing Medical University, Chongqing 400016, China
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
| | - Yue Wu
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, Chongqing Medical University, Chongqing 400016, China
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
| | - Ting-Li Han
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, Chongqing Medical University, Chongqing 400016, China
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
- Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Lingga R. Joncer
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
| | - Hongbo Qi
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, Chongqing Medical University, Chongqing 400016, China
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
| | - Chao Tong
- Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, Chongqing Medical University, Chongqing 400016, China
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
| | - Philip N. Baker
- International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
- Liggins Institute, University of Auckland, Auckland, New Zealand
- College of Medicine, University of Leicester, Leicester LE1 7RH, UK
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12
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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: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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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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Sobolewski M, Conrad K, Marvin E, Allen JL, Cory-Slechta DA. Endocrine active metals, prenatal stress and enhanced neurobehavioral disruption. Horm Behav 2018; 101:36-49. [PMID: 29355495 PMCID: PMC5970043 DOI: 10.1016/j.yhbeh.2018.01.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/05/2018] [Accepted: 01/14/2018] [Indexed: 11/24/2022]
Abstract
Metals, including lead (Pb), methylmercury (MeHg) and arsenic (As), are long-known developmental neurotoxicants. More recently, environmental context has been recognized to modulate metals toxicity, including nutritional state and stress exposure. Modulation of metal toxicity by stress exposure can occur through shared targeting of endocrine systems, such as the hypothalamic-pituitary-adrenal axis (HPA). Our previous rodent research has identified that prenatal stress (PS) modulates neurotoxicity of two endocrine active metals (EAMs), Pb and MeHg, by altering HPA and CNS systems disrupting behavior. Here, we review this research and further test the hypothesis that prenatal stress modulates metals neurotoxicity by expanding to test the effect of developmental As ± PS exposure. Serum corticosterone and behavior was assessed in offspring of dams exposed to As ± PS. PS increased female offspring serum corticosterone at birth, while developmental As exposure decreased adult serum corticosterone in both sexes. As + PS induced reductions in locomotor activity in females and reduced response rates on a Fixed Interval schedule of reinforcement in males, with the latter suggesting unique learning deficits only in the combined exposure. As-exposed males showed increased time in the open arms of an elevated plus maze and decreased novel object recognition whereas females did not. These data further confirm the hypothesis that combined exposure to chemical (EAMs) and non-chemical (PS) stressors results in enhanced neurobehavioral toxicity. Given that humans are exposed to multiple environmental risk factors that alter endocrine function in development, such models are critical for risk assessment and public health protection, particularly for children.
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Affiliation(s)
- Marissa Sobolewski
- Dept. of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY, United States. marissa:
| | - Katherine Conrad
- Dept. of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY, United States
| | - Elena Marvin
- Dept. of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY, United States
| | - Joshua L Allen
- Dept. of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY, United States
| | - Deborah A Cory-Slechta
- Dept. of Environmental Medicine, University of Rochester School of Medicine, Rochester, NY, United States
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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. Environ Int 2017; 102:97-105. [PMID: 28216013 DOI: 10.1016/j.envint.2017.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Zeng X, Xu X, Boezen HM, Huo X. Children with health impairments by heavy metals in an e-waste recycling area. Chemosphere 2016; 148:408-15. [PMID: 26829309 DOI: 10.1016/j.chemosphere.2015.10.078] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 10/10/2015] [Accepted: 10/19/2015] [Indexed: 02/05/2023]
Abstract
E-waste recycling has become a global environmental health issue. Pernicious chemicals escape into the environment due to informal and nonstandard e-waste recycling activities involving manual dismantling, open burning to recover heavy metals and open dumping of residual fractions. Heavy metals derived from electronic waste (e-waste), such as, lead (Pb), cadmium (Cd), chromium (Cr), manganese (Mn), nickel (Ni), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), aluminum (Al) and cobalt (Co), differ in their chemical composition, reaction properties, distribution, metabolism, excretion and biological transmission. Our previous studies showed that heavy metal exposure have adverse effects on children's health including lower birth weight, lower anogenital distance, lower Apgar scores, lower current weight, lower lung function, lower hepatitis B surface antibody levels, higher prevalence of attention-deficit/hyperactivity disorder, and higher DNA and chromosome damage. Heavy metals influence a number of diverse systems and organs, resulting in both acute and chronic effects on children's health, ranging from minor upper respiratory irritation to chronic respiratory, cardiovascular, nervous, urinary and reproductive disease, as well as aggravation of pre-existing symptoms and disease. These effects of heavy metals on children's health are briefly discussed.
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Affiliation(s)
- Xiang Zeng
- Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou University, 22 Xinling Road, Shantou 515041, China; Department of Epidemiology, University Medical Center Groningen, University of Groningen, 1 Hanzeplein, Groningen 9700RB, The Netherlands; Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of Groningen, 1 Hanzeplein, Groningen 9700RB, The Netherlands
| | - Xijin Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou University, 22 Xinling Road, Shantou 515041, China; Department of Cell Biology and Genetics, Shantou University Medical College, Shantou University, 22 Xinling Road, Shantou 515041, China
| | - H Marike Boezen
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, 1 Hanzeplein, Groningen 9700RB, The Netherlands; Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of Groningen, 1 Hanzeplein, Groningen 9700RB, The Netherlands
| | - Xia Huo
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
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Ilmiawati C, Yoshida T, Itoh T, Nakagi Y, Saijo Y, Sugioka Y, Sakamoto M, Ikegami A, Ogawa M, Kayama F. Biomonitoring of mercury, cadmium, and lead exposure in Japanese children: a cross-sectional study. Environ Health Prev Med 2015; 20:18-27. [PMID: 25293698 DOI: 10.1007/s12199-014-0416-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/18/2014] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVES To measure current Hg, Cd, and Pb exposure in Japanese children, and to estimate dietary intakes of foods responsible for high body burden. METHODS Blood, hair, and urine samples were collected from 9 to 10-year-old 229 children in Asahikawa and measured for Hg, Cd, and Pb in these matrices. Diet history questionnaire was used to estimate intake of marine foods and other food items. Hg level was measured by cold vapor atomic absorption spectrometry. Cd and Pb levels were determined with inductively coupled plasma mass spectrometry. RESULTS Geometric mean (GM) of blood Hg, Cd, and Pb was 4.55 μg/L, 0.34 μg/L, and 0.96 μg/dL, respectively. Urinary Cd level was 0.34 μg/g creatinine (GM) and hair Hg was 1.31 μg/g (GM). Approximately one-third (35%) of blood samples had Hg level above the U.S. EPA reference dose (RfD; 5.8 μg/L). Hair Hg level exceeded U.S. EPA RfD (1.2 μg/g) in 59 % samples. Children in the upper quartile of blood Hg level had significantly higher intake of large predatory fish species compared to those in the lower quartile of blood Hg. CONCLUSIONS Those with high blood Hg level may be explained by more frequent intake of big predatory fish. Cd and Pb exposure is generally low among Japanese children. As no safety margin exists for Pb exposure and high exposure to MeHg is noted in Japanese population; periodic biomonitoring and potential health risk assessment should continue in high-risk populations, notably among children.
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Dórea JG, Marques RC, Abreu L. Milestone achievement and neurodevelopment of rural Amazonian toddlers (12 to 24 months) with different methylmercury and ethylmercury exposure. J Toxicol Environ Health A 2014; 77:1-13. [PMID: 24555642 DOI: 10.1080/15287394.2014.861335] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Neurological outcomes (Gesell development schedules [GDS]), age of walking, and age of talking were studied in 299 toddlers (12 to 24 mo) in relation to environmental (fish consumption and tin mining) exposure. Exposure to fish methylmercury (MeHg) consumption and iatrogenic ethylmercury (EtHg) in Thimerosal-containing vaccines (TCV) was quantified in toddlers from two rural villages (n = 91, Itapuã; n = 218, Bom Futuro) respectively populated by fishers and cassiterite miners. Median total hair Hg (HHg) concentrations of infants from Itapuã (3.5 μg/g) were significantly higher than those of infants from Bom Futuro (2.2 μg/g). Median EtHg exposure from TCV was also significantly higher in toddlers from Itapuã (137.5 μg) than in those from Bom Futuro (112.5 μg). There were no significant differences between groups for any of the Gesell schedules; however, there were proportionally more compromised toddlers (GDS < 70) in Itapuã than Bom Futuro. Median age of talking was not statistically different but median age of walking was significantly higher in Bom Futuro. In toddlers from both villages, of fishers and miners, HHg concentrations were significantly correlated with family fish consumption. A logistic regression model was applied to all infants after classification into two groups: above or below the median Gesell schedules. Overall, there was no distinctive pattern of neurodevelopment associated with either HHg or EtHg exposure; however, nutritional status was significantly associated with GDS. In conclusion, milestone achievement was delayed in toddlers from tin-ore mining communities. Despite significantly higher exposure to both forms of organic Hg (MeHg from maternal fish consumption, and EtHg from TCV) in toddlers from the fishing village, significant differences were seen only among the proportions of most severely affected toddlers (GDS < 70).
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Affiliation(s)
- José G Dórea
- a Department of Nutrition , Universidade de Brasília , Brasília , Brazil
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