1
|
Crépet A, Vasseur P, Jean J, Badot PM, Nesslany F, Vernoux JP, Feidt C, Mhaouty-Kodja S. Integrating Selection and Risk Assessment of Chemical Mixtures: A Novel Approach Applied to a Breast Milk Survey. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:35001. [PMID: 35238606 PMCID: PMC8893236 DOI: 10.1289/ehp8262] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 06/01/2023]
Abstract
BACKGROUND One of the main challenges of modern risk assessment is to account for combined exposure to the multitude of various substances present in food and the environment. OBJECTIVE The present work proposes a methodological approach to perform chemical risk assessment of contaminant mixtures across regulatory silos regarding an extensive range of substances and to do so when comprehensive relevant data concerning the specific effects and modes of action of the mixture components are not available. METHODS We developed a complete step-by-step approach using statistical methods to prioritize substances involved in combined exposure, and we used a component-based approach to cumulate the risk using dose additivity. The most relevant toxicological end point and the associated reference point were selected from the literature to construct a toxicological threshold for each substance. DISCUSSION By applying the proposed method to contaminants in breast milk, we observed that among the 19 substances comprising the selected mixture, ∑DDT, ∑PCBi, and arsenic were main joint contributors to the risk of neurodevelopmental and thyroid effects for infants. In addition, ∑PCCD/F contributed to the thyroid effect and ∑aldrin-dieldrin to the neurodevelopmental effect. Our case study on contaminants in breast milk demonstrated the importance of crossing regulatory silos when studying mixtures and the importance of identifying risk drivers to regulate the risk related to environmental contamination. Applying this method to another set of data, such as human biomonitoring or in ecotoxicology, will reinforce its relevance for risk assessment. https://doi.org/10.1289/EHP8262.
Collapse
Affiliation(s)
- Amélie Crépet
- Methodology and Studies Unit, Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Paule Vasseur
- Université de Lorraine, Centre national de la recherche scientifique (CNRS), Laboratoire Interdisciplinaire des Environnements Continentaux, Metz, France
| | - Julien Jean
- Methodology and Studies Unit, Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Pierre-Marie Badot
- Chrono-Environment Department, Franche-Comté University, CNRS, Besançon, France
| | - Fabrice Nesslany
- Université de Lille, Centre Hospitalier Universitaire de Lille, Institut Pasteur de Lille, EA4483-IMPacts de l’Environnement Chimique sur la Santé Humaine, Lille, France
- Laboratoire de Toxicologie Génétique, Institut Pasteur de Lille, Lille, France
| | - Jean-Paul Vernoux
- Université de Caen Normandie, Unité de Recherche Aliments Bioprocédés Toxicologie Environnements, EA4651, Caen, France
| | - Cyril Feidt
- Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux, Nancy, France
| | - Sakina Mhaouty-Kodja
- Sorbonne Université, CNRS, Institut national de la santé et de la recherche médicale, Neuroscience Paris Seine—Institut de Biologie Paris Seine, Paris, France
| |
Collapse
|
2
|
Zhou CC, Fu H, Zhang GY, Ma JW, Ni M, Li DJ, Shen FM, Huang F. Effects of low-level mercury exposure on brain-derived neurotrophic factor in preschool children. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111642. [PMID: 33396162 DOI: 10.1016/j.ecoenv.2020.111642] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/04/2020] [Accepted: 11/08/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVES Mercury (Hg), a ubiquitous heavy metal, could affect the neurodevelopment of the children, however, these associations are still equivocal. Brain derived neurotrophic factor (BDNF) plays an essential role in the central nervous system development in children. This study aimed to investigate the effects of low-level mercury exposure on serum BDNF levels and the influence of sex and dietary intake on these relationships in children. METHODS In this cross-sectional study, a total of 541 pre-school children were recruited, the blood mercury concentrations and serum BDNF levels were measured. The background information on demographic characteristics and dietary habits of the children was collected through questionnaires. Multivariable linear models after adjustment for potential confounders were used to evaluate the associations between mercury exposure and levels of BDNF in children. RESULTS The GMs of blood mercury concentrations and serum BDNF levels were 1.06 μg/L, 20.4 ng/mL, respectively. A significant positive association between blood mercury concentrations and serum BDNF levels was found. After stratification by sex, the blood mercury concentrations in children were positive associated with serum BDNF levels in girls but not in boys. However, these associations were attenuated when we further adjusted the children's dietary intake variables. CONCLUSIONS Our findings suggest that low-levels of mercury exposure may have sex-specific effects on BDNF levels in young children and that dietary intake may be potential confounders in these relationships. However, further studies are warranted to investigate the role of BDNF in the effects of mercury on neurodevelopment.
Collapse
Affiliation(s)
- Can-Can Zhou
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hui Fu
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Guo-Yan Zhang
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jia-Wei Ma
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Min Ni
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Dong-Jie Li
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Fu-Ming Shen
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Fang Huang
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| |
Collapse
|
3
|
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: 3] [Impact Index Per Article: 0.8] [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.
Collapse
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.
| |
Collapse
|
4
|
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: 0.8] [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.
Collapse
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.
| |
Collapse
|
5
|
Mercury Exposure, Fish Consumption, and Perceived Risk among Pregnant Women in Coastal Florida. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16244903. [PMID: 31817296 PMCID: PMC6949990 DOI: 10.3390/ijerph16244903] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 12/21/2022]
Abstract
Seafood consumption is the primary source of mercury (Hg) exposure, particularly among coastal populations. Hg exposure during pregnancy has been associated with cognitive impairment, as well as decrements in memory, attention, fine motor skills, and other markers of delayed neurodevelopment, although results are conflicting. High Hg hair concentrations in persons from coastal Florida, USA, have been previously reported. The purpose of the current study was to determine the concentrations of total Hg (THg) in the hair of pregnant women from this area and to assess the relationships between THg concentration, knowledge of the risks of mercury exposure, and dietary patterns among participants. Participants (n = 229) were recruited at prenatal clinics. Their mean total hair Hg concentration was 0.31 + 0.54 µg/g, lower or similar to US data for women of child-bearing age. Hair THg concentration was associated with consumption of locally caught fish and all seafood, a higher level of education, and first pregnancy. Eighty-five percent of women were aware of the risks of mercury exposure during pregnancy; over half reported a decrease in seafood consumption during pregnancy. Awareness of Hg in fish was marginally associated with lower hair THg concentration (p = 0.06) but reduction in seafood consumption during pregnancy was not.
Collapse
|
6
|
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: 1.6] [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.
Collapse
|
7
|
Prince LM, Aschner M, Bowman AB. Human-induced pluripotent stems cells as a model to dissect the selective neurotoxicity of methylmercury. Biochim Biophys Acta Gen Subj 2019; 1863:129300. [PMID: 30742955 DOI: 10.1016/j.bbagen.2019.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 01/09/2019] [Accepted: 02/01/2019] [Indexed: 01/07/2023]
Abstract
Methylmercury (MeHg) is a potent neurotoxicant affecting both the developing and mature central nervous system (CNS) with apparent indiscriminate disruption of multiple homeostatic pathways. However, genetic and environmental modifiers contribute significant variability to neurotoxicity associated with human exposures. MeHg displays developmental stage and neural lineage selective neurotoxicity. To identify mechanistic-based neuroprotective strategies to mitigate human MeHg exposure risk, it will be critical to improve our understanding of the basis of MeHg neurotoxicity and of this selective neurotoxicity. Here, we propose that human-based pluripotent stem cell cellular approaches may enable mechanistic insight into genetic pathways that modify sensitivity of specific neural lineages to MeHg-induced neurotoxicity. Such studies are crucial for the development of novel disease modifying strategies impinging on MeHg exposure vulnerability.
Collapse
Affiliation(s)
- Lisa M Prince
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, United States.
| |
Collapse
|
8
|
Barbone F, Rosolen V, Mariuz M, Parpinel M, Casetta A, Sammartano F, Ronfani L, Vecchi Brumatti L, Bin M, Castriotta L, Valent F, Little DL, Mazej D, Snoj Tratnik J, Miklavčič Višnjevec A, Sofianou K, Špirić Z, Krsnik M, Osredkar J, Neubauer D, Kodrič J, Stropnik S, Prpić I, Petrović O, Vlašić-Cicvarić I, Horvat M. Prenatal mercury exposure and child neurodevelopment outcomes at 18 months: Results from the Mediterranean PHIME cohort. Int J Hyg Environ Health 2018; 222:9-21. [PMID: 30057028 DOI: 10.1016/j.ijheh.2018.07.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 07/13/2018] [Accepted: 07/19/2018] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Neurotoxicity due to acute prenatal exposure to high-dose of mercury (Hg) is well documented. However, the effect of prenatal exposure to low Hg levels on child neurodevelopment and the question about "safety" of fish-eating during pregnancy remain controversial. International comparisons of Hg concentrations in mother-child biological samples and neurodevelopmental scores embedded in birth cohort studies may provide useful evidence to explore this issue. MATERIALS AND METHODS The Mediterranean (Italy, Slovenia, Croatia, and Greece) cohort study included 1308 mother-child pairs enrolled in the Public Health Impact of long-term, low-level, Mixed Element exposure in a susceptible population EU Sixth Framework Programme (PHIME). Maternal hair and venous blood, cord blood and breast milk samples were collected, and total Hg (THg) levels were measured. Demographic and socioeconomic information, lifestyles and nutritional habits were collected through questionnaires at different phases of follow-up. Children at 18 months of age underwent neurodevelopmental testing using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Multivariate linear and logistic regressions were performed, for each country, to assess the association between THg and BSID-III scores, obtaining adjusted β coefficients and odds ratios (ORs). These values were used to conduct a meta-analysis, to explore possible heterogeneity among countries and to obtain combined estimates of the association between THg exposure and BSID-III scores. RESULTS Median THg (ng/g) was: 704 in maternal hair, 2.4 in maternal blood, 3.6 in cord blood, and 0.6 in breast milk. THg concentrations were highest in Greece and lowest in Slovenia. BSID-III neurodevelopmental scores were higher in Croatia and Slovenia. The meta-analysis of multivariate linear models found an overall positive association between language composite score and receptive communication scaled score and increasing THg in maternal hair (n = 1086; β = 0.55; 95%CI: 0.05-1.05 and n = 1075; β = 0.12; 95%CI: 0.02-0.22, respectively). The meta-analysis of logistic regression models showed that the overall adjusted OR between THg in cord blood and suboptimal gross motor score was borderline significant (n = 882; OR = 1.03; 95%CI: 1.00-1.07). Heterogeneity was found across the four sub-cohorts for language composite score in maternal blood, and for fine motor scaled score in cord blood and breast milk. Language composite score and THg concentrations in maternal venous blood were positively related (n = 58; β = 4.29; CI95% (-0.02, 8.60)) in Croatia and an increase of 1 ng/g of THg in maternal venous blood was associated with a reduced risk for children to fall in the lowest quintile of language score by 31% (n = 58; OR = 0.69; CI 95%: 0.37, 1.01). The comparison of β coefficients obtained by multiple linear regression model showed an inverse association between fine motor score and THg concentrations in cord blood for Croatia (n = 54; β = -0.53; CI 95%: -1.10, 0.04) and Slovenia (n = 225; β = -0.25; CI 95%: -0.49, -0.01). In Slovenia THg level in breast milk was associated with suboptimal fine motor performance (n = 195; OR = 5.25; CI 95%: 1.36, 21.10). CONCLUSIONS This study showed an inverse relation between THg levels and developmental motor scores at 18 months, although the evidence was weak and partially internally and externally inconsistent. No evidence of detrimental effects of THg was found for cognitive and language outcomes at these concentrations and age.
Collapse
Affiliation(s)
- Fabio Barbone
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", via dell'Istria, 65/1, 34137, Trieste, Italy.
| | - Valentina Rosolen
- Department of Medical Area, University of Udine, via Colugna 50, 33100, Udine, Italy.
| | - Marika Mariuz
- Department of Medical Area, University of Udine, via Colugna 50, 33100, Udine, Italy.
| | - Maria Parpinel
- Department of Medical Area, University of Udine, via Colugna 50, 33100, Udine, Italy.
| | - Anica Casetta
- Department of Medical Area, University of Udine, via Colugna 50, 33100, Udine, Italy.
| | - Francesca Sammartano
- Department of Medical Area, University of Udine, via Colugna 50, 33100, Udine, Italy.
| | - Luca Ronfani
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", via dell'Istria, 65/1, 34137, Trieste, Italy.
| | - Liza Vecchi Brumatti
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", via dell'Istria, 65/1, 34137, Trieste, Italy.
| | - Maura Bin
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", via dell'Istria, 65/1, 34137, Trieste, Italy.
| | - Luigi Castriotta
- Institute of Hygiene and Clinical Epidemiology Academic Hospital of Udine, via Colugna 50, 33100, Udine, Italy.
| | - Francesca Valent
- Institute of Hygiene and Clinical Epidemiology Academic Hospital of Udine, via Colugna 50, 33100, Udine, Italy.
| | - D'Anna Latesha Little
- Azienda per I'Assistenza Sanitaria n. 5 Friuli Occidentale, via Piave 54 33170 Pordenone (PN), Italy.
| | - Darja Mazej
- Jozef Stefan Institute, Jamova 39 SI-1000, Ljubljana, Slovenia.
| | - Janja Snoj Tratnik
- Jozef Stefan Institute, Jamova 39 SI-1000, Ljubljana, Slovenia; International Postgraduate School Jozef Stefan, Jamova 39 SI-1000, Ljubljana, Slovenia.
| | | | - Katia Sofianou
- Institute of Child Health, "Aghia Sophia" Children's Hospital, Thivon & Papadiamantopoulou, Goudi, 115 27, Athens, Greece.
| | - Zdravko Špirić
- Green Infrastructure Ltd., Fallerovo Setaliste 22, 10.000, Zagreb, Croatia.
| | | | | | | | - Jana Kodrič
- University Medical Centre Ljubljana, Slovenia.
| | | | - Igor Prpić
- The Clinical Hospital Center of Rijeka, Krešimirova 42, 51000, Rijeka, Croatia.
| | - Oleg Petrović
- The Clinical Hospital Center of Rijeka, Krešimirova 42, 51000, Rijeka, Croatia.
| | | | - Milena Horvat
- Jozef Stefan Institute, Jamova 39 SI-1000, Ljubljana, Slovenia; International Postgraduate School Jozef Stefan, Jamova 39 SI-1000, Ljubljana, Slovenia.
| |
Collapse
|
9
|
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: 23] [Impact Index Per Article: 3.8] [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.
Collapse
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
| |
Collapse
|
10
|
Freire C, Amaya E, Gil F, Fernández MF, Murcia M, Llop S, Andiarena A, Aurrekoetxea J, Bustamante M, Guxens M, Ezama E, Fernández-Tardón G, Olea N. Prenatal co-exposure to neurotoxic metals and neurodevelopment in preschool children: The Environment and Childhood (INMA) Project. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:340-351. [PMID: 29190557 DOI: 10.1016/j.scitotenv.2017.11.273] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/06/2017] [Accepted: 11/24/2017] [Indexed: 05/04/2023]
Abstract
We sought to determine whether prenatal co-exposure to As, Cd, Hg, Mn, and Pb was associated with impaired neurodevelopment in preschool children from the Spanish Environment and Childhood (INMA) Project, using the placenta as exposure matrix. We measured metal levels in placenta tissue samples randomly selected from five of the seven population-based birth cohorts participating in the INMA Project, collected between 2000 and 2008. Neuropsychological assessment of cognitive and motor function was carried through the use of the McCarthy Scales of Children's Abilities (MSCA) at the age of 4-5years. Data on placental metal levels, MSCA scores, and relevant covariates was available for 302 children. Mn was detected in all placental samples, Cd in nearly all placentas (99%) and As, Hg, and Pb in 22%, 58%, and 17% of the placentas, respectively. After adjusting for potential confounders, detectable As levels were associated with decrements in global and verbal executive functions and quantitative abilities; detectable Hg was associated with lower scores on the verbal function of posterior cortex in a dose-response manner, and non-linearly related to poorer motor function and gross motor skills; and Mn levels were associated with decrement in perceptual-performance skills in a dose-response manner but with better memory span and quantitative skills. A synergistic interactive effect was found between As and Pb with respect to the general cognitive score, whereas an antagonistic interaction was found between Mn and Hg. Prenatal exposure to As and Hg may be a risk factor for cognitive and motor impairment in children, while the effects of Cd and Mn on neurodevelopment are less clear. Future studies should examine combined and interactive effects of exposure to multiple metals during vulnerable periods of brain development prospectively.
Collapse
Affiliation(s)
- Carmen Freire
- Health Research Institute of Granada (ibs.GRANADA), 18012 Granada, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain
| | - Esperanza Amaya
- Health Research Institute of Granada (ibs.GRANADA), 18012 Granada, Spain
| | - Fernando Gil
- Department of Legal Medicine, Toxicology, and Physical Anthropology, School of Medicine, University of Granada, 18071 Granada, Spain
| | - Mariana F Fernández
- Health Research Institute of Granada (ibs.GRANADA), 18012 Granada, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Radiology, School of Medicine, and Centre for Biomedical Research, University of Granada, 18071 Granada, Spain.
| | - Mario Murcia
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Jaume I University-University of Valencia, 46020 Valencia, Spain
| | - Sabrina Llop
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Jaume I University-University of Valencia, 46020 Valencia, Spain
| | - Ainara Andiarena
- BIODONOSTIA Health Research Institute, 20014 San Sebastián, Spain; University of the Basque Country (UPV/EHU), 20018 San Sebastián, Spain
| | - Juanjo Aurrekoetxea
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; BIODONOSTIA Health Research Institute, 20014 San Sebastián, Spain; Department of Preventive Medicine and Public Health, University of Basque Country (UPV/EHU), 48940 Leioa, Bizkaia, Spain; Subdirección de Salud Pública de Gipuzkoa, Department of Health of the Basque Government, 20013 San Sebastián, Spain
| | - Mariona Bustamante
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), 08036 Barcelona, Spain; Pompeu Fabra Universtiy (UPF), 08002 Barcelona, Spain; Genomics and Disease Group, Bioinformatics and Genomics Program, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain
| | - Mònica Guxens
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), 08036 Barcelona, Spain; Pompeu Fabra Universtiy (UPF), 08002 Barcelona, Spain; Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre-Sophia Children's Hospital, 3015 CN Rotterdam, Netherlands
| | - Esteban Ezama
- Cicom, Alternativa en Salud Mental, 33001 Oviedo, Spain
| | - Guillermo Fernández-Tardón
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Preventive Medicine and Public Health, School of Medicine, University of Oviedo, 33003 Oviedo, Spain
| | - Nicolás Olea
- Health Research Institute of Granada (ibs.GRANADA), 18012 Granada, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Radiology, School of Medicine, and Centre for Biomedical Research, University of Granada, 18071 Granada, Spain
| |
Collapse
|
11
|
Kim Y, Ha EH, Park H, Ha M, Kim Y, Hong YC, Lee EJ, Kim H, Chang N, Kim BN. Prenatal mercury exposure, fish intake and neurocognitive development during first three years of life: Prospective cohort mothers and Children's environmental health (MOCEH) study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 615:1192-1198. [PMID: 29751424 DOI: 10.1016/j.scitotenv.2017.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 09/28/2017] [Accepted: 10/03/2017] [Indexed: 06/08/2023]
Abstract
OBJECTIVES In this prospective cohort study, the effects of prenatal Hg exposure on neurocognitive development during the first 3years of life were investigated. METHODS The maternal blood levels of Hg were assessed during pregnancy and in cord blood. Maternal fish intake was assessed by interviewing the weekly frequency of fish intake during pregnancy. Maternal n-3 and n-6 fatty acid intake was estimated based on 24h recall food intake interview. The mental (MDI) and psychomotor (PDI) development index scores were assessed using the Bayley Scales of Infant Development at 6, 12, 24, 36months of age. RESULTS The geometric mean of the maternal blood Hg concentration was 3.3μg/L (10th percentile=1.81; 90th=5.91) during the early pregnancy, 3.0μg/L (10th=1.68; 90th=5.57) during late pregnancy, and 5.1μg/L (10th=2.94; 90th=8.93) in cord blood. After adjusting for weekly frequency of fish intake, the blood Hg concentrations during early pregnancy showed association with the adjusted MDI (β=-0.408, p=0.048) and PDI scores (β=-0.550, p=0.031) at 6months. After further adjusting for n-3 and n-6 fatty acids estimated based on 24h recall of food intake, the blood Hg concentrations during early pregnancy showed association with the MDI (β=-0.489, p=0.026) and PDI (β=-0.664, p=0.015) at 6months. CONCLUSION These results show that prenatal Hg exposure during early pregnancy adversely associated with early neurodevelopment during infancy, after adjusting for fish and n-3, n-6 fatty acid intake. Consuming fish high in fatty acids and low in Hg during early pregnancy may be important to neurocognitive development at early infancy.
Collapse
Affiliation(s)
- Yeni Kim
- Department of Child and Adolescent Psychiatry, National Center for Mental Health, Seoul, Republic of Korea
| | - Eun-Hee Ha
- Department of Preventive Medicine, School of Medicine, EwhaWomans University College of Medicine, Seoul, Republic of Korea
| | - Hyesook Park
- Department of Preventive Medicine, School of Medicine, EwhaWomans University College of Medicine, Seoul, Republic of Korea
| | - Mina Ha
- Department of Preventive Medicine, College of Medicine, Dankook University College of Medicine, 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
| | - Yun-Chul Hong
- Institute of Environmental Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Eun Jung Lee
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Hyesook Kim
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Namsoo Chang
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Bung-Nyun Kim
- Department of Neuropsychiatry, School of Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
| |
Collapse
|
12
|
Geary DC. Evolution of Human Sex-Specific Cognitive Vulnerabilities. QUARTERLY REVIEW OF BIOLOGY 2017. [DOI: 10.1086/694934] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
13
|
Culbreth M, Zhang Z, Aschner M. Methylmercury augments Nrf2 activity by downregulation of the Src family kinase Fyn. Neurotoxicology 2017; 62:200-206. [PMID: 28736149 DOI: 10.1016/j.neuro.2017.07.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 12/26/2022]
Abstract
Methylmercury (MeHg) is a potent developmental neurotoxicant that induces an oxidative stress response in the brain. It has been demonstrated that MeHg exposure increases nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Nrf2 is a transcription factor that translocates to the nucleus in response to oxidative stress, and upregulates phase II detoxifying enzymes. Although, Nrf2 activity is augmented subsequent to MeHg exposure, it has yet to be established whether Nrf2 moves into the nucleus as a result. Furthermore, the potential effect MeHg might have on the non-receptor tyrosine kinase, Fyn, has not been addressed. Fyn phosphorylates Nrf2 in the nucleus, resulting in its inactivation, and consequent downregulation of the oxidative stress response. Here, we observe Nrf2 translocates to the nucleus subsequent to MeHg-induced oxidative stress. This response is concomitant with reduced Fyn expression and nuclear localization. Moreover, we detected an increase in phosphorylated Akt and glycogen synthase kinase 3 beta (GSK-3β) at activating and inhibitory sites, respectively. Akt phosphorylates and inhibits GSK-3β, which subsequently prevents Fyn phosphorylation to signal nuclear import. Our results demonstrate MeHg downregulates Fyn to maintain Nrf2 activity, and further illuminate a potential mechanism by which MeHg elicits neurotoxicity.
Collapse
Affiliation(s)
- Megan Culbreth
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
| | - Ziyan Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| |
Collapse
|
14
|
Jeong KS, Park H, Ha E, Shin J, Hong YC, Ha M, Park H, Kim BN, Lee B, Lee SJ, Lee KY, Kim JH, Kim Y. High Maternal Blood Mercury Level Is Associated with Low Verbal IQ in Children. J Korean Med Sci 2017; 32:1097-1104. [PMID: 28581265 PMCID: PMC5461312 DOI: 10.3346/jkms.2017.32.7.1097] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/16/2017] [Indexed: 11/20/2022] Open
Abstract
The objective of the present study was to investigate the relationship of IQ in children with maternal blood mercury concentration during late pregnancy. The present study is a component of the Mothers and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 553 children whose mothers underwent testing for blood mercury during late pregnancy. The children were given the Korean language version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R) at 60 months of age. Multivariate linear regression analysis, with adjustment for covariates, was used to assess the relationship between verbal, performance, and total IQ in children and blood mercury concentration of mothers during late pregnancy. The results of multivariate linear regression analysis indicated that a doubling of blood mercury was associated with the decrease in verbal and total IQ by 2.482 (95% confidence interval [CI], 0.749-4.214) and 2.402 (95% CI, 0.526-4.279), respectively, after adjustment. This inverse association remained after further adjustment for blood lead concentration. Fish intake is an effect modifier of child IQ. In conclusion, high maternal blood mercury level is associated with low verbal IQ in children.
Collapse
Affiliation(s)
- Kyoung Sook Jeong
- Department of Occupational and Environmental Medicine, Dongguk University College of Medicine, Dongguk University Ilsan Hospital, Goyang, Korea
| | - Hyewon Park
- Department of Child and Family Welfare, University of Ulsan, Ulsan, Korea
| | - Eunhee Ha
- Department of Occupational and Environmental Medicine and Medical Research Center, Ewha Womans University College of Medicine, Seoul, Korea
| | - Jiyoung Shin
- Department of Occupational and Environmental Medicine and Medical Research Center, Ewha Womans University College of Medicine, Seoul, Korea
| | - Yun Chul Hong
- Institute of Environmental Medicine, Medical Research Center, Seoul National University, Seoul, Korea
| | - Mina Ha
- Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Korea
| | - Hyesook Park
- Department of Preventive Medicine and Medical Research Center, Ewha Womans University College of Medicine, Seoul, Korea
| | - Bung Nyun Kim
- Department of Psychiatry, Seoul National University College of Medicine, Seoul, Korea
| | - Boeun Lee
- Monitoring and Analysis Division, Han River Basin Environmental Office, Hanam, Korea
| | - Soo Jeong Lee
- Department of Obstetrics and Gynecology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Kyung Yeon Lee
- Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Ja Hyeong Kim
- Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Yangho Kim
- Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
| |
Collapse
|
15
|
Llop S, Ballester F, Murcia M, Forns J, Tardon A, Andiarena A, Vioque J, Ibarluzea J, Fernández-Somoano A, Sunyer J, Julvez J, Rebagliato M, Lopez-Espinosa MJ. Prenatal exposure to mercury and neuropsychological development in young children: the role of fish consumption. Int J Epidemiol 2016; 46:827-838. [DOI: 10.1093/ije/dyw259] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2016] [Indexed: 01/10/2023] Open
|
16
|
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: 45] [Impact Index Per Article: 5.6] [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.
Collapse
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
| |
Collapse
|
17
|
Dysregulation of Glutamate Cycling Mediates Methylmercury-Induced Neurotoxicity. ADVANCES IN NEUROBIOLOGY 2016; 13:295-305. [PMID: 27885634 DOI: 10.1007/978-3-319-45096-4_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To examine the toxicological implications of glutamate, this chapter will focus specifically on its impact in the brain. More explicitly, it will illustrate the role glutamate plays in mediating methylmercury (MeHg)-induced neurotoxicity. In this chapter, one intends to highlight the processes that occur prior to glutamate-stimulated excitotoxicity and subsequent neurodegeneration. As such, it will emphasize three main routes by which MeHg alters glutamate homeostasis. It is essential to recognize that these effects are not mutually exclusive, and that they synergistically influence glutamate dysregulation. Furthermore, the consequences of MeHg exposure will be presented here as a direct pathway; however, it must be noted these effects occur simultaneously. First, glutamate uptake will be reviewed emphasizing the function of astrocytes. Next, the induction of oxidative stress by MeHg exposure will be discussed. This process has a two-fold effect on glutamate homeostasis by (1) inhibiting extracellular glutamate uptake and (2) altering transcription of genes vital to glutamate cycling. Finally, the impact glutamate dysregulation has on glutathione synthesis will be examined. Although this chapter centers on the link between glutamate and MeHg toxicity, it is imperative that the reader acknowledges the processes discussed here can be extended to any pro-oxidant.
Collapse
|
18
|
Curtis B, Liberato N, Rulien M, Morrisroe K, Kenney C, Yutuc V, Ferrier C, Marti CN, Mandell D, Burbacher TM, Sackett GP, Hewitson L. Examination of the safety of pediatric vaccine schedules in a non-human primate model: assessments of neurodevelopment, learning, and social behavior. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:579-589. [PMID: 25690930 PMCID: PMC4455585 DOI: 10.1289/ehp.1408257] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 02/12/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND In the 1990s, the mercury-based preservative thimerosal was used in most pediatric vaccines. Although there are currently only two thimerosal-containing vaccines (TCVs) recommended for pediatric use, parental perceptions that vaccines pose safety concerns are affecting vaccination rates, particularly in light of the much expanded and more complex schedule in place today. OBJECTIVES The objective of this study was to examine the safety of pediatric vaccine schedules in a non-human primate model. METHODS We administered vaccines to six groups of infant male rhesus macaques (n = 12-16/group) using a standardized thimerosal dose where appropriate. Study groups included the recommended 1990s Pediatric vaccine schedule, an accelerated 1990s Primate schedule with or without the measles-mumps-rubella (MMR) vaccine, the MMR vaccine only, and the expanded 2008 schedule. We administered saline injections to age-matched control animals (n = 16). Infant development was assessed from birth to 12 months of age by examining the acquisition of neonatal reflexes, the development of object concept permanence (OCP), computerized tests of discrimination learning, and infant social behavior. Data were analyzed using analysis of variance, multilevel modeling, and survival analyses, where appropriate. RESULTS We observed no group differences in the acquisition of OCP. During discrimination learning, animals receiving TCVs had improved performance on reversal testing, although some of these same animals showed poorer performance in subsequent learning-set testing. Analysis of social and nonsocial behaviors identified few instances of negative behaviors across the entire infancy period. Although some group differences in specific behaviors were reported at 2 months of age, by 12 months all infants, irrespective of vaccination status, had developed the typical repertoire of macaque behaviors. CONCLUSIONS This comprehensive 5-year case-control study, which closely examined the effects of pediatric vaccines on early primate development, provided no consistent evidence of neurodevelopmental deficits or aberrant behavior in vaccinated animals.
Collapse
Affiliation(s)
- Britni Curtis
- Infant Primate Research Laboratory, Washington National Primate Research Center, Seattle, Washington, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Nielsen SJ, Aoki Y, Kit BK, Ogden CL. More than half of US youth consume seafood and most have blood mercury concentrations below the EPA reference level, 2009-2012. J Nutr 2015; 145:322-7. [PMID: 25644354 PMCID: PMC7289318 DOI: 10.3945/jn.114.203786] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Consuming seafood has health benefits, but seafood can also contain methylmercury, a neurotoxicant. Exposure to methylmercury affects children at different stages of brain development, including during adolescence. OBJECTIVE The objective was to examine seafood consumption and blood mercury concentrations in US youth. METHODS In the 2009-2012 NHANES, a cross-sectional nationally representative sample of the US population, seafood consumption in the past 30 d and blood mercury concentrations on the day of examination were collected from 5656 youth aged 1-19 y. Log-linear regression was used to examine the association between frequency of specific seafood consumption and blood mercury concentration, adjusting for race/Hispanic origin, sex, and age. RESULTS In 2009-2012, 62.4% ± 1.4% (percent ± SE) of youth consumed any seafood in the preceding month; 38.4% ± 1.4% and 48.5% ± 1.5% reported consuming shellfish and fish, respectively. In 2009-2012, the geometric mean blood mercury concentration was 0.50 ± 0.02 μg/L among seafood consumers and 0.27 ± 0.01 μg/L among those who did not consume seafood. Less than 0.5% of youth had blood mercury concentrations ≥5.8 μg/L. In adjusted log-linear regression analysis, no significant associations were observed between frequency of breaded fish or catfish consumption and blood mercury concentrations, but frequency of consuming certain seafood types had significant positive association with blood mercury concentrations: high-mercury fish (swordfish and shark) [exponentiated β coefficient (expβ): 2.40; 95% CI: 1.23, 4.68]; salmon (expβ: 1.41; 95% CI: 1.26, 1.55); tuna (expβ: 1.38; 95% CI: 1.29, 1.45); crabs (expβ: 1.35; 95% CI: 1.17, 1.55); shrimp (expβ: 1.12; 95% CI: 1.05, 1.20), and all other seafood (expβ: 1.23; 95% CI: 1.17, 1.32). Age-stratified log-linear regression analyses produced similar results. CONCLUSION Few US youth have blood mercury concentrations ≥5.8 μg/L, although more than half of US youth consumed seafood in the past month.
Collapse
Affiliation(s)
- Samara Joy Nielsen
- Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD; and
| | - Yutaka Aoki
- Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD
| | - Brian K Kit
- Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD;,US Public Health Service, Rockville, MD
| | - Cynthia L Ogden
- Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD
| |
Collapse
|
20
|
Golding J, Emmett P, Iles-Caven Y, Steer C, Lingam R. A review of environmental contributions to childhood motor skills. J Child Neurol 2014; 29:1531-47. [PMID: 24170258 PMCID: PMC4004720 DOI: 10.1177/0883073813507483] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Although much of children's motor skills have a heredity component, at least half of the variance is likely to be influenced by the environment. It is important to ascertain features of the environment that are responsible so that toxins can be avoided, children at risk can be identified, and beneficial interventions initiated. This review outlines the results of published studies and recommends the areas where further research is required. We found much confusion with little comparability concerning the ages or measures used. Few studies had sufficient power and few allowed for confounders. We found that research to date implicates associations with prenatal drinking ≥4 drinks of alcohol per day; diabetes; taking antidepressant drugs; being deficient in iodine or iron; dietary fish; and postnatal depression. The child appearing to be most at risk was born of low birth weight (but not due to preterm delivery) or with neonatal problems.
Collapse
Affiliation(s)
- Jean Golding
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | | | | | | | | |
Collapse
|
21
|
Bisen-Hersh EB, Farina M, Barbosa F, Rocha JBT, Aschner M. Behavioral effects of developmental methylmercury drinking water exposure in rodents. J Trace Elem Med Biol 2014; 28:117-124. [PMID: 24210169 PMCID: PMC3979511 DOI: 10.1016/j.jtemb.2013.09.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/19/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
Abstract
Early methylmercury (MeHg) exposure can have long-lasting consequences likely arising from impaired developmental processes, the outcome of which has been exposed in several longitudinal studies of affected populations. Given the large number of newborns at an increased risk of learning disabilities associated with in utero MeHg exposure, it is important to study neurobehavioral alterations using ecologically valid and physiologically relevant models. This review highlights the benefits of using the MeHg drinking water exposure paradigm and outlines behavioral outcomes arising from this procedure in rodents. Combination treatments that exacerbate or ameliorate MeHg-induced effects, and possible molecular mechanisms underlying behavioral impairment are also discussed.
Collapse
Affiliation(s)
- Emily B Bisen-Hersh
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Marcelo Farina
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Fernando Barbosa
- Department of Clinical, Toxicological and Bromatological Analyses, Faculty of Pharmaceutical Sciences of Ribeirão Preto, São Paulo, Brazil
| | - Joao B T Rocha
- Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Michael Aschner
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, The Kennedy Center for Research on Human Development, and The Center for Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA
| |
Collapse
|
22
|
Valent F, Mariuz M, Bin M, Little D, Mazej D, Tognin V, Tratnik J, McAfee AJ, Mulhern MS, Parpinel M, Carrozzi M, Horvat M, Tamburlini G, Barbone F. Associations of prenatal mercury exposure from maternal fish consumption and polyunsaturated fatty acids with child neurodevelopment: a prospective cohort study in Italy. J Epidemiol 2013; 23:360-70. [PMID: 23933621 PMCID: PMC3775530 DOI: 10.2188/jea.je20120168] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 05/05/2013] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Mercury is a neurotoxin, and limited prenatal exposure to it can affect long-term child neurodevelopment. However, results of epidemiologic studies of such exposure have been inconsistent. We examined the association of prenatal mercury exposure from maternal fish consumption with child neurodevelopment in northern Italy. METHODS A population-based cohort of 606 children and their mothers was studied from pregnancy to age 18 months. Mercury levels were measured in maternal hair and blood during pregnancy and in umbilical cord blood and breast milk. Levels of polyunsaturated fatty acids (PUFAs) were measured in maternal serum. Maternal and child intakes of fish were assessed by using a food frequency questionnaire. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) was used to evaluate child neurodevelopment. Multivariate linear regression was used to examine the association of mercury exposure with BSID-III scores, after controlling for maternal fish intake, PUFAs during pregnancy, and several other confounders. RESULTS Mean weekly fish intake during pregnancy was less than 2 servings. Mercury concentrations in biological samples were low (mean, 1061 ng/g in hair) and moderately correlated with fish intake, particularly of carnivorous species. Maternal ω-3 PUFA concentrations were poorly correlated with fish intake. Maternal intelligence quotient (IQ) and child intake of fish were significantly associated with neurodevelopment scores. In multivariate models, the level of Hg exposure was not associated with neurodevelopmental performance at 18 months. CONCLUSIONS In this Italian population, neurodevelopment at 18 months was associated with child intake of fresh fish and maternal IQ rather than with mercury exposure. The expected beneficial effect of maternal fish intake (from maternal ω-3 PUFAs) was not found.
Collapse
Affiliation(s)
- Francesca Valent
- Institute of Hygiene and Clinical Epidemiology, University Hospital of Udine, Udine, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Llop S, Lopez-Espinosa MJ, Rebagliato M, Ballester F. Gender differences in the neurotoxicity of metals in children. Toxicology 2013; 311:3-12. [DOI: 10.1016/j.tox.2013.04.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 04/18/2013] [Accepted: 04/22/2013] [Indexed: 12/24/2022]
|
24
|
Ng S, Lin CC, Hwang YH, Hsieh WS, Liao HF, Chen PC. Mercury, APOE, and children's neurodevelopment. Neurotoxicology 2013; 37:85-92. [PMID: 23603214 DOI: 10.1016/j.neuro.2013.03.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/28/2013] [Accepted: 03/29/2013] [Indexed: 11/17/2022]
Abstract
The benefit of the nutritious elements in fish is insufficient for explaining the controversial finding regarding prenatal mercury (Hg) exposure and neurodevelopment; the varying frequency of susceptible genes among these populations may shed light on these observations. However, limited studies have been reported on the association between genetic susceptibility of prenatal Hg exposure and child development. Apolipoprotein E (APOE, protein; Apoe, gene) is a major protein transporter expressed in the brain. The Apoe epsilon 4 (ε4) allele is associated with poor neural repair function and is a risk factor associated with Alzheimer disease. We conducted a prospective cohort study in 2004 and 2005. In this study, 168 subjects were recruited at delivery and followed up at two years of age, and genetic polymorphisms of Apoe were included to assess genetic susceptibility and to determine the relationship between Hg concentrations in cord blood and neurodevelopment. The results showed that adverse effects on neurodevelopment were consistently associated with prenatal Hg exposure in all subtests of Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT) among ε4 carriers as assessed by both simple linear and multiple linear regression models. After controlling for confounding factors, statistical significance was found in the subtests of cognition tests (β=-8.47, 95% confidence interval (CI)=-16.10 to -0.84), social tests (β=-11.02, 95% CI=-20.85 to -1.19) and the whole test of CDIIT (β=-10.45, 95% CI=-17.36 to -3.54) in a multiple linear regression model. Additionally, the interaction effect between gene polymorphisms of Apoe and Hg levels was significant in the whole test CDIIT and subtests of cognition, language and fine motor tests. In conclusion, Apoe modifies the adverse effects of cord blood Hg on neurodevelopment at the age of two years.
Collapse
Affiliation(s)
- Sharon Ng
- Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan
| | | | | | | | | | | |
Collapse
|
25
|
Deroma L, Parpinel M, Tognin V, Channoufi L, Tratnik J, Horvat M, Valent F, Barbone F. Neuropsychological assessment at school-age and prenatal low-level exposure to mercury through fish consumption in an Italian birth cohort living near a contaminated site. Int J Hyg Environ Health 2013; 216:486-93. [PMID: 23523155 DOI: 10.1016/j.ijheh.2013.02.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 01/08/2013] [Accepted: 02/14/2013] [Indexed: 10/27/2022]
Abstract
The relative effects of prenatal and postnatal low-level mercury exposure and fish intake on child neurodevelopment are still controversial. Limited evidence is available from Mediterranean populations. In this prospective study, we measured the Verbal and Performance IQ in Italian children at school-age who were resident in an area declared as a National contaminated site because of mercury pollution, taking into account the possible beneficial effect of fish consumption and potential confounders. A mother-child cohort made up of 242 children was established at birth in Northeastern Italy in 2001. Their mothers were interviewed approximately 2 months after delivery to determine type, quantity, and origin of fish consumed during pregnancy and about a number of mother, child and family characteristics. Total mercury (THg) and methyl mercury (MeHg) were assessed in maternal hair and breast milk and in the child's hair. When children reached 7-9 years of age, 154 (63.6%) parents gave consent to participate in a follow-up evaluation. On that occasion, a child's hair sample was collected to determine the current concentration of THg, mothers were asked to complete a self-administered questionnaire, and children underwent neuropsychological testing. Verbal IQ, performance IQ and full scale IQ were measured by the Wechsler Intelligence Scale for Children (WISC III) administered by psychologists at school or local health centers. Demographic, socioeconomic and lifestyle information, medical information of the child's family and the child's dietary habits were collected using a questionnaire filled in by mothers. Multivariable linear regression models were used to evaluate the association between prenatal THg exposure through fish consumption of mothers in pregnancy and children's IQ after adjustment for possible confounders such as fish consumption of mothers in pregnancy, child's fish consumption at follow-up, child's birthweight, maternal cigarette smoking during pregnancy, house size and property place of residence during pregnancy and gender. THg in the child's hair at 7 years of age was fairly correlated with THg in maternal hair at delivery (rs=0.35; p<0.0001) and was strongly correlated with child's seafood consumption (rs=0.50, p<0.0001). No differences in maternal THg levels were found when comparing children with low or extremely low or high or extremely high scores vs others, considering separately full scale, verbal, and performance IQs. Children born from mothers with hair THg levels greater than or equal to 2000ng/g had full scale, verbal and performance IQs which were 4-5 points lower than children born from women with lower THg levels, but these differences were not statistically significant. Fresh fish intake of mothers in pregnancy was slightly positively associated with full scale and performance but not so with verbal IQs. Canned fish showed to be negatively associated with all the outcome variables. Unexpectedly, children born to mothers from one town showed IQ scores significantly lower than the other children; however, none of the many variables considered in these analyses could explain this result. The relatively low Hg levels found in the biological samples did not provide evidence of high and extensive Hg exposure in this population. Although THg levels in maternal and child's biological samples are correlated with fish consumption, the effects of THg and fish on neurological outcomes go in opposite directions. These results do not allow to develop recommendations regarding fish consumption in pregnancy but suggest that keeping THg hair levels<2000ng/g might be desirable.
Collapse
Affiliation(s)
- L Deroma
- Department of Medical and Biological Sciences, Udine University, Udine, Italy; SOC Centro di Coordinamento per le Malattie rare, Azienda Ospedaliero-Universitaria di Udine, Udine, Italy
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Valent F, Horvat M, Sofianou-Katsoulis A, Spiric Z, Mazej D, Little D, Prasouli A, Mariuz M, Tamburlini G, Nakou S, Barbone F. Neurodevelopmental effects of low-level prenatal mercury exposure from maternal fish consumption in a Mediterranean cohort: study rationale and design. J Epidemiol 2012; 23:146-52. [PMID: 23269124 PMCID: PMC3700240 DOI: 10.2188/jea.je20120030] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 09/09/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Mercury is a neurotoxic environmental pollutant. However, the literature on the neurodevelopmental effect of low-level prenatal mercury exposure from maternal fish intake is inconsistent. We assessed the association between prenatal mercury exposure and infant neurodevelopment in coastal areas of 4 Mediterranean countries. METHODS This was a prospective cohort study that planned to enroll approximately 1700 mother-infant pairs. Pregnant women and their newborn children were recruited in selected hospitals of the study areas. Biological samples, including maternal hair and cord blood, were collected from mothers and children, and the concentrations of mercury and other elements were measured. Exposures to lifestyle, environmental, and social factors were assessed through questionnaires. The main outcome was child neurodevelopment at 18 months, as measured by the Bayley Scales of Infant and Toddler Development, Third Edition. CONCLUSIONS This cohort has a number of strengths. First, mercury concentration was measured in several biological samples, which allows for a better understanding of mercury kinetics and is useful for sensitivity analyses. Therefore, we expect to be able to adjust for the potential confounding effects of lifestyle and social factors and for the effects of other elements that were measured in the biological samples. Finally, this is a multinational study and thus permits assessment of the relation between mercury and child neurodevelopment in different populations.
Collapse
Affiliation(s)
- Francesca Valent
- Institute of Hygiene and Epidemiology, Department of Medical and Biological Sciences (DSMB), University of Udine, Udine, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Mercury: What's In It For Kids? CLINICAL PEDIATRIC EMERGENCY MEDICINE 2012. [DOI: 10.1016/j.cpem.2012.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
28
|
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
| | | |
Collapse
|
29
|
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: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
30
|
Effects of environmental contaminant exposure on visual brain development: A prospective electrophysiological study in school-aged children. Neurotoxicology 2012; 33:1075-85. [DOI: 10.1016/j.neuro.2012.05.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 05/10/2012] [Accepted: 05/10/2012] [Indexed: 11/20/2022]
|
31
|
Murata K, Yoshida M, Sakamoto M, Iwai-Shimada M, Yaginuma-Sakurai K, Tatsuta N, Iwata T, Karita K, Nakai K. Recent evidence from epidemiological studies on methylmercury toxicity. Nihon Eiseigaku Zasshi 2011; 66:682-95. [PMID: 21996768 DOI: 10.1265/jjh.66.682] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
More than fifty years have passed since the outbreak of Minamata disease, and large-scale methylmercury poisoning due to industrial effluents or methylmercury-containing fungicide intoxication has scarcely happened in developed countries. On the other hand, widespread environmental mercury contamination has occurred in gold and mercury mining areas of developing countries. In this article, we provided an overview of recent studies addressing human health effects of methylmercury, which we searched using the PubMed of the US National Library of Medicine. The following suggestions were obtained for low-level methylmercury exposure: (1) In recent years, the proportion of human studies addressing methylmercury has tended to decrease. (2) Prenatal exposure to methylmercury through fish intake, even at low levels, adversely affects child development after adjusting for polychlorinated biphenyls and maternal fish intake during pregnancy, whereas maternal seafood intake has some benefits. (3) Long-term methylmercury exposure through consumption of fish such as bigeye tuna and swordfish may pose a potential risk of cardiac events involving sympathovagal imbalance. (4) In measuring methylmercury levels in preserved umbilical cord collected from inhabitants born in Minamata areas between 1945 and 1989, the elevated concentrations (≥1 mg/g) were observed mainly in inhabitants born between 1947 and 1968, and the peak coincided with the peak of acetaldehyde production in Minamata. (5) Since some developing countries appear to be in similar situations to Japan in the past, attention should be directed toward early recognition of a risky agent and precautions should be taken against it.
Collapse
Affiliation(s)
- Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Walker SP, Wachs TD, Grantham-McGregor S, Black MM, Nelson CA, Huffman SL, Baker-Henningham H, Chang SM, Hamadani JD, Lozoff B, Gardner JMM, Powell CA, Rahman A, Richter L. Inequality in early childhood: risk and protective factors for early child development. Lancet 2011; 378:1325-38. [PMID: 21944375 DOI: 10.1016/s0140-6736(11)60555-2] [Citation(s) in RCA: 798] [Impact Index Per Article: 61.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Inequality between and within populations has origins in adverse early experiences. Developmental neuroscience shows how early biological and psychosocial experiences affect brain development. We previously identified inadequate cognitive stimulation, stunting, iodine deficiency, and iron-deficiency anaemia as key risks that prevent millions of young children from attaining their developmental potential. Recent research emphasises the importance of these risks, strengthens the evidence for other risk factors including intrauterine growth restriction, malaria, lead exposure, HIV infection, maternal depression, institutionalisation, and exposure to societal violence, and identifies protective factors such as breastfeeding and maternal education. Evidence on risks resulting from prenatal maternal nutrition, maternal stress, and families affected with HIV is emerging. Interventions are urgently needed to reduce children's risk exposure and to promote development in affected children. Our goal is to provide information to help the setting of priorities for early child development programmes and policies to benefit the world's poorest children and reduce persistent inequalities.
Collapse
Affiliation(s)
- Susan P Walker
- Tropical Medicine Research Institute, The University of the West Indies, Kingston, Jamaica.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Boucher O, Burden MJ, Muckle G, Saint-Amour D, Ayotte P, Dewailly E, Nelson CA, Jacobson SW, Jacobson JL. Neurophysiologic and neurobehavioral evidence of beneficial effects of prenatal omega-3 fatty acid intake on memory function at school age. Am J Clin Nutr 2011; 93:1025-37. [PMID: 21389181 PMCID: PMC3076654 DOI: 10.3945/ajcn.110.000323] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The beneficial effects of prenatal and early postnatal intakes of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) on cognitive development during infancy are well recognized. However, few studies have examined the extent to which these benefits continue to be evident in childhood. OBJECTIVE The aim of this study was to examine the relation of n-3 PUFAs and seafood-contaminant intake with memory function in school-age children from a fish-eating community. DESIGN In a prospective, longitudinal study in Arctic Quebec, we assessed Inuit children (n = 154; mean age: 11.3 y) by using a continuous visual recognition task to measure 2 event-related potential components related to recognition memory processing: the FN400 and the late positive component (LPC). Children were also examined by using 2 well-established neurobehavioral assessments of memory: the Digit span forward from Wechsler Intelligence Scales for Children, 4th edition, and the California Verbal Learning Test-Children's Version. RESULTS Repeated-measures analyses of variance revealed that children with higher cord plasma concentrations of docosahexaenoic acid (DHA), which is an important n-3 PUFA, had a shorter FN400 latency and a larger LPC amplitude; and higher plasma DHA concentrations at the time of testing were associated with increased FN400 amplitude. Cord DHA-related effects were observed regardless of seafood-contaminant amounts. Multiple regression analyses also showed positive associations between cord DHA concentrations and performance on neurobehavioral assessments of memory. CONCLUSION To our knowledge, this study provides the first neurophysiologic and neurobehavioral evidence of long-term beneficial effects of n-3 PUFA intake in utero on memory function in school-age children.
Collapse
|
34
|
Magzamen S, Van Sickle D, Rose LD, Cronk C. Environmental pediatrics. Pediatr Ann 2011; 40:144-51. [PMID: 21417205 DOI: 10.3928/00904481-20110217-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Sheryl Magzamen
- Department of Population Health Sciences, University of Wisconsin, Madison, WI, USA
| | | | | | | |
Collapse
|
35
|
Prenatal exposure to methylmercury and PCBs affects distinct stages of information processing: an event-related potential study with Inuit children. Neurotoxicology 2010; 31:373-84. [PMID: 20403381 DOI: 10.1016/j.neuro.2010.04.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 03/27/2010] [Accepted: 04/12/2010] [Indexed: 11/23/2022]
Abstract
Methylmercury (MeHg) and polychlorinated biphenyls (PCBs) are seafood contaminants known for their adverse effects on neurodevelopment. This study examines the relation of developmental exposure to these contaminants to information processing assessed with event-related potentials (ERPs) in school-aged Inuit children from Nunavik (Arctic Québec). In a prospective longitudinal study on child development, exposure to contaminants was measured at birth and 11 years of age. An auditory oddball protocol was administered at 11 years to measure ERP components N1 and P3b. Multiple regression analyses were performed to examine the associations of levels of the contaminants to auditory oddball performance (mean reaction time, omission errors and false alarms) and ERP parameters (latency and amplitude) after control for potential confounding variables. A total of 118 children provided useable ERP data. Prenatal MeHg exposure was associated with slower reaction times and fewer false alarms during the oddball task. Analyses of the ERP parameters revealed that prenatal MeHg exposure was related to greater amplitude and delayed latency of the N1 wave in the target condition but not to the P3b component. MeHg effects on the N1 were stronger after control for seafood nutrients. Prenatal PCB exposure was not related to any endpoint for sample as a whole but was associated with a decrease in P3b amplitude in the subgroup of children who had been breast-fed for less than 3 months. Body burdens of MeHg and PCBs at 11 years were not related to any of the behavioural or ERP measures. These data suggest that prenatal MeHg exposure alters attentional mechanisms modulating early processing of sensory information. By contrast, prenatal PCB exposure appears to affect information processing at later stages, when the information is being consciously evaluated. These effects seem to be mitigated in children who are breast-fed for a more extended period.
Collapse
|
36
|
Hu G, Jin M, Lin X, Guo C, Zhang L, Sun Z. Mercury distribution in neonatal rat brain after intrauterine methylmercury exposure. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2010; 29:7-11. [PMID: 21787575 DOI: 10.1016/j.etap.2009.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 08/10/2009] [Accepted: 08/28/2009] [Indexed: 05/31/2023]
Abstract
Methylmercuric chloride (MMC) was orally administered to pregnant Wistar rats from gestational day 6 (G6) for 5 consecutive days. After delivery, the neonatal rats were decapitated and the cerebrum, cerebellum and hippocampus were excised on postnatal day (PND) 1, 7, 14, 21, 30 to determine total Hg contents and concentrations (six per stage). Both total Hg contents and concentrations in all the three regions increased as exposure dose increased and declined as postnatal time prolonged. Interestingly, differences of total Hg content between cerebrum and hippocampus at each time-point were significant (P<0.05). In the meantime, considering the Hg concentration, while no differences were observed before PND14 (P<0.05) among the three regions, Hg concentration in hippocampus was significantly higher than in cerebrum after that time period (P<0.05). We demonstrated that MeHg could pass through the placental and blood-brain barriers in a dose-dependent manner. Moreover, we found mercury redistribution occurred in offspring brain following the prolongation of postnatal time. The hippocampus was the major target of MeHg accumulation.
Collapse
Affiliation(s)
- Guiqin Hu
- School of Public Health Jilin University, Changchun, Jilin, People's Republic of China; Changchun The Bureau of Public Health Institute of Health Inspection, Changchun, Jilin, People's Republic of China
| | | | | | | | | | | |
Collapse
|
37
|
Defining a Lowest Observable Adverse Effect Hair Concentrations of Mercury for Neurodevelopmental Effects of Prenatal Methylmercury Exposure Through Maternal Fish Consumption: A Systematic Review. Ther Drug Monit 2009; 31:670-82. [DOI: 10.1097/ftd.0b013e3181bb0ea1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
38
|
Glover CN, Zheng D, Jayashankar S, Sales GD, Hogstrand C, Lundebye AK. Methylmercury Speciation Influences Brain Gene Expression and Behavior in Gestationally-Exposed Mice Pups. Toxicol Sci 2009; 110:389-400. [DOI: 10.1093/toxsci/kfp105] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
39
|
Neurobehavioural functions in adult progeny of rat mothers exposed to methylmercury or 2,2', 4,4', 5,5'-hexachlorobiphenyl (PCB 153) alone or their combination during gestation and lactation. Int J Occup Med Environ Health 2009; 22:277-91. [DOI: 10.2478/v10001-009-0020-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
40
|
Yin Z, Jiang H, Syversen T, Rocha JBT, Farina M, Aschner M. The methylmercury-L-cysteine conjugate is a substrate for the L-type large neutral amino acid transporter. J Neurochem 2008; 107:1083-90. [PMID: 18793329 DOI: 10.1111/j.1471-4159.2008.05683.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Methylmercury (MeHg) is a potent neurotoxin. The mechanism(s) that governs MeHg transport across the blood-brain barrier and other biological membranes remains unclear. This study addressed the role of the L-type large neutral amino acid transporter, LAT1, in MeHg transport. Studies were carried out in CHO-k1 cells. Over-expression of LAT1 in these cells was associated with enhanced uptake of [(14)C]-MeHg when treated with L-cysteine, but not with the D-cysteine conjugate. In the presence of excess L-methionine, a substrate for LAT1, L-cysteine-conjugated [(14)C]-MeHg uptake was significantly attenuated. Treatment of LAT-1 over-expressing CHO-k1 cells with L-cysteine-conjugated MeHg was also associated with increased leakage of lactate dehydrogenase into the media as well as reduced cell viability measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. In contrast, knock-down of LAT1 decreased the uptake of l-cysteine-conjugated MeHg and attenuated the effects of MeHg on lactate dehydrogenase leakage and CHO-k1 cell viability. These results indicate that the MeHg-L-cysteine conjugate is a substrate for the neutral amino acid transporter, LAT1, which actively transports MeHg across membranes.
Collapse
Affiliation(s)
- Zhaobao Yin
- Department of Pediatrics, Kennedy Center for Research on human Development, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
| | | | | | | | | | | |
Collapse
|