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Association of prenatal exposure to dioxin-like compounds, polychlorinated biphenyl, and methylmercury with event-related brain potentials in school-aged children: the Hokkaido study. Neurotoxicology 2022; 91:11-21. [DOI: 10.1016/j.neuro.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 03/18/2022] [Accepted: 04/24/2022] [Indexed: 11/18/2022]
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Ochiai M, Nguyen HT, Kurihara N, Hirano M, Tajima Y, Yamada TK, Iwata H. Directly Reprogrammed Neurons as a Tool to Assess Neurotoxicity of the Contaminant 4-Hydroxy-2',3,5,5'-tetrachlorobiphenyl (4'OH-CB72) in Melon-Headed Whales. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8159-8168. [PMID: 34061511 DOI: 10.1021/acs.est.1c01074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Whales accumulate high levels of environmental pollutants. Exposure to polychlorinated biphenyls (PCBs) and their metabolites (OH-PCBs) could be linked to abnormal behavior, which may lead to mass stranding of marine mammals. Whales may thus suffer from adverse effects such as neuronal dysfunction, yet testing the neurotoxicity of these compounds has never been feasible for these species. This study established neurons chemically reprogrammed from fibroblasts of mass stranded melon-headed whales (Peponocephala electra) and used them for in vitro neurotoxicity assays. Exposure to 4-hydroxy-2',3,5,5'-tetrachlorobiphenyl (4'OH-CB72), a metabolite of PCBs, caused apoptosis in the reprogrammed neurons. Transcriptome analysis of 4'OH-CB72-treated whale neurons showed altered expressions of genes associated with oxidative phosphorylation, chromatin degradation, axonal transport, and neurodegenerative diseases. These results suggest that 4'OH-CB72 exposure may induce neurodegeneration through disrupted apoptotic processes. A comparison of the results with human reprogrammed neurons revealed the specific effects on the whale neurons. Our noninvasive approach using fibroblast-derived neurons is useful for hazard and risk assessments of neurotoxicity in whales.
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Affiliation(s)
- Mari Ochiai
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama City, Ehime 790-8577, Japan
| | - Hoa Thanh Nguyen
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama City, Ehime 790-8577, Japan
| | - Nozomi Kurihara
- Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1, Yoshida, Yamaguchi City, Yamaguchi 753-8515, Japan
| | - Masashi Hirano
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama City, Ehime 790-8577, Japan
| | - Yuko Tajima
- Division of Vertebrates, Department of Zoology, National Museum of Nature and Science, 4-1-1, Amakubo, Tsukuba, Ibaraki 305-0005, Japan
| | - Tadasu K Yamada
- Division of Vertebrates, Department of Zoology, National Museum of Nature and Science, 4-1-1, Amakubo, Tsukuba, Ibaraki 305-0005, Japan
| | - Hisato Iwata
- Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama City, Ehime 790-8577, Japan
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Simhadri JJ, Loffredo CA, Trnovec T, Murinova LP, Nunlee-Bland G, Koppe JG, Schoeters G, Jana SS, Ghosh S. Biomarkers of metabolic disorders and neurobehavioral diseases in a PCB- exposed population: What we learned and the implications for future research. ENVIRONMENTAL RESEARCH 2020; 191:110211. [PMID: 32937175 PMCID: PMC7658018 DOI: 10.1016/j.envres.2020.110211] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/08/2020] [Indexed: 05/15/2023]
Abstract
Polychlorinated biphenyls (PCBs) are one of the original twelve classes of toxic chemicals covered by the Stockholm Convention on Persistent Organic Pollutants (POP), an international environmental treaty signed in 2001. PCBs are present in the environment as mixtures of multiple isomers at different degree of chlorination. These compounds are manmade and possess useful industrial properties including extreme longevity under harsh conditions, heat absorbance, and the ability to form an oily liquid at room temperature that is useful for electrical utilities and in other industrial applications. They have been widely used for a wide range of industrial purposes over the decades. Despite a ban in production in 1979 in the US and many other countries, they remain persistent and ubiquitous in environment as contaminants due to their improper disposal. Humans, independent of where they live, are therefore exposed to PCBs, which are routinely found in random surveys of human and animal tissues. The prolonged exposures to PCBs have been associated with the development of different diseases and disorders, and they are classified as endocrine disruptors. Due to its ability to interact with thyroid hormone, metabolism and function, they are thought to be implicated in the global rise of obesity diabetes, and their potential toxicity for neurodevelopment and disorders, an example of gene by environmental interaction (GxE). The current review is primarily intended to summarize the evidence for the association of PCB exposures with increased risks for metabolic dysfunctions and neurobehavioral disorders. In particular, we present evidence of gene expression alterations in PCB-exposed populations to construct the underlying pathways that may lead to those diseases and disorders in course of life. We conclude the review with future perspectives on biomarker-based research to identify susceptible individuals and populations.
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Affiliation(s)
- Jyothirmai J Simhadri
- Department of Pediatrics and Child Health, College of Medicine, Howard University, Washington DC, USA
| | - Christopher A Loffredo
- Departments of Oncology and of Biostatistics, Georgetown University, Washington, DC, USA
| | - Tomas Trnovec
- Department of Pediatrics, EKZ-AMC, University of Amsterdam, Netherlands
| | | | - Gail Nunlee-Bland
- Department of Pediatrics and Child Health, College of Medicine, Howard University, Washington DC, USA
| | - Janna G Koppe
- Department of Pediatrics, EKZ-AMC, University of Amsterdam, Netherlands
| | - Greet Schoeters
- Dept. Biomedical Sciences, University of Antwerp, Antwerp, Belgium & Flemish Institute for Technological Research (VITO), Mol, Belgium
| | | | - Somiranjan Ghosh
- Department of Pediatrics and Child Health, College of Medicine, Howard University, Washington DC, USA; Department of Biology, Howard University, Washington, DC, USA.
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Goodman M, Li J, Flanders WD, Mahood D, Anthony LG, Zhang Q, LaKind JS. Epidemiology of PCBs and neurodevelopment: Systematic assessment of multiplicity and completeness of reporting. GLOBAL EPIDEMIOLOGY 2020. [DOI: 10.1016/j.gloepi.2020.100040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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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] [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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Nilsen FM, Ruiz JD, Tulve NS. A Meta-Analysis of Stressors from the Total Environment Associated with Children's General Cognitive Ability. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17155451. [PMID: 32751096 PMCID: PMC7432904 DOI: 10.3390/ijerph17155451] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/31/2022]
Abstract
General cognitive ability, often referred to as ‘general intelligence’, comprises a variety of correlated abilities. Childhood general cognitive ability is a well-studied area of research and can be used to predict social outcomes and perceived success. Early life stage (e.g., prenatal, postnatal, toddler) exposures to stressors (i.e., chemical and non-chemical stressors from the total (built, natural, social) environment) can impact the development of childhood cognitive ability. Building from our systematic scoping review (Ruiz et al., 2016), we conducted a meta-analysis to evaluate more than 100 stressors related to cognitive development. Our meta-analysis identified 23 stressors with a significant increase in their likelihood to influence childhood cognitive ability by 10% or more, and 80 stressors were observed to have a statistically significant effect on cognitive ability. Stressors most impactful to cognition during the prenatal period were related to maternal health and the mother’s ability to access information relevant to a healthy pregnancy (e.g., diet, lifestyle). Stressors most impactful to cognition during the early childhood period were dietary nutrients (infancy), quality of social interaction (toddler), and exposure to toxic substances (throughout early childhood). In conducting this analysis, we examined the relative impact of real-world exposures on cognitive development to attempt to understand the inter-relationships between exposures to both chemical and non-chemical stressors and early developmental life stages. Our findings suggest that the stressors observed to be the most influential to childhood cognitive ability are not permanent and can be broadly categorized as activities/behaviors which can be modified to improve childhood cognition. This meta-analysis supports the idea that there are complex relationships between a child’s total environment and early cognitive development.
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Affiliation(s)
- Frances M. Nilsen
- Office of Research and Development, U.S. Environmental Protection Agency Research Triangle Park, Durham, NC 27709, USA; (J.D.C.R.); (N.S.T.)
- Correspondence: ; Tel.: +1-919-541-2574
| | - Jazmin D.C. Ruiz
- Office of Research and Development, U.S. Environmental Protection Agency Research Triangle Park, Durham, NC 27709, USA; (J.D.C.R.); (N.S.T.)
- Honeywell International, Buffalo, NY 14210, USA
| | - Nicolle S. Tulve
- Office of Research and Development, U.S. Environmental Protection Agency Research Triangle Park, Durham, NC 27709, USA; (J.D.C.R.); (N.S.T.)
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Fini JB, Demeneix B. [Thyroid disruptors and their consequences on brain development and behavior]. Biol Aujourdhui 2019; 213:17-26. [PMID: 31274099 DOI: 10.1051/jbio/2019009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Indexed: 06/09/2023]
Abstract
An increase in the prevalence of many diseases affecting the nervous system in both children and adults has been reported. Some of these diseases are related to endocrine dysfunction, notably of the thyroid axis. Examples in children are attention deficit/hyperactivity disorders and Autism Spectrum Disorders, diagnosed but most often affecting the whole life, and multiple sclerosis or Alzheimer's disease in adults. It is becoming increasingly clear that embryonic exposure to thyroid hormone disruptors can lead to short- and long-term consequences, that often escape conventional neonatal diagnosis. Endocrine disruptors comprise a wide range of molecules, plasticizers, some pesticides, surfactants, flame-retardants, etc., many of which can interfere with thyroid hormone synthesis or their actions. We here report briefly the history of endocrine disruptors, their properties and the consequences on neuronal development of embryonic exposure to some of them.
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Affiliation(s)
- Jean-Baptiste Fini
- Muséum National d'Histoire Naturelle, CNRS UMR 7221, Laboratoire Physiologie moléculaire de l'adaptation, 7 rue Cuvier, 75005 Paris, France
| | - Barbara Demeneix
- Muséum National d'Histoire Naturelle, CNRS UMR 7221, Laboratoire Physiologie moléculaire de l'adaptation, 7 rue Cuvier, 75005 Paris, France
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Kyriklaki A, Vafeiadi M, Kampouri M, Koutra K, Roumeliotaki T, Chalkiadaki G, Anousaki D, Rantakokko P, Kiviranta H, Fthenou E, Bitsios P, Kyrtopoulos SA, Kogevinas M, Chatzi L. Prenatal exposure to persistent organic pollutants in association with offspring neuropsychological development at 4years of age: The Rhea mother-child cohort, Crete, Greece. ENVIRONMENT INTERNATIONAL 2016; 97:204-211. [PMID: 27666324 DOI: 10.1016/j.envint.2016.09.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Persistent Organic Pollutants (POPs) are highly-resistant compounds to environmental degradation and due to fat solubility they bioaccumulate through the food chain. As they cross the placenta, in utero exposure to POPs could disrupt child neurodevelopment as they are considered to be neurotoxic. AIMS We examined whether in utero exposure to levels of different POPs is associated with offspring cognitive and behavioral outcomes at 4years of age in a mother-child cohort in Crete, Greece (Rhea study). METHODS We included 689 mother-child pairs. Concentrations of several polychlorinated biphenyls (PCBs) and other organochlorine compounds (dichlorodiphenyl dichloroethene [DDE], hexachlorobenzene [HCB]) were determined in maternal serum collected in the first trimester of pregnancy by triple quadrupole mass spectrometry. Neurodevelopment at 4years was assessed by means of the McCarthy Scales of Children's Abilities. Behavioral difficulties were assessed by Strengths and Difficulties Questionnaire and Attention Deficit Hyperactivity Disorder Test. Linear regression analyses were used to estimate the associations between the exposures and outcomes of interest after adjustment for potential confounders. RESULTS Children with "high" HCB concentrations (≥90th percentile) in maternal serum, demonstrated decreased scores in perceptual performance (adjusted β=-6.07; 95% CI: -10.17, -1.97), general cognitive (adjusted β=-4.97; 95% CI: -8.99, -0.96), executive function (adjusted β=-6.24; 95% CI: -10.36, -2.11) and working memory (adjusted β=-4.71; 95% CI: -9.05, -0.36) scales at 4years of age. High exposure to PCBs (≥90th percentile) during pregnancy was associated with a 4.62 points reduction in working memory score at 4years of age (95% CI: -9.10, -0.14). Prenatal exposure to DDE, HCB and PCBs was not associated with child behavioral difficulties. CONCLUSIONS The findings suggest that prenatal exposure to HCB and PCBs may contribute to reduced cognitive development at preschool age. Our results raise the possibility that exposure to HCB may play a more important role in child cognition than previously considered.
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Affiliation(s)
- Andriani Kyriklaki
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Marina Vafeiadi
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece.
| | - Mariza Kampouri
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Katerina Koutra
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Theano Roumeliotaki
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Georgia Chalkiadaki
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Despoina Anousaki
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Panu Rantakokko
- Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland
| | - Hannu Kiviranta
- Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland
| | - Eleni Fthenou
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Panos Bitsios
- Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Soterios A Kyrtopoulos
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, Athens, Greece
| | - Manolis Kogevinas
- Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Hospital del Mar Research Institute (IMIM), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
| | - Leda Chatzi
- Department of Social Medicine, Faculty of Medicine, University of Crete, Heraklion, Greece
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Ruiz JDC, Quackenboss JJ, Tulve NS. Contributions of a Child's Built, Natural, and Social Environments to Their General Cognitive Ability: A Systematic Scoping Review. PLoS One 2016; 11:e0147741. [PMID: 26840411 PMCID: PMC4739499 DOI: 10.1371/journal.pone.0147741] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/09/2015] [Indexed: 12/24/2022] Open
Abstract
The etiology of a child’s cognitive ability is complex, with research suggesting that it is not attributed to a single determinant or even a defined period of exposure. Rather, cognitive development is the product of cumulative interactions with the environment, both negative and positive, over the life course. The aim of this systematic scoping review was to collate evidence associated with children’s cognitive health, including inherent factors as well as chemical and non-chemical stressors from the built, natural, and social environments. Three databases were used to identify recent epidemiological studies (2003–2013) that examined exposure factors associated with general cognitive ability in children. Over 100 factors were evaluated from 258 eligible studies. We found that recent literature mainly assessed the hypothesized negative effects of either inherent factors or chemical exposures present in the physical environment. Prenatal growth, sleep health, lead and water pollutants showed consistent negative effects. Of the few studies that examined social stressors, results consistently showed cognitive development to be influenced by both positive and negative social interactions at home, in school or the community. Among behavioral factors related to diet and lifestyle choices of the mother, breastfeeding was the most studied, showing consistent positive associations with cognitive ability. There were mostly inconsistent results for both chemical and non-chemical stressors. The majority of studies utilized traditional exposure assessments, evaluating chemical and non-chemical stressors separately. Collective evidence from a limited number of studies revealed that cumulative exposure assessment that incorporates multiple chemical and non-chemical stressors over the life course may unravel the variability in effect on cognitive development and help explain the inconsistencies across studies. Future research examining the interactions of multiple stressors within a child’s total environment, depicting a more real-world exposure, will aid in understanding the cumulative effects associated with a child’s ability to learn.
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Affiliation(s)
- Jazmin Del Carmen Ruiz
- Oak Ridge Institute for Science and Education, Research Participation Program, Oak Ridge, TN, United States of America
- Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States of America
- * E-mail: ;
| | - James J. Quackenboss
- Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Las Vegas, NV, United States of America
| | - Nicolle S. Tulve
- Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, Durham, NC, United States of America
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Tatsuta N, Nakai K, Murata K, Suzuki K, Iwai-Shimada M, Kurokawa N, Hosokawa T, Satoh H. Impacts of prenatal exposures to polychlorinated biphenyls, methylmercury, and lead on intellectual ability of 42-month-old children in Japan. ENVIRONMENTAL RESEARCH 2014; 133:321-6. [PMID: 24998460 DOI: 10.1016/j.envres.2014.05.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 05/08/2014] [Accepted: 05/27/2014] [Indexed: 05/23/2023]
Abstract
BACKGROUND The age-specific impacts of perinatal exposures to polychlorinated biphenyls (PCB), methylmercury (MeHg), and lead on child neurodevelopment remain controversial. Since we have already reported the prenatal effects of these chemicals on neurodevelopment in 3-day-old and 30-month-old children of a birth cohort, the following effects were analyzed in the 42-month-old children in the same cohort. METHODS The Kaufman Assessment Battery for Children (K-ABC), comprised of four scales, was used to assess their intelligence and achievement. The relationships between the chemicals and K-ABC scores were analyzed using multivariate analyses. RESULTS The median values of chemicals in cord blood of 387 children were 46.5 (5th and 95th percentiles, 16.7-115.7)ng/g-lipid for total PCB, 10.1 (4.3-22.2)ng/g for total mercury (THg), and 1.0 (0.5-1.8) μg/dL for lead. Of the highly chlorinated PCB homologs, 9 CBs was negatively correlated with the sequential and mental processing score of the K-ABC (p<0.05). There were no significant correlations between any K-ABC score and either THg or lead. The negative effect of 9 CBs remained even after adjusting for THg, lead, and other confounders. The K-ABC scores were significantly lower in the boys than in the girls, and the standardized β of 9 CBs for the sequential and mental processing scores in multiple regression analysis was statistically significant in boys. CONCLUSIONS These findings suggest that intellectual ability in the developmental stage may be impaired by prenatal exposures to highly chlorinated PCB homologs, especially in Japanese boys.
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Affiliation(s)
- Nozomi Tatsuta
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Miyagi, Sendai 980-8575, Japan
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Miyagi, Sendai 980-8575, Japan.
| | - Katsuyuki Murata
- Environmental Health Sciences, Akita University Graduate School of Medicine, Akita 010-8543, Japan
| | - Keita Suzuki
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Miyuki Iwai-Shimada
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Naoyuki Kurokawa
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Toru Hosokawa
- Human Development and Disabilities, Tohoku University Graduate School of Education, Sendai 980-8576, Japan
| | - Hiroshi Satoh
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
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Préau L, Fini JB, Morvan-Dubois G, Demeneix B. Thyroid hormone signaling during early neurogenesis and its significance as a vulnerable window for endocrine disruption. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:112-21. [PMID: 24980696 DOI: 10.1016/j.bbagrm.2014.06.015] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/14/2014] [Accepted: 06/20/2014] [Indexed: 12/11/2022]
Abstract
The essential roles of thyroid hormone (TH) in perinatal brain development have been known for decades. More recently, many of the molecular mechanisms underlying the multiple effects of TH on proliferation, differentiation, migration, synaptogenesis and myelination in the developing nervous system have been elucidated. At the same time data from both epidemiological studies and animal models have revealed that the influence of thyroid signaling on development of the nervous system, extends to all periods of life, from early embryogenesis to neurogenesis in the adult brain. This review focuses on recent insights into the actions of TH during early neurogenesis. A key concept is that, in contrast to the previous ideas that only the unliganded receptor was implicated in these early phases, a critical role of the ligand, T3, is increasingly recognized. These findings are considered in the light of increasing knowledge of cell specific control of T3 availability as a function of deiodinase activity and transporter expression. These requirements for TH in the early stages of neurogenesis take on new relevance given the increasing epidemiological data on adverse effects of TH lack in early pregnancy on children's neurodevelopmental outcome. These ideas lead logically into a discussion on how the actions of TH during the first phases of neurogenesis can be potentially disrupted by gestational iodine lack and/or chemical pollution. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
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Affiliation(s)
- Laetitia Préau
- UMR CNRS 7221, Evolution des Régulations Endocriniennes, Département Régulations, Développement et Diversité Moléculaire, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - Jean Baptiste Fini
- UMR CNRS 7221, Evolution des Régulations Endocriniennes, Département Régulations, Développement et Diversité Moléculaire, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - Ghislaine Morvan-Dubois
- UMR CNRS 7221, Evolution des Régulations Endocriniennes, Département Régulations, Développement et Diversité Moléculaire, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - Barbara Demeneix
- UMR CNRS 7221, Evolution des Régulations Endocriniennes, Département Régulations, Développement et Diversité Moléculaire, Muséum National d'Histoire Naturelle, 75231 Paris, France.
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Choi AL, Mogensen UB, Bjerve KS, Debes F, Weihe P, Grandjean P, Budtz-Jørgensen E. Negative confounding by essential fatty acids in methylmercury neurotoxicity associations. Neurotoxicol Teratol 2014; 42:85-92. [PMID: 24561639 DOI: 10.1016/j.ntt.2014.02.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 01/21/2023]
Abstract
BACKGROUND Methylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result in underestimation of both mercury toxicity and nutrient benefits unless mutual adjustment is included in the analysis. METHODS We examined these associations in 176 Faroese children, in whom prenatal methylmercury exposure was assessed from mercury concentrations in cord blood and maternal hair. The relative concentrations of fatty acids were determined in cord serum phospholipids. Neuropsychological performance in verbal, motor, attention, spatial, and memory functions was assessed at 7 years of age. Multiple regression and structural equation models (SEMs) were carried out to determine the confounder-adjusted associations with methylmercury exposure. RESULTS A short delay recall (in percent change) in the California Verbal Learning Test (CVLT) was associated with a doubling of cord blood methylmercury (-18.9, 95% confidence interval [CI]=-36.3, -1.51). The association became stronger after the inclusion of fatty acid concentrations in the analysis (-22.0, 95% confidence interval [CI]=-39.4, -4.62). In structural equation models, poorer memory function (corresponding to a lower score in the learning trials and short delay recall in CVLT) was associated with a doubling of prenatal exposure to methylmercury after the inclusion of fatty acid concentrations in the analysis (-1.94, 95% CI=-3.39, -0.49). CONCLUSIONS Associations between prenatal exposure to methylmercury and neurobehavioral deficits in memory function at school age were strengthened after fatty acid adjustment, thus suggesting that n-3 fatty acids need to be included in analysis of similar studies to avoid underestimation of the associations with methylmercury exposure.
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Affiliation(s)
- Anna L Choi
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
| | - Ulla B Mogensen
- Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark
| | - Kristian S Bjerve
- Department of Medical Biochemistry, St. Olavs Hospital, Trondheim University Hospital, N-7021 Trondheim, Norway; Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Frodi Debes
- Faroese Hospital System, Torshavn, Faroe Islands
| | - Pal Weihe
- Faroese Hospital System, Torshavn, Faroe Islands
| | - Philippe Grandjean
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA; Institute of Public Health, University of Southern Denmark, Odense, Denmark
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Newman J, Behforooz B, Khuzwayo AG, Gallo MV, Schell LM. PCBs and ADHD in Mohawk adolescents. Neurotoxicol Teratol 2014; 42:25-34. [PMID: 24462617 DOI: 10.1016/j.ntt.2014.01.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 01/10/2014] [Accepted: 01/13/2014] [Indexed: 11/24/2022]
Abstract
The present study examines the relationship between the levels of persistent polychlorinated biphenyls (PCBs) in adolescents' blood serum and concurrent measures of their ADHD-like behavior derived from ratings provided by parents and teachers. Two measures with demonstrated diagnostic validity, the Conners and ADDES scales, are used. The study was conducted in partnership with the Mohawk Nation at Akwesasne where the St. Lawrence River and surrounding waterways have been contaminated with PCBs that have entered the food chain. This study examines a subset of the data derived from the Mohawk Adolescent Well-Being Study (MAWBS), which was designed to investigate psychosocial and health related outcomes of 271 adolescents aged 10 years to 17 years and whose mothers were likely to have consumed PCB-contaminated fish and wild game before and during their pregnancy. No evidence of negative effects of adolescent blood PCB levels on ADHD-like behavior was found, and indeed occasional findings were in the unexpected direction. The possibility of negative confounding by SES and breastfeeding history was examined but dismissed.
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Affiliation(s)
- Joan Newman
- Educational Psychology and Methodology, University at Albany, 1400 Washington Ave., Albany, NY 12222, USA.
| | - Bita Behforooz
- Educational Psychology and Methodology, University at Albany, 1400 Washington Ave., Albany, NY 12222, USA
| | - Amy G Khuzwayo
- School Psychology, University at Albany, 1400 Washington Ave., Albany, NY 12222, USA
| | - Mia V Gallo
- Department of Anthropology, 1400 Washington Ave., Albany, NY 12222, USA; Center for the Elimination of Minority Health Disparities, 1400 Washington Ave., NY 12222, USA
| | - Lawrence M Schell
- Department of Anthropology, 1400 Washington Ave., Albany, NY 12222, USA; Center for the Elimination of Minority Health Disparities, 1400 Washington Ave., NY 12222, USA; Department of Epidemiology and Biostatistics, School of Public Health, One University Place, Rensselaer, NY, USA
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Engel SM, Wolff MS. Causal inference considerations for endocrine disruptor research in children's health. Annu Rev Public Health 2013; 34:139-58. [PMID: 23514318 DOI: 10.1146/annurev-publhealth-031811-124556] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Substantial population exposure to endocrine disrupting chemicals, combined with available biomarkers and public concern, has resulted in an explosion of human health effects research. At the same time, remarkable shifts in the regulations governing the composition of some consumer products that contain endocrine disruptors (EDs) has occurred. However, important questions remain as to the weight of evidence linking EDs to human health end points. In this review, we critically examine the literature linking ED exposures to child neurodevelopment, focusing in particular on two model exposures to demonstrate issues related to bioaccumulative [e.g., polychlorinated biphenyls (PCBs)] and rapidly metabolized (e.g., phthalates) compounds, respectively. Issues of study design, confounding, and exposure measurement are considered. Given widespread exposure to these compounds, the potential public health consequences of even small effects on human health are substantial. Therefore, advancing our understanding of any impact calls for careful attention to the principles of causal inference.
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Affiliation(s)
- Stephanie M Engel
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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El Majidi N, Bouchard M, Carrier G. Systematic analysis of the relationship between standardized prenatal exposure to polychlorinated biphenyls and mental and motor development during follow-up of nine children cohorts. Regul Toxicol Pharmacol 2013; 66:130-46. [PMID: 23524270 DOI: 10.1016/j.yrtph.2013.03.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 03/05/2013] [Accepted: 03/10/2013] [Indexed: 11/19/2022]
Abstract
Impact of prenatal exposure to polychlorinated biphenyls (PCBs) on mental and motor development has been investigated in various children cohorts, but findings show temporal inconsistencies. Because a direct comparison of results obtained from different cohorts remains difficult, temporal relationship between biological PCB concentrations and long-term developmental effects is still not clearly established. The objective of this research was to use a procedure previously developed to standardize PCB biological concentration data across cohorts in order to perform a systematic analysis of temporal associations between prenatal PCB exposure and mental and motor development from neonatal period (or a young age) until school age. Prenatal exposure data from nine cohorts were standardized in terms of total PCBs per kg of lipids in maternal plasma. Systematic analysis of the "standardized biological concentration-development" relationship during follow-up of each cohort was then conducted through the application of Hill criteria. This led to retain six of the studied cohorts in the final analysis. A biological level of prenatal PCB exposure below which risk of mental or motor development should be negligible was established in the order of 1000μg/kg of lipids in maternal plasma.
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Affiliation(s)
- Naïma El Majidi
- Département de santé environnementale et santé au travail, Chaire d'analyse et de gestion des risques toxicologiques and Institut de recherche en santé publique de l'Université de Montréal (IRSPUM), Faculty of Medicine, Université de Montréal, P.O. Box 6128, Main Station, Montreal, Quebec, Canada H3C 3J7
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Grandjean P, Weihe P, Nielsen F, Heinzow B, Debes F, Budtz-Jørgensen E. Neurobehavioral deficits at age 7 years associated with prenatal exposure to toxicants from maternal seafood diet. Neurotoxicol Teratol 2012; 34:466-72. [PMID: 22705177 PMCID: PMC3407364 DOI: 10.1016/j.ntt.2012.06.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 06/01/2012] [Accepted: 06/01/2012] [Indexed: 10/28/2022]
Abstract
To determine the possible neurotoxic impact of prenatal exposure to polychlorinated biphenyls (PCBs), we analyzed banked cord blood from a Faroese birth cohort for PCBs. The subjects were born in 1986-1987, and 917 cohort members had completed a series of neuropsychological tests at age 7 years. Major PCB congeners (118, 138, 153, and 180), the calculated total PCB concentration, and the PCB exposure estimated in a structural equation model showed weak associations with test deficits, with statistically significant negative associations only with the Boston Naming test. Likewise, neither hexachlorobenzene nor p,p'-dichlorodiphenyldichloroethylene showed clear links to neurobehavioral deficits. Thus, these associations were much weaker than those associated with the cord-blood mercury concentration, and adjustment for mercury substantially attenuated the regression coefficients for PCB exposure. When the outcomes were joined into motor and verbally mediated functions in a structural equation model, the PCB effects remained weak and virtually disappeared after adjustment for methylmercury exposure, while mercury remained statistically significant. Thus, in the presence of elevated methylmercury exposure, PCB neurotoxicity may be difficult to detect, and PCB exposure does not explain the methylmercury neurotoxicity previously reported in this cohort.
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Affiliation(s)
- Philippe Grandjean
- Institute of Public Health, University of Southern Denmark, Odense, Denmark.
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