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Orlando MS, Love T, Harrington D, Dziorny AC, Shamlaye CF, Watson GE, van Wijngaarden E, Davidson PW, Myers GJ. The association of auditory function measures with low-level methylmercury from oceanic fish consumption and mercury vapor from amalgam: The Seychelles Child Development Study Nutrition 1 Cohort. Neurotoxicology 2023; 95:46-55. [PMID: 36621469 PMCID: PMC9998349 DOI: 10.1016/j.neuro.2022.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/21/2022] [Accepted: 12/29/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND Some authors have reported that low-level exposure to methylmercury (MeHg) adversely impacts measures of auditory function. These reports, however, are not consistent in their findings. Consequently, we examined auditory function in a population exposed to low-level methylmercury (MeHg) exposure from fish consumption and to mercury vapor (Hg0) from dental amalgams. We analyzed their associations with the participants hearing acuity, absolute and interwave ABR latencies, and otoacoustic emissions (distortion product/DPOAE and click evoked/CEOAE). DESIGN We administered an audiometry test battery to 246 participants from the Seychelles Child Development Study (SCDS) Nutrition Cohort 1 (NC1) at 9 years of age. The test battery included standard pure-tone audiometry, tympanometry, Auditory Brainstem Responses (ABR) and Distortion Product and Click Evoked Otoacoustic Emissions (DPOAE and CEOAE) testing. We measured prenatal MeHg exposure in maternal hair and postnatal MeHg in children's hair. We approximated prenatal Hg0 exposure using maternal amalgam surface area and postnatal Hg0 using children amalgam surface area. Complete exposure records and audiometric data were available on 210 participants and in them we analyzed the association of MeHg and Hg0 exposures with auditory outcomes using covariate-adjusted linear regression models adjusted for sex and tympanometric pressure. RESULTS Hg exposures were similar for both sexes. Seven of the 210 evaluable participants examined had either a mild (5) or moderate (2) hearing loss. Four had a mild monaural hearing loss and 3 had either a mild (1) or moderate (2) bilateral hearing loss. No participant had greater than a moderate hearing loss in either ear. Hg exposures were higher in participants with either a mild or moderate hearing loss, but these differences were not statistically significant. Among the 210 with complete data, neither prenatal nor postnatal MeHg nor Hg0 exposure was statistically significantly associated with any of the ABR endpoints (p > 0.05 for all 72 associations). Neither prenatal nor postnatal Hg0 exposure was associated with any of the OAE endpoints (p > 0.05). MeHg exposure was statistically associated with 6 of the 56 DPOAE endpoints (p-values between 0.0001 and 0.023), but none of the 40 CEOAE endpoints. Two of the associations occurred with prenatal MeHg exposures and 1 of those would suggest a beneficial effect. Four of the other associations occurred with postnatal MeHg exposures with only 2 found in left ears of both males and females and the other 2 in the left and right ear of females at only one frequency. CONCLUSION Overall, these data do not present a clear and consistent pattern to suggest that the auditory system is negatively affected by low-level methylmercury exposure due to dietary consumption of oceanic fish or mercury vapor exposure from dental amalgams.
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Affiliation(s)
- Mark S Orlando
- Department of Otolaryngology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA.
| | - Tanzy Love
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
| | - Donald Harrington
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
| | - Adam C Dziorny
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Biomedical Engineering, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
| | | | - Gene E Watson
- Eastman Institute for Oral Health, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
| | - Edwin van Wijngaarden
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Eastman Institute for Oral Health, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Community Health and Prevention, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
| | - Philip W Davidson
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Psychiatry, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
| | - Gary J Myers
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Neurology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Rochester, NY 14642, USA
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Movassagh H, Halchenko Y, Sampath V, Nygaard UC, Jackson B, Robbins D, Li Z, Nadeau KC, Karagas MR. Maternal gestational mercury exposure in relation to cord blood T cell alterations and placental gene expression signatures. ENVIRONMENTAL RESEARCH 2021; 201:111385. [PMID: 34129869 PMCID: PMC8478717 DOI: 10.1016/j.envres.2021.111385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
The immunotoxic impacts of mercury during early life is poorly understood. We investigated the associations between gestational mercury exposure and frequency of cord blood T cells as well as placental gene expression. Frequency of natural Treg cells was positively associated with prenatal and postpartum mercury toenail concentrations. Frequency of NKT and activated naïve Th cells was positively associated with prenatal toenail mercury concentrations and number of maternal silver-mercury dental amalgams, respectively. Placental gene expression analyses revealed distinct gene signatures associated with mercury exposure. Decreased placental expression of a histone demethylase, KDM4DL, was associated with both higher prenatal and postpartum maternal toenail mercury levels among male infants and remained statistically significant after adjustment for fish and seafood consumption. The results suggest that gestational exposure to mercury concentrations contribute to alterations in both T cells and gene expression in placenta at birth. These alterations may inform mechanisms of mercury immunotoxicity.
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Affiliation(s)
- Hesam Movassagh
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, USA
| | - Yuliya Halchenko
- Department of Epidemiology, Geisel School of Medicine and the Children's Environmental Health and Disease Prevention Research Center at Dartmouth; Hanover, NH, USA
| | - Vanitha Sampath
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, USA
| | - Unni C Nygaard
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, USA; Department of Environmental Health, Norwegian Institute of Public Health; Oslo, Norway
| | - Brian Jackson
- Department of Earth Sciences, Dartmouth College; Hanover, NH, USA
| | - David Robbins
- Department of Surgery, University of Miami, Miller School of Medicine; Miami, FL, USA
| | - Zhigang Li
- Department of Epidemiology, Geisel School of Medicine and the Children's Environmental Health and Disease Prevention Research Center at Dartmouth; Hanover, NH, USA
| | - Kari C Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, USA.
| | - Margaret R Karagas
- Department of Epidemiology, Geisel School of Medicine and the Children's Environmental Health and Disease Prevention Research Center at Dartmouth; Hanover, NH, USA
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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: 6] [Impact Index Per Article: 1.5] [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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Joubert BR, Mantooth SN, McAllister KA. Environmental Health Research in Africa: Important Progress and Promising Opportunities. Front Genet 2020; 10:1166. [PMID: 32010175 PMCID: PMC6977412 DOI: 10.3389/fgene.2019.01166] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 10/23/2019] [Indexed: 12/16/2022] Open
Abstract
The World Health Organization in 2016 estimated that over 20% of the global disease burden and deaths were attributed to modifiable environmental factors. However, data clearly characterizing the impact of environmental exposures and health endpoints in African populations is limited. To describe recent progress and identify important research gaps, we reviewed literature on environmental health research in African populations over the last decade, as well as research incorporating both genomic and environmental factors. We queried PubMed for peer-reviewed research articles, reviews, or books examining environmental exposures and health outcomes in human populations in Africa. Searches utilized medical subheading (MeSH) terms for environmental exposure categories listed in the March 2018 US National Report on Human Exposure to Environmental Chemicals, which includes chemicals with worldwide distributions. Our search strategy retrieved 540 relevant publications, with studies evaluating health impacts of ambient air pollution (n=105), indoor air pollution (n = 166), heavy metals (n = 130), pesticides (n = 95), dietary mold (n = 61), indoor mold (n = 9), per- and polyfluoroalkyl substances (PFASs, n = 0), electronic waste (n = 9), environmental phenols (n = 4), flame retardants (n = 8), and phthalates (n = 3), where publications could belong to more than one exposure category. Only 23 publications characterized both environmental and genomic risk factors. Cardiovascular and respiratory health endpoints impacted by air pollution were comparable to observations in other countries. Air pollution exposures unique to Africa and some other resource limited settings were dust and specific occupational exposures. Literature describing harmful health effects of metals, pesticides, and dietary mold represented a context unique to Africa. Studies of exposures to phthalates, PFASs, phenols, and flame retardants were very limited. These results underscore the need for further focus on current and emerging environmental and chemical health risks as well as better integration of genomic and environmental factors in African research studies. Environmental exposures with distinct routes of exposure, unique co-exposures and co-morbidities, combined with the extensive genomic diversity in Africa may lead to the identification of novel mechanisms underlying complex disease and promising potential for translation to global public health.
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Affiliation(s)
- Bonnie R Joubert
- National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | | | - Kimberly A McAllister
- National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
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Davidson PW, van Wijngaarden E, Shamlaye C, Strain JJ, Myers GJ. Putting findings from the Seychelles Child Development Study into perspective: The importance of a historical special issue of the Seychelles Medical and Dental Journal. Neurotoxicology 2020; 76:111-113. [PMID: 31706981 PMCID: PMC6980718 DOI: 10.1016/j.neuro.2019.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 10/25/2019] [Indexed: 11/20/2022]
Abstract
We are pleased to introduce this special issue of Neurotoxicology. It reproduces Volume 7, Number 1 of the Seychelles Medical and Dental Journal (SMDJ), initially published in November 2004. Publication of the SMDJ was discontinued in 2005 and the manuscripts it published are no longer accessible to the scientific community. The papers in this special issue lay the background for the Seychelles Child Development Study (SCDS) and provide valuable data on the MeHg exposures that occurred at Niigata, Japan. They are relevant to the ongoing debate over whether the consumption of fish and consequently low-level exposure to methylmercury (MeHg) is a risk to human health.
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Affiliation(s)
- P W Davidson
- University of Rochester School of Medicine and Dentistry, United States
| | - E van Wijngaarden
- University of Rochester School of Medicine and Dentistry, United States.
| | - C Shamlaye
- University of Rochester School of Medicine and Dentistry, United States
| | - J J Strain
- University of Rochester School of Medicine and Dentistry, United States
| | - G J Myers
- University of Rochester School of Medicine and Dentistry, United States
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Tatsuta N, Nakai K, Sakamoto M, Murata K, Satoh H. Methylmercury Exposure and Developmental Outcomes in Tohoku Study of Child Development at 18 Months of Age. TOXICS 2018; 6:toxics6030049. [PMID: 30134554 PMCID: PMC6161177 DOI: 10.3390/toxics6030049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 08/14/2018] [Accepted: 08/18/2018] [Indexed: 11/21/2022]
Abstract
Seafood is an important component in a healthy diet and may contain methylmercury or other contaminants. It is important to recognize the risks and benefits of consuming seafood. A longitudinal prospective birth cohort study has been conducted to clarify the effects of neurotoxicants on child development—the Tohoku Study of Child Development (TSCD) in Japan. TSCD comprises two cohorts; a polychlorinated biphenyls (PCB) cohort (urban area) and a methylmercury cohort (coastal area). Our previous results from the coastal area showed prenatal methylmercury exposure affected psychomotor development in 18-month-olds, and boys appear to be more vulnerable to the exposure than girls. In this report, we have added the urban area cohort and we reanalyzed the impact of prenatal exposure to methylmercury, which gave the same results as before. These findings suggest prenatal exposure to low levels methylmercury may have adverse effects on child development, especially in 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, Sendai 980-8575, Japan.
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
| | - Mineshi Sakamoto
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
- Environmental Health Section, Department of Environmental Science and Epidemiology, National Institute for Minamata Disease, Kumamoto 867-0008, Japan.
| | - Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine, Akita 010-8502, Japan.
| | - Hiroshi Satoh
- Environmental Health Science, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
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7
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Oliveira CS, Nogara PA, Ardisson-Araújo DMP, Aschner M, Rocha JBT, Dórea JG. Neurodevelopmental Effects of Mercury. ADVANCES IN NEUROTOXICOLOGY 2018; 2:27-86. [PMID: 32346667 PMCID: PMC7188190 DOI: 10.1016/bs.ant.2018.03.005] [Citation(s) in RCA: 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.
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Affiliation(s)
- Cláudia S Oliveira
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Pablo A Nogara
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Daniel M P Ardisson-Araújo
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
- Laboratório de Virologia de Insetos, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, NY, USA
| | - João B T Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - José G Dórea
- Professor Emeritus, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, DF, Brazil
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Tatsuta N, Murata K, Iwai-Shimada M, Yaginuma-Sakurai K, Satoh H, Nakai K. Psychomotor Ability in Children Prenatally Exposed to Methylmercury: The 18-Month Follow-Up of Tohoku Study of Child Development. TOHOKU J EXP MED 2017; 242:1-8. [PMID: 28484113 DOI: 10.1620/tjem.242.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fish contain nutrients essential to the developing fetal brain, but they are contaminated with methylmercury. The Tohoku Study of Child Development, now underway in the Sanriku coastal area of Miyagi prefecture, Japan, follows mother-child pairs to examine the risks and benefits of fish consumption during pregnancy, especially the effects of prenatal exposures to methylmercury, selenium, and docosahexaenoic acid (DHA) on child neurodevelopment. Children aged 18 months were administered the Bayley Scales of Infant Development second edition (BSID-II) and Kyoto Scale of Psychological Development (KSPD) in 2004-2008. Complete data of cord-blood total mercury (THg), cord-plasma selenium, maternal-plasma DHA, the above test scores, and confounders for 566 mother-child pairs were available. The median cord-blood THg level was 15.7 (range, 2.7-96.1) ng/g. Since the BSID-II and KSPD scores were significantly lower in the 285 boys than in the 281 girls, analyses were conducted separately. The Psychomotor Development Index (PDI) of BSID-II was significantly correlated with cord-blood THg only in the boys, and significance of the association remained unchanged after adjusting for possible confounders; i.e., a 10-fold increase in cord-blood THg was associated with a 8.3-point decrease in the score of the PDI. Other significant correlations of THg were not seen in the boys or girls. Selenium and DHA showed no significant correlations with the BSID-II or KSPD scores in either sex. In conclusion, intrauterine methylmercury exposure may affect psychomotor development, and boys appear to be more vulnerable to the exposure than girls.
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Affiliation(s)
- Nozomi Tatsuta
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine.,Department of Environmental Health Sciences, Akita University Graduate School of Medicine
| | - Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine
| | - Miyuki Iwai-Shimada
- Centre for Health and Environmental Risk Research, National Institute for Environmental Studies
| | - Kozue Yaginuma-Sakurai
- Department of Human Health and Nutrition, Shokei Gakuin University Faculty of Comprehensive Human Science
| | - Hiroshi Satoh
- Environmental Health Sciences, Tohoku University Graduate School of Medicine
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine
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Four or More Amalgam Fillings Correlate With Higher Blood Mercury Levels in Pregnant Women but Not High Enough to be of Health Concern. J Evid Based Dent Pract 2017; 17:139-141. [PMID: 28501064 DOI: 10.1016/j.jebdp.2017.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION Dental associations with blood mercury in pregnant women. Golding J, Steer CD, Gregory S, Lowery T, Hibbeln JR, Taylor CM. Community Dent Oral Epidemiol 2016; 44: 216-22. SOURCE OF FUNDING This study was funded by a combination of government (UK Medical Research Council), foundation/nonprofit (the Welcome Trust) and university (University of Bristol, UK) grants. TYPE OF STUDY/DESIGN Cross-sectional.
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10
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Pihlstrom BL. Selections From the Current Literature. J Am Dent Assoc 2016. [DOI: 10.1016/j.adaj.2016.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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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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Al-Saleh I, Nester M, Abduljabbar M, Al-Rouqi R, Eltabache C, Al-Rajudi T, Elkhatib R. Mercury (Hg) exposure and its effects on Saudi breastfed infant's neurodevelopment. Int J Hyg Environ Health 2016; 219:129-41. [DOI: 10.1016/j.ijheh.2015.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/18/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
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13
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Golding J, Steer CD, Gregory S, Lowery T, Hibbeln JR, Taylor CM. Dental associations with blood mercury in pregnant women. Community Dent Oral Epidemiol 2015; 44:216-22. [PMID: 26688340 PMCID: PMC4840325 DOI: 10.1111/cdoe.12208] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 11/16/2015] [Indexed: 12/01/2022]
Abstract
Objectives There is curiosity concerning the source of mercury that is absorbed into the mother's blood and which may affect the developing fetus. This study therefore sets out to determine the extent to which dental amalgam (DA) may contribute to total blood mercury (TBHg) levels of pregnant women in the UK. Methods Whole blood samples and information on diet and socio‐demographic factors were collected from pregnant women (n = 4484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The whole blood samples were assayed for total mercury levels using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP‐DRC‐MS), and the women were retrospectively asked about features of their dental care during the pregnancy. Linear regression was used to estimate the relative contributions of DA to TBHg levels (log‐transformed) based on R2 values, compared to the results from dietary and socio‐demographic variables. Results The contribution to the variance of the mothers' TBHg levels by dental variables was 6.47%, a figure comparable to the 8.75% shown for seafood consumption in this population. Dietary and dental variables explained 20.16% of the variance, with socio‐demographic variables contributing only a further 3.40%. The number of amalgams in the mouth at the start of pregnancy accounted for most of the variance in dental variables. Conclusions Dental amalgam contributes a comparable amount of variance in TBHg to seafood consumption in this population. However, because the measures of DA exposure were imprecise, these findings are likely to be an underestimate. There is no evidence to date in the literature that fetal exposures to mercury from maternal DAs have adverse effects on the developing child, but long‐term studies are warranted.
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Affiliation(s)
- Jean Golding
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Colin D Steer
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Steven Gregory
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Tony Lowery
- National Seafood Inspection Laboratory, National Marine Fisheries Service, National Oceanic & Atmospheric Administration, Pascagoula, MS, USA
| | - Joseph R Hibbeln
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Caroline M Taylor
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
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Dzwilewski KLC, Schantz SL. Prenatal chemical exposures and child language development. JOURNAL OF COMMUNICATION DISORDERS 2015; 57:41-65. [PMID: 26255253 PMCID: PMC4548902 DOI: 10.1016/j.jcomdis.2015.07.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 07/10/2015] [Accepted: 07/16/2015] [Indexed: 05/09/2023]
Abstract
UNLABELLED The goal of this review is to summarize the evidence that prenatal and/or early postnatal exposure to certain chemicals, both manmade (insulating materials, flame retardants, pesticides) and naturally occurring (e.g., lead, mercury), may be associated with delays or impairments in language development. We focus primarily on a subset of more extensively studied chemicals-polychlorinated biphenyls (PCBs), lead, and methyl mercury-for which a reasonable body of literature on neurodevelopmental outcomes is available. We also briefly summarize the smaller body of evidence for other chemicals including polybrominated diphenyl ether flame retardants (PBDEs) and organophosphate pesticides. Very few studies have used specific assessments of language development and function. Therefore, we included discussion of aspects of cognitive development such as overall intellectual functioning and verbal abilities that rely on language, as well as aspects of cognition such as verbal and auditory working memory that are critical underpinnings of language development. A high percentage of prospective birth cohort studies of PCBs, lead, and mercury have reported exposure-related reductions in overall IQ and/or verbal IQ that persist into middle or late childhood. Given these findings, it is important that clinicians and researchers in communication sciences and disorders are aware of the potential for environmental chemicals to impact language development. LEARNING OUTCOMES The goal of this review is to summarize the evidence that prenatal and/or early postnatal exposure to certain chemicals may be associated with delays or impairments in language development. Readers will gain an understanding of the literature suggesting that early exposure to polychlorinated biphenyls (PCBs), lead, and mercury may be associated with decrements in cognitive domains that depend on language or are critical for language development. We also briefly summarize the smaller body of evidence regarding polybrominated diphenyl ether flame retardants (PBDEs) and organophosphate pesticides. Very few studies of exposure to these chemicals have used specific assessments of language development; thus, further investigation is needed before changes in clinical practice can be suggested.
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Affiliation(s)
- Kelsey L C Dzwilewski
- University of Illinois at Urbana-Champaign, Neuroscience Program, 405 North Mathews Avenue, Urbana, IL 61801, USA.
| | - Susan L Schantz
- University of Illinois at Urbana-Champaign, Department of Comparative Biosciences, 2001 South Lincoln Avenue, Urbana, IL 61802, USA.
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15
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Abstract
BACKGROUND There continues to be public concern that mercury exposure and autism spectrum disorder (ASD) may be associated. The primary source of exposure to organic mercury in humans is to methylmercury from fish consumption. We evaluated the association between prenatal methylmercury exposure and ASD phenotype in children and adolescents in the Republic of Seychelles, where fish consumption is high. METHODS We administered the Social Communication Questionnaire to parents of a cohort of 1784 children, adolescents, and young adults. The Social Responsiveness Scale was administered to teachers of 537 cohort subjects at about 10 years of age. Prenatal exposure to methylmercury was measured in maternal hair samples collected at or near the time of birth. Multivariable regression models evaluated the relationship between prenatal methylmercury exposure and ASD phenotypic scores, adjusting for relevant covariates. RESULTS The mean prenatal methylmercury exposure for subjects in the analysis was 8.4 ppm (standard deviation [SD] = 5.7). The mean Social Communication Questionnaire score was 8.0 (SD = 4.4). The mean prenatal methylmercury exposure for subjects with Social Responsiveness Scale scores was 6.7 ppm (SD = 4.4) and the mean Social Responsiveness Scale score was 57.6 (SD = 26.8). No consistent association between prenatal methylmercury exposure and ASD screening instrument was found, using linear and nonlinear regression analyses. CONCLUSIONS Prenatal exposure to methylmercury was not associated with ASD phenotypic behaviors in our cohort of high fish consumers. Our findings contribute to the growing literature suggesting that exposure to methylmercury does not play an important role in the development of ASD phenotypic behavior.
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Donovan TE, Anderson M, Becker W, Cagna DR, Carr GB, Albouy JP, Metz J, Eichmiller F, McKee JR. Annual Review of selected dental literature: Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry. J Prosthet Dent 2013; 110:161-210. [DOI: 10.1016/s0022-3913(13)60358-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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17
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Watson GE, van Wijngaarden E, Love TMT, McSorley EM, Bonham MP, Mulhern MS, Yeates AJ, Davidson PW, Shamlaye CF, Strain JJ, Thurston SW, Harrington D, Zareba G, Wallace JMW, Myers GJ. Neurodevelopmental outcomes at 5 years in children exposed prenatally to maternal dental amalgam: the Seychelles Child Development Nutrition Study. Neurotoxicol Teratol 2013; 39:57-62. [PMID: 23856391 PMCID: PMC3917122 DOI: 10.1016/j.ntt.2013.07.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/12/2013] [Accepted: 07/02/2013] [Indexed: 11/19/2022]
Abstract
Limited human data are available to assess the association between prenatal mercury vapor (Hg⁰)) exposure from maternal dental amalgam restorations and neurodevelopment of children. We evaluated the association between maternal dental amalgam status during gestation and children's neurodevelopmental outcomes at 5 years in the Seychelles Child Development Nutrition Study (SCDNS). Maternal amalgam status was determined prospectively in a longitudinal cohort study examining the associations of prenatal exposure to nutrients and methylmercury (MeHg) with neurodevelopment. A total of 236 mother-child pairs initially enrolled in the SCDNS in 2001 were eligible to participate. Maternal amalgam status was measured as number of amalgam surfaces (the primary metric) and number of occlusal points. The neurodevelopmental assessment battery was comprised of age-appropriate tests of cognitive, language, and perceptual functions, and scholastic achievement. Linear regression analysis controlled for MeHg exposure, maternal fatty acid status, and other covariates relevant to child development. Maternal amalgam status evaluation yielded an average of 7.0 surfaces (range 0-28) and 11.0 occlusal points (range 0-40) during pregnancy. Neither the number of maternal amalgam surfaces nor occlusal points were associated with any outcome. Our findings do not provide evidence to support a relationship between prenatal exposure to Hg⁰ from maternal dental amalgam and neurodevelopmental outcomes in children at 5 years of age.
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Affiliation(s)
- Gene E Watson
- Eastman Institute for Oral Health, University of Rochester, 601 Elmwood Avenue, Box 705, Rochester, NY 14642, USA; Department of Environmental Medicine, University of Rochester, 601 Elmwood Avenue, Box EHSC, Rochester, NY 14642, USA; Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Box 705, Rochester, NY 14642, USA.
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Al-Saleh I, Abduljabbar M, Al-Rouqi R, Elkhatib R, Alshabbaheen A, Shinwari N. Mercury (Hg) exposure in breast-fed infants and their mothers and the evidence of oxidative stress. Biol Trace Elem Res 2013; 153:145-54. [PMID: 23661328 DOI: 10.1007/s12011-013-9687-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/25/2013] [Indexed: 11/24/2022]
Abstract
The objective of this work was to assess exposure to mercury (Hg) and its induction of oxidative stress in 155 healthy lactating Saudi mothers and their infants. Samples of breast milk and blood were collected from the mothers, while urine was taken from both infants and mothers. Both urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) were measured in mothers and infants as biomarkers of oxidative stress. The mean concentration of Hg in breast milk was 1.19 μg/L (range 0.012-6.44 μg/L) with only one mother having Hg >4 μg/L, the upper limit established by the US Agency for Toxic Substance and Disease Registry. However, 57.4 % had Hg ≥1 μg/L, the background level for Hg in human milk. The mean urinary Hg corrected for creatinine (Hg-C) in mothers and infants was 1.47 and 7.90 μg/g creatinine, respectively, with a significant correlation between the two (p < 0.001). Urinary Hg levels over 5 μg/g creatinine (the background level in an unexposed population) were found in 3.3 % of mothers and 50.1 % of infants. None of the mothers had total blood Hg above the US Environmental Protection Agency's maximum reference dose of 5.8 μg/L. No correlation was noted between urinary Hg in infants and Hg in breast milk (p > 0.05). Hg in breast milk, though, was associated with Hg in blood (p < 0.001), suggesting the efficient transfer of Hg from blood to milk. Hg in the breast milk of mothers and in the urine of infants affected the excretion of urinary MDA and 8-OHdG, respectively, in a dose-related manner. These findings reveal for the first time lactational exposure to Hg-induced oxidative stress in breast-fed infants, which may play a role in pathogenesis, particularly during neurodevelopment. This will also contribute to the debate over the benefits of breast milk versus the adverse effects of exposure to pollutants. Nevertheless, breastfeeding should not be discouraged, but efforts should be made to identify and eliminate the source of Hg exposure in the population.
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Affiliation(s)
- Iman Al-Saleh
- Environmental Health Section, Biological and Medical Research Department, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh 11211, Saudi Arabia.
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