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Chemelo VS, Bittencourt LO, Nascimento PC, Paiva MF, Delbem ACB, Pessan JP, do Espírito Santo AR, Albuquerque ARL, Angélica RS, Crespo-Lopez ME, Pessanha S, Aschner M, Lima RR. Maternal methylmercury exposure during early-life periods adversely affects mature enamel structure of offspring rats at human exposure levels: a concern for oral health. Front Public Health 2023; 11:1183308. [PMID: 37457266 PMCID: PMC10348892 DOI: 10.3389/fpubh.2023.1183308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/15/2023] [Indexed: 07/18/2023] Open
Abstract
Although there are many studies on the health effects of methylmercury (MeHg) toxicity during in utero and early development, little is known about its effects on mineralized tissues present in the oral cavity, such as enamel structure. Therefore, this study evaluated the effects of MeHg exposure on the physico-chemical, ultrastructural and functional properties of mature tooth enamel. Specifically, we studied offspring of mothers exposed to MeHg during the prenatal and postnatal periods which are the developmental stages associated with tooth enamel formation. Female rats were exposed to MeHg at a dose of 40 μg/kg/day for 42 days of pregnancy and lactation. The enamel of offspring was analyzed by (1) Fourier Transform Infrared Spectroscopy and Raman to assess physicochemical composition, (2) Scanning Electron Microscopy for ultrastructural evaluation, (3) Transmitted Polarizing Light Microscopy for analysis of the enamel extracellular matrix, and (4) resistance and hardness were evaluated by microhardness. The results showed that MeHg exposure during this sensitive enamel formation period induced changes in inorganic and organic content and enamel prisms ultrastructure alterations and disturbed the organic extracellular matrix due to a decreased enamel strength. These novel findings establish for the first time that maternal exposure to MeHg pre and postnatal promoted relevant changes in mature enamel of their offspring rats.
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Affiliation(s)
- Victória Santos Chemelo
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil
| | - Priscila Cunha Nascimento
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil
| | - Mayra Frasson Paiva
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Araçatuba, Brazil
| | - Alberto Carlos Botazzo Delbem
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Araçatuba, Brazil
| | - Juliano Pelim Pessan
- Department of Preventive and Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Araçatuba, Brazil
| | - Alexandre Ribeiro do Espírito Santo
- Laboratory of Histotechnology and Tissue Biology, Department of Biomorphology, Institute of Health Sciences, Federal University of Bahia (UFBA), Salvador, Bahia, Brazil
| | | | - Rômulo Simões Angélica
- Laboratory of X-Ray Diffraction, Institute of Geosciences, Federal University of Pará, Belém, Pará, Brazil
| | - Maria Elena Crespo-Lopez
- Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil
| | - Sofia Pessanha
- Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics, NOVA School of Science and Technology, Caparica, Portugal
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil
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2
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de Assis Araujo MS, Froes-Asmus CIR, de Figueiredo ND, Camara VM, Luiz RR, Prata-Barbosa A, Martins MM, Jacob SDC, dos Santos LMG, Vicentini Neto SA, de Rezende Filho JF, Amim Junior J. Prenatal Exposure to Metals and Neurodevelopment in Infants at Six Months: Rio Birth Cohort Study of Environmental Exposure and Childhood Development (PIPA Project). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:4295. [PMID: 35409976 PMCID: PMC8998578 DOI: 10.3390/ijerph19074295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/26/2022] [Accepted: 03/26/2022] [Indexed: 11/17/2022]
Abstract
The PIPA Project is a prospective birth cohort study based in Rio de Janeiro, Brazil, whose pilot study was carried out between October 2017 and August 2018. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) concentrations were determined in maternal (n = 49) and umbilical cord blood (n = 46). The Denver Developmental Screening Test II (DDST-II) was applied in 50 six-month-old infants. Metals were detected in 100% of the mother and newborn samples above the limits of detection. Maternal blood lead concentrations were higher in premature newborns (GM: 5.72 µg/dL; p = 0.05). One-third of the infants (n = 17-35.4%) exhibited at least one fail in the neurodevelopment evaluation (fail group). Maternal blood arsenic concentrations were significantly (p = 0.03) higher in the "fail group" (GM: 11.85 µg/L) compared to infants who did not fail (not fail group) (GM: 8.47 µg/L). Maternal and umbilical cord blood arsenic concentrations were higher in all Denver Test's domains in the "fail group", albeit non-statistically significant, showing a tendency for the gross motor domain and maternal blood (p = 0.07). These findings indicate the need to further investigate the toxic effects of prenatal exposure to metals on infant neurodevelopment.
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Affiliation(s)
| | - Carmen Ildes Rodrigues Froes-Asmus
- Postgraduate Program in Perinatal Health, Faculty of Medicine, Maternity School of Rio de Janeiro, Federal University of Rio de Janeiro, Rio de Janeiro 22240-000, Brazil; (C.I.R.F.-A.); (N.D.d.F.); (A.P.-B.); (J.F.d.R.F.); (J.A.J.)
| | - Nataly Damasceno de Figueiredo
- Postgraduate Program in Perinatal Health, Faculty of Medicine, Maternity School of Rio de Janeiro, Federal University of Rio de Janeiro, Rio de Janeiro 22240-000, Brazil; (C.I.R.F.-A.); (N.D.d.F.); (A.P.-B.); (J.F.d.R.F.); (J.A.J.)
| | - Volney Magalhães Camara
- Public Health Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21941-592, Brazil; (V.M.C.); (R.R.L.)
| | - Ronir Raggio Luiz
- Public Health Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21941-592, Brazil; (V.M.C.); (R.R.L.)
| | - Arnaldo Prata-Barbosa
- Postgraduate Program in Perinatal Health, Faculty of Medicine, Maternity School of Rio de Janeiro, Federal University of Rio de Janeiro, Rio de Janeiro 22240-000, Brazil; (C.I.R.F.-A.); (N.D.d.F.); (A.P.-B.); (J.F.d.R.F.); (J.A.J.)
- D’Or Institute for Research & Education (IDOR), Rio de Janeiro 22281-100, Brazil
| | - Marlos Melo Martins
- School Maternity Hospital, Federal University of Rio de Janeiro, Rio de Janeiro 22240-000, Brazil;
| | - Silvana do Couto Jacob
- Oswaldo Cruz Foundation, National Institute of Quality Control in Health, Rio de Janeiro 21040-900, Brazil; (S.d.C.J.); (L.M.G.d.S.); (S.A.V.N.)
| | - Lisia Maria Gobbo dos Santos
- Oswaldo Cruz Foundation, National Institute of Quality Control in Health, Rio de Janeiro 21040-900, Brazil; (S.d.C.J.); (L.M.G.d.S.); (S.A.V.N.)
| | - Santos Alves Vicentini Neto
- Oswaldo Cruz Foundation, National Institute of Quality Control in Health, Rio de Janeiro 21040-900, Brazil; (S.d.C.J.); (L.M.G.d.S.); (S.A.V.N.)
| | - Jorge Fonte de Rezende Filho
- Postgraduate Program in Perinatal Health, Faculty of Medicine, Maternity School of Rio de Janeiro, Federal University of Rio de Janeiro, Rio de Janeiro 22240-000, Brazil; (C.I.R.F.-A.); (N.D.d.F.); (A.P.-B.); (J.F.d.R.F.); (J.A.J.)
| | - Joffre Amim Junior
- Postgraduate Program in Perinatal Health, Faculty of Medicine, Maternity School of Rio de Janeiro, Federal University of Rio de Janeiro, Rio de Janeiro 22240-000, Brazil; (C.I.R.F.-A.); (N.D.d.F.); (A.P.-B.); (J.F.d.R.F.); (J.A.J.)
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3
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Heng YY, Asad I, Coleman B, Menard L, Benki-Nugent S, Hussein Were F, Karr CJ, McHenry MS. Heavy metals and neurodevelopment of children in low and middle-income countries: A systematic review. PLoS One 2022; 17:e0265536. [PMID: 35358213 PMCID: PMC8970501 DOI: 10.1371/journal.pone.0265536] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 03/03/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The presence of harmful environmental exposures, which disproportionately affects low-and-middle income countries (LMICs), contributes to >25% of deaths and diseases worldwide and detrimentally affects child neurodevelopment. Few resources succinctly summarize the existing literature on this topic. Our objective is to systematically review and characterize the evidence regarding the relationship between heavy metals and neurodevelopment of children in LMICs. METHODS We conducted a medical librarian-curated search on multiple online databases to identify articles that included individuals <18 years living in a LMIC, quantitatively measured exposure to a heavy metal (either prenatal or postnatal), and used a standardized measurement of neurodevelopment (i.e. cognitive, language, motor, and behavior). Reviews, editorials, or case studies were excluded. Results were analyzed qualitatively, and quality was assessed. RESULTS Of the 18,043 screened articles, 298 full-text articles were reviewed, and 100 articles met inclusion criteria. The included studies represented data from 19 LMICs, only one of which was classified as a low-income country. Ninety-four percent of postnatal lead and all postnatal manganese studies showed a negative association with metal exposure and neurodevelopment, which were the strongest relationships among the metals studied. Postnatal exposure of mercury was associated with poor neurodevelopment in only half of studies. Limited data on postnatal arsenic and cadmium suggests an association with worse neurodevelopment. Findings were mixed for prenatal arsenic and lead, although some evidence supports that the neurotoxicity of lead was amplified in the presence of manganese. CONCLUSIONS AND POTENTIAL IMPACT We found that lead and manganese appear to consistently have a detrimental effect on the neurodevelopment of children, and more evidence is needed for mercury, arsenic, and cadmium. Better characterization of these effects can motivate and inform prioritization of much needed international policies and programs to reduce heavy metal exposures for young children within LMICs.
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Affiliation(s)
- Yi Yan Heng
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Iqra Asad
- School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
| | - Bailey Coleman
- School of Health and Human Sciences, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
| | - Laura Menard
- Ruth Lilly Medical Library, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Sarah Benki-Nugent
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Faridah Hussein Were
- Department of Chemistry, College of Biological and Physical Sciences of the University of Nairobi, Nairobi, Kenya
| | - Catherine J. Karr
- Department of Environmental and Occupational Health Sciences, Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Megan S McHenry
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
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4
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Dack K, Fell M, Taylor CM, Havdahl A, Lewis SJ. Prenatal Mercury Exposure and Neurodevelopment up to the Age of 5 Years: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19041976. [PMID: 35206164 PMCID: PMC8871549 DOI: 10.3390/ijerph19041976] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 11/29/2022]
Abstract
Neurodevelopmental delays can interfere with children’s engagement with the world and further development, and may have negative consequences into adulthood. Mercury is highly toxic and may negatively influence neurodevelopment because it can freely cross the placenta and accumulate in the fetal brain. We searched four publication databases (Embase, PsycINFO, PubMed/MEDLINE, Scopus) for studies examining the relationship between early life mercury exposure and scores on neurodevelopmental performance measures in children aged 0 to 5 years old. Study quality was assessed using the National Institutes of Health (NIH) Quality Assessment Tool. Thirty-two prospective studies were included in the review. Neurodevelopmental performance was measured using 23 different scales, most commonly the Bayley Scales of Infant and Toddler Development (BSID). In most cases, the evidence for an association between mercury and neurodevelopment was weak. There did not appear to be exceptions for particular childhood ages, outcome scales, or mercury levels. The small number of results to the contrary were more likely to be studies which did not meet our high-quality criteria, and could be a consequence of multiple testing, selection bias, or incomplete confounder adjustment. Based on current evidence, dietary mercury exposure during pregnancy is unlikely to be a risk factor for low neurodevelopmental functioning in early childhood.
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Affiliation(s)
- Kyle Dack
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol BS8 1TH, UK
- Correspondence:
| | - Matthew Fell
- Cleft Collective, University of Bristol, Bristol BS8 1TH, UK;
| | - Caroline M. Taylor
- Centre for Academic Child Health, Bristol Medical School, University of Bristol, Bristol BS8 1TH, UK;
| | - Alexandra Havdahl
- Department of Mental Disorders, Norwegian Institute of Public Health, 0213 Oslo, Norway;
- Nic Waals Institute, Lovisenberg Diaconal Hospital, 0853 Oslo, Norway
| | - Sarah J. Lewis
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol BS8 1TH, UK;
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5
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Dórea JG. Exposure to environmental neurotoxic substances and neurodevelopment in children from Latin America and the Caribbean. ENVIRONMENTAL RESEARCH 2021; 192:110199. [PMID: 32941839 DOI: 10.1016/j.envres.2020.110199] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 05/24/2023]
Abstract
Environmental (and occupational) exposure to neurotoxic substances is a worldwide problem that can affect children's neurodevelopment (ND). In Latin American and Caribbean (LAC) countries there are over 300 million children living under the threat of neurodevelopmental delays due to toxic environmental exposure. Large industrial centers, intense mining and agricultural activities, along with changing complex ecosystems constitute a mosaic that drives contamination of air, water and the food chain. Neurotoxic contaminants such as pesticides (organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, and manganese fungicides), chemicals of industrial use (phthalates), and metals (Hg, Pb, Al, As, F, Cd, Mo, Mn) are at the center of environmental exposure studies. Exposure to neurotoxic substances singly or in combination with other compounds or socioeconomic stressors (maternal education, socio-economic and nutritional status) intertwined with occupational and para-occupational exposure can affect ND (motor, cognition, behavior) of children. Significant negative effects of pesticides and neurotoxic elements on ND were found in all studied countries, affecting especially the less-privileged children from laboring families. Studies showed that exposures to the neurotoxicants in human milk are secondary to their more lasting effects during prenatal exposure. This review integrates exposure (prenatal and breastfeeding), metabolism, and ND effects of neurotoxicants. It highlights the overwhelming evidence showing that current levels of exposures are hazardous and detrimental to children's ND in LAC countries. The evidence indicates that a reduction in neurotoxicant exposure is essential to protect children's ND. Therefore, it is urgent to adopt policies and actions that prevent and remediate region-specific children's ND issues.
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Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília, 70919-970, DF, Brazil.
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6
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Villagomez AN, Muñoz FM, Peterson RL, Colbert AM, Gladstone M, MacDonald B, Wilson R, Fairlie L, Gerner GJ, Patterson J, Boghossian NS, Burton VJ, Cortés M, Katikaneni LD, Larson JCG, Angulo AS, Joshi J, Nesin M, Padula MA, Kochhar S, Connery AK. Neurodevelopmental delay: Case definition & guidelines for data collection, analysis, and presentation of immunization safety data. Vaccine 2019; 37:7623-7641. [PMID: 31783983 PMCID: PMC6899448 DOI: 10.1016/j.vaccine.2019.05.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/09/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Adrienne N Villagomez
- University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital of Colorado, Aurora, CO, USA
| | - Flor M Muñoz
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Robin L Peterson
- University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital of Colorado, Aurora, CO, USA
| | - Alison M Colbert
- University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital of Colorado, Aurora, CO, USA
| | - Melissa Gladstone
- Department of Women and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | | | - Rebecca Wilson
- University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital of Colorado, Aurora, CO, USA
| | - Lee Fairlie
- Wits Reproductive Health and HIV Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Gwendolyn J Gerner
- Kennedy Krieger Institute, Baltimore, MD, USA; Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jackie Patterson
- University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Nansi S Boghossian
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - Vera Joanna Burton
- Kennedy Krieger Institute, Baltimore, MD, USA; Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | | | - Jennifer C G Larson
- Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI, USA
| | - Abigail S Angulo
- University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital of Colorado, Aurora, CO, USA
| | - Jyoti Joshi
- Center for Disease Dynamics Economics & Policy, Amity Institute of Public Health, Amity University, India
| | - Mirjana Nesin
- Division of Microbiology and Infectious Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michael A Padula
- Children's Hospital of Philadelphia, Department of Pediatrics, Philadelphia, PA, USA
| | - Sonali Kochhar
- Global Healthcare Consulting, India; University of Washington, Seattle, USA; Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Amy K Connery
- University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital of Colorado, Aurora, CO, USA.
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7
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Data relating neurodevelopment of exclusively breastfed children of urban mothers and pre- and post-natal mercury exposure. Data Brief 2019; 25:104283. [PMID: 31463344 PMCID: PMC6706763 DOI: 10.1016/j.dib.2019.104283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/25/2019] [Accepted: 07/12/2019] [Indexed: 11/21/2022] Open
Abstract
A cohort of 100 exclusively breastfed children was formed to study association between neurodevelopment and Hg exposure [1]. Detailed questionnaires were administered by trained interviewers to the mothers, and measurements of early child development were collected at 6, 36 and 60 months by trained nurses and psychologists using the Gesell Developmental Schedules. The association between prenatal and postnatal organic Hg (methyl-Hg from fish consumption and ethyl-Hg from Thimerosal-containing vaccine) exposures with Gesell scores of the four domains [Adaptive ability, Language development, Motor abilities (gross motor), and Personal-social ability] were studied in preschool children.
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8
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Dórea JG. Multiple low-level exposures: Hg interactions with co-occurring neurotoxic substances in early life. Biochim Biophys Acta Gen Subj 2018; 1863:129243. [PMID: 30385391 DOI: 10.1016/j.bbagen.2018.10.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/01/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022]
Abstract
All chemical forms of Hg can affect neurodevelopment; however, low levels of organic Hg (methylmercury-MeHg and ethylmercury-EtHg in Thimerosal-containing vaccines, hereafter 'TCV') exposures during early life (pregnancy and lactation) co-occur with other environmental neurotoxic substances. These neurotoxicants may act in parallel, synergistically, or antagonistically to Hg. Nevertheless, the risks of neurotoxicity associated with multiple neuro-toxicants depend on type, time, combinations of exposure, and environmental and/or genetic-associated factors. Neurological developmental disorders, delays in cognition and behavioral outcomes associated with multiple exposures (which include Hg) may show transient or lasting outcomes depending on constitutional and/or environmental factors that can interact to neutralize, aggravate or attenuate these effects; often these studies are challenging to interpret. During pregnancy and lactation, fish-MeHg exposure is frequently confounded with the opposing effects of neuroactive nutrients (in fish) that lead to positive, negative, or no effects on neurobehavioral tests. In infancy, exposures to acute binary mixtures (TCV- EtHg and Al-adjuvants in infant immunizations) are associated with increased risks of tics and other developmental disorders. Despite the certitude that promulgates single environmental neurotoxicants, empirical comparisons of combined exposures indicate that Hg-related outcome is uneven. Hg in combination with other neurotoxic mixtures may elevate risks of neurotoxicity, but these risks arise in circumstances that are not yet predictable. Therefore, to achieve the goals of the Minamata treaty and to safeguard the health of children, low levels of mercury exposure (in any chemical form) needs to be further reduced whether the source is environmental (air- and food-borne) or iatrogenic (pediatric TCVs).
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Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília 70919-970, DF, Brazil..
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9
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Dórea JG. Low-dose Thimerosal (ethyl-mercury) is still used in infants` vaccines: Should we be concerned with this form of exposure? J Trace Elem Med Biol 2018; 49:134-139. [PMID: 29895363 DOI: 10.1016/j.jtemb.2018.05.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 05/16/2018] [Indexed: 12/25/2022]
Abstract
In developing countries, Thimerosal-containing vaccines (TCV) are the main causes of organic Hg exposure for newborns, neonates, and infants immunized with TCV. This article addresses early-life exposure to this unique organic mercury compound (ethylmercury-EtHg) and the risks of its exposure. English language studies pertaining to Thimerosal/EtHg toxicity and exposure during early life were searched in PubMed; and, those publications judged to be relevant to the topic of this review were selected. The risk from the neurotoxic effects of pre- and post-natal Hg exposures depend, in part, on aggravating or attenuating environmental and/or genetic-associated factors. Health authorities in charge of controlling infectious disease dismiss the toxicology of mercury (immunological and subtle neurological effects as insignificant) related to low-dose Thimerosal. The review addresses the evidence that brings into question the safety of Thimerosal that is still present in vaccines given to pregnant women, infants, and children in developing countries, and recognizes the ethical imperative to extend the use of Thimerosal-free vaccines to developing countries, not just developed countries.
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Affiliation(s)
- José G Dórea
- Health Sciences, Universidade de Brasília, Brasília, 70919-970, DF, Brazil.
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10
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LaKind JS, Lehmann GM, Davis MH, Hines EP, Marchitti SA, Alcala C, Lorber M. Infant Dietary Exposures to Environmental Chemicals and Infant/Child Health: A Critical Assessment of the Literature. ENVIRONMENTAL HEALTH PERSPECTIVES 2018; 126:96002. [PMID: 30256157 PMCID: PMC6375563 DOI: 10.1289/ehp1954] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 08/02/2018] [Accepted: 08/13/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND The benefits of breastfeeding to the infant and mother have been well documented. It is also well known that breast milk contains environmental chemicals, and numerous epidemiological studies have explored relationships between background levels of chemicals in breast milk and health outcomes in infants and children. OBJECTIVES In this paper, we examine epidemiological literature to address the following question: Are infant exposures to background levels of environmental chemicals in breast milk and formula associated with adverse health effects? We critically review this literature a) to explore whether exposure-outcome associations are observed across studies, and b) to assess the literature quality. METHODS We reviewed literature identified from electronic literature searches. We explored whether exposure-outcome associations are observed across studies by assessing the quality (using a modified version of a previously published quality assessment tool), consistency, and strengths and weaknesses in the literature. The epidemiological literature included cohorts from several countries and examined infants/children either once or multiple times over weeks to years. Health outcomes included four broad categories: growth and maturation, morbidity, biomarkers, and neurodevelopment. RESULTS The available literature does not provide conclusive evidence of consistent or clinically relevant health consequences to infants exposed to environmental chemicals in breast milk at background levels. CONCLUSIONS It is clear that more research would better inform our understanding of the potential for health impacts from infant dietary exposures to environmental chemicals. A critical data gap is a lack of research on environmental chemicals in formula and infant/child health outcomes. https://doi.org/10.1289/EHP1954.
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Affiliation(s)
- Judy S LaKind
- 1 LaKind Associates, LLC, Catonsville, Maryland, USA
- 2 Department of Epidemiology and Public Health, University of Maryland School of Medicine , Baltimore, Maryland, USA
| | - Geniece M Lehmann
- 3 Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Research Triangle Park , North Carolina, USA
| | - Matthew H Davis
- 4 Office of Children's Health Protection, U.S. EPA, Washington, District of Columbia, USA
| | - Erin P Hines
- 3 Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Research Triangle Park , North Carolina, USA
| | - Satori A Marchitti
- 5 Oak Ridge Institute for Science and Education (ORISE), ORD, U.S. EPA, Athens, Georgia, USA
| | - Cecilia Alcala
- 6 Association of Schools and Programs of Public Health (ASPPH), ORD, U.S. EPA, Washington, District of Columbia, USA
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11
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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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Froes Asmus CIR, Camara VM, Landrigan PJ, Claudio L. A Systematic Review of Children's Environmental Health in Brazil. Ann Glob Health 2018; 82:132-48. [PMID: 27325071 DOI: 10.1016/j.aogh.2016.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
In the region of the Americas, approximately 100,000 children under the age of 5 years die each year due to environmental hazards. Brazil, due to its large size and wide range of environmental challenges, presents numerous hazards to children's health. The aim of this study was to systematically review the scientific literature that describes children's exposures to environmental pollutants in Brazil and their effects on Brazilian children's health. A systematic review of the scientific literature was performed without language restrictions and time of publication (years). The literature search was conducted in the following key resources: PubMed (MEDLINE), Scopus and Web of Science with the MeSH Terms: Environmental exposure AND Brazil (filters: Human, Child [birth to 18 years] and Affiliation Author). The Virtual Health Library was also employed to access the databases Scielo and Lilacs. The search strategy was [DeCS Terms]: Child OR adolescent AND Environmental exposure AND Brazil. Health effects in children associated with exposure to environmental pollutants in Brazil were reported in 74 studies, during the period between 1995 and 2015. The most frequently cited effect was hospital admission for respiratory causes including wheezing, asthma, and pneumonia among children living in areas with high concentrations of air pollutants. A broad spectrum of other health effects possibly linked to pollutants also was found such as prematurity, low birth weight, congenital abnormality (cryptorchidism, hypospadia, micropenis), poor performance in tests of psychomotor and mental development, and behavioral problems. Exposure to pesticides in utero and postnatally was associated with a high risk for leukemia in children <2 years old. These results show that there is a need in Brazil for stricter monitoring of pollutant emissions and for health surveillance programs especially among vulnerable populations such as pregnant women and young children.
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Affiliation(s)
- Carmen I R Froes Asmus
- Public Health Institute, School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Preventive Medicine Department, Icahn School of Medicine of Mount Sinai, New York, NY.
| | - Volney M Camara
- Public Health Institute, School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Philip J Landrigan
- Preventive Medicine Department, Icahn School of Medicine of Mount Sinai, New York, NY; Arnhold Global Health Institute, Icahn School of Medicine of Mount Sinai, New York, NY
| | - Luz Claudio
- Preventive Medicine Department, Icahn School of Medicine of Mount Sinai, New York, NY
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Kim BM, Chen MH, Chen PC, Park H, Ha M, Kim Y, Hong YC, Kim YJ, Ha EH. Path analysis of prenatal mercury levels and birth weights in Korean and Taiwanese birth cohorts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 605-606:1003-1010. [PMID: 28693105 DOI: 10.1016/j.scitotenv.2017.06.151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/07/2017] [Accepted: 06/19/2017] [Indexed: 05/20/2023]
Abstract
Prospective cohort studies of the effect of mercury (Hg) exposure on birth weight have shown conflicting results. We combined data from Taiwanese and Korean birth cohorts, and assessed the effects of Hg exposure on birth weight. The first cohort was drawn from the Mothers and Children's Environmental Health (MOCEH) study performed in Korea from 2006 to 2010. The second cohort was enrolled from 2004 to 2005 and included singleton term births from the Taiwan Birth Panel Study (TBPS). In total, 1147 pregnant women were included in this study. A pooled analysis was performed to obtain combined estimates of the association between prenatal total Hg exposure and birth weight. A significant negative association between maternal and cord blood Hg and birth weight in the high-Hg group (Hg level>25th percentile) was detected (maternal blood: β=-0.056; 95% CI, -0.100 to -0.013, cord blood: β=-0.075; 95% CI, -0.121 to -0.028). Hg level showed a negative coefficient in the path analysis, indicating an adverse effect on birth weight (total effects: β=-0.177, P=0.01 in MOCEH, β=-0.204, P=0.03 in TBPS), but fish consumption exhibited a strong positive coefficient. In addition, fish consumption exerted a significant indirect effect on birth weight through exposure to cord blood Hg. Exposure to hazardous contaminants and beneficial nutrients may be highly correlated in those who frequently consume fish. Moreover, Hg in cord blood may adversely affect birth weight.
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Affiliation(s)
- Byung-Mi Kim
- Division of Cancer Prevention, National Cancer Control Institute, National Cancer Center, Goyang, Republic of Korea
| | - Mei-Huei Chen
- Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Department of Pediatrics, National Taiwan University Hospital Yun-Lin Branch, Yunlin County, Taiwan; Department of Pediatrics, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Pau-Chung Chen
- Occupational Health Section, Environmental Protection Center, National Taiwan University, Taiwan
| | - Hyesook Park
- Department of Preventive Medicine, School of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea
| | - Mina Ha
- Department of Preventive 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
- Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Ju Kim
- Department of Obstetrics Medicine, School of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea
| | - Eun-Hee Ha
- Department of Preventive Medicine, School of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea.
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Dórea JG. Abating Mercury Exposure in Young Children Should Include Thimerosal-Free Vaccines. Neurochem Res 2017; 42:2673-2685. [PMID: 28439753 DOI: 10.1007/s11064-017-2277-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/11/2017] [Accepted: 04/19/2017] [Indexed: 12/27/2022]
Abstract
Pediatric immunization is essential to prevent, control and eradicate children`s infectious diseases. Newborns and infants in less developed countries have a concentrated schedule of Thimerosal-containing vaccines (TCVs); pregnant mothers are also immunized with TCVs. Metabolic changes during early development are demonstrably an important risk factor for ethylmercury (EtHg) effects on neurodevelopment, while exposure to Thimerosal sensitizes susceptible individuals to life-long contact dermatitis. Concerns regarding toxicity of Hg have moved rich nations to withdraw it from medicines and, in particular, Thimerosal from pediatric vaccines; it has been more than 20 years since rich countries started using Thimerosal-free vaccines. TCVs and Thimerosal-free vaccines show dissimilar profiles of adverse effects. Thimerosal-free vaccines have shown a decrease in contact dermatitis, while TCVs showed a significant association with increased risk of tic disorders; in some circumstances, EtHg in combination with other neurotoxic substances negatively impacted neurobehavioral tests. In studies that explored vaccines and risk of tics, Thimerosal was a necessary factor. However, when the binary exposure to organic Hg forms (TCV-EtHg and fish-MeHg) was considered, effects on neurobehavioral tests were inconsistent. CONCLUSIONS (a) The indiscriminate use of pediatric-TCVs in less developed countries carries an unjustifiable and excessive EtHg exposure with an unnecessary risk of neurotoxicity to the developing brain; (b) measurable benefits (of Thimerosal-free) and measurable risks of tic disorders have been associated with the (Thimerosal-containing) type of vaccine;
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Affiliation(s)
- José G Dórea
- Professor Emeritus, Faculty of Health Sciences, Universidade de Brasília, 70919-970, Brasília, DF, Brazil.
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Contaminación por mercurio de leche materna de madres lactantes de municipios de Antioquia con explotación minera de oro. BIOMEDICA 2017; 38:19-29. [DOI: 10.7705/biomedica.v38i0.3609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/04/2016] [Accepted: 03/15/2017] [Indexed: 02/04/2023]
Abstract
Introducción. La leche materna es esencial para el desarrollo del ser humano, pero puede contener sustancias tóxicas provenientes de la contaminación ambiental, especialmente en las áreas mineras.Objetivo. Determinar la prevalencia de la contaminación con mercurio de la leche materna de mujeres lactantes residentes en los municipios con explotación minera de oro.Materiales y métodos. Se hizo un estudio transversal de 150 madres lactantes de cuatro municipios mineros de Antioquia (El Bagre, Segovia, Remedios y Zaragoza), a quienes se les hizo una encuesta sobre factores sociodemográficos, ocupacionales y ambientales relacionados con el mercurio, y se les tomaron muestras de leche materna, de orina y de cabello. Se calculó el promedio de la concentración de mercurio y las prevalencias municipales de contaminación.Resultados. El promedio de la concentración de mercurio en la leche materna fue de 2,5 (± desviación estándar 9,2) μg/L. La prevalencia de muestras de leche materna con niveles altos de mercurio fue de 11,7 %.Conclusión. En este estudio se evidencia un grave problema en las regiones mineras auríferas de Antioquia por el efecto de la contaminación con mercurio en sectores de la población más vulnerable.
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Dórea JG. Low-dose Thimerosal in pediatric vaccines: Adverse effects in perspective. ENVIRONMENTAL RESEARCH 2017; 152:280-293. [PMID: 27816865 DOI: 10.1016/j.envres.2016.10.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/26/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
Vaccines are prophylactics used as the first line of intervention to prevent, control and eradicate infectious diseases. Young children (before the age of six months) are the demographic group most exposed to recommended/mandatory vaccines preserved with Thimerosal and its metabolite ethylmercury (EtHg). Particularly in the less-developed countries, newborns, neonates, and young children are exposed to EtHg because it is still in several of their pediatric vaccines and mothers are often immunized with Thimerosal-containing vaccines (TCVs) during pregnancy. While the immunogenic component of the product has undergone more rigorous testing, Thimerosal, known to have neurotoxic effects even at low doses, has not been scrutinized for the limit of tolerance alone or in combination with adjuvant-Al during immaturity or developmental periods (pregnant women, newborns, infants, and young children). Scientific evidence has shown the potential hazards of Thimerosal in experiments that modeled vaccine-EtHg concentrations. Observational population studies have revealed uncertainties related to neurological effects. However, consistently, they showed a link of EtHg with risk of certain neurodevelopment disorders, such as tic disorder, while clearly revealing the benefits of removing Thimerosal from children's vaccines (associated with immunological reactions) in developed countries. So far, only rich countries have benefited from withdrawing the risk of exposing young children to EtHg. Regarding Thimerosal administered to the very young, we have sufficient studies that characterize a state of uncertainty: the collective evidence strongly suggests that Thimerosal exposure is associated with adverse neurodevelopmental outcomes. It is claimed that the continued use of Thimerosal in the less-developed countries is due to the cost to change to another preservative, such as 2-phenoxyethanol. However, the estimated cost increase per child in the first year of life is lower than estimated lifetime cost of caring for a child with a neurodevelopmental disorder, such tic disorder. The evidence indicates that Thimerosal-free vaccine options should be made available in developing countries.
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Affiliation(s)
- José G Dórea
- Professor Emeritus, Faculty of Health Sciences, Universidade de Brasilia, 70919-970 Brasilia, DF, Brazil.
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Abstract
CONTEXT Environmental mercury in the Amazon mostly originates from geochemical sources with some from artisanal gold mining (AGM). Geochemical-originated methylmercury (MeHg) reaches the aquatic food chain, ending up in fish. Inorganic Hg used in AGM is responsible for localised environmental contamination and occupational exposure of adults. In addition to this, iatrogenic ethylmercury (EtHg) derived from Thimerosal-containing vaccines (TCVs) exposes immunised infants. OBJECTIVE To understand Hg exposure in the Amazon in relation to environmental fish-MeHg exposure, occupational AGM activities and low-doses of TCV-EtHg. METHODS Medline and Thomson-Reuter Web of Science were searched to retrieve and select papers addressing Hg exposure and human health. RESULTS AND CONCLUSION Environmental-Hg studies addressed health effects associated with birth weight, infant linear growth and neurodevelopment, while, in adults, environmental and occupational studies addressed immune and neurological issues. No widespread clinical toxicity was reported due to fish-MeHg. However, mixed results associated with Hg exposure can be found. Reducing children's exposure to EtHg is possible using Thimerosal-free vaccines, but it is difficult to interfere with fish consumption without consequences to riverine subsistence populations. Policies to diminish Hg exposure should focus on controlling and/or curbing widespread use of Hg (in gold amalgamation) and promotion of Thimerosal-free vaccines for pregnant women and young children.
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Affiliation(s)
- José G Dórea
- a Universidade de Brasília , Brasília , DF , Brasil
| | - Rejane C Marques
- b Universidade Federal do Rio de Janeiro , Rio de Janeiro , RJ, Brasil
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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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Mercury Exposure in Healthy Korean Weaning-Age Infants: Association with Growth, Feeding and Fish Intake. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:14669-89. [PMID: 26593931 PMCID: PMC4661673 DOI: 10.3390/ijerph121114669] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/09/2015] [Accepted: 11/11/2015] [Indexed: 01/21/2023]
Abstract
Low-level mercury (Hg) exposure in infancy might be harmful to the physical growth as well as neurodevelopment of children. The aim of this study was to investigate postnatal Hg exposure and its relationship with anthropometry and dietary factors in late infancy. We recruited 252 healthy Korean infants between six and 24 months of age from an outpatient clinic during the 2009/2010 and 2013/2014 seasons. We measured the weight and height of the infants and collected dietary information using questionnaires. The Hg content of the hair and blood was assessed using inductively coupled plasma mass spectroscopy. The geometric mean Hg concentration in the hair and blood was 0.22 (95% confidence interval: 0.20–0.24) µg/g and 0.94 (n = 109, 95% confidence interval: 0.89–0.99) µg/L, respectively. The hair Hg concentration showed a good correlation with the blood Hg concentration (median hair-to-blood Hg ratio: 202.7, r = 0.462, p < 0.001) and was >1 µg/g in five infants. The hair Hg concentration showed significant correlations with weight gain after birth (Z-score of the weight for age—Z-score of the birthweight; r = −0.156, p = 0.015), the duration (months) of breastfeeding as the dominant method of feeding (r = 0.274, p < 0.001), and the duration of fish intake more than once per week (r = 0.138, p = 0.033). In an ordinal logistic regression analysis with categorical hair Hg content (quartiles), dietary factors, including breastfeeding as the dominant method of feeding in late infancy (cumulative odds ratio: 6.235, 95% confidence interval: 3.086–12.597, p < 0.001) and the monthly duration of fish intake more than once per week (cumulative odds ratio: 1.203, 95% confidence interval: 1.034–1.401; p = 0.017), were significantly associated with higher hair Hg content. Weight gain after birth was not, however, significantly associated with hair Hg content after adjustment for the duration of breastfeeding as the dominant method of feeding. Low-level Hg exposure through breastfeeding and fish intake as a complementary food did not directly affect anthropometry in this population. If prolonged breastfeeding is expected, however, the Hg exposure through fish intake may need to be monitored for both mothers and infants.
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Oh JH, Son MY, Choi MS, Kim S, Choi AY, Lee HA, Kim KS, Kim J, Song CW, Yoon S. Integrative analysis of genes and miRNA alterations in human embryonic stem cells-derived neural cells after exposure to silver nanoparticles. Toxicol Appl Pharmacol 2015; 299:8-23. [PMID: 26551752 DOI: 10.1016/j.taap.2015.11.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/31/2015] [Accepted: 11/05/2015] [Indexed: 12/31/2022]
Abstract
Given the rapid growth of engineered and customer products made of silver nanoparticles (Ag NPs), understanding their biological and toxicological effects on humans is critically important. The molecular developmental neurotoxic effects associated with exposure to Ag NPs were analyzed at the physiological and molecular levels, using an alternative cell model: human embryonic stem cell (hESC)-derived neural stem/progenitor cells (NPCs). In this study, the cytotoxic effects of Ag NPs (10-200μg/ml) were examined in these hESC-derived NPCs, which have a capacity for neurogenesis in vitro, at 6 and 24h. The results showed that Ag NPs evoked significant toxicity in hESC-derived NPCs at 24h in a dose-dependent manner. In addition, Ag NPs induced cell cycle arrest and apoptosis following a significant increase in oxidative stress in these cells. To further clarify the molecular mechanisms of the toxicological effects of Ag NPs at the transcriptional and post-transcriptional levels, the global expression profiles of genes and miRNAs were analyzed in hESC-derived NPCs after Ag NP exposure. The results showed that Ag NPs induced oxidative stress and dysfunctional neurogenesis at the molecular level in hESC-derived NPCs. Based on this hESC-derived neural cell model, these findings have increased our understanding of the molecular events underlying developmental neurotoxicity induced by Ag NPs in humans.
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Affiliation(s)
- Jung-Hwa Oh
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea; Department of human and environmental toxicology, University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Mi-Young Son
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahangno, Yuseong-gu, Daejeon 34141, Republic of Korea; Department of functional genomics, University of Science & Technology, 217 Gajungro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Mi-Sun Choi
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea
| | - Soojin Kim
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea
| | - A-Young Choi
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea
| | - Hyang-Ae Lee
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea; Department of human and environmental toxicology, University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Ki-Suk Kim
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea; Department of human and environmental toxicology, University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Janghwan Kim
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahangno, Yuseong-gu, Daejeon 34141, Republic of Korea; Department of functional genomics, University of Science & Technology, 217 Gajungro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Chang Woo Song
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea; Department of human and environmental toxicology, University of Science & Technology, Daejeon 34113, Republic of Korea.
| | - Seokjoo Yoon
- Korea Institute of Toxicology (KIT), Daejeon 34114, Republic of Korea; Department of human and environmental toxicology, University of Science & Technology, Daejeon 34113, Republic of Korea.
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Marques RC, Bernardi JVE, Abreu L, Dórea JG. Neurodevelopment outcomes in children exposed to organic mercury from multiple sources in a tin-ore mine environment in Brazil. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 68:432-441. [PMID: 25425160 DOI: 10.1007/s00244-014-0103-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 11/03/2014] [Indexed: 06/04/2023]
Abstract
Methylmercury (from fresh-water fish) and ethylmercury [from thimerosal-containing vaccines (TCVs)] are the most prevalent source of neurotoxic exposure during early life in families consuming fish and using these vaccines. But children living in Amazonian mining environments are exposed to additional toxic metals in waste materials. We studied mercury (Hg) exposure and neurodevelopment in 294 children (105 boys and 189 girls) from Bom Futuro (Rondonia, Brazil), the epicenter of a tin-ore open-pit mine. Hair-Hg (HHg) concentrations and total ethylmercury (from TCVs) were taken from infants and respective mothers during pregnancy. We used bivariate analysis to determine the effect of sex and linear mixed models to assess the association of prenatal and postnatal organic Hg exposures with children's Bayley Scales of Infant Development (BSID) as psychomotor developmental index and mental developmental index (MDI) at 6 and 24 months of age as well as milestones achievements (age of walking and age of talking). Significant differences between boys and girls were observed for both MDI score (p = 0.0073) and MDI score (p = 0.0288) at 6 months but not at 24 months. Regression analysis showed that only in boys was there a significant interaction between MDI score with family income (β = 0.288, p = 0.018) and with birth weight (β = -0.216, p = 0.036) at 6 months; at 24 months, however, only boys showed a significant association of both MDI score (β = -0.222, p = 0.045) and MDI score (β = -0.222, p = 0.045) with neonatal HHg. In boys, age of walking was associated with HHg (β = 0.188, p = 0.019) and breastfeeding (β = -0.282, p = 0.000), whereas for girls, age of walking was only associated with breastfeeding (β = -0.275, p = 0.001). In this mining environment, with only a weak association for prenatal Hg exposure, there was a significant sex difference in neurodevelopment, with boys showing more sensitivity related to BSID delays.
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Affiliation(s)
- Rejane C Marques
- Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 27930-560, Brazil,
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Geier DA, King PG, Hooker BS, Dórea JG, Kern JK, Sykes LK, Geier MR. Thimerosal: Clinical, epidemiologic and biochemical studies. Clin Chim Acta 2015; 444:212-20. [DOI: 10.1016/j.cca.2015.02.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 02/06/2015] [Accepted: 02/14/2015] [Indexed: 10/24/2022]
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Dórea JG. Exposure to mercury and aluminum in early life: developmental vulnerability as a modifying factor in neurologic and immunologic effects. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:1295-313. [PMID: 25625408 PMCID: PMC4344667 DOI: 10.3390/ijerph120201295] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/20/2015] [Indexed: 01/15/2023]
Abstract
Currently, ethylmercury (EtHg) and adjuvant-Al are the dominating interventional exposures encountered by fetuses, newborns, and infants due to immunization with Thimerosal-containing vaccines (TCVs). Despite their long use as active agents of medicines and fungicides, the safety levels of these substances have never been determined, either for animals or for adult humans—much less for fetuses, newborns, infants, and children. I reviewed the literature for papers reporting on outcomes associated with (a) multiple exposures and metabolism of EtHg and Al during early life; (b) physiological and metabolic characteristics of newborns, neonates, and infants relevant to xenobiotic exposure and effects; (c) neurobehavioral, immunological, and inflammatory reactions to Thimerosal and Al-adjuvants resulting from TCV exposure in infancy. Immunological and neurobehavioral effects of Thimerosal-EtHg and Al-adjuvants are not extraordinary; rather, these effects are easily detected in high and low income countries, with co-exposure to methylmercury (MeHg) or other neurotoxicants. Rigorous and replicable studies (in different animal species) have shown evidence of EtHg and Al toxicities. More research attention has been given to EtHg and findings have showed a solid link with neurotoxic effects in humans; however, the potential synergic effect of both toxic agents has not been properly studied. Therefore, early life exposure to both EtHg and Al deserves due consideration.
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Affiliation(s)
- José G Dórea
- Department of Nutrition, Faculty of Health Sciences, Universidade de Brasilia, 70919-970 DF Brasilia, Brazil.
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Early exposure to thimerosal-containing vaccines and children's cognitive development. A 9-year prospective birth cohort study in Poland. Eur J Pediatr 2015; 174:383-91. [PMID: 25185528 PMCID: PMC4334107 DOI: 10.1007/s00431-014-2412-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/18/2014] [Accepted: 08/25/2014] [Indexed: 11/12/2022]
Abstract
UNLABELLED The controversial topic of the early exposure to mercury is regarding ethylmercury, which is present in the thimerosal-containing vaccines (TCVs). The objective of this study was to determine the relationship between the early exposure to TCVs and cognitive development in children during the first 9 years of life. The cohort included 318 children vaccinated in an early period (neonatal and up to 6 months) against hepatitis B and diphtheria-tetanus-pertussis (DTP) using formulation with or without thimerosal. The children's development was assessed using the Fagan test (6th month of life), the Bayley Scales of Infant Development (BSID)-II (12th-36th month), the Raven test (5th, 8th year), and the Wechsler Intelligence Scale for Children (WISC-R) (6th, 7th, 9th year). Results were determined by multivariable linear and logistic regression, adjusted to potential confounders. Children exposed and not exposed to TCVs in the neonatal period had similar outcomes of cognitive-developmental tests; only the results of BSID-II at the 36th month and WISC-R at the 9th year were significantly higher for those exposed to TCVs. Developmental test results in children exposed to TCVs up to the 6th month of life also did not depend on thimerosal dose. CONCLUSION TCV administration in early infancy did not affect children's cognitive development.
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Dickerson AS, Pearson DA, Loveland KA, Rahbar MH, Filipek PA. Role of parental occupation in autism spectrum disorder diagnosis and severity. RESEARCH IN AUTISM SPECTRUM DISORDERS 2014; 8:997-1007. [PMID: 25024741 PMCID: PMC4093805 DOI: 10.1016/j.rasd.2014.05.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Aisha S. Dickerson
- Division of Epidemiology, Human Genetics and Environmental Sciences (EHGES), The University of Texas School of Public Health at Houston, Biostatistics/Epidemiology/Research Design Core, Center for Clinical and Translational Sciences (CCTS), The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Deborah A. Pearson
- Department of Psychiatry and Behavioral Sciences, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
| | - Katherine A. Loveland
- Department of Psychiatry and Behavioral Sciences, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
| | - Mohammad H. Rahbar
- Division of Epidemiology, Human Genetics and Environmental Sciences (EHGES), The University of Texas School of Public Health at Houston, Biostatistics/Epidemiology/Research Design Core, Center for Clinical and Translational Sciences (CCTS), The University of Texas Health Science Center at Houston Houston, Texas 77030, USA
| | - Pauline A. Filipek
- Department of Pediatrics, Children’s Learning Institute, and the Division of Child and Adolescent Neurology, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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The influence of changes in lifestyle and mercury exposure in riverine populations of the Madeira River (Amazon Basin) near a hydroelectric project. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:2437-55. [PMID: 24577285 PMCID: PMC3986985 DOI: 10.3390/ijerph110302437] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/28/2014] [Accepted: 01/30/2014] [Indexed: 11/17/2022]
Abstract
In the Amazon Basin, naturally occurring methylmercury bioaccumulates in fish, which is a key source of protein consumed by riverine populations. The hydroelectric power-plant project at Santo Antônio Falls allows us to compare the Hg exposure of riverine populations sparsely distributed on both sides of the Madeira river before the area is to be flooded. From 2009 to 2011, we concluded a population survey of the area (N = 2,008; representing circa 80% of community residents) that estimated fish consumption and mercury exposure of riverine populations with different degrees of lifestyle related to fish consumption. Fish samples from the Madeira river (N = 1,615) and 110 species were analyzed for Hg. Hair-Hg was significantly lower (p < 0.001) in less isolated communities near to the capital of Porto Velho (median 2.32 ppm) than in subsistence communities in the Cuniã Lake, 180 km from Porto Velho city (median 6.3 ppm). Fish Hg concentrations ranged from 0.01 to 6.06 µg/g, depending on fish size and feeding behavior. Currently available fish in the Madeira river show a wide variability in Hg concentrations. Despite cultural similarities, riparians showed hair-Hg distribution patterns that reflect changes in fish-eating habits driven by subsistence characteristics.
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Dórea JG, Marques RC, Abreu L. Milestone achievement and neurodevelopment of rural Amazonian toddlers (12 to 24 months) with different methylmercury and ethylmercury exposure. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2014; 77:1-13. [PMID: 24555642 DOI: 10.1080/15287394.2014.861335] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Neurological outcomes (Gesell development schedules [GDS]), age of walking, and age of talking were studied in 299 toddlers (12 to 24 mo) in relation to environmental (fish consumption and tin mining) exposure. Exposure to fish methylmercury (MeHg) consumption and iatrogenic ethylmercury (EtHg) in Thimerosal-containing vaccines (TCV) was quantified in toddlers from two rural villages (n = 91, Itapuã; n = 218, Bom Futuro) respectively populated by fishers and cassiterite miners. Median total hair Hg (HHg) concentrations of infants from Itapuã (3.5 μg/g) were significantly higher than those of infants from Bom Futuro (2.2 μg/g). Median EtHg exposure from TCV was also significantly higher in toddlers from Itapuã (137.5 μg) than in those from Bom Futuro (112.5 μg). There were no significant differences between groups for any of the Gesell schedules; however, there were proportionally more compromised toddlers (GDS < 70) in Itapuã than Bom Futuro. Median age of talking was not statistically different but median age of walking was significantly higher in Bom Futuro. In toddlers from both villages, of fishers and miners, HHg concentrations were significantly correlated with family fish consumption. A logistic regression model was applied to all infants after classification into two groups: above or below the median Gesell schedules. Overall, there was no distinctive pattern of neurodevelopment associated with either HHg or EtHg exposure; however, nutritional status was significantly associated with GDS. In conclusion, milestone achievement was delayed in toddlers from tin-ore mining communities. Despite significantly higher exposure to both forms of organic Hg (MeHg from maternal fish consumption, and EtHg from TCV) in toddlers from the fishing village, significant differences were seen only among the proportions of most severely affected toddlers (GDS < 70).
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Affiliation(s)
- José G Dórea
- a Department of Nutrition , Universidade de Brasília , Brasília , Brazil
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Vaccine adverse events reported during the first ten years (1998-2008) after introduction in the state of Rondonia, Brazil. BIOMED RESEARCH INTERNATIONAL 2013; 2013:853083. [PMID: 23509790 PMCID: PMC3586457 DOI: 10.1155/2013/853083] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 01/07/2013] [Accepted: 01/11/2013] [Indexed: 02/01/2023]
Abstract
Despite good safety records, vaccines given to young children can cause adverse events. We investigated the reported adverse events following immunization (AEFI) of vaccines given to children of less than seven years of age during the first ten years (1998 to 2008) in the state of Rondonia, Brazil. We worked with the events related to BCG (Bacillus Calmett-Guérin), HB (hepatitis B), DTwP/Hib (diphtheria-tetanus-pertussis+Hemophillus influenza b), DTP (diphtheria-tetanus-pertussis), MMR (mumps, measles, rubella), and YF (yellow fever) vaccines because they were part of the recommended scheme. The number of doses of vaccines given was 3,231,567 with an average of AEFI of 57.2/year during the studied period. DTwP/Hib was responsible for 298 (57.8%), DTP 114 (22.9%), HB 31 (6%), MMR 28 (5.4%), BCG 24 (4.7%), and YF 20 (3.9%) of the reported AEFI. The combination of the AEFI for DTwP/Hib vaccines showed the highest number of systemic (61.4%) and local events (33.8%). Young children (≤1-year old) were more susceptible to AEFI occurring in the 6 hours (54.2%) following vaccine uptake. This study suggests significant differences in reactogenicity of vaccines and that despite limitations of the AEFI Brazilian registry system we cannot ignore underreporting and should use the system to expand our understanding of adverse events and effects.
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Hassauer M, Kaiser E, Schneider K, Schuhmacher‐Wolz U. Collate the literature on toxicity data on mercury in experimental animals and humans (Part I – Data on organic mercury). ACTA ACUST UNITED AC 2012. [DOI: 10.2903/sp.efsa.2012.en-297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Hassauer
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Eva Kaiser
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Klaus Schneider
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
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Mrozek-Budzyn D, Majewska R, Kieltyka A, Augustyniak M. Neonatal exposure to Thimerosal from vaccines and child development in the first 3years of life. Neurotoxicol Teratol 2012; 34:592-7. [DOI: 10.1016/j.ntt.2012.10.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 10/03/2012] [Accepted: 10/05/2012] [Indexed: 11/27/2022]
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Dórea JG. Neurotoxic metal coexposures and neurodevelopment. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:A226; author reply A226-7. [PMID: 22659231 PMCID: PMC3385458 DOI: 10.1289/ehp.1205004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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Neurodevelopment of Amazonian infants: antenatal and postnatal exposure to methyl- and ethylmercury. J Biomed Biotechnol 2012; 2012:132876. [PMID: 22619491 PMCID: PMC3350976 DOI: 10.1155/2012/132876] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 02/04/2012] [Indexed: 11/29/2022] Open
Abstract
Neurodevelopment as Gesell development scores (GDSs) in relation to mercury exposure in infants (<6 months of age) of one urban center and two rural villages, respectively, of fisherman and cassiterite miners. Mean total hair-Hg (HHg) concentrations of infants from Itapuã (3.95 ± 1.8 ppm) were statistically (P = 0.0001) different from those of infants from Porto Velho (3.84 ± 5.5 ppm) and Bom Futuro (1.85 ± 0.9 ppm). Differences in vaccine coverage among these populations resulted in significantly higher (P = 0.0001) mean ethylmercury (EtHg) exposure in urban infants (150 μg) than in infants from either village (41.67 μg, Itapuã; 42.39 μg, Bom Futuro). There was an inverse significant (Spearman r = −0.2300; P = 0.0376) correlation between HHg and GDS for infants from Porto Velho, but not for the rural infants from Bom Futuro (Spearman r = 0.1336; P = 0.0862) and Itapuã (Spearman r = 0.1666; P = 0.5182). Logistic regression applied to variables above or below the median GDS showed that EtHg exposure (estimated probability = −0.0157; P = 0.0070) and breastfeeding score (estimated probability = −0.0066; P = 0.0536) score were significantly associated with GDS. Conclusion. In nurslings whose mothers are exposed to different levels of fish-MeHg (HHg), a higher score of neurological development at six months was negatively associated with exposure to additional TCV-EtHg. Results should be interpreted with caution because of unaccounted variables.
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Llop S, Guxens M, Murcia M, Lertxundi A, Ramon R, Riaño I, Rebagliato M, Ibarluzea J, Tardon A, Sunyer J, Ballester F. Prenatal exposure to mercury and infant neurodevelopment in a multicenter cohort in Spain: study of potential modifiers. Am J Epidemiol 2012; 175:451-65. [PMID: 22287639 DOI: 10.1093/aje/kwr328] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Vulnerability of the central nervous system to mercury is increased during early development. This study aimed to evaluate whether cord blood total mercury levels may have a negative effect on both mental and psychomotor development in a maternal-birth cohort from moderate-high fish consumption areas. Study subjects were 1,683 child participants in the INMA (Environment and Childhood) Project from 4 areas of Spain between 2003 and 2010. Cord blood total mercury levels were analyzed by atomic absorption spectrometry. Infant neurodevelopment was assessed around age 14 months by the Bayley Scales of Infant Development. Sociodemographic, lifestyle, and dietary information was obtained by questionnaire during pregnancy. The geometric mean of total mercury levels was 8.4 μg/L (95% confidence interval (CI): 8.1, 8.7). In multivariate analysis, a doubling in total mercury levels did not show an association with mental (β = 0.1, 95% CI: -0.68, 0.88) or psychomotor (β = -0.05, 95% CI: -0.79, 0.68) developmental delay; however, stratified findings by sex suggest a negative association between prenatal exposure to total mercury and psychomotor development among female infants (β = -1.09, 95% CI: -2.21, 0.03), although follow-up is required to confirm these results.
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Affiliation(s)
- Sabrina Llop
- Centre for Public Health Research, Valencia, Spain.
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Marques RC, Dórea JG, Leão RS, Dos Santos VG, Bueno L, Marques RC, Brandão KG, Palermo EFA, Guimarães JRD. Role of methylmercury exposure (from fish consumption) on growth and neurodevelopment of children under 5 years of age living in a transitioning (tin-mining) area of the western Amazon, Brazil. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2012; 62:341-350. [PMID: 21818617 DOI: 10.1007/s00244-011-9697-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 07/11/2011] [Indexed: 05/31/2023]
Abstract
Human occupation of the Amazon region has recently increased, bringing deforestation for agriculture and open-cast mining, activities that cause environmental degradation and pollution. Families of new settlers in mining areas might have a diet less dependent on abundant fish and their children might also be impacted by exposures to mining environments. Therefore, there is compounded interest in assessing young children's nutritional status and neurobehavioral development with regard to family fish consumption. Anthropometric (z-scores, WHO standards) and neurologic [Gesell developmental scores (GDS)] development in 688 preschool children (1-59 months of age) was studied. Overall, the prevalence of malnutrition [i.e., moderate stunting (≤2 H/A-Z), underweight (≤2 W/A-Z), and wasting (≤2 W/H-Z) were respectively 0.3% (n = 2), 1.6% (n = 11), and 2.5% (n = 17). Children's mean hair Hg (HHg) concentration was 2.56 μg/g (SD = 1.67); only 14% of children had HHg concentrations lower than 1 μg/g and 1.7% had ≥5 μg/g. The biomarker of fish consumption was weakly but positively correlated with GDS (Spearman r = 0.080; p = 0.035). In the bivariate model, attained W/H-Z scores were not significantly correlated with GDS. A moderate level of GDS deficits (70-84%) was seen in 20% of children. There was significant correlation between family fish consumption and children's hair Hg (HHg) (Spearman r = 0.1756; p < 0.0001) but no significant correlation between children's HHg and W/H-Z scores. However, the multivariate model showed that breastfeeding, a fish consumption biomarker (HHg), maternal education, and child's age were statistically significant associated with specific domains (language and personal-social) of the Gesell scale. In this mining environment, family fish-eating did not affect children's linear growth, but it showed a positive influence (along with maternal variables) on neurodevelopment. Health hazards attendant on a high prevalence of moderate neurodevelopment delays coexisting with exposure to multiple neurotoxic substances merits further investigation in poor environmental settings of tin-mining areas.
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Affiliation(s)
- Rejane C Marques
- Escola de Enfermagem Anna Nery, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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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: 816] [Impact Index Per Article: 62.8] [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.
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Affiliation(s)
- Susan P Walker
- Tropical Medicine Research Institute, The University of the West Indies, Kingston, Jamaica.
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Elabiad MT, Hook RE. Mercury content of blood transfusions for infants with extremely low birth weight. Pediatrics 2011; 128:331-4. [PMID: 21746718 DOI: 10.1542/peds.2010-3712] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES To assess whether blood transfusions for infants with birth weights of 1000 g or less are a source of mercury and whether any mercury delivered through the transfusion is above the currently set oral reference dose. PATIENTS AND METHODS We studied an observational cohort. Inclusion criteria included birth weight 1000 g or less and receipt of 1 or more packed red blood cell transfusions. Packed red blood cell units were tested prospectively for mercury levels. The quantity of transfused mercury was calculated on the basis of transfused volume and packed red blood cell mercury level. The resulting mercury level was compared with the reference dose as set by the Agency for Toxic Substances and Disease Registry, the World Health Organization, and the US Environmental Protection Agency. RESULTS Thirty-seven infants (birth weight: 736 ± 157 g; gestational age: 25.5 ± 1.5 weeks) met the inclusion criteria. A total of 325 transfusions from 49 packed red blood cell units were administered. Mercury was detected in 40 units. The average mercury level in a packed red blood cell unit was 1.9 ± 2.6 μg/L (median: 0.9 μg/L [interquartile range: 0.3-2.5]). None of the infants received any mercury above the reference dose set by the Agency for Toxic Substances and Disease Registry and the World Health Organization. Twelve infants received 1 transfusion, and 5 infants received 2 transfusions above the Environmental Protection Agency reference dose during their entire hospitalization. CONCLUSIONS Packed red blood cells are a source of mercury for infants. However, the amount delivered is low compared with currently set safety levels. The episodes in which mercury intake exceeded the reference dose were rare. However, without long-term follow-up, no conclusions can be made about the cognitive implications of these episodes.
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Affiliation(s)
- Mohamad T Elabiad
- Division of Neonatology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, USA.
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Dórea JG. Integrating Experimental (In Vitro and In Vivo) Neurotoxicity Studies of Low-dose Thimerosal Relevant to Vaccines. Neurochem Res 2011; 36:927-38. [DOI: 10.1007/s11064-011-0427-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2011] [Indexed: 12/01/2022]
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Dórea JG, Marques RC. Infants' exposure to aluminum from vaccines and breast milk during the first 6 months. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2010; 20:598-601. [PMID: 20010978 DOI: 10.1038/jes.2009.64] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 11/04/2009] [Indexed: 05/28/2023]
Abstract
The success of vaccination programs in reducing and eliminating infectious diseases has contributed to an ever-increasing number of vaccines given at earlier ages (newborns and infants). Exposure to low levels of environmental toxic substances (including metals) at an early age raises plausible concerns over increasingly lower neuro-cognitive rates. Current immunization schedules with vaccines containing aluminum (as adjuvant) are given to infants, but thimerosal (as preservative) is found mostly in vaccines used in non-industrialized countries. Exclusively, breastfed infants (in Brazil) receiving a full recommended schedule of immunizations showed an exceedingly high exposure of Al (225 to 1750 μg per dose) when compared with estimated levels absorbed from breast milk (2.0 μg). This study does not dispute the safety of vaccines but reinforces the need to study long-term effects of early exposure to neuro-toxic substances on the developing brain. Pragmatic vaccine safety needs to embrace conventional toxicology, addressing especial characteristics of unborn fetuses, neonates and infants exposed to low levels of aluminum, and ethylmercury traditionally considered innocuous to the central nervous system.
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Affiliation(s)
- José G Dórea
- Department of Nutrition, Universidade de Brasília, Brasília, DF, Brazil.
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Dórea JG. Making sense of epidemiological studies of young children exposed to thimerosal in vaccines. Clin Chim Acta 2010; 411:1580-6. [DOI: 10.1016/j.cca.2010.07.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 07/08/2010] [Accepted: 07/10/2010] [Indexed: 12/16/2022]
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Benefice E, Luna-Monrroy S, Lopez-Rodriguez R. Fishing activity, health characteristics and mercury exposure of Amerindian women living alongside the Beni River (Amazonian Bolivia). Int J Hyg Environ Health 2010; 213:458-64. [DOI: 10.1016/j.ijheh.2010.08.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 08/18/2010] [Accepted: 08/19/2010] [Indexed: 11/28/2022]
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Hydroelectric reservoir inundation (Rio Madeira Basin, Amazon) and changes in traditional lifestyle: impact on growth and neurodevelopment of pre-school children. Public Health Nutr 2010; 14:661-9. [DOI: 10.1017/s136898001000248x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractObjectiveTo assess the dependence on fish consumption of families and its impact on nutritional status and neurodevelopment of pre-school children.DesignCross-sectional study that measured children’s hair mercury (HHg) as an indicator of family fish consumption, growth (anthropometricZ-scores, WHO standards) and neurological (Gesell developmental scores (GDS)) development.SettingTraditional living conditions among families residing in the area adjacent to the Samuel Dam (Western Amazon) hydroelectric reservoir.SubjectsTwo hundred and forty-nine pre-school children (1–59 months of age) from families transitioning from the traditional Amazonian lifestyle.ResultsFamily fish consumption was significantly correlated with children’s HHg concentration (Spearman’sr= 0·246,P< 0·0001); however, HHg had no significant association with growth (Z-scores). Overall, the prevalence of severe malnutrition, i.e. stunting (height-for-ageZ-score (HAZ) ≤ −3), underweight (weight-for-ageZ-score (WAZ) ≤ −3) and wasting (weight-for-heightZ-score (WHZ) ≤ −3) was 5·2 % (n13), 0 % and 0·8 % (n2), respectively. The prevalence of moderate stunting (HAZ ≥ −3 to ≤ −2), underweight (WAZ ≥ −3 to ≤ −2) and wasting (WHZ ≥ −3 to ≤ −2) was 8·8 % (n22), 2·4 % (n6) and 4·8 % (n12), respectively. Although 76 % of the children showed adequate GDS (>85), multiple regression analysis showed that fish consumption (as HHg) had no impact on GDS, but that some variables did interact significantly with specific domains (motor and language development).ConclusionsThe study showed that the families’ shift in fish consumption had no negative impact on the growth of young children and that ensuing methylmercury exposure has not been a noticeable neurodevelopmental hindrance.
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Research into mercury exposure and health education in subsistence fish-eating communities of the Amazon basin: potential effects on public health policy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2010; 7:3467-77. [PMID: 20948936 PMCID: PMC2954557 DOI: 10.3390/ijerph7093467] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 08/30/2010] [Accepted: 09/10/2010] [Indexed: 01/17/2023]
Abstract
The neurotoxic effects of fish-methylmercury (meHg) consumed regularly are considered hazardous to fetuses and newborn infants; as a result fish consumption advisories are an important asset to control meHg exposure in affluent societies. These concerns are now part of health promotion programs for Amazon subsistence villagers. While urban dwellers in affluent societies can choose an alternative nutritious diet, traditional and subsistence communities are caught up in controversial issues and lifestyle changes with unintended health consequences. Traditional fish-eating populations of industrialized and non-industrialized regions may be exposed to different neurotoxic substances: man-made pollutants and environmentally occurring meHg. Additionally, in non-industrialized countries, pregnant women and infants are still being immunized with thimerosal-containing vaccines (TCVs) which degrade to ethylmercury (etHg). Therefore, the complexity involving fish-meHg associated with wild-fish choices and Hg exposure derived from TCVs is difficult to disentangle and evaluate: are villagers able to distinguish exposure to differently hazardous chemical forms of Hg (inorganic, fish-meHg, and injected etHg)? Is it possible that instead of helping to prevent a plausible (unperceived) fish-meHg associated neurocognitive delay we may inadvertently arouse panic surrounding Hg exposure and disrupt subsistence fish-eating habits (necessary for survival) and life-saving vaccination programs (required by public health authorities)? These questions characterize the incompleteness of information related on the various chemical forms of Hg exposure and the need to convey messages that do not disrupt nutritional balance and disease prevention policies directed at Amazonian subsistence communities.
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Spulber S, Rantamäki T, Nikkilä O, Castrén E, Weihe P, Grandjean P, Ceccatelli S. Effects of maternal smoking and exposure to methylmercury on brain-derived neurotrophic factor concentrations in umbilical cord serum. Toxicol Sci 2010; 117:263-9. [PMID: 20631062 DOI: 10.1093/toxsci/kfq216] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin essential for neuronal survival and differentiation. We examined the concentration of BDNF in cord serum from newborns exposed to methylmercury (MeHg) and polychlorinated biphenyls (PCB) in utero by maternal consumption of whale meat. The cohort consisted of 395 singleton births (206 boys and 189 girls), gestational age ranging from 38 to 42 weeks. Serum BDNF was measured by sandwich ELISA. Maternal smoking habits and other relevant factors were obtained by interviewing the mothers. The exposure to MeHg was estimated from Hg concentrations in cord blood, whereas exposure to PCB was estimated based on maternal serum concentrations. Only MeHg exposure affected the serum BDNF, which decreased in a concentration-dependent manner in girls born to nonsmoking mothers. Maternal smoking significantly increased BNDF in girls but not in boys. For further statistical analyses, we used the serum BDNF concentration as a continuous outcome variable in supervised regression models. Serum BDNF concentration increased with gestational age, increased by maternal smoking, decreased slightly with MeHg exposure, and maternal smoking enhanced the decrease in serum BDNF induced by MeHg exposure. Cord blood BDNF has been reported to increase in association with perinatal brain injuries and has been proposed as a possible predictive marker of neurodevelopmental outcomes. The negative effect that MeHg seems to exert on cord blood BDNF concentration could endanger compensatory responses to an adverse impact and therefore deserves attention.
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Affiliation(s)
- Stefan Spulber
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
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Marques RC, Dórea JG, Bernardi JVE. Thimerosal exposure (from tetanus-diphtheria vaccine) during pregnancy and neurodevelopment of breastfed infants at 6 months. Acta Paediatr 2010; 99:934-9. [PMID: 20003103 DOI: 10.1111/j.1651-2227.2009.01641.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
AIM We studied the effect on neurodevelopment of infants who are exposed to thimerosal in tetanus-diphtheria (Td) vaccines during pregnancy. METHODS We compared Gesell Developmental Schedules (GDS) of exclusive breastfed infants at 6 months born to mothers who received Td (1 to 3 doses) against those who were born to mothers who did not take such vaccines. RESULTS Compared with the group of infants not exposed to ethylmercury in utero, the infants of exposed mothers showed no significant difference in neurodevelopment delays. Although there was a significant correlation between hair-Hg of mothers and hair-Hg of neonates (Spearman r = 0.353; p = 0.0011), there was no significant correlation between the level of in utero exposure to ethylmercury in Td vaccines and neonate's hair-Hg concentrations (Spearman r = 0.060; p = 0.5922). However, regression analysis showed that GDS at 6 months was significantly associated with total mercury concentration of neonate's hair but was not sensitive to the number of vaccines taken by the mother. CONCLUSION Early neurodevelopment of exclusively breastfed infants is sensitive to in utero exposure to mercury, but maternal thimerosal exposure in tetanus-diphtheria vaccines per se cannot portend clinical neurodevelopment delays measured by GDS at 6 months.
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Affiliation(s)
- R C Marques
- Fundação Universidade Federal de Rondônia. Porto Velho, RO, Brasil
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Dórea JG. More on low-level non-occupational mercury exposure and health concerns. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:2008-2010. [PMID: 20149921 DOI: 10.1016/j.scitotenv.2010.01.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Accepted: 01/22/2010] [Indexed: 05/28/2023]
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Abstract
AIM This article explores the role of breastfeeding in different aspects of vaccination in the first 6 months when infants are still developing: (1) pain management; (2) immunomodulation of infants' vaccine responses; (3) metabolism of thimerosal. METHODS Major databases were searched for studies that addressed outcomes of related issues. RESULTS Studies reveal that breastfeeding can: (1) help mothers and infants to cope with the stressful situations that accompany parenteral vaccines; (2) improve response to vaccines in the still maturing immunologic and enterohepatic systems of infants; (3) influence physiologic parameters that can change metabolism of ethylmercury derived from some vaccines. CONCLUSION Health promotion that supports vaccinations should also emphasize early initiation and maintenance of exclusive breastfeeding up until 6 months for maximum protection of the infants with a possible beneficial effect on the vaccine response. Paediatric professionals should inform mothers of the proven benefits of breastfeeding and its importance in complementing vaccination and lowering stress and the risk of untoward reactions on susceptible infants.
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Affiliation(s)
- Josè G Dòrea
- Department of Nutrition, Universidade de Brasília, 70919-970 Brasília, DF, Brazil.
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