title: Country-specific estimates of the incidence of intellectual disability associated with prenatal exposure to methylmercury.
abstract: This paper describes country-specific estimates of the incidence of intellectual disability in children associated with prenatal exposure to methylmercury. A systematic review was undertaken to identify country-specific data on hair mercury concentrations in women of reproductive age. A variety of approaches were used to estimate biomarker concentrations for countries lacking such data. A dose-effect relationship derived on the basis of the data from three large prospective studies relating prenatal methylmercury exposure to IQ in children was used to estimate the country-specific incidences of mild, moderate, severe, and profound intellectual disability in children as a result of prenatal methylmercury exposure. The incidence of methylmercury-associated mild intellectual disability (IQ scores 50-70) varied nearly 40-fold across countries, with the greatest incidences generally in countries that are islands or that are coastal. Countries with high birth rates and greater consumption of foods that contribute most to methylmercury intake in humans (seafood, rice) can be expected to make the largest contributions to the worldwide burden of disease associated with methylmercury. The assumptions and limitations of the estimates are discussed.
authors.affiliation: Departments of Neurology and Psychiatry, Harvard Medical School, United States; Department of Environmental Health, Harvard School of Public Health, United States; Boston Children's Hospital, United States. Electronic address: david.bellinger@childrens.harvard.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Bellinger
authors.affiliation: Gibb Epidemiology Consulting LLC, United States; George Washington University Milken Institute School of Public Health, United States.
authors.forename: Keri
authors.initials: K
authors.lastname: O'Leary
authors.affiliation: George Washington University Milken Institute School of Public Health, United States.
authors.forename: Holly
authors.initials: H
authors.lastname: Rainis
authors.affiliation: Gibb Epidemiology Consulting LLC, United States.
authors.forename: Herman J
authors.initials: HJ
authors.lastname: Gibb
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D005506:Food Contamination; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000139:chemically induced / Q000453:epidemiology*; D008767:Methylmercury Compounds / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000453:epidemiology*; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D008767:Methylmercury Compounds
keywords: Children; Global; Intellectual disability; Methylmercury; Prenatal exposure