title: Recent Epidemiological Studies on Methylmercury, Mercury and Selenium.
abstract: More than sixty years has passed since the outbreak of Minamata disease, and high-level methylmercury contaminations now seem nonexistent in Japan. However, mercury has been continuously discharged from natural sources and industrial activities, and the health effects on children susceptible to methylmercury exposure at low levels, in addition to mercury contamination from mercury or gold mining areas in developing countries, become a worldwide concern. In this article, we provide a recent overview of epidemiological studies regarding methylmercury and mercury. The following findings were obtained. (1) Many papers on exposure assessment of methylmercury/mercury have been published since the Minamata Convention on Mercury was adopted in 2013. (2) The most crucial problem is child developmental neurotoxicity resulting from prenatal exposure to methylmercury, but its precise assessment seems to be difficult because most of such effects are neither severe nor specific. (3) Several problems raised in birth cohort studies (e.g., whether IQ deficits due to prenatal methylmercury exposure remain when the children become adults, or whether the postnatal exposure at low levels also causes such adverse effects in children) remain unsolved. (4) Concurrent exposure models of methylmercury, lead, polychlorinated biphenyls, aresenic, and organochlorine pesticides, as well as possible antagonists such as polyunsaturated fatty acids and selenium, should be considered in the study design because the exposure levels of methylmercury are extremely low in developed countries. (5) Further animal experiments and molecular biological studies, in addition to human studies, are required to clarify the mechanism of methylmercury toxicity.
authors.affiliation: Department of Hygiene and Public Health, Kyorin University School of Medicine.
authors.forename: Kanae
authors.initials: K
authors.lastname: Karita
authors.forename: Mineshi
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshida
authors.forename: Nozomi
authors.initials: N
authors.lastname: Tatsuta
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Nakai
authors.forename: Miyuki
authors.initials: M
authors.lastname: Iwai-Shimada
authors.forename: Toyoto
authors.initials: T
authors.lastname: Iwata
authors.forename: Eri
authors.initials: E
authors.lastname: Maeda
authors.forename: Kozue
authors.initials: K
authors.lastname: Yaginuma-Sakurai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Satoh
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Murata
mesh_terms: D015331:Cohort Studies; D002658:Developmental Disabilities / Q000139:chemically induced / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D015340:Epidemiologic Research Design; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D017669:Mercury Compounds / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000633:toxicity*; D008906:Mining; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000453:epidemiology; D018036:Selenium Compounds / Q000633:toxicity*
chemical_list: D017669:Mercury Compounds; D008767:Methylmercury Compounds; D018036:Selenium Compounds