title: The Seychelles study of fetal methylmercury exposure and child development: introduction.
abstract: Studies of outbreaks of methylmercury poisoning in Japan and Iraq from consumption of methylmercury (MeHg)-contaminated fish or bread proved that brain was the target organ, the toxic effects were dose-related, and the fetal brain was especially susceptible. Previous population studies suggested that a 5% risk of minimal fetal effect may be associated with a maternal hair mercury concentration during pregnancy of 10-20 ppm (mu g/g), a level that can be readily achieved by frequent consumers of fish. However, these studies had limitations, and as a result no definite conclusion concerning the lowest effect level could be reached and the question of a possible hazard to public health remained unanswered. There was a clear need for a more definitive study that would be prospective, involve a large enough cohort for risk analysis and adhere to accepted epidemiological principles. An appropriate site for such a study is the Republic of Seychelles, a location that afforded successful collaboration between the Seychelles Ministry of Health and faculty of the University of Rochester. A pilot study of 804 infant-mother pairs was followed by a main study of 779 mother-infant pairs. In the pilot study children were examined once between 5 and 109 weeks of age; in the main study they are being evaluated longitudinally starting at 6 1/2 months of age. This paper introduces both the pilot and main studies, describes their design, and summarizes the findings through 6 1/2 months of age. When the Seychelles study is completed, the analyses will provide a database for those nations that choose to regulate their citizens' fish consumption and/or provide dietary education.
authors.affiliation: Department of Neurology, University of Rochester School of Medicine, New York 14642, USA.
authors.forename: D O
authors.initials: DO
authors.lastname: Marsh
authors.forename: T W
authors.initials: TW
authors.lastname: Clarkson
authors.forename: G J
authors.initials: GJ
authors.lastname: Myers
authors.forename: P W
authors.initials: PW
authors.lastname: Davidson
authors.forename: C
authors.initials: C
authors.lastname: Cox
authors.forename: E
authors.initials: E
authors.lastname: Cernichiari
authors.forename: M A
authors.initials: MA
authors.lastname: Tanner
authors.forename: W
authors.initials: W
authors.lastname: Lednar
authors.forename: C
authors.initials: C
authors.lastname: Shamlaye
authors.forename: O
authors.initials: O
authors.lastname: Choisy
mesh_terms: D002648:Child; D002657:Child Development / Q000187:drug effects*; D004781:Environmental Exposure; D004782:Environmental Health; D005260:Female; D006801:Humans; D008431:Maternal-Fetal Exchange; D008628:Mercury / Q000633:toxicity*; D011247:Pregnancy; D012750:Seychelles
chemical_list: D008628:Mercury