title: Fetal methylmercury exposure as measured by cord blood mercury concentrations in a mother-infant cohort in Hong Kong.
abstract: This study was designed to examine newborn infants in Hong Kong prenatally exposed to levels of methylmercury considered to increase risk of neurotoxic effects and to examine subject characteristics that modify the degree of prenatal mercury exposure. Mercury concentrations in 1057 sets of maternal and cord blood samples and 96 randomly selected maternal hair samples were measured. Subject characteristics were measured or collected by questionnaire. Of the 1057 cord blood samples collected only 21.6% had mercury concentrations less than 29 nmol/L (5.8 micro g/L). Median maternal hair mercury concentration was 1.7 ppm. The geometric mean cord to maternal blood mercury ratio was 1.79 to 1. Increasing maternal fish consumption and maternal age were found to be associated with increased cord blood mercury concentrations. Marine fish consumption increased cord blood mercury concentrations more than freshwater fish (5.09%/kg vs 2.86%/kg). Female babies, maternal alcohol consumption and increasing maternal height were associated with decreased cord blood mercury concentrations. Pregnant women in Hong Kong consume large amounts of fish and as a result, most of their offspring have been prenatally exposed to moderately high levels of mercury. In this population, pregnant women should choose freshwater over marine fish and limit fish consumption.
authors.affiliation: Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong. taifaifok@cuhk.edu.hk
authors.forename: Tai F
authors.initials: TF
authors.lastname: Fok
authors.forename: Hugh S
authors.initials: HS
authors.lastname: Lam
authors.forename: Pak C
authors.initials: PC
authors.lastname: Ng
authors.forename: Alexander S K
authors.initials: AS
authors.lastname: Yip
authors.forename: Ngai C
authors.initials: NC
authors.lastname: Sin
authors.forename: Iris H S
authors.initials: IH
authors.lastname: Chan
authors.forename: Goldie J S
authors.initials: GJ
authors.lastname: Gu
authors.forename: Hung K
authors.initials: HK
authors.lastname: So
authors.forename: Eric M C
authors.initials: EM
authors.lastname: Wong
authors.forename: Christopher W K
authors.initials: CW
authors.lastname: Lam
mesh_terms: D000818:Animals; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005399:Fishes; D005506:Food Contamination; D006723:Hong Kong; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D008431:Maternal-Fetal Exchange; D008628:Mercury / Q000097:blood*; D008767:Methylmercury Compounds / Q000633:toxicity; D011247:Pregnancy; D011897:Random Allocation; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury