title: Differences in prenatal exposure to mercury in South African communities residing along the Indian Ocean.
abstract: Mercury is a persistent environmental pollutant that has the potential to adversely affect human health, particularly, foetal neurodevelopment. The purpose of the study was to investigate prenatal mercury (Hg) exposure in the population in three sites along the South Africa coast. Study subjects included women (n=350) who were admitted for delivery at the local hospitals. Maternal and cord blood samples were collected to measure total mercury and each participant was required to answer a questionnaire. The 90th percentile of mercury levels in maternal and cord blood of the total population was 1.15 μg/l and 1.67 μg/l, respectively. Site 1 (Manguzi) participants had the highest maternal geometric mean (GM) values of 0.93 μg/l, which was significantly different from Site 2 (Port Shepstone) (0.49 μg/l) and Site 3 (Empangeni) (0.56 μg/l) (ANOVA test, p<0.001). Umbilical cord blood GM Hg level for Site 1 (1.45 μg/l) was more than double the GM Hg level in Site 2 (0.70 μg/l) and Site 3 (0.73 μg/l). Univariate analysis indicated that the following maternal characteristics were positive predictors for elevated umbilical cord Hg levels: maternal blood Hg levels, living with a partner, residing in Site 1, living in informal housing, using wood and gas for cooking, borehole water as a drinking source, and a member of the household being involved in fishing. Maternal dietary predictors of elevated Hg levels in umbilical cord blood included consuming fresh fish, tinned fish, fruit or dairy products, daily. This study provides baseline data and reveals that 2% of the study population were above the EPA's reference value (5.8 μg/l) suggesting low level exposure to mercury in pregnant women and the developing foetus in South Africa. Further research is required to explore the sources of elevated Hg levels in Site 1.
authors.affiliation: Institute of Community Medicine, University of Tromsø, Tromsø, Norway; National Health Laboratory Service (NHLS), National Institute for Occupational Health (NIOH), Johannesburg, South Africa. Electronic address: Kalavati.Channa@nioh.nhls.ac.za.
authors.forename: Kalavati
authors.initials: K
authors.lastname: Channa
authors.forename: Jon Ø
authors.initials: JØ
authors.lastname: Odland
authors.forename: Tahira
authors.initials: T
authors.lastname: Kootbodien
authors.forename: Penny
authors.initials: P
authors.lastname: Theodorou
authors.forename: Inakshi
authors.initials: I
authors.lastname: Naik
authors.forename: Torkjel M
authors.initials: TM
authors.lastname: Sandanger
authors.forename: Halina B
authors.initials: HB
authors.lastname: Röllin
mesh_terms: D000293:Adolescent; D000328:Adult; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D019156:Indian Ocean / Q000453:epidemiology; D017669:Mercury Compounds / Q000097:blood; D008630:Mercury Poisoning / Q000453:epidemiology*; D008875:Middle Aged; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012307:Risk Factors; D018036:Selenium Compounds / Q000097:blood; D012959:Socioeconomic Factors; D013019:South Africa / Q000453:epidemiology; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D017669:Mercury Compounds; D018036:Selenium Compounds
keywords: Africa; Cord-blood; Fish; Maternal; Mercury; Pregnant