title: Mercury in fish and adverse reproductive outcomes: results from South Carolina.
abstract: BACKGROUND
  Mercury is a metal with widespread distribution in aquatic ecosystems and significant neurodevelopmental toxicity in humans. Fish biomonitoring for total mercury has been conducted in South Carolina (SC) since 1976, and consumption advisories have been posted for many SC waterways. However, there is limited information on the potential reproductive impacts of mercury due to recreational or subsistence fish consumption.
  
  
  METHODS
  To address this issue, geocoded residential locations for live births from the Vital Statistics Registry (1995-2005, N = 362,625) were linked with spatially interpolated total mercury concentrations in fish to estimate potential mercury exposure from consumption of locally caught fish. Generalized estimating equations were used to test the hypothesis that risk of low birth weight (LBW, <2,500 grams) or preterm birth (PTB, < 37 weeks clinical gestation) was greater among women living in areas with elevated total mercury in fish, after adjustment for confounding. Separate analyses estimated term LBW and PTB risks using residential proximity to rivers with fish consumption advisories to characterize exposure.
  
  
  RESULTS
  Term LBW was more likely among women residing in areas in the upper quartile of predicted total mercury in fish (odds ratio [OR] = 1.04; 95% confidence interval [CI]: 1.00-1.09) or within 8 kilometers of a river with a 'do not eat' fish advisory (1.05; 1.00-1.11) compared to the lowest quartile, or rivers without fish consumption restrictions, respectively. When stratified by race, risks for term LBW or PTB were 10-18% more likely among African-American (AA) mothers living in areas with the highest total fish mercury concentrations.
  
  
  CONCLUSIONS
  To our knowledge, this is the first study to examine the relationship between fish total mercury concentrations and adverse reproductive outcomes in a large population-based sample that included AA women. The ecologic nature of exposure assessment in this study precludes causal inference. However, the results suggest a need for more detailed investigations to characterize patterns of local fish consumption and potential dose-response relationships between mercury exposure and adverse reproductive outcomes, particularly among AA mothers.
authors.affiliation: Department of Epidemiology & Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA. burch@mailbox.sc.edu.
authors.forename: James B
authors.initials: JB
authors.lastname: Burch
authors.forename: Sara
authors.initials: S
authors.lastname: Wagner Robb
authors.forename: Robin
authors.initials: R
authors.lastname: Puett
authors.forename: Bo
authors.initials: B
authors.lastname: Cai
authors.forename: Rebecca
authors.initials: R
authors.lastname: Wilkerson
authors.forename: Wilfried
authors.initials: W
authors.lastname: Karmaus
authors.forename: John
authors.initials: J
authors.lastname: Vena
authors.forename: Erik
authors.initials: E
authors.lastname: Svendsen
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D005399:Fishes; D006801:Humans; D007230:Infant, Low Birth Weight / Q000502:physiology; D007234:Infant, Premature / Q000502:physiology; D018811:Maternal Exposure / Q000009:adverse effects*; D008628:Mercury / Q000633:toxicity*; D008875:Middle Aged; D011247:Pregnancy; D013022:South Carolina / Q000453:epidemiology; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D055815:Young Adult
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury