title: A longitudinal study of mercury exposure associated with consumption of freshwater fish from a reservoir in rural south central USA.
abstract: Methylmercury (MeHg) exposure through fish consumption is a worldwide health concern. Saltwater fish account for most dietary MeHg exposure in the general U.S. population, but less is known about seasonal variations in MeHg exposure and fish consumption among millions of freshwater anglers. This longitudinal study examined associations between MeHg exposure and fish consumption in a rural, low-income population relying on a freshwater reservoir (Oklahoma, USA) for recreational and subsistence fishing. We interviewed 151 participants, primarily anglers and their families, seasonally for one year using 90-day recall food frequency questionnaires to assess general and species-specific fish consumption, and tested hair biomarker samples for total mercury (THg hair). Mean THg hair was 0.27 μg/g (n=595, range: 0.0044-3.1 μg/g), with 4% of participants above U.S. EPA's guideline for women of childbearing age and children. Mean fish consumption was 58 g/d (95% CI: 49-67 g/d), within the range previously reported for recreational freshwater anglers and above the national average. Unlike the general U.S. population, freshwater species contributed the majority of fish consumption (69%) and dietary Hg exposure (60%) among participants, despite relatively low THg in local fish. THg hair increased with fish consumption, age, and education, and was higher among male participants and the lowest in winter. Our results suggest that future studies of anglers should consider seasonality in fish consumption and MeHg exposure and include household members who share their catch. Efforts to evaluate benefits of reducing Hg emissions should consider dietary patterns among consumers of fish from local freshwater bodies.
authors.affiliation: Harvard School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA 02215, USA.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Local Environmental Action Demanded (L.E.A.D.) Agency, 223 A Street SE, Miami, OK 74354, USA.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Jim
authors.affiliation: Local Environmental Action Demanded (L.E.A.D.) Agency, 223 A Street SE, Miami, OK 74354, USA.
authors.forename: Earl L
authors.initials: EL
authors.lastname: Hatley
authors.affiliation: Harvard School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA 02215, USA.
authors.forename: Ann S N
authors.initials: AS
authors.lastname: Backus
authors.affiliation: Harvard School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA 02215, USA.
authors.forename: James P
authors.initials: JP
authors.lastname: Shine
authors.affiliation: Harvard School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA 02215, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Spengler
authors.affiliation: Harvard School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA 02215, USA. Electronic address: schaider@silentspring.org.
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Schaider
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D005399:Fishes; D005502:Food; D006197:Hair / Q000737:chemistry; D006801:Humans; D008137:Longitudinal Studies; D008628:Mercury / Q000032:analysis / Q000633:toxicity*; D012621:Seasons; D014481:United States
chemical_list: D008628:Mercury
keywords: Exposure; Fish consumption; Fishing; Mercury; Season