title: Assessment of mercury exposure among small-scale gold miners using mercury stable isotopes.
abstract: Total mercury (Hg) concentrations in hair and urine are often used as biomarkers of exposure to fish-derived methylmercury (MeHg) and gaseous elemental Hg, respectively. We used Hg stable isotopes to assess the validity of these biomarkers among small-scale gold mining populations in Ghana and Indonesia. Urine from Ghanaian miners displayed similar Δ(199)Hg values to Hg derived from ore deposits (mean urine Δ(199)Hg=0.01‰, n=6). This suggests that urine total Hg concentrations accurately reflect exposure to inorganic Hg among this population. Hair samples from Ghanaian miners displayed low positive Δ(199)Hg values (0.23-0.55‰, n=6) and low percentages of total Hg as MeHg (7.6-29%, n=7). These data suggest that the majority of the Hg in these miners' hair samples is exogenously adsorbed inorganic Hg and not fish-derived MeHg. Hair samples from Indonesian gold miners who eat fish daily displayed a wider range of positive Δ(199)Hg values (0.21-1.32‰, n=5) and percentages of total Hg as MeHg (32-72%, n=4). This suggests that total Hg in the hair samples from Indonesian gold miners is likely a mixture of ingested fish MeHg and exogenously adsorbed inorganic Hg. Based on data from both populations, we suggest that total Hg concentrations in hair samples from small-scale gold miners likely overestimate exposure to MeHg from fish consumption.
authors.affiliation: University of Michigan, Department of Earth and Environmental Sciences, 1100 North University Avenue, Ann Arbor, MI 48109, United States. Electronic address: lsaylors@umich.edu.
authors.forename: Laura S
authors.initials: LS
authors.lastname: Sherman
authors.affiliation: University of Michigan, Department of Earth and Environmental Sciences, 1100 North University Avenue, Ann Arbor, MI 48109, United States.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Blum
authors.affiliation: McGill University, Faculty of Agricultural and Environmental Sciences, 21,111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, Canada H9X3V9.
authors.forename: Niladri
authors.initials: N
authors.lastname: Basu
authors.affiliation: University of Michigan, Department of Environmental Health Sciences, 1415 Washington Heights, Ann Arbor, MI 48109, United States.
authors.forename: Mozhgon
authors.initials: M
authors.lastname: Rajaee
authors.affiliation: Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038, United States.
authors.forename: David C
authors.initials: DC
authors.lastname: Evers
authors.affiliation: Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038, United States.
authors.forename: David G
authors.initials: DG
authors.lastname: Buck
authors.affiliation: Arnika Association, Chlumova 17, Prague 3, Czech Republic.
authors.forename: Jindrich
authors.initials: J
authors.lastname: Petrlik
authors.affiliation: IPEN, Box 7256, SE-402 35 Gothenburg, Sweden.
authors.forename: Joseph
authors.initials: J
authors.lastname: DiGangi
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism / Q000652:urine; D004784:Environmental Monitoring; D005260:Female; D005399:Fishes / Q000378:metabolism*; D005869:Ghana; D006197:Hair / Q000737:chemistry; D006801:Humans; D007214:Indonesia; D008297:Male; D013058:Mass Spectrometry; D008628:Mercury / Q000032:analysis / Q000378:metabolism* / Q000652:urine; D008629:Mercury Isotopes / Q000032:analysis / Q000378:metabolism / Q000652:urine; D008767:Methylmercury Compounds / Q000032:analysis / Q000378:metabolism* / Q000652:urine; D008875:Middle Aged; D008906:Mining; D016273:Occupational Exposure; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism* / Q000652:urine; D055815:Young Adult
chemical_list: D015415:Biomarkers; D008629:Mercury Isotopes; D008767:Methylmercury Compounds; D012989:Soil Pollutants; D008628:Mercury
keywords: Biomarkers; Mercury isotopes; Methylmercury; Small-scale gold mining