title: Hg speciation and stable isotope signatures in human hair as a tracer for dietary and occupational exposure to mercury.
abstract: Exposure of humans and wildlife to various inorganic and organometallic forms of mercury (Hg) may induce adverse health effects. While human populations in developed countries are mainly exposed to marine fish monomethylmercury (MMHg), this is not necessarily the case for developing countries and diverse indigenous people. Identification of Hg exposure sources from biomonitor media such as urine or hair would be useful in combating exposure. Here we report on the Hg stable isotope signatures and Hg speciation in human hair across different gold miner, indigenous and urban populations in Bolivia and France. We found evidence for both mass-dependent isotope fractionation (MDF) and mass-independent isotope fractionation (MIF) in all hair samples. Three limiting cases of dominant exposure to inorganic Hg (IHg), freshwater fish MMHg, and marine fish MMHg sources are used to define approximate Hg isotope source signatures. Knowing the source signatures, we then estimated Hg exposure sources for the Bolivian gold miner populations. Modeled IHg levels in hair correspond well to measured IHg concentrations (R = 0.9), demonstrating that IHg exposure sources to gold miners can be monitored in hair samples following either its chemical speciation or isotopic composition. Different MMHg and inorganic exposure levels among gold miners appear to correspond to living and working conditions, including proximity to small towns, and artisanal vs large scale mining activity.
authors: Observatoire Midi-Pyrénées, Laboratoire de Géosciences Environnement Toulouse, Université Paul Sabatier Toulouse III, 14 avenue Edouard Belin, 31400 Toulouse, France. laffont@get.obs-mip.fr
authors: Laure
authors: L
authors: Laffont
authors: Jeroen E
authors: JE
authors: Sonke
authors: Laurence
authors: L
authors: Maurice
authors: Selma Luna
authors: SL
authors: Monrroy
authors: Jaime
authors: J
authors: Chincheros
authors: David
authors: D
authors: Amouroux
authors: Philippe
authors: P
authors: Behra
mesh_terms: D000818:Animals; D001838:Bolivia; D005399:Fishes; D005506:Food Contamination / Q000032:analysis*; D005602:France; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008628:Mercury / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury