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New insight into biomarkers of human mercury exposure using naturally occurring mercury stable isotopes.

Sherman-LS; Blum-JD; Franzblau-A; Basu-N

Environ Sci Technol 2013 Apr; 47(7):3403-3409

http://dx.doi.org/10.1021/es305250z

20044014

Human exposure to methylmercury (MeHg) and elemental mercury vapor (Hg(0)(g)) are often estimated using total Hg concentrations in hair and urine, respectively. We investigated whether Hg stable isotopes could be used to better distinguish between exposure to Hg(0)(g) versus MeHg. We found that hair from North American dental professionals was characterized by high positive delta(199)Hg values (mean = 1.86 0/00, 1 SD = 0.12 0/00, n = 11). This confirms that among people who regularly consume fish, total Hg concentrations in hair reflect exposure to MeHg. In contrast, we found that urine from the same individuals was characterized by a range of delta(199)Hg values (0.29 to 1.77 0/00, 2 SD = 0.06 0/00, n = 12) that were significantly correlated to the number of dental amalgams in each individual's mouth. We hypothesize that fish-derived MeHg is demethylated within the body, causing mass-dependent fractionation and the excretion of inorganic Hg in urine. Mercury in urine therefore represents a mixture of demethylated fish-derived MeHg and amalgam-derived inorganic Hg. We estimate that the majority (>70%) of Hg in urine from individuals with <10 dental amalgams is derived from ingestion of MeHg in fish. These data suggest that within populations that consume fish, urine total Hg concentrations may overestimate Hg exposure from personal dental amalgams.

Dental-materials; Dentists; Mercury-compounds; Exposure-assessment; Employee-exposure; Environmental-exposure; Humans; Biomarkers; Methyl-compounds; Urinalysis; Food; Inorganic-mercury; Chemical-analysis; Isotope-effect; Inorganic-mercury; Inorganic-mercury-compounds; Foodstuff; Analytical-processes; Animal-products

ESTHAG

22967-92-6; 7439-97-6

20130402

Journal Article

Grant

2013

Grant-Number-T42-OH-008455

7

0013-936X

Environmental Science and Technology

MI

University of Michigan, Ann Arbor