Chemical Forms of Mercury in Human Hair Reveal Sources of Exposure.
Humans are contaminated by mercury in different forms from different sources. In practice, contamination by methylmercury from fish consumption is assessed by measuring hair mercury concentration, whereas exposure to elemental and inorganic mercury from other sources is tested by analysis of blood or urine. Here, we show that diverse sources of hair mercury at concentrations as low as 0.5 ppm can be individually identified by specific coordination to C, N, and S ligands with high energy-resolution X-ray absorption spectroscopy. Methylmercury from seafood, ethylmercury used as a bactericide, inorganic mercury from dental amalgams, and exogenously derived atmospheric mercury bind in distinctive intermolecular configurations to hair proteins, as supported by molecular modeling. A mercury spike located by X-ray nanofluorescence on one hair strand could even be dated to removal of a single dental amalgam. Chemical forms of other known or putative toxic metals in human tissues could be identified by this approach with potential broader applications to forensic, energy, and materials science.
ISTerre, Université Grenoble Alpes, CNRS, CS 40700, 38058 Grenoble, France.
Alain
A
Manceau
Laboratoire Chrono Environnement, Université de Franche-Comté, CNRS , 25030 Besançon, France.
Mironel
M
Enescu
ISTerre, Université Grenoble Alpes, CNRS, CS 40700, 38058 Grenoble, France.
Alexandre
A
Simionovici
ISTerre, Université Grenoble Alpes, CNRS, CS 40700, 38058 Grenoble, France.
Martine
M
Lanson
Laboratoire EPOC, Université de Bordeaux, CNRS , 33120 Arcachon, France.
Maria
M
Gonzalez-Rey
European Synchrotron Radiation Facility (ESRF), 71 Rue des Martyrs, 38000 Grenoble, France.
Mauro
M
Rovezzi
European Synchrotron Radiation Facility (ESRF), 71 Rue des Martyrs, 38000 Grenoble, France.
Rémi
R
Tucoulou
European Synchrotron Radiation Facility (ESRF), 71 Rue des Martyrs, 38000 Grenoble, France.
Pieter
P
Glatzel
Department of Earth and Environmental Sciences, MC-186, 845 West Taylor Street, University of Illinois at Chicago , Chicago, Illinois 60607, United States.
Kathryn L
KL
Nagy
Institut Européen de Chimie et Biologie, Université de Bordeaux, CNRS , 2 rue Escarpit, 33607 Pessac, France.
Jean-Paul
JP
Bourdineaud
D000818:Animals; D004784:Environmental Monitoring; D005399:Fishes / Q000378:metabolism; D005506:Food Contamination; D006197:Hair / Q000737:chemistry; D006801:Humans; D008628:Mercury; D008767:Methylmercury Compounds; D017747:Seafood
D008767:Methylmercury Compounds; D008628:Mercury