Chemical forms of mercury in blue marlin billfish : implications for human exposure

Chemical forms of mercury in blue marlin billfish : implications for human exposure Manceau A. auteur aut IRD Azemard S. auteur aut IRD Hedouin L. auteur aut IRD Vassileva E. auteur aut IRD Lecchini D. auteur aut IRD Fauvelot Cécile auteur aut IRD Swarzenski P. W. auteur aut IRD Glatzel P. auteur aut IRD Bustamante P. auteur aut IRD Metian M. auteur aut IRD text journalArticle eng text/pdf born digital access Although fish is an important source of nutrients, including some of the healthiest proteins, long-chain fatty acids, and essential selenium, species at the top of the food chain frequently contain large amounts of toxic mercury (Hg). The provisional tolerable weekly intake (PTWI) of Hg from fish consumption is calculated from the total concentration of Hg and assuming that all Hg is speciated as organic methylmercury (MeHg). Using high energy-resolution X-ray absorption near-edge structure (HR-XANES) spectroscopy, we show that blue marlin (Makaira sp.), a common top predator consumed by humans, contains high concentrations of inorganic Hg(II) complexed as 57 +/- 10% Hg-tetraselenolate [Hg(Sec)(4)] and 43 +/- 10% tiemannite (HgSe). The stable Hg-Se chemical bond likely attenuates the bioavailability of Hg and counteracts some of its health hazards to consumers. Thus, monitoring the concentration of MeHg, rather than total Hg, in top predators such as marlin would provide a more robust measure of potential Hg exposure and may be sufficient for food safety controls. The bonding of Hg atoms to four selenocysteine (Sec) residues in the Hg(Sec)(4) complex severely depletes the stock of bioavailable Se, and quantification shows that blue marlin is not a chief source of dietary Se essential to selenoenzyme synthesis and activity. specialized POLYNESIE FRANCAISE MOOREA 034 038 Environmental Science and Technology Letters 8 5 405-411 2021 2328-8930 https://www.documentation.ird.fr/hor/fdi:010081505 10.1021/acs.estlett.1c00217 2328-8930 [F B010081505] https://www.documentation.ird.fr/hor/fdi:010081505 https://www.documentation.ird.fr/intranet/publi/2021-07/010081505.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-07-02 2025-02-24 fdi:010081505 fre