Perrot V., Masbou J., Pastukhov M. V., Epov V. N., Point David, Berail S., Becker P. R., Sonke J. E., Amouroux D. (2016). Natural Hg isotopic composition of different Hg compounds in mammal tissues as a proxy for in vivo breakdown of toxic methylmercury. Metallomics, 8 (2), p. 170-178. ISSN 1756-5901.
Titre du document
Natural Hg isotopic composition of different Hg compounds in mammal tissues as a proxy for in vivo breakdown of toxic methylmercury
Année de publication
2016
Auteurs
Perrot V., Masbou J., Pastukhov M. V., Epov V. N., Point David, Berail S., Becker P. R., Sonke J. E., Amouroux D.
Source
Metallomics, 2016,
8 (2), p. 170-178 ISSN 1756-5901
In the last decade, specific attention has been paid to total mercury (HgT) stable isotopic composition, especially in natural samples such as aquatic organisms, due to its potential to track the cycle of this toxic element in the environment. Here, we investigated Hg Compound Specific stable Isotopic Composition (CSIC) of natural inorganic Hg (iHg) and methylmercury (MMHg) in various tissues of aquatic mammals (Beluga whale from the Arctic marine environment and seals from the freshwater lake Baikal, Russia). In seals' organs the variation in mass dependent fractionation (MDF, delta Hg-202) for total Hg was significantly correlated to the respective fraction of iHg and MMHg compounds, with MMHg being enriched by B3% in heavier isotopes relative to iHg. On the other hand, we observe insignificant variation in Hg mass independent isotope fractionation (MIF, Delta Hg-199) among iHg and MMHg in all organs for the same mammal species and MMHg in prey items. MIF signatures suggest that both MMHg and iHg in aquatic mammals have the same origin (i.e., MMHg from food), and are representative of Hg photochemistry in the water column of the mammal ecosystem. MDF signatures of Hg compounds indicate that MMHg is demethylated in vivo before being stored in the muscle, and the iHg formed is stored in the liver, and to a lesser extent in the kidney, before excretion. Thus, Hg CSIC analysis in mammals can be a powerful tool for tracing the metabolic response to Hg exposure.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Limnologie biologique / Océanographie biologique [034]
;
Pollution [038]
Description Géographique
RUSSIE ; BAIKAL LAC
Identifiant IRD
PAR00014293
