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Laffont Laure Menges Johanna Goix Sylvaine Gentès Sophie Maury-Brachet Régine Sonke Jeroen E. Legeay Alexia Gonzalez Patrice Rinaldo Raphaëlle Maurice Laurence 《Environmental science and pollution research international》2021,28(43):60609-60621
Environmental Science and Pollution Research - The aim of the study was to determine if gold-mining activities could impact the mercury (Hg) concentrations and isotopic signatures in freshwater... 相似文献
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Atmospheric Mercury Depletion Events (AMDE) occur in Arctic and Antarctic regions during polar sunrise. During AMDE, reactive gaseous Hg is rapidly formed through in-situ oxidation of gaseous Hg0 by halogens, notably atomic Br and radical BrO. This leads to high Hg deposition fluxes yet an unknown fraction of deposited Hg is reemitted to the atmosphere through subsequent photo-reduction, so that the net deposition flux related to AMDE is not well constrained. Here, Hg and halogens were measured in lichens hanging in tree branches around Hudson Bay where AMDE were reported. Hg concentrations are strongly correlated to halogen elements Br, Cl and I (r2 of 0.91, 0.76, 0.81) and decrease with distance from Hudson Bay. We interpret this trend as the result of AMDE, supported by a 1D numerical Br and BrO oxidation model for Hg0. Organic carbon normalized Hg contents of down-core lake sediments reported in the literature also show a decreasing trend away from Hudson Bay. Combined observations suggest that at least 50% of Hg deposited during AMDE is reemitted to the atmosphere. Finally, the latitudinal Hg gradient observed in lake sediments suggests that AMDE were active in the Hudson Bay area during the last 90 to 200 years. 相似文献
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