Mercury in the lake sediments of the Russian sector of Arctic

Theme 1. Environmental protection
Session Name 1.9 Climate change, forests and other ecosystems health in the Arctic region
Datetime Sep 07, 2018 10:30 AM - 10:45 AM (UTC +3)
Presentation Type Oral
Author(s) Valery Udachin (Institute of Mineralogy, Ural Brach of Russian Academy of Sciences, Russian Federation), Yury Tatsy (Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academy of Sciences, Russian Federation), Dmitry Bolshiyanov (Arctic and Antarctic Research Institute, Russian Federation)
Abstract text

Atmospheric mercury flux to sedimentation basins of Arctic lakes is of undoubted interest because it make possible to evaluate the current anthropogenic Hg exposure on ecosystems. The Arctic is of particular concern about environmental risks from Hg, because the region may be especially vulnerable to global Hg pollution. There is currently no clear understanding of Hg sources in Arctic. Instrumental data of atmospheric Hg flux for Arctic, environmental archives (lake sediments) are particularly important sources of data in this region for providing flux history.

Determination of total Hg have been performed for two lake sediment cores: Lake Molo on the Samoylovsky Island (Lena River Delta, 72022'N, 126028'E) and Lake Izmenchivoye (Severnaya Zemlya Archipelago, 79007'N, 95007'E). Discreteness of sampling was 0.5 cm. Concentrations of Hg were determined by pyrolysis with amalgamation on gold and atomic absorption detection. The rate of sedimentation for thermokarst Lake Molo was estimated from the isotope 210Pb using CRS model (Appleby et al., 2001). It was equal to 0.23 mm/y. For industrial period (sediments younger than 1900) and pre-industrial period concentrations of mercury were 38 and 39 ng/g, respectively. For Lake Izmenchivoye these values were 52 and 51 ng/g, respectively.

For lakes in the Russian Arctic, which from 9 to 10.5 months are covered with ice, background values of Hg are characteristic. This distinguishes them from similar lakes in West Greenland (Bindler etal., 2001) where the pronounced effect of the atmospheric intake of Pb and Hg is characteristic.

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