Total mercury content in soils and lake sediments of Vilkitsky Island (Kara Sea)

Abstract

Mercury threatens Arctic ecosystems due to its well known deleterious effects. The development of energy resources in the Russian Arctic is currently being planned, which will inevitably be accompanied by emissions of heavy metals into the environment, but little is known about the distribution of mercury in soils of the permafrost regions. Total mercury (THg) concentrations were investigated in soils and lake sediments of Vilkitsky Island located in remote area of the Arctic. The concentration of mercury in soils varied from 1 to 36,6 ng g−1, in lake sediments – from 2.0 to 5.8 ng g−1. In sandy soils of the iseland the concentration of THg was minimal and was usually not higher than10 ng g−1, whereas in loamy soils it was 3.5 times higher. Correlation analysis has shown that THg concentration depended primarily on particle size distribution, in a lesser degree – on total carbon and total nitrogen concentrations. The soils of Viltisky Island have one of the lowest mercury concentration in comparison to soils of other Arctic territories, because of the predominance of sandy marine sediments and low soil organic matter content. Under influence of human activities, THg content has increased three-fold on average. The highest concentrations were observed in soils of an abandoned polar station. Calculation of CF and Igeo coefficients demonstrated the high level of mercury pollution on local sites. The maximum content of mercury (25.7-36.7 ng g-1) was observed in coastal sediments. It is assumed that the increased mercury content is a consequence of translocation. Thus, the coastal areas of the Arctic islands are at the greatest danger of pollution.