ASSESSMENT OF ECOTOXICOLOGICAL STATE OF SOILS OF THE POLAR URAL AND SOUTHERN YAMAL

Increasing rates of anthropogenic forcing on natural and urban ecosystems in the Arctic requires the development of more detailed environmental monitoring. In this context, studying of contents of background trace elements seems to be actual goal. The goal of this study is an assessment of the content of background heavy metals in natural soils of the Polar Urals (surroundings of mountain Chyornaya), surroundings of Salekhard and foothills of the Polar Urals and urban soils (Kharsaim, Aksarka, Labytnangi, Kharp, Salekhard). Levels of maximum permissible concentrations (MPCs) were established to be exceeded by some elements (As, Ni, Co) in most of soil samples (from both urban and natural environments). It can indicate to high regional background contents for these elements especially in case of natural soils. The highest exceedance of MPCs is typical for soil samples from urban environments. For other studied trace elements (Cu, Zn, Pb, Sr) MPCs are exceeded only in few cases. The highest trace elements content in urban soils is connected with sites with significantly high rates of anthropogenic forcing (chrome-processing factory in Kharp). The highest trace elements content for natural soils can be connected with three soil profile zones: peat-like horizons, stagnic and cryogenic geochemical barriers, and soil horizons with clay texture class. Moreover, we discussed problems of trace elements behavior in conditions of changing climate of the Arctic and permafrost degradation.