Geo-ecological characteristics of the small lakes bottom sediments in the North of Western Siberia

The article analyzes and provides data on the processes of accumulation of heavy metals by bottom sediments from the point of view of environmental assessment. The purpose of this paper is to identify the degree of anthropogenic influence on the lakes of the Tazovskiy and Surgut districts, and assess the ecological state of water bodies and adjacent territories. The main processes occurring in natural reservoirs, which lead to the transfer of toxicants into the environment, are considered. The data of quantitative chemical analysis of bottom sediments of two groups of natural reservoirs with an assessment of their ecological state according to the results of statistical processing of the measured values were obtained. Excess concentrations of metals were recorded: for mobile forms – 2200 times for Fe, 1050 times for Mn, 35 times for Cr, 20 times for Co, up to 15 times for Ni, 5 times for Cu, 3 times for Pb, for acid-soluble forms – 45 000 times for Fe, 550 times for Pb, up to 75 times for Ni, 525 times for Mn, 105 times for Cr, 50 times for Cu, 16 times for Co. The geochemical interpretation of the results of the factor analysis is presented.