Ecological and geological soil assessment of the Loshamye Lake catchment area (national park “Smolensk Lakeland”)

Abstract

The authors conducted the ecological and geochemical study of Lake Loshamye and adjacent territories (national park “Smolensk Lakeland”) to identify the distribution patterns of heavy metals and their associations (Hg, Cr, Mn, Fe, Co, Cu, Zn, As, Cd, Pb, Sr, etc.) in soils of the lake’s catchment area. In 2008, the annual monitoring by the national park revealed abnormally high concentrations of mercury in the water of Lake Loshamye (20 MPC). In subsequent years, the mercury concentration decreased to the minimum natural level. A set of studies in the catchment area and in the lake itself established a probable technogenic source and determined the qualitative and quantitative characteristics of the impact. Scientists studied the soil of the catchment area of the lake to verify the version of the pollutant intake from outside. The article presents the results of the study, a set of mathematical methods of information processing. Authors conducted a correlation, factor and cluster analysis to identify patterns of distribution of heavy metals in soils. Peculiarities of the distribution of most elements in the soil today indicate the presence of a low technogenic impact on the soils of the Lake Loshamye basin regarding the formation of low-contrast anomalies Cu, As, Mn, Pb and Cr, Hg. Patterns of the distribution of heavy metals including mercury in soils and their concentration have natural character. The gross mercury content in soils is significantly lower than the MPC (2100 μg/kg), the median of the sample is 42 μg/kg, which practically corresponds to the world Clark of mercury in soils (40 μg/kg). The research results show that the soils of the lake’s catchment area do not bear traces of anthropogenic impact. This suggests that there are no sources of contamination with mercury and other heavy metals in the study area, and this area is not a transit hub for the movement of the pollutant from the outside, and in 2008 there was probably salvo-type pollution directly into the lake’s water.