Two-Year Monitoring of PAH in the Soils and Pleurozium schreberi under the Impact of Coal Mining

We surveyed PAH concentrations in soils and moss Pleurozium schreberi (Wild. ex. Brid.) Mitt. in the Bolshezemelskaya tundra at the sites affected by coal mining and compared them to the control ecosystems. The samples were collected during 2013-2015 at the distances 0.5, 1 and 1.5 km from the coal mine. During the study period, PAH content in mosses decreased 3 times and PAH content in soils was almost the same. Mass fraction of PAH in soils was stable at different distances from the coal mine. Content of heavy PAH in soils was high near the mine. In Pleurozium schreberi, PAH content decreased when the distance from the coal mine increased. Statistically significant correlations have been found between PAH content in soil and moss due to the fact that Pleurozium schreberi is the main part of vegetation cover and forms upper soil horizons. Diagnostic indexes calculated for PAHs ratios in soil and moss have revealed petrogenic origin of PAH at the control site and at the distances 1 and 1.5 km from the mine. At the distance 0.5 km from the coal mine, PAH content was determined by pyrogenic factor due to motor road. PAH percent proportions were stable over time both in soils and mosses, which suggested the permanence of the main polyarenes sources during the study period.