Features of the microelement composition of the liquid phase in snow cover from the towns of Usolye-Sibirskoe and Svirsk

We analyze the chemical composition of the liquid phase in the snow cover from industrial and residential zones, as well as the background region, the water area of Lake Baikal, to assess the atmospheric pollution of the towns of Usolye-Sibirskoe and Svirsk. We have determined the concentrations of trace elements (Fe, Co, Mn, V, Ni, Cu, Zn, As, Cd, Pb, Th, U, and Hg), and most of which have a high toxicity degree. The study has resulted in the identification of priority elements that pollute the atmosphere of the two cities, which differ significantly in the specifics of core enterprises. For the town of Usolye-Sibirskoe, such toxic elements in the liquid phase of snow are Hg, Zn and Pb; for the town of Svirsk - As and V. According to the dispersal halos of pollutants, we determined that their highest concentrations are in the industrial zones of the towns. At the same time, these elements have increased concentrations in the snow meltwater of residential areas of cities as well as in the water area of the Angara River, which is significant as the main source of drinking water supply to the region and fishery facilities. The revealed high concentrations of trace elements in the liquid phase of the snow cover show that a significant part of the pollutants is in the most dangerous dissolved mobile forms. Even in the period of a sharp decrease in the technogenic emission of potentially toxic elements, industrial sites of the investigated cities remain the main sources of air pollution.