MONITORING OF POLLUTION OF SNOW COVER THE CITY OF CHITA WITH HEAVY METALS

The forms of zinc, cadmium, lead and copper in the snow cover of Chita were determined. According to the numerical ecological-geochemical and sanitary-hygienic indicators, it was revealed that the city territory is characterized by an average and high level of pollution of snow cover. The main load of toxic ions accounts for the dust fraction of snow. By the dust load Pn the most unfavorable were Central (more than 12 t * km2 * day.) and East (more than 7 t·km2·day.) part of the city of Chita. This is probably due to the high anthropogenic load and the predominant direction of air masses. In addition, the relief and climatic factors that increase the retention of dust and toxic substances in the formation of dense smog are of great importance. The calculated average total load of the studied metals from the dust fraction (Zp = 76,295) corresponds to the low level of pollution, but there were also anomalies where there was a high level of this indicator. The share of water-soluble forms of pollutants does not exceed an average of 0.3% of the total amount of heavy metals. By the average value of the total load index (ZC) the share of water-soluble forms was 10.9%. However, the danger of this polluting factor is high, and when calculating the coefficient of contamination, it is necessary to dilute the melt water with clean water 84 times for fishing purposes and 15 times for economic and drinking use. For all forms of pollutants, the main sources of environmental revenues are thermal power and motor transport enterprises. A significant accumulation of toxic elements in the snow cover of Chita is associated with an unsuccessful location of the main industrial enterprises, the terrain of the territory and specific climatic conditions.