The testing and chemical analyses of the snow cover have revealed the anomalies for the following chemical elements and substances: F, Cl, SO4, NO2, NO3, PO4, K, Na, NH4, Mo, Mn, Ba, Al, Pb, Ni, Cu, Be, V, Cr, Fe, Si, Zn, Sr, Ti, Hg and petroleum products which all exceed their background concentrations. Air and snow pollution of the lake’s water area has been detected near the littoral residential zones and in the estuary of the Selenga River. The concentrations of NH4, Pb, Be, Hg and petroleum products in the snow water exceed the MAC. According to the research, the current chemical composition of Lake Baikal’s water, in terms of its drinking properties, conforms to health and safety standards due to the accumulation of pollutants in soil and alluvial deposits and their delution with a huge amount of lake water. The only exceptions are some local areas of the shoreline. A local increase in the content of Mn, Pb, Ni, Co, Cr, Zn, Cu which all exceed the MAC and the APC values has been detected near the populated areas. High concentrations of F, Hg, Fe, Pb, Zn, Cu, Ni, PO4, NH4 have been detected in the large rivers flowing into the lake. The landscapes of the rivers’ estuaries serve as a geochemical barrier for toxic substances.