ON THE PREVALENCE OF BACKGROUND AND TECHNOGENICALLY DEPENDENT CONCENTRATIONS OF HEAVY METALS IN RIVER WATERS

Features of the prevalence of Cd and Pb dissolved forms in the water of sections of the Oka river and other rivers of the Russian Plain are considered. The influence of anthropogenic wastewater (industrial, municipal and agricultural) containing heavy metals is clearly manifested only in certain sections of the rivers of central Russia (Oka River, Volga River, and Moscow River) against the background of natural landscape and geochemical processes. An attempt is made to develop approaches to assessing the degree of anthropogenic influence on the water composition of various river sections, including those remote from pollution zones. An ecological and geochemical lead-cadmium indicator is proposed, which makes it possible to assess the anthropogenic impact and divide river sections into 3 categories (strong, medium and weak pollution, respectively). The river sections with low anthropogenic pollution have high values of this indicator corresponding to waters with the background (or close to background) concentration. A decrease in the indicator values means an increase in the role of anthropogenic effluents