Biogeochemistry of Cadmium: Anthropogenic Dispersion,Bioaccumulation, and Ecotoxicity

The article considers biogeochemical features of cadmium as one of the most dangerous elements. Data on its concentrations in waters of small lakes in the European Russia (from the tundra to deserts) and large river systems (Volga, Severnaya Dvina, Pechora) are given. It is shown that, despite the relatively low concentrations of the element in waters, its enrichment factor is hundreds and thousands of units, especially in the northern regions and regions subjected to the influence of non-ferrous metallurgy. Data are presented on the bioaccumulation of cadmium within fish body systems, which is determined by the concentration of the element in waters, as well as by the water pH and the calcium content. It is proved that the highest Cd concentrations are accumulated in kidneys and liver of whitefish and salmon, causing pathological disturbances. Data are reported on the accumulation of cadmium in kidneys and liver of human population of the industrially developed Northern region under impacts of copper–nickel smelters. The similarity in tendencies of the Cd accumulation and pathological disturbances in fish and the population consuming water from contaminated sources makes it possible to recommend fish as a bioindicator of the environmental pollution by cadmium.