ASSESSMENT OF THE INFLUENCE OF PERM NATURAL GEOCHEMICAL PROVINCES ON THE QUALITY OF DRINKING WATER AND FORMATION OF CANCEROGENIC RISK FOR POPULATION HEALTH
The comparing of the data about geochemical provinces of the Perm region and the locations of a number of surface water intakes allowed us to distinguish several major water sources of drinking water supply in the region, located in the areas with high natural concentrations of heavy metals - cadmium, nickel, lead, chromium and arsenic. It is found that the highest concentrations of cadmium and lead are identified in drinking water of those provinces where their natural levels are the highest. The exceeding health standards of the content of nickel and arsenic (up to 4PDK) in drinking water in the absence of man-made sources of these components were also revealed. It`s determined that the presence of metals, even if their year average level is less than hygienic standards, causes unacceptable carcinogenic risk to the health of the population (from 7.35 * 10-4 to 4.0 * 10-3), which requires additional sanitary measures to protect public health. The recommendations to take into account the geochemical characteristics of the area in composing control programmes of drinking water quality are given.