ASSESSMENT OF HEALTH IMPACTS BY CHEMICAL SUBSTANCES, INGESTED WITH DRINKING WATER

The investigation was conducted with the aim to study regional (local) exposure factors for assessing the intake of chemical substances with drinking water by children (3-6 years old) and adults (18-21 years old) in Kazan, in the Republic of Tatarstan. The analysis of levels of non-carcinogenic risk, using local factors and age differences in the exposure of chemical substances, ingested with drinking water, showed that the use of standard values in the risk assessment methodology led to underestimation of the actual health risk for children and adults by the factors of 1.5 and 1.57 at the median level, and by the factors of 1.9 and 1.98 at the level of 95-th percentile. The HI value, in case of chemicals ingestion with drinking water, indicates a health hazard for children, living in the 2ndand the 4th zones (HIме= 11.8 and 9.9; HI 95perс= 14.8 and 12.4) and adults (HIме= 5.52 and 6.64; HI 95perс= 4.42 and 5.59). The main pollutants of drinking water, which cause an increased risk to the health of the population in all zones of Kazan, are oil products, chloroform, nitrates (in NO3) magnesium and fluorides. Keywords: health risk assessment, impact factors, drinking tap water, children, adults