City Soil Ranking According to the Level of Pollution: Approach Based on the Health Risk Assessment of the Child Population

Abstract

Assessment of soil pollution with chemicals in certain districts (zones) of the city of Kazan was performed according to the data of the social-hygienic monitoring of the FBHI “Center of Hygiene and Epidemiology in Republics of Tatarstan” for the period of 2010 -2016. The indices of complex assessment of soil pollution with heavy metals (HM) and oil products in the zones under study did not exceed the established regulations. The results showed uneven distribution of pollutants on the territory of the city zones. The 3-rd zone (the Vakhitovsky district) is different, there the major contribution to the total risk level is made by lead (Pb) – 51.4%, cadmium (Cd) - 36.9%, mercury (Hg) – 3.53%, oil products, and copper (Cu) – 2.6%. The level of non-carcinogenic risk for the health of the child population aged 3-6 years old with application of regional exposure factors (THI 1.0 and less) corresponds to the target risk level. The maximum contribution to THI is caused by the dermal route of the oil products’ entry (from 94.0 to 98.9 %). Ranking of the city territory according to the total hazard quotient with the account of all routes of the chemicals’ entry identified two zones ranking first in the risk level: the 2-nd zone (the Sovetsky district) and the 3-rd zone (the Vakhitovsky district). The results indicate the necessity of revising the approaches to assessment of possible health risks associated with oil hydrocarbons on the basis of new scientific data.