Assessment of chemical pollution level of soils in Petropavlovsk-Kamchatsky City

The level of chemical pollution of the surface part of soils with heavy metals (Co, Mo, Cd, Ba, Cu, Ni, Pb, Cr, Zn and Mn) and petroleum products in Petropavlovsk-Kamchatsky in 2023 was determined. The use of various ecological and geochemical approaches for a comprehensive assessment of the state of the urban environment revealed different degrees of pollution in the study areas depending on the pollutant and the calculated indices. The maximum content of class I hazard pollutants in the soil was 1546 mg/ kg for petroleum products, 3.37 mg/kg for Cd, 248 mg/kg for Pd, and 571 mg/ kg for Zn. Anthropogenic sources of their intake were identified. In general, the comprehensive assessment conducted using geochemical, toxicological indices and phytotesting determined the city’s soils as slightly polluted. At the same time, in certain areas associated with the automobile infrastructure and fuel and energy complex enterprises, a high degree was established both by comprehensive indices and by external pollutants (Pb, Zn). The maximum soil pollution with brittle metals was noted when calculating the ecological and geochemical indices and amounted to 13% (by the Zc index) to 80% (by the NPI index) of the total number of measurements. The excess of oil products in soils was insignificant and 6.6% of soils were determined as polluted. Comparative analysis of integral indicators of the current ecological state of soils. Petropavlovsk-Kamchatsky has identified a number of methodological problems in assessing the level of pollution. For the regional center and Kamchatka Territory as a whole, one of the main difficulties is taking into account regional geochemical levels of both heavy metals and oil products in soils. Given the influence of active volcanism, both in the geological past and in the present of the peninsula, identifying background values for the content of a number of pollutants is an urgent task for conducting objective environmental monitoring of the soil cover in the region.