Features of fractional composition of polycyclic aromatic hydrocarbons and multielement contamination of soils of urban territories and their hygienic characteristics (on the example of soils of functional zones of Saint-Petersburg)

Abstract

This study is devoted to the investigation of quantitative and qualitative composition and distribution of polycyclic aromatic hydrocarbons (PAHs) in urban soils on the example of recreational, residential and industrial areas of Saint-Petersburg (Russia). The evaluation of soil contamination levels with heavy metals and metalloids of the first and second classes of hazard is given as well. Total PAH content in soils of the studied area in most cases exceeds international soil quality guideline values (1 mg/kg), varying from 0.67 to 17.45 mg/kg. In most samples benzo[a] pyrene concentrations were found to be higher than MPC for this substance in soil. Calculated BaP-equivalents of PAHs indicate to the high carcinogenic risk for health, associated with soil contamination. Mean PAH concentrations in soil differ authentically between various types of functional zones and in the whole of the city. The significant positive correlation between soil organic content and PAH levels in soils was revealed in most samples. Calculated values of the total index of soil contamination (Zc) by heavy metals and metalloids were characterized by low values (47.28-121.14), that corresponds to the category of dangerous pollution (32 < Z < 128).