Assessment of the content of heavy metals and polycyclic aromatic hydrocarbons in the soil of the city of Svirsk, Irkutsk region

Abstract

Introduction. One of the environmental problems is the contamination of soil cover with toxicants. The soil performs the functions of a biological absorber, destroyer and neutralizer of various contaminants, it has the most important role in the life of society. The aim of the study is to assess the quantitative content of mobile forms of heavy metals and polycyclic aromatic hydrocarbons in the soil in the urbanized territory of the Irkutsk region on the example of the city of Svirsk. Materials and methods. Content of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in the soil of Svirsk, selected in various parts of the city (multi-storey buildings, private sector, industrial zone, forest park zone) and in the background point outside the city was studied. The determination of heavy metals was carried out by atomic absorption spectrometry, PAH - by gas chromatography-mass spectrometry. Results. The levels of metals in the soil samples varied within 2.9-366.7 mg/kg for lead; 0.82-3.1 mg/kg for copper; 0.2-36.0 mg/kg for zinc; 3.5-67.9 mg/kg for iron; 65.5-149.7 mg/kg for manganese; 0.12-4.8 mg/kg for chromium and 0.04-0.28 mg/kg for cadmium. The content of benzo(a)pyrene and the amount of PAHs ranged from 1.1 to 387.3 and from 61 to 4600 µg/kg, respectively. Limitations. The limitations of the study are related to the need for further study of the content of these pollutants in biological media Conclusion. Maximum allowable values were found to be exceeded in 90.9% of samples for lead (maximum excesses were 52.4-61.1 MPC), in 72.7% of samples for benzo(a)pyrene (maximum excesses were 9.1-19.4 MPC), as well as single excesses for copper (1.03 MPC) and zinc (1.3 and 1.6 MPC).