Population health risk related to increased content of benzpyrene in soil

The article deals with the problem of soil contamination with benzpyrene within sanitary-hygienic zone of an oil refinery plant. We proved that benzpyrene penetrated into soils due to oil-containing wastes and sedimentation of polycyclic aromatic hydrocarbons from powder-gas discharges on soil surface. Benzpyrene concentration detection at the boundary of a sanitary-hygienic zone provides guidelines for determining discharges spread into the atmosphere from stationary sources; it also serves as an indirect parameter characterizing soil self-purification intensity. We treated benzpyrene content in soils as an informative indicator showing soil horizon contamination with polycyclic aromatic hydrocarbons and heavy oil fractions. Over 2015-2016 66 soil samples were taken and analyzed. We detected benzpyrene concentration with Agilent Technologies 7820A GC System «Maestro» gas chromatograph with mass-selective detector Agilent Technologies 5975 Series MSD in full conformity with ISO 18287: 2006. We compared actual benzpyrene concentrations with maximum permissible concentration (MPC = 0.02 mg/kg), confirmed by Hygienic Standard 2.1.7.2041-06. The results of analyzing the samples as per benzpyrene content revealed that it was higher than maximum permissible concentration (MPC) in all of them. Share of samples with benzpyrene content higher than 1.5 MPC varied from 54.5 % to 90.9 % in different seasons. Some places within sanitary-hygienic zone had high benzpyrene concentration in soils reaching 9.85 MPC. High benzpyrene content in soils proves there is persistent soil horizon contamination with polycyclic aromatic hydrocarbons and soil self-purification slows down. And this, in its turn, causes carcinogenic health risk occurrence (1.08×10-3 - 6.55×10-3).