Polycyclic Aromatic Hydrocarbons in Urban Soils Within the Different Land Use: A Case Study of Tyumen, Russia

The aim of the present study was to evaluate the polycyclic aromatic hydrocarbon (PAH) levels in urban topsoils (0–10 cm) affected by Combined Heat and Power (CHP) plant and oil refinery (Antipinsky Refinery) in comparison with residential area topsoils of Tyumen city. Anthropogenically transformed soils (Urbic Technosols) and artificial loamy soils enriched with organic matter with high pH values are widely represented in the residential area and industrial areas. The 12 priority PAHs in soils were analyzed by HPLC method with fluorescence detection. Urban topsoils of residential area have been contaminated mainly by benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, and benzo[g,h,i]perylene whereas enhanced concentrations of fluorene, phenanthrene, benzo[a]anthracene, and benzo[k]fluoranthene were observed in topsoil of industrial areas. The total amount of PAHs in the background soil was 113.5 μg kg−1. The PAH group composition in all studied soils was expressed mainly by high-molecular polyarenes. The maximum accumulation was found for phenanthrene, pyrene, and fluoranthene. The total amount of PAHs in urban soils exceeded the background level up to three times (341.0 μg kg−1). In the residential area, the total PAH content was twice higher than in the industrial areas of CHP-2 plant and the Antipinsky Refinery (482.7, 275.0, and 273.3 μg kg−1, respectively). The PAH content improvement connected with the soil properties, and it was also affected by long-term and intensive anthropogenic impact. It was found that the level of soil pollution in the residential area is typified as hazardous, in the impact area as moderately hazardous, and in the CHP-2 plant impact area, as permissible.