Soil sealing degree as factor influencing urban soil contamination with polycyclic aromatic hydrocarbons (PAHs)

The objective of the study was to determine role of soil sealing degree as the factor influencing soil contamination with polycyclic aromatic hydrocarbons (PAHs). The study area included four sampling sites located within the administrative boundaries of the Toruń city, Poland. Sampling procedure involved preparing soil pits representing three examples of soil sealing at each site: non-sealed soil as a control one (I) and two degrees of soil sealing: semi-pervious surface (II) and totally impervious surface (III). Together with basic properties defined with standard procedures (particle size distribution, pH, LOI, content of carbonates) content of selected PAHs was determined by dichloromethane extraction using gas chromatography with mass spectrometric detection (GC-MS). Obtained results show that urban soils in the city of Toruń are contaminated with polycyclic aromatic hydrocarbons. Soil sealing degree has a strong influence on the soil contamination with polycyclic aromatic hydrocarbons. Totally sealed soils are better preserved from atmospheric pollution including PAHs. Combustion of grass/wood/coal was the main source of determined PAHs content in examined soils.