Polycyclic Aromatic Hydrocarbon (PAH) Contamination in the Urban Topsoils of Shenyang, China

Polycyclic aromatic hydrocarbons (PAHs) in the surface urban soils of Shenyang in Northeastern China were investigated. The total concentration of the PAHs ranged from 0.09 to 8.35 mg kg-1, with an average value of 1.51 +/- 1.64 mg kg-1. 35-ring PAHs accounted for 90% of total PAHs. The functional areas, such as the industrial regions (4.95 mg kg-1) and main roads (1.56 mg kg-1), as well as the administrative divisions, including the districts of Shenhe (1.49 mg kg-1), Heping (2.08 mg kg-1), and Tiexi (2.14 mg kg-1), were heavily polluted by PAHs. The diagnostic ratios and principal component analysis (PCA) for PAHs indicate that the pollutants probably originated primarily from coal combustion and petroleum sources. The Nemerow composite index, used to assess environmental quality, shows that the soil samples were heavily polluted with PAHs, and although 52.8% of the soil sampling sites were safe, 47.2% of the soil sampling sites registered different grades of PAH pollution. The PAH contamination in Shenyang emphasizes the need for controlling fossil fuel combustion and traffic exhaust.