Polycyclic Aromatic Hydrocarbons in Surface Soils of a University Campus: Concentrations, Distribution, Sources and Potential Risk

The concentrations, distribution, possible sources and the potential risk of polycyclic aromatic hydrocarbons (PAHs) in surface soils were studied in Kunming University of Science and Technology, situated in Kunming, China. 15 PAHs were analysed in 6 surface soil samples (0-5 cm layer) collected from six types of land uses in the university campus. Meanwhile, the potential sources of PAHs in surface soils have been investigated by PAH composition ratios and isomer ratios. The total concentrations of 15 PAHs ranged from 272.1 to 2,521.6 ng/g (dry weight basis), and different land uses followed the increasing order of teaching area (272.1 ng/g) <; Baini Hill (752.8 ng/g) <; canteen area (1,323.6 ng/g) <; teacher residential area (1,562.2 ng/g) <; student dormitory area (1,916.9 ng/g) <; school gate (2,521.2 ng/g). The results of sources identification suggested that PAHs in surface soils of Kunming urban area were greatly affected by combustion activities and mainly from coal combustion and vehicular traffic. In addition, the toxic equivalency factors (TEFs) were used to estimate benzo[a]pyrene-equivalent concentration in surface soils of Kunming, which indicated a potential risk to human health.