[Characterization and potential risks of polycyclic aromatic hydrocarbons in green space soils of educational areas...

Pollution of green space by polycyclic aromatic hydrocarbons (PAHs) in education area may pose a potential impact on the faculty, students, and staffs. To study the characterization, influencing factors, sources and risks of soil PAHs in Beijing educational areas, the concentrations of 16 priority PAH identified by United States Environmental Protection Agency (USEPA) in green spaces of 20 schools and academies were determined. The total PAHs concentration ranged from 194 microg x kg(-1) to 6 988 microg x kg(-1), with a mean of 1 637 microg x kg(-1). Middle and high molecular weight PAHs (4-6 rings) accounted for 85% of the total PAHs concentration. Coal combustion for winter heating and food supply were the main sources of PAHs in Beijing educational areas. Based on the Cluster analysis, the transportation and accumulation of NAP were distinguished from other 15 PAH congeners. No significant correlation between PAHs and soil organic matter (SOM) was found except for NAP, suggesting that most of the PAH congeners were derived from direct deposition of urban sources. The integrated lifetime cancer risks (ILCRs) associated with exposure to soil PAHs in Beijing educational areas were acceptable, but the indirect effects should not be ignored.