Assessment of Polycyclic Aromatic Hydrocarbons in School Playground Soils in Urban Gwangju, South Korea.

Soil samples from school playground of Gwangju City were analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), and the soil contamination status and the potential cancer risk for students and adults were investigated. Soil samples were collected from 57 sites from 5 districts of Gwangju City in the summer of 2013. Regardless of the sampling site, the ∑PAHs concentrations ranged from 13.2 to 145.5 ng/g (mean 51.2 ng/g). Four and five-ring PAHs were predominant in the soil samples while the fraction of two-ring PAHs was the lowest. Seven carcinogenic PAHs contributed ~ 55% of ∑PAHs in school playground soils. The benzo[a]pyrene (46.4%) and dibenz[a,h]anthracene (41.2%) were the major contributors to toxic equivalent quantity. The strong correlation between carcinogenic PAHs suggested that they originated from the same source either vehicular emission or coal combustion, because they are markers of these pollution sources. The mean cancer risk for students (3.61 × 10-7) and adults (8.41 × 10-6) was in the U.S. EPA safety range (< 10-6).