The Influence of Land Use on the Concentration Levels and Distribution Characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in Korea

We investigated soil contamination depending on the land use by examining the contamination levels and distribution characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in the national soil. Total PAHs (the sum of 16 PAH concentrations) and carcinogenic PAHs (the sum of seven carcinogenic PAH concentrations) were 8.50~3,437.16 µg/kg and 2.94~2,136.96 µg/kg, respectively. The concentration of benzo(a)pyrene, one of the contaminants regulated by the soil quality standard in the nation, was ND~924.73 µg/kg. Its maximum value of 924.73 µg/kg was detected in railroad (Region 3) and is approximately 13 % of the standard value for Region 3 (i.e., 7 mg/kg). We also investigated the characteristics of contamination sources of PAHs in soil of the upland, forests, roads, and railroads, examining the fraction distribution of PAHs concentration by the number of benzene rings against the total PAHs concentration. The results demonstrate that the mean fraction of 4~6-ring PAHs against total PAHs concentration in soil was in the range of 51.8~80.7 % with relative abundance of high-molecular PAHs, showing that the origin of contamination is under the category of combustion sources. When the molecular indices (Flu/(Flu/Pyr), Ant/(Ant+Phe), InP/(InP+BP), and BaA/ (BaA+Chr)) were applied, they were also categorized as petroleum-based combustion sources. The individual PAH concentrations in soil by the land use were grouped into Regions 1, 2, and 3, which are statistically treated and are the parts of the national category system of soil quality standard. As a result, the concentration level of 16 PAHs wa