Characteristics and Influencing Factors of Polycyclic Aromatic Hydrocarbons in Surface Soils from Typical Industrial Areas of Chengdu

Abstract

To improve the pollution signature database for polycyclic aromatic hydrocarbons (PAHs) in typical industrial areas in China, surface soil samples were collected from four typical petroleum-processing industrial areas of Chengdu. The concentration and composition of 16 PAHs listed for prior control by the United States Environmental Protection Agency (US EPA) were determined using high-performance liquid chromatography (HPLC). The result showed that the concentration of PAHs in surface soils of the four industrial areas ranged from 191.2 to 1604.2 μg·kg-1, with an average of (583.6±365.6) μg·kg-1. The PAHs in the present study were mainly composed of medium-molecular-weight PAHs and high-molecular-weight PAHs. Among the PAHs detected in the study soils, phenanthrene (PHE), pyrene (PYR), fluoranthene (FLT), and benzo[b]fluoranthene (BbF) were the major pollutants presenting a potential pollution risk. Selected mathematical statistical methods were used to analyze the relationship between soil organic matter (SOM), soil particle diameter and PAH content, and to simultaneously identify the factors influencing PAHs in the soils. SOM was shown to be a favorable absorbent, predicting the migration and transformation behavior of PAHs in surface soil and soil ecological risk (i.e., PAH carcinogenicity) to some extent. Compared with SOM, the correlation between PAHs and soil particle size was relatively low, showing a weak positive correlation with silt, a weakly negatively correlation with clay, and no significant correlation with sand. These results provide a basis for soil remediation practices and further research in such industrial areas.