Levels and distributions of polycyclic aromatic hydrocarbons in agricultural soils in an emerging e-waste recycling town in Taizhou area, China

Abstract

The present study investigated the levels, distributions, profiles and possible sources of polycyclic aromatic hydrocarbons (PAHs) in agricultural soils around Zeguo, an emerging e-waste recycling town in Taizhou area, China. Concentrations of sixteen USEPA priority PAHs and soil organic matter were analyzed in 59 agricultural soil samples. The total PAH concentrations ranged from 262.6 to 3,420.2 microg/kg, with the average values in a gradually descending order: agricultural soil near e-waste recycling plants and workshops (1,336.0 microg/kg) > agricultural soil in villages with open burning and e-waste recycling activities (945.8 microg/kg) > agricultural soil in other villages (466.5 microg/kg). Analysis of the distribution patterns of the PAHs showed that phenanthrene, anthracene, fluoranthene and pyrene were the dominant species. The significant correlations among individual, low-molecular-weight (LMW), high-molecular-weight (HMW) and total PAHs and the very similar PAH profiles in the three sampling areas indicated that the PAHs might have come from similar sources. The ratios of Anthracene to sum of Anthracene and Phenanthrene concentrations (Ant/(Ant+Phe)) and fluoranthene to sum of fluoranthene and pyrene concentrations (Flt/(Flt+Pyr)) were calculated and principal component analysis (PCA) was performed and the results suggested that an anthropogenic source such as the combustion of a petroleum product or coal during the e-waste recycling process seemed to be the main source of PAHs in the Zeguo agricultural soil. In conclusion, soils taken from Zeguo agricultural areas were considered to be heavily polluted, and the emerging e-waste recycling activities had definite effects on PAH soil concentrations.