Pollution Characteristic and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Groundwater of Shen-Fu New City in the Hunhe River Basin

Abstract

To protect the safety of water used by the residents in Shen-Fu New City, which is undergoing the process of urbanization, 49 groundwater samples were collected along the Hunhe River Basin and 16 US EPA priority control polycyclic aromatic hydrocarbons (PAHs) were analyzed. The occurrence, distribution characteristics, sources, and potential health risk of drinking the groundwater were also assessed in this study. The results show that PAHs were detected in all samples. The concentration of PAHs ranges from 4.38 to 2005.02 ng·L-1, with an average value of (414.64±526.13) ng·L-1. Based on the comparison of the concentration level with that of other regions, the results in this study indicate a higher pollution level. The 3-4 ring PAHs are dominant; the average value was (190.93±238.96) ng·L-1 and (140.01±234.69) ng·L-1, respectively, accounting for 80% of the total PAHs. The distribution of PAHs in the groundwater is affected by the land use types. The concentration of PAHs is higher when the land use type is cultivated land, while it is lower when it is forest land. The source of PAHs was identified using Principal Component Analysis-Multiple Linear Regression (PCA-MLR). It was revealed that 36.26% of the PAHs are due to incomplete combustion of petroleum and gas, 32.72% are due to coal combustion, 28.17% originate from petroleum spills, and 2.87% are due to traffic emissions. The cancer risk levels releated to drinking the groundwater range from 5.55×10-10 to 5.65×10-6 and 13.60% of the values is in the range of 10-6-10-4. The levels are higher than the baseline of the acceptable risk, indicating the potential cancer risk. More attention should be paid to the quality of the groundwater.