Concentration and Risk Evaluation of Polycyclic Aromatic Hydrocarbons in Urban Soil in the Typical Semi-Arid City of Xi’an in Northwest China
Department of Environmental Science and Engineering, School of Geography and Tourism, Shaanxi Normal University, Xi’an 710119, China
International Joint Research Center of Shaanxi Province for Pollutant Exposure and Eco-Environmental Health, Xi’an 710062, China
Author to whom correspondence should be addressed.
Int. J. Environ. Res. Public Health 2018, 15(4), 607; https://doi.org/10.3390/ijerph15040607
Received: 11 February 2018 / Revised: 15 March 2018 / Accepted: 20 March 2018 / Published: 27 March 2018
(This article belongs to the Special Issue Proceedings of 2nd International Symposium on Environment Science and Health)
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, presenting potential threats to the ecological environment and human health. Sixty-two urban soil samples were collected in the typical semi-arid city of Xi’an in Northwest China. They were analyzed for concentration, pollution, and ecological and health risk of sixteen U.S. Environmental Protection Agency priority PAHs. The total concentrations of the sixteen PAHs (Σ16PAHs) in the urban soil ranged from 390.6 to 10,652.8 µg/kg with an average of 2052.6 µg/kg. The concentrations of some individual PAHs in the urban soil exceeded Dutch Target Values of Soil Quality and the Σ16PAHs represented heavy pollution. Pyrene and dibenz[a,h]anthracene had high ecological risk to aquatic/soil organisms, while other individual PAHs showed low ecological risk. The total ecological risk of PAHs to aquatic/soil organisms is classified as moderate. Toxic equivalency quantities (TEQs) of the sixteen PAHs varied between 21.16 and 1625.78 µg/kg, with an average of 423.86 µg/kg, indicating a relatively high toxicity potential. Ingestion and dermal adsorption of soil dust were major pathways of human exposure to PAHs from urban soil. Incremental lifetime cancer risks (ILCRs) of human exposure to PAHs were 2.86 × 10−5 for children and 2.53 × 10−5 for adults, suggesting that the cancer risk of human exposure to PAHs from urban soil is acceptable.