Occurrence, sources and health risk assessment of polycyclic aromatic hydrocarbons in urban (Pudong) and suburban soils from Shanghai in China

A comprehensive investigation was conducted to the urban (Pudong) and suburban soils in Shanghai. A total of 154 soil samples were analyzed for 26 PAHs including highly carcinogenic dibenzopyrenes (DBPs). The total concentrations ranged from 25.8 to 7380 lig kg-1 for E26PAH5 and 18.8 to 6320 lig kg-1 for 16 USEPA priority PAHs (E16PAHs), respectively. The BaP toxic equivalent (BaPeq) concentrations were between 6.41 and 2880 p,g kg-1 for E24PAH5, 1.11 and 620 pig kg-1 for E16PAHs and 2.72 and 2250 gg kg-1 for E4DBPs. The high PAM contamination in green land soils might originate mainly from local road traffic and industrial activities, and sewage sludge application or waste water irrigation for soil. Seven sources of soil PAHs in Shanghai were identified by positive matrix factorization (PMF) model. The mean risk quotient (m-RQ) values indicated that there were medium to high ecological risks in 9.10% of soil samples, pyrene (Pyr), benzo[b]fluoranthene (BbF) and benz[a]anthracene (BaA) were the major ecological risk drivers under agricultural use. The cancer risk (CR) values were within the acceptable range at 35.7%, 35.1% and 31.2% of sampling sites for children, youths and adults, respectively. The total lifetime carcinogenic risk (TLCR) values at 57.8% of sampling sites were within the acceptable range. Overall, cancer risks of soil PAHs in all sampling sites in the studied area were below the highest acceptable risk, suggesting that soil PAHs are unlikely to pose a significant cancer risk for population based on ingestion, dermal contact and inhalation exposure pathways. (C) 2014 Elsevier Ltd. All rights reserved.