Source contributions of PAHs and toxicity in reed wetland soils of Liaohe estuary using a CMB-TEQ method

16 US EPA priority PAHs were analyzed in surface soils collected from reed wetland of Liaohe estuary. Total concentrations of the sixteen PAHs ranged from 235 ng g− 1 to 374 ng g− 1, while the total concentrations of seven carcinogenic PAHs (cPAHs) varied from 82.6 ng g− 1 to 109 ng g− 1. Toxicity of PAHs was assessed using toxic equivalent quantity (TEQ). The BaP and DBahA were the major contributors to TEQBaP, although IND showed the highest concentration level. Quantitative source apportionment of PAHs and toxicity (i.e. TEQBaP) were performed, using the CMB-TEQ (chemical mass balance model and TEQ) method. Results showed that, the vehicular sources (gasoline and diesel engine emissions) yielded a higher contribution to TEQBaP (95.7%) than that to PAHs (57.1%), while petrogenic source and biomass burning, two important contributors for total PAHs (21.6% and 21.3%, respectively), contributed a little to TEQBaP (3.6% and 0.7%, respectively).