Health Risk Assessment of PAHs in Contaminated Soil Based on a Monte Carlo Simulation: a Case of the Guan River Estuary, China

Abstract

To obtain a scientific and reasonable health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil from the Guan River Estuary, a probabilistic risk assessment model was used and each parameter's sensitivity was analyzed. The results showed that the total carcinogenic risk (TCR) of PAHs in contaminated soil was 2.46×10 -3 ±2.12×10 -3 , with a maximum value of 1.11×10 -2 and a minimum value of 7.60×10 -4 . All sampling sites exceeded the upper limit value (10 -4 ) of the acceptable carcinogenic risk recommended by the United States Environmental Protection Agency (USEPA), indicating that the carcinogenic risk of PAHs was very high in the contaminated soil of the Guan River Estuary Industrial Area. The total hazard quotient (THQ) was 4.71×10 -1 ±3.90×10 -1 , with the hazard quotient value at most sampling points being lower than 1. Benzo[a]pyrene(B[a]P) and Dibenz[a,h]anthracene(D[ah]A) were the major contributors to the TCR, with contribution rates of 70.57% and 15.61%, respectively; the main contributing monomers to the THQ were Pyrene(Pyr), Fluoranthene(Fl) and Phenanthrene(Phe), with contribution rates of 34.05%, 29.73%, and 17.20% respectively. The sensitivity of B[a]P and D[ah]A to TCR was the highest, reaching 80.28% and 21.58%, respectively. Body weight had a negative sensitivity (−19.15%). Oral intake and skin contact were the main exposure pathways affecting the TCR and THQ, contributing to exposure at rates of 79.74% and 73.28%, respectively.