Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Soils of Ningbo Area,China

Based on the monitoring data of polycyclic aromatic hydrocarbons(PAHs) in soils from 134 sampling points located in Ningbo,health risk assessment of PAHs for outdoor workers was evaluated,using the method of exposure assessment of Risk Assessment Information System from USA Energy Department and risk equation of Human Health Evaluation Manual of USEPA.The results showed that PAHs in the soils had little risk on human health,since the average noncancer hazard index and the average cancer risk for outdoor workers was 1.09×10-5 and 3.17×10-7 respectively;and the cancer risk of maximum exposure to carcinogenic PAHs for the workers was 1.45×10-6,which was less than the upper limit of acceptable cancer risk of 10-4.However,great attention to the benzo(a) pyrene and dibenzo(a,h) anthracene pollution in the soil should be paid because their contribution rates to the total cancer risk were 65.6% and 20%.Direct ingestion and dermal contact pathways mainly contributed to the noncancer hazard and cancer risk to the outdoor workers,by the reason of their high contribution rates for the noncancer hazard and cancer risk which were as high as 89% and nearly 100% respectively,while direct inhalation pathway relatively brought about very low risk for health.