Health risks of human exposures to 12 Polycyclic aromatic hydrocarbons (PAHs) in coastal soils of Koh Samed Island (KSI), Thailand, were evaluated after the coastal areas were cleaned up of the 2013 oil-spill contamination. The risk assessment quantified both total cancer and non-cancer risks for four groups of receptors using average PAHs concentrations. Two exposure pathways (incidental ingestion and dermal contact) were selected to evaluate the risks, and three methods were used to calculate the total cancer risks to determine an appropriate assessment method.
The non-cancer risk was represented by the total Hazard Index (HI). The contributions of each PAH to the total cancer risk and total HI were also investigated. The total cancer risk (3.53×10−10 to 9.12×10−8) and total HI (4.35×10−6 to 2.13×10−3) from this work were relatively lower than the USEPA baselines (10-6 for the cancer risk and 1 for the HI) and were quite low when compared with other works in the literature. Benzo(a)pyrene made the highest contribution to the total cancer risk (61.82%), while benzo[g,h,i]perylene made the highest contribution to the total HI (62.41%). In regard to the contributions of the two exposure routes, dermal contact contributed the most to the total cancer risk, while incidental ingestion contributed the most to the total HI.