Application of the PDMS Passive Sampling Method to Assess Bioavailability and Health Risks Associated with PAH-Contaminated Soil

Integrating bioavailability into risk assessments is an effective way to objectively assess human health risks. In this study, the bioavailability of 16 polycyclic aromatic hydrocarbons (PAHs) in contaminated soil from a coking plant was evaluated using the polydimethylsiloxane (PDMS) passive sampling method. The results showed that the bioavailability factor (BAF) of each PAH, predicted using PDMS fibers, ranged from 0.46% to 9.74%. The PDMS passive sampling method was more stable in testing the bioavailability of PAHs with more than 4 benzene rings; a preliminary relationship was established between the BAF and the log value of the octanol-water partition coefficient (logK(ow)). After considering their bioavailability, the carcinogenic risks (CRs) and non-carcinogenic hazard quotients (HQs) associated with the 16 PAHs were reduced by 1 to 2 orders of magnitude. Only the health risks associated with benzo(a)pyrene and dibenzo(a,h)anthracene exceeded the acceptable level. The PDMS passive sampling method provides a useful tool for estimating oral bioavailability, and incorporating its results into human exposure testing can help to refine the health risk assessment of contaminants through oral ingestion.