Probabilistic Risk Assessment of Consumer Exposure to Particle-Bound PAHs at a Taiwanese Night Market

The purpose of this study was to conduct a quantitative risk assessment for PAH exposure for consumers at a night market in Taiwan. The major methods assessed potential risk under different exposure scenarios based on BaP equivalent concentration (BaPeq) and incremental lifetime cancer risk (ILCR) models. We performed experimental sampling at a night market from 27 October through 22 November 2011 in central Taiwan to analyze time-dependent particle-bound PAHs during open and closed hours. Our study revealed that the ratio of fine particle-bound PAH (<2 μm) concentration to total PAH concentration was nearly 40%; further, the ratio of PAH concentration (<10 μm) to total PAH concentration averaged 84%. This implicates fine particle-bound PAHs caused by cooking in night markets as a matter of health concern. We showed that BaP concentrations at the night market during open hours exceeded suggested permissible levels. Most importantly, we demonstrated that there are 89.05%, 99.62% and <50% probabilities of achieving ILCR levels greater than 10-6 for age groups corresponding to children, adults, and adolescents, respectively; yet, among these there was a zero percent probability of a risk greater than 10-4 (i.e., ILCR=10-4). In contrast, when considering PAH exposure to workers, the cancer risk (95% confidence interval) was estimated at 3.8×10-5 (1.03×10-5–1.34×10-4). Our study suggests that the night market environment poses a potential health risk to its workers. These preliminary results can offer some important information to governments for understanding and controlling pollutants.