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 (BaP eq ) 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.