Evaluation of Inhalation Exposure to Carcinogenic PM10-Bound PAHs of People at Night Markets of an Urban Area in a Metropolis in Eastern China

ABSTRACT

Inhalable particle bounded carcinogenic polycyclic aromatic hydrocarbons (PAHs) pose high health risks to both food service workers and consumers cooking or purchasing late night snacks, respectively, in night markets because PAHs are generated in abundance during thermal cooking processes such as barbecue grilling. In the present study, sixteen carcinogenic PAHs in PM₁₀ collected during open hours from eight night markets in an urban area of a metropolis in eastern China were determined. The total concentration of PAHs (ΣPAH) ranged from 145 to 1340 ng m^–3, with an arithmetic mean of 828 ± 360 ng m^–3. Five- and six-ringed PAHs were predominant in the composition, implying a combination of sources including cooking and traffic. Low coefficient of divergence values for individual PAH homologous among all sampling sites indicated similar sources. The occurrence of PM₁₀-bound PAHs appeared to depend on the gas-particle partitioning processes and emission sources according to the results of principal component analysis (PCA). The daily inhalation rate of particle and predicted gaseous benzo[a]pyrene (BaP)-equivalent adjusted PAHs (BaP_eq) for the workers due to occupational exposure was 0.451–3.43 µg day^–1. Correspondingly, the occupational exposure risk for workers with one year of service was less than the acceptable risk level (10^–6). However, the risk for people who had worked for more than 3 years exceeded 10^–6 but was less than the priority risk level (10^–4). For consumers, the maximum consumption time (t_max) for each time under the acceptable risk level would increase with an increase in age, and the exposure risk for infants, toddlers and children is high when PM₁₀-bound PAHs are inhaled. We recommend that t_max should be less than 1 hour for consumers under 25 years old. Therefore, our results indicate that both workers and consumers in the night markets have high cancer risks due to inhalation of PM₁₀-bound PAHs.