Health risk from dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in a typical high cancer incidence area in southwest China.

This study was designed to test whether the dietary intake of polycyclic aromatic hydrocarbons (PAHs) is a potential exposure source relating to the high cancer incidence area in southwest China. Duplicate plate method was used to collect food samples in rural and urban sites in the region. Questionnaire surveys were conducted among 300 local residents to obtain their dietary habits and 50 subjects were chosen to collect the samples. The 16 priority PAHs (PAH16) in composite food samples for each individual subject were measured, and non-carcinogenic and carcinogenic risks were analyzed based on the results of Monte Carlo method. The average concentration of the PAH16 in food samples was 12.04 ± 8.52 ng g-1. The life time average daily benzo(a)pyrene equivalent (BaPeq) exposure dose was 6.07 × 10-6 mg kg-1 day-1. Although non-carcinogenic risk was found to be within a controllable range, the average incremental lifetime cancer risk (ILCR) was 3.7 × 10-5 for rural subjects and 6.1 × 10-5 for urban subjects, which is comparable with other regions in China. The serious risk level of 10-4 was exceeded by 10.7% of urban residents and 2.1% of rural residents. This study implies that dietary exposure to PAHs is a potential exposure source to the high cancer in the region, and further cancer risk control strategies need to be formulated.