Exposure to Ambient Polycyclic Aromatic Hydrocarbons on Citizens in Tianjin, China

People exposure to ambient polycyclic aromatic hydrocarbons (PAHs) in Tianjin area was estimated based on field data of media concentrations and other data from the literature. A multi-pathway human exposure model by USEPA was employed to calculate the populations´ Chronic Daily Intake (CDI) of PAHs. The results showed that the CDI of child, adolescent and adult were 2.92, 2.33 and 1.90 mg/(kg·d), respectively. The population´s lifelong CDI in terms of weighted age was 2.06 mg/(kg·d). Diet exposure was the most important route, accounting for around 94% of the total dose, followed by respiration and skin routes which respectively contributed 5% and 1%. Lifelong CDI of six carcinogenic PAHs (PAH6) was 0.15mg/(kg·d) and the groups of child, youth and adult were 0.22, 0.16 and 0.14 mg/(kg·d), respectively. The results of Monte Carlo simulation demonstrated that exposure approximately followed normal logarithmic distribution after logarithmic transformation. The geometric mean values of exposure to adult, youth and child were 2.09, 2.61 and 2.63 mg/(kg·d).