Characterization and health risk assessment of PM 2.5 -bound polycyclic aromatic hydrocarbons in 5 urban cities of Zhejiang Province, China

In 2015, we measured polycyclic aromatic hydrocarbons (PAHs) in atmospheric fine particulate matter (PM 2.5 ) collected from 5 cities in Zhejiang Province. The mean toxic equivalent quotient (TEQ) values of benzo(a)pyrene (BaP) ranged between 1.2–3.1 ng/m 3 . The BaP-TEQ displayed seasonal trends, such that winter > spring and autumn > summer. During the winter, the most abundant individual PAHs were 4–6ring PAHs (84.04–91.65%). The median daily intake of atmospheric PAHs ranged between 2.0–7.4 ng/day for all populations, with seasonal trends identical to that of BaP-TEQ. The 95 th incremental lifetime cancer risk (ILCR) values induced by PM 2.5 -bound PAHs were far lower than 10 −6 for all populations. The data suggested that the pollution levels in the 5 Zhejiang Province cities were higher than the Chinese National Ambient Air Quality Standard (NAAQS). In the future, relevant measures should be taken to control atmospheric PAHs, especially 4–6 ring PAHs. The data also revealed no obvious cancer risk for populations residing in these 5 cities of Zhejiang Province.