Atmospheric PM 2.5 -bound polycyclic aromatic hydrocarbons in China's four cities: Characterization, risk assessment, and epithelial-to-mesenchymal transition induced by PM 2.5

The chemical composition of particulate matter (PM) in urban area is prominent for the human health and generally takes a clear regional difference character. Among the complex components of PM, polycyclic aromatic hydrocarbons (PAHs) are deserved to be specifically investigated from the reason of their high carcinogenic ability. In this study, PM 2.5 samples were collected from Taiyuan, Beijing, Hangzhou, and Guangzhou in four seasons, and the concentrations of 18 PAHs were measured and analyzed. The results indicated that PAHs concentrations were significantly higher in PM from Taiyuan and Beijing than those from Hangzhou and Guangzhou. According to the health risk assessment using incremental lifetime cancer risk (ILCR) model, the cancer risk of PAHs of PM from Taiyuan was the highest, and the risk values of PAHs of PM in winter of four cities exceeded the WHO health-based guideline value. In vitro experiments indicated that winter PM 2.5 from four cities induced varying degrees of migration and invasion in A549 cells. In vivo experiments indicated that winter PM 2.5 from four cities triggered altered expressions of Epithelial-to-mesenchymal Transition (EMT) markers in C57BL/6 mice.