Effects of ambient PM_2.5 collected using cyclonic separator from Asian cities on human airway epithelial cells

Recent studies have shown that air pollution is intense and hazardous in Asia compared to other parts of the world due to the late and poor implementation of updated technology in automobiles and industry as well as to the high population density. Respiratory disease, including asthma, is exacerbated by air pollution. However, the effects of PM_2.5, especially on respiratory allergies in Asian cities, have not yet been examined in detail. In this study, airway epithelial cells were exposed to crude PM_2.5 particles collected by cyclonic separation from three different Asian cities, namely, Sakai, Bangkok, and Taipei. We compared the cytotoxicity and inflammatory potential of the PM_2.5 from these cities by measuring IL-6 and IL-8. The samples from Sakai and Bangkok caused cytotoxic effects at a dose of 75 µg mL^–1 and, moreover, induced the release of IL-6 and IL-8 even at low doses. The release of these two interleukins was highly associated with fluoranthene derivatives, microbial factors (endotoxin and β-glucan), metals (e.g., Ti), and organic (OC2 and OC3) and elemental carbon (EC1) in the PM_2.5. Thus, these components potentially contribute to cellular damage and a pro-inflammatory response in the airway epithelial cells, and the effect depends on PM_2.5 sources in the locations.