The impact of organic extracts of seasonal PM on primary human lung epithelial cells and their chemical characterization.

Lung epithelial cells serve as the first line of defense against various inhaled pollutant particles. To investigate the adverse health effects of organic components of fine particulate matter (PM) collected in Seoul, South Korea, we selected 12 PM samples from May 2016 to January 2017 and evaluated the effects of organic compounds of PM on inflammation, cellular aging, and macroautophagy in human lung epithelial cells isolated directly from healthy donors. Organic extracts of PM specifically induced neutrophilic chemokine and interleukin-8 expression via extracellular signal-regulated kinase activation. Moreover, PM significantly increased the expression of aging markers (p16, p21, and p27) and activated macroautophagy. Average mass concentrations of organic and elemental carbon had no significant correlations with PM effects. However, polycyclic aromatic hydrocarbons and n-alkanes were the most relevant components of PM that correlated with neutrophilic inflammation. Vegetative detritus and residential bituminous coal combustion sources strongly correlated with neutrophilic inflammation, aging, and macroautophagy activation. These data suggest that the chemical composition of PM is important for determining the adverse health effects of PM. Our study provides encouraging evidence to regulate the harmful components of PM in Seoul.