Investigation of cytotoxic effects of water-soluble components in PM2.5 on human primary cells derived from multiple organs

Fine particulate matter (PM2.5) contains a substantial proportion of water-soluble components. In this study, we investigated the relationship between the cytotoxicity of water-soluble extracts from 62 p.m.2.5 samples collected over one year and ambient air pollution characteristics. Results reveal the highest correlation with PM2.5 mass concentrations, followed by notable associations with ammonium, nitrate, elemental carbon (EC), organic carbon (OC), and total fatty acids (FAs). To further examine cell type–specific responses, cytotoxicity was assessed in six types of human primary cells derived from different parts of the human body, using water-soluble extracts from PM2.5 samples collected in January 2018 (a period of high pollution) and December 2018 (a period of low pollution). All six types of cells exhibited logarithmic variations in response to PM2.5 and dicarboxylic acids (DCAs), representative water-soluble secondary organics. Notably, microatglia cells and lung fibroblasts exhibited the highest sensitivity to cellular toxicity in correlation with concentrations of both PM2.5 mass and DCAs. To the best of our knowledge, this study represents one of the first attempts at assessing cytotoxicity using a larger number of actual ambient samples, particularly exploring seasonal variations in PM2.5 samples.