Chemical characterisation and cytotoxic effects in A549 cells of urban-air PM10 collected in Torino, Italy.

Human type II alveolar cells (A549) were exposed to aqueous- and organic-solvent PM10 extracts to evaluate their effects on cell proliferation, proinflammatory cytokine release and cytotoxicity (assayed by lactate dehydrogenase, LDH, activity). PM10 samples collected in Torino (northwest Italy) were analysed for inorganic chemical species (bioavailable iron and secondary particulates) and endotoxins, which are potentially inflammatory promoters in human airways. During the sampling period, PM10 concentration was 55.4±39.1 microg/m3, secondary particles constituted 42±9% of the PM10 total mass, and bioavailable iron concentration was 0.078±0.095microg/m3. PM10 inhibits cell proliferation and induces both IL-6 and LDHrelease in a dose- and time-dependent manner, with a seasonal trend. The different effects of aqueous and organic PM10 extracts demonstrate the importance of particle composition for the induction of cytotoxic effects on A549 cells. Afirst comparison between the biological effects induced byPM10extracts and PM10 components was performed.