Characterisation of the correlations between oxidative potential and in vitro biological effects of PM at three sites in the central Mediterranean.

Atmospheric particulate matter (PM) is one of the major risks for global health. The exact mechanisms of toxicity are still not completely understood leading to contrasting results when different toxicity metrics are compared. In this work, PM was collected at three sites for the determination of acellular oxidative potential (OP), intracellular oxidative stress (OSGC), cytotoxicity (MTT assay), and genotoxicity (Comet assay). The in vitro tests were done on the A549 cell line. The objective was to investigate the correlations among acellular and intracellular toxicity indicators, the variability among the sites, and how these correlations were influenced by the main sources by using PMF receptor model coupled with MLR. The OP, OSGC, and cytotoxicity were strongly influenced by combustion sources. Advection of African dust led to lower-than-average intrinsic toxicity indicators. OP and OSGC showed site-dependent correlations suggesting that acellular OP may not be fully representative of the intracellular oxidative stress at all sites and conditions. Cytotoxicity correlated with both OP and OSGC at two sites out of three and the strength of the correlation was larger with OSGC. Genotoxicity was correlated with cytotoxicity at all sites and correlated with both, OP and OSGC, at two sites out of three. Results suggest that several toxicity indicators are useful to gain a global picture of the potential health effects of PM.