Chemical analysis, mutagenicity and genotoxicity of PM0.5 collected in Perugia (Italy)

Particulate matter (PM) air pollution has long been recognized as a threat to human health, causing both short and long term adverse effects. Several components of ultra-fine PM, such as polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (nitro-PAHs), have been identified as being of greatest concern for their toxic effects in humans. The aim of this work, which is part of the MAPEC_LIFE (Monitoring Air Pollution Effects on Children for supporting public health policy) study, was to evaluate the toxicity of PAHs and nitro-PAHs in ultra-fine air particulates (PM0.5) collected in four different areas in Perugia (Italy), during two different seasons (winter 2014 and spring 2015). PM0.5 was collected on glass fibre membranes using a high-volume air sampler. After 72 hours, the membranes were subjected to chemical analysis to measure the concentration of PAHs and nitro-PAHs. PM0.5 organic extracts were analysed for their ability to cause mutagenicity on four different S. typhimurium strains (Ames test) and genotoxicity in a lung adenocarcinoma (A549) cell line (comet assay and micronucleus test). Chemical analysis showed that PM0.5, PAHs and nitro-PAHs levels were higher in winter samples than in the spring ones. PM0.5 organic extracts showed mutagenic effects only in the YG1024 strain, with an increased activity when the S9 fraction was used, thus indicating the presence of promutagenic chemicals. No genotoxicity was observed in A549 cells following exposure to PM0.5 extracts collected in winter and spring, as assessed by the comet assay and the micronucleus test