MUTAGENICITY/GENOTOXICITY OF PM0.5 COLLECTED DURING WINTER 2014-2015 IN FIVE ITALIAN CITIES: MAPEC (MONITORING AIR POLLUTION EFFECTS ON CHILDREN FOR SUPPORTING PUBLIC HEALTH POLICY) STUDY

In the recent literature there has been an increased interest in the effects of particulate matter (PM) air pollution on health. The objective of the MAPEC (Monitoring Air Pollutions Effects on Children for supporting public health policy) study is to evaluate the associations between the concentrations of urban air pollutants and biomarkers of early biological effect in oral mucosa of 1,000 children recruited from first grade schools of 5 Italian towns (Brescia, Torino, Pisa, Perugia and Lecce) characterized by different PM levels. Child exposure to urban air pollution was evaluated by collecting ultra-fine PM (PM0.5) samples in the school areas on the same day of biological sampling. PM0.5 organic extracts were chemically analyzed (PAH, Nitro-PAH) and tested on human pulmonary A549 cell line by comet assay and micronuclei test and on Salmonella (TA100, TA98, TA98NR and YG1021 strains) by Ames test. Chemical analysis showed that PM0.5 varied significantly among the five considered towns, with different percentage contribution to PM10 (range 19.6-63%). The results of Ames test showed that all PM0.5 extracts induced indirect mutagenic effects in TA98 strain (net revertant/m3 range 0.3-1.5) while lower effect was observed with TA100 strain. Ames test with TA98NR and YG1021 strains showed the presence of nitroaromatic compounds. Except for some sporadic samples, no genotoxic or oxidative effect induced by PM0.5 extracts was demonstrated using comet assay and micronuclei test. These results could be explained by low level of air pollution observed in this winter sampling (2014-2015) and suggest further studies on biological effects of PM fractions, in particular, of the finest fraction of PM.