Mutagenicity of PM2.5 ☆

PM2.5 pollution is one of the most important concerns involved in the evaluation of the health effects of air pollution. The mutagenic activity of ambient outdoor air has been widely reviewed in the literature; however, only during the last 15 years there are data specifically regarding PM2.5. The mutagenic properties of fine PM are generally higher than those of coarse PM. Moreover, the ultrafine particles (UFPs) contribution to the total PM mutagenicity is the highest. PM2.5 organic extracts are generally mutagenic, especially in winter, in urban environments, or in proximity to the chief emission sources of air pollutants. Combustion reactions and the atmospheric reactions of gaseous pollutants with hydrocarbons result in a large number of dispersed DNA-reactive compounds. Biological assays could indicate both genotoxicity and mutagenicity tests. The last are assays able to simulate the effects of the complex environmental mixture on a biological system and might indicate the ability of known or unknown compounds in a mixture to interact with DNA-producing mutation processes. This approach is useful in a screening evaluation of the genotoxic and cancer risk associated with air pollution. The accumulated data supported the evaluations of the global genotoxic burden for urban populations and could promote precautionary measures taken to reduce environmental pollution. Today the PM2.5 limits seem to be not enough cautionary for the public health. Future studies need to be carried out on specific PM2.5 sources and specific chemical compounds endorsed to the particles and on the UFPs that are responsible for most of the mutagenic effects. The application of different biological assays may support and complete Salmonella assay results as well as supply biological evidence that helps to elucidate carcinogenic pathways.