In vitro evaluation of genotoxicity and methylation changes induced by particulate matter from the Padana Plain

Particulate matter (PM) is a major air pollutant with significant health impacts. Studies show that PM induces various cellular effects, including cytotoxicity, mutagenicity, and genotoxicity, and its epigenetic alterations are linked to increased disease susceptibility and progression. As epigenotoxic effects of xenobiotics are increasingly recognised, it is crucial to adopt approaches beyond genotoxicological analysis to assess PM impact on the epigenome. This study evaluated the genotoxicity of PM extracts from five monitoring sites (urban, traffic, incinerator, and two rural sites) using the comet assay on BEAS-2B cells. The highest pollutant concentrations were observed in autumn-winter and, in the same months, the Ames test showed maximum mutagenic activity. The comet assay confirmed this trend, revealing greater DNA damage at the traffic site in winter and autumn, and significant damage at the incinerator and urban sites during the cold months, aligning with Ames test results. Additionally, a methylation-sensitive comet assay was applied to assess DNA methylation changes induced by PM. The strongest epigenetic effects were observed in PM samples from winter and autumn, suggesting that higher concentrations of PAHs or other pollutants during these seasons contribute to these effects. The varying epigenetic outcomes highlight how PM composition-both type and quantity-can influence biological effects. This modified in vitro version of comet assay demonstrated its utility in monitoring both genotoxic and epigenetic effects of PM, providing a comprehensive tool for assessing its biological impacts.