Comparison of genotoxic and inflammatory effects of particles generated by wood combustion, a road simulator and collected from street and subway.

The health effects of exposure to airborne particles are of increasing concern in society. In order to protect public health, a clarification of the toxic properties of particles from different sources is of importance. The aim of this study was to investigate and compare the genotoxicity and the ability to induce inflammatory mediators of nine different particle types from wood and pellets combustion, from tire-road wear and collected from an urban street and a subway station. The comet assay was used to assess genotoxicity after exposure of the human lung cell line A549. Inflammatory effects were measured as induction of IL-6, IL-8 and TNF-alpha after exposure of human macrophages. We found that all particles tested caused DNA damage and those from the subway caused more damage than the other particles (p<0.001) likely due to redox-active iron. In contrast, particles collected from an urban street were most potent to induce inflammatory cytokines. Particles from tire-road wear collected using a road simulator were genotoxic and able to induce cytokines. Finally, more effective combustion of wood led to less emission of particles, but those emitted did not show less toxicity in this study.