Impact of after-treatment devices and biofuels on diesel exhausts genotoxicity in A549 cells exposed at air-liquid interface.

Using an air-liquid interface (ALI) device in dynamic conditions, we evaluated the efficiency of fuel after-treatment strategies (diesel oxidation catalysis, DOC, and diesel particulate filter, DPF, devices) and the impact of 7% and 30% rapeseed methyl esters (RME) blending on oxidative stress and genotoxicity induced in A549 lung cells after 3h exposure to whole Diesel exhausts. Oxidative stress was studied using assays of ROS production, glutathione level, catalase and superoxide-dismutase (SOD) activities. No oxidative stress and no clear differences on cytotoxicity patterns between biodiesel and standard Diesel exhausts were found. A weak but significant genotoxicity (8-oxodGuo adducts) and, for standard Diesel only, a DNA damage response (DDR) as evidenced by ƔH2AX foci, remained after DOC+DPF flowing. All together, these data could contribute to the improvement of the after treatment strategies and to health risk assessment of current diesel exhausts.