In vivo assessment of the genotoxicity of PAH-contaminated soils in rats exposed by natural routes

In order to assess the genotoxicity of polycyclic aromatic hydrocarbons (PA Hs) in vivo, male laboratory rats were exposed during 4 days to a soil high ly polluted with PAHs (1200 mg.kg(-1)) obtained from a former coke-plant. A range of dilution, from 1 to 1/8 was realized with sand. Lymphocytes were sampled every day during the exposure. Injured nuclei were quantified by the technique of Comet assay after inclusion in an agarose g el, cells lysis and electrophoresis migration (modified from [1]). This study showed an optimum response after three days in fact whatever the dilution degree 95% of the nuclei were injured. The dilution range showed a dose-response relationship. Moreover, the quantity of injured nuclei depe nded on the duration of exposure. In control animals, less than 5% of the n uclei were damaged at the end of the exposure period. So the mode of exposure has shown in vivo both the bioavailability and the clastogenicity of PAHs from polluted soils. Therefore, Comet assay can be u tilized as a biomarker to evaluate the genotoxic effects of a polluted soil .