Biomarkers of genotoxicity of air pollution (the AULIS project): bulky DNAadducts in subjects with moderate to low exposures to airborne polycyclic aromatic hydrocarbons and their relationship to environmental tobacco smokeand other parameters

The levels of bulky DNA adducts were measured by P-32-post-labelling in lym phocytes of 194 non-smoking students living in the city of Athens and the r egion of Halkida, Greece, once in the winter and again in the following sum mer. Personal exposures to particulate-bound polycyclic aromatic hydrocarbo ns (PAH) were significantly higher in Athens subjects during both seasons. There was hardly any diagonal radioactive zone in the pattern of DNA adduct s observed. Highest adduct levels were observed in a sub-group of subjects living in or near the Halkida Institute campus, which was located in rural surroundings with a minimal burden of urban air pollution. The remaining Ha lkida subjects had intermediate levels, while Athens subjects showed the lo west levels. This trend, which was observed over both monitoring seasons, c onsistently paralleled the variation in three markers of exposure to enviro nmental tobacco smoke (ETS), namely (i) declared times of exposure to ETS d uring the 24 h prior to blood donation, (ii) plasma cotinine levels and (ii i) chrysene/benzo[g,h,i]perylene ratios in the profile of personal PAH expo sure. Furthermore, among the Halkida campus area subjects (but not the rema ining subjects) positive correlations were observed between DNA adducts and (i) measured personal exposures to chrysene or benzo[alpha ]pyrene, (ii) t ime of declared ETS exposure and (iii) chrysene/benzo[g,h,i] perylene ratio s. These correlations suggest that, for a group suffering minimal exposure to urban air pollution, exposure to ETS was a significant determinant of th e observed DNA damage. Gender had a consistent and significant effect on ad duct levels (males having higher levels), which remained significant even a fter multiple regression analysis. Habitual consumption of roasted meat was significantly associated with an enhancement of adduct levels and the effe ct was strengthened when only individuals unexposed to ETS were taken into consideration. No significant effects were observed for other dietary param eters or factors reflecting exposure to air pollution.