Evaluation of sister chromatid exchange and chromosomal aberration frequencies in peripheral blood lymphocytes of gasoline station attendants

Petroleum derivatives constitute a complex mixture of chemicals which contain well-known genotoxicants, such as benzene. Thus, chronic occupational exposure to such derivatives may be considered to possess genotoxic risk. In the present study, frequencies of sister chromatid exchange (SCE); aberrant cells, including numerical and structural chromosomal aberrations; and chromosome aberrations were investigated in peripheral blood lymphocytes from 30 exposed workers (15 smokers and 15 nonsmokers) and 30 controls (15 smokers and 15 nonsmokers). The exposed subjects were employed at 12 different petrol pumping stations in the city of Mersin, Turkey. Urinary phenol levels of exposed workers were found to be significantly higher than those of control subjects. Benzene exposure and cigarette smoking decrease the replication index and mitotic index. There is an interaction between benzene exposure and cigarette smoking for replication index and mitotic index. There is no interaction between cigarette smoking and benzene exposure for chromosomal aberrations. The results indicate that there are significant differences in SCE values in the exposed workers compared to the control individuals (P<0.01), but there is no difference between smokers and nonsmokers for SCE frequency (P>0.05). SCE frequency is higher in smokers than in nonsmokers.