[Influence of cigarette smoking on the excretion of urinary benzene in filling-station attendants].

The influence of cigarette smoking on concentrations of urinary benzene, a sensitive and specific biomarker proposed for biological monitoring of exposure to very low doses of benzene, was investigated in 24 filling-station attendants and 31 workers non occupationally exposed to benzene. Environmental monitoring was performed by personal passive samplers "Radiello", and a spot urine sample was collected at the end of the work shift, from all subjects, for the determination of urinary benzene. Exposure to benzene resulted significantly higher in filling-station attendants (mean 23.3 +/- 17.0 microg/m3; range 4.5-66.3 microg/m3) than in controls (mean 4.6 +/- 2.6 microg/m3; range < 3-11.5 microg/m3), while concentrations of urinary benzene did not show any significant difference between the two groups. Considering all subjects as a single group, it was observed that urinary benzene concentrations were positively correlated with the number of cigarettes smoked during the sampling time (rho = 0.38; p = 0.047) and with airborne benzene levels (rho = 0.32; p = 0.019), and negatively correlated with the time elapsed between the last smoked cigarette and urine collecting (rho = -0.40; p = 0.045). Multiple regression analysis confirmed the influence of cigarette smoking on urinary benzene concentrations. In conclusion, our study showed the validity of urinary benzene as a biomarker for biological monitoring of exposure to very low doses of benzene, although cigarette smoking determined a prevalent etiological role at the low environmental benzene concentrations observed.