Effects of 24 h exposure to urine organic extract evaluated by comet and micronucleus assay performed on HepG2 cells. A) The bars are related to the means ± SD values of percent DNA tail obtained by comet assay. B) The bars are related to means ± SD values of MNi/1000 BNed obtained by Micronucleus assay. For comet assay, nine experiments were performed. For micronucleus assay, five experiments were performed. For both assays and in each experiment, B(a)P 40 μM and DMSO 1% final concentrations were the positive and negative controls; respectively. *Statistically significant (P < 0.001) compared to office workers. BNed, Binucleated cells MNi, micronuclei.