Detection of Sperm DNA Damage in Workers Exposed to Benzene by Modified Single Cell Gel Electrophoresis

Objective To assess the effect of benzene on sperm DNA damage Methods Twenty-seven benzene-exposed workers were selected as exposed group and 35 normal sperm donors as control group. Air concentration of benzene series in workshop was determined by gas chromatography. As an internal exposure dose of benzene, the concentration of trans, trans-muconic acid (ttMA) was determined by high performance liquid chromatography. DNA was detected by modified single cell gel electrophoresis (SCGE). Results The air concentrations of benzene, toluene and xylene at the workplace were 86.49 ± 2.83 mg/m3, 97.20 ± 3.52 mg/m3 and 97.45 ± 2.10 mg/m3, respectively. Urinary ttMA in exposed group (1.040 ± 0.617 mg/L) was significantly higher than that of control group (0.819 ± 0.157 mg/L). The percentage of head DNA, determined by modified SCGE method, significantly decreased in the exposed group (n=13, 70.18% ± 7.36%) compared with the control (n=16, 90.62% ± 2.94%)( P<0.001). Conclusion The modified SCGE method can be used to investigate the damage of sperm DNA. As genotoxin and reprotoxins, benzene had direct effect on the germ cells during the spermatogenesiss.