Effects of Benzene on Blood System and DNA Oxidative Damage in Mice

Objective To observe the changes of peripheral hemogram, urinary S-phenylmercapturic acid (SPMA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in mice as indicators of blood system and DNA oxidative damage after benzene inhalation.

Methods A total of 120 Kunming male mice were exposed to 0, 375, 750, and 1 500 mg/m³ of benzene for 2 h each day, 5 days each week, in static inhalation cabin for three months. In each group ten mice were randomly sacrificed every month. Hemogram and urinary SPMA and 8-OHdG were measured.

Results With higher benzene exposure dose, the counts of white blood cells (WBC), red blood cells (RBC), and lymphocytes were reduced (P < 0.05), but the levels of SPMA and 8-OHdG in urine were increased (P < 0.05). Higher urinary 8-OHdG level was found in the mice with three months of 1 500 mg/m³ benzene inhalation than those with one or two months of exposure (P < 0.05). Urinary SPMA and 8-OHdG were negatively correlated with WBC (r_SPMA=-0.718, r_8-OHdG=-0.971, P < 0.01).

Conclusion Subchronic exposure to benzene might induce blood system and DNA oxidative damage in mice.