Micronucleus occurrence in Chinese workers occupationally exposed to benzene

Objective. To assess chromosomal damage, investigate its risk factors, and explore its association with white blood cell (WBC) decrease among benzene-exposed workers. Methods. A total of 312 subjects including 219 benzene-exposed workers and 93 unexposed controls were recruited, and the exposed subjects were classified according to WBC count as low, unstable and normal WBC group. Chromosomal damage in peripheral blood samples were evaluated using cytokinesis-blocked micronucleus (CBMN) assay. Statistical analysis was performed using chi(2) test and Poisson regression model. Results. The micronucleus (MN) frequencies in the low WBC group (2.75+/-1.95)%, unstable WBC group (2.49+/-1.85)% and normal WBC group (2.02+/-1.63)% were all higher values than the control group (1.22+/-1.12)% based on simple Poisson regression (P<0.01). Low and unstable WBC group has a higher average MN frequency than normal WBC group, too. Moreover, with the decrease of WBC count, there is a trend of increased MN abnormality rate among all exposed groups. Conclusion. Chromosomal damage induced by low-level benzene exposure is related with WBC decrease and might be an early predictor of hematotoxicity/genotoxicity among the exposed population. Eur. J. Oncol., 17 (2), 71-78, 2012