Objective To explore the association between chromosomal damage induced by benzene mixtures and the genetic polymorphisms of metabolic enzymes CYP2E1 and NQO1.
Methods Cytokinesis-block micronucleus (CBMN) assay was used to detect chromosomal damage in peripheral lymphocytes of 461 benzene-mixture-exposed workers and 88 controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was applied to detect polymorphisms of CYP2E1 Pst and NQO1609.
Results The CBMN frequency in the exposed workers was significantly higher than that in the control group(2.12& #177;1.87)‰ vs. (1.19& #177;1.68)‰, P<0.01. The individuals with the NQO1609 CC genotype showed significantly higher CBMN frequencies than the individuals with TT genotype (P<0.05) in either single or multiple factor analysis. Age was an effect modifier for elevated CBMN frequency, while sex, smoking, and alcohol consumption had no relationship with CBMN frequencies.
Conclusion Methylbenzene or dimethylbenzene exposure is not a key contributor to genetic damages. Cytokinesisblock micronucleus can be used to detect the early genetic damage of benzene mixture-exposed workers. NQO1609 polymorphisms are associated with chromosomal damage induced by benzene mixtures.
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