Objective To investigate the genetic damage of long-term low concentrations of benzene exposure.
Methods The air concentrations of benzene at workplaces were measured and evaluated by gas chromatography.Blood routine test,chromosomal aberration,and micronucleus assays of peripheral blood lymphocyte in an exposed group (n=116) and a control group (n=62) were performed.
Results The air concentrations of benzene in the selected workplaces were <0.033-1.898 mg/m3,lowerthan the national occupational exposure limit of benzene (permissible concentration-time weighted average,PC-TWA=6 mg/m3;permissible concentration-short term exposure limit,PC-STEL=10 mg/m3).The average white blood cell (WBC) count in the exposedgroup was (4.70& #177;1.02)& #215;109/L,lower than that of the control group(6.58& #177;1.61)& #215;109/L(P<0.01),and also negativelycorrelated with length of service (r=-0.993,P<0.01).The chromosomal aberration rate and the micronucleus rate in the exposedgroup and the control group showed significant differences (P<0.05),and were positively correlated with length of service (r=0.289,0.616;P<0.01) and negatively correlated with WBC count (r=-0.306,-0.645;P<0.01).
Conclusion Long-term exposure tolow concentrations of benzene at work can cause cytogenetic damage effect in exposed workers.
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