[Association between XRCC1 polymorphisms and chromosome damage in workers exposed to benzene in jewelcrafting...

To investigate the association between the gene polymorphisms of the DNA damage repair gene X-ray repair cross-complementing gene 1 (XRCC1) and susceptibility to chromosome damage in workers exposed to low-concentration benzene in the jewelcrafting industry.

A total of 286 workers exposed to benzene in jewelcrafting enterprises were enrolled as study subjects from January 2013 to December 2014. Gas chromatography was used to measure benzene concentration in workplace, cytokinesis-block micronucleus test was used to analyze the level of chromosome damage in peripheral blood, and the Sequenom technique was used to determine the single nucleotide polymorphisms of XRCC1.

The time-weighted average concentration of benzene in workplace was <0.6~1.8 mg/m(3), lower than the national occupational exposure limit (6 mg/m(3)). The distribution of allele frequencies met the Hardy-Weinberg equilibrium in genetics (P>0.05). Increase in age (RR=1.38, 95%CI 1.06~3.75) and increase in working years (RR=1.45, 95%CI 1.18~2.58) were risk factors for the increase in micronucleus frequency. Compared with those with the wild-type homozygous genotype, the individuals with XRCC1 rs25487 CT genotype showed a significantly higher risk of increase in micronucleus frequency (RR=1.51, 95% CI 1.28~3.87, P<0.05) , and the individuals with XRCC1 rs1799782 AA genotype also showed a significantly higher risk of increase in micronucleus frequency (RR=1.65, 95% CI 1.30~3.12, P<0.05). There was no clear association between XRCC1 rs25489 polymorphisms and micronucleus frequency (P>0.05).

Exposure to low-concentration benzene may cause chromosome damage in workers exposed to benzene, and the XRCC1 polymorphisms rs 25487 and rs1799782 may be associated with chromosome damage induced by benzene.