[A association of genetic polymorphisms of XRCC1 and damage levels in workers exposed to coal tar pitch].

Objective: To study the relationship between XRCC1 gene polymorphism and DNA damage in peripheral blood lymphocytes of workers exposed to coal tar pitch. Methods: 203 coal tar asphalt device operation area workers (exposure group) and 76 logistics management personnel (control group) as the research ob-ject, determination of 1-hydroxypyrene concentrations in the urine as polycyclic aromatic hydrocarbons expo-sure dose, using the alkaline comet assay evaluation a peripheral blood lymphocyte DNA damage degree, using TaqMan MGB real time PCR method to detect XRCC1 gene 3 loci (XRCC1-194, XRCC1-280 and XRCC1-399) single nucleotide polymorphism. Results: No significant differences was observed in age, sex, smoking and alco-hol consumption between the two groups ( P >0.05). The level of 1-OHP in the exposed group was significantly higher than that in the control group (1.27±0.93 μg/g creatinine) ( P <0.05). The comet Olive tail moment level (3.21±0.93) in the peripheral blood lymphocytes of the exposed group was significantly higher than that in the control group (0.94 ± 0.39) ( P <0.05). There was no significant difference in genotype distribution of XRCC1-194, XRCC1-280 and XRCC1-399 between the two groups ( P >0.05). There was a significant correlation be-tween the XRCC1-280 locus gene polymorphism and comet Olive tail moment in the exposure group ( P <0.05) af-ter adjustment for sex, age, smoking rate, drinking rate, length of service and urinary 1-OHP concentration. The comet Olive tail moment level of GG individuals carrying wild homozygous genotype was significantly lower than that of individuals carrying heterozygous genotype GA and carrying mutant homozygous genotype AA ( P < 0.05) , and the difference was statistically significant ( P <0.05) The comet Olive tail moment level of heterozy-gous genotype GA was significantly lower than that of genotype AA with mutational homozygous genotype AA ( P <0.05) , and the difference was statistically significant ( P <0.05). Conclusion: Arg280His locus polymor-phism of XRCC1 gene may influence the DNA damage level of peripheral blood lymphocytes induced by occupational exposure to coal tar pitch.