title: Association of the NQO1, MPO, and XRCC1 polymorphisms and chromosome damage among workers at a petroleum refinery.
abstract: Benzene is a leukemogen, and exposure to benzene is an occupational hazard in the petroleum refining industries. The effects of genetic polymorphisms in the NQO1 (rs1800566), MPO (rs2333227), and XRCC1 (rs25487) genes on benzene-induced chromosome abnormalities were assessed in 108 benzene-exposed workers and 33 office workers. The mean benzene exposure for exposed workers was 0.51 ppm for full-shift workers, and the time-weighted average ranged from 0.004 to 4.25 ppm. The frequencies of micronuclei (MN) and chromosome aberrations (CA) were significantly higher in workers exposed to benzene than unexposed controls. Exposed workers with the T/T genotype for NQO1 showed significant 1.9-fold (95% CI = 1.5-2.3) and 2.6-fold (95% CI = 1.7-3.9) increases in MN and CA frequencies, respectively, compared to controls with C/C and C/T genotypes, after adjusting for age, smoking status, and alcohol intake. Among exposed workers, subjects with the combination of MPO G/G and XRCC1 Arg/Gln or Gln/Gln showed a significantly higher CA frequency compared to those with the combination of MPO G/A or A/A and XRCC1 Arg/Arg genotypes. These results indicated that the genotoxicity induced by a chronic benzene exposure is modulated by genes involved in both DNA repair and benzene metabolic pathways.
authors.affiliation: School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Korea.
authors.forename: Yang Jee
authors.initials: YJ
authors.lastname: Kim
authors.forename: Jun Yeol
authors.initials: JY
authors.lastname: Choi
authors.forename: Domyung
authors.initials: D
authors.lastname: Paek
authors.forename: Hai Won
authors.initials: HW
authors.lastname: Chung
mesh_terms: D000328:Adult; D001554:Benzene / Q000378:metabolism / Q000633:toxicity*; D016022:Case-Control Studies; D004260:DNA Repair / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D008875:Middle Aged; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics*; D016273:Occupational Exposure / Q000009:adverse effects*; D009195:Peroxidase / Q000235:genetics*; D010578:Petroleum; D020641:Polymorphism, Single Nucleotide; D012997:Solvents / Q000378:metabolism / Q000633:toxicity*; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D010578:Petroleum; D012997:Solvents; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; D009195:Peroxidase; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; D001554:Benzene