Chromosomal damage and polymorphisms of DNA repair genes XRCC1 and XRCC3 in workers exposed to chromium.

OBJECTIVES: Welders, chronically exposed to hexavalent chromium, may exhibit disturbances in chromosomal integrity. Our study investigates chromosomal damage related to chromium exposure, considering the role of polymorphisms in relevant DNA repair genes.

METHODS: 39 male welders exposed to chromium for 10.2+/-1.67 years and 31 male controls were assayed for structural chromosomal aberrations (conventional cytogenetic analysis). DNA repair gene polymorphisms were determined by Real-Time allelic discrimination assay.

RESULTS: Total chromosomal aberrations were moderately, but statistically not significant, higher in exposed individuals (1.96%) than in controls (1.55%). Chromosomal type breaks were almost two-fold higher in exposed than in control individuals. The highest frequency of total chromosomal aberrations was recorded in individuals with homozygous variant Gln/Gln cariers (2.14%) in XRCC1* Arg-399Gln and the lowest in those with the wild-type Arg/Arg cariers (1.33%). Polymorphisms in XRCC3 gene did not modulate the frequencies of CAs, CTAs and CSAs.

CONCLUSIONS: Understanding the effects of chromium on chromosomal integrity in relation to individual susceptibility may be a basis for preventive measures in working process.