Evaluation of DNA Damage Induction and Repair Inhibition in Welders Exposed to Hexavalent Chromium

The soluble hexavalent chromium Cr (VI) used in industrial welding is an environmental contaminant widelyrecognized to act as a carcinogen, mutagen and teratogen towards humans and animals. The carcinogenic potentialof metals is a major issue in defining human health risk from exposure. In the present investigation, 93 weldersand 60control subjects with similar mean ages, smoking prevalences and alcohol consumption were enrolled forDNA damage analysis in blood leucocytes by Micronucleus assay (MN) and the Comet assay. DNA repair inhibitionwas also analyzed by assessing XPD gene polymorphism. Welders showed a significant increase in micronucleatedcells compared to controls with respect to their smoking habits and alcohol consumption, age and years ofexposure (P<0.05). Results indicated that the welders had a larger mean comet tail length than that of thecontrols (P<0.05). The current study suggested that chronic occupational exposure to Cr (VI) during weldingcould lead to increased levels of DNA damage and repair inhibition.