OXIDATIVE STRESS AND GENOTOXICITY AMONG WORKERS EXPOSED TO COPPER IN A FACTORY FOR NON-FERROUS INDUSTRY IN EGYPT

Abstract

Introduction: Exposure to high levels of copper at the workplace results in many adverse health effects with possible genotoxicity and carcinogenicity. Aim of work: To evaluate oxidative stress and detect the extent of DNA damage among workers at a copper processing factory. Materials and methods: The studied group is composed of 36 male workers from a copper processing factory and 34 male as a control group non-exposed to copper matched for age and socioeconomic status. Total antioxidant capacity was measured for all participants as an oxidative stress parameter, and urinary 8-OHdG was assayed by ELISA. Extent of DNA damage in leucocytes was also evaluated by comet assay as a biomarker of genotoxicity. Results: In the exposed workers, mean serum copper and urinary 8-OHdG were higher when compared to controls (155.1 ± 23 versus 77.9 ± 8.5 ug/dL and 9.7 ± 5 versus 4.1 ± 1.2 ng/mg creatinine, respectively; p<0.001 in each). T-AOC measured in exposed workers was significantly lower than that of the comparison group. There was significant DNA damage in leucocytes of exposed workers compared to the control group with mean comet tail length (9.5 ± 3.7 versus 5.7 ±1.4 mm; p < 0.001). T-AOC was negatively correlated with comet tail length; r=-0.64 and 8-OHdG showed positive correlation; r=0.71 (p < 0.001 for each). Linear regression models revealed that 8-OHdG is the significant predictor of DNA damage assayed by comet test whereas smoking, work duration and age had no significant effect on DNA damage. Conclusion: copper-exposed workers are at risk of oxidative stress with consequent DNA damage and potential genotoxic effect.