Abstract
Lead is a non-biodegradable and significant environmental chemical contaminant. Lead decreases the accuracy of DNA synthesis or repairs and inhibits the activity of DNA polymerase, thus it causes DNA damage including DNA base modifications, DNA strand breaks, chromosome rearrangements. Comet assay is a recently developed technique in order to monitor human populations that have been exposed to environmental toxicants. The aim of this study was to investigate the association between the DNA damage and lead levels in individuals who are exposed to lead due to occupational reasons. For this purpose, 61 workers exposed to lead were monitored in the way of DNA damage in blood lymphocytes. The levels of DNA damage were measured according to three comet assay parameters including tail intensity (TI), tail moment (TM) and DNA tail (DNAt) by BAB Bs Comet Assay system and Pb levels were analyzed with the atomic absorption spectrometer system. As a result, statistically significant positive correlation was found between the Pb levels and TI, TM and DNAt parameters (r=0.515, p<0.01; r=0.507, p<0.01; r=0.343, p<0.01, respectively) in peripheral lymphocytes. Smoking had independent effects on TI, DNAt and TM. Significant difference was observed between the smokers and non-smokers in relation to DNA damage parameters (p<0.05). In addition, when the Pb levels were compared with smokers and non-smokers groups, Pb levels in smokers were found significantly higher than non-smokers (17.96±13.27 ppb versus 4.77±2.47 ppb; p<0.05). In summary, our results show that exposure to Pb induces genotoxic effect in peripheral lymphocytes, as measured by comet assay.
