Comparison of DNA damages in blood lymphocytes of indoor swimming pool lifeguards with non-lifeguards athletes

•DNA damage is more in lifeguards than in the control group.•DNA damage was significantly higher in female lifeguards in comparison with males.•Long term exposure to Chlorine in indoor pools increases the DNA damage. Chlorination has been used as a major disinfectant process for swimming pool water in many countries. The purpose of this study is to compare the DNA damage of the blood lymphocytes in indoor pool lifeguards with non-lifeguards athletes. We performed a study in which the participants were Gonabad’s lifeguards. We chose 30 participants (15 male and 15 female) for each group. We collected vein blood samples from each participant in both exposed and control group. The lymphocytes were isolated from the whole blood by ficoll, and the cell viability was determined by the trypan blue. The alkaline Comet assay was also performed on lymphocytes in order to measure the DNA damage. All the parameters indicated that the DNA damage was significantly greater in lifeguards group than control group (p