Investigating the relationship between free chlorine concentration and heterotrophs in water of swimming pool in Iran.

Swimming pools rank high among dangerous places for human recreation, which play an important role due to the high number of references and require continuous monitoring of pollutants and factors affecting it. Therefore, this study was conducted with the aim of systematically investigating the relationship between chlorine and heterotrophs in published studies in Iran. PubMed, Science Direct, and Google Scholar databases were searched from April 2000 to September 2022. Then identified studies were evaluated, then the studies lacking the necessary quality were excluded. From 686 articles, 33 reputable studied investigated the concentration of free chlorine in Iranian pool water. However, 14 studies measured the free chlorine and heterotrophs in swimming pools of 12 different Iranian cities. According to the results of the present study, the appropriate residual chlorine has reduced the microbial contamination of the pools, also, using the clarification in conjunction with the remaining free chlorine concentration, can help ensure the bacteriological quality of the water in the swimming pool. So maintaining the residual chlorine levels and daily cleaning of the pool can be effective in controlling heterotrophs in swimming pools and water recreational environments.