Background:Among safe recreation, use of pools are becoming more popular. Due to health issues and ways to ensure the health and welfare of people, swimming pools are very important. The major health issues in this field is attention to water quality. Also Immersion in water may cause water to inter the mouth, nose, ear and eye. Thus, in the case of water pollution related deaseses will be acure. Sanitary control of swimming pools is necessary to maintain siwimmer health and prevent swimmer from deasese.Thus The need for research in this area seems necessary.

Methods:This study, based on applied research and analytical - descriptive, correlational, cross-sectional survey was conducted. In this project, we studied 35 swimming pools in the city of Karaj. For this purpose, samples were collected every month for 9 months, turbidity, pH, free residual chlorine measuring was cundacted at the sampling time and testing for total coliform, E.coli coliform and counting of hetrotrophic organisms in the laboratory of water and wastewater was performed. data analyzed by using Excel and SPSS software.

Results:The results showed a total of 315 analysed the measuring parameters chlorine, pH, turbidity , respectively were 88.9 percent, 90.8 and 100 percent in standard range and 9.2 %, 11.1 non-standard were reported, and the negative total coliform and heterotrophic were reported 95% and 99% respectively. Based on statistical analysis, no significant correlation was obtained between microbial contaminations by residual chlorine.

Conclusion:The results showed swimming pools were in appropriate health status. The control of risk factors and pay attention to hygiene standards by swimmers and pool staff are good strategy for pollution control.