Abstract

Background and objective: Bioindicators of drinking water are always influenced by physical and chemical factors such as turbidity and chlorine.  Considering the assessment of drinking water quality is based on residual chlorine, E.coli, heterotrophic bacteria and turbidity.  We aimed to evaluate the effect of pH, chlorine residual and turbidity on the microbial bioindicators.

Material and methods: In this descriptive-analytic study, 324 and 32 water samples were collected from rural and urban water distribution network of Aq Qala city in 2013, respectively. All steps were performed according to standard methods.

Results: In rural water supply, 5%, 9% and 33% of the samples were contaminated with fecal coliform, fecal streptococcus and the heterotrophic more than 500CFU / ml. In urban network, coliform contamination was not seen and other bioindicators were less than those of rural networks were. Turbidity of above 5 NTU in urban and rural samples was 3 and 9 percent, respectively. Bioindicators had significant relationship with residual chlorine, fecal coliform bacteria with pH and turbidity with heterotrophic bacteria (P ≤0.05).

Conclusion: The presence of fecal streptococcus bacteria in some samples without fecal coliform cannot confirm the safety of drinking water.  Microbial contamination in the presence of residual chlorine implies that just chlorination   is not enough for having healthy water.

Keywords: Chlorine, Turbidity, Biological Factors, Drinking water

Abstract

Background and Objective: Swimming pools, which are recreational places, can cause transmission of bacterial diseases, fungal and parasitic infections due to direct contact with various groups of people. We aimed to determine and compare the common microbial indicators in the water of pools and Jacuzzis in Golestan province.

 Material and Methods: the samples were obtained from eight indoor pool and Jacuzzi in Golestan province from July to December 2010, to evaluate the biological and physiochemical parameters.

Results: The residual chlorine in the pool and Jacuzzis was 74.3 % and the 41.1 %, respectively, and the difference was significant; the pH level was 70.4 % and 78.1 %, respectively; the mean of turbidity was 17.8 %, and 9.8 % and the difference was not significant. The samples contaminated with total coliform in the pool and Jacuzzi, respectively, were 4.3 % and 15.2 % and with E. coli were 1.3 % and 11.2 %.

Conclusions: The higher contamination of Jacuzzi is related to the higher temperature and turbidity of water, and more exposure of swimmer with water and less recirculation of Jacuzzi water. The high turbidity, lack of desired residual chlorine and choliform contamination are the main problems of swimming pools and Jacuzzi in Golestan province.

Keywords: Biological indicators, Microbial, Pool, Golestan Province.