microbiological and some chemical appraisal of outdoor public swimming pools in tehran, iran

in order to determine the hygiene indices of bathing water, and it's water quality, a survey and laboratory analysis was recently undertaken on 34 outdoor public swimming pools out of a total 126 in tehran metropolitan area according to simple random sampling without replacement. this survey revealed remarkable evidence of waver bacterial contamination at heavy bather load time. examined water samples from pools failed to show the presence of any common enteric viruses, but bacteria especially pseudeomonas aeruginosa, staphylococcus aureus and e.coli were isolated from 76, 21 and 35 percent of samples respectively. bacterial indices of 1100 faecal coliform by mpn were detected in 21 percent out of cases, results were obtained when the residual chlorine content of the pool ranged from 0.05 to zero ppm. 21 percent out of the total public swimming pools under the study do not use any disinfecting agents and nine pools did not use any treatment. chemical analyses of swimming pools indicated obvious degree of pollution, for instance residual chlorine level ranged from zero to 0.6 ppm while ammonia nitrogen ranged from 0.12 to 1.32 ppm as n and chloride ranged from 25 to 430 ppm as cl- .