ASSESSMENT OF MICROBIOLOGICAL QUALITY FOR SWIMMING POOLS IN SOUTH-AMERICA

Concerning the great importance of the safety of bathing water, and du e to the dispute about the better microbiological indicator to assess the water quality of swimming pools, 1345 samples of water collected f rom 60 swimming pools in a period of four years were analyzed for tota l (TC) and fecal coliforms (FC), fecal streptococci (FS), heterotrophi c bacteria (HPC), S. aureus (Sa), C. albicans (Ca) and P. aeruginosa ( Pa). The frequency of positive results for these indicators ranged up to 70.4% (HPC), 13.3% (TC), 9.1% (Sa), 7.7% (FS), 5.6% (FC) and 2.0% ( Pa and Ca). A correlation matrix (Spearman rank correlation) showed st rong positive relationship among the levels of these microorganisms an d between their densities and bather load and water temperature. As ex pected, all the microbiological variables presented a negative correla tion with chlorine, C. albicans showing to be the more resistant to th is disinfectant. Considering the good correlation among all these micr obiological parameters, the highest rates of isolation of heterotrophi c bacteria and total coliforms and the costs for microbiological analy sis, it is possible to achieve an effective monitoring of swimming poo l water quality by using only these two indicators, with no need of ap plying the other ones on a routine basis. P. aeruginosa and C. albican s, besides their high resistance to chlorine, presented a very low inc idence and its use for evaluating swimming pool waters quality in rout ine is not indicated.