The oocysts were stained with immunofluorescent dye and the particles enumerated microscopically according to ASTM Method P229. The results of this study are presented in Table 1. The data obtained by Analytical Services indicate an average log removal of 3.3 for these cartridges. This is comparable to the log removal requirement of greater than 3.5 in NSF Standard 53. Conclusion Pathogenic Cryptosporidium cysts represent a health hazard that does not respond to routine chlorine treatment.
Filtration is the most reliable and economic remedy available to the bottled water industry.
Because cysts are not killed by conventional chemical treatment, hot water or steam is required to disinfect filters and process equipment. Live cyst testing shows that the live cyst removal rate is on par with the particle log removal rate specified in NSF Standard 53. December 1993 2. American Public Health Association Washington DC 20005 4.