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Release: Immediate

UI researchers say disease risk from swimming pools is small, yet still a concern

IOWA CITY, Iowa -- As summer approaches, University of Iowa microbiologists will be working to insure that public swimming pools are properly operated and free of contamination.

Dr. Nelson Moyer, principal microbiologist at the UI Hygienic Laboratory, and his staff examine water samples for traces of coliform bacteria and pseudomonads, indicators of contamination in swimming pools and whirlpools. Diseases such as cryptosporidiousis, which causes diarrhea, and pseudomonas foliculitis, which causes an itchy rash along the swimsuit line, are typical of the diseases acquired in pools.

Whirlpools, or hot tubs, have the most potential for contamination due to their high water temperatures. "Bacteria thrives in warm temperatures," Moyer says. "If not properly maintained, whirlpools can be a haven for bacteria." When whirlpools became popular during the 1980s, outbreaks of pseudomonas were prevalent. While the maintenance of public whirlpools has become regulated, outbreaks today tend to occur in private homes, where maintenance is not regulated.

Dr. Nancy Hall, public health microbiologist at the UI Hygienic Laboratory, suggests several steps to prevent recreational pool contamination. "Pool operators need to monitor pH levels, make sure their filtration systems are properly functioning and keep proper disinfection levels at all times," she says.

While pool operators bear the majority of the responsibility, swimmers also need to take precautions. "Even though many people tend to ignore this caution, it is very important to bathe before you swim to prevent pool contamination," Hall says.

While testing for contamination in pools is very important, Moyer says that swimming pool outbreaks are rare in Iowa. "State laws require pool operators to carefully monitor pool operation and maintenance," Moyer says. "Through proper care and disinfection, the number of diseases contracted through pools are very small."