But not in a good way. The studies suggest that some of the chemicals used to disinfect indoor pools generate other chemicals that in turn may induce short-term respiratory effects and something called genotoxicity — damage to the DNA in cells. DNA damage can, of course, lead to cancer.
But don’t jump out of the pool — yet. As reporter Janet Raloff points out in her thorough review of the studies’ findings for Science News, the rates of DNA mutations in the 49 swimmers who participated in the research were low and might even be repaired by the body’s natural repair mechanisms.
The researchers identified, for the first time, about 100 different disinfection byproducts associated with pool water. (Only five had been known previously.) But, again, don’t panic. That number is nothing like the 600 known byproducts associated with the disinfection of drinking water.
“Once you start putting people in the water along with suntan oils and air-blown debris, you’re going to find disinfection byproducts,” a chemist told Raloff. The fact that pool water is being found to be no more mutagenic than drinking water is “fabulous,” he added.
The biggest sources of DNA-damaging byproducts in pool water are, apparently, skin, sweat and urine. “Swimmers need to be more aware of their personal hygiene,” another expert told Raloff. Taking a shower before you jump into the water helps enormously to improve everybody’s health. As does, ahem, taking bathroom breaks. “The urea in urine reacts with chlorine to produce some of these disinfection byproducts,” the expert explained. “In fact, it’s the constituents of human sweat and urine that are largely responsible for their formation.”
Why anybody over the age of 10 needs to be reminded to take bathroom breaks during swimming sessions is beyond me. But, then, earlier this year, in a journal article subtitled “Can we have both healthy pools and healthy people?” these same researchers felt it necessary to admonish the American public to “get past its acceptance of poor pool hygiene.” We have a culture, they wrote, “that seems to humorously ‘celebrate’ using the pool as a urinal. There is ample anecdotal evidence that young children and young adults on swim teams are discouraged from taking bathroom breaks during training. … Public education is needed regarding the immediate reporting of fecal incidents to pool operators and refraining from swimming while ill or while recovering from diarrheal illness.”
OK, now you can jump out of the pool.