Busting a Chlorine Swimming Pool Urban Myth

The Water Quality and Health Council would like to thank John Tesh for tweeting the results of our swimmer hygiene survey and for giving us an opportunity to address a very common urban myth.

Last week, musician, composer and radio talk show host John Tesh tweeted the finding from a recent Water Quality & Health Council survey that one in five swimmers admit to “peeing in the pool”. Tesh warns, “If you smell chlorine, stay out”.  I appreciate the fact that Tesh raised this subject and respectfully submit that his tweet needs a tiny tweak.

A healthy chlorinated pool can emit a light chemical odor, especially if it is an indoor pool and one with less than ideal ventilation. It is good advice, however, to stay out of the water when a strong chemical smell pervades the air around any type of pool, indoor or outdoor. On this point John Tesh is absolutely correct.

What actually causes the distinctive, irritating smell around swimming pools is not chlorine–that’s an urban myth–but volatile substances known as chloramines.  Chloramines form in pool water when chlorine combines with contaminants brought into the pool by swimmers.  Think urine, perspiration, body oils and cosmetics.  The truth is that cleaner swimming, not less chlorine, can help reduce the chloramine irritants that cause “swimmer red eye” and itchy skin. The Centers for Disease Control and Prevention’s swimmer hygiene tips recommend swimmers shower with soap before entering the pool (almost 70% of the survey respondents said they don’t do this routinely) and stop peeing in the pool.

The next sentence of Tesh’s tweet requires no tweaking at all:  The smell gets stronger if there’s urine in the water.  It is true that the more urine there is to combine with chlorine, the higher the level of unwanted, smelly chloramines in the pool.  Following that thread, if chlorine is combining chemically with contaminants like urine, then it is not available to destroy germs in the pool that can make swimmers sick with diarrhea, swimmer’s ear and various skin infections.

Eighty-seven percent of respondents to the survey agreed with the urban myth that it is chlorine in pool water that makes swimmers’ eyes red and irritated.  Ironically, the irritants actually responsible, chloramines, may be produced when there is not enough chlorine in the pool.  The bottom line:  Pool operators need to keep pool chemicals in appropriate ranges.  Swimmers need to clean up their act.  The proof will be in the air around the pool.

Swimmers can order free pool test kits from the Water Quality & Health Council to see if their pool pH and free chlorine levels are in the proper range.

Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.