There’s an Actual Scientific Reason Not to Pee in the Pool

When urine mixes with chlorine, potentially harmful substances can result

Photo: greg lilly

When kids learn to swim, lessons about diving and doggie paddling are often accompanied by stern warnings not to pee in the pool. Yet both kids and adults are guilty of this offense. This behavior needs to stop. Besides being disgusting—would you urinate on your friends if you were on land?—peeing in the pool can also create potenital health problems, new evidence shows.

According to a new study, when urine—specifically, uric acid—mixes with chlorine it can form new compounds called trichloramine and cyanogen chloride, both of which are "are ubiquitous in chlorinated, indoor swimming pools," the authors write. These compounds can cause lung problems, and the latter is also associated with some heart and nervous system problems. Although some of those comounds form from uric acid released in sweat, the researchers point out that an estimated 90 percent of uric acid in a pool originated from urine, not sweat. Here's the Record with more on the findings: 

Uric acid is linked to 24 per cent to 68 per cent of this byproduct in pool water, the scientists said.

And you can chalk up 3 per cent to 4 per cent of the harmful byproduct trichloramine in pool water to uric acid. 

Both of these gases have been linked to chronic health issues among swimmers.

Until now, no one had tested the chemistry of uric acid chlorination in pools, so the results provide some scientific support for the argument agianst peeing in the pool. Whether you're a professional or recreational swimmer, the researchers point out that the study's findings should reinforce the lesson for everyone that urination while swimming is a no-no.

"Because uric acid introduction to pools is attributable to urination, which is largely a voluntary process for most swimmers, opportunities exist for significant improvement of air and water quality in pools via changes in swimmer hygiene practices," they conclude. "Specifically, if swimmers avoided urinating in pools, then air and water quality would likely improve independent of other changes in water treatment or air circulation."

Seriously, just don't do it. 

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