Scientists Find Out How Much Pee Is Really In The Swimming Pool

A whiz of a study has determined just how much urine may be in the average public pool.

And urine for a shock: It’s more than anyone wants.

The news leak ― actually, the news about leaks ― comes from a team of researchers in Canada who were looking for a way to detect urine in a swimming pool.

Turns out, the solution was pretty sweet: an artificial sweetener called acesulfame potassium (ACE), found in a wide variety of consumer products.

The human body doesn’t break down acesulfame potassium, so it’s excreted in urine but remains detectable in bodies of water, even at varying pH levels and temperatures, according to Environmental Science & Technology Letters, a respected “pee-riodical.”

How much urine exactly?

Researchers monitored two public pools for three weeks for ACE. One pool contained 110,000 gallons of water, while the other held 220,000 gallons.

Based on the ACE measurements, researchers estimate that over the 3-week period, swimmers released 7.92 gallons of pee into the smaller pool, and nearly 20 gallons into the larger one.

In addition, the team analyzed 250 samples from 31 other pools and hot tubs, and discovered ACE levels were up to 570 times greater than the amount of pee found in tap water.

Urine contains nitrogenous compounds such as urea, ammonia, amino acids and creatinine, the study notes. These materials can react with disinfectants and cause eye and respiratory irritation. And people like professional swimmers and pool workers have reported asthma that’s been linked to their long time spent in the pool, according to the researchers.

Currently, there is no way to test for urine in pools, according to Live Science. Unless, of course, you see a yellow streak emanating from the bathing suit of the person next to you.

However, University of Alberta graduate student Lindsay Blackstock, the lead researcher of the study, suggests increased public education regarding appropriate swimming hygiene practices.

“We recommend that all pool users should rinse off excess personal care products in the provided showers before entering public pools,” she told Research Gate. “Additionally, we should all be considerate of others and make sure to exit the pool to use the restroom.”

CORRECTION: An earlier version of this story incorrectly called the artificial sweetener aspartame potassium. It is acesulfame potassium.