Swimming in a public pool? You’re most likely swimming in pee

By analyzing pool water for a sweetener commonly found in human urine, Canadian researchers estimated that there were about 75 liters of pee in a large public pool-which contains about 833,000 liters or is a third of an Olympic pool.

Professor Xing-Fang Li from the University of Alberta told ABC Radio Melbourne their research found that in an average-sized 830,000-litre swimming pool there could be up to 75 litres of wee.

Of the 31 pools and hot tubs the team tested between May and August of 2014, every single one of them tested positive for ACE.

This was done by identifying the synthetic sweetener acesulfame-K (ACE) – which is widely consumed – and examining its excretion in urine.

In the future, the scientists suggest it may be possible to use ACE as a test to ensure that urine in pools is kept to a hygienic level. (We’re pretty sure the other four in five are lying) Even the world’s most famous pool-user, Michael Phelps, says “everybody” does it.

Nineteen per cent of adults have peed in a pool, according to a 2012 survey of Americans. Now researchers venture to know the full extent of the offense or how much urine can actually be found in the water. Because ammonia in urine and the chemicals in chlorine don’t mix well, they may be producing a potentially harmful reaction that could irritate your eyes and lungs.

Researchers tested two Canadian pools for the sweetener over a three week period. It’s also stable through varying pH levels and high temperatures, so it can be detected in hot tubs and pools. Although these seem like small amounts, Blackstock points out that the breakdown of nitrogenous compounds in pee, which form chemicals known as disinfection byproducts, can cause eye and respiratory irritation even in small amounts.

When researchers compared the levels of the sweetener in pool water and tap water, they found that the former contained up to 570 times more Ace-K.

She said the researchers wanted to use the study to promote better public hygiene. ‘Chlorine kills it, so it’s not bad’.

Add to the list: The amount of pee in the average swimming pool.

The study appeared this week in the journal Environmental Science & Technology Letters.