How much pee is in your local swimming pool?

  • How much pee is in your local swimming pool?

How much pee is in your local swimming pool?

Ahead of the London 2012 Olympics, the USA swimmer, Ryan Lochte, said: "I think there's just something about getting into chlorine water that you just automatically go", and his team-mate, Michael Phelps, agreed it was acceptable behaviour. (Translation: pee.) One Olympic-sized pool (830,000 liters total) had about 75 liters of urine in it, according to the study.

Blackstock said testing results for hot tubs tended to be the most variable, with either really high or really low concentrations of the sweetener. Nevertheless, researchers in the current study say chemical byproducts in pools are "more mutagenic than corresponding tap water extracts", so doesn't hurt to have more data.

"Our study provides additional evidence that people are indeed urinating in public pools and hot tubs", Lindsay Blackstock, a graduate researcher at the University of Alberta, told The Guardian.

Before you dive into that hotel swimming pool, there's something you should know: There's probably human urine in there. After checking water samples from 31 swimming pools, the team reported that on an average swimming pool contains 75 liters of human urine.

Ernest Blatchley III, an environmental engineer at Purdue University, explained to NPR that "it's not uncommon for water in a pool to go unchanged for years", leaving the contaminated water to sit and worsen over time.

As the paper points out, the level of urine is 570 times greater than that found in tap water.

Yet chlorine isn't a flawless solution because recent studies have shown that urine and sweat can react with chlorine to form disinfection byproducts.

Sure, pee is sterile, but its chemicals can react with the pool water to form so-called "disinfectant byproducts", or DBPs.

It's always been something of an urban myth - that swimming pool containing literally gallons of wee. The widespread consumption of acesulfame-K (ACE), a stable synthetic sweetener, and its complete excretion in urine, makes it an ideal urinary marker.

A test for the presence of artificial sweetener better approximates how much pee might actually be in public pools and hot tubs. Neighborhood swimming pools contain about two gallons.

"Exposure to volatile DBPs, specifically trichloramine, in indoor swimming facilities can lead to eye and respiratory irritation (10-12) and has been linked to occupational asthma", the researchers wrote in their study.

The research team began by taking samples from 29 public pools in two Canadian cities and indeed found elevated levels of ACE.