Scientists used an artificial sweetener found in urine to measure how much pee is in swimming pool water.
A scientific study of swimming pools and hot tubs in Canada has found a large pool of about 830,000 litres could contain up to 75 litres of urine. Using a new test to estimate the amount of urine added to public swimming pools and tubs, they measured the levels of an artificial sweetener found in processed food which is passed unaltered in urine.
University of Alberta graduate student and lead author Lindsay Blackstock told The Guardian the study provided new evidence people were indeed peeing in pools and hot tubs.
She said the research was unable to say in percentage terms how many of the people going for a swim or a soak urinated in public pools.
“We did not monitor the number of pool users over the three week period…so there is no way we could estimate the number of individual urination events per day,” she said.
She said the researchers wanted to use the study to promote better public hygiene.
The research also found people were peeing in hot tubs, which had higher levels of urine than swimming pools.
Findings published in the Environmental Science and Technology Letters said the team sampled 31 pools and hot tubs in two Canadian cities and used the average concentration of the artificial sweetener in Canadian urine to approximate the volume of urine in pools.
The Guardian said while urine is sterile, some compounds can react with chlorinated water and cause eye and respiratory irritation.
It’s also a myth that public pools add dye to the water to form a coloured cloud around a swimmer who pees.