CALGARY (Alberta) • Canadian researchers studying urine levels in swimming pools have discovered just how high the levels are, and the results are not pretty.
Researchers at the University of Alberta took more than 250 samples from 31 pools and hot tubs in two Canadian cities. One 830,000-litre pool, which is about one-third the size of an Olympic-sized pool, had 75 litres of urine. A smaller pool had 30 litres.
Humans introduce "a variety of chemicals" into recreational waters through bodily fluids, and the separate news of an overnight colour change in the 2016 Rio Olympic pools highlights the need to monitor water quality, said the study, published in the journal Environmental Science and Technology Letters on Wednesday.
Although urine is sterile, its presence in pools is a public health concern because urine can mix with pool chemicals to harm swimmers' health, said researchers.
Asked about the study, the Alberta Health provincial ministry said it will take a "close look" at it. "Under the Public Health Act, the ministry has a regulation that provides standards," spokesman Tim Kulak said, adding that pools which fall short of standards may be closed.
Researchers measured for acesulfame potassium (Ace K), an artificial sweetener that passes through the body completely and is "an ideal urinary marker".
They found that concentrations of the substance in the pools and tubs were up to 570fold greater than in normal tap water. They also used the Ace K concentration to estimate urine levels.