Lifehacker - This month the Journal of the American Chemical Society published a study that estimated there might be as many as 20 gallons of urine in a large swimming pool. To test for pee, scientists measured the concentration of an artificial sweetener that’s commonly found in processed food and able to pass through the body unaltered, the Guardian reported.
They tested 250 samples in 31 different pools. 20 gallons of pee sounds like a lot, but keep in mind, this was in a pool with a volume of about 220,000 gallons. Hot tubs had even larger levels of urine, according to the study. One hotel Jacuzzi they sampled had over three times the amount of sweetener than was found in the worst swimming pool.
While urine is sterile, compounds in urine, including urea, ammonia, and creatinine have been found to react with disinfectants to form byproducts known as DBPs that can lead to eye and respiratory irritation. Long-term exposure to the compounds has been linked to asthma in professional swimmers and pool workers.