One of the biggest lies your parents told you was that there’s something in swimming pools that releases a dye when you pee. Despite the fact that no such chemical exists, scientists have figured out how much piss you’ve been swimming in. As you might have guessed, once you learn the amount you’re probably going to wish you could go back to not knowing.
Chemist Xing-Fang Li and a team of researchers reportedly figured out how to track the amount of urine in pools by measuring the amount of artificial sweeteners in their pee. As Li explains, artificial sweeteners are great for tracking pee because they go right through you. More specifically, the study measured the presence of a common sweetener called acesulfame potassium, also know as Ace-K. Using this system, they found that a commercial-sized swimming pool, 220,000 gallons of water, contained nearly 20 gallons of pee. To put into perspective, that’s about 2 gallons of pee in a residential pool. Don’t drink that in.
Of course, the study comes with a few caveats. First, researchers looked at 250 samples from 31 pools and hot tubs in Canada and the amount of pee in U.S. pools has yet to be determined. The way they track it also allows people who don’t consume artificial sweeteners to fly under the pee-dar. But if you’re in a pool, it’s safe to say you’re in urine, and research shows that’s not good for anyone.
So there is a retroactive, complicated, and scientific way to tell if your kid is sort of peeing in a pool, it’s just not what you thought it was when you were their age. If you want your kid to go undetected, maybe don’t feed them artificial sweeteners — Ace-K is found in everything from yogurt to ice cream to juices to baked goods to … you get it. Or you can try to get them to not pee in public places, and depending on how old your youngster is, that can be hard enough above water. You’re probably best off sticking with the dye lie.