Chlorine And Urine: This Chemical Is Not Why Your Eyes Are Red From Pool Water

Most of us who've been in the pool know that if we open our eyes underwater for too long, they're bound to sting. But that's just the chlorine working its magic, right? Turns out, it might be a bit more than that. It could also be chlorine mixed in with pee and/or poop.

An annual swimming report released by the Centers for Disease Control and Prevention (CDC) found what many have probably suspected all along. Furthermore, the results suggested that the stronger the chlorine smell in a pool, the more likely it was filled with a heavier amount of urine, sweat or other bodily fluids. 

"When we go swimming and we complain that our eyes are red, it's because swimmers have peed in the water," said Michele Hlavsa, chief of the CDC's healthy swimming program, via Today. "The nitrogen in the urine combines with the chlorine and it forms what's known as chloramine and it's actually chloramine that causes the red eyes. It's not the chlorine itself. It's chlorine mixed with poop and sweat and a lot of other things we bring into the water with us."

Any sweat, urine or bodily fluids that interact with the chlorine may result in a chemical reaction that irritates sensitive tissues, resulting in irritation and the chlorine losing some of its cleaning power.

It's particularly dangerous to enter the pool with diarrhea, as some germs found in feces are even resistant to chlorine, including Crypto. Typically very young swimmers are known to be the ones spreading this, but anyone who has had diarrhea recently may carry the germs on their body.

Swimming is a healthy and fun activity, particularly during the summer. However, it's important to have your water tested regularly.

"Buy a pool tester," said Hlavsa. "You can get them at big box stores, pool supply stores and hardware stores. You're looking at both the chlorine level and the pH. The chlorine level you're looking for is 1 to 3 ppm. The pH should be between 7.2 to 7.8. The pH is important because it determines how effective that chlorine is."

Related Articles

Don't Pee in the Pool: May Result in Dangerous Toxins

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).