NEW YORK — As summer begins, the Centers for Disease Control and Prevention is dropping a gross bombshell on swimmers explaining why their eyes burn in the pool.

Most swimmers believe that red, stinging eyes in the pool are caused by chlorine. While this isn’t completely false, there’s another disgusting element that creates the burning.

‘These by-products are the result of chlorine binding with sweat, urine, and other waste from swimmers.’

“Irritants in the air at swimming pools are usually the combined chlorine-by products of disinfection. These by-products are the result of chlorine binding with sweat, urine, and other waste from swimmers,” a report from the CDC said.

Yep, sweat, urine and other waste.

These irritants tend to be stronger in indoor pools, where they can contribute to poor air quality. The lack of air circulation can cause further irritation for swimmers, such as red eyes and stinging.

The CDC says that keeping doors and windows open allows for better air circulation.

Swimmers are advised to shower and use the restroom before getting in the pool to decrease the formation of irritants.