Peeing in a swimming pool is not only gross, it may also be harmful to your health , according to a recent study.

A study published in ACS' journal Environmental Science & Technology found that when mixed, urine and chlorine can form substances that can cause potential health problems. Chlorine is usually added to pool water to kill disease-causing microbes and prevent swimmers from getting sick.

"As people swim, splash, play - and pee - in the pool, chlorine mixes with sweat and urine and makes other substances. Two of these compounds, including trichloramine (NCl3) and cyanogen chloride (CNCl), are ubiquitous in swimming pools," researchers said in a statement.

Trichloramine is associated with lung problems, and the cyanogen can also affect the lungs, as well as the heart and central nervous system.

Scientists have not yet identified all of the specific ingredients in sweat and urine that could cause these potentially harmful compounds to form. So researchers looked at how chlorine interacts with uric acid, a component of sweat and urine, in their recent study.

They mixed uric acid and chlorine, and within an hour, both trichloramine and cyanogen formed.

According to a previous study reported by USA Today, both chemicals have been linked to health problems experienced by swimmers, lifeguards, and pool staff.

Though some uric acid comes from sweat, the scientists calculated that more than 90 percent of the compound in pools comes from urine.  

A 2012 survey revealed that 19 percent of adults cop to having peed in a public pool, USA Today reported. Previous studies have suggested that swimmers typically "drip out" as much as two shot glasses of urine when swimming.

Researchers say swimmers can improve pool conditions by simply urinating where they are supposed to - in the bathrooms.

The authors acknowledge funding from the Chinese Universities Scientific Fund, the National Natural Science Foundation of China and the National Swimming Pool Foundation.