Swimming Pools and Hot Tubs Are Even Dirtier Than You Think

You may want to think twice before taking a dip. 

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A dip in the pool provides a welcome chill on a hot summer day, but a new study suggests that refreshing water might not be so clean, despite disinfectants like chlorine.



Whether you’re diving into a public swimming pool or a personal hot tub, there will be pathogens present. Disinfectants, such as chlorine, help to kill those pathogens. But the disinfectants also react with sweat, urine, and other substances that swimmers leave behind, according to the study published in the American Chemical Society journal Environmental Science & Technology. These reactions cause compounds scientists call disinfection byproducts.

In lab settings, testing has shown that these byproducts can cause genetic damage to cells. Other studies suggest those who frequently swim or work in and around pools could be more likely to have certain health problems, such as bladder cancer and respiratory issues.

During the study, researchers sampled water from both public and private pools and hot tubs, after both normal and excessive use. More than 100 disinfection byproducts were identified and tested to determine potential damage to cells. Pool samples were 2.4 times more likely to damage cells than the tap water used to fill them. Hot tub samples were 4.1 times more likely to damage cells.

Swimmers can do their part to keep pool and hot tub water cleaner by showering before taking a dip and using toilets when needed. Pool owners and operators can clean facilities and change the water more frequently to reduce the amount of potentially harmful disinfection byproducts in the water. Check out these five smart tips for staying safe in public pools.