Swimming is the most popular recreational activity for children in the U.S. It's also one of the best ways to get needed physical activity, have fun, and cool off in the hot summer weather, but it's important for swimmers and hot tub users to know the steps they should take to protect themselves and others from potential health risks.

According to a study of public pools done during last summer's swim season by the Centers for Disease Control and Prevention; there are a lot of germs in pool water. The study found pseudomonas aeruginosa, which can cause skin rashes and ear infections; Cryptosporidium and Giardia, germs that are spread through feces and cause diarrhea; and well over half of the samples tested showed E.coli, a bacteria normally found in the human gut and feces, and is a marker for fecal contamination.

While that discovery may make some swimmers squeamish, there are steps that people can and should take to ensure their pool or spa water is as clean as possible, both in public and residential pools and spas.

Public Swimming Pools:


•Do not swim when you have diarrhea and for up to two weeks after symptoms have stopped;

•Do not swallow pool water or get pool water in your mouth;

•Shower before swimming

•Wash your hands after using the toilet or changing diapers;

•Take children on bathroom breaks or change diapers often;

•Change children's diapers in a bathroom, not at poolside.


Inflatable and Plastic Pools: Small inflatable and plastic pools are typically filled with tap water. Some people in the United States have a disinfectant in their tap water but this is not adequate to kill germs that may get into water used for swimming. It may not be practical to kill germs by adding chlorine bleach to small pools because the chlorine dose cannot be easily determined or safely monitored. These pools also do not have filters to remove particles that could prevent the chlorine from working well. Using these types of pools increases the risk of spreading illness brought into the water by swimmers with a diarrheal illness. Any household deciding to use these types of small pools should follow the steps below to reduce the spread of illness:


•Give children a cleansing soap shower or bath before they swim;

•Talk to parents or caregivers about their children's health before others use the pool;

•Remind children to avoid getting pool water in their mouths;


• Clear the pool of children, empty, and then clean it. In the case of diarrhea incidents, once the pool has been cleaned and is completely dry, leave it in the sun for at least four hours.

•Medium and larger-sized inflatable and plastic pools that cannot be emptied daily should have filters and appropriate disinfection systems that meet the same codes and requirements as full-sized swimming pools.

Hot tubs and spas: Improperly maintained spas can cause infections of the ear, eye and respiratory tract, rashes, and other illnesses. Chlorine and disinfectants help fight these diseases but they don't work immediately, sometimes taking hours or days to kill new infections, and some bugs are more resistant to chlorine than others. In addition, these chemicals evaporate more quickly because of the higher temperature of the water in the tubs, making it very important for users to ensure the hot tub they are using is maintained properly and adopt good hygiene habits, including:

•Refrain from entering a hot tub when you have diarrhea;

•Avoid swallowing hot tub water or even getting it into your mouth;

•Shower or bathe with soap before entering the hot tub;

•Observe limits, if posted, on the maximum allowable number of bathers;

•Exclude children less than five years of age from using hot tubs;

•If pregnant, consult a physician before hot tub use, particularly in the first trimester;

•A well-chlorinated hot tub has little odor, a strong chemical smell indicates a maintenance problem;

•The sides of the hot tub should be smooth; tiles should not be sticky or slippery;

•Pumps and filtration systems make noise and you should hear them running while you're using a hot tub;

•Hot tub temperatures should not exceed 104º F.

For more information about illness related to swimming pools and spas visit cdc.gov/healthywater/swimming.