By Drs. Sally Robinson and Keith Bly

When people think of risks associated with swimming they usually think of sunburns or drowning. Most swimmers don’t realize that the water itself can make them sick.

Recreational water illnesses (RWIs) are spread by swallowing, breathing or coming in contact with water that has been contaminated in swimming pools or hot tubs, and at water parks, lakes, rivers or oceans. 

Symptoms of RWIs include skin, ear, respiratory, eye and wound infections. The most commonly reported RWI is diarrhea, which is caused by germs such as Cryptosporidium, Giardia, Shingella, and E. coli. If contaminated water is swallowed a person may become sick; many diarrhea-causing germs do not have to be swallowed in large amounts to make a person ill.

If a swimmer has diarrhea, the germs that they carry can contaminate the water if they have an "accident" in the pool or if they don’t clean themselves well after using the restroom. People with diarrhea can easily contaminate large pools or water parks because their stool contains millions of germs. Lakes, rivers and the ocean can be contaminated by sewage spills, animal waste and water runoff following rain. Some common germs can live for long periods in salt water.

Chlorine in swimming pools kills the germs that may make people sick, but it doesn’t kill them right away. Most germs that can cause RWIs are killed by chlorine in less than an hour, but some can survive for days, even if the pool has been properly disinfected.

Here are some tips to prevent the spread of recreational water illnesses:

·        Do not let children swim if they have diarrhea, especially if they wear diapers.

·        Tell your children not to swallow pool water and to try to avoid even having water get in their mouths.

·        Teach your children good hygiene habits, such as taking showers before swimming and washing hands after going to the bathroom. You should also be sure to wash your hands after changing diapers.

·        Wash your child thoroughly (especially their bottom) with soap and water before swimming. Everyone has invisible amounts of fecal matter on their bottoms.

·        Take children on bathroom breaks and check diapers often while swimming.

·        Change diapers in a bathroom, not beside the pool. Germs can spread to surfaces and objects in and around the pool and spread illness. Wash hands after changing diapers.

Germs that live naturally in the environment cause other RWIs, such as eye, skin, ear and respiratory infections. If a pool has not been properly treated, the germs can cause swimmers to be sick.

Children, pregnant women and people with compromised immune systems (such as those with AIDS, those who have received an organ transplant or those taking certain types of chemotherapy) are more likely to get sick from RWIs.

Remember, you share the pool with everyone in it. Healthy swimming behaviors can protect your family from RWIs and help stop germs from getting in the pool.

Dr. Sally Robinson is a pediatrician in the division of children’s special services at the University of Texas Medical Branch at Galveston. She teaches medical students about caring for children with chronic medical conditions. Dr. Keith Bly is a hospitalist and assistant professor of pediatrics at UTMB.

The Your Health column is written by health and medical experts at the University of Texas Medical Branch at Galveston. The column focuses on topical health issues that we believe are of interest to your readers. It is e-mailed every Tuesday. If you have any questions about the column, or would like to suggest topics, please contact John Koloen, media relations specialist, at (409) 772-8790 or email