Recreational Water Illnesses (RWIs)

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How are Recreational Water Illnesses (RWIs) Spread?

Diarrheal Illnesses

Swallowing water that has been contaminated with feces containing germs can cause diarrheal illness.

Swimmers share the water -- and the germs in it -- with every person who enters the pool. On average, people have about 0.14 grams of feces on their bottoms which, when rinsed off, can contaminate recreational water. In addition, when someone is ill with diarrhea, their stool can contain millions of germs. This means that just one person with diarrhea can easily contaminate the water in a large pool or water park. Swallowing even a small amount of recreational water that has been contaminated with feces containing germs can make you sick. Remember, chlorine does not kill germs instantly, and some germs, such as Cryptosporidium (or "Crypto"), are extremely chlorine tolerant.

In addition, lakes, rivers, and the ocean can be contaminated with germs from sewage spills, animal waste, and water runoff following rainfall. Some common germs can also live for long periods of time in salt water.

Other RWIs

Many other RWIs (skin, ear, eye, respiratory, neurologic, wound, and other infections) are caused by germs that live naturally in the environment (for example, in water and soil). If disinfectant levels in pools or hot tubs are not maintained at the appropriate levels, these germs can multiply and cause illness when swimmers breathe in mists or aerosols of or have contact with the contaminated water.

Why Doesn't Chlorine Kill Recreational Water Illness (RWI) Germs?

Chlorine (in swimming pools and hot tubs) kills the germs that cause recreational water illnesses (RWIs), but the time it takes to kill each germ varies.

In pools and hot tubs with the correct pH and disinfectant levels, chlorine will kill most germs that cause RWIs in less than an hour. However, chlorine takes longer to kill some germs, such as Crypto (short for Cryptosporidium). Crypto can survive for days even in a properly disinfected pool. This is why it is so important for swimmers to keep germs out of the water in the first place.

To protect yourself, your family, and other swimmers from RWIs, it is essential to learn and practice healthy swimming behaviors.

Medically Reviewed by a Doctor on 2/5/2015

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  • Recreational Water Illnesses - Sources

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  • Recreational Water Illnesses - Chlorine

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  • Recreational Water Illnesses - Prevention

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