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Recreational Water Illness

What are recreational water illnesses (RWIs)?

Recreational water illnesses (RWIs) are infections caused by germs that can live in contaminated water. These germs can be found in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers, or oceans. These germs can cause diarrhea or infection of the lungs, eyes, ears, stomach, skin, nose or throat. 

How are Recreational Water Illnesses (RWIs) Spread?

Swimmers not only share the water but the germs in it with every person who uses the pool. On average, people have about 0.14 grams of feces on their bottoms which, when rinsed off, can contaminate the 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 contaminated water can make you sick.

Keep in mind that chlorine does not kill germs instantly. Some germs, such as Cryptosporidium (or "Crypto"), are extremely chlorine tolerant.

Who is most likely to get ill from a Recreational Water Illness (RWI)?

People who are at greater risk of serious illness if they get RWIs include children and pregnant women. People with weakened immune systems such as people living with AIDS, individuals who have received an organ transplant, or people receiving certain types of chemotherapy are also at risk for serious illness.

Steps for Healthy Swimming

Here are a few easy and effective healthy swimming steps all swimmers can take each time they swim to help protect themselves, their families, and their friends from recreational water illnesses:

Make sure the water is safe for swimming!

Keep an eye out for signs or posts that may indicate the water is not safe to be in!
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.
Water play areas such as interactive fountains or spray parks are becoming more common. People may not realize that the water in these parks is reused. The spray water will rinse any contaminants (for example, diarrhea, vomit, and dirt) down into the water holding area and be sprayed again. As a result, it is possible for the water to become contaminated and make people sick.

Keep the pee, poop, sweat, and dirt out of the water!

  • Stay out of the water if you have diarrhea
  • Shower before you get in the water
  • Don't pee or poop in the water
  • Don't swallow the water

Every hour—everyone out!

  • Take kids on bathroom breaks
  • Check diapers, and change them in a bathroom or diaper-changing area–not poolside–to keep germs away from the pool
  • Reapply sunscreen
  • Drink plenty of fluids

Additional tips to protect yourself and others from RWIs:

  • Proper maintenance of chlorine and ph levels of pools, spas, hot tubs and fountains can limit the spread of germs.
  • When taking food to beaches or other recreational water sites, limit the amount of food taken and don’t feed animals and birds that can leave droppings.
  • Dispose of garbage properly especially diapers and other soiled materials.
Boston Public Health Commission
1010 Massachusetts Ave, 6th Floor, Boston, MA 02118.
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