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How To Stay Safe From Recreational Waterborne Diseases

You can reduce your risk by not swallowing water, and showering before and after swimming

Caregivers holding toddler, playing in ocean

Do you think your eyes turn red after swimming because of irritating chlorine? Wrong. Experts say urine and sweat are the actual culprits. Yep, you read that right. They bind to chlorine and create chemical irritants.


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This chemical concoction can burn your eyes, or at an indoor pool, irritate your lungs and make you cough. While it’s unpleasant, the fact is that the chlorine is doing its job, fighting off bacterial growth.

According to the U.S. Centers for Disease Control and Prevention (CDC), when bacteria goes unchecked, whether in swimming pools, water parks or lakes, it can cause recreational water-associated illnesses (RWIs) like an E. coli infection or cryptosporidiosis.

This may lead to flu-like symptoms after swimming in a pool or lake. You may experience diarrhea after swimming and other contaminated water symptoms like stomach pain, a fever and loss of appetite.

Despite these risks, the benefits of swimming tip the scale. Swimming is a supremely good form of exercise and fun. It offers a cardiovascular workout without putting stress on people’s joints, and it offers a way to relax in warmer weather. It also makes kids good and tired at the end of the day.

Infectious disease specialist Jessica Lum, MD, explains the type of recreational waterborne diseases you can get from contaminated lakes and pools and the simple precautions you can take to stay safe.

Common types of recreational waterborne illnesses

RWIs can include gastrointestinal, respiratory, neurological, skin, ear and eye illnesses. Here are some of the most common:


You can get cryptosporidiosis, which is contagious, from the parasite Cryptosporidium. This commonly happens when you accidentally swallow contaminated water that contains poop.

In addition: “Wash your hands with soap and water after changing diapers, using the toilet or preparing/eating food to prevent spreading cryptosporidium,” stresses Dr. Lum.


The infection can cause watery diarrhea, stomach pain and cramps, nausea and vomiting, as well as a low fever and loss of appetite. Symptoms typically start within two to 10 days of exposure.

If you have a healthy immune system, you may not need medical treatment, but make sure you stay hydrated. Some people, especially those with other medical conditions or who are immunocompromised, may need an antidiarrheal medication.

E. coli

Like cryptosporidiosis, an E. coli infection can cause diarrhea, stomach pains and cramps, loss of appetite and a low fever — and is contagious. And like cryptosporidiosis, you can get E. coli through fecal-oral transmission.

There are various strains of E. coli bacteria and, in most cases, you can recover on your own. But some people may need antibiotics and oral hydration. Depending on the strain, you may start to notice symptoms within an hour or up to 10 days after you’ve been exposed.


Known as the most common parasite infection in the U.S., giardiasis can cause an infection when you accidentally ingest a Giardia cyst. Once it settles in your small intestine, it can hatch and feed off your nutrients and grow.

Symptoms of the contagious parasite can cause watery diarrhea, fatty or greasy poop that floats, stomach pain and cramping, along with gas and bloating, nausea, loss of appetite and fatigue.

But about half of people with giardiasis never develop any symptoms. It can take one to two weeks to notice symptoms and those symptoms can last anywhere from two to six weeks. If you have symptoms, a healthcare provider may recommend an antiparasitic medication.


Also known as shigellosis or bacillary dysentery, this infection is caused by the Shigella bacteria and is spread through fecal-oral transmission.

Symptoms of a Shigella infection include watery, bloody diarrhea (and in some cases, your diarrhea may contain mucus or pus), stomach pain and cramps, vomiting and fever. You may start noticing these symptoms in one to three days after exposure.

If you have mild symptoms, you may be able to recover on your by resting and staying hydrated. If your symptoms are severe or if you have a weaker immune system, a healthcare provider may prescribe an antibiotic.


You may think you can only get Salmonella from food that’s undercooked or improperly prepared. But you can also get the contagious bacterial infection from water that’s untreated.

Symptoms typically appear within a few hours or days after you’ve been exposed. You may experience diarrhea, fever, stomach pains and cramps, nausea and vomiting and a headache.

Like many RWIs, Salmonella can be treated at home by staying hydrated — you should start to feel better in a few days. If you have severe symptoms, you may need an antibiotic.

Tips to stay safe while swimming

So, how can you stay safe while enjoying lakes, pools and water parks and avoid water-carried diseases? Dr. Lum shares some advice.

Don’t swallow water

“The most important thing is to avoid swallowing water,” says Dr. Lum.

It’s important to remember that chlorine doesn’t kill all germs instantly. There’s always a chance you’re swimming in contaminated water. Swimming pools, water parks and hot tubs all pose risks.


Swallowing just a little bit of contaminated water can make you sick.

Shower before and after swimming

You’ve heard it before. But do many of us really rinse off in the shower before (and after) entering the public pool?

Each of us carries .14 grams of fecal material into a pool. That’s why it’s important to shower before and after swimming.

“Shower and clean off afterward,” advises Dr. Lum. “Pay careful attention to handwashing because any bacteria on your hands can end up being swallowed if you touch your mouth or food.”

Dr. Lum also suggests taking bathroom breaks every 60 minutes and taking children on bathroom breaks every half hour to check their pants or diapers.

Check the weather

Many people don’t pay enough attention to the weather and how it affects bacteria levels in lakes, rivers and streams. Be careful on really hot days and after heavy rainfall, which both cause bacteria counts to rise.

Most states monitor the levels of bacteria in their lakes, rivers and streams and may have a website or app with updated water quality and advisories.

Bottom line?

So, is it safe to swim in lakes? Can pool water make you sick?

There’s no need to avoid lakes, swimming pools or water parks. By taking a few simple precautions, you can safely enjoy all the benefits of swimming. Just remember: Make sure to follow Department of Health guidelines/advisory notices in case there’s concern about water being contaminated.

And if you think you have an RWI, there is a chance you can recover on your own. Just make sure you stay hydrated and avoid any foods or drinks that can make your diarrhea worse, like caffeine and alcohol.

If you can’t keep any fluids down, have a fever higher than 103 degrees Fahrenheit (39.44 degrees Celsius), feel weak or lethargic and have confusion, Dr. Lum says don’t hesitate to call your doctor or head to the emergency room.

“Monitor for diarrheal symptoms after swimming in bodies of freshwater,” he emphasizes. “If your symptoms don’t resolve or you have a fever or signs of dehydration, you should be evaluated. If you’re immunocompromised, you should be evaluated by your doctor right away.”


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