Ready for summer swimming? Beware of hidden harms


While cooling off in a pool or lake may look refreshing on a hot summer’s day, you may want to consider some dangers lurking beneath the surface before taking the plunge.

Things like parasites and electric currents are a couple of dangers you can’t see in the water, but could harm you while swimming.

Avoiding poo-poo parasites

It’s as gross as it sounds, Cryptosporidium, or “crypto,” is a parasite that causes a diarrhea-illness when it gets into your body. In 2016, at least 32 crypto outbreaks were reported in pools or water playground in the U.S., compared with 16 outbreaks in 2014, according to a recent report from the Centers for Disease Control and Prevention.

When it comes to crypto and other parasites, it’s best to avoid beverages while in the water, says Christopher Ziebell, MD, emergency department medical director at Dell Seton Medical Center at The University of Texas, part of Ascension, the largest nonprofit health system in the U.S. and the world’s largest Catholic health system.

“Avoid having cups and other things in the water with you to avoid getting sick,” Ziebell said. “Anything you drink that may have contaminated water in it can spread a parasite. Toys that squirt water can also be a form of risk so be careful when playing in pools and lakes.”

Crypto in growing numbers

Ziebell said although it might seem like there are more crypto cases now than ever before, it might be just because of our increased awareness of parasites.

“It is hard to say if the prevalence of crypto is actually increasing, or if awareness is causing us to test for it more,” Ziebell said. “When we don’t test for it, we don’t find it. When we do test for it, then we find it, and now it counts as a new case.”

Ways to avoid crypto:

  • Avoid drinking untreated water from a lake or pool that is contaminated with crypto
  • Don’t swallow water, ice, or beverages contaminated with infected human or animal feces
  • Don’t touch your mouth with contaminated hands like from changing a diaper

Wash items soiled with feces or vomit as soon as possible.

The best way to avoid spreading crypto is to have good hygiene. Wash your hands with soap and water often. Alcohol-based sanitizers don’t work against crypto.

Crypto symptoms

Symptoms usually begin two to 10 days after infection and include diarrhea, stomach cramps or pain, dehydration, nausea, vomiting, fever and weight loss.

Most people with healthy immune systems will recover without treatment, according to the CDC. But there are some things you can do to relieve symptoms if you are infected, like drinking plenty of water, maintaining a well-balanced diet and avoiding caffeine and alcohol, which can dehydrate you. But talk to your doctor if you think you might have crypto.

Electricity in the water

In addition to parasites, there are other dangers that can swim in the water with you. While taking a dip in the pool, lake or ocean, be mindful of electric shock drowning, which happens when swimmers are exposed to electric currents in the water.

Electricity in the water usually comes from the wiring of a dock or marina, or from boats connected to a power supply.

To avoid electric shock drowning, never swim in marinas, docks or boatyards.

Ziebell said some electric shock cases happen when a person in the water grabs something electrical and the electricity passes through the person. Injuries from electric shock include burns, and water in the lungs from drowning.

This kind of accident is most likely to occur when something is plugged into the water, like speakers or other sound systems, so be careful when choosing where to plug in your entertainment.

“Keep all things electrical away from your pool, and keep yourself away when you are wet and not properly grounded,” Ziebell said.

Additional water safety tips can be found at