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 swallowing the water you cooling off in, says Daniel Elwell, MD, emergency department interim medical director at Ascension Providence.

Ascension Providence now offers Dell Children’s Emergency Care, providing enhanced pediatric emergency closer to home. Ascension Providence and Dell Children’s Medical Center of Central Texas are a 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. 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

Elwell 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.

“Historically, there have been periodic surges in crypto outbreaks,” Elwell said. “It is unclear if crypto cases are truly more prevalent now, or if enhanced tracking systems are simply following the cases better.”

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
  • If you or your child has diarrhea, don’t go swimming for two weeks after the illness passes
  • Treat contaminated pools with high levels of chlorine and stay out of the pool until the chorine levels are safe for swimming

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. Be sure that electrical circuits around your boat and boat dock are well maintained and properly protected.

Elwell said electric shock can happen when a person in the water grabs something electrical, or when an electrical current leaks into surrounding water. Injuries from electric shock include burns, water in the lungs from drowning.

This kind of accident is most likely to occur when something is plugged in near 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 be sure to maintain the wiring of the pool lights,” Elwell said.

Additional water safety tips can be found at