These are all the germs lurking in your public pool, waterpark

Click to play video: 'University of Alberta researchers look into how much pee is in pools'
University of Alberta researchers look into how much pee is in pools
Some researchers from the University of Alberta decided to look into how much urine ends up in swimming pools. Su-Ling Goh reports on what they discovered – Mar 1, 2017

If you’re splashing around at a water park or public pool, whatever you do, don’t take a gulp of the water.

You’re basically wading in a public bath filled with strangers’ germs and dirt, experts say.

“Every time you move, you’re releasing a million microbes and that’s all going into the water,” Jason Tetro, a Canadian microbiologist and bestselling author, told Global News.

“Little viruses could end up in your swimming pool giving you ear aches, gastrointestinal problems, pink eye. Usually, there’s a high enough chlorine concentration to kill them,” Tetro said.

The American Chemical Society warns that public pools “are not always as clean as you might think, even when disinfected.”

Here’s a look at what may be wading in at a water park or public pool.

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In 2013, the U.S. Centers for Disease Control and Prevention warned that feces are “frequently” introduced into the pool water by swimmers.

Fifty-eight per cent of pool filter samples tested positive for E. coli, bacteria that are normally found in the human gut and feces.

One in four adults say they would swim within an hour of having diarrhea and 52 per cent admit they rarely or never shower before jumping into a pool. This does not bode well for clean pool water.


Yup, you know you’ve relieved yourself in a pool before. There’s a reason why pools are often nicknamed public bathrooms.

“Urine is, for the most part, sterile anyway. But components of urine can react with chlorine to create potentially carcinogenic chemicals. But it’s so low in concentration,” Tetro said.

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READ MORE: How much pee is in the pool? New Alberta research measures ‘water sweetness’

Nineteen per cent of adults have peed in a pool, according to a 2012 survey. In a 2017 University of Alberta study, scientists found that a 110,000-gallon pool contains about seven gallons of urine — about enough to fill a medium-sized trash bin.

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Recreational water illnesses – or RWIs – are caused by germs spread by swallowing, breathing in mists or having contact with contaminated water in pools, hot tubs and water park areas, according to the CDC.

RWIs cause a wide variety of infections, from gastrointestinal issues, skin, ear and respiratory problems, and – the most common – diarrhea.


And then there are the germs that aren’t killed by chlorine. Earlier this year, the CDC warned about a rise in illnesses tied to cryptosporidium – or “crypto.”

“Crypto is not easily killed by chlorine and can live up to 10 days in well-treated pools. Just a small number of crypto germs can make someone sick. That’s why it is important to keep crypto out of the water in the first place,” Michele Hlavsa, a CDC epidemiologist and chief of the agency’s Healthy Swimming Program, said in a statement.

READ MORE: A parasite that chlorine can’t kill could be lurking in your pool

Hlavsa called on those who are feeling under the weather to stay out of the water. The CDC is also insisting that there are great public health reasons why you should rinse off before you get into the pool and after you get out.

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Harmful compounds

Scientists say health issues surface when chlorine and other disinfectants interact with the substances we add to the water (from our sweat to sunscreen and urine), creating harmful compounds.

“Studies of swimming pools have identified many of the resulting compounds, called disinfection byproducts. And testing has shown that they can cause genetic damage to cells in lab settings,” the ACS said in a statement.

READ MORE: Here’s what’s really in your pool water, according to a U.S. report

“Other reports have found that some people who swim or work in and around pools have higher rates of certain health problems, including respiratory symptoms and bladder cancer.”

In their research, the ACS team studied water samples from public and private pools and hot tubs. They found more than 100 byproducts in the water from when disinfectants interacted with urine, sunblock, sweat and germs.

Open waters come with issues, too

Oceans and lakes come with their fair share of germs, too.

“Your greatest chance of infections is from naturally occurring microbes. You’re not worrying about the human component because there’s so much volume of water. There are a number of different types of fungi, amoeba and bacterial species that could potentially cause problems,” Tetro said.

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How to protect yourself

So how do you stay safe? Simple hygiene can go a long way.

CDC recommends that all swimmers take the following steps to prevent infections while swimming:

  • Keep feces and other contaminants out of the water.
    • Do not swim when you have diarrhea.
    • Shower with soap before you start swimming.
    • Take a rinse shower before you get back into the water.
    • Take bathroom breaks every 60 minutes.
    • Wash your hands with soap after using the toilet or changing diapers.
  • Check the chlorine level and pH before getting into the water.
    • Pools: Proper chlorine (1–3 mg/L or parts per million [ppm]) and pH (7.2–7.8) levels maximize germ-killing power.
    • Most superstores, hardware stores, and pool supply stores sell pool test strips.
  • Do not swallow the water you swim in.

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