Experts are urging caution as Americans flock to pools this summer—microscopic parasites like Cryptosporidium and bacteria such as Pseudomonas can survive chlorinated water, causing diarrhea, rashes, and ear infections.
United States: As the summer holidays have now arrived, so too will the average citizen be looking to visit the local pool or lido.
However, swimmers should take caution because most people in society who use water parks and community swimming pools may be infected with germs capable of causing various diseases, a disease expert has cautioned.
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It implies that a shallow swim can lead to diarrhoea, a rash, or so-called swimmer’s ear – a nightmare that puts a damper on the summer vacation plans.
Although a powerful impact of chlorine may reassure you, a microbiologist claims that the chemical does not kill immediately and absolutely everything, as the Daily Mail reported.
How germy is the public pool? An infectious disease expert weighs in on poop, pee and perspiration – and the deceptive smell of chlorine https://t.co/u2daIO2pgh
— The Conversation U.S. (@ConversationUS) July 23, 2025
According to Lisa Cuchara, a professor of biomedical sciences at Quinnipiac University in Connecticut, “On hot summer days, few things are more refreshing than a dip in the pool,” the Conversation reported.
“But have you ever wondered if the pool is as clean as that crystal blue water appears?” she added.
Will her warnings therefore deter you next time you have determined to swim?
Swimming pools have seen the highest number of outbreaks of waterborne intestinal disease in England and Wales in the last 25 years, statistics indicate.
Cryptosporidium is the worst offender and is a parasite that can lead to a two-week-long stomach bug. She advised that the germ is transmitted when the faecal matter finds its way into the water and is ingested by another swimmer.
“Even in a pool that’s properly treated with chlorine, some pathogens can linger for minutes to days,” as per Professor Cuchara.
‘One of the most common culprits is Cryptosporidium, a microscopic germ that causes watery diarrhoea,” the expert added.
A small dose, which the naked eye will not recognize, is enough to infect dozens of people, she said, Daily Mail reports.
Another germ known as the Pseudomonas aeruginosa bacteria is another popular germ that can cause problems like a hot tub rash, where the skin infection is actually a rash of red, itchy, bumpy rash which forms around the location of hair follicles.
It may also provoke a swimmer’s ear, which is the infection of the outer ear canal frequently induced by the bacteria or fungi development in the ear canal when the water settles in there.