That sign in the locker room that says "shower before swimming" is not a mere suggestion. While very few of us would skip a post-swim shower (got to get that icky chlorine off!), we should probably follow the pre-swim rules a lot more.
One of the dirtiest problems for pools is that many don't follow that one rule, making the pool much more dirtier than we ever imagined.
Why showering before swimming is important
"If we don't shower before we get in the water, we're going to carry in whatever's sitting on our skin," says Michele Hlavsa, RN, MPH, an epidemiologist and the chief of Healthy Swimming and Waterborne Disease Prevention at the CDC. That includes natural oils, sweat, makeup and other personal care products, urine, and, yep, fecal matter.
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All of these materials have one thing in common, says Hlavsa: nitrogen. When nitrogen mixes with the chlorine in the pool, chemical irritants called chloramines are formed, which is problematic for two reasons, she says.
The first issue is that some of the very-important chlorine is now being tied up as chloramines rather than protecting us from the germs in the pool. Chlorine still manages to kill most of them, thankfully, but the survivors, when swallowed or inhaled while swimming, lead to some 10,000 illnesses a year among Americans, LiveScience reports.
The second cause for worry is the chloramines, which makes the pool smell like, well, a pool. That smell we often attribute to a clean pool is actually the chloramines, which are also responsible for making your eyes red when you swim. The irritants are also thought to trigger asthma attacks and may even lead to some skin irritation, she says.
And all this time we've been blaming chlorine! It should be known chlorine initially gained favor because of its ability to help prevent the spread of polio.
According to Hlavsa, researchers continue to debate the risks of chloramines, though, especially as they may pertain to asthma, as well as other chemical reactions between chlorine and the gunk we add to the mix.
"We've forgotten how important chlorine is in keeping us safe from germs in the water," she says. "We have to keep in mind that it's really important to shower before we go into the water so we leave more chlorine in the water to kill germs."
While using soap, rinse and repeat is still the safest bet, a 2012 study found that even just a 60-second rinse goes a long way.
Still, keep in mind next time you feel like slacking on your pre-swim shower that "everything that rinses off of our body we share with other swimmers," says Hlavsa. "In some ways, it's like getting into a big bathtub together."
Another thing to look out for in the common pool is a new parasite.
A new report, issued June 2015, documented 90 outbreaks in recreational water venues between 2011 and 2012. The CDC found at least 1,788 cases, 95 hospitalizations, and one death. The cases were tracked in 32 states, as well as Puerto Rico.
A leading cause of the outbreaks is cryptosporidium, otherwise known as “crypto.” The parasite is easily transmittable in pools or at water parks because of its small size and its ability to resist chlorine disinfection, says the CDC.
As you can see showering is very important. So the next time you decide to go swimming, don't forget to lather, rinse, repeat!