Do I have to shower before swimming? Pool safety questions answered

Sipping drinks on a pool lounger in the backyard or splashing with the kids at a waterpark are great ways to cool off in the summertime. But it turns out that all sorts of germs think of warm pools as tropical paradises too.

Without proper precautions, those germs can bring on nasty diarrhea illnesses or ear, eye and skin infections that are sure to ruin any long weekend.

Here are the answers to your most pressing questions about pool illnesses and what to do to protect yourself.

Do I really have to shower before going in a public pool?

If often seems that most people enter pool areas dry, probably feeling confident that they are fresh and clean. But even if you just showered that morning, chances are if you used a washroom that day, you could have tiny traces of fecal matter on your hands or the back of your legs that could help to contaminate a pool. The U.S. Centers for Disease Control and Prevention estimates that on average, people have about 0.14 grams of feces on their bottoms which can contaminate pool water.

One study the CDC did last summer found feces were frequently introduced into public pools. It collected water samples from numerous public pool filters and found 58 per cent of them tested positive for E. coli, which are bacteria normally found in feces.

While not all E. coli strains are harmful or pathogenic, the finding is a good clue that swimmers are either not showering before getting in, or that "foulings" -- typically children having "accidents" in the pool -- are contaminating the water.

Doesn't chlorine kill off most bacteria and germs?

Contrary to popular belief, the chlorine in pools does not kill all germs right away. It will kill most bacteria that cause illnesses in less than an hour -- but that's only if the chlorine and pH are at optimal levels. The bacteria that cause "hot tub rash" for example, can flourish in an improperly maintained pool.

Even if chlorine levels are ideal, many germs survive a few minute and while they are floating around water, they can be swallowed and cause diarrhea illnesses, especially in children, pregnant women and the elderly, or enter the eyes or ears to create other infections.

One nasty parasite, called Crypto (short for Cryptosporidium), has a tough outer shell and can live in a chlorinated pool for three to 10 days.

Crypto comes from human feces as well, and if swallowed, can cause swimmers to become ill. In the summer of 2007, crypto caused 5,700 illnesses in 20 counties -- one of the worst outbreaks ever.

Do I really have to ask my guests to shower going in my pool?

Many pool owners don't feel comfortable asking guests to shower before they cannonball into the deep end, but they really should insist.

"It's very important to ask guests to shower," says Mahesh Patel, the manager of healthy environments for Toronto Public Health.

"Just as we would be asked to do before going in a public pool, you should do that in a home pool. The same rules apply. Bacteria don't see any difference between a public pool and backyard pool."

For pool owners, the best way to reduce the risk of bringing in nasty germs is by having everyone shower before entering the pool. What's more, in the end, it will actually save a pool owner money. That's because by showering off sweat, skin creams and sunscreens, the pool filtration system doesn't have to work harder to keep the water clear and the pool owner won't have to add as much chlorine.

"It reduces the load that the chlorine has to react to. Chlorine can be more efficient when it doesn't have as much to break down. That's why it is very important to shower," Patel says.

Am I more likely to get sick at a public pool or backyard pool?

Patel believes that most public pools in Canada are very well-maintained. That's because local public health authorities in Canada tend to have much stricter pool and waterpark maintenance regulations than in the U.S.

Patel has been the lead for Toronto Public Health's healthy environments program for 12 years, and says he has "never seen a single outbreak of any kind of infection." Indeed, reports of illnesses related to pools and waterparks are rare in Canada. But Patel says the risk is never zero.

As for which kind of pool is safer, it's true that a backyard pool might have only a handful of visitors a day, while a public pool can see dozens, even hundreds, with the risk of contamination rising with each visitor. But the difference is that public pools are mandated to conduct checks of chlorine levels around the clock and to follow strict protocols after a "fouling." Visitors to backyard pools, on the other hand, have to put their faith in their hosts that they've kept the pool well-maintained. So it's difficult to say which kind of pool is safer.

But either way, Patel says there are a few things he likes to do to reduce his risk of illness.

"I go to a public pool every other day to swim and I always take precautions. I use ear plugs to keep the water out. I use a nose clip and I never swallow the water. And I've been swimming a long time and have never gotten sick," he says.

Is it okay to pee in the pool?

This could well be the most pressing question of all for swimmers: if you've really gotta go and you don't want to get out of the water, is it okay to pee in the pool?

Sort of, says Patel. But really, no.

"Peeing in the pool sounds gross and it IS gross. But let's remember: pee is sterile when it comes out, unless of course you have something like a bladder infection. There's nothing wrong with pee in itself. But, you shouldn't do it," he says.

"And the reason you shouldn't do it is because pee contains urea, which reacts with chlorine and create byproducts called chloramines. That's the stuff that gives chlorine its distinctive smell. Chloramines are volatile compounds that go into the air and they are not good to breathe them in, especially for kids," he explains.

So for the sake of your breathing -- and really, just the ick factor -- get out of the water when nature calls and do your business indoors.

What else can I do to stay safe?

Here are a few more tips from the CDC and other sources for avoiding swimming pool illnesses: