Safe swimming takes a bit of chemistry and a watchful eye

It’s the last thing you want to hear before heading off for a relaxing afternoon poolside, but here goes:

Don’t think of it as swimming. Think of it as taking a bath with a few hundred strangers.

So how can you minimize the chances of getting what the U.S. Centers for Disease Control and Prevention delicately refers to as “recreational water illnesses”?

First, says Nancy Menzel, a registered nurse, public health specialist and associate professor at the University of Nevada, Las Vegas School of Nursing, keep in mind that “swimming is wonderful exercise and it has many benefits. And people whose joints hurt can exercise in the swimming pool in a way they can’t on land.”

“But,” Menzel adds,”there are some things you can catch from exposure to recreational water.”

The CDC notes that recreational water illnesses are caused when contaminated pool water is swallowed or ingested by swimmers or comes into contact with a swimmer’s skin. The most common illnesses are diarrheal illnesses caused when feces-contaminated pool water is swallowed.

Chlorine and chemical treatments are designed to kill illness-causing germs in pool and spa water. The problem is that some troublesome microorganisms take longer to kill than others.

Cryptosporidium, for example, is “extremely chlorine-tolerant,” Menzel says, and can survive in improperly treated pool water for several days.

Before entering a pool or spa, take a look at the water. “If a pool looks green, don’t go in,” Menzel says.

Similarly, be wary of pool water that looks murky or otherwise off, and look at how well the pool deck and facility seem to be maintained.

Also take a look at your fellow swimmers. You might be wary if you notice diapered infants in the water.

Public pools’ chemical levels should be tested regularly, so feel free to ask a pool staff member about how often the pool is tested and if the most recent results are up to snuff.

Menzel says patrons also might wish to buy a box of inexpensive chemical test strips — the kind pool owners use to maintain their own pools — and do their own quick preswim test of a public pool.

Don’t let kids put pool water in their mouths or urinate in the pool. Be sure that anyone who exhibits symptoms of diarrhea stays out of the pool, and schedule a bathroom break for kids at least once every hour. Shower before swimming. And if an infant requires changing, do it in a bathroom or diaper-changing area and not near the pool.

When swimming in a lake or open water, avoid areas inhabited by waterfowl — they, too, can cause water-borne illnesses — and algae patches. And, Menzel says, towel off well when you’re finished swimming.

Be vigilant, too, about kids’ water play areas. Sometimes, Menzel says, “they find they’re not always as well-maintained” as pools.