Water Holds Pleasures, and Menaces That Lurk
By JANE E. BRODY
Published: July 11, 2011
For me, swimming is also a meditation exercise; with nothing but the water to distract me, I get some of my best ideas while swimming laps. Dr. Oliver Sacks, the neurologist and best-selling author, wrote in an autobiographical essay called “Water Babies” that the mind-altering properties of swimming can inspire as nothing else can.
But whether you swim in a river, lake, ocean or pool, the last thing you want afterward is what the Centers for Disease Control and Prevention calls a “recreational water illness,” an infection or irritation caused by germs or chemicals contaminating the water.
These unseen pollutants can cause ailments of the ears, eyes, skin, nervous system, gastrointestinal and respiratory tracts, and any cut or scratch you may have. Five years ago, the centers examined 78 waterborne disease outbreaks in 31 states associated with recreational sports, a “substantial increase” in the number of reports from previous years. The outbreaks involved 4,412 cases of illness, 116 hospitalizations and five deaths.
And while you might expect otherwise, fully 94 percent of the cases resulted from swimming in treated water — pools and the like that were supposed to be sanitized. The usual culprit was a bacterium called Cryptosporidium, which is resistant to chlorine.
Fortunately, there are measures every swimmer can take to keep water play safe.
The most common problem is diarrhea from swallowing water contaminated with germ-laden feces. Should one swimmer have diarrhea, the millions of germs in that person’s stool “can easily contaminate the water in a large pool or water park,” the C.D.C. reports.
Natural waters can become contaminated with fecal and other germs by sewage overflow, storm water runoff, boating wastes and septic systems that malfunction. It is a myth that seawater quickly kills pathogens; coastal waters in particular are rich in nutrients that enable bacteria to survive despite the salt.
Viruses can be even more of a problem, because they live longer than bacteria in saltwater. In one study of beaches in Texas, intestinal viruses were found in more than 40 percent of waters listed as safe for recreational swimming based on bacterial standards.
Protection starts by following usual health department rules to shower before entering a pool — not just a superficial rinse but a full-body soak with special attention to germ-laden body parts. Respect fellow swimmers by staying out of the water if you have a diarrheal illness. Keep ill babies away, too — swim diapers are no guarantee that they won’t sicken others.
Be sure pool water is tested regularly for proper chemical balance: twice a day in public facilities and two or more times a week in private ones. Concerned swimmers can invest in chlorine test strips (available at pool supply and home improvement stores) to check the level of disinfectant.
Inflatable and hard plastic kiddie pools are often breeding grounds for infectious organisms. Most are filled with tap water without added disinfectants. The C.D.C. recommends that children be given “a cleansing soap shower or bath” before they use a kiddie pool, which should be emptied and scrubbed clean after each use.
Finally, stay out of water that has been closed by pool or health officials, whose job it is to make sure that water is safe for swimming.
But even a well-maintained swim site can result in inflammation of the ears and eyes. So-called swimmer’s ear (acute otitis externa) results in pain, tenderness, redness and swelling of the external ear canal, usually caused by a bacterial infection in the outer ear canal.
Residual moisture is the primary culprit, and the best preventive is to keep the ear canals dry with earplugs or a tight-fitting cap. After swimming, tilt your ear first to one side then the other and shake out any water that got in. Then dry your ears thoroughly with a towel (or hair dryer set on low) and alcohol-based ear drops.
Eyes are even easier to protect. I use goggles wherever I swim, both to protect my eyes and help me see. Wear goggles that fit snugly and are your own. Borrowed goggles could be contaminated with germs that cause conjunctivitis (better known as pinkeye).
Without goggles, the chemicals used to disinfect pools can irritate your eyes, especially when combined with human urea or sunlight. If your eyes are immersed in pool water, one competitive swimmer suggests neutralizing the chlorine with a few drops of milk. The salt in ocean water can also be irritating.
In addition to polluting microbes, ocean waters sometimes have free-swimming organisms that cause swimmer’s itch, as well as the stinging cells of jellyfish.
Swimmer’s itch, or cercarial dermatitis, is a rash caused by an allergic reaction to microscopic parasites of birds and mammals that are released into both fresh water and saltwater by snails, their intermediate hosts.
Avoid swimming in areas where snails are common or where signs have been posted warning of this problem or the presence of jellyfish. To counter the effects of swimmer’s itch, use a corticosteroid or anti-itch cream, and bathe in Epsom salts or baking soda.
If stung by jellyfish, try dabbing the skin with vinegar to neutralize the toxin and relieve the pain. People with a bee sting allergy should be especially careful to stay out of waters containing jellyfish. If you are allergic to one, you may well be allergic to the other.