The Spoils of Summer Swimming

More reports of illnesses suggest watching water hygiene

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HealthDay Reporter

FRIDAY, Aug. 6, 2004 (HealthDayNews) -- On your next trip to a pool, lake or ocean, take along a towel, some sunscreen and an awareness that you might be sharing the water with more than your fellow swimmers.

Public swimming places in the United States are experiencing an increase in the number of recreational water illnesses caused by the presence of microscopic organisms such as cryptosporidium, giardia, shigella and e. coli, according to the U.S. Centers for Disease Control and Prevention.

The trend is worrisome because these organisms can cause serious illnesses and even death. And since Americans make 360 million visits to recreational water areas every year, the CDC is encouraging people to pay more attention to the condition of the water they in which they swim.

"Swimming is great exercise and we want to continue to promote its benefits," said Michael Beach, an epidemiologist in the CDC's Division of Parasitic Diseases. "But the fact is that many of the nation's swimming pools and other recreational water venues are not being well-maintained, and the public has become lax about observing a number of practices that help maintain good quality swimming water."

Beach adds that the emergence of chlorine-resistant pathogens, such as cryptosporidium, heightens the danger and underscores the need for swimmers themselves to take more responsibility for water cleanliness. He estimates that about half of the outbreaks of water-quality illness in recent years can be traced to organisms that are no longer easily eradicated by conventional chemicals.

"It's a myth that chlorine can knock out all of the dangerous pathogens in swimming water," Beach said. "Even if pools are well-maintained, swimmers and the parents of young children using pools have an important role to play in insuring that human waste products, including urine and feces, are not introduced into the water."

Among the disease-causing microorganisms found in human waste are bacteria, viruses, protozoa and worms, all of which survive long enough to be passed along to others sharing the same recreational water.

The CDC has distilled its advice to swimmers and the parents of very young swimmers down to a set of relatively simple recommendations, for both swimmers and parents of youngsters splashing in the water.

For all swimmers:

  • Stay out of the water when you have diarrhea. This is especially important for kids in diapers. You can spread germs into the water and make other people sick.
  • Don't swallow pool water. In fact, avoid getting water in your mouth at all.
  • Practice good hygiene. Take a shower before swimming and wash your hands after using the toilet or changing diapers. Germs on your body end up in the water.

For parents of youngsters:

  • Take kids on bathroom breaks or check their diapers often. Waiting to hear "I have to go" may mean that it's too late.
  • Change diapers in a bathroom and not at poolside. Germs can spread to surfaces and objects in and around the pool and spread illness.
  • Wash your child thoroughly (especially the rear end) with soap and water before swimming. Everyone has invisible amounts of fecal matter on their bottoms that ends up in the pool.

Derek Scherr, water policy director for Clean Wisconsin, an environmental advocacy organization, said such advice also applies to adults and children using natural swimming venues, such as rivers and streams, and particularly to bodies of water that are not in motion, such as ponds and lakes.

In fact, Scherr noted, many recreational swimming holes are never tested for contamination or pollution, so swimmers need to be particularly cautious of swallowing that water or contributing further to the biological loads.

Although he advised that streams, lakes and rivers that look or smell bad should routinely be avoided, he also said it's impossible to tell whether a body of water is safe for swimming just by looking at it. A swimming hole that looks pristine, he added, might be just as contaminated as the worst stagnant pond.

"The bacteria and other organisms that cause illnesses in humans are much too small to be seen by the naked eye," Scherr explained. "While the nation's water is much cleaner now than before the passage of the Clean Water Act in 1972, we're still not at the place where all of our water is fit for humans to drink or use in recreational pursuits, such as swimming."

Scherr noted that, in general, flowing, clear and cooler water is safer for swimmers than standing, stagnant or warm water. Also, he said, beach and bank areas of lakes, streams and the ocean are popular with many other species, such as birds, which deposit fecal material and other waste products at the water's edge. Unfortunately, that's where humans tend to congregate.

In addition, in locales where rivers empty into lakes or the ocean, pollutants tend to settle out near the shores and beaches, contributing microorganisms and other pollutants to the popular swimming areas.

The U.S. Environmental Protection Agency (EPA) offers this advice for swimmers accessing natural water environments:

  • Avoid going for a swim after a heavy rainstorm. Rain typically washes pollutants from nearby land into lakes, rivers, streams and the ocean.
  • Look for drain pipes along the water front. Don't swim near them because they are discharging water that is heavily concentrated with pollutants.
  • Avoid water that has trash, oil slicks or other evidence of solid waste floating in it. Typically recreational water venues that have these elements present also have high levels of disease-causing microorganisms.

More information

For a complete list of parasites that lurk in water, visit the National Center for Infectious Diseases.

SOURCES: Michael Beach, Ph.D., epidemiologist, Division of Parasitic Diseases, U.S. Centers for Disease Control and Prevention, Atlanta; Derek Scherr, water policy director, Clean Wisconsin Inc., Madison

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