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Something in the Water

Viruses, bacteria and disease may lurk invisibly where you swim. It's enough to make you sick.

July 12, 1999|JANE E. ALLEN | TIMES HEALTH WRITER

Picture the solitary surfer on the perfect wave.

Alone?

Not really. A host of nasty creatures too small to be seen share that water.

The next time you plan a cooling splash in the ocean, a dip at a lake or a swim at an indoor pool with water slides and fountains, remember you could have company that leaves you with a medical memento of your visit.

On the other hand, the rate at which occasional beachgoers and other bathers get sick from water they inhale or swallow is probably fairly low, although no one has gotten a handle on the precise rate. The risk rises with exposure.

Surfers--those inveterate water lovers--are continuously exposed to the microscopic zoo that thrives in the sea. Despite warnings to stay out of the water for 72 hours after a storm, surfers usually take their chances when waves are churning brown and murky with urban runoff.

"If you're on the beach and you see perfect barrels firing offshore, it can be the color of cappuccino and you're going to put on your wetsuit and go," says Steve Hawk of San Clemente, a writer and former editor of Surfer magazine. Ask him about skin problems and other waterborne illnesses and he responds: "I've had them all."

Water supports not only native marine creatures, but other invaders that wend their way there, invisibly carried by people or pets who take a plunge.

If you could peer into a drop of water where people are at play, you might find tiny round or rod-shaped bacteria that make their usual home in the guts of humans and animals. Or tiny, roundish viruses from human waste. That drop could also contain weakened forms of polio excreted by people who have just been vaccinated. And perhaps tiny plants called phytoplankton in toxic red tides that may trigger reactions in swimmers, fishermen or passersby on piers who inhale sea spray. Health officials post signs and close beaches when tests show that levels of biologic pollutants are unsafe. They monitor total coliform--a group of bacteria that come from soil, plants, animals and humans--as well as fecal coliform, most of which is the common gut-dweller e. coli, along with the ball-shaped enterococci, another intestinal bug that often enters the ocean through storm drains. These three "indicator" bacteria don't often produce illness, but at sufficient concentrations they can indicate the presence of other microorganisms that can make you sick.

"Any time you see water flowing across the beach, you shouldn't swim in it or within 50 yards of that area upcoast or downcoast. If you see a storm drain that's flowing, you shouldn't swim next to it," says Charles McGee, microbiology laboratory supervisor for the Orange County Sanitation District. The agency monitors 17 miles of coastline in Orange County from Memorial Day through Labor Day. On July 1, health officials closed a mile of Huntington State Beach because of high bacteria; they have been searching for a suspected sewage source.

Lakes and dams are other potential trouble spots for illnesses spread by people who use recreational waters as toilets.

Even indoor pools, where you might expect chlorination to annihilate anything dangerous, can pose a threat to lifeguards who sit about 8 feet above the surface. Bacteria killed by the chemicals hover in sprays and can hitch a ride deep into the lungs with every breath, triggering inflammation and scarring. Indoor and outdoor pools pose a more general hazard to swimmers when chlorine isn't sufficient to kill microorganisms.

Pathogens Collect Near the Water's Surface

So choose your wet playgrounds carefully.

Some of the biggest concentrations of bacteria and viruses are 1 to 2 feet below the surface of the water, where some people "slyly and unbeknownst to their swimming partners" are relieving themselves or coughing up material that finds "little tidal recesses where it sort of collects, as flotsam and jetsam will do," says Dr. Mark Renneker of San Francisco, founder of the Surfer's Medical Association.

Renneker suspects these bacteria are responsible for more cases of illness than environmental scientists and doctors ever hear about. He hypothesizes that bacteria and viruses are causing "subclinical" infections, which may make someone feel slightly sick, but not bad enough to seek care.

Jed Alan Fuhrman, a marine biology professor at USC, looks at the viruses--called enteroviruses--that can cause intestinal and neurological symptoms. They include hepatitis, which causes liver infection; coxsackie, which can cause an inflammation of the membrane around the brain called meningitis; and rotavirus, which is responsible for severe diarrhea. He tests water at piers and where storm drains empty to see if viral concentrations are sufficient to be detected. Researchers know little about those viruses other than that they can "live longer in water than bacteria and can cause symptoms at lower densities than bacterial densities."

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