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Wash your hands.

Here's the drill: Scrub vigorously with water and soap until lather appears, making sure to get between your fingers and fingernails. Use a nail brush if you have one. Briskly dry with a towel.

Do it often and you'll stay a lot healthier — 24 percent less like to get a respiratory illness and 45 percent to 50 percent less likely to get a stomach bug, said the World Health Organization.

Hand washing "has a huge health impact," said Anna Bowen, an epidemiologist at the Centers for Disease Control and Prevention in Atlanta. Water is not the most important part, it's "the friction and duration," she said. "You really need to scrub vigorously for about 20 seconds."

Still not convinced?

"Eighty percent of infections are transported by touch, so hand washing is the number one thing you can to do prevent infection," said Michael Smith, WebMD's chief medical editor in Atlanta.

And not just when you're leaving the restroom.

"Take the opportunity to take a hand washing break," Smith said. "Any time you're touching something that other people frequently touch, it's a good time to wash your hands."

Not that we do. According to an American Society for Microbiology survey, 91 percent of Americans said they always washed after using a public restroom. But when researchers actually watched, it turned out only 83 percent did.

Barely. When people wash their hands, only 33 percent use soap and only 16 percent adequately wash. The average hand washing time was a pathetic 11 seconds, said Charles Peter Gerba, an environmental microbiologist at the University of Arizona in Tucson.

Popular alcohol hand gels aren't as effective as soap and water but they're better than nothing, Smith said.

Soap and water help dislodge dirt, bacteria and viruses so they "can go down the drain," he said. With gels, "the bacteria has nowhere to go."

On the other hand, don't buy the antibacterial soap hype. There's little evidence it's any more effective.

Paper or blower?
Then there's the question of how to dry newly washed hands.

Air dryers first became popular in the 1970s, developed to reduce paper usage, save energy and cut maintenance costs. But consumers didn't like them, and today they're in only 6 percent of U.S. public restrooms, according to the consumer research company Mintel.

Which works better, paper towels or dryers, is hotly debated.

Doug Powell, a professor of food safety at Kansas State University in Manhattan, Kan., said numerous papers show that the friction created by using paper towels is actually a key part of the cleaning process. The friction "removes the bacteria, whereas blow dryers tend to disperse them in the air," he said.

However, a study done by the Mayo Clinic in 2000 found that four potential drying methods, paper towel, cloth roller towel, warm forced-air dryer and "spontaneous room air evaporation," were all about equal in terms of removing bacteria.

A study done at Rutgers found that forced-air drying left slightly more bacteria on hands, while paper towels left slightly less.

Do warm forced-air dryers breed bacteria, spewing it back over clean hands? Some research has found bacteria colonizing in the machines, though the findings are flatly denied by the hand dryer industry.

A mighty wind
Then there's the question of whether blowers actually get hands dry. A study done at the University of Westminster in England in 1993 found that because of the time they took, people generally got their hands to only 55 percent-65 percent dryness before giving up, which made possible cross-contamination later more likely.

There's also anecdotal evidence that people simply don't wash when they see blow dryers because they take so long. "People are busy" and don't want to take the time, said Herbert DuPont, an infectious disease researcher at the University of Texas School of Public Health.

Still, it's better to wash your hands and then dry them on your pants than not to wash them at all, said the CDC's Bowen. She did research in Karachi, Pakistan, which found that even when people used their clothing to dry their hands, there was still a 50 percent reduction in the rate of respiratory and diarrheal illnesses.

All of which may be moot with the coming of high-velocity hand dryers that take just seconds.

Two years ago Mel Schiavelli, president of Harrisburg University of Science and Technology in Pennsylvania, saw an example in the Time-Life building in New York City. Made by the Dyson vacuum company, they blow a stream of room-temperature air over hands at 400 mph, drying them in less than 12 seconds.

Schiavelli was literally blown away. "They put out this incredible wind," he said. The university just opened a new technology building to house 1,000 people and he has had them installed in every bathroom.

Though there's one thing a blower can't do: It can't be used to open a bathroom door that has been opened by dozens of people who didn't wash their hands.

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