The next time you reach out to shake someone's hand, consider this: A recent study of hand-washing found only 5 percent of people who used the restroom scrubbed long enough to kill germs that can cause infections.
Thirty-three percent didn't use soap, and 10 percent didn't wash their hands at all, according to the study, based on Michigan State University researchers' observations of more than 3,700 people in a college town's public restrooms.
"These findings were surprising to us because past research suggested that proper hand washing is occurring at a much higher rate," said lead investigator Carl Borchgrevink, an associate professor of hospitality business.
Among the other findings:
- Men were less likely than women to clean their hands. Fifteen percent of men and 7 percent of women didn't wash their hands at all. When they did wash their hands, only 50 percent of men used soap, compared with 78 percent of women.
- People were less likely to wash their hands if the sink was dirty.
- People were more likely to wash their hands earlier in the day. This may be because when people are out at night for a meal or drinks, they are relaxed and hand washing becomes less important, the researchers suggested.
- People were more likely to wash their hands if they saw a sign encouraging them to do so.
- Hand washing is the single most effective thing a person can do to reduce the spread of infectious diseases, according to the U.S. Centers for Disease Control and Prevention. Failure to sufficiently wash hands contributes to nearly 50 percent of all foodborne illness outbreaks, the agency says.
Here's how to do it right: Use soap, scrub well (including the backs of your hands, between your fingers, and under your nails) for at least 20 seconds, and dry your hands afterward. People only wash their hands for an average of 6 seconds, according to the study, published recently in the Journal of Environmental Health.
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