CHICAGO (Reuters) - Americans' hands are getting dirtier, U.S. researchers said on Monday.
They said 77 percent of more than 6,000 men and women washed their hands in public restrooms -- a 6 percent decline compared with a similar study in 2005.
According to the U.S. Centers for Disease Control and Prevention, handwashing in the single-most important prevention step for reducing disease transmission.
In a telephone survey, 92 percent of adults said they wash their hands in public conveniences, according to the study done by the American Society for Microbiology and The Soap and Detergent Association.
But the study, which also conducted research at public restrooms, showed people's actions were not always matching their claims.
Men were the biggest offenders, with just 66 percent of men seen washing their hands in public bathrooms, compared with 88 percent of the women, according to study presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy meeting in Chicago.
"Very clearly, guys need to step up to the sink," said Brian Sansoni, a spokesman for the soap industry group, told reporters. "One third of guys weren't washing their hands in public restrooms. That's gross."
Researchers staked out restrooms at different types of venues in four U.S. cities: Chicago's Shedd Aquarium and the Museum of Science and Industry, Atlanta's Turner Field, New York's Grand Central Station and Penn Station and San Francisco's Ferry Terminal Farmer's Market.
Men's hygiene was worst at Atlanta's Turner Field, where just 57 percent of men were observed washing their hands after using the toilet at the baseball venue. But 95 percent of women there washed their hands, the highest percentage observed in the study.
Chicago was the city with the cleanest hands overall. New York was the second-cleanest, Atlanta came in third, and then San Francisco.
While handwashing trends in public toilets appear to be on the decline, the more than 1,000 men and women surveyed by telephone in the study reported virtually no change in their habits.
The researchers could not account for why people appear to be washing their hands less in public bathrooms. And they admitted that because the research was done in different venues, it was not scientifically valid.
But they said the trend is troubling.
"Fifteen to 20 seconds of friction and soap and water will remove so many germs from your hands and help with your wellbeing. That is a marvellous intervention that will work all over the world," Judy Daly, director of the Microbiology Laboratories at the Primary Children's Medical Center in Salt Lake City, Utah, told reporters.