Hand Dryers May be Spreading Bacteria in Public Bathrooms

First Posted: Nov 20, 2014 10:47 AM EST

A hand dryer may be cost effective and save some trash, but it could be a lot worse when it comes to spreading germs. Scientists have taken a closer look at hand dryers in bathrooms and have found that when it comes to drying your hands, you may want to stick with paper towels.

In order to see whether bacteria could be spread with the use of air dryers, the scientists contaminated hands with a harmless type of bacteria called Lactobacillus, which is not normally found in public bathrooms and mimicked poorly-washed hands. They then tested the effects of hand dryers versus paper towels on the spread of this bacteria.

In the end, the researchers detected Lactobacillus in the air. This suggested that it must have become airborne from a person's hands during drying. In fact, the scientists found that air bacterial counts close to jet air dryers were 4.5 times higher than around warm air dryers and 27 times higher compared with the air when using paper towels. In addition, next to dryers the bacteria persisted in the air well beyond the 15 second air drying time, with approximately half of the Lactobacilli collected more than five minutes after drying ended.

"Next time you dry your hands in a public toilet using an electric hand dryer, you may be spreading bacteria without knowing it," said Mark Wilcox, one of the researchers, in a news release. "You may also be splattered with 'bugs from other people's hand. These findings are important for understanding the ways in which bacteria spread, with the potential to transmit illness and disease."

While hand dryers are useful, they could also be impacting public health. It's important to take these factors into account when designing public bathrooms, especially when there is risk for bacterial spread-especially in locations such as hospitals.

The findings are published in the Journal of Hospital Infection.

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