Study Targets Link Between Hand Dryers And Bacteria

A recent Facebook post of a bacteria-ridden petri dish went viral — being shared more than 570,000 times — when viewers realized it's contents were collected from a restroom hand dryer. Reportedly, the open plate was placed in an enclosed hand dryer of a public restroom for three minutes and the results were photographed for everyone to see.

Little in terms of details was revealed about the findings, which sparked additional hand dryer studies from reliable sources.

Forbes recently reported on such a study, published in Applied and Environmental Microbiology and conducted by officials at the University of Connecticut Health and Quinnipiac University. The team brought bacteria culture plates into 36 men's and women's restrooms in an academic health center and exposed them to hot air driers for 30 seconds.

Following the exposure to the dryers, researchers found an average of 18 to 60 colonies of bacteria on each plate. This is compared to the two-minute tests done in restrooms where no air dryers were running and where an average of 1 or less colonies were found on each plate.

Reports indicate that installing HEPA (high efficiency particulate air) filters into the dryers did help reduce the amount of bacteria being spread. Researchers found four-times less bacteria in the use of these dryers.

According to Forbes, the results from this study mirror those done by other researchers recently. A study published in the Saudi Journal of Biological Sciences found an array of bacteria from 15 different air dryers.

And a separate study published in the Journal of Hospital Infection didn't just look at hot/warm air dryers, but compared them with jet air dryers and paper towels. When the jet dryer was used, 4.5-times more bacteria was spewed into the air than when a warm air dryer was used, and 27-times more bacteria was spewed than when paper towels were used.