Conventional (warm air) and high-velocity (jet air) dryers alike spread bacteria into the air, according to the study. Airborne germ counts near warm-air dryers were found to be 4.5 times higher than the counts near paper towel dispensers, and the counts near jet air dryers were a whopping 27 times higher.
It doesn't take a lot to figure out what's probably going on here. As study leader Prof. Mark Wilcox, professor of medical microbiology at the University of Leeds, told The Huffington Post in an email:
"While jet air dryers are good at hand drying, they achieve this by using air velocities of about 400 miles an hour... Unfortunately, this means that the dispersed water droplets (containing more or less bacteria/viruses depending on how hands were washed and how contaminated they were in the first place) will be fired longer distances and some will remain suspended in the air for many minutes (possibly hours)."
For the study, the researchers contaminated people's hands with harmless Lactobacillis bacteria that normally aren't found in bathrooms. Then they measured levels of the bacteria in the air at distances of up to two meters away from the dryer after the people had dried their hands.
Wilcox said he had no proof that germs spread by dryers could cause illness but added that the findings suggest this "could happen. I believe that the results of our work mean that electric dryers should ideally not be installed in settings where microbe transmission is a greater risk, e.g.hospitals, cruise ships, etc."
That sounds a lot like the conclusion of a 2012 study comparing paper towels and hand dryers, which read in part: "From a hygiene standpoint, paper towels are superior to air dryers; therefore, paper towels should be recommended for use in locations in which hygiene is paramount, such as hospitals and clinics."
Of course, how you dry your hands makes little difference if you're not washing them in the first place. And according to a 2013 study, only 5 percent of people wash up properly after using the bathroom.
And some are saying the new hand dryer study is all wet.
“This research was commissioned by the paper towel industry and it's flawed," a spokesperson for dryer maker Dyson told The Telegraph.
Wilcox acknowledged that the study was funded by the European Tissue Symposium, an association of tissue paper producers. But the group "played no part in the results analysis," he said, adding that he had no ties to ETS other than the financial support for the study.
The study was published in the Journal of Hospital Infection and presented at a recent meeting of the Healthcare Infection Society in Lyon, France.
source: huffingtonpost.com By David Freeman