Hand dryers spread much more bacteria than paper towels in a public bathroom setting, according to research from the University of Leeds.
To conduct the experiment, researchers contaminated hands with harmless bacteria not usually found in public restrooms, Lactobacillus. Then, when that bacterium was found in the air, it could be tied to the hands. They conducted air samples around hand dryers and paper towel dispensers.
For jet dryers, air bacteria counts were 4.5 times higher than around warm air dryers and 27 times higher compared to air when paper towels were used. Additionally, bacteria stayed in the air beyond the 15 second dry time around the dryers, with 48 percent of the bacteria collected more than five minutes after drying ended.
"These findings are important for understanding the ways in which bacteria spread, with the potential to transmit illness and disease," said Professor Mark Wilcox, with the University of Leeds' School of Medicine.