“These results indicate that many kinds of bacteria, including potential pathogens and spores, can be deposited on hands exposed to bathroom hand dryers,” they wrote, “and that spores could be dispersed throughout buildings and deposited on hands by hand dryers.”
As the dryers blast out air, they also suck up bacteria from the bathroom, which can fester inside the device and be blown out onto the hands. The germs can then travel between rooms of a large building.
Therefore, they concluded that the use of “hand dryers is a possible mechanism for spread of infectious bacteria including spores of potential pathogens if present.”
The scientists have also explored the capabilities of high-efficiency particulate air (HEPA) filters. While they were able to block out 75 percent of the bacteria, they have added paper towels to all of the bathrooms included in their investigation.