The results were published this month in the journal Applied and Environmental Microbiology. "And there are a lot of bacteria in bathrooms".
A new study has found a dirty little secret about hand dryers found in many public restrooms.
Hand dryers suck up bathroom air and spew it out at speed.
What's unclear, they admit, is just why the air-blasted plates showed so many more spores.
A hand is illuminated.
The study examined 36 bathrooms at the University of Connecticut School of Medicine, testing each machine during a single drying session. The dryers blew up to 60 separate bacterial colonies, including staphylococcus aureus, a common bodily bacteria that's been associated with infections, CBS Pittsburgh reports.
In theory, adding high-efficiency particulate air (HEPA) filters should stop bacteria particles from spraying over your newly cleaned hands. These results indicate that many kinds of bacteria, including potential pathogens and spores, can be deposited on hands exposed to bathroom hand dryers and that spores could be dispersed throughout buildings and deposited on hands by hand dryers. However, when the team retrofitted some of their dryers with HEPA filters, they only blocked about 75 percent of bacteria. Researchers say the machines, which are created to blow hot air on you, are actually sucking up feces particles and spraying them onto your hands. Convection created by a hand dryer's air streams, for example, might pull in unfiltered bathroom air.
Hot-air hand dryers in multiple men's and women's bathrooms in three basic science research areas in an academic health center were screened for their deposition on plates of (i) total bacteria, some of which were identified, and (ii) a kanamycin-resistant Bacillus subtilis strain, PS533, spores of which are produced in large amounts in one basic science research laboratory.
Regardless, as Newsweek reported, study author Peter Setlow perfers paper towels, which are now stocked at all 36 bathrooms used in the study.