Washing our hands with safe water and plenty of soap is the first recommendation we hear in almost every disease prevention campaign, such as the flu. However, simply pressing the button of a hand dryer in a public bathroom can throw that prevention down the drain. The idea of the hand dryer as a "bacterial bomb" has been around for several years, and now a new study published by researchers at the University of Connecticut confirms its ability to distribute bacteria, including those that did not originate in bathrooms.
The Hidden Cost of Hand Dryers
You finish pondering the mysteries of the universe on the throne, wash your hands, go to the hot air dryer (because it's the only option available) and press the button. The beast leaves you dry in seconds, and beyond the noise (some units are an assault on the ears) it doesn't feel so bad, but that's not the goal behind its existence, but to save money. Dryer manufacturers have shared data suggesting thousands of dollars spent per year on disposable towels, while a hand dryer requires only a fraction of that cost in electricity. At the same time, dryers are presented as a more "ecological" alternative because they don't consume paper, but by solving one problem they created another: Hand dryers are the ultimate bacteria distributors.
The University of Connecticut Study
A recent study from the University of Connecticut reveals that researchers placed several agar plates in the university's bathrooms for two minutes with "still" air, and exposed to the dryer for 30 seconds at 30 centimeters from the nozzle. In the first case, they found that the average colony formation was between 0 and 1, while the dryers' blast raised it to between 18 and 60 colonies per plate. The installation of filters with HEPA characteristics in the dryers managed to reduce the bacterial count fourfold, and a detail to keep in mind is that some of the germs did not originate from the dryer nozzles, but in the bathrooms and their surroundings, since they obtained similar results by installing small sterilized fans to move the air.
A Disturbing Discovery
That leads us to what is probably the most disturbing aspect: The researchers discovered traces of the bacterium Bacillus subtilis PS533, a laboratory strain resistant to kanamycin. The key word here is "laboratory": The bathrooms used in the study were near a space focused on analyzing B. subtilis PS533. The dryers managed to spread the PS533 spores, and its presence was detected even in bathrooms that did not share a building with the lab in question. This is an alarm signal for all those facilities that must limit bacterial contamination.
