The question is how sanitary are hand dryers. Washing your hands is important. In fact, the World Health Organization estimates that something as “inconsequential” as washing your hands reduces your chances of getting respiratory illnesses and up to 50% your stomachs by 24%. This has been repeated to satiety.
What is not said so often is that as important as washing your hands is drying them well. Moreover, a recent study from the University of Connecticut has just shown that, if we use hot air hand dryers, hand washing is probably not helpful.
A solution that leaves much to be desired
Published in Applied and Environmental Microbiology, researchers have shown that hot air dryers absorb bacteria and bacterial spores and throw them directly into freshly cleaned hands. It is not something that catches us by surprise, of course. As Ken Jennings explained,
A 2008 study conducted at a university in London determined that there is also an incorrect way to dry your hands.
Those electric dryers that heat the air doubled, in fact, the number of bacteria in the hands of the subjects during the drying process, and those new models of jet air injection, those that supposedly throw a jet to the hands at a speed of 650 kilometers per hour, they were able to release the germs of the hands two meters around the apparatus.
Instead, those paper towels that seem so outdated absorbed 76 percent of all bacteria and did not spread anything.
To find out, the researchers left Petri dishes open under air jets. In just 18 hours, the plaques developed six bacterial colonies on average. According to estimates, crowded bathrooms could project more than 200 bacteria every 30 seconds.
A vector of potential infections
It is not clear what is the mechanism that turns the dryers into a germ dispersion focus, but everything seems to indicate that it is the large amount of air that passes through these systems and that it causes a huge circulation inside the room collecting the bacteria that toilets have projected into the air.
The researchers discovered the problem was partially solved with filters (levels were reduced up to four times), but the data is worrying enough to eliminate them from sensitive spaces such as health centers and laboratories where infectious diseases are investigated.
Without going any further, the University of Connecticut (where research has been developed) has replaced the dryers with paper towel dispensers in 36 bathrooms of the School of Medicine (and its research areas).
Anyway, it is not usual that this is a problem: only in spaces such as hospitals or laboratories, it seems advisable to replace them right now. But these data should make us reflect on how to wash our hands.
Read also: Best Hand Dryers on the Market