You may dislike the roar of electric hand dryers that line the walls of public restrooms, but you probably “get” why hand dryers are so much better than paper towels. For one, they save the environment from tons of used paper towels. And you also probably think that air-drying is more hygienic that wiping your hands on paper towels.

Well, it is certainly true that hand dryers are better for the environment, but there is actually something sinister about them—something you probably never thought of. Truth is, the potential danger of hand dryers has never been fully studied until now, and the results are alarming…

PAPER VS. AIR

A study from the University of Leeds in the United Kingdom has found that the amount of bacteria in the air around hand dryers is 27 times higher than the amount when paper towels are used instead. Making things worse, the air around the super-fast, high-velocity hand dryers that have gotten so popular lately—the dryers that make that searing, ear-piercing scream when you get your hands close to the nozzle—contains, by far, the most bacteria of all: nearly five times more bacteria than around basic hot-air hand dryers.

If you are wondering exactly how drying cleaned hands can spread bacteria, it’s pretty simple—just-washed hands aren’t as clean as you might think. There is still bacteria on them. In drying hands with a paper towel, you’ll remove some of these bacteria and throw them into the trash. In drying your hands with an electric dryer, you’ll also remove some of the bacteria, but instead of going into the trash, they’ll be thrown onto and around the dryer…onto anyone near the dryer…and also across the room up to at least one meter away.

The Leeds researchers proved this in a tightly controlled laboratory experiment, done in the way it was to avoid the bias and confusion of results found in earlier studies on hand drying. They set up air-controlled rooms in which different types of hand dryers and paper-towel dispensers were installed just as they would be in public restrooms. Rather than expose themselves to dangerous infectious bacteria for the experiment, the researchers used lactobacilli (harmless bacteria found in yogurt) to test how hand dryers and paper towels potentially spread bacteria. They wore gloves contaminated with the bacteria to imitate poorly washed hands. They then placed their hands under hand dryers or dried them with different brands of paper towels and collected air samples immediately around the dryers, on other surfaces and one meter away from where the hand drying was done.

All this means that when you dry your hands with a hand dryer in a busy public restroom, not only are you spreading your own bacteria around, you are getting blasted with the bacteria from other people who are using or have used dryers. Yuck! No wonder it’s so easy to catch colds and the flu in public spaces…and potentially worse infections (E. coli, anyone?).

ARM YOURSELF

This study didn’t go further and test infection rates (as opposed to just bacterial loads) around hand dryers versus paper towels—that’s a very complicated study to contemplate—and it isn’t clear that anyone will ever do it. No matter. The action here for personal and public health seems clear. To minimize the spread of bacteria in public restrooms, always opt for paper towels over a hand dryer if you have a choice. Because many restrooms don’t offer paper towels (or any kind of towel) anymore, carry a small supply of paper towels or paper napkins with you when you go out. Don’t forget that you can use a gel sanitizer or wipes for hand hygiene. And although you might not be able to completely avoid use of public restrooms that contain hand dryers, you can minimize your exposure to the airborne bacteria in them by not lingering to primp, groom or chat. Get outta there.