The germs that lurk in hand dryers are revealed by experiment

How often do you use hand dryers in public restrooms to dry your hands or your kid’s? Quite often, I’d imagine. Have you ever thought of the possibility of germs in hand dryers? If you have, the results of a recent experiment will shock you.

Nicole Ward is a nursing student, and her microbiology professor gave her class the following assignment: choose a location, open a petri dish for three minutes, and observe what grows in it over two days.

When Ward returned to class with a petri dish she exposed under a hand dryer in a women’s restroom, the result was shocking. The colonies of fungi and bacteria that grew in it surpassed anything that her classmates brought.

In an interview with the New York Times, she said “Mine just had so much more mass in the fungal growth. Their [her classmates’] little colonies were just a speck here and a speck there. It just stood out by far.”

As far as we know, that was the end of it. No further tests were done on what the students have found, so we can’t tell whether what Ward found is harmful to humans.

News of  what Ward discovered blew up on social media when she posted a photo of her petri dish on Facebook at the insistence of her classmates. More than 577,791 people have shared the photo as of this writing.

Many of the horrified comments on the post are oaths never to use a hand dryer ever again. Some others ridiculed the post as unscientific fear-mongering. Ward even received, of all things, death threats.

Hand dryer dispute. Photo by Shutter Stock

Scientists still widely dispute the issue of pathogens and germs in hand dryers.

“The hot air will kill the bacteria on the hands, but some studies have found they will also deposit bacteria in the restroom on your hands — i.e., from the air,” says Charles P. Gerba, a microbiologist at the University of Arizona.

Meanwhile, a study published in 2016 in The Journal of Applied Microbiology looked into jet air dryers similar to what Ward used. It found that they contaminate their surrounding area with 1,300 times as many viral particles as a paper towel would.

In another similar study in 2014, which focuses on a bacterium instead of a virus, researchers found that jet air dryers spread 4.5 times as much bacteria as warm air dryers, and 27 times as much bacteria as paper towels. It has to be noted though that a trade association of paper manufacturers funded the study, so it’s possibly biased towards paper towels.

Ward’s advice? In the comments section of her post she said, “From now on I just wash and scrub, and dry on my clothes or shake and air dry OUTSIDE of the [restroom].”

Mums and dads, there’s no doubt that hand hygiene in kids is really important. But we think you might want to avoid hand dryers in public restrooms after reading this article and just bring your own pack of tissues to dry those little hands!

Sources: The New York Times, Facebook, Kidspot

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