Reality check: Are hand dryers in public bathrooms full of bacteria and fungi? – National
A woman is warning others to be wary of public bathroom hand dryers after an experiment she conducted showed a buildup of bacteria and fungi in the machines.
Nichole Ward of California posted a photo to her Facebook account of a petri dish full of bacteria and fungi. She claims she picked up the stuff from a hand dryer. That photo has now gone viral.
“This here is what grew in a petri dish after just a few days,” Ward wrote on Facebook. “DO NOT EVER dry your hands in those things again. This is the several strains of possible pathogenic fungi and bacteria that you’re swirling around your hands, and you think you’re walking out with clean hands.”
It’s unclear what Ward’s scientific background is.
Ward posted the message in late January and it has since been shared over 545,000 times, and it’s a discovery that has many talking.
“Ahh! I just used one of those today and on it, it says ‘the most hygienic’ and all I could wonder is what about the air it blows into your face which is contaminated air in the bathroom,” Darby Toth commented on Facebook.
“So freaking nasty!” Krystle Henderson said. “Never using one of those blowers again.”
Ward says she stuck the dish in a Dyson Airblade. Dyson provided a statement to ABC Action News addressing the findings.
“We’re very surprised to see these results, and unclear on the methodology employed,” Dyson said. “All Dyson AirbladeTM hand dryers have HEPA filters that capture particles as small as bacteria from the washroom air before it leaves the machine. Dyson AirbladeTM hand dryers are proven hygienic by university research and are trusted by hospitals, food manufacturers and business worldwide.”
While the photo may seem alarming, Jason Tetro, a Canadian microbiologist and a visiting scientist at the University of Guelph, says people shouldn’t get caught up in the hype of the photo.
“[It] looks like from that whole three-minute dryer experience, she picked up a total of about five or six bacteria or fungal spores, most likely from the environment around her rather than from the dyer itself,” he says. “It just looks cross because they were growing for 48 hours on very rich media, which is enough to make some pretty giant colonies.”
With that being said, however, Tetro says that any surface has the ability to carry bacteria and fungal spores, so this shouldn’t be a surprise.
“Most of them won’t be harmful in the concentrations she found in the washroom,” he says. “Remember, it’s not the size of the colony that matters, just the number found.”
In order for the bacteria and fungi to be truly harmful, Tetro says the plate would have to be covered with colonies, but it is not as there are only a few that have overgrown.
There is also no difference in terms of hand hygiene when it comes to towels versus air dryers either, he adds. However, paper towels have consistently shown they are superior to air dryers when it comes to preventing the spread of pathogens like the flu.
Bottom line: don’t buy into the hype – there is no reason to worry about using hand dryers, Tetro says.
“If you are concerned about those few colonies, the best option is to have some alcohol-based hand sanitizer with you,” he says. “Use one with 62 per cent to 70 per cent ethanol and add enough to keep your hands wet for 15 seconds and you’ll be safe.”
© 2018 Global News, a division of Corus Entertainment Inc.