Do Hand Dryers Really Spread Germs?

Some studies warn against using those air-blasting hand dryers in public bathrooms, but the results are complicated. Learn more (including why a good wash is most important) in this episode of BrainStuff, based on this article: https://health.howstuffworks.com/diseases-conditions/infectious/jet-hand-dryers-blast-viruses-germs.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,
Lauren volgabam Here. The last thing people want in a
public restroom is more germs, But depending on how they
wash and dry their hands, that maybe exactly what they're spreading.
There's a large vein of research studying the effects of

(00:23):
hand washing, hand drying, and germs, and the results are
complicated and take. A study published in the journal Applied
and Environmental Microbiology, the authors found, after studying samples collected
from both ambient bathroom air and air dryer blown bathroom air,
and that because hand dryers suck in the air in

(00:44):
a restroom which is full of constantly circulating microbes and debris,
and then spew it out at a high velocity, they
actually expose people to more microbes. The researchers exposed both
types of air to petree dishes and found out that
when the hand dryers weren't running, only six bacterial colonies grew,

(01:05):
but when the dryers were running, the total number of
colonies grew to as many as sixty per plate, and
included strains of staff that are capable of causing serious infection.
Another study published in twenty fifteen in the Journal of
Applied Microbiology compared different hand drying methods and their effect
on germ dispersal. The researchers discovered that those vertical jet

(01:27):
air dryers can actually spread viruses across a distance of
nearly ten ft or three meters. The jet air dryers
are activated when a person vertically inserts their hands inside
the machine, causing powerful air jets to turn on. However,
the researchers found that these air jets spread viral plaques,
which are groups of clumped viruses, at a rate of

(01:49):
one thousand, three hundred times more than paper towels. The
study did not investigate the distribution of bacteria, which are
bigger than viruses. The findings were recorded after participants dipped
gloved hands into a solution with an innocuous virus. Participants
then shook excess liquid off their gloves and used one
of three drying methods paper towels, warm air dryers, and

(02:12):
jet dryers. The researchers then collected air samples at a
variety of distances from each type of dryer. They also
used petree dishes to collect viruses that landed on surfaces
adjacent to the drawing stations. In the end. The jet
air dryer spread viruses the farthest, so that sounds bad,

(02:33):
but not so fast, says Dyson, the company that makes
the popular air Blade jet air dryers. In two thousand eight,
the Dyson jet air dryer was the first such product
to earn accreditation from the Royal Society for Public Health.
Dyson argues that other research from found that upcent of
fresh yet unused paper towels tested in the US contained

(02:55):
bacteria which can transfer to hands. Dyson also contends that
the Journal of Applied Microbiology study artificially inflated germ concentrations.
In real life situations, the company says most people would
not have the sheer number of viruses on their hands
as was used in the study, nor would they stick
their unwashed, virus coated hands into a jet dryer without

(03:17):
rinsing and cleaning first. So what's the best course of
action for hand washers? Even the professionals are debating the issue.
A study published an Infection Control and Hospital Epidemiology in
compared the three step handwashing method outlined by the US
Centers for Disease Control and Prevention or CDC to the

(03:38):
six step strategy of the World Health organization. The study,
which observed doctors and nurses using both of these hand
washing techniques, found the six step method got rid of
more bacteria. This method includes using an alcohol based hand rub.
The CDC has since changed the recommendation from the three
step handwashing process to a five step protocol. The issue

(04:02):
of compliance when implementing the six step process came up
during the study, though for the article this episode is
based on how Stuff Works. Spoke with Jackie Riley, these
studies lead author. She said only of providers completed the
entire hand hygiene process, despite participants having instructions on the
technique in front of them and having their technique observed.

(04:23):
This warrants for their investigation. Taking all of this into
consideration for now, I'd say that everyone washing their hands
properly in the first place is perhaps more important than
which drying method is used afterwards. As we all learned
at the beginning of the COVID pandemic, that's wetting your
hands and rubbing all of your hand surfaces, including the

(04:43):
fingertips and nails, with soap for at least twenty seconds
or two rounds of Happy Birthday. Today's episode is based
on the article Hand jet, hand dryers, really blast out
a germ cloud? Well, yes and no on how Stuffworks
dot Com, written by Laurie L. Dove. Brain Stuff is
production of I Heart Radio in partnership with how stuff

(05:05):
Works dot Com, and it's produced by Tyler Clang. Four
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