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 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 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, 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 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 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 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, 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
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 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 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 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.
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 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 Works dot Com, and it's produced by Tyler Clang. Four more podcasts my heart Radio, visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.