High-powered hand dryers, like those used in public restrooms, are the latest targets in pursuit of cleanliness in public and medical environments

Microbiologists and clinical laboratory scientists will be fascinated by the findings of a research study into a method of hand drying that the study scientists described as like “virus hand grenades.” If these findings are confirmed by other studies, it may lead to changes in how hand washing stations in hospitals and medical laboratories are equipped, among other things.

Clinical laboratory personnel and pathology group members come into contact with, and fight against, biological contamination on a daily basis. Proper hand-washing/drying and waste disposal techniques, therefore, are critical functions for any well-run medical laboratory. That is why it is significant to learn that today’s most common hand-drying apparatus—the Jet Air Dryer—could be responsible for spreading infections germs through its everyday usage.

After studying hand-drying techniques, researchers at The University of Westminster in London determined that high-powered jet air dryers can act like “virus hand grenades.” The study, published in the Journal of Applied Microbiology earlier this year, compared the virus-spreading capabilities of three different types of hand-drying techniques:

1.     Warm air dryers;

2.     Jet air dryers; and

3.     Paper towels.

To perform the research, participants placed MS2, an “icosahedral, positive-sense single-stranded RNA virus that infects the bacterium Escherichia coli and other members of the Enterobacteriaceae,” on their gloved hands. They then dried their hands using the various drying methods. Samples were collected around the three devices from different heights and distances on petri dishes and from the air to rate the capacity of these hand-drying devices to scatter contaminants into the surrounding environment.

Blowing Viruses Throughout the Room

The scientists discovered the jet air hand dryers could disperse viruses up to nine feet from the device. By contrast, the more commonly used and less powerful warm air dryer spewed the MS2 three feet from the machine. Paper towels were only able to disperse the virus a mere 10 inches.

Based on research originally published in the Journal of Hospital Infection, the graphic above demonstrates how the various hand-drying methods alter the spread of viruses, described by Westminster researchers. These findings will be of interest to microbiologists, pathologists and medical laboratory scientists involved in infection-control programs at their hospitals and labs. (Graphic copyright: Food Safety Consortium, Ltd.)

The type of hand dryer used for the study was the Dyson Airblade. The researchers learned that the high-powered Airblade spread 60 times more germs into the air than the lower-powered warm air dryers and scattered 1,300 more viruses than the paper towels.

Dyson criticized the study, noting that the scientists had an unusually high amount of the virus on their hands. The company also stated that while paper towels may not dispense viruses into the air, they can be polluted with germs and spread them to other people. In addition, Dyson claims on its website that “up to 88% of unused paper towels tested in the US contain bacteria, which can transfer to your hands.”

Dyson has also alleged that such studies are funded by the paper towel industry to discredit the effectiveness of their products.

Thorough Hand Washing a Critical Step

In addition to having a large amount of the virus on their hands, it is worth noting that the researchers did not attempt to wash the MS2 from their hands before using the assorted drying techniques. People typically have washed their hands with soap and water before operating any type of hand dryer or wiping their hands with paper towels. Although it is debatable which hand-drying method is the most hygienic, obviously the best practice is to thoroughly wash hands and dry them with whatever hand-dryer is available.

Hand hygiene is widely known to be a crucial element in minimizing the transmission of pathogenic micro-organisms that can cause infections. According to the Westminster study, “it has been estimated that cross-infection contributes to 40% of cases of healthcare-associated infections and hand hygiene compliance represents an essential step in minimizing such infections.”

Choosing Best Hand Dryer for Medical Environments, Clinical Laboratories

The researchers noted that, “the choice of hand-drying device should be considered carefully in areas where infection prevention concerns are paramount, such as healthcare settings and the food industry.”

In the past, microbiologists have performed studies where they have swabbed the hands of medical staff, equipment, and surfaces to demonstrate the presence of infectious agents. One study even examined doctors’ neckties and found the existence of bacteria that can cause infections, such as:

·       Klebsiella pneumoniae;

·       Pseudomonas aeruginosa;

·       Staphylococcus aureus; and

·       Aspergillus fungus.

In 2013, Weill Cornell Medical College launched PathoMap to study genetic material in the New York City Subway System. Their objective was to establish a molecular view of the city to positively impact public health.

Weill researchers discovered genetic material from more than 15,000 species among 1,400 samples collected from 468 subway stations. The material was mostly harmless or unidentified.

PathoMap recently implemented MetaSUB, which stands for “Metagenomics and Metadesign of Subways and Urban Biomes,” to perform similar studies of mass-transit systems in 39 cities on six continents. The goal is to help city planners, public health officials, and designers create healthier environments.

Whether “virus hand grenades” are fact or myth, targeted research such as the studies above highlight the critical need for clinical laboratories and other medical practices to understand how the devices used in hand washing and hand drying contribute to improved hygiene and lower infection rates that help protect patients as well as physicians, nurses, medical laboratory scientists, and other healthcare workers.

—JP Schlingman

Related Information:

Study: ‘Jet’ Hand Dryers Act Like Virus Hand Grenades

Hand Dryer vs. Paper Towel: Which Is Cleaner?

Comparison of Different Hand-Drying Methods: The Potential for Airborne Microbe Dispersal and Contamination

Dyson Hand Dryers Spread More Germs than Paper Towels, Study Says

Do Jet Hand Dryers Really Spread More Germs than Paper Towels?

Evaluation of the Potential for Virus Dispersal During Hand Drying: A Comparison of Three Methods

Study Finds Doctors’ Neckties Carry Pathogens

There are 15,000 Lifeforms Riding the NYC Subway, Including Meningitis

Up To 88% of Unused Paper Towels Tested in the US Contain Bacteria, Which Can Transfer to Your Hands

Other Hand Dryers Can Blow Viruses and Bacteria onto Your Hands, Some of It from Feces

Microbiologists at Weill Cornell Use Next-Generation Gene Sequencing to Map the Microbiome of New York City Subways