In 2014, a team of researchers from the University of Leeds dropped a disturbing truth bomb on the public by announcing that the no-touch jet-air dryers in public restrooms are anything but sanitary. They found that these increasingly popular devices blast bacteria from people’s poorly washed hands (most people don’t wash their hands correctly) into the air and onto nearby surfaces in disturbing quantities, increasing the likelihood that you'll walk out of the bathroom covered in other people's germs.
In lab-based experiments recreating a public washroom, jet-air dryers introduced 27 times more bacteria into the air than good-old-fashioned paper towels, and these microbes circulated for 15 minutes afterward.
Now, the authors are back with even more evidence against hand dryers, this time from real-world experiments.
As reported in the Journal of Hospital Infection, Professor Mark Wilcox and his colleagues set out to examine how hand drying methods affect bacterial spread in hospital bathrooms – an important issue because many serious and antibiotic-resistant infections are known to circulate in clinical settings.
The investigation was conducted in hospitals in three cities – Leeds, Paris, and Udine, Italy – over a 12-week period. For each location, two restrooms used by patients, staff, and visitors were selected, and each was set up to offer only a jet dryer or paper towels. Samples of the air and swabs of restroom surfaces were taken every day for four weeks, then, after a two-week pause in collections, each restroom switched to offer the alternate drying method. This process was then repeated a third time.
Cultures from these samples revealed that the total amount of bacteria in the air and on surfaces was consistently much higher in all restrooms when jet dryers were being used. The most dramatic differences were seen between the surface of the jet dryer itself and the surface of the paper towel dispenser: In Udine, the dryer was covered in 100 times more bacteria, in Paris it was 33-fold higher, and in Leeds it was 22-fold.
In the UK restrooms, the notorious methicillin-resistant Staphylococcus aureus (MRSA) bacterium was found three times more frequently during jet dryer usage periods than paper towel periods. Bacterial species resistant to both penicillins and cephalosporins (known as ESBL-producing organisms) and species of pathogenic enterococci – a difficult-to-treat group – were found in significantly higher frequency and counts during these periods as well.
In the Parisian and Italian hospitals, few pathogenic or drug-resistant bacteria were encountered during either hand drying set-up.
“Consequently, we believe that electric hand dryers are not suited to clinical settings, and, as such, existing (e.g. NHS) infection control building guidance needs to be amended and strengthened,” Wilcox’s team wrote, adding that there is little justification for their use in any public setting given the risks they present.
Based on the earlier research, French health officials recently updated their guidelines to discourage use of hand dryers in clinical wards. UK hospitals currently discourage their use in such areas as well, but the reasoning is based on noise concerns. There are no provisions against using them in public-facing reception areas in either country, and no restrictions at all in the US.
“The problem starts because some people do not wash their hands properly,” Wilcox explained. “In effect, the dryer creates an aerosol that contaminates the toilet room, including the dryer itself and potentially the sinks, floor and other surfaces, depending on the dryer design and where it is sited.
“However, paper towels absorb the water and microbes left on the hands and if they are disposed of properly, there is less potential for cross-contamination.”