Back in 2014, a team of researchers at the University of Leeds found out that jet air dryers, contrary to being sanitary, are actually fantastic at spewing bacteria all over public restrooms, increasing the likelihood that you’ll walk out of them awash in other people’s germs. Lovely.
The lab-based experiments replicated a public washroom and found that jet air dryers introduced 27 times more bacteria into the air than paper towels did. What’s more is that these microbes circulated in the air for 15 minutes afterward.
The researchers have now come out with even more evidence against hand dryers. The only difference is that this time, they conducted their experiments in the real world. They set out to examine how hand drying methods affected bacterial spreads in hospital bathrooms due to the many serious and antibiotic-resistant infections that circulate in clinical settings.
Hospitals in Leeds, UK, Paris, France, and Udine, Italy were used for the investigations, which were conducted over a 12-week period. Two restrooms used by patients, staff, and visitors in each hospital were selected, and each was set up to offer only a jet dryer or paper towels. Samples from the restrooms were taken every day for four weeks, then there was a two-week pause in the experiment before the drying methods were alternated. The whole process was then repeated for the third time.
In their findings, the researchers saw that the total amount of bacteria both in the air and on surfaces was far higher in restrooms where jet air dryers were being used. Even more disturbingly, UK restrooms were found to have three times the amount of Staphylococcus aureus bacterium than in the other hospitals tested during the period when jet air dryers were in use.
Bacterial species that are both penicillin- and cephalosporin-resistant were also found to be present in significantly higher quantities when jet air dryers were being used. “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,” said the lead researcher.
“The problem starts because some people do not wash their hands properly,” the lead researcher added. “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.”
BONUS - Check out this Sky News report referencing this study: