Vigorous handwashing with soap has become a compulsory part of everyone’s lives. Now, hopefully, you were washing your hands long before the coronavirus appeared, but it’s safe to say that we’re all standing in front of the sink a whole lot more than in 2019. For all of the current containment measures, from social distancing to face masks, washing one’s hands is perhaps the simplest and most effective of them all. Hand sanitizers have become like liquid gold, but nothing works quite as well at neutralizing SARS-CoV-2 like some good old fashioned soap and water.
The act of washing one’s hands is simple enough, but what about afterward? Many public bathrooms offer a choice between paper towels or jet air dryers. Paper towels are definitely worse for the environment, but a fascinating new study has concluded that paper towels are the way to go in terms of removing any lingering viral microbes.
The study, conducted primarily by researchers from the University of Leeds, simulated situations in which individuals didn’t properly wash their hands thoroughly. Still, though, these findings are probably helpful to keep in mind each time one uses a public bathroom, even if they’ve washed their hands with soap for 20-30 seconds.
The importance of proper hand hygiene can’t be overstated during this pandemic. Our hands connect us with the world around us, and a hand housing SARS-CoV-2 can spread the deadly virus to nearby tables, surfaces, counters, etc. The research team behind this study set out to determine if air dryers and paper towels result in different outcomes when it comes to the spread of viral microbes after using a public bathroom.
Admittedly, the research was quite small; four participants took part in the study. Each person had their hands covered in a bacteriophage, which is a type of virus that only infects bacteria and is harmless to humans. After their hands went viral, participants purposely didn’t wash them at all. This was done to simulate doing a poor job of washing one’s hands after coming into contact with a virus such as SARS-CoV-2.
Participants’ hands were then “dried” using either paper towels or a jet air dryer. The subjects also wore aprons to facilitate measurements of any bodily or clothing contamination during hand drying. All of this took place in a real hospital’s public bathroom, and after participants had left the hospital surfaces and areas they came in contact with were examined to see if the virus had spread.
A variety of surfaces and objects were evaluated after coming into contact with either the participants’ hands directly or their bodies. Examples include doors, stairway handrails, elevator buttons, chairs, phones, medical equipment, and the aprons themselves. In all, 11 surfaces were tested.
Both hand drying methods significantly reduced viral contamination on participants’ hands, but paper towels proved to be more effective across the board.
In 10 out of 11 tested surfaces, participants who dried their hands with a jet dryer ended up contaminating the areas to a much greater extent than those who dried their hands with a paper towel. Additionally, all surfaces showed phage (bacterial viruses) contamination after being touched following jet dryer use, while only six surfaces touched after using a paper towel were contaminated.
On average, surface contamination was 10 times higher after jet dryer use in comparison to paper towel use, and viral spread to aprons and clothes was five times higher after using a hand dryer.
While their hands and aprons were contaminated, participants were also asked to cross their arms across their chest (so their arms would touch the apron) and then sit down and rest their arms on a chair. Subsequent examination of those chairs revealed the presence of phage only among participants who had dried their hands using an air dryer. The study’s authors say this indicates viruses like SARS-CoV-2 are capable of jumping from surface to surface. For example, in this case, the virus was first on a subject’s hands, then it spread to their apron as they were drying their hands, moved on to their forearms, and then made its way to the chair.
“There are clear differences, according to hand drying method, in the residual microbial contamination of the subject’s hands and body. Crucially, these differences in contamination translate into significantly greater levels of microbe contamination after jet air drying versus paper towel use from hands and body beyond the toilet/washroom,” the study reads. “As public toilets are used by patients, visitors and staff, the hand drying method chosen has the potential to increase (using jet dryers) or reduce (using paper towels) pathogen transmission in hospital settings.”
All in all, the study’s findings are clear; paper towels are much better at removing the coronavirus than air dryers. Now, as long as you do a thorough job of washing your hands it shouldn’t matter how you choose to dry them, but opting for a paper towel is just another way to ensure you’re doing as much as possible to avoid contracting or spreading SARS-CoV-2.
“We believe that our results are relevant to the control of the novel coronavirus that is spreading at pace worldwide. Paper towels should be the preferred way to dry hands after washing and so reduce the risk of virus contamination and spread,” the researchers conclude.
This research is set to be presented at the 2020 European Congress on Clinical Microbiology and Infectious Diseases.