Paper towels are far more effective in eliminating viruses from hands than jet dryers, according to new research from the University of Leeds.
Hand drying is critical for minimizing the spread of dangerous microbes, including the virus that causes COVID-19. Viruses that are not removed from the hands during the drying process are easily transferred to surfaces, where they are picked up by others.
“We believe that our results are relevant to the control of the novel coronavirus that is spreading at pace worldwide,” wrote the study authors. “Paper towels should be the preferred way to dry hands after washing and so reduce the risk of virus contamination and spread.”
To investigate the effectiveness of each hand drying method, the researchers analyzed the extent of virus transmission beyond a public restroom in a hospital.
The hands of the study participants were contaminated with a bacteria that is harmless to humans known as a bacteriophage. The individuals did not wash their hands after contamination, and dried them with either a jet air dryer or paper towels.
The volunteers wore aprons so that body and clothing contamination could be measured. After drying their hands, the individuals ventured out into common areas of the hospital. Samples were collected from surfaces that made contact with a participant’s hand or apron.
The sites sampled included doors, stairs, handrails, lift buttons, chairs in public areas, phones, buttons on access intercoms to wards, stethoscope tubing, and armchairs.
The study showed that both hand drying methods reduced virus contamination. However, across 10 out of 11 surfaces, the researchers found substantially greater contamination after jet drying.
The average surface contamination following contact with jet-dried hands was more than 10 times higher than contact with hands dried using paper towels.
The aprons worn by participants contained five times more bacteria after jet drying, and the transfer of germs from the apron to an armchair was only detected after jet drying. This particular finding indicates that a person’s clothing or body can become contaminated after using a hand dryer, and the germs can be transferred to other surfaces.
“There are clear differences, according to hand drying method, in the residual microbial contamination of the subject’s hands and body,” wrote the researchers. “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.”
“As public toilets are used by patients, visitors and staff, the hand drying method chosen has the potential to increase or reduce pathogen transmission in hospital settings.”
The research will be presented at the European Congress on Clinical Microbiology and Infectious Diseases.