A leading microbiologist has disputed the findings of a recent academic report from the UK claiming that hi-tech jet hand dryers can facilitate the spread of pathogens by blowing them into the air.
The 2014 study led by professor Mark Wilcox from the University of Leeds found that jet hand dryers spread 27 times more bacteria and microbes than paper towels, as well as four times more than standard hand dryers.
According to the study, because of the very nature of the way they work, jet hand dryers facilitate the airborne spread of microbes – a critical channel of pathogen transmission in a bathroom environment given the confined nature of the space and relatively close proximity of occupants.
Dr. Benjamin Tanner, president and CEO of Texas-based Antimicrobial Test Laboratories, disputes the findings of the University of Leeds study on multiple grounds, stating that the health concerns raised are overblown and the study’s testing methodologies defective.
According to Tanner, any of the transient microbial flora that are found in human effluent and pose a health threat are easily removed by ordinary washing, and thus unlikely to be spread jet hand driers if users have already gone to the trouble of scrubbing their hands.
“I disagree with the premise of the Best, et al. study from Leeds University, namely that splashes that result from drying hands with dryers poses health risks,” said Tanner. “Put simply, if the potentially dangerous microorganisms have already been washed away, what is the concern?”
Tanner also took the Leeds team to task for the methodology they employed in they research.
“I take issue with virtually every test method used in the study,” said Tanner. “The authors contrived a model system for testing that is far removed from ‘real life.'”
According to Tanner, the smooth disposable gloves donned by volunteers do not adequately replicate the texture of human skin, to which bacteria and flora can stick much more tightly.
“In real life ordinary flora cling tightly to hands so I would not expect levels of aerosolization anywhere near what was reported by the researchers,” said Tanner. “I am disappointed that Leeds University did not perform a more realistic study. A well done study would have measured levels of disease-causing organisms on the hands, then measured the number of those bacteria that are blown off as a result of drying.”