Hand dryers are a staple in public bathrooms and are marketed as an eco-friendly way to dry hands. But the results of a new study may make anyone think twice before using one again.
Researchers at the University of Connecticut School of Medicine found that hand dryers may suck up bacteria from flushing toilets and spread that bacteria to hands.
Bathrooms without hand dryers had just six pathogens compared to the 254 pathogens found in bathrooms with hand dryers.
The bacteria may also be spread to other parts of the building.
According to the study, “Within a large building, potentially pathogenic bacteria including bacterial spores may travel between rooms.”
Peter Setlow, author of the study, told Newsweek, “Bacteria in bathrooms will come from feces, which can be aerosolized a bit when toilets, especially lidless toilets, are flushed.”
Theoretically, adding HEPA filters to the dryers should stop the spread of bacteria. But when the team retrofitted the dryers with these filters, they only blocked about 75% of the bacteria. While impressive, the results weren’t ideal.
Hand dryers in bathrooms do more than just blow air – they also suck it up, according to Sli Mag. When blasting out air, these dryers also suck up air and bacteria that can fester inside of the unit and be redistributed to the next user. The germs can then be spread to other rooms in the building.
The study concludes that hand dryers are a “possible mechanism for spread of infectious bacteria including spores of potential pathogens if present.”
News of the study may be enough to make some businesses reconsider their bathroom design, but it’s important to remember that most bacteria are harmless to humans. In fact, they are essential to life on earth and are one of the earliest forms of life on this planet.
Microbes are an essential part of the human immune system. They interact with and sometimes even control our genes. Some experts recommend exposing children to as much bacteria as possible, as there is some evidence that exposure to a wide array of bacteria helps build a strong immune system.
The results of the study support an earlier viral photo of a bacteria-laden petri dish. Nichole Ward placed a petri dish inside of an enclosed hand dryer in a public bathroom for just three minutes. After a few days, the dish was covered in bacteria.
The photo, posted in a Facebook post, went viral.
A study from 2014, published in The Journal of Hospital Infection, compared the use of paper towels, warm-air dryers and high-powered dryers. Higher amounts of germs were found in both types of air dryers compared to hand towels. High-powered dryers were the worst. Bacteria in the air around them was 4.5-times higher than the air around the warm air dryer and 27 times higher than around paper towel dispensers.
Interestingly, the results from this study and the most recent one contradict another study from 2000, published by the Mayo Clinic. The Mayo Clinic study found no statistically significant difference between paper towels and dryers when it comes to hygiene.