person using hand dryer
Julie Hambleton
Julie Hambleton
February 5, 2024 Â·  4 min read

Hand Dryers Spread Bacteria So Dramatically That Scientists Think They’re A Public Health Threat

In the past few years, one thing was made abundantly clear across the world: Proper handwashing is really, really, important for public health. One important, and perhaps overlooked step in proper hand washing is the last one, the drying step. There are various methods for hand drying, however, some scientists warn that the automatic hand dryers in public bathrooms actually do more harm than good.

Hand Dryers Are A Public Health Nightmare

Drying your hands after washing them is an important step in preventing the spread of bacteria. This is because when your hands are wet, you are more likely to leave bacteria on other surfaces than if they are dry. Wet hands act as a humectant, meaning that the moisture allows bacteria to stick to surfaces more easily. Most public bathrooms offer either paper towels or some kind of automatic hand dryer to dry your hands with. Unfortunately, those super-speed hand dryers that have become more popular over the years are the worst of them all. They are so bad, in fact, that many hospitals have removed them from all of their bathrooms. (1)

In 2014, a University of Leeds research team discovered that no-touch jet dryers in public bathrooms spread bacteria around the bathroom faster even than they dry your hands. Not only that but those pathogens and bacteria continued to float around in the air for up to 15 minutes after use.

The Hospital Experiment

This information is obviously highly important for places like hospitals, where there are vulnerable people as well as resistant bacteria that can be a huge danger to people’s health. A group of researchers replicated the Leeds experiment but in a real-world situation. They set up their study in two bathrooms in hospitals in three different cities: Leeds, Paris, and Udine, Italy. In each hospital, one bathroom was set up with only paper towels, the other with hand dryers. They took air samples and swabs of various surfaces every day for four weeks. Next, they took a two-week break when they swapped around which bathroom had the paper towels and which had the dryers. They then repeated the sampling and swabbing as before. The process was also repeated a third time.

The researchers found that the number of bacteria in the air and on surfaces was consistently higher in every restroom where hand dryers were used. Though the bacteria was highest in the Udine bathrooms, it was in the UK bathroom where they found several resistant bacteria. 

“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,” the research team wrote.

Read: Woman shocked to discover tiny dots on skin were a sign of something worse.

Why So Much Bacteria?

The issue, lead researcher Mark Wilcox says, is because of the lack of proper hand washing in the first place.

“The problem starts because some people do not wash their hands properly,” Wilcox explained. “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.”

The slow-drying, warm air dryers don’t necessarily blast the bacteria around like the jet-dry versions, but they aren’t much better. Paper towel is also not perfect, but bacterial speaking they are much better.

There are other reasons, as well, as to why there is a lot of bacteria in the air in a public bathroom. For example, flushing without putting the lid down releases a fine mist of microbes into the air. These stay in the air for a time and can disperse over an area as large as six square meters. (2)

Bathroom Best Practices

There are a few things you can do to reduce your risk of exposure to bathroom bacteria and reduce bacteria spread. First, if it is an option, close the toilet lid before flushing. Second, wear a mask, particularly in areas with vulnerable people and if you have a respiratory infection. If you’re coughing or clearing your throat, do so into a paper towel and discard that towel immediately. Wash your hands fully and properly with soap and water. When you’re done, dry them thoroughly, preferably with a paper towel. (3)

Keep Reading: Scientists Amazed At Health Of Man, 87, Who Has Not Washed For 65 Years And Eats Raw Roadkill

Sources

  1. Jet-air dryers should not be used in hospital toilets.” Leeds.  September 7, 2018.
  2. The bacterial horror of hot-air hand dryers.” Harvard. John Ross, MD, FIDSA,. May 11, 2018.
  3. We know hand dryers can circulate germs through the air. Why are they still used everywhere?The Conversation. Christian Moro and Charlotte Phelps. March 29, 2021.