Hand dryers in public places are a source of spreading bacteria.
A team of researchers from the University of Leeds has caused a stir by claiming that hand dryers in public toilets are spreading bacteria from people who don't wash their hands properly into the air in alarming amounts.
In lab-based experiments that recreated public restrooms, hand dryers released 27 times more bacteria into the air than old-fashioned paper towels, and those bacteria were still “traveling” 15 minutes later.
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Professor Mark Wilcox and his colleagues set out to examine how hand drying methods affected the spread of bacteria in hospital bathrooms, an important issue because this is where many serious and antibiotic-resistant infections are common.
The investigation was carried out at hospitals in three cities: Leeds, Paris and Udine over a 12-week period. For each location, two bathrooms used by patients, staff and visitors were selected and each was set up to provide only one hand dryer or paper towel.
Air samples and surface swabs were taken daily for 4 weeks, followed by a 2-week pause. Each restroom switched to providing an alternative drying method. This process was then repeated a third time.
The researchers found that the total amount of bacteria in the air and on surfaces was significantly higher in all the washrooms where hand dryers were in use. The most significant differences were seen between the surface of the dryer and the surface of the paper towel dispenser: in Udine, the dryer was covered in 100 times more bacteria, in Paris it was 33 times more, and in Leeds it was 22 times more.
In UK toilets, methicillin-resistant Staphylococcus aureus (MRSA) was found three times more frequently during dryer use than during paper towel use. Bacteria resistant to penicillin, cephalosporins and pathogenic enterococci, a group that is difficult to treat, were also found at significantly higher frequencies and numbers.
The problem starts because some people don't wash their hands properly, explains Cameron Wilcox. In fact, dryers create an aerosol that contaminates the bathroom, including the dryer itself and potentially the sink, floor, and other surfaces, depending on the dryer's design and where it's placed.
Meanwhile, paper towels absorb water and bacteria left on hands and, if disposed of properly, are less likely to cause cross-contamination.
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