Most of us are used to using jet hand dryers (喷射式干手器) in public restrooms. They're surely very convenient- all we need to do is to hold up our hands for a few seconds until they're dry. And more importantly, they're supposed to be hygienic (卫生的).
However, a new study published in the journal Hospital Infection found that jet hand dryers actually spread more dangerous bacteria (细菌) than paper towels.
In the study, two restrooms in each of three different hospitals in the UK, France and Italy were required to provide both jet air dryers and paper towels for people to use. But on certain days, only either the hand dryer or the paper towel dispenser (自动出纸机) was available to use.
The scientists found that when only the hand dryer was available, the amount of bacteria in the restrooms was 27 times higher than on other days.
According to study leader Mark Wilcox, an expert in medical microbiology (微生物学) at Leeds University, UK, air dryers spread harmful bacteria all over the room. This means that if people use these dryers, they're more likely to pick up bacteria.
At the same time, however, this raises the question of why these bacteria exist in the first place if people are washing their hands after using the restroom.
"The problem starts because some people do not wash their hands properly," Wilcox told The Telegraph. In other words, poor hand-washing leads to a large amount of bacteria being left on your hands.