As much as we try to avoid it, sometimes we have no choice but to use a public restroom. Of course, we all know we need to wash our hands after using the toilet (regardless of location), but it always seems like an especially good idea in a public facility because of germs, bacteria and all the other gross particles that come with sharing toilets with strangers.
But really, it’s not just important to wash your hands — how you dry them also matters. And according to a new study, you may want to skip using the hand dryer because it might be spreading fecal (i.e., poop) bacteria onto your hands and throughout the rest of the building. The results, published this month in the journal Applied and Environmental Microbiology, found that compared with normal bathroom air, the stream that comes out of hand dryers had significantly more fecal bacteria colonies.
“Bacteria in bathrooms will come from feces, which can be aerosolized a bit when toilets, especially lidless toilets, are flushed,” study author Peter Setlow told Newsweek. Add to that the fact that many people are moving in and out of the restroom all day, shedding microbes from their skin in the process, and it makes for a pupu platter of bacteria.
The study also found that these bacteria can travel between rooms and throughout buildings courtesy of the rush of air from bathroom hand dryers. While this is important for any public setting, it is an especially crucial piece of information when it comes to designing hospitals and other medical facilities where there may be patients with compromised immune systems or who are particularly affected by the spread of germs and bacteria.
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There is some good news, though: Retrofitting the hand dryers with HEPA filters reduced the bacteria by 75 percent, but ideally, they would take care of the entire job. Your best bet? Stick to paper towels whenever possible.