(CBS News) A new study has found a dirty little secret about hand dryers found in many public restrooms. Researchers say the machines, which are designed to blow hot air on you, are actually sucking up feces particles and spraying them onto your hands.

The report, published in Applied and Environmental Microbiology, found that air blasted out from the hand drying nozzles contains far more bacteria than normal bathroom air. As many as 60 different bacterial colonies can be blown out of the machines in just one 30-second drying.

“The more air ya move? The more bacteria stick,” the study’s author Peter Setlow told Business Insider. “And there are a lot of bacteria in bathrooms.”

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