Washington Post:

Researchers coated subjects’ hands with Lactobacillus, a harmless bacteria that you don’t typically come across in a public bathroom. The idea was to mimic hands that hadn’t been washed properly. After drying hands, researchers went in and conducted 120 air-sampling tests. They found that Lactobacillus counts in the air were 4½ times higher near high-powered jet dryers than around warm-air dryers. And bacteria counts were 27 times higher near warm-air dryers than when subjects used paper towels.

Ok, that’s it. I’m simply not going to use public washrooms any more.