Turns out, it's perfectly safe to eat snow...
…if it’s less than 12 hours old. Scientists in Hungary put snow from parks and city intersections in sterile containers, and tried to grow bacteria and mold. The result: Fresh snow had hardly any bacteria. But after 2 days, the bacteria count exploded. Because snow collects pollution particles as it falls. And microorganisms grow exponentially as the snow gets older. So don’t eat snow more than 12 hours old.