Is it really OK to eat food after it falls on the floor?

When you drop a piece of food on the floor, is it really OK to eat if you pick up within five seconds? This urban food myth contends that if food spends just a few seconds on the floor, dirt and germs won’t have much of a chance to contaminate it. Research in my lab has focused on how food and food contact surfaces become contaminated, and we’ve done some work on this particular piece of wisdom.

While the “five-second rule” might not seem like the most pressing issue for food scientists to get to the bottom . . .