“The first test involved E. coli bacteria, ceramic tiles, and gummy bears. It was a simple timed test to see if the gummy bears had picked up any bacteria at all after five seconds. They had. But was the relatively short time they’d been exposed to the bacteria a mitigating factor? What if they’d been on the floor an hour? A second series of tests picked up were the first left off. This one used slices of bread on surfaces contaminated with salmonella. Five seconds of exposure left the bread with between 150 and 8,000 bacteria. A minute left them with about ten times as much. So overall, there is value in snatching a piece of food off the floor as quickly as possible. Still, a minute is twelve times as long as five second, while the food had only picked up ten times the bacteria. Clearly there was a rush of bacteria the moment the food hit the floor.”

From io9.com.