That picture is so hot.
Science
Subscribe to see new publications and popular science coverage of current research on your homepage
I was getting irritated, and ready to criticize all sorts of little details about the imprecision of the article, until the bottom and I realized I was reading an article for kids...
Neato, cool stuff. lol
I just posted it as a trivia, but if you wish to read a more serious and precise lecture, just follow the links provided in the article:
If i recall correctly, there was a centrifuge that spun so fast that the inner contact surface got 100000 PSI of pressure. Some scientists decided to check microbes before and after, and they were still there. Based on that recollection (assuming it is true), the chemicals on your shoe probably do more to microbes than the weight of a "step"