If you feel guilty the next time you pick up the phone to take a sick day, you may be slightly comforted to know that your job might have been the source of your illness.
Whether you work in an office or in a setting where the unclean things around you are more visible, you're likely to encounter plenty of microbes in your workplace.
"One of the reasons things get so dirty and germy is that hygiene hasn't really developed this century for workers," said Charles Gerba, a microbiologist at the University of Arizona, whose work on microbes has earned him the nickname "Dr. Germ."
But while Gerba and other researchers have studied surfaces, it seems no one has ever looked at germs across all occupations.