“That’s more than we find on hands, or on floors,” Dr. Reynolds says. “Shoes are a common vehicle for bringing major contaminants into the home.” Dr. Reynolds points out that all those germs aren’t a problem until you come into contact with the bottom of your shoe directly, or with the floor they’ve just walked across. “Think about the cycle of transmission,” she says. “Do you have kids crawling around, or do you sit on the floor yourself?” If the germs get on your hand, then you touch your eyes, nose, or mouth, you’ve just completed the cycle of transmission and increased your chances of getting sick. (Eww.) Wait, it gets worse. “Contaminants on the floor don’t always just stay there,” Dr. Reynolds says. “Bacteria are like magnets—they stick to dust particles, and if a person or a pet stirs up dust on the floor, the bacteria-infused particles can be resuspended in the air, where you can ingest or inhale them and be exposed.” The icing on this disgusting cake? Bacteria and viruses don’t die quickly. So the germs the plumber tracked through the kitchen last week might very well still be there today. “It depends on the germ and the humidity, but in general we know bacteria can survive for days to weeks, and viruses for weeks to months,” Dr. Reynolds says. “Definitely long enough for you to come into contact with them.” With all this bad news, you might think Dr. Reynolds has a strict no-shoes policy in her own home. Actually, she doesn’t. “To be honest, I don’t ask others to remove shoes,” she says. “Most people don’t want to walk around your house barefoot.” Some visitors might even have physical ailments that make walking around barefoot difficult or painful. (Of course, all this may not apply if you’re part of a culture where removing shoes before entering a home is expected.) Her simple solution for reducing contaminants on her floor and in her air? “As a hostess, I just remember to clean up afterward.” She points out that each flooring surface has pros and cons when it comes to germs. “Carpeting is notoriously bad because it will trap contaminants over time, it’s harder to clean and impossible to disinfect,” she says. “With hard-surface floors, you can disinfect them with diluted bleach or other solutions.” On the other hand, she says, germs are less likely to go airborne on dust particles when they’re trapped in carpeting. “From hard floors, things get resuspended into air easier.” The bottom line, she says, is that you should be vacuuming weekly and cleaning routinely. To cover your bases, look for a cleaner that has the word “disinfectant” on the label—it is certified to kill both viruses and bacteria, says Dr. Reynolds. Sanitizers, on the other hand, are certified to kill only bacteria (but may kill some viruses). “The labeling is very clear,” she says. “That industry has done good job of making things clear for consumers.” And even if you don’t ask guests to leave their shoes at the door, she suggests household members get into the habit of doing so. “Take them off at the front door, then carry them to your closet shoe rack or basket,” she advises. “Don’t track the germs through the entire house.” Seems like the perfect excuse to buy a cute new pair of slippers.
