Should You Let People Wear Shoes In Your House? We Asked a Pro

You may clean your house like a pro, but keeping it clean when others visit can be challenging. You know that people can track in dirt and germs, but when it comes to asking them to take their shoes off when they visit, you may hesitate. Is it rude to ask?

Regardless of your opinion on wearing shoes inside the house, brace yourself because there's no way to sugarcoat this: The bottoms of our shoes are positively covered with bacteria and viruses. Here's what you need to know about shoes in the house.

Why Guests Do (or Don't) Wear Shoes Inside

People might choose to wear their shoes inside your home for many perfectly sensible reasons. On the other hand, others might find removing shoes completely natural.

Reasons to Keep Shoes On

• A guest might feel uncomfortable uncovering their socks (or bare feet).
• Taking off shoes around others implies a level of intimacy that guests might not feel with their host.
• One is less likely to slip and fall while wearing shoes.
• An elderly or health-compromised person might need shoes to walk.
• A guest is only staying for a short period of time.

Reasons to Remove Shoes

• Wearing shoes inside someone's house is seen as a sign of disrespect in many cultures throughout Asia, Europe, and the Middle East.
• In countries such as Japan, removing shoes is a traditional practice dating back to an era when people sat on mats on the floor. It is very common to find various types of shoe storage at the front entrance of homes.
• Those who remove shoes at the entrance of houses of worship (such as Muslims or Hindus) tend to be more comfortable with the habitual practice of removing shoes.
• People are sensitive to the unsanitary effects of tracking in dirt and germs.

What Contaminants Do Shoes Bring Into Your House?

One University of Arizona study found many harmful bacteria on the inside and outside of shoes. Among the bacteria found was E. coli, which can cause intestinal and urinary tract infections, meningitis, and diarrheal disease. Overall, bacteria were detected on the outside of 96% of the shoes.

"That's more than we find on hands or on floors," says Kelly Reynolds, Ph.D., MSPH, professor, environmental microbiologist, and chair of the department of community, environment, and policy at the University of Arizona. "Shoes are a common vehicle for bringing major contaminants into the home."

And the University of Arizona study didn't just find E. coli on the outside of shoes. It found several other harmful strains of bacteria, including Klebsiella pneumonia, a bacteria that causes pneumonia, and Serratia ficaria, which can cause a large variety of infections.

Are Shoes a Health Hazard?

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 you're like most people, you want to stay one step ahead during cold and flu season. But if the tracked-in germs get on your hand, you touch your eyes, nose, or mouth, you've just completed the transmission cycle and increased your chances of getting sick. (Eww.) However, if you clean your floors regularly (and don't have crawling children), wearing shoes inside—sometimes—may not be a huge health issue for your family.

When Germs Become a Problem

Wearing shoes in the house becomes an issue when you don't clean your floors often. Regarding the health hazard involved, Dr. Reynolds has some bad news. "Contaminants on the floor don't always just stay there," she 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 if you haven't cleaned your floors.

"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."

What to Do About It

With all this information, 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 regarding 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."

How to Minimize Your Risk

The bottom line, she says, is that you should be vacuuming weekly and cleaning routinely. To cover your bases, look for a cleaner with the word "disinfectant" on the label—it is certified to kill both viruses and bacteria, says Dr. Reynolds. Shoe cleaners can not only make your shoes look new again, but they can also keep dirt at bay.

On the other hand, sanitizers are certified to kill only bacteria (but may kill some viruses). "The labeling is very clear," she says. "That industry has done a 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.