Upon My Sole—How Your Footwear Could Be Opening Your Home to Intruders

What’s THAT on your shoe???

This time last year, a Beverly Hills jeweler claimed to have broken the Guinness World Record for the most expensive shoes in the world.

He’d designed a pair of men’s smoking slippers encrusted with 14,000 diamonds set into white gold.

The price tag? $2 million.

Now, setting aside the fact that this seems an awfully steep price to pay for footwear of any kind—let alone the sort you only wear when smoking—I’m pretty sure you’re not going to wander the streets in two-million-dollar slippers.

I suspect they’d be reserved for indoor use only.

And this is probably a good thing, for more reasons than one.

You see, there’s a lot to be said for thinking hard about what happens when you wear your outdoor shoes indoors.

Back in 2008, a study conducted out of the University of Arizona found extraordinary amounts of bacteria on the bottoms of shoes.

The average sole harbored 421,000 bacterial units, each consisting of enough bacteria to reproduce and grow a new colony.

Admittedly the research was sponsored by a manufacturer of machine-washable shoes (actually a pretty neat idea when you think about it) but the findings make sense.

Project leader Dr Charles Gerba said the study detected nasties like Escherichia coli (E. coli), Klebsiella pneumoniae (which can cause urinary tract infections), and Serratia ficaria (linked with respiratory infections) all lurking on the bottoms of people’s shoes.

This really isn’t surprising, he added, when you consider that shoes come into frequent contact with fecal matter, originating from floors in public restrooms, or contact with animal fecal matter outdoors.

Hardly walking on sunshine, is it?

There’s a lot to be said for religious and cultural traditions in Asian and Scandinavian countries, among others, of leaving one’s shoes at the front door.

And maybe we could all learn from this?

It has to be particularly important in homes where there are children under the age of 2, who are the most vulnerable to floor-borne germs.

Kids play on the floor and at that age put their hands in their mouths dozens of times an hour.

Of course, limited exposure to bacteria may be beneficial, helping to build up immunity.

But when you stop to reflect on what could well be on the soles of your shoes, it may make you think twice before putting a baby down to play, or yourself reaching for that tantalisingly tasty morsel of food you just dropped on the floor.

For the Japanese, not wearing outdoor shoes indoors is a matter of everyday living.

It makes sense, after all, when you’re eating on tatami mats on the floor, and sleeping on futons rolled out at night.

Others of us may need more scientific evidence to persuade us to change our ways.

Another study, this time at the University of Houston in 2014, swabbed the bottoms of shoes to reveal that almost 40% of them tested positive for potentially pathogenic C. difficile.

In the same year, research at the University of Chicago examined public restrooms, finding that between five and eight hours after their floors had been decontaminated, bacteria levels had returned to their pre-cleaning baseline, even when no humans had gone back in.

Cleaning, it seems, generally only reduces the level of bacteria, rather than completely eradicating it.

And bacteria love nothing more than to reproduce.

For some, the “shoes-on/shoes-off” thing can be socially challenging.

For example, there’s often that awkward moment when you arrive at someone’s house for the first time, and are looking around for obvious signs of this being a no-shoes type of place.

Best not get it wrong, though, because some folks get pretty passionate about this whole thing.

Consider for example, a wonderful blog named “Shoes Off At The Door Please” which has amassed over 1,500 posts since coming online ten years ago.

In addition to making many great points about the hygiene benefits of removing shoes at the front door, the blogger also wisely suggests that “psychologically, removing shoes helps you to enter a frame of mind where you keep your everyday troubles outside your home.”

We’ll end, therefore, on an uncharacteristically non-bacterial note, by also drawing attention to educational visionary Professor Stephen Heppell, currently at Bournemouth University in the UK, who says he has observed that many schools which insist that everyone goes shoeless—students and teachers alike—have ended up seeing better behavior, especially less bullying.

“It seems to be more difficult to be a bully with your shoes off,” Professor Heppell says.

And so maybe it’s not only unwanted microbes we can avoid by leaving our shoes at the door.

But also unwanted mindsets.

Further reading

5 Ways To Enforce a “Remove Shoes” Policy In Your Household

7 Reasons Why You Should Consider Adopting a No-Shoes Policy in Your Home

Ecological succession and viability of human-associated microbiota on restroom surfaces

Germ Tracker – Study Reveals High Bacteria Levels on Footwear

Investigation of potentially pathogenic Clostridium difficile contamination in household environs

Shoes Off at the Door, Please

The disgusting bacteria your shoes are bringing into your home

The secret to calm classrooms – Lose the shoes

What Your Shoes Bring Home

World’s Most Expensive Shoes Break Guinness World Record