The Science Is in – You Should Leave Your Filthy Shoes Outside The House
You probably clean your shoes if you step in something muddy or disgusting (please pick up after your dog!). But when you get home, do you always de-shoe at the door?
Plenty of people don’t. For many, what you drag in on the bottom of your shoes is the last thing on the mind as one gets home.
We are environmental chemists who have spent a decade examining the indoor environment the contaminants people are exposed to in their own homes.
Although our examination of the indoor environment, via our DustSafe program, is far from complete, on the question of whether to shoe or de-shoe in the home, the science leans toward the latter.
It is best to leave your filth outside the door.
What contaminants are in your home, how did they get there?
People spend up to 90 percent of their time indoors, so the question of whether or not to wear shoes in the house is not a trivial one.
The policy focus is typically on the outdoor environment for soil, air quality environmental public health risks. However, there is growing regulatory interest in the question of indoor air quality.
The matter building up inside your home includes not just dust dirt from people pets shedding hair skin.
About a third of it is from outside, either blown in or tramped in on those offensive shoe bottoms.
Some of the microorganisms present on shoes floors are drug-resistant pathogens, including hospital-associated infectious agents (germs) that are very difficult to treat.
Add in cancer-causing toxins from asphalt road residue endocrine-disrupting lawn chemicals, you might view the filth on your shoes in a new light.
A roll-call of indoor nasties
Our work has involved the measurement assessment of exposure to a range of harmful substances found inside homes including:
A strong focus of our work has involved assessing levels of potentially toxic metals (such as arsenic, cadmium lead) inside homes across 35 nations (including Australia).
These contaminants – most importantly the dangerous neurotoxin lead – are odorless colorless. So there is no way of knowing whether the dangers of lead exposure are only in your soils or your water pipes, or if they are also on your living room floor.
The science suggests a very strong connection between the lead inside your home that in your yard soil.
The most likely reason for this connection is dirt blown in from your yard or trodden in on your shoes, on the furry paws of your adorable pets.
This connection speaks to the priority of making sure matter from your outdoor environment stays exactly there (we have tips here).
A recent Wall Street Journal article argued shoes in the home aren’t so bad. The author made the point that E. coli – dangerous bacteria that develop in the intestines of many mammals, including humans – is so widely distributed that it’s pretty much everywhere.
So it should be no surprise it can be swabbed on shoe bottoms (96 percent of shoe bottoms, as the article pointed out).
But let’s be clear. Although it’s nice to be scientific stick with the term E. coli, this stuff is, put more simply, the bacteria associated with poo.
Whether it is ours or Fido’s, it has the potential to make us very sick if we are exposed at high levels. And let’s face it – it is just plain gross.
Why walk it around inside your house if you have a very simple alternative – to take your shoes off at the door?
On balance, shoeless wins
So are there disadvantages to having a shoe-free household?
Beyond the occasional stubbed toe, from an environmental health standpoint there aren’t many downsides to having a shoe-free house. Leaving your shoes at the entry mat also leaves potentially harmful pathogens there as well.
We all know prevention is far better than treatment taking shoes off at the door is a basic easy prevention activity for many of us.
Need shoes for foot support? Easy – just have some “indoor shoes” that never get worn outside.
There remains the issue of the “sterile house syndrome,” which refers to increased rates of allergies among children. Some argue it’s related to overly sterile households.
Indeed, some dirt is probably beneficial as studies have indicated it helps develop your immune system reduce allergy risk.
But there are better less gross ways to do that than walking around inside with your filthy shoes on. Get outside, go for a bushwalk, enjoy the great outdoors.
Just don’t bring the muckier parts of it inside to build up contaminate our homes.
Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, Macquarie University Gabriel Filippelli, Chancellor’s Professor of Earth Sciences Executive Director, Indiana University Environmental Resilience Institute, IUPUI.
This article is republished from The Conversation under a Creative Commons license. Read the original article.