Do you wear shoes at home? These experts say you shouldn’t
You probably clean your shoes if you step into something muddy or disgusting (pick up your dog, please!).
But when you come home, do you always take off your shoes at the door?
Many Australians don’t.
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For many, what you drag in the bottom of your shoes is the last thing you think about when you get home.
We are environmental chemists who have spent ten years researching the indoor environment and the contaminants people are exposed to in their homes.
Leave your shoes outside, scientists say. File. Credit: William Andrew/Getty Images
While our research into the indoor environment through our DustSafe program is far from complete, the science tends towards the latter.
It’s best to let your dirt out.
What contaminants are in your home, and how did they get there?
People spend up to 90 percent of their time indoors, so whether or not they should wear shoes in the house isn’t trivial.
The policy focus is typically on the outdoor environment for soil, air quality, and environmental risks to public health. However, there is growing regulatory interest in the issue of indoor air quality.
The dust in your home doesn’t just include dust and grime from people and pets that shed hair and skin. About a third of that is from the outside, either blown in or kicked in on those offending shoe bottoms.
Some microorganisms on shoes and floors are resistant pathogens, including hospital-associated infectious agents (germs) that are very difficult to treat.
Add to that cancer-causing toxin from asphalt road grime and hormone-disrupting chemicals in the lawn, and you could see the dirt on your shoes in a new light.
A roll call from indoor nasties
Our work involved measuring and assessing exposure to a range of harmful substances found in homes, including:
Antibiotic-resistant genes (genes that make bacteria resistant to antibiotics) disinfecting chemicals in the home environment microplastics the perfluorinated chemicals (also known as PFAS or “forever chemicals” because they tend to stay in the body and not break down) are becoming ubiquitous in an assortment of uses of industrial, household and food packaging products radioactive elements.
A strong focus of our work has been assessing levels of potentially toxic metals (such as arsenic, cadmium, and lead) in homes in 35 countries (including Australia).
These contaminants, especially the dangerous neurotoxin lead, are odorless and colorless. So there is no way of knowing if the dangers of lead exposure are only in your soil or your water pipes or if they are also on your living room floor.
Science suggests a strong connection between the lead in your home and your garden soil.
The most likely reason for this dressing is dirt blown from your yard or stepped onto your shoes and the furry paws of your adorable pets.
Why have E. coli running around your house when you have a very simple alternative, researchers say? File. Credit: Carol Yepes/Getty Images
This connection ensures that matter from your outside environment stays right there (we’ve got tips here).
A recent Wall Street Journal article claimed that shoes around the house aren’t bad.
The author pointed out that E. coli — dangerous bacteria that develop in the gut of many mammals, including humans — is so prevalent that it’s pretty much everywhere. So it should be no surprise that it can be smudged on shoe bottoms.
But let’s be clear. While it’s nice to be scientific and stick with the term E. coli, in simpler terms, this stuff is the bacteria associated with poop.
Whether ours or Fido’s, it can make us very sick if exposed to high levels. And let’s face it – it’s just downright nasty.
Why walk around your house when you have a simple alternative – take off your shoes by the door?
On balance, shoeless wins
Are there any disadvantages to a shoeless household?
Other than the occasional stubby toe, there aren’t many downsides to having a shoe-free home from an environmental health standpoint. Leaving your shoes near the entrance mat will also leave potentially harmful pathogens behind.
We all know prevention is much better than treatment, and taking off shoes at the door is a simple and simple prevention activity for many of us. Need shoes for foot support? Easy – take some “indoor shoes” never worn outside.
There remains the issue of “sterile home syndrome”, which refers to increased allergies in children. Some claim it is related to overly sterile households.
Indeed, some dirt is probably beneficial, as studies have shown it helps develop your immune system and reduce the risk of allergies. But there are better and less gross ways to do that than walking indoors with dirty shoes. Get outside, bushwalk, and enjoy the great outdoors.
Please don’t bring in the dirtier parts of it to build up and pollute our homes.
Mark Patrick Taylor is the chief environmental scientist at the Environmental Protection Authority of Victoria in Australia and an honorary professor at Macquarie University.
Gabriel Filippelli is Chancellor Professor of Earth Sciences at Indiana University-Purdue University Indianapolis and Executive Director of the Indiana University Environmental Resilience Institute.
This article was first published in The Conversation.