Mark Patrick Taylor is Chief Environmental Scientist, EPA Victoria, and Honorary Professor, macquarie university. Gabriel Filippelli Professor of Earth Sciences and Executive Director of the Institute for Environmental Resilience at Indiana University, IUPUI.
You probably clean your shoes if you step on something muddy or gross (please pick up your dog’s messes!). But when you come home, you always take off at the door?
Not many people. For many, what you drag on the soles of your shoes is the last thing on your mind when you get home.
We are environmental chemists who have spent a decade examining the indoor environment and the contaminants people are exposed to in their own homes. While our examination of the indoor environment through our DustSafe program is far from complete, when it comes to putting on or taking off shoes at home, the science leans toward the latter.
What contaminants are in your home and how did they get there?
People spend up to 90% of their time indoors, so the question of whether or not to wear shoes indoors is not trivial.
The focus of policy is typically on the external environment for soil, air quality and environmental risks to public health. However, there is growing regulatory interest in the issue of indoor air quality.
Matter that accumulates inside your home includes not just dust and dirt from people and pets shedding hair and fur.
About a third come from outside, blown or stepped on those offending shoe soles.
Some of the microorganisms present in shoes and floors are drug-resistant pathogens, including nosocomial infectious agents (germs) that are very difficult to treat.
Add cancer-causing toxins from asphalt road waste and endocrine-disrupting lawn chemicals, and you might be able to see the dirt on your shoes in a whole new light.
A list of internal evil calls
Our work involved measuring and evaluating exposure to a variety of harmful substances found inside homes, including:
A strong focus of our work involved assessing levels of potentially toxic metals (such as arsenic, cadmium and lead) inside homes in 35 countries.
These contaminants – and most importantly, the dangerous neurotoxin lead – are odorless and colorless. So there’s no way to know whether the dangers of lead exposure are just in your floors or water pipes, or if they’re also on your living room floor.
Science suggests a very strong connection between the lead inside your home and the soil in your backyard.
The most likely reason for this connection is dirt blown in from your yard or stepped on your shoes and the furry paws of your lovely pets.
This connection speaks to the priority of ensuring that the matter of your external environment stays exactly there. (We have tips here.)
A recent Wall Street Journal article argued that home shoes aren’t so bad. The author highlighted that E coli – dangerous bacteria that thrive in the intestines of many mammals, including humans – is so widely distributed that it is virtually everywhere. So it should come as no surprise that it can be rubbed into the soles of shoes (96% of shoe soles, as the article pointed out).
But let’s be clear. While it’s good to be scientific and follow the term E colithis stuff is, simply put, the bacteria associated with poop.
Whether it’s ours or Fido’s, it has the potential to make us very sick if exposed to high levels. And let’s face it – it’s just plain gross.
Why walk him indoors if you have a very simple alternative – take off your shoes at the door?
On the swing, wins without shoes
So are there downsides to having a shoeless home?
Aside from the occasional toe, from an environmental health perspective, there aren’t many downsides to having a shoeless home. Leaving your shoes on the entryway mat also leaves potentially harmful pathogens there as well.
We all know that prevention is much better than treatment and taking your shoes off at the door is a basic and easy prevention activity for many of us.
Do you need shoes to support your feet? Easy – just have a few “indoor shoes” that never wear out outdoors.
There remains the issue of “sterile house syndrome,” which refers to rising rates of allergies among children. Some argue that it is related to excessively barren homes.
In fact, a little dirt is probably beneficial, as studies indicate that it helps build the immune system and reduces the risk of allergies.
But there are better, less gross ways to do this than walking around in your filthy shoes. Get out, go for a walk, enjoy the outdoors.
Just don’t bring the dirtiest parts of it inside to build up and contaminate our homes.
This article is republished from The conversation under a Creative Commons license. read the original article.