At my house, we routinely take off our shoes at the front door, and politely request that guests do the same. We even have a basket of colorful slippers from Ikea that we bring out when we're expecting a large crowd. I inherited this practice from my mother, who no doubt was influenced by the Asian community in San Francisco for whom not wearing shoes in the house is standard. And while in the South the habit may not be as prevalent, there's good reason for allergy sufferers to adopt it.

Allergens and pollutants are much more concentrated inside the home than out. This is compounded by the fact that indoor air may pose health hazards that are not found outdoors. For instance, off-gassing from furniture that contains formaldehyde or the chemicals released by air fresheners, in addition to many other offending items, may be polluting indoor air. (A complete guide can be viewed on the Environmental Protection Agency's (EPA) page The Inside Story: A Guide to Indoor Air Quality.)

Winter is an especially important time to consider the factors that may be contributing to indoor air pollution in your home. As you seal your home against cold weather and huddle indoors for longer periods of time, this is the season that indoor air pollution can have the greatest effect.

So what does taking off your shoes at the door have to do with all this? "Source control" is one of three basic strategies described by the EPA to improve indoor air quality. While matters like asbestos or a faulty heater are larger concerns and should be addressed immediately, seemingly small things like taking your shoes off can also make a difference in reducing indoor air pollution.

Shoes track into the house everything that they've encountered outdoors. In addition to plain old dirt, this includes pesticides found in soil, pollen grains, mold spores, pet dander, and more. With all the allergens in your home already and the efforts you make to reduce them, the last thing you need to do is bring more into the house and spread them all over the place. Institute a shoes-off policy and slip on some cozy slippers instead – it's for your health!

Image courtesy of TreeHugger.com.