Half a million bacteria on your shoes – Ogden Clinic provided source, Standard-Examiner 8/4/2015
OGDEN - How often does someone ask you to take your shoes off before coming inside their home?
While keeping the carpet looking nice is a great reason, taking those shoes off before you step inside the house can also protect your health from potentially harmful bacteria, toxin and dirt.
A study from the University of Arizona found an average of 421,000 bacteria with nine different strains on the outside of shoes, including E. coli, which can cause diarrhea and in rare cases meningitis and Klebsiella pneumoniae, which can cause urinary tract infections.
“As gross as it sounds, one of the main sources of E. coli is feces of humans and animals. It lives in our gastrointestinal tract and is actually a beneficial organism when inside our bodies,” said Lisa Stephens, a family medicine physican assistant at Ogden Clinic. “Outside, it can cause severe illness. E. coli can live for days, even weeks on inanimate objects such as shoes. Every time we walk into a public restroom, we can possibly pick up this bacteria. Same can be said for any bacteria or virus.”
Michael Browne, also a family medicine physician assistant at Ogden Clinic, said bacteria are almost everywhere and are sticky on the outside. All we have to do is step on it and it will stick to our shoes.
“E. coli tends to be mixed with fecal material, which sticks to shoes as well. There are two main sources of E. coli on our shoes: Walking through public restrooms, and walking through animal waste outside,” Browne said. “Public restroom floors are contaminated because flushing the toilet sprays E. coli into the air and onto the floor. Grass becomes contaminated when dogs, cats and birds relieve themselves outside.”
Coal tar and pesticides are another concern.
“Coal tar dust is created when vehicles drive on asphalt sealed with the substance. These small particles can be tracked into our homes by our shoes as well,” Stephens said. “Coal tar dust is a carcinogen, something known to cause cancer. A study in 2013 by Baylor University estimated that ‘the average estimated lifetime dose for someone living adjacent to coal-tar-seal coated pavement was 38 times greater than for someone living adjacent to unsealed asphalt pavement. About one-half of that dose occurs during childhood, that is, zero to six years of age.’ Most likely because at this age, children are not only crawling and playing on the floor but also put everything and anything in their mouths.”
Additionally, pesticides can be present for days on our shoes and children are especially vulnerable. Stephens said we would worry about our children rolling around in the grass at a park that had just been sprayed with chemicals, we shouldn’t have to worry about them rolling around on our own carpet.
“Personally, I follow the package directions when I apply lawn fertilizer or other chemicals, then I wait extra time before I let my children or dog play on the grass,” Browne said. “Direct exposure to these chemicals can irritate the eyes, mucous membranes, or skin. Swallowing the chemicals can cause nausea and vomiting. Store these chemicals where children and pets can’t get to them and you should be fine. If your shoes are coated in these chemicals, wash the shoes before wearing them again.”
And finally, while dirt itself is probably not harmful, it’s a good idea not to track it inside on a regular basis.
“The Arizona study found that simply cleaning shoes with detergent eliminated 90 percent of the bacteria. You can also try using rugs that can be washed,” Stephens said. “Place them along the path with the greatest tread and wash often in hot water. Of course, the easiest way is to just remove your shoes at the door. Our homes should be a safe haven for our family and friends not for other little critters.”
Browne agrees dirt itself isn’t harmful, but rather what’s mixed with it. He recommends vacuuming twice a week to reduce the amount of unwanted chemicals, bacteria and allergens in the carpet. If someone in your house has severe allergies, it’s best to replace carpet with solid flooring.
“Personally, I take my shoes off only if they’re visibly dirty or I know I walked in something nasty. Germs are everywhere, and we need to be exposed to them so that our immune systems build up antibodies to them,” Browne said. “So clean your house, practice good hygiene, but don’t live in constant worry about exposure to bacteria and chemicals.”