The dirty truth about taking your shoes off at the door

At-home holiday parties are on many people's calendars right now, and germ-conscious hosts are faced with a dilemma: Should I require my guests to take off their shoes at the door, especially if the gathering is cocktail or formal attire - or the guest is a stylish shoeaholic like Carrie Bradshaw?

In a 2003 "Sex and the City" episode, Carrie (Sarah Jessica Parker) is asked to leave her $485 Manolo Blahnik shoes at the door during a New York City baby shower hosted by her friend Kyra (Tatum O'Neal) and soon finds they have been stolen.

"I hadn't even done a full lap around the party," Carrie lamented later at a lunch with her friends. The iconic TV character had been forced to walk home in her party dress and old gray sneakers lent by her host.

"Why in the h*ll did you take off your shoes to begin with?" asked Carrie's friend Samantha Jones (Kim Cattrall).

"We had to!" Carrie explained. "For their kids - apparently we drag things in on our heels that make children sick."

While the episode, "A Woman's Right to Shoes," was designed to discuss dilemmas facing single people in a world focused on families with children, the underlying question - and debate - around footwear and health remains: Is there significant evidence going shoeless stops the spread of germs in a home?

"Absolutely," said Gabriel Filippelli, chancellor's professor for the department of Earth sciences at Indiana University-Purdue University Indianapolis and executive director of Indiana University's Environmental Resilience Institute.

"We can track in all sorts of bacteria, but certainly some of the ones we're most concerned about are E. coli that cause severe abdominal cramps, bloody diarrhea and vomiting," he said. "There's been studies that swab the bottom of shoes and something like 99% of the shoes test positive for fecal material."

Heavy metals and more

However, bacteria are not the only danger that rides along with the dust and dirt surrounding rural and urban homes, gardens and parks, said Jill Litt, a professor of environmental studies at the University of Colorado in Boulder who is currently working as a senior researcher at the Barcelona Institute for Global Health, or ISGlobal, in Spain.

"Studies have shown that in urban areas where there are older homes, lead in dust can be tracked into the home on the surface of shoes," she said. "Other studies have shown that you can bring in pesticide residues from gardens via shoes."

Heavy metals like lead and copper and zinc permeate the soils of urban parks and streets from decades of pollutants, while pesticide levels can be high in rural agricultural areas, Litt added.

Homes built before 1978 are very likely to contain lead-based paint, which can chip, peel and disintegrate into dangerous dust, experts say. There is no safe level of lead at any age, but children are especially vulnerable to the toxic effects of heavy metals and pesticides due to their small size and proximity to contaminants as they crawl, roll and play on the floors of the home.

"For little ones, hand to mouth is one of the primary ways children get exposed to toxic substances and infectious disease agents," said Litt, who is also a leader of Reimagining Environments for Connection and Engagement: Testing Actions for Social Prescribing in Natural Spaces. Funded by the European Union, the project aims to fight loneliness with natural spaces.

Wet mop first

Before you ask folks to take off their shoes, be sure the home is as dust-free as possible, experts say. Never vacuum or sweep with a broom first, as that will only stir up all the toxins, sending them airborne. Instead, reach for the wet or spray mop. As counterintuitive as it may be to add water to dirt, it's actually the best way to remove toxins, Litt said.

The same goes for any horizontal surface, Filippelli said, but stay away from feather dusters. "Do more regular cleaning of horizontal surfaces with a damp cloth - that's windowsills, tables, coffee tables, chair bottoms, chair seats and other furniture in addition to the floor."

Use the "three-bucket" method if you live in an older home with lead paint or an area with high levels of lead outside. Have one bucket ready with an all-purpose cleaning solution, another to rinse and an empty bucket.

"Some folks also use a very weak vinegar solution in their wash water, which works really well," Filippelli said. "There are some super sterilizers on the market, but when cleaners are really good at killing bacteria, they're usually not very good for us as human beings. Whenever you can smell a superstrong smell from something, you got to at least think twice about it."

Dip your mop into the cleaning solution, squeeze the excess water into the empty bucket, and begin to mop, starting from the farthest point from the door. Work toward the door, using the clean water as a rinse as you go. Flush water into the toilet when it looks dirty or with each new room - don't throw it outside.

"The highest concentration of germs is in the interior entry way and levels go down as you move greater distances from this area," Litt said. "Carpeting retains a lot of dust so that would be one thing I would remove if you had concerns about dusts and potential health concerns."

Carpeted areas should be vacuumed with a device that has a high-efficiency particulate air, or HEPA, filter, not bagless vacuums, and throw the bag or filter away in an outside trash can when done.

Honor cold feet

Taking off shoes at the door may be the best way to limit germs and potentially toxic dust from coming inside, but that doesn't mean you shouldn't think of your guests' comfort, Filippelli said. Providing washable slippers or nonslip socks can be a thoughtful gesture.

"I do not like to walk around with bare feet inside, so here's my hack. I have some warm slippers right inside my front door - a lot of other cultures do that as well," he said.

"Go to any Asian household, or even a Middle Eastern one and there's often a little cubby right inside the door with washable slippers. You're supposed to take your shoes off there and take the slippers and put those on."

Would that have solved Carrie's shoe-removal problems? No, those were taken care of when she asked Kyra to buy new Manolo's as a gift for Carrie's impending marriage - to herself.

"That's all she registered for?" Kyra asked the salesperson, as her kids ran around the swanky Manolo Blahnik store on Madison Avenue.