In fact, one study found that nearly 96 percent of shoe soles had traces of coliform, which includes fecal bacteria. "The area near your front door is one of the dirtiest in the house," says Reynolds. Once bacteria plant their stakes in your mat, anytime you walk on it, you give them a free ride into your home.
Keep It Clean: Spray the doormat once a week with a fabric-safe disinfectant (such as Lysol Disinfectant Spray). Leave shoes at the door, and avoid resting bags and groceries on the mat, too
It's all in the bag -- including spreadable germs.
"Vacuums -- including the brushes and bags -- are like meals-on-wheels for bacteria," says Charles Gerba, PhD, professor of environmental biology at the University of Arizona. "You suck in all this bacteria and food, creating an atmosphere for growth." A recent study by Gerba and his team found that 13 percent of all vacuum cleaner brushes tested positive for E. coli, which means you could spread it around the house each time you use the appliance.
Keep It Clean: Change your vacuum bag frequently, and do so outdoors to avoid the cloud of bacteria that filters into the air. (Vacuum bags that feature antibacterial linings are best, and are available for many major brands.) Clean the cavity of a bagless vacuum with diluted bleach and let it air-dry.
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You know a sponge can harbor nasty germs, but dish towels are just as dangerous.
A recent study of hundreds of homes across the United States found that about 7 percent of kitchen towels were contaminated with MRSA (methicillin-resistant Staphylococcus aureus), the difficult-to-treat staph bacteria that can cause life-threatening skin infections. Dish towels also rated tops for dangerous strains of E. coli and other bacteria. We often use towels to wipe up spills, says Reynolds, then reuse before washing them, which spreads germs.
Keep It Clean: Stick to paper towels to clean countertops, and save the dishrag to dry just-washed pots and plates. Change towels or launder at least twice a week in hot water and bleach.
This is your vehicle's second-most-common spot for bacteria and mold.
Here's why: When air -- which carries mold spores and bacteria -- gets sucked in through the vents, it's often drawn to the dashboard, where it can deposit the spores and germs. Because the dashboard receives the most sun and tends to stay warm, it's prime for growth. (The number one germ zone? Food spills.)
Keep It Clean:Regularly swipe the inside of your car with disinfecting wipes. Be more vigilant during allergy season -- about 20 million Americans are affected by asthma, which is caused in part by an allergic reaction to mold.
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About 25 percent of public restroom dispensers are contaminated by fecal bacteria.
Soap that harbors bacteria may sound ironic, but that's exactly what a recent study found. "Most of these containers are never cleaned, so bacteria grows as the soap scum builds up," says Gerba. "And the bottoms are touched by dirty hands, so there's a continuous culture going on feeding millions of bacteria."