Most people don’t realize that when it comes to spreading germs, the kitchen is a bigger culprit than the bathroom, says microbiologist Philip Tierno of New York University and author of The Secret Life of Germs. The kitchen faucet, refrigerator handle, and microwave buttons are some of the germiest things in your house, mainly because so many people touch them and yet they’re rarely cleaned.
As for the kitchen sponge? “It’s the worst,” says Tierno, because bacteria thrive in the sponge’s damp crevices. A survey last year by the Hygiene Council, an international group of infectious disease experts, found that 70 percent of kitchen sponges and cloths in the United States had high levels of bacteria. When those contaminated sponges are used to wipe down the counters, “you just spread the bacteria around,” notes Chuck Gerba, an expert in environmental microbiology at the University of Arizona.
Colds, stomach flu, even food-borne illnesses can be spread by touching the germy surfaces in our homes. The kitchen, where raw food is prepared, can be host to pathogens like salmonella and E. coli, which can sicken older Americans with weakened immune systems, notes Tierno. “Those who are diabetic or caring for elderly parents should pay attention to the germ hot spots in their homes,” he says.
A 2008 study by the University of Virginia found that the cold virus can live on surfaces around the house for up to two days. Most frequently contaminated were doorknobs, refrigerator door handles, TV remote controls, and bathroom faucets—all items that had been touched by study participants suffering from the common cold.
Other viruses, says Gerba, can survive on household surfaces from a few hours to several weeks. The norovirus, which causes diarrhea, can last for several weeks.
So what’s the best way to disinfect the items and surfaces we touch the most?
Nuke the sponge. “Put the sponge in about an inch of water in a container and microwave it for a minute,” says Tierno. The water helps conduct the heat evenly so it can kill any bacteria or viruses. You should do this daily, especially if you’ve used the sponge to clean up after food preparation. Don’t put your sponge in the dishwasher unless you have a special high-heat germicidal cycle, warns Tierno. The regular dishwasher cycle isn’t hot enough to disinfect a germy sponge.
Use bleach diluted in water. About three tablespoons of bleach in a half-quart or even a quart of water is the simplest, cheapest, most effective way to kill both bacteria and viruses on household surfaces in both the kitchen and the bathroom. “And it won’t stink up your house with fumes,” adds Tierno. There’s also no bacterial resistance to bleach, says Gerba. “Bleach has been used for more than 100 years without a problem.” If making your own solution is inconvenient, you can purchase disinfecting wipes made with bleach. Use them to wipe down light switches, faucet handles, doorknobs, the microwave touchpad, and the telephone.
Don’t forget the drain. Tierno calls the kitchen sink “a repository for germs, especially the drain.” Scrub the drain with a brush and a solution of bleach and water.
Wash your hands. You’ll spread fewer germs around the house if your hands are clean. Use warm water and soap and wash for 15 to 20 seconds—about the time it takes to sing the “Happy Birthday” song twice, according to the Centers for Disease Control and Prevention.
Candy Sagon is a writer with the AARP Bulletin.