Sponges are notorious for soaking up bacteria and other bugs. As it turns out, kitchen towels can be just as germy.

When University of Arizona researchers analyzed kitchen towels collected from homes in five major cities in the United States and Canada, they discovered that nearly 90 percent of the towels were teeming with enteric organisms — bugs from the intestines and feces of humans and animals. (Yuck.)

About a quarter of the kitchen towels contained E. coli, gut bacteria that can be benign but may also cause serious illness and even death. (Bacteria such as E. coli are found primarily in raw meats but can also show up in produce.) The researchers also found salmonella in 12 percent of the samples.

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It’s likely the towels soaked up the germs when they were used to clean up kitchen counter spills, says Kelly Reynolds, PhD, who helped conduct the research. “The problem with kitchen towels and sponges is they provide a moist environment and, if they contain food particles, nourishment for bacteria to grow,” she explains. “E. coli doubles in population size every 20 minutes, so it doesn’t take long to have millions more than what you started with.”

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Synthetic microfiber towels, which pick up even the tiniest specks because of their static charge, might be worse than cotton for harboring bugs. “Bacteria and viruses have a static charge, so they tend to stick to these cloths,” adds Reynolds.

Conquering kitchen towel contamination

Here are five tips for preventing kitchen towels from doubling as germ hotels:

1. Throw in the towel every night. “Buy a bunch of inexpensive white hand towels for your kitchen,” suggests Reynolds, “and toss used ones into the laundry each night.”

2. Wash kitchen towels separate from clothes. “You don’t want to contaminate your underwear with dirty kitchen towels,” says Elizabeth Scott, PhD, co-director of the Center for Hygiene and Health at Simmons College of Arts and Sciences in Boston.

3. Use your washer’s sanitizing cycle. Many modern washers have a special setting for sanitizing. Some even use silver in the rinse cycle. (Silver is an antimicrobial agent found in everything from cleaning cloths to hospital gowns.) If your washer doesn’t have that option, wash towels in hot water and, if they’re plain white, add bleach.

4. Use a bleach soak for “instant” results. After using a kitchen towel, drop it in a sink filled with water (dishwater is fine) to which you’ve added bleach. (Different bleach brands have different concentrations of sodium hyperchloride, so check the bottle for instructions on the correct ratio of water to bleach.) A 30-second dip will get rid of most of germs. Soaking for four to 10 minutes will completely disinfect a dish towel, says Reynolds. Then you can let it dry out and use it to wipe down counters.

5. Keep your hands clean. "Using a germy kitchen towel to dry your hands is a recipe for spreading illness,” says Reynolds. Reach for a paper towel instead after washing your hands in the kitchen. 

Denise Foley is a veteran health writer and a former contributing executive editor at Prevention magazine.