Your cell phone
That thing you're pressing to your face? There's a 16 percent chance it has fecal matter on it, London researchers found. And even if it's not brimming with E. coli, nine in 10 cell phones carry some kind of disease-causing germ, like influenza or MRSA. Think about it: You take your cell phone everywhere—public transit, the bathroom, the office—and you never clean it.
- YOUR FIX: Wipe it with an electronic-safe disinfectant wipe like Wireless Wipes or CleanTouch once a week, says Charles Gerba, Ph.D., a professor of microbiology at the University of Arizona.
You probably cleaned your toilet more recently than you cleaned your grill—and that's not a wise choice, considering the latter comes in contact with your food. The average grill has 1.7 million microbes per square inch, according to a 2013 British study. That's more than twice as many bacteria as the average john. It makes sense that your grill is nasty because food particles cling to the grates and work surfaces.
- YOUR FIX: To give it a deep clean, scrub the grates with soap and a scouring pad, scrape out any charred bits from the bottom, clean out the gook in the burners with a paperclip, and rub down the entire exterior with an ammonia-based cleaner and a paper towel.
Your 'clean' laundry
Crap clings to your underwear, whether you can see it or not. When you throw your undies in the laundry, you transfer about 500 million E. coli bacteria to the machine, according to Gerba. On top of that, water tends to settle in the bottom of front-loading machines, making it a breeding ground for germs. Then you wash your clothes in that mess.
- YOUR FIX: To make sure your clothes come out actually clean, do a load of whites first so you can use chlorine bleach to sanitize the machine. Dedicate a cycle to underwear and use hot water with a color-safe bleach substitute. Also, run an empty cycle with bleach once every month to keep your washer free of bacteria.
When you flush your toilet, it can spray aerosolized droplets over 20 feet, says Philip Tierno Jr., Ph.D., director of microbiology and immunology at NYU's Langone Medical Center and the author of The Secret Life of Germs. So if you leave your toothbrush out on the bathroom sink, it could be showered with tiny drops of whatever you just flushed.
- YOUR FIX: Stowing your toothbrush in a cabinet away from the flying feces might be a good idea. Running it through the dishwasher will also eliminate germs, according to a 2011 study in the American Journal of Dentistry. An even easier option: soak your toothbrush in a mouthwash that contains cetylpyridinium chloride, like Scope, for 20 minutes.
Your kitchen sponge
Your sponge is probably the nastiest thing in your kitchen. It's damp and constantly in contact with bacteria, making it a prime place for germs to proliferate. There's a one in three chance your kitchen sponge has staph, according to a Simmons College study. (That's twice the contamination rate of your toilet.) And it could be harboring 10 million bacteria per square inch—that's 200,000 times dirtier than your toilet, according to studies from the University of Arizona.
- YOUR FIX: To kill germs, nuke your wet sponge in the microwave for 1 minute. It’s that simple.