You're exposed to millions of germs and bacteria every day. What's actually harmful—and what's benign but just really gross?

ANNA ROUFOS

Startling reports about germs—from coronavirus to colds to bugs hiding out on your phone case—seem to spread faster than the little buggers themselves these days. Your desk is dirtier than a toilet bowl! Your bathroom is cleaner than your desk! So where to germs grow, and are all of the millions of germs we're exposed to daily actually dangerous?

"Most of the germs we encounter don't come from inanimate objects. Door handles, phones, money, and ATM machines are not a major source of illness," says Elaine Larson, Ph.D., a professor of pharmaceutical and therapeutic research at Columbia University School of Nursing.

Avoiding infection is fairly easy. Basic hygiene (read: washing your hands before eating and after going to the bathroom) gets rid of most bacteria. Those who have to take greater precautions include the elderly and anyone with a suppressed immune system. Plus, you don't want to go overboard with the anti-germ activity: There are lots of "good" bacteria out there that help keep the "bad" germs away.

"The helpful microorganisms overwhelmingly outnumber the harmful ones," says Jack Brown, Ph.D., a professor of molecular biosciences at the University of Kansas at Lawrence. "Removing a large proportion of the good bacteria gives the bad germs a chance to increase and potentially become harmful."

So where do germs grow most and what do you *actually* need to worry about? We investigated the following 12 germy places to find out just how grimy they really are—plus what's true, what's false, and what you really need to do to stay healthy.

Door Handles

Claim: The bathroom-door handle on the public restroom is the germiest place.

False. Door handles actually have the least bacteria of any surface in public restrooms, according to a test by Chuck Gerba, Ph.D., a professor of environmental microbiology at the University of Arizona in Tucson. That's because, according to Gerba's tests, 68 percent of people wash their hands before leaving the restroom. To pick up something like salmonella, which can cause diarrhea, from someone who didn't wash up, you'd need a huge dose of the bacteria, says Larson. Also, most bacteria need a warm, moist environment to survive and can live on hard, dry surfaces for only one to two hours.

Office Objects

Claim: Your office desk is way dirtier than a toilet bowl.

True. The average desktop has 400 times more bacteria than a toilet bowl, simply because people usually don't clean their desks on a regular basis, says Gerba. Most of these germs are harmless, but in a recent study Gerba and his colleagues found the parainfluenza virus, which causes colds and flu, on about one-third of office surfaces. The germiest object: the phone. Viruses such as the flu can survive for two or three days on desktops, phones, and computer keyboards. They're transmitted when you touch contaminated objects and then put your hands on your nose, mouth, and eyes, says Gerba. (By the way, the door handle on the microwave in the office kitchen is also a very germy place. So be sure to wash your hands after heating up your lunch.) Keep microbe levels on your desk down by regularly cleaning with a disinfecting wipe, particularly during flu season. Don't apply disinfectant directly to equipment, which can damage it. Spray first on a paper towel. If you share a phone, clean it every day. Wash your hands often (with warm water and soap or an alcohol-based hand sanitizer), and don't touch your face, says Gerba.

The Floor

Claim: You can get plantar warts and athlete's foot from walking barefoot on the gym floor.

True. Both plantar warts, caused by a virus that produces flat gray or brown bumps on the soles of the feet, and athlete's foot, a fungus that causes flaking and itching between the toes and on the soles of the feet, are often contracted from walking barefoot in the locker room. That's because the floor is warm and damp from the shower and sweat—a perfect breeding ground for viruses and fungi. Always walk around the locker room in flip-flops, and never go barefoot in any public place. (BTW, here’s how to clean up your diet without taking all the joy out of eating.)

Sponges

Claim: Washing a sponge in the dishwasher removes germs.

True. Running sponges in the dishwasher with detergent gets rid of a lot of germs, but putting the sponge in the microwave for a minute will zap even more since it gets much hotter in there, says Brown. Whatever method you use, be sure to do it every other day. Studies by Gerba indicate that sponges are the most contaminated object in the home and can harbor billions of bacteria, including staphylococcus or salmonella, both of which can cause food poisoning-symptoms such as vomiting and diarrhea. It's also wise to rinse sponges well and keep them out of the sink so they can dry out between uses, notes Larson: "Drying kills a lot of germs." You should also change sponges frequently to avoid bacteria buildup; definitely toss them after three weeks.

The Kitchen Sink

Claim: You need to clean the kitchen sink every day with bleach.

False. Kitchen sinks are brimming with germs, but a daily rinse with soap and water prevents bacteria buildup, says Larson. If you've been handling raw meat or poultry, however, be sure to wash your hands, then clean your sink with hot soapy water before you touch anything else or place another food or kitchen tool (knife, strainer) in the sink. Also, every now and then pour some diluted bleach down the drain or garbage disposal. Experts note that bacteria from the sink can spread throughout the kitchen, including faucets and door handles, if you don't wash your hands after you prepare a meal. For example, if you clean raw chicken in the sink, then touch the faucets, or a sponge drops in there before you wash your hands or the sink, you've potentially contaminated the sponge and the faucet.

Your Pillow

Claim: If you've had the same pillow for years, you're bunking with billions of bacteria.

True. But don't lose any sleep over it. The organisms found on pillows are normally harmless bacteria that live on your skin. "You're more likely to become uncomfortable sleeping on a pillow before you reach a point where you're going to get a serious infection from it," says Brown. Plus, pillows themselves aren't breeding grounds for germs: Bacteria need something to live on to multiply, and they can't do that on the materials in pillows (including the stuffing). Worst-case scenario: If you've got a staph infection with a boil, you could reinfect yourself or transfer it, says Brown. "But the chances are low if the pillow has a clean case, which provides a barrier." Wash pillowcases once a week and pillows regularly (most can go in the washing machine). You can change your pillow every five or six years, but experts suggest this for comfort reasons.

Your Bed

Claim: You must wash your sheets every week in hot water or you'll get bedbugs.

False. Washing sheets will get rid of dust mites, microscopic bugs that live on dead skin cells and other allergens. People often confuse dust mites with bedbugs, which are parasites that feed solely on animal blood. They most often hide in mattresses, box springs, and other places near the bed. These bugs won't be eliminated via the spin cycle—unless you can wash in water that has a minimum temperature of 120 degrees. They're spread mainly through luggage (if a hotel room you're staying in has them, for example) and clothing; they can also come into your home on new furniture or spread from a nearby apartment. Only a special professional pesticide treatment plus professional laundering at high temperatures can cure a bedbug problem. Dust mites, on the other hand, are harmful only to those who are allergic to the protein they produce. Otherwise, they're helpful, because they actually remove the dead skin cells that you continuously shed.

Your Toothbrush

Claim: Every time you flush the toilet, your toothbrush gets sprayed with bacteria.

Gross but true. Microorganisms are ejected when you flush the toilet and land all over the bathroom, even if you close the lid, according to research by Gerba. But you probably won't get sick from this. "When the toothbrush dries, most of the organisms will die anyway," says Gerba. Just keep your toothbrush as far away from the toilet as possible, or put it in the medicine cabinet, he says. If someone in the house is ill and using the same bathroom as you are, her germs could be spread this way.

Bathroom Surfaces

Claim: Wash your shower curtain, tiles, and tub once a week to prevent an overgrowth of bacteria.

True. Doing a thorough cleaning once a week prevents the growth of mildew, a fungus that feeds on body oils and soap scum and can cause allergy symptoms including headaches and coughing. Use Clorox Disinfecting Wipes or a mild abrasive such as Soft Soap for tough stains. If mildew does grow on your tub or shower (it forms a thin, often odorous white or black film), you'll need to use a product with bleach to get rid of it. And don't forget to wipe the faucet and spray the shower curtain with some bleach, as both can also harbor germs.

Your Laundry

Claim: Letting wet clothes sit in the washer allows mildew to form.

True. Where do germs grow? Yep, your clean clothes...but they'd usually have to sit for 24 hours, says Larson. Apart from smelly clothing, this could trigger an allergy or asthma attack. If your clothes have a funky odor, you'll have to run the washing machine again. If they still smell, you may have mildew spores, which can multiply into fungus (mildew) growth in your machine. To clean it out, run an empty cycle with hot water and diluted bleach once a month, and always leave the lid open between loads to let the tub dry out completely. You can also end with a bleach load to clean the machine. (Discover 11 ways to make your sweaty clothes stink less.) Laundry is a significant source of organisms, says Gerba, who swabbed 100 washing machines and found that 44 percent of them contained fecal bacteria. Drying will kill e. coli, but salmonella and viruses can remain. The risk of getting sick is small if you're healthy, but if someone in your home is ill, you may want to wash their clothes separately and then do a bleach cycle. You could transfer a virus by touching the clothes and then rubbing your eyes or nose. It's also a good idea to wash your hands after handling dirty laundry.

Your Makeup

Claim: Your makeup is a breeding ground for bacteria.

True. "Any bacteria on your hands or face contaminates the makeup when they come in contact," says Elizabeth Brooks, a professor of biological sciences at Rowan University in Glassboro, New Jersey. Two possible problems can result: pimples, which are caused by bacteria trapped inside pores; and pinkeye, a bacterial infection caused by staphylococcus. Avoid infection by washing your hands before applying makeup and cleaning your applicators weekly. Toss makeup after two months. For foundation, instead of touching the tube or bottle with your fingers, pour it on your hand or an applicator to apply. Another tip: Wipe brushes with alcohol when you don't have time to wash them. (Learn how to clean your makeup brushes in 3 easy steps.) And never share makeup; you can easily transfer infections this way.

Money

Claim: Money is by far the germiest stuff around.

False. In general, because dollar bills are dry, they don't give bacteria a chance to multiply to levels that would make you sick, says Gerba. Plus, the metal in coins actually acts as an antibacterial agent. You certainly don't have to run to the bathroom and wash up after each transaction—unless you sit down to eat afterward, he says. And you should always wash your hands before eating anyway!

Should You Use  Antibacterial Products?

Not unless someone in the house is sick. A recent study found no difference in infectious disease rates in 228 households that used antibacterial items (hand-washing soaps, cleaners, laundry detergent) versus those that used regular products. Plus, there's a potential drawback: A number of studies have suggested that triclosan, an ingredient used in many antibacterial items, may actually foster resistance to many germs. The researchers concluded they're useful only if someone in your home is ill or has a skin or gastrointestinal ailment. Otherwise, Larson says, alcohol- and bleach-based products work best at killing germs without promoting the growth of dangerous "superbugs."

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