This is the seriously disgusting reason your air conditioner smells bad

Air conditioners remove mold-friendly moisture from your home and filter allergens before they can get inside. But if you don’t keep them clean, they can make the air in your house extremely stinky, according to a new study out of Hong Kong Baptist University (HKBU).

The study, led by Lai Ka-man, PhD, associate professor in HKBU’s Department of Biology, found that the flakes of skin we naturally shed (scientific name: “skin squames”) get sucked into air conditioning units. Once there, the squames become “lunch” for bacteria living in the units. After the bacteria digest the skin proteins, they produce disgusting smells, including:

  • ammonia, a urine-like odor
  • volatile fatty acids, a B.O.-like smell

RELATED: Your home is covered in germs

18 PHOTOS
18 things in your home that are covered with germs
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18 things in your home that are covered with germs

Sink: It’s where all your kitchen dirt goes (we hope). In fact, it’s home to as many as 500,000 bacteria per square inch. Spray it down often, clean out your food trap, and scrub with scouring powder like Bon Ami at least once a week.

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Cutting boards: Whether you’re chopping meat, veggies or fruit, your cutting board could be Ground Zero for foodborne illness. Prevent cross-contamination by dedicating one board to meats and another to produce. And always wash your board ASAP after using it—especially if you were working with raw meat. Researchers at UC Davis also recommend plastic cutting boards over wood, because they’re easiest to sanitize—they can go in the dishwasher. Clean a wooden cutting board with soap and warm water, dry it quickly, and seal it with butcher-block oil whenever you notice the wood is drying out.

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Countertops: All the action—chopping, mixing, drink-pouring—happens here, so of course they’re covered with little particles of everything. First off, cut the clutter to give crumbs and germs fewer places to hide. Then wipe them with a damp microfiber cloth after every meal.

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Fridge shelves and drawers: Your refrigerator is home to both raw and cooked foods, and if it’s disorganized, they probably come in contact now and then. Store raw meat in a plastic bag to serve as an extra barrier, and stop spoiled food from turning into science experiments by throwing it away as soon as you notice it. Another cool trick we use at our house: Empty and wipe down the shelves and drawers whenever you do a big grocery shop.

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Sponges: They’ve been banned from commercial kitchens—ban them from yours, too. But if you must use a sponge, rinse it with hot water after every swipe. At the end of every day, get it wet and nuke it in the microwave for a minute. Toss it after a few weeks (one week if you’re missing the daily sanitizing routine).

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Dish towels: If you rush through washing your hands, some germs may still be hanging out on them and you’ll transfer those germs to the dish towel. Change dish towels a few times a week, and wash them with hot water when you do the laundry.

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Makeup brushes: They touch your face every day, coming in contact with oils, bacteria and dead skin cells. Wash them with mild soap whenever you notice makeup buildup.

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Towels: Like dish towels, they pick up any germs left after a shower. Plus, if your bathroom has poor air circulation, towels may get musty if they stay damp too long. Wash them in hot water at least once a week.

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Tub: The equivalent of the kitchen sink for your bod, the tub takes in a lot of grime. Wipe it down with a microfiber cloth every day and get rid of mold spots with baking soda or vinegar. (Find dozens more ways to clean with baking soda here.)

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​​​Floor around the toilet: It gets splashed, plain and simple. For starters, make sure to put the lid down every time you flush. Clean up noticeable spots right away and scrub with bathroom cleaner at least once a week.

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Faucet handles: You touch these before your hands are clean. ‘Nuff said. Wipe them down with a damp microfiber cloth.

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Toothbrush holder: It’s all about gravity: Many of the germs on your toothbrush drip into the holder. Rinse it out daily—do double-duty while you’re brushing your teeth with the other hand. Then sanitize your toothbrush holder in the dishwasher (if it can take it) or give it a good scrub with soap and water.

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Electronics: Smartphones, keyboards, mice, the remote control (OK, let’s be real: 17 remote controls)—germy fingers come in contact with them all the time. In fact, the National Institutes of Health recently found that cellphones are 10 times dirtier than toilet seats. Wipe them with a damp microfiber cloth as often as possible. Don’t forget to remove any cases so you can clean underneath.

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Doorknobs, handles and light switches: Even if your hand only touches these items for a fraction of a second, that’s enough time to transfer bacteria. Once again, a quick wipe-down with a damp microfiber cloth will do.

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Shoe rack: Footwear is a huge culprit for bringing germs into your home, so it’s no surprise that their storage unit is a bacterial breeding ground. Put some elbow grease into cleaning this one and wipe it with bathroom cleaner—you never know what somebody stepped in.

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Carpets and rugs: Even if you’re using the no-shoes rule, carpets suck up every crumb, dead skin cell and germ that hits them. Vacuum weekly and spritz high-traffic areas with a carpet sanitizer. If you can toss rugs into the laundry, do it.

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Bags: Your purse holds money (super dirty!) and your kid’s lunch bag holds food (raise your hand if you ever forget to clean it out over the weekend). Follow the manufacturer’s instructions on cleaning these to keep them in the best shape.

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Toys: No matter whose toys they are—your kid’s or the dog’s—they probably spend a lot of time in somebody’s mouth. Consider what they’re made of, then clean accordingly, tossing them in the laundry, dishwasher, or wiping with a cloth.

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“One of the most notable indoor air-quality problems is odor emission,” according to the study, published in the journal, Indoor Air: The International Journal of Indoor Environment and Health. Simply stated, bad smells can have a negative impact on your quality-of-life. In previous research, the authors found that this bacterial process was higher in smelly AC units. The new study is the first to show that skin squames are to blame, although there is a twist: the study also found foul odors in seemingly clean units.

Nonetheless, the authors state that a good filter on your AC could help: “The size of skin squames is generally larger than 10 micrometers (or 0.001 centimeters). A filter that can effectively capture particles less than this size should help improve the odor problem,” Dr. Lai said in a press release. It may also be helpful to get a sealed vacuum with a HEPA filter and use it frequently, suggests Caroline Blazovsky, of My Healthy Home.

RELATED: Get cleaning

13 PHOTOS
Unusual uses for Mr. Clean Magic Eraser
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Unusual uses for Mr. Clean Magic Eraser
1. Remove tarnish from silver
2. Remove the watermark from inside a pool 
3. Clean up spilt nail polish 
4. Clean mirrors 
5. Clean coffee stains and water marks on wood
6. Remove sticker residue from price labels on plastic and glass
7. Remove scuff marks on suede 
8. Remove grease marks, scuff marks on walls 
9. Remove grime from bathroom tiles and marble 
10. Clean sneakers 
11. Remove rust from metal 
12. Clean outdoor furniture 
13. Clean bugs from windshields 
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Here are 15 surprising ways to cut down on indoor air pollution.

The post This Is the Seriously Disgusting Reason Your Air Conditioner Smells Bad appeared first on Reader's Digest.

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