Generally, we’re not afraid of germs.
However, when we’re out in public, we can’t help but notice people with disgusting habits—habits that could easily make them (and other people!) sick, given the right set of circumstances.
Habits are hard to break, but some clearly warrant making the effort to quit. We’re talking about stuff like..
1. Trimming Your Nails
You’re waiting for your train stop, and you’ve got a few spare seconds. You pull out some clippers and try to discreetly trim your fingernails. What’s the harm?
Well, our fingernails are pretty disgusting. The nail’s basically holding in hordes of germs. One 1988 study described the space right under the fingernails as an “important site” for harboring bacteria, so if you’re cutting far enough, you might actually be releasing infectious agents in the world.
Oh, and your clippings are going everywhere. Nobody wants to get hit by flying bits of disease-ridden keratin.
While we’re at it, don’t bite your nails, either. That’s basically injecting your mouth with a big dose of bacteria.
2. Painting Your Nails
Okay, well, you won’t trim your nails; you’ll just paint them.
Obviously, that’s more obnoxious to the people around you. Nail polish fumes probably aren’t great for the human body; the New York Times reports that “of the 20 common nail product ingredients listed as causing health problems in the appendix of a safety brochure put out by the Environmental Protection Agency, 17 are hazardous to the respiratory tract, according to the agency.”
The same report notes that overexposure can cause “burning throat or lungs,” along with “labored breathing.” Granted, that’s mainly an issue for health care workers, but even limited exposure to nail polish fumes can be dangerous for people with respiratory conditions.
Some of the chemicals in nail polish can also leach into your body, according to HuffPost, so that’s another reason to avoid certain polishes. A 2015 study found that one of the chemicals commonly found in nail polishes can affect hormones in zebra fish—so if you’re a zebra fish, you definitely want to avoid nail polish.
3. Eating While You’re at Your Desk
Here’s the main issue with eating at your desk: You’ll probably touch your keyboard in between bites. Your keyboard is pretty disgusting.
One study found that computer keyboards contained more bacteria than an average toilet seat. Although we’re not sure how the researchers chose an “average” toilet seat, the results were pretty alarming. Toilets contained about 5,400 bacteria per swab, whereas keyboards contained around 7,500 per swab.
And some of the bacteria on the keyboards were of species commonly found in the human digestive tract, including E. coli. Go ahead and ponder that for a minute before taking the next bite of your sandwich.
Of course, you can clean your keyboard by lightly swabbing it with isopropyl alcohol, and you can use compressed air to clean between the keys. Let’s be honest, though, you’re not going to do any of that. Instead, don’t eat in front of your computer—unless you’re pairing your meal with a nice course of antibiotics.
4. Making, Ahem, “Adjustments”
You think that nobody’s watching, so you quickly adjust your underwear. Hey, it needed to be done.
That’s fine, provided that you didn’t make a big deal of it—but make sure you wash your hands. Your underwear are relatively filthy, since they’re in frequent contact with sweatier parts of your body, and that sweat tends to feed bacteria on your epidermis. Hey, science can be disgusting sometimes.
Of course, your outerwear might also harbor bacteria. One study found that typical laundry temperatures aren’t sufficient to kill E. coli, staphylococcus, and other potentially dangerous bacteria.
“If you wash a load of just underwear, there will be about 100 million E. coli in the wash water, and they can be transmitted to the next load of laundry,” said Charles Gerba, professor of microbiology at the University of Arizona.
Detergents don’t really help, either, but bleach (or very hot water) can help to sanitize your laundry.
5. Brushing Your Hair
Your hair can be home to staph bacteria, although the minute amounts on a typical strand of hair won’t be enough to pose a serious health risk. The more important reason to avoid brushing your hair in public: It’s rude. You’ll end up showering nearby strangers with loose hair and dandruff, and even if you think that your hair is gorgeous, it’s not so alluring to strangers who are sitting behind you on the subway.
Guys, you’re guilty of this, too; fiddling with your beard is somewhat gross, as beards are covered in bacteria. One study from a local news station showed that some beards contain more bacteria than the average toilet, although again, we’re confused as to where this “average” toilet concept came from. In any case, fiddling with your beard is bad form, especially if you’re in a conversation with someone.
But even though loose hair can be disgusting, it’s worth noting that many of us eat a bit every day. Some food manufacturers boil hair in hydrochloric acid in order to extract L-cysteine, a common food additive used in bread-making.
6. Putting Your Purse or Bag on the Dinner Table
You arrive for a lunch date and put your purse on the table. That’s a major faux pas, since your purse (or handbag) probably rested on the ground several times on the way to the restaurant.
In a study helpfully titled “A study to investigate the importance of purses as fomites,” Susheela D. Biranjia-Hurdoyal and colleagues noted that “Purses hardly get washed and are discarded, mostly, when they are no longer usable.” As the title suggests, the study aimed to determine whether bags act as fomites—carriers of infectious organisms.
Go ahead and guess the results.
“Purses from both men and women are potential vectors for transmission of diseases across the community,” the study writes. “The use of synthetic purses should be discouraged, as they contribute to increased bacterial colonization.”
The study noted that 95.2 percent of purses were “contaminated.” (Shudder.) By the way, the study also notes that men’s purses seem to have higher rates of bacterial growth than women’s purses, so make of that what you will.
7. Sneezing Into Your Hands.
This is an especially common and disgusting habit, and the implications are pretty obvious.
You probably know that your body sneezes to get rid of germs. A typical sneeze travels at 100 miles per hour—fast enough to spread germs through a small space in a fraction of a second. Your sneezes contain relatively high viral and bacterial loads, so they’re potentially dangerous if you’ve been sick. If you’re going to sneeze, you’ve got to cover your mouth with something, or you’ll risk infecting the people around you.
But whatever you do, don’t use your hands. Public health officials recommend against this practice—you’re supposed to sneeze into your arm—but many adults don’t seem to know that.
Former Health and Human Services Secretary Kathleen Sebelius even called out a reporter for sneezing the wrong way in 2009, offering the reporter an Elmo video that taught the proper method. Ouch.
8. Using Hand Sanitizer
Okay, we’ve basically concluded that everything in your life is covered with a fine layer of germs. Better stock up on the hand sanitizer, right?
Nope. Germs are everywhere, which is exactly why you shouldn’t freak out about them. Although there’s some chance that you’ll get E. coli from your keyboard or a staph infection from your beard hair, either scenario is unlikely.
And hand sanitizer certainly isn’t the answer. One recent study from the University of Missouri showed that hand sanitizers may increase absorption of bisphenol A (BPA), a harmful chemical. Several studies have also shown that hand sanitizers can be too effective, killing off the majority of bacteria but leaving super-strong germs free to propagate.
Ultimately, you should avoid the behaviors on this list to be polite to the people around you, but you shouldn’t really worry about the latest viral story (pun intended) about how “everyday objects are as dirty as toilets.” Germs are everywhere—get used to them.