Hey I’m Elliott. This is Mental Floss on YouTube. Today I’m going to talk about some
misconceptions about cleanliness and germs.
Misconception #1: The Five Second Rule. If you’ve been to elementary school, and
I hope you have, I’m sure you’ve heard this one. Some claim that if you pick food
up off the ground within five seconds of it being dropped, it’s germ-free and safe to
eat. There've actually been scientific studies on this and they’ve found that bacteria
DOES make its way onto food immediately after it hits the ground. It IS a smaller amount
though, so the sooner you pick it up, the less bacteria it will have. And the surface
that it’s dropped on does make a difference. There’s less bacteria transfer from a carpet
than there is from a smooth surface. But the germs aren't like -- 5, 4, 3, 2, 1, 'cause
they can't, they don't have that kind of self control.
Misconception #2: Soap kills germs. Soap is actually a surfactant. So, when you
wash your hands, you combine soap with water, then surface tension decreases. This allows
for the bacteria to be released from your hands, then they just go down the drain. They
go, wahhhh. Like that.
Misconception #3: Viruses stay alive on hard surfaces for a long time.
It’s normal to be a little weirded out about touching things like doorknobs and railings
in public spaces. But, the truth is, viruses and bacteria do die on hard surfaces. How
long they stay alive depends on the specific type. The flu virus typically only survives
between 2-8 hours. The cold virus lasts longer but is unlikely to get you sick after 24 hours.
The herpes virus dies after four hours.
Misconception #4: Urine disinfects burns and stings.
Urine isn’t a disinfectant. See, aren;t you glad you watched this episode? In fact,
a 2014 study conducted by the Loyola University Health System found that there’s actually
bacteria in healthy, human bladders. So, not only is your urine not a disinfectant, it’s
also not that safe-slash-sterile in general.
Speaking of TOILET STUFF… Misconception #5: The toilet seat is very
germy. Well, it’s probably not the cleanest place
on earth, but you’re unlikely to get a disease from it. And it’s definitely a misconception
that you can contract an STD from the toilet seat. According to a 2002 University of Arizona
study, there’s around 49 germs per square inch on the toilet seat. Compare that with
the around 21,000 germs per square inch they found on people’s desks at work. Still,
you shouldn’t touch the toilet seat with your hand. Plus, the flush handle and other
surfaces in the bathroom are even dirtier, so make sure you wash your hands! Why don't
you just wear gloves all the time?
Misconception #6: Everyone washes their hands. According to a 2013 study from Michigan State
University, 10% of people don’t wash their hands after using a public restroom. GROSS.
And that’s here in a developed countries where we have all of the right resources.
Hand washing can reduce the risk of diarrhoeal diseases, which affects 1.7 billion people
around the world each year. A 2003 review of seven hand-washing studies found that if
everyone DID wash their hands, there would be between 0.5 million and 1.1 million less
deaths from diarrhoeal diseases annually. That's INSANE.
Misconception #7: Everyone washes their hands correctly.
According to the same Michigan State University study that I mentioned earlier, 95% of people
aren’t washing their hands long enough to get rid of germs. So, let’s take this into
the bathroom so I can show YOU how to wash your hands.
Ok, so the first thing you're going to need is some clean water. It can be either hot
or cold, I prefer tepid. Just lather your hands like this. Now, once you have your hands
nice and lathered you want to do this for about 20 seconds. The Center for Disease Control
and Prevention says that length is about the same as singing “Happy Birthday” twice,
which obviously I'm not going to do because it’s copyrighted. Actually, by a guy named
Tim Birthday, a lot of people don't know that. And also I'm a horrible singer. And after
you're done just rinse it like this, huh, bet you didn't know that! Turn off the water,
that's important too, and then you dry off your hands -- thank you so much, sir.
Misconception #8: Hand dryers blow germs around. The microbiology department at the University
of Ottawa has conducted studies about this and determined it to be not true. Hand dryers
are NOT blowing germs all over you. Some claim that dust starts to build inside, leading
to bacteria build up, but that has also been debunked. Other studies show that hand dryers
blow bacteria around the room. But these have continually been shown to not be harmful and
no outbreak has ever been associated with hand dryers. Unless you’re washing your
hands in the emergency room of your local hospital, dryers are fine. Also though, the
cool ones are the ones that you put your hands in and it's like the blade, you've seen those?
Oh, they're so cool.
Misconception #9: Dirty people get lice. Unfortunately you can wash your hair every
single day, but that won’t make lice any less attracted to you. All it takes is head-to-head
contact with someone who has lice. And this happens to 6-12 million kids between the ages
of 3-12 years old in the U.S. each year. I think I’m going to start wearing a hairnet
around. And maybe stop hanging around playgrounds. Which I should probably stop doing anyway.
Misconception #10: Hand sanitizers cause bacterial resistance.
Many believe that hand sanitizers create antibiotic-resistant bacteria, also known as superbugs. Superbugs
are real and infect around 2 million people a year, but probably not due to hand sanitizer
use. The alcohol in hand sanitizer kills the majority of bacteria on your hands, which
involves breaking down the protein in the bacteria’s contents. That protein breakdown
makes resistance unlikely. It’s antibiotics that tend to create superbugs. As long as
your sanitizer is at least 60% alcohol and does not contain either triclosan or triclocarban,
then you’re in the clear.
Thank you for watching Misconceptions on Mental Floss on YouTube, which is made with the help
of all of these nice people. If you have a topic for an upcoming Misconceptions episode
that you’d like to see, leave it in comments and we'll check them out. I'll see you next
week!