[ ♪ Intro ]
It looks like we’ve finally made it through this nasty flu season.
Hopefully, thanks to a flu shot and lots of hand-washing,
you managed to avoid getting sick.
Maybe you even went the extra mile this year and put
on a surgical mask to ward off germs
in crowded, public places.
After all, according to public wisdom, thattotally works, right? Well,
it’s not that simple.
That fetching paper mask might not have actually prevented you
from catching the flu — but
if nothing else, if you were sick,
it probably stopped you from infecting everyone else.
At first glance, those masks might seem really effective —
even according to some research.
In one 2009 study, almost 450 nurses in Ontario, Canada,
were assigned to wear either a simple
surgical mask or an N95 respirator.
These are specially designed masks that mold closely
to the face and block at least 95 %
of tiny particles.
That study, published in JAMA,
found that about 23 % of nurses ended up catching the
flu regardless of the form of protection theyused.
So case closed, right?
Masks must work at least as well as those fancy respirators
at keeping people flu-free.
Except… that’s probably not the case. See,
there ’ s a difference
between getting sick and being exposed to flu virus.
And other studies have shown that surgical masks are definitely worse
at keeping out viruses.
One of those studies,
published in American Journal of Infection Control in 2006, used
samples of a harmless virus to test how
good respirators and surgical masks are at protecting
their wearers from airborne pathogens.
They found that 20 to 85 %
of the simulated pathogens penetrated the surgical masks, compared
to only around 5% for the respirators.
Which is quite the difference.
So even if both groups
of nurses in that first study got sick just as often, the ones wearing
surgical masks were probably exposed to alot more particles.
If you think about it, though, that reallyisn’t that surprising.
Because here ’ s the thing:
Surgical masks aren ’ t actually designed to protect you
from dangerous particles in the environment.
Only respirators are. Instead,
the masks intended for the opposite job —
protecting other people from your germs. See,
while respirators fit tightly to your face,
surgical masks often have gaps on the sides.
They still do a good job covering your mouth and nose,
but outside particles can probably
sneak in around the mask.
So even if they do happen to keep you healthy,
that ’ s not their main purpose. Still,
when it comes to containing your germs,they’re definitely effective.
For a 2013 study published in the journal PLOS Pathogens,
scientists collected examples
of exhaled particles from about 40 flu patients with and without surgical masks.
They found that the masks significantly
reduced the amount of aerosolized virus that their
subjects put into the air.
And a 2009 study
发表于《（美国）临床传染病杂志》 研究发现 医用口罩
from the journal Clinical Infectious Diseases found that surgical masks
were just as effective as fancy respirators at keeping the illness from spreading.
This is why doctor ’ s offices will
ask patients who are coughing or sneezing to put on a mask
while they’re in the waiting room — toprotect everyone else.
According to a Mayo Clinic expert,
if you ’ re not sick yourself, just worried about catching
the flu, wearing a paper mask might help,
and it certainly won ’ t hurt.
But your best bet is still to suck
it up and go get that flu shot.
Thanks for watching this episode of SciShow!
And special thanks to Lorraine on Patreon for asking,
and to all our patrons who voted
to have this question answered!
If you ’ d like to submit a question or vote
on the next ones we answer, you can go to
[ ♪ Outro ]