This is something I’ve heard a lot, and assuming it’s true, what’s the science behind it? Surely holes in masks are the same size no matter whether the germs are heading in or out, but I’m guessing it’s not about the holes and I’m missing something.
Obligatory disclaimer: I’m not an anti-masker, I’m still wearing it in shops for example. This is just me wanting to understand.
In: Biology
Partly the saying is overselling a bit, masks do help both ways, they’re just more effective at stopping spreading than they are at stopping catching.
It’s because when you cough/sneeze/breath it’s not just gases that leave your mouth, there’s lots of small water droplets as well.
The water droplets either fall straight to the floor because they’re too heavy or they float around and might slowly evaporate away leaving just the virus and whatever else behind.
Masks are very good at stopping droplets which have recently been released but they’re less effective the smaller they get, the droplets are biggest when they’re first sneezed/coughed so that’s when a mask has the best effect.
Also not all masks are equal, if you get yourself a good enough mask then it will basically be just as good either way.
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