Masks Also Protect the Wearer
From the very beginning of the pandemic, we knew that wearing a mask protects other people from your respiratory droplets. But shouldn’t masks also protect the wearer? At first, science could not answer this question, but it is probably true. CDC recently updated their recommendations on the masks to be noted that the protection, it seems, works in both directions.
They say:
Masks also help to reduce the inhalation of these droplets by the user (“filtration for personal protection”). The public benefit of camouflage to control SARS-CoV-2 comes from a combination of these effects; The benefits of individualized prophylaxis increase with the number of people consistently and correctly using masks.
This understanding does not change the essence – we should all wear masks when we interact with people outside our home – but it does help us understand where the protection comes from.
For example, if you are heading to a place where you know many other people will not wear a mask, does it matter if you wear it yourself? If masks only protect others from you, you are doing other people a little favor, but not helping yourself. However, if the new interpretation is correct, wearing a mask in this situation will probably really help protect you.
So what has changed?
First, scientists studied how masks work, including how droplets behave when faced with different types of masking material. Droplets can adhere to, repel or become trapped between fibers. Even small particles can be trapped by masks. (The New York Times has a great visualization of how this works .) This lends support to the idea that masks help no matter which side the virus-infected particles are coming from.
Another line of evidence is a series of case studies: places where more transmission of the virus could be expected, but since the use of masks was common, the transmission rate was particularly slow. These studies included hairdressers who worked with symptoms and an outbreak on board an aircraft carrier. By examining this type of research, we cannot be sure how much protection the wearer’s mask offered versus everyone else’s masks, but it adds to our understanding that more masks make the environment safer.
The bottom line is that masks work even if they’re not perfect. N95s perform better than sheet masks, but many sheet masks are still very effective, depending on their design. (The more layers and more threads, the better the protective mask.) So wear a mask even if others are not; it will help anyway.