Does wearing a mask really help?

Does wearing a mask really help protect against Covid-19? Yes it does. As I watched the Bob Dole funeral on TV in DC Friday, I was struck by the sight of everyone wearing a mask– the audience, the speakers (except when they were at the podium), the choir, and Elizabeth Dole and her family. No doubt masks were required for attendance, but there was no partisan difference in who showed up and wore their masks.

One way we can protect ourselves as variants surge is to wear a mask. What is surprising to me is that most people still do NOT wear their masks properly. They either wear a mask that doesn’t provide much protection, like a cute decorative cloth mask, or it slips to the end of their nose  or below their nose, invalidating the whole purpose of the mask itself. If you can’t wear it over your nose, you might as well not wear it at all.  The other thing people do is to drop the mask when they want to speak! That also makes little sense, since the whole purpose of the masks is to keep potential virus from escaping from one person to another.

There are a variety of masks available, ranging from a simple cloth mask to a N95 that is actually fitted to your face (this fitting mainly happens in a medical setting so you can disregard that in the chart below).  I have preferred cloth masks because they can be washed and used over and over, and they are attractive, but the chart below gives you a general idea of the amount of protection you receive from different types of masks. (It’s difficult to enlarge and view so I will explain its contents below.)

Source is Asit Mishra – @akm5376 on Twitter – Mishra is an Engineer and an Indoor Climate Researcher.

The times in this chart are Mishra’s best estimates for time to reach an infectious dose from contact between individuals wearing different types of masks. The Y axis on the left shows infectious individuals wearing masks that vary from Nothing (on top)  to an N95 fitted (on the bottom); the X axis along the top shows the type of mask the vulnerable person is wearing from Nothing (on top left)  to N95 fitted (on top right). The numbers in RED indicate contact with the Delta strain. (The Omicron strain is  not included in this graph but is even more contagious.)

What does this chart mean?  It’s just an estimate, but it demonstrates that if a person who is infected with the Delta virus (whether they know it or not), is wearing a cloth mask, is in contact with a vulnerable person also wearing a cloth mask, the estimated time to an infectious dose from one to the other can be short — perhaps  only 10 minutes, depending on how close they are to each other. That time can stretch to 13 minutes to infection if the vulnerable person is wearing a surgical mask (one of those blue masks) and 68 minutes if the vulnerable person is wearing a N95 mask.  If both individuals are wearing N95 masks, the time to infection from the Delta strain may be as long as 6.8 hours.  These number are not meant to be precise — they just give us a general idea of the protection we can get from different types of masks if they are worn correctly.

There is conflicting information about who should wear N95 or KN95 masks and where they can be purchased.  Not every website offering masks is legitimate and not everyone needs the N95 type masks (“surgical N95 respirator masks” should be reserved for health care workers). Most other types of masks will protect you if you are not in situations indoor with unvaccinated people. This CDC website provides excellent information to answer all your questions. Check it out before you purchase a mask.

Bottom line? Wearing a mask can protect you from Covid-19. Whether you wear a cloth mask or a N95  (or a KN95 – see difference), it’s important to find a mask that suits your situation.  You may also want to have several types of masks handy. Are you around people most of the time who are all vaccinated? Perhaps you are going to an event where you don’t know who is vaccinated? Check out this article for information about where to find the right mask.

The good news is that we do have solutions to this pandemic. Getting vaccinated and boosted is first and foremost to spare yourself from serious disease and hospitalization. But wearing masks, even though we are sick and tired of them, is helpful until there is so little virus circulating that the danger is minimal. Let’s hope that time comes sooner rather than later!