Which mask is the right mask to wear?

Do you wear a face covering when out in public spaces? Thank you. But to add another layer of complexity, the type of face covering you wear matters. A recent study from Duke University (my alma mater!) demonstrated that bandanas and neck gaiters may actually be causing more harm than good. The problem is the porous nature of the fabric. The study demonstrates that if you sneeze or talk under a gaiter or bandana, the larger droplets may actually disperse into smaller droplets, which are lower in weight and mass. These lighter and smaller aerosolized droplets are more apt to linger in the air (which is the main avenue by which COVID is transmitted).

Based on the study results, the most protective masks (protecting others from you!) are N95 and surgical masks. But everyone in the world wearing N95 or disposable surgical mask is not sustainable. So, default to a cotton mask; they are still quite effective (reducing your expelled droplets by 10-40%) due to the multi-layers and tightly knit cotton. A good rule of thumb? If you can see through it when put it up against a light or you can blow through it easily, you are not protecting anybody. And continue to socially distance to further reduce your rate of transmission.

Remember, this pandemic has been so hard to contain because of asymptomatic carriers. And masks keep these carriers from unknowingly spreading the virus when they cough, sneeze or just talk.

I know this virus is complicated. But the guidelines are not. Wear a mask. Wash your hands. Socially distance. I’ll share something I said to my own mother the other day: “Just because it’s not convenient for us, does not mean we should ignore the science.” I’m not telling you what mask to wear. I trust and believe you are trying your best. But I want to share the science as it evolves, so you can make an informed decision. This study demonstrates that the right face covering works. And if we want this pandemic to subside, the-right-mask-wearing is the way to do it.

Thanks for listening and spread the word (not droplets). 😉

Love, Dr. Yang

Do masks restrict your breathing?

Warning! Math coming your way!
I wanted to dispel a common claim that masks disturb breathing.

A coronavirus particle is 120 nanometers (nm) in diameter. Oxygen is 0.120 nm and Carbon Dioxide is 0.232 nm. To interpret these numbers very clearly, oxygen is 1000 times SMALLER than the coronavirus particle and carbon dioxide is 517 times SMALLER than the coronavirus. Meaning that in the same little hole that one coronavirus might be able squeeze through, 1000 oxygen molecules can get in and 517 carbon dioxide molecules can get out.

The pore size in N95 masks is generally 100 to 300 nm. Meaning the average single pore will allow 1667 oxygen molecules in and 862 carbon dioxide molecules out.  Other masks like surgical or cloth masks have even higher pore sizes. Therefore, it is not mathematically sound to say that that a mask restricts oxygen or carbon dioxide flow. In fact, it is impossible. It doesn’t mean that the wearer does not feel restricted (psychological effect), however, the math and physics are not consistent with that feeling.

So why wear a mask? The good news is, you don’t have to worry about the 120nm coronavirus particle itself because the virus collects together in larger droplets from your respiratory tract. The average size of the droplets is 1000 nm. And a mask is quite effective at blocking the droplets you are exhaling, coughing, or sneezing. So, the mask prevents the droplets from your mouth and nose from going anywhere past the mask, thereby leaving no SARS-CoV-2 particles in the air for someone else to inhale.

So woo hoo! By mask wearing, you can breathe freely AND keep you respiratory droplets to yourself. It’s like magic! Except it’s really just math.

We have the ability to end the pandemic in 4-6 weeks if everyone would wear a mask 100% of the time in public! AND we could all get back to our lives of going to the restaurants we love, traveling, going to the beach etc. so the economy would recover much sooner IF WE ALL JUST WORE MASKS!

Wear a mask, save a life. Maybe also your own. And please share the math!

Love, Dr. Yang