 So as the first wave of the COVID-19 pandemic spreads across the United States, where places like New York have passed their peak and are settling down, we're seeing surges of cases and new hot zones form in states in the South and the Southwest. Now as we're seeing these resurgence of cases in these new states, we are again seeing this debate about mandatory face masks. Now we saw these mandatory face mask policies in numerous countries abroad and in hot zone states such as New York City at the start of the pandemic. Now there are ongoing questions about the true efficacy of these masks, about how mask wearing policies are infringement on our rights, and even some people claiming that wearing masks causes harm. Now I ask myself, why is this such an upsurgence of this sort of anti-masker movement? And I get it, since this pandemic started there's been so many unknowns, there's been so much redirection and changing of recommendations, there's been very poor communication from our leadership and our healthcare organizations, so people are frustrated, they're fed up and they question everything they hear, and they want to seek out their own facts. Let's talk about this a little bit. Where is the evidence that public face mask wearing actually helped prevent the propagation of COVID? And it's true, the evidence is all over the place, right? There is first of all very low quality data in general, and depending on which camp you're on, if you're the pro mask camp or the anti-mask camp, chances are you're going to find some data out there that says masks may not do anything or masks may help. And the reality is we're never really going to get high quality evidence to prove whether or not mask wearing to the public is going to definitively affect transmission of COVID. So we got to analyze what we have to the best of our ability, balancing both the risks and the benefits. Now I'm going to get to the evidence angle in a second, but for now let's go over what we actually know for sure. One thing we certainly know about COVID, it is a rapidly spreading and very infectious virus. It spread across the world very quickly and made a lot of people sick and killed a lot of people. There is no debate about that. Secondly, we also know that there is an element of asymptomatic transmission. That is, there are people who are infected with the virus who either have not had symptoms yet or pre-symptomatic, or there are people who've gotten infected and may never have symptoms. And there's definitely a component of transmission that's occurring in that population. Finally, we know that contracting COVID-19 infection has to do with the concentration of viral exposure. That is, the viral load that you're exposed to will dictate whether or not you're going to get infected or you're going to get really sick or you're able to clear the virus without getting infected. We also know that the virus is transmitted primarily through respiratory droplets. That is, pieces of saliva and spit and mucosa from your nears, your mouth, where the virus will sort of hijack these particles and carry over to other people to infect them. There's also a component of aerosolization or airborne infection where the viral particles could potentially hang out in the air after someone's coughed or sneezed or even talked for a short period of time. So based on this, if we can reduce the concentration of viral particles transmitted through someone's oral and nasal cavities to other people, we could potentially reduce the rate of infection. What exactly do we know about masks? Well, first of all, we've been wearing masks in the hospitals and during surgeries for a long time. And it has been proven time and time again that the masks are an effective barrier to prevent the transmission of infectious material. Now, even though they may not reduce it to zero, no matter what type of mask you wear, whether it's a cloth mask, a surgical mask or even an N95, it can significantly reduce the spread and the distance of spread of viral particles from the wearer of the mask. There are several studies that actually evaluated the efficacy of masks when a patient who has a potential virus is coughing and how much that viral particle will be expelled into the environment. And it showed that when you're wearing no mask versus a cloth mask versus a surgical mask, there is a sequential decline in the distance that the viral particles will travel and the concentration of those viral particles. So again, not zero, but it mitigates it. So based on what we know about the properties of the virus and how it's transmitted, the fact that face masks do provide some sort of a barrier for transmission and combine that with a little bit of common sense, it seems that wearing masks would be effective or at least provide some benefit, even if it's marginal. Then the question comes, do we actually have data that face masks would reduce the transmission of a virus during a pandemic or specifically in COVID-19? Now, whatever camp you're on, chances are you're going to find some trial that either shows masks don't do anything or masks may do something. The trials are very heterogeneous, they're all around the map, mostly observational low quality data. However, several of those studies do suggest a potential benefit. Now, I would argue even a potential benefit across a few trials is enough to implement such a policy if we think that it could be effective, especially when wearing masks does not have a lot of harm. Now, one study that caught my eye was recently published in the Proceedings of the National Academy of Sciences and what they did was they looked at Wuhan, China, Italy and New York City in the United States and what they did was plot out the rate of infections per day and they sort of overlay that with when certain measures of mitigation were implemented, such as lockdown the country, stay at home orders and mask wearing. Now, if you look at these curves, if you look at Wuhan, as you can see they had an early surge of infections but they were able to flatten their rate very quickly and again over there they had a lot of simultaneous aggressive measures including quarantine, lockdown, contact tracing, mandatory mask, etc. Now, if we go further down and we see Italy and New York City, here we can see Italy where around March 5th when they started to search. Okay, and here the first line is when lockdown occurred, then you see the lockdown orders and still the curve persisted. Okay, it was not until this sort of round black circle you see when face masks were made mandatory did you see the curve inflection start to occur. Now, let's look at New York. In New York again similarly they had social distancing orders followed by stay at home orders. Despite that the curve persisted and then when mandatory face coverings were ordered you can finally see the curve then started to settle down. Next figure this is plotting New York City versus the rest of the United States. Again, sort of showing the same information in a different type of chart showing daily cases you can see despite social distancing and stay at home orders the number of cases continued to persistly rise both in New York City and in the United States. Finally, when you see mandatory face coverings occur in New York City that's when you're seeing a steady decline of cases and you see the rest of the United States persistly elevated. So based on this data it seems very likely that the face mask order did make a difference and in fact it seemed to make more of a difference potentially than social distancing orders in stay at home orders. Of course it's possible that when that mandatory face mask order was given people in general realized that wow this is a big deal and maybe they're just being extra cautious with social distancing being extra cautious with the hygiene and just not going out and interacting as much so that sort of surrogate effect may have played a role as well hard to know. Now despite the lack of definitive data I would argue we have enough data to make us optimistic that mask wearing does help and it comes with very little downside and of course it's going to be a finite period of time where we're doing this so why not why not just wear the mask and suck it up for now. Now I get it nobody likes to wear a mask I mean I hate wearing masks I don't like the way I breathe in it it's uncomfortable you know you can't really recognize people there's you know no social cues and of course nobody wants to wear them but we do it because it's probably the one thing that we can all do to contribute to the slowing of this thing and finally there is this narrative being pushed that mask may actually cause harm. Now first of all there's no data to suggest that yes it's uncomfortable yes you may have a sensation of shortness of breath but unless you have like severe underlying lung disease or you're acquiring oxygen wearing a mask is not going to reduce your oxygenation you're not going to build up with carbon dioxide you're not going to increase your risk for pneumonia or fungal infections all these things there's absolutely no data to suggest this. Let's just look at the hospitals right now we've been wearing masks in the hospitals forever and that's because we know that wearing a mask reduces the risk of us transmitting our germs to our patients we're wearing masks throughout the whole day last I heard there was no health care workers or doctors or anybody indicating that you're getting sick from wearing their masks in hundreds of years so the notion that masks are harmful is bogus certainly if you were going to go under the knife for a surgery you would want your surgeon to wear a mask am I right so why should we ask less of anybody else in the public during a pandemic if it means reducing the risk of transmission and the health of other people in the end we can have this debate ongoing will we ever have a hundred percent answer no but come on what is the big deal if there's even a small chance we can reduce the rate of infection in the spread of this disease so if you're in a surging region right now the mitigation measures that we know work hand-washing you know social distancing and wearing a mask so please please just for now just do it