The Untold Truth Behind Face Masks and Covid-19

hey 42 here don't wear a mask wear a mask don't wear a mask no wait do wear one at all times except here here and maybe there the advice around wearing face masks to reduce a spread of covert 19 coming from some governments large ngos and igos has been at best confusing and the worst outright contradictory that's why i want to dive deep into the science behind wearing masks to bust some common myths and answer two simple questions does wearing a face mask reduce the spread of covert 90 and is it something we should all be doing right now well to sort of answer the second question i'm not going to tell you whether or not you should wear a mask it isn't my place to do so you are hopefully a responsible person and i'm sure you'll assess the science way up all the advice from various sources and come to your own conclusion based on your unique circumstances but how can you even begin to make that call without clear science-backed information instructing the general population to wear a face mask has never been a popular decision even when it is ostensibly for the greater good in 1918 towards the end of world war one the spanish flu now known to have been the h1n1 influenza virus swept across the world infecting one third of the global population and killing up to an estimated 50 million people during the height of the pandemic governments around the globe introduced restrictive measures to curb the spread of the killer virus especially to protect frontline troops from falling ill all the way from no spitting rules and closing schools to yes you guessed it mandating the wearing of face masks most people an estimated 80 percent complied with the mask wearing mandate but there were rebellious splinter groups such as the imaginatively named anti-mask league that formed in san francisco who outright refused to don one citing their discomfort and restriction on breathing some people also felt that masks made day-to-day business awkward and unprofessional but how did this mask mask wearing experiment play out did it have any effect on quelling the spanish flu's virulence or slowing its spread not really this graph shows the results of a study published in 1919 by the california state department of health comparing weekly death rates per 100 000 people in stockton where the wearing of masks was made compulsory and boston where it wasn't as you can see there's little to no difference between the curves however there's more to this data than meets the eye and with our now greater understanding of epidemiology and the benefit of hindsight there are some vital lessons to be learnt from this story that we can apply to our current situation to help us kick the crap out of covert firstly the masks that were most commonly worn during the spanish flu were made of gauze advanced respirators and even basic surgical masks typically three layers of polypropylene sandwiched between non-woven fabric were a distant invention of the future gauze on the other hand is well a thin fabric mesh full of holes so large they are easily visible to the naked eye that instantly puts a huge droplet-shaped hole in what conclusions we can draw from this data to make mata's worse basic education for the general public on how to wear a mask including not touching it and keeping it dry was practically non-existent at least outside of medical environments and as we'll soon discover how you wear a mask is far more important than whether or not you wear one because incorrect usage can actually increase your likelihood of catching and spreading a virus michael mina is assistant professor of epidemiology at harvard t.h chan school of public health and a core member of the center for communicable disease dynamics he is joining us from the forum at harvardchan i asked michael why he thinks masks weren't all that effective during the spanish flu i would say it's pretty hard to compare 1918 with today both from the quality of the masks but also i haven't seen particularly compelling evidence anyway of just how just how reliably people are actually wearing them so fast forward to our current situation as far as we know this coronavirus sars cov2 which causes the disease called covid19 spreads primarily through respiratory droplets which can be projected as far as eight meters through coughing and sneezing but surely if i touch a droplet from an infected individual that's landed on a surface and then touch my face the chance of me catching covert is still fairly low right this is called fomite transmission and provided the droplet which is now on your hand makes contact with a mucous membrane such as your eyes the inside of your nose and mouth you just put yourself at considerable risk because it's estimated that each droplet contains thousands of coronavirus particles known as virions when outside the body and theoretically all it takes is one virion to enter your system evade your biological defenses and bind with one of your respiratory cells receptors to cause infection although in the real world it will usually take a lot more than just one virus particle to cause infection you may be thinking that you rarely if ever touch your face but you probably do so much more than you realize because it's an action that's often autonomic meaning you're not consciously aware you're doing it a 2015 study in the american journal of infection control found that participants touched their face an average of 23 times per hour and 44 of those touches were on mucous membranes but subconsciously prodding your mucous membranes may not even be required in the first place one study demonstrated how smaller viral particles called aerosols can remain suspended in the air for around 14 minutes in laboratory conditions though this time would vary wildly in the real world depending on atmospheric conditions certainly we have pretty good evidence at this point that aerosolized virus is a mode of transmission and certainly within minutes i i don't see any anything that would imply that it uh couldn't exist and i actually would suggest that um given the right type of super spreader who's maybe really aerosolizing a lot due to some some physiological differences that maybe they have or just how high the viral titer is in the respiratory tract i wouldn't be surprised if it's even quite a bit longer than that half hour you know the virus we know uh does exist on us on surfaces and uh and it can similarly exist suspended in the air and simply breathing in infected aerosols may be enough to cause infection and it's not just those who are obviously ill with covid19 coughing and sneezing all over the place who are spreading it as you may have heard people who test positive for covid can be asymptomatic we're still unsure about what percentage of those with the disease are asymptomatic but studies have estimated anywhere from 18 to 80 percent quite the range i know i asked michael mina what his take is on this my guess is probably at least 50 percent of people are for all intents and purposes uh asymptomatic and i wouldn't be surprised if in terms of the number of people who recognize that they have been infected by the time that they're actually transmitting uh without kind of looking back and saying oh yeah i might have been sick at that point uh maybe it is up around 70 or 80 percent who who just don't actually recognize that they're sick at the time that they're able to transmit the virus but the important takeaway is that individuals who are asymptomatic and pre-symptomatic meaning they are yet to show symptoms can still spread this particular coronavirus you may be wondering how that's even possible if they aren't coughing and sneezing aerosols and droplets everywhere it's a good question but it turns out covered 19 has unique properties that make this type of transmission a lot more likely it produces an unusually high number of viral particles in the upper viral tract that's the mouth nasal cavity pharynx and larynx and these can very easily shed outside of the body simply by talking compared to seasonal flu research has found that covid19 is expelled from the body through talking at a much higher rate in pre and asymptomatic patients and every time you talk even quietly you're spraying thousands of tiny droplets into the environment around you after all the act of talking is essentially just expelling air through a very damp chamber full of saliva mucus and tiny bits of your breakfast and if you talk loudly or shout you can propel these droplets just as far as a cough or sneeze potentially infecting many others around you in a public space but don't think you can just avoid talking to people because as michael mina explains there are a couple of other ways that asymptomatic people can spread covet 19. it's not just from talking it could also be from coughing a lot of times people with covet have a dry cough so you could have a cough there but in general it's going to be one of those but it can even just be breathing but talking is um does create more of a of an expulsion of sort of a high energy wave out of you so it's fairly self-evident that wearing a good face mask can reduce the expulsion of these tiny aerosolized virions and larger droplets and indeed using nifty camera tricks a few studies have been able to demonstrate just how great face masks are at almost entirely eliminating droplet expulsion and the formation of aerosols as shown here by this brilliant footage captured by the university of new south wales in sydney and since we don't yet know what percentage of people are asymptomatic and the very nature of being pre or asymptomatic means that neither you nor anyone around you can identify if you actually have covert 19 wearing a face mask seems like a really sensible precaution by simply wearing a mask in public you vastly reduce the likelihood that you'll infect those around you if you happen to have covered but not realize it don't believe me one man traveling from china to toronto had a dry cough the entire flight and tested positive for covered 19 after he landed thankfully he had been wearing a face mask during the journey the result all 25 people sitting closest to him on the flight tested negative for covert 19 afterwards there are many other such examples to name just one two hairstylists in missouri who were ill with covert 19 but wore face masks interacted with and cut the hair of 139 clients whilst they were real but when all of those clients were tested afterwards not one of them tested positive for covert 19. a very recent study from oxford university published in late june concluded that yes when made of optimal materials which we'll get into in just a moment face masks are highly effective at reducing the spread of covert 19. however this effectiveness relies on proper education on and widespread adherence to correct mask usage good hand hygiene and social distancing and this sort of consistent messaging is not something we've seen up to now which the study highlights as a contributing factor as to why we've yet to see any irrefutable correlation between widespread mass adoption and lower transmission rates are numbers but people are beginning to pay attention the percentage of americans now wearing masks in public was up to 67 in july and around 84 of italians are wearing them despite neither of these two countries having an established culture of wearing face coverings no doubt a lot more data will emerge over the coming months okay so we're fairly darn sure that wearing a face mask can stop you from spreading covet 19. that's great but what you might want to really know is whether wearing a mask reduces the likelihood of you catching it if some reprobate coughs in my face when i'm wearing the correct type of mask will i get away virus free the truth is we still don't know that yet what we can quite confidently say is there is no face covering that will guarantee you won't catch any virus even if you're ready to go full diving helmet the only truly scientific way to test whether masks protect the wearer as well as those around them would be to gather up a bunch of covered positive people and ask them to talk and cough directly at two groups of people in two separate rooms one group who are wearing face masks and another who are not for obvious reasons that's not ethically possible and this gap in our knowledge is probably a large part of the reason you're seeing a lot of mixed advice on the efficacy of face masks as a means of protection all scientists can really do is look at real world examples and attempt to extrapolate correlations something they haven't been able to do conclusively just yet but to state the obvious having material in front of one's nose and mouth creates a physical barrier between your mucous membranes and the outside world that will very likely filter out at least some of those nasty virus particles there's a long and storied history of this in medical environments and there's strong scientific data supporting this which is why ppe is so strictly mandated in hospitals and nursing homes this isn't just to reduce onward transmission it's to protect the well-being of those vital health workers caring for people who are ill with covid but compared to a full ppe kit which includes a gown n95 respirator goggles face shield and rubber boots your mileage is going to vary significantly even if you wear a decent face mask your eyes are still an unguarded mucous membrane on which tiny aerosolized virus particles can settle and infect you but don't sweat professor michael mina thinks that this transmission vector through the eyes is not something we should all be getting worked up over in real world environments i don't know how much i subscribe to the eyes being a major form of transmission or acquisition i think that it's probably unlikely if you're immune compromised or cancer or something like that then sure wear goggles if you know to give you excess protection but my feeling is it's not going to be a main mode of transmit or acquisition put simply a face mask offers the wearer a higher degree of protection than not wearing one even if we aren't entirely sure what that degree is yet but as we've learned from the spanish flu material matters if your face mask is made of swiss cheese or is otherwise porous it's going to do very little in the way of protecting you and preventing you from passing on virus particles to others what may surprise you however is that you don't need medical grade face masks to help protect others and yourself any tightly woven cotton t-shirt crudely cut out and fashioned into a mask preferably folded to create a double layer will significantly reduce your capacity for transmission in both directions don't want to chop up your precious iron maiden 1981 tor t-shirt fear not a recent study conducted at wake forest baptist medical center in the u.s suggested that some easily attainable materials such as heavyweight quilters cotton and even vacuum cleaner bags preferably unused provide fantastic protection filtering out as many as 79 of particles 0.3 to 1 microns in diameter the typical size range of aerosolized virions that's actually more than surgical masks which the same study found to stop 62 to 65 of virus particles that's because surgical masks can be more porous than your typical dense cotton fabric and don't protect quite so well against the smallest of aerial sliced particles as they are primarily designed to stop large droplets they're still a fantastic choice though which you definitely shouldn't pass over because keep in mind this study focused on filtering the tiniest of virions as we saw in the footage earlier surgical masks are more effective at filtering large droplets than cloth masks on and so can offer more well-rounded protection lightweight bandanas and scarves were amongst the materials that provided the least filtration power and would not be widely recommended as a suitable face covering in fact a recent study by duke university researcher martin fisher found that using a neck fleece actually increased transmission by an additional 10 percent compared to wearing nothing at all a bandana was found to make little to no difference to filtration the mass that offered the most protection was of the n95 variety which is not at all surprising its name literally comes from the fact that it filters out 95 of particles in this particular study however it felted 97 but before you rush out and buy an n95 respirator consider that they are currently in extremely high demand primarily by those on the front line treating covert patients they aren't easy to get hold of even if you did manage to find a couple listed in some highly questionable rarely visited corner of the internet yeah a small tip here if your face mask provider also sells discounts dog food give it a miss even if they were easy to source what have i told you that you're still better off covering your face with something like a t-shirt surgical mask or any other densely woven material instead you see some variants of n95 respirators especially those used in the construction industry but some that are used by medical professionals too have an outlet valve on the front that's designed to allow unfiltered air to escape meaning that they offer little to no protection to those around the wearer many health professionals are strongly advising against the use of this kind of mask because they are ineffective in reducing the spread of covert 19. the same goes for any other masks you can purchase that feature an outlet valve like those cotton ones you've probably seen popping up everywhere recently far from protecting those around them whereas if these kinds of masks are essentially exhaling highly targeted streams of unfiltered air potentially containing millions of coronavirus particles and anyone who happens to be nearby that's why disney has wisely outright bans the use of masks that contain a valve in disney world theme parks they've also specified that all masks worn must contain at least two layers of material even more important than the kind of mask you wear is how you wear it a lot of governments right now are mandating the wearing of face masks in indoor public spaces but if most people are unsure of how to wear masks properly or simply refuse to follow the correct procedures then they may as well be walking around licking lamp posts and if that's how you roll anyway then i strongly advise you to put your weird hobby to bed until we're no longer in a global pandemic thanks like i said earlier wearing a mask incorrectly can put you and others around you at higher risk of catching this coronavirus than not wearing one at all and i know it can be frustrating when you see people wearing masks incorrectly and for example grabbing the front of their mask and rearranging it every two minutes but here's a quick fire checklist of some really solid mask hygiene practices you can follow so at least you can set a good example wash your hands before pushing on and removing your mask only put on your mask by touching the ear straps and pulling it over the ears so it's snug and secure if the mask has a metal strip at the top pinch it to create a better seal around the nose never touch the material part of the mask after you've put it on especially when in public because it could be saturated with coronavirus particles that will then be on your fingers and could lead to formide transmission to yourself or others if it helps you remember pretend that the material part of your mask is made out of lava and if you touch it your hand will turn into a lump of charcoal if you do need to remove your mask in public remove it by the ear straps only and place it on a surface with the outside or front side of the mask facing down touching the surface make sure no surfaces come into contact with the inside of your mask if your mask gets damp or wet which can happen after a few hours of use because of your breath you need to replace it with a fresh mask or go home and either discard it or wash it because a damp mask offers significantly lower protection only remove your masks via the ear straps after you take your mask off either put it in the washing machine or dispose of it and then wash your hands for at least 20 seconds with soap and water and of course there's the issue that when people wear a mask they may feel as though they instantly become a quasi-coveted terminator and are hence magically invulnerable to the virus and get excessively cocky engaging in behaviors that actually put others at more risk like ignoring social distancing or attending large gatherings you know when you're casually comparing mangoes in the supermarket and out of nowhere some guy shoves his big mask covered beak about two millimeters from your face to reach over and grab something well don't be that guy just remember wearing a mask is only one piece of a larger puzzle in the fight to stem the spread of this virus it doesn't make social distancing or good hand hygiene any less important all of these elements are needed if we're going to slow this thing down until there's an effective vaccine or perhaps a fast and reliable quantitative home testing kit short of a vaccine giving everyone a test that they can use every single day that can tell them if they're transmitting the virus will essentially create a semblance of herd immunity and it could actually our calculations suggest that it could very rapidly cause the virus to be depleted out of a population if we had everyone or being able to use or most people being able to use a test for transmissibility every morning or every other morning that's all very well 42 but i've heard that wearing a face mask can reduce oxygen intake whilst increasing carbon dioxide intake from your own exhalations and can thus cause hypoxia or hypercapnia so that if you aren't careful you'll keel over and die like a strangled salmon well if i may be blunt for a second this is absolute rubbish and no more than internet gossip and fear-mongering unless we're talking about young children or those with pre-existing breathing complications there is no chance that wearing a simple cotton or surgical mask will cut off a sufficient quantity of your oxygen intake to cause any ill effects even if you do wear it all day long not even n95 respirators are known to cause hypoxia or hypercapnia in healthy adults surgeons all over the world have been wearing them not to mention other extremely tight and restrictive face coverings for decades now sometimes all day long and we don't see mass die-offs of surgeons on the headlines it may feel like your breathing is obstructed when you put on a mask but that's most likely because mask wearing is new to you and you're not used to the sensation because yes obviously your breathing is restricted a little with a mask but there's simply no reputable evidence that this is dangerous in fit and healthy individuals of course please do remove your mask if you start to feel light-headed for any reason so to summarize as far as we know the main benefit of wearing a face mask is not to protect yourself it's to prevent you from passing coronavirus particles to others who may be more vulnerable than you or who may pass it on to others who are and i think in times like this it's nice to go out of your way a little to be caring and compassionate to those in society who may not be as fit and healthy as you and i and because it's close to a certainty that covert 19 spreads pre and asymptomatically simply wearing a mask is a good way to do your bit to reduce onwards transmission and help put this frustrating chapter of humanity behind us so we can all stop wearing our pajamas 24 7. because let's be honest they probably needed a damn good wash after week one of lockdown and by now they might be harboring the first stirrings of the next global pandemic i'm just trying to help shed some light on an area that i think has been confusing for a lot of people thanks to the endless onslaught of conflicting guidance from every angle i know a lot of people have strong opinions on wearing masks many of which are understandable so unless you're in a place where your government has mandated the wearing of one which is soon to be most places anyway whether you do wear a face mask is ultimately your call to make but from my point of view mass mask adoption is almost certain to save some lives and any downsides are at least for the vast majority of people negligible either way good luck out there and thank you for watching thank you to the team at google and harvard t h chan school of public health who helped make this video possible and especially dr michael mina phd for his invaluable time and expertise

Channel: Thoughty2

Views: 1,542,124

Rating: 4.647306 out of 5

Keywords: coronavirus, covid, covid 19, virus, pandemic, coronavirus news, coronavirus pandemic, coronavirus update, masks, face masks, wearing masks, cotton masks, surgical maks, covid-19, coronavirus outbreak, corona virus, coronavirus explained, coronavirus prevention, corona virus update, covid-19 news

Id: MVcdyPf5mKQ

Length: 28min 38sec (1718 seconds)

Published: Wed Aug 19 2020