How N95 Masks Stop Viruses
HTML-код
- Опубликовано: 11 май 2020
- Preventing a pathogen from entering our respiratory system, at first glance, may seem obvious. The first thought might be to trap them by preventing particles from moving through a filter. But looking deeper at the problem reveals the true scope of the challenge.
With every normal breath we take, we inhale around a half-liter of air. The pressure difference between the atmosphere and our lungs during inhalation, peaks at around 8 cm of water. For comparison, a typical shop vac can pull a vacuum of around 200 cm of water or about 25 times that of our lungs.
Pathogens vary widely in size with bacteria generally ranging in size from 1-20 um to viruses which can range from 17nm up to 750nm. The rhinovirus that causes the common cold, for example, is around 30nm in diameter, while HIV, SARS-COV-2, and some strains of influenza hover around 120nm.
TYPES OF RESPIRATORS
N95 respirators are part of a class of respiratory protection devices known as mechanical filter respirator. These mechanically stop particles from reaching the wearer's nose and mouth. Another form of respiratory protection is the chemical cartridge respirator. These are specifically designed to chemically remove harmful volatile organic compounds and other vapors from the breathing air.
Both classes of respirators are available in powered configurations, known as powered air-purifying respirators.
N95
The N95 designation is a mechanical filter respirator standard set and certified by the National Institute for Occupational Safety and Health in the United States. The number designates the percentage of airborne particles removed, not their size. While ratings up to N100, that can filter 99.97% of airborne particles exist, N95 respirators were determined to be suitable for short-term health care use, in the 1990s.
Other designations include oil-resistant R and oil proof P respirators, which are designed to be more durable and maintain filter effectiveness against oily particles in industrial use. Surgical grade N95 respirators possessing fluid resistance were specifically cleared by the United States Food And Drug Administration for medical use.
HOW THEY WORK
Modern mechanical filter respirators work, not by ‘netting’ particles but rather by forcing them to navigate through a high surface area maze of multiple layers of filter media. This concept allows for large unobstructed paths for air to flow through while causing particles to attach to fibers due to a number of different mechanisms.
In order to achieve the high surface area required, a non-woven fabric manufacturing process known as "melt-blow" is used for the filter media. In this technique high temperature, high-pressure air is used to melt a polymer, typically polypropylene, while it’s spinning. This produces a tough yet flexible layer of material composed of small fibers. Depending on the specifications of the layer being produced, these fibers can range from 100um all the way down to about 0.8um in diameter.
How these fibers capture particles are determined by the movement of air through the filter media. The path of air traveling around a fiber moves in streams. The likelihood of a particle to stay within this stream is primarily determined by its size.
The largest particles in the air tend to be slow-moving and predominantly settle out due to gravity.
Particles that are too small for the effects of gravity, down to around 600 nm, are primarily captured by inertial impact and interception.
Inertial impaction occurs on larger particles in this size range.
In contrast, particles below 100nm are mainly captured through a mechanism known as diffusion. Random movements of air molecules cause these very small particles to wander across the air stream due to Brownian motion. Because the path taken through the filter is drawn out, the probability of capture through inertial impact or interception increases dramatically, particularly at lower airflow velocities.
EFFICIENCY
Because of the complex, overlapping methods by which particle filtration occurs, the smallest particles are not the most difficult to filter. In fact, the point of lowest filter efficiency tends to occur where the complementing methods begin to transition into each other, around 50-500 nm. Particles in this range are too large to be effectively pushed around by diffusion and too small to be effectively captured by the interception or inertial impaction. This also happens to be the range of some of the more harmful viral pathogens.
Interestingly, the more a respirator is worn, the more efficient it becomes.
FLAWS
The weakest point on any respirator is how well it seals against the face. Air will always pass through facial leaks because they offer much lower resistance than the respirator, carrying particles with it.
SUPPORT NEW MIND ON PATREON
/ newmind
SOCIAL MEDIA LINKS
Instagram - / newmindchannel
3:53 Forbidden cotton candy
nothing forbidden about it at 4:00. It's stock footage of actual cotton candy being made as a illustrative stand in for the polypropylene meltblown process. After reading I don't know how many scientific papers, patents, and articles about this stuff over the past few months I can say that it's actually a really good substitute for visualizing the process, except in a cotton candy machine it's centrifugal force spinning the molten sugar out but in the meltblown process it's hot polypropylene being extruded with pressure from small holes which is then entrained in a jet of hot air.
@@Muonium1 you schould still not eat the polymer fibres
@@Muonium1 oh come on, its forbidden because you can't eat it
@@Muonium1 nothing is really forbidden in the internet when it comes to knowledge, you only have to go more deep and search longer to find it
The Home Depot employees always kick me out when I start eating it
That outro b-roll is top notch
So.. same process as making cotton candy.
You make some of the best and most interesting videos on RUclips, and not one beg for likes and subs. That crap gets so old.
I see what you did there.....
Nice
The fellow at 7:17 doesn't realize that he is wearing it wrong. The bottom elastic goes below the ears and the top elastic goes above the ears.
He has fortune cookie ears now as a result.
Lawn Man cracked me up this comment 😂
Any mask, N95 or not, which has bands or ties, NOT ear loops, is properly worn by putting the top tie/band at the crown of your head and the bottom tie/band at the nape of your neck.
This is the way that manufacturers tell to wear them in their instructions in the box and on their web sites.
This insures that the top of the mask is pulled upward and backward diagonally, not just backward. The lower tie/band pulls the bottom of the mask back against your chin.
If the mask does not have ear loops, there is no tie/band that is placed anywhere near your ears. They go at the crown of your head and at the nape of your neck.
Masks with ear loops often cause gaps at the side of the face because the fabric is not pulled upward and backward properly to stretch out the side material and flatten the gaps.
You see this happen almost all the time when someone is wearing a mask which has pleats and is rectangular in shape before the pleats are pulled out. Pulling the top back to the ear does nothing to flatten the mask at the side of you face. If ear loops were not used on these sort of masks - which the majority of people wear - and instead there was a top and bottom tie/bank, the masks would fit better and would draw far less air around the edges of the mask but, instead, through the fabric of the mask.
N95 masks almost always have bands or ties, not ear loops.
Take a look at multimedia.3m.com/mws/media/1448498O/wear-it-right-putting-on-your-respirator.pdf
That's correct Robert, thanks for pointing this out.
Awesome Awesome! I have alot of filter experience from my Past Hospital HVAC contracts, Static filter and UV are very powerful mechanisms of filtration.
Wow this channel really exploded in size. Congrats man, keep up the great videos
Your doing pretty good on those subs bud keep up the good work
Excellent overview on protective masks, particularly N95 masks. A must see video for all to see.
This should be broadcasted on every television about covid air filtering and general air filtering.
One of the most informative videos on the RUclips 👍✌️
If you told me back in May 2019 that by May 2020 I'll be incredibly into and fascinated with quality face masks and 60% alcohol hand sanitizer, I would have thought your crazy.
Today, I carry hand sanitizer with me at all times and I'm really into my N95 and KN95 masks.
She explains the the world to her past self and it halarious
ruclips.net/video/Pbdk_lBCxJk/видео.html
And by May 2021 you can look at data all over the world and see mask has not stopped anything.
Really..how long are you going to live in fear? Have you stopped eating fast food because heart disease is the number one killer
what's up with the dude kitesurfing?
Nice video. Can you do one on the Hepa house filters?
Btw, the mucus membrane of our nose is a good defense as long as we don't get too dry such as winter air.
7:17
Ears : Am I joke to you?
It's very important to note that the effect mentioned around 6:00 that "the more a respirator is worn the more efficient it becomes" is really only relevant when the mask is being used to filter HUGE amounts large suspended particles in air such as wood dust in a shop, and it is definitely not the main mechanism of mask degradation at play for masks worn for eg. aerosolized viral particle protection. The main mechanism for mask degradation worn in the clean air of for instance an office or grocery supermarket is going to be the neutralization of the electrostatic potential of the mask's electret layer. The high humidity of exhaled breath will allow electric charges to be conducted away from the electret charged fibers and reduce the mask's efficiency for particle filtration over the time noted in the video. Immersing an N95 in any liquid, eg. sterilizing alcohol solution, will immediately destroy the electret layer and reduce the efficiency to likely below 80% filtration of 300nm dia. particles.
The reviews are professional, are you Chinese?
@@kohinata2656 wtf are you talking about
@@kohinata2656 This isn't a review lol.
^^^ this and I would like to add this
The amount of people constantly touching the mask they are wearing is unbelievable, STOP TOUCHING THE MASK. If you are infected you have just transferred the virus to your fingers and on to what ever surface you touch after. A door handle, your car steering wheel, tv remote. think about what you have touched in the last five minutes.
I think the masks are contributing to the spread more than you realize.
@@DVXCine if masks were contributing to the spread more than reducing it we should be seeing rampant infection in East Asia where mask wearing has been custom since before the outbreak and little growth in places like the West where mask wearing is uncommon and even discouraged until a few weeks ago. The reverse is true.
amazing vid mate. One note: you should end with someone showing how to wear the N95 mask properly.
As usual excellent content
Thanks for the info! 👍
Excellent video. Resumes and debunk a lot. Thanks.
These videos are really good.
The importance of fit is why I see no point in those rectangular masks with the elastic on either end, they never seal against the face at all.
You are exactly right. If there is any air leak then it is pointless when it comes to biological agents.
But if you cough or sneeze wearing any kind of mask, others are protected. And you could be infected and not know it. Its like herd immunity, if everyone wears one then it works better.
You’re correct about those rectangular masks. Their purpose is to stop or slow YOU spreading pathogens to OTHERS, not to stop them getting to you in the first place.
Try creating an extra seal around the mask type N95 with two sided tape to prevent air leakage. Just an idea that's all. Stay safe!
@@FffffffffffffffffffffffffffffL really sneezes and coughs are high pressure expulsions and will blow out the sides of any mask making it pointless
The melt blow machine looks like a candy floss maker! Great vid BTW. Thanks. Off to Amazon to get some N95 masks now!
A very good one, thanks
Very interested and informative
In the context of sars-cov2 is it not fso that masks fitted with valves only protect the wearer of the mask, not the people in the vicinity. When used in a department where all patients are already infected, this might be less important though I would like to ask the question if contamination with other viruses the wearer could be spreading could be an additional burden for the patient.
Viruses don't abide by social distancing. People do. This is social/people control. Not virus control. Research the scientific name for the common cold.
~boB
Bob Good Daze that is correct. However, in some work situations where adequate distancing is not feasible, the correct use of protection also becomes important.
N95 masks prevent the coronavirus?
Very detailed and interesting content, this is my first video on this channel and I’ve subscribed!
Keep up the good work
What are your references for this? I've been looking for good primary sources that inform on this topic but can't find many.
Very good information. Thanks.
Could you give information about
The graphene N95 mask ??
it's literally the cotton candy process applied to molten polypro instead of sugar.
Your videos are always a pleasure watch, keep it up friend!
Why do you have a sock account?
Hey, what about the exhalation valve? Doesn't it make the mask much less useful for pathogens (if the person wearing the mask is infected)? No one seems to talk about them... I noticed that the surgical masks do not have the valves.
I’ve been talking about them for a long time. They aren’t made for viruses. They are made for places where you don’t want to breath in particles, while breathing normal. Which is why so many of these masks are pointless.
@@jamesbizs exactly...a virus is 1000x smaller than holes in masks, and when you breath out with a surgical mask, air just goes out the side. Masks do not do anything besides make you put your filthy hands that just touched 3 door knobs up to your face. Now there are dirty door knobs all over your face. Masks and the people that wear them look so dum
@@johnf817 I have to say that the person calling us dumb for wearing a mask, can't spell dumb, is frankly hilarious. Unfortunately, I can't laugh because it is so sad. Maybe try stupid instead since there isn't a silent letter in that word.
what about surgeon mask and fabric dyi one ?
Well presented
A cotton candy type process! Instead of spun sugar strands, you get spun polymer-ish strands formed and pressed into a mask shape. Kinda cool!
1:30 the dude wears the mask bands behind his helmet? Now that's odd...
thought it was wendover at first
Badass podcast
Then please explain why virologists don't rely on a n95 mask in a level 4 lab?
India produced tiny amount of N95 masks and no PPE kits in until mid march. After received faulty goods from china and returned it, they started to produce it by themselves and now India produces 5 lacks PPE kits per day and thousands of n95 masks.
But do they circulate air out?
I don't know about the type of flow of air through the mask but if we were to make it a turbulent flow, since micro vortice creation could actually help the diffusion process considerably. I believe that it will greatly further increase the efficiency of the filtration. In case if it already turbulent or unresearched yet, Here's a good topic for someone's thesis.
A mask ( or modula filters ) should only be used for eight hours max, as you will proberly get a bacteria infection from your exale moisture being filtered, as H2O droplets are large compared to viruses.
That graph at the beginning seems to be inverted?
the 8 cm are measures from the end of the blue line
it refers to the pressure difference between atmosphere and your lungs. A vacuum need more pressure difference to move the air
E0zSAtLxXSLNCsNJXZFR2zgdE hHl5UgqAbhnd7D75fr7JarwYa look at the x axis. The scale isn’t inline with the bars or what he’s saying.
@@Martin42944 dunno if i just don't get it but seems to be right, the shop-vac is at about 800cm wich is 200 less than the atmosphere at 1000
E0zSAtLxXSLNCsNJXZFR2zgdE hHl5UgqAbhnd7D75fr7JarwYa you’re right, he’s saying the difference between the bars, not their absolute value
Martin J M S he’s comparing the bars to the atmosphere pressure (blue), and not saying their absolute value, like, instead of saying that the shop vac is 800 cm of water, and the atmosphere is bout 1000 he says the difference (the same applies to te lungs bar). The reference isn’t 0, it’s 1000something (the end of the blue bar)
why explain only filtration for N95/FFP2 ? please explain also P100 (US)/ FFP3 (EU) ratings ...
P3 is the best
Lets get this man to 1M subs asap
Nice
yes these would be a good mask if you can find them to buy but i never found any yet that is made in Canada
CAN99's are made in Canada! Go get them 😊 I hear they're super protective, I believe the equivalent of an N95 Respirator
Very interesting. How about the fibers of the filter? Are they not dangerous on their own? Like the asbestos ones?
No. Not at all. These don't come off :) not like asbestos at all
It is typical the way of handling and application which compomizes the mass use of masks with higher filtration efficiencies. The problems are that these maskes where used for much more than their guarantied life time and damages and contamination due to reason that they are put on and off all the time. But, indeed, leakage is the biggest problem because nearly nobody was wearing the mask in the correct way and this is often quite difficult. Even in mask testing scenarios they have used tape, or bee wax to fix the masks to their test dummies. Otherwise they had no chance to get useful test results. But this is of course unpractical, because nobody would like to tape the mask to the face skin.
I don't wanna be that guy, but the graph comparing atmospheric and lung pressure is mislabeled?
In what sense? Seems to line up with what he's saying.
Which could also be wrong, but that's then not the graph's fault.
@@KuraIthys the lung pressure bar should be less than the vac pressure bar.
@@supriyo_biswas a shop vac can pull vacuum much lower than our lungs. I don't see where it is mislabeled?
amirunner look at the x axis compared to what he said. The label is way off compared to the value he stated the bar’s were
@@Martin42944 aaah now i see what you all are confused of. It gets confusing because of the "vacuum" term.
Vacuum means pressures lower than the atmospheric pressure.
I'll try to explain it in simple terms, and it will be long, but please bear with me:
At sea level, the air pressure around us is 1Bar, or 1019 centimeters of water (or 1019 cmH2o) . This is what we call as atmospheric pressure.
Air pressures higher that that, the air will want to blow out, like the air coming out from your tires when it punctures.
Air pressures lower than that, the air will want to go in, like your vacuum cleaner.
1. When we inhale, we are actually "sucking" the air by expanding our lungs. When we expand our lungs, the air pressure in our lungs drop lower than the atmospheric pressure, making the air want to flow into our lungs.
In the video, it says that the pressure difference between our lungs (during inhalation) and the atmosphere is 8cmH2o. What it really means is the air pressure in our lungs is lower than the atmospheric pressure by 8cmH2o.
Thus 1019 - 8 = 1011cmH2o. As displayed in the graph
2. The shop vac "pulls a vacuum of 200cmH2o". What this meant is the air pressure in the shop vac is 200cmH2o lower than the atmospheric pressure.
Thus 1019 -200 = 819cmH2o. As displayed in the graph.
3. "The shop vac is 25 times that of our lung"
This literally means the shop vac "sucks air" better by 25 times compared to our lungs
Shop vac ÷ lungs = ? times
200 ÷ 8 = 25 times. As explained in the video.
I hope my explanation is easy to understand 😂
Please correct me if i'm wrong.
So if you have an N95 mask on and you Sneeze or cough will virus particals come through? I would think so
What on earth is the person @7:30 doing?
Now I know why my dogs sniff my n95 mask like crazy
Last time I was this early, we were living in a Coronavirus free world.
We already had coronavirus before
@@eclips4638 was busy with my studies and university exam and you wont believe that this is the first time in several years, maybe 3 4, that I have had so much of free time and spending all my days watching RUclips and Piano.
Thanks so much for asking and stay safe buddy.❤
Edit: PS. What are you referring to, in the sense, you presumed that I was busy in something ? The comment I wrote is something that I saw on some other channel and I thought it was a nice thing, as I am seeing, people are really obsessed with coming first in the comment section of famous RUclips channels. Am sorry if thats a meme or something but as I said, I have not been following anything new, never had the time to follow. 😂
Again stay safe.
@@klauserji yeah.
Technically yes, everything ranging from common cold to MERS refers to Coronavirus. So, I agree to you on the fact that we have always had coronavirus around. Coronavirus is a generic term for the infamous disease Covid19. Coronavirus can be thought of as a super set and Covid19 is its subset. Anyways, stay safe buddy. ❤
@@Rajat-Sharma1 please do a little search for bob & vagena.
You've never lived in a corona virus free world. Research the scientific name for the common cold. This is misdirection. This is about social/people control. Viruses don't abide by social distancing. People do.
~boB
~boB
Please cite your sources in the video description, it would make the verification process of the informations validity far more convenient.
He has no sources, he's just another dick perpetuating hysteria for the views.
I make my own masks extra safe. I use 3M double sided tape and put it along the edge of the mask. I keep clean shaved and de oil my face area where the mask fits. At first this will take some getting used to and feels strange, since the mask naturally wants to float on the surface of the face. With the addition of tape you can add that extra step of protection for yourself. Just be sure to use a mask with fresh air inlet, and if possible an outlet also for best results.I actually submitted this idea to 3m two years ago and even have the notorized paper but don't seriously think they will listen. If they do, they will say it was their idea and claim credit. I won't protest if it helps keep everyone safe!
A thought... It’s not necessary to adhere the mask to your face. A conforming foam gasket, like window weather stripping, should work nicely.
do ffp1 masks work as just fine?
Did you even watch the video?
I use Moldex.
That conclusion was a little abrupt. Overall good video though. Thanks for the knowledge.
They don't. It must be a tight fit to the face... anyways the probability of survivable is 99.9% in the case of the 0.1% infection.
Viola. Cotton candy mask.
4:00 I kinda wanna eat my mask now..
Shame almost no one is wearing one. And the ones that are, are doing it wrong. So, yeah. They stop viruses. When you actually wear one and when you do so properly.
Also : Why there are Fake or uncertified N95 masks out there
technically, you could create such 10nm grade opening using technology photo-lithography, it wouldn't be cheap thou
Yes, but the airflow would be heavily restricted.
Is it Chernobyl bgm?
So how many nanometers is the gap around the edge of the mask circumference genius boi wonder 🤔
The thumbnail reminds me of wendover production
indeed Dr Osaoji is very legitimate, so reliable and the most honest person i'v every seen in my life time
The guy painting the guitar is wearing a chemical cartridge respirator.
dont understand it
3:30 forcing particles to navigate through high surface area maze of layered filtered media which allows air to flow while catching other particles. 5:35 some also employ electrostatic coatings that magnetize particles. 6:22 the more a filter is worn the more efficient it becomes at both trapping particles, but also restricting airflow and oxygen (aka could kill or harm you).
so basically .... cotton candy masks..
ok noted
I read that a paper pleated mask with a cloth mask worn on top of the pleated mask ( or the other way around which ever is comfortable to you ) can filter out 95 % of germs . Since I had to go the the ER a while back and they put a pleated paper mask over my cloth mask , I’m going to do that when I go anywhere . Btw , I live in North Carolina and was told the hospital near us was having to transfer new patients to other hospitals as they had so many patients. Y’all be careful and stay safe
Unfortunately that will not protect you nearly enough, especially around covid + folks 😢 please get an N95 Respirator like the ones in the video, or even better - an N99 or P100 Respirator. Some are reusable silicone! So u won't have to keep buying disposables 🙏🏼🙏🏼🙏🏼 please be very careful. Protect ur health - wear N95 or better 😊😊😊
Everybody has opinions.
They don't.
~boB
Ironically N95 masks vent exhalation bypassing the filter via the valve, the exact opposite need for trying to prevent asymptomatic spread by blocking contaminated moisture droplets in the breath.
Ironically theres no way your getting the same nanometer protection where the mask meets your face or rather does indeed have large mm gaps. And you have to be really full of covid pathogens to exhale enough through that portal etc etc etc
@@cjbrenner13 Life isn't about absolutes, it's about degree of efficacy.
No medication is 100% effective or safe. Not one. So we do that which has the most impact.
Wearing masks is the cheapest and easiest way to reduce spread by trapping infected moisture droplets from the lungs.
Why do you think surgical teams wear masks for hours on end in the OR?
@@lohphat You didnt take a moment to address the nanometers between your face and the mask. Simple redirect from the scientific process at play. Surgeons wear them as to not breathe into an open body like you dont ever find in nature lol. The body has different immune responses when its cut wide open. Ive taken dozens of medications safely as well. Youre a walking false enigma full of disinformation to make yourself sound scientific but its really not.
N95 masks are pretty fancy. Now if only they could make one that actually seals to my face
Get a normal human face.
All because of Dr wu lien teh,if it's not him i think i wouldn't survive this covid pandemic
Oh my God! A *REAL* intelligent US-AMERICAN that does not use that hilarious and anachronistic imperial system units! I am going to pray for the rest of the +330 millions left follow your plausible effort to actually fit in adequately in this modern era!
but in the reality even paint can pass in n95. miss information nowadays money vs fact.
8 hours!!! Really?
Mucus is still the primary protection we have against bacteria and viruses.
Americans: Nanometer, what is that??
Um... read the specs of N95.
3M state
N95 mask is 300n minimum
covid19 is 40n
so NO, so N95 doesn't help.
N99 or P100 might.
An easy test for a face masks effectiveness is the perfume test if you can smell perfume with the mask on then the mask is ineffective against all viruses
No because P3 filter mask would block a virus but not a smell
For some reason your thumbnail looks like a half as interesting or wendover video
Taiwanese American invented the n95 mask !! He was in retirement but is coming back out to help cause of covid19!
BS right there!
The N95 face mask is a LOT older that the first instances of Covid-19.
Yeah, that guy is pretty cool, considering the drubbing the image of 'businessman' is taking of late.
Hey - did you know that Taiwan was one of two US ALLLIED countries along with Israel, aside from Georgetown University in the US itself, who indicated that the evidence shows that the Corona virus originated in the US?
It wasn't just China and Russia who stated this. www.globalresearch.ca/covid-19-further-evidence-virus-originated-us/5706078
@@TyCetto If this is "BS", then tell it to the guy Anthony W is talking about - ruclips.net/video/EogSifN7PgI/видео.html
Ty Cetto u mad cause u thought a whiteman invented n95 mask ?? Hahahahaha u must be a racist
N98 it stops definitely but not N95. Because of the size of the virus. See documentation about fine dust filters.
They say also how people with big beard can't put the mask correctly.
Bigger beard gives better sealing of the face with the mask and the mask placement nearly to the lower eyelids gives better protection.
What would Murrays verdict be
It dosen't ,fact any air that escapes out the sides will not be filtered especially if you sneeze or cough, you need a tight seal with no facial hair, in other words you cant
I still can't breathe properly through these N95 masks
Buy a half mask with a P3 filter
Will post links if need
@@WattoPhotos need
@@zurgboy07 buy an aviva 40 and a p3 filter thats what i use.
Aviva 40
amzn.to/30q2CxF
P3 filter
amzn.to/31dKo1y
This mask good aswell
amzn.to/3iwdXTd
My blog with useful info👇
www.wattophotos.co.uk/2020/07/under-construction-my-first-day-on-blog.html?m=1
People cutting T-shirt for mask, fault sense of security
Not if they put at least 3 layers of the shirt but your right that does not protect you that good
So we are all doing this crap wrong lol
So, the guy in the hazmat suit, with a chemical protection respirator, was spraying some chemical near a children's playground. ... !?
N95 are bullshit .you need P3 or P100
And trump still refuses to put it on...
Oh shut up... The man is tested daily.
That means bandanas and homemade cloth masks do nothing... but give a false sense of security
You're right that they are not perfect, but they are not useless. Viruses like SARS-CoV-19 ride in droplets of water from your mouth. Cloth masks can easily catch those droplets and stop them from landing on people or surfaces around you. Technically your breathing could probably force some of the virus out of the masks, but it's much less likely, and would travel much less far from you even if it does.
almost as if
Cloth masks are better then nothing. But no doubt many people walking around are feeling protected better then they really are.
@@michaelmccarthy4615 The stats I saw were something around 50 to 60% reduction, so enough for some help en masse across the population, but not something to rely on individually.
@@Dr.Fluffles with the country easing up on restrictions of movement it looks like a face mask might become the last hope barrier to virus infection ...
Instead of proven good practices in place now.