Welcome back to yet another coronavirus covid 19 article, it's becoming clearer and clearer now that this coronavirus spreads not just through contact and respiratory droplets that fly through the air like ballistics, but also it's being transmitted through the airborne route meaning through aerosol. So meaning the virus lingers in the air and then someone comes and inhales that virus into their lungs.
Let's face it there is a reason why hospitals with designated covid areas require everyone to wear a n95 respirator mask as well as eye goggles that's because we know that this virus has the potential for airborne transmission previously. The who said that this virus only spreads through contact and respiratory droplets and doesn't spread by the airborne route unless it was related to aerosol generating procedures like with an intubation or bronchoscopy.
When someone is using a cpap mask or a bypass mask it actually wasn't until july 9th that they formally recognized that it could be transmitted indoors by means of aerosol or at least they said that they can't rule out this possibility. They finally admitted this after hundreds of experts had called on them to do so and look it's not like the who hasn't made blunders before on february 25th.
This is a pandemic and explaining why that is but for today's article I want to start out by saying yes, unfortunately covid 19 is now a pandemic even though it's not official. But it wasn't officially declared a pandemic by the who until march 11th, I don't know why it took them so long. Then there was the whole blunder of them saying there isn't a symptomatic spread, which we already known that it does spread a symptomatically for like two months at that point.
Then the next day they actually self-corrected so why until recently have they not acknowledged airborne transmission, two main reasons one because there is still no definitive evidence. That proves airborne transmission, of course it's always nice to be sure about something before making a public statement. But sometimes you have to take action and implement safety precautions without having definitive proof.
The second main reason is that declaring airborne transmission has big implications, you already see how bad things are with masks and social distancing in the debate over reopening schools and such well if this virus spreads by the aerosol route. Before I get into that let's actually start out by defining what airborne transmission really is because most people don't actually know what it really means. Let's rewind to february 11th explaining airborne transmission then there's airborne precautions.
Some lung infections and some throat infections spread when small viral or bacterial particles stay suspended in the air and can be inhaled by other people. The 2019 novel coronavirus is believed to fall into this category, this category also includes other viruses like the sars virus, measles, chickenpox and tuberculosis which is actually a bacteria and then this study came about march 18th.
There's now a new non-peer-reviewed study that just came out by nih that shows the virus remains in aerosol meaning in the air for up to three hours, now at this point we don't know how much of a viral load in that aerosol. You need to inhale in order to come down with the infection so that is still an unknown at this point so just because it remains aerosolized for up to three hours that does not necessarily prove that it's an airborne transmission. But I would think that's the case more studies are needed to prove this one way or another but let's get more into the nitty-gritty of aerosol transmission.
During normal breathing and speech tiny particles are emitted mainly from the mouth these particles can range in size with the smallest being less than a micron and the biggest being over 500 microns in diameter. Now to put some perspective on that the average diameter of a human hair is about 80 microns, typically droplets that are less than 5 microns are considered small and it's these small droplets that can be suspended in the air droplets that are over 100 microns are considered large and droplets that are between 5 and 100 microns are intermediate.
But the reality is it's a range of sizes it's a continuum it's a spectrum from less than 1 micron to over 500 microns and more and more particles are emitted when someone is breathing heavier such as with exercise or if someone is coughing or sneezing or if someone is shouting or singing. Due to gravitational forces particles that are bigger than five microns tend to settle meaning fall down on surfaces such as the floor and they fall fairly close to the source typically within six feet. This is why the cdc recommends six feet for social distancing. But here's the thing sometimes these larger particles travel farther than that especially if someone is breathing heavy or shouting or singing or coughing or sneezing typically they fly no further than 12 feet in these situations. But we're also spraying particles that are smaller than 5 microns and this is why these tiny particles they don't act like ballistics they act more like a gas cloud, where they float in the air and travel up to 27 feet.
The ones that are less than one micron evaporate within milliseconds of hitting the air, while the particles that are more than 100 microns can take up to a minute to evaporate. So what happens when the droplets that are less than five microns what if they're spewed from someone who's infected with the virus and all of a sudden in midair, they evaporate well. They dry out and you're left with a virus that is floating in the air these are called droplet nuclei aka aerosols. There are lots of factors that determine how long aerosols remain in the air just like there are a lot of factors that determine how long a fart will stink up a room. It depends on the person who emitted the particles, how they emitted them the temperature and humidity of the environment.
Now let's take a look at what happens when someone sneezes, this was published in the jama article and they took a super slow motion video of a healthy person sneezing. You can see the varying degrees of droplet, sizes the larger ones fall to the floor like ballistics. But the tiny ones remain airborne in this wet cloud, if you will not only does this wet cloud help keep the virus viable for a longer duration. But this cloud can travel about 23 to 27 feet depending on the conditions lack of airflow, means that this cloud will persist longer and when this moist cloud finally does dissipate you're still going to have droplet nuclei that stay airborne for about three hours.
Based on that nih study a lot depends on the airflow of that environment this is the reason why scientists in china actually found the cyrus coronavirus, ii viral particles in the ventilation systems of hospitals that had covid patients in it. Now proving that airborne transmission exists is actually harder than one may think the best way to prove it from a scientific standpoint would be to line up a bunch of people in a room, who have covid. Then you line up a bunch of other people who don't have covid keep them 20 feet apart from each other and then let them stay there for several hours and see who gets covid, obviously from an ethical standpoint.
This is what we call but what we can do is look back at real life situations that sort of mimic this scenario like. For example what happened in this chinese restaurant in this study, they reviewed video footage after they realized that three different parties ended up being positive for coronavirus. What they realized was that there was no evidence of direct or indirect contact between the three parties who ended up getting the virus, their results effectively showed that the infection distribution was consistent with airborne transmission.
They even recreated this scenario using a warm tracer gas and computers to simulate the spread of exhaled droplets from the index person meaning the person who is spreading it to other people and when they did the simulation, they were able to recreate that scenario. Then there was this in a semi-rural area in the state of washington 60 singers convened for choir practice mind, you this area of washington was not a hot spot. They didn't have any known cases at the time in this area all the singles were feeling fine, they were in good health that day and supposedly no one was known to be coughing or sneezing. Hand sanitizers were provided they took measures to socially distance presumably six feet and they avoided hugs and handshakes and proceeded to belt out the high notes.
Now on to the sad part within three weeks of this event 45 out of the 60 were diagnosed with covid and two ended up dying so what was the conclusion, it was that most likely this spread was due to aerosolization. Recently three passengers on a delta flight came down with the virus although we don't know the details and this doesn't necessarily prove or disprove airborne transmission. So at this point we might not have 100 conclusive evidence that proves airborne transmission but there are now several studies that strongly suggest that to be the case.
It's just like in a murder trial if you have enough circumstantial evidence you can still paint enough of a picture to get a conviction without necessarily having a bloody fingerprint. Now just because we know that this virus spreads through the airborne route that's not to say it doesn't spread through contact and respiratory droplets meaning bigger droplets that act like ballistics it spreads by all three of these mechanisms, so hand washing is still important as is not touching your face or mask with dirty hands and maintaining six feet apart is a good thing.
But it's not good enough for certain situations remember earlier how I said when someone sneezes that moist cloud containing aerosols can travel up to 27 feet and the virus can linger in the air for three hours. What good is six feet going to do you in that situation, it's better than no distancing but it's not good enough. Now some rooms have adequate ventilation that supply clean outdoor air and minimizes recirculated air, the better the ventilation the less likely. The spread of aerosols and even cracking open a window can make a huge difference and having a fan blowing is a good thing too and generally speaking opening doors is a good thing open it.
Other measures can help too like having an air purifier with high efficiency air filtration and germicidal uv lights. By the way if you're looking to buy an air purifier I recommend to go get one that has a filter, that can filter out particles of less than 0.5 microns. Which is one that I,m actually about to get it's called levot or levo I don't know how to pronounce that but anyway. It's an air purifier and this bad boy can fish out particles as small as 0.3 microns.
When you're outdoors or indoors with good ventilation the virus is much less likely to spread via the aerosol route especially if you're at a minimum six feet apart and there isn't overcrowding and especially if everyone's wearing a mask. Now let's talk more about masks I want to show you this very impressive study that was published june 30th, now in this study they set up a dummy and created simulations of coughing first without masks and then with different types of masks or face coverings. if you will they use tracers to visualize the cough in the cloud that forms as a result of the cough it showed that the cough expelled the gas up to 12 feet in a span of 50 seconds.
After that they covered the dummy's face with different types of face coverings so without a face covering the average jet distance was eight feet and the maximum was twelve feet with a bandana made out of elastic t-shirt material. The average distance went down to about three and a half feet with a folded handkerchief that was made out of cotton. It was about one foot three inches and with a stitched mask that was made out of quilted cotton, it was about two and a half inches and with a commercial mask specifically a cvs cone face mask it was eight inches and with this medical mask or surgical mask you could assume it's going to be about 8 inches.
Now mind you in this study the tests assume that the mask is properly worn and not saturated with water or sweat which can affect the distance of the jet propulsion. These types of masks are good at helping to mitigate the spread of the virus to other people are they perfect at doing so absolutely not but they do make a big difference. What they don't do is prevent you from inhaling the virus because where there's openings that's where the air gets sucked in and that's where you can inhale it but if you have an n95 respirator mask or an elastomeric respirator then your chances of inhaling that virus go down dramatically.
At 95 respirators are tight fitting and filter out at least 95 of airborne particles as small as 0.3 microns and elastomeric respirator is a reusable device with exchangeable cartridge filters. Like an n95 respirator it also filters out at least 95 percent of airborne particles as small as 0.3 microns, it fits tight against the user's face but it is more comfortable than an n95. Before reusing the mask all of its surfaces do have to be wiped down with a disinfectant so although both of these are not perfect. They are very effective at preventing inhalation of the virus but there are a couple of issues with the n95 for one they're hard to come by because they're being reserved for healthcare workers and actually amazon won't even sell them right now.
They're also uncomfortable and as you could probably tell your voice gets muffled and they can sort of hinder your breathing or make you feel smothered also. They have to be properly fit on your face and in order to do so that means you can't have facial hair in this region. The cdc actually has a diagram of what facial hair styles are compatible with the proper mask fit, I recommend not going with the toothbrush in case you're wondering i'm not even allowed to have this. When I go back to work I got to shave all this in order for me to have a properly fit at 95.
But wearing one of these n95 masks for long is not practical for most situations for the reasons, I just mentioned with that said I do wish that there wasn't a limited supply because lots of people would benefit from wearing one in certain situations. Like for example whenever people are in an enclosed space like elevators small rooms and airplanes and I do want to talk about flying on an airplane because there's actually a lot to say about that. There are pros and cons to both flying versus driving when it comes to preventing getting covered. I'm dedicating a whole article to that so don't forget to subscribe and hit that bell notification, if you haven't done.
Getting back to elastomeric respirators should you buy one of these, I would say it depends if you're worried about getting the virus especially if you're in situations that have a high risk of airborne transmission then I'd say yeah. If you have to fly in an airplane which I might actually be flying pretty soon. But what I plan on doing is wearing my n95 mask along with my motorcycle glasses and with the n95, the chances of me inhaling the virus are pretty slim. If you don't have an n95 then the elastomeric respirator might be an option for you. If I were to buy one I'd probably go with this one the 3m 7503 large silicone ultimate 7500 series as it gets great reviews and I'll just like bane you can minimize your chances of inhaling the virus and other viruses as well powerful agents to the united states.
We are initiated and if you want decent looking goggles or glasses to prevent the virus from getting into your eyes, you can get these they have you covered in the front and the sides too. They also come in the form of sunglasses and they're pretty cheap on amazon, so let's summarize if you really want to maximize your protection from this virus. There are things that you can do and I'm not saying all these things are practical, I'm just saying that this is what you can do for maximum protection.
The first thing avoid people not always possible but the further away the better six feet is better than nothing but still not great 12 feet means you're not going to get any of those droplets spread into your mouth and nose in that ballistic form but 12 feet is still not enough to prevent airborne transmission. So for that you really need 27 feet or so and that's going to depend on various factors all right. The second thing is if you're unable to avoid people and in a situation where airborne transmission is possible wear protective eyewear in either n95 or elastomeric respirator.
The third thing is if you're around people better to be outdoors, if you're indoors or around others try to open doors windows consider having a fan for better circulation hopefully there's good ventilation in that room and you can also consider getting an air purifier with hepa filter for that room. The fourth and final thing is if you don't have a respirator mask, a surgical mask or a medical mask mainly helps to prevent you from spreading that virus to someone else.
However it does offer some protection from respiratory ballistics being sprayed into your mouth and nostrils but this won't prevent you from inhaling the virus, if it's in the air around you it's windows not working no I locked them. So we could get a good clambake going on in here, so i'm going to wrap this one up. If you like my article please follow for more contents like this, thanks for reading.
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