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-   -   It's just the flu! (https://www.airlinepilotforums.com/covid19/129019-its-just-flu.html)

Purpleanga 06-21-2020 04:40 PM


Originally Posted by Duffman (Post 3078809)
Thank you for providing references.

https://www.livescience.com/are-face...us-spread.html
This article references a single study done in S. Korea using only 4 participants "The other [study] looked particularly at SARS-CoV-2 and found no effect of either surgical or fabric masks on reducing virus spread, but only had four participants and ... The researchers didn't look at distances beyond 7.8 inches to see if droplets didn't travel as far while people were wearing masks, Chu said."

https://www.theguardian.com/world/20...ct-on-covid-19
Everything here is replying to this particular report:
https://rs-delve.github.io/reports/2...al-public.html
The scientists' issues seem to be with the methodology of that report in particular and lack of evidence. They don't address any of the studies that show masks favorably.

https://bgr.com/2020/04/13/coronavir...rgical-how-to/
This article pits this study, which shows that cloth masks are very effective against other coronaviruses:
https://bgr.com/2020/04/13/coronavir...rgical-how-to/
Against the aforementioned study in S. Korea where 4 participants coughed on petri dishes 7.8" away.

https://www.cidrap.umn.edu/news-pers...sed-sound-data
This provided the most compelling data against masks, but it also seemed strongly biased. In the last paragraph it becomes evident why (at least to me):

"Ways to best protect health workers

We recommend that healthcare organizations follow US Centers for Disease Control and Prevention (CDC) guidance by moving first through conventional, then contingency, and finally crisis scenarios to optimize the supply of respirators. We recommend using the CDC's burn rate calculator to help identify areas to reduce N95 consumption and working down the CDC checklist for a strategic approach to extend N95 supply.

For readers who are disappointed in our recommendations to stop making cloth masks for themselves or healthcare workers, we recommend instead pitching in to locate N95 FFRs and other types of respirators for healthcare organizations. Encourage your local or state government to organize and reach out to industries to locate respirators not currently being used in the non-healthcare sector and coordinate donation efforts to frontline health workers.
Really buried in the article:
"There is some evidence that surgical masks can be effective at reducing overall particle emission from patients who have multidrug-resistant tuberculosis,
36 cystic fibrosis,34 and influenza.33 The latter found surgical masks decreased emission of large particles (larger than 5 µm) by 25-fold and small particles by threefold from flu-infected patients.33 Sung37 found a 43% reduction in respiratory viral infections in stem-cell patients when everyone, including patients, visitors, and healthcare workers, wore surgical masks."

The citations at the bottom also provide some interesting reading. Basically, cloth masks and surgical masks are worthless at screening air coming in and going out, but we already knew that. The reason they're effective is because they limit the distance the virus travels from normal talking to about a foot (vs 6' without a mask). With a virus that has such a long incubation period, that's a very good thing in the general public.


https://www.webmd.com/lung/news/2020...virus-strategy
This article quotes several studies showing that masks help significantly. The only study quoted that casts doubt is, once again, the same S. Korean study with 4 people coughing on a petri dish at 7.8'

https://www.bmj.com/content/369/bmj.m1422
The article largely quotes older studies that display cloth and surgical masks do not effectively filter particles as small as viruses. This is not contested and widely known. The reason masks are supposed to be effective is because they reduce the distance of the aerosol plume. That could mean the difference between getting the virus from talking with someone whose infected and not.

Also from the same article:
"But Ian Jones, professor of virology at the University of Reading, said, “If an aerosol droplet hits the weave of the mask fabric rather than the hole it is clearly arrested. And lessening the aerosol dose chips away at the R0 [reproduction number] and helps to slow the epidemic . . . They are not a cure but they address the longer flatter epidemic curve everyone is trying to achieve.”

Once again, it seems the question is "would you prefer a cloth mask or a surgical mask?" Obviously a surgical mask. The scientists don't address any of the studies that speak favorably to masks (although it was published 7 Apr) and most of their supporting references show that the masks themselves don't filter out everything, which once again, we already knew.


This isn't enough to convince me masks are useless and all the studies favoring them are garbage. It's well known N95>surgical>cloth. Masks are supposed to limit the distance of the plume of infected aerosols, especially with asymptomatic people. Also, social distancing is a huge problem on airplanes and we need anything that can help mitigate that, especially when we're sitting at the gate fully loaded with the engines off and just PCA. The CDC and WHO said non N95 masks didn't work at the onset for a reason; that was the accepted belief by the entire medical community. But after COVID19 people started taking a good look at masks because we really don't have many other options (Home Depot won't have N95s for a looonnngg time). And yes, scientists change their minds frequently, but usually when presented with new, conflicting data. I've changed my mind on this once before and I might do it again if there's enough compelling data.



Nobody knew anything about this virus. And we’re still learning things. So I don’t care if the CDC changed their tune on wearing masks. I follow what the health community tells me. Mostly because I don’t have an agenda. Also, masks only work if the other person is wearing one too. I think someone else said it, we follow what they tell us and the quicker we’ll get through this.

contrails12 06-21-2020 04:59 PM


Originally Posted by Purpleanga (Post 3078823)
Nobody knew anything about this virus. And we’re still learning things. So I don’t care if the CDC changed their tune on wearing masks. I follow what the health community tells me. Mostly because I don’t have an agenda. Also, masks only work if the other person is wearing one too. I think someone else said it, we follow what they tell us and the quicker we’ll get through this.

1000%

going forward we’ll have to look at creating a leadership position in the government that has a platform large enough and powerful enough to be able to coordinate a singular message for all of the American people regardless of political affiliation. Like a president or something

GeeWizDriver 06-21-2020 06:43 PM


Originally Posted by Purpleanga (Post 3078823)
Nobody knew anything about this virus. And we’re still learning things. So I don’t care if the CDC changed their tune on wearing masks. I follow what the health community tells me. Mostly because I don’t have an agenda. Also, masks only work if the other person is wearing one too PROPERLY. I think someone else said it, we follow what they tell us and the quicker we’ll get through this.

Fixed it for you.

Some of you rail against people who are dubious about the effectiveness of masks but say nothing about the very high percentage of our countrymen who wear them improperly. I call them "chin warmers."

Susie Soccermom wearing her home made, cloth, fashion forward facecovering down over her chin with her nose sticking out is doing only one thing about the virus: virtue signaling.

AZFlyer 06-21-2020 07:02 PM


Originally Posted by GeeWizDriver (Post 3078879)
Fixed it for you.

Some of you rail against people who are dubious about the effectiveness of masks but say nothing about the very high percentage of our countrymen who wear them improperly. I call them "chin warmers."

Susie Soccermom wearing her home made, cloth, fashion forward facecovering down over her chin with her nose sticking out is doing only one thing about the virus: virtue signaling.

Alyssa Milano:
https://external-content.duckduckgo....jpg&f=1&nofb=1

rickair7777 06-21-2020 07:18 PM


Originally Posted by AZFlyer (Post 3078887)

Macrame. Latest thing in N95/HEPA.

contrails12 06-21-2020 07:57 PM

Alyssa Milano in a homemade mask!!! OMG WTF HEHEHEHAHAHA WHOAZZA

what a Helen Nancy Karen lolz. Libtard cuck beta soy!
what? She’s promoting masks during a pandemic?

she should know better. The only way to save America is to stretch Putin’s sack across your face.






ps. Yeah I know a yarn mask or whatever it is is probably the worst option for a face covering. But it’s better than nothing, which is what many here think is necessary.

Hawaii808 06-21-2020 08:30 PM


Originally Posted by AZFlyer (Post 3078887)

it turns out her mask is made by her mother and actually has a filter pouch. Ironically, her mask is probably better than most cloth masks.

badflaps 06-22-2020 03:27 AM


Originally Posted by Hawaii808 (Post 3078913)
it turns out her mask is made by her mother and actually has a filter pouch. Ironically, her mask is probably better than most cloth masks.

I think her mom should lay off the sherry, I see a couple of dropped stitches.

Duffman 06-22-2020 04:53 AM


Originally Posted by Purpleanga (Post 3078823)
Nobody knew anything about this virus. And we’re still learning things. So I don’t care if the CDC changed their tune on wearing masks. I follow what the health community tells me. Mostly because I don’t have an agenda. Also, masks only work if the other person is wearing one too. I think someone else said it, we follow what they tell us and the quicker we’ll get through this.

Very true, but following what they (CDC, WHO, and medical community) tell us is a moving target that's often at odds with each other. Neither organization is wrong regarding the current data, they're just looking at different evidence trying to fill in the gaps. After seeing all the TP fly off the shelves I don't blame them for trying to discourage hoarders from buying out lifetime supplies of N95s so they can improperly wear them to the super market once a month while frontline health workers have been using the same expired respirator for months now, but when you know there's an underlying agenda, no matter how noble, it does affect the credibility.

Every mask study done before COVID19 basically showed stopping viruses with a cloth mask was like trying to stop mosquitoes with an electric chain link fence, which is true. But follow-on research, most of which has been done after COVID19, suggests that the real benefit of masks has more to do with how it affects the fluid dynamics of air leaving an infected person's mask, which shortens the distance virus particles are sprayed. Most likely for the same reason the air filter on your car reduces the airflow into your engine (despite being designed for the opposite).

The more complicated fluid dynamics of "small particles" which are roughly virus-size (0.1 micron) cause them to behave erratically in the air, making them more likely to be trapped by a mask. Particles that are 0.3 micron are actually the most difficult to trap because any smaller, they exhibit the erratic movement and any larger, obvious reason. That's why 0.3 micron is the metric for N95 masks. I did manage to get an A in fluid dynamics, although it was for civil engineering.

Before all this I thought if you breathed in a virus you were infected and you were either infected or not, so the amount of virus didn't matter. Research from COVID19 has indicated the opposite, which adds to the case that masks do help:
https://www.statnews.com/2020/04/14/...make-you-sick/

Duffman 06-22-2020 05:14 AM

Further update, this was posted by Johns Hopkins on 3 Jun:
https://www.hopkinsguides.com/hopkin...9__SARS_CoV_2_

It indicates the virus largely spreads by fomites and droplets, not aerosols. The difference between droplets and aerosols is basically size. Aerosols are extremely hard to trap and would mean the virus could readily spread through HVAC systems, aircraft, air currents, etc. Droplets are much larger, basically "say it don't spray it." I should point out that droplets can still be very very small and can linger in the air for an hour or so after they've been released (the smaller the droplet the slower the terminal velocity).

As long as someone's mouth is covered when they talk, cough, or sneeze, even a cloth mask could trap droplets. Furthermore, this reduces the amount of fomites they leave behind, which are viruses that are released in a droplet, fall on a surface and live there until you touch them, touch your face, and infect yourself. This could explain why even cloth masks are shown to be more effective with COVID19 than other viruses.

I wouldn't take the "key takeaway actions" from any study or report as gold right now, because it could be completely altered tomorrow when another study brings more game-changing data, but it does help bring the overall picture into better focus and highlights the importance of at least covering your mouth with a mask, proper hand washing, and not touching your face. Furthermore, if this is true, it means aircraft are a safe way to travel as long as people don't have long conversations with each other without masks. It wouldn't surprise me if, in the near future, airlines add into their standard PAs that unnecessary conversation should be avoided.


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