4 ms·

This isn't about protection of the wearer, it's about prevention of spreading.

superkuh 6y ago
In that sense what has changed is the best guess at the main mechanisms of spread. Specifically the amount of spread mediated by large spittle on surfaces versus via aerosols. It has become increasingly clear from large spreading events (meatpacking with gloves/hygine in place, singing events being really bad) that aerosol spread is primary. So the protection that unfitted cloth masks provide, and it is some, isn't as much as you'd think against the primary mechanism of spread. Wear an unfit mask and sing and it's as bad as normal singing. I'm not arguing for not wearing bad masks when it's all you have. I'm saying it's super important that everyone starts getting real masks so we don't have to keep doing shelter-in-place every time spread goes exponential in an area again.
- ceejayoz 6y ago
  It's currently believed SARS-CoV-2 spreads primarily via droplet, not aerosol. Singing propels droplets further (as does any heavy/forceful breathing), and choirs tend to sit close together. Six feet likely isn't enough for a choir. As for meatpacking, I've heard several interviews with workers that indicated the plants were only handing out one mask per shift, and they'd pretty quickly get contaminated by gore from the work, meaning in practice folks weren't wearing masks.
  - MAGZine 6y ago
    Right. I just want to further highlight that "aerosol," in the context of medical journals, has a specific meaning, and that your lungs generally aren't capable of aerosolizing the virus into small enough matter to qualify. The spread from coughing, sneezing, etc, is still considered droplet-based spread, NOT aerosol. Droplets can still be suspended in the air for a matter of seconds, however.
    - giardini 6y ago
      MAGZine says>" your lungs generally aren't capable of aerosolizing the virus into small enough matter to qualify." No, every exhalation is aerosol and filled with particles from your body. They slip by the mask's edge and through it's seams. No mask that isn't airtight can stop those particles. Droplets are emitted when you cough or sneeze and are much larger. Droplets are like boulders, aerosol like marbles. Viruses are tiny compared with aerosols and ride on both aerosols and droplets.
  - superkuh 6y ago
    No, it was at the start. Then after a few months everyone who was reading the journal articles became aware that aerosol was the mechanism of spread and that normal human behaviors created aerosols that worked for this. The WHO and governments have lagged because they don't want people hoarding effective masks when hospitals need them more. But they can't deny reality for much longer and it's time to manufacture more instead of lying about spread mechanism. "239 Experts With 1 Big Claim: The Coronavirus Is Airborne" https://www.nytimes.com/2020/07/04/health/239-experts-with-1-big-claim-the-coronavirus-is-airborne.html https://www.nytimes.com/2020/07/04/health/239-experts-with-1... >The W.H.O. has resisted mounting evidence that viral particles floating indoors are infectious, some scientists say. The agency maintains the research is still inconclusive.

In that sense what has changed is the best guess at the main mechanisms of spread. Specifically the amount of spread mediated by large spittle on surfaces versus via aerosols. It has become increasingly clear from large spreading events (meatpacking with gloves/hygine in place, singing events being really bad) that aerosol spread is primary. So the protection that unfitted cloth masks provide, and it is some, isn't as much as you'd think against the primary mechanism of spread. Wear an unfit mask and sing and it's as bad as normal singing. I'm not arguing for not wearing bad masks when it's all you have. I'm saying it's super important that everyone starts getting real masks so we don't have to keep doing shelter-in-place every time spread goes exponential in an area again.

ceejayoz 6y ago
It's currently believed SARS-CoV-2 spreads primarily via droplet, not aerosol. Singing propels droplets further (as does any heavy/forceful breathing), and choirs tend to sit close together. Six feet likely isn't enough for a choir. As for meatpacking, I've heard several interviews with workers that indicated the plants were only handing out one mask per shift, and they'd pretty quickly get contaminated by gore from the work, meaning in practice folks weren't wearing masks.
- MAGZine 6y ago
  Right. I just want to further highlight that "aerosol," in the context of medical journals, has a specific meaning, and that your lungs generally aren't capable of aerosolizing the virus into small enough matter to qualify. The spread from coughing, sneezing, etc, is still considered droplet-based spread, NOT aerosol. Droplets can still be suspended in the air for a matter of seconds, however.
  - giardini 6y ago
    MAGZine says>" your lungs generally aren't capable of aerosolizing the virus into small enough matter to qualify." No, every exhalation is aerosol and filled with particles from your body. They slip by the mask's edge and through it's seams. No mask that isn't airtight can stop those particles. Droplets are emitted when you cough or sneeze and are much larger. Droplets are like boulders, aerosol like marbles. Viruses are tiny compared with aerosols and ride on both aerosols and droplets.
- superkuh 6y ago
  No, it was at the start. Then after a few months everyone who was reading the journal articles became aware that aerosol was the mechanism of spread and that normal human behaviors created aerosols that worked for this. The WHO and governments have lagged because they don't want people hoarding effective masks when hospitals need them more. But they can't deny reality for much longer and it's time to manufacture more instead of lying about spread mechanism. "239 Experts With 1 Big Claim: The Coronavirus Is Airborne" https://www.nytimes.com/2020/07/04/health/239-experts-with-1-big-claim-the-coronavirus-is-airborne.html https://www.nytimes.com/2020/07/04/health/239-experts-with-1... >The W.H.O. has resisted mounting evidence that viral particles floating indoors are infectious, some scientists say. The agency maintains the research is still inconclusive.