4 ms·

This study was posted earlier this week to HN: https://advances.sciencemag.org/content/early/2020/08/07/sciadv.abd3083 https://advances.sciencemag.org/content/e

by DeRock 6y ago

This study was posted earlier this week to HN: https://advances.sciencemag.org/content/early/2020/08/07/sciadv.abd3083 https://advances.sciencemag.org/content/early/2020/08/07/sci... If you look at the figures, you see that valved N95 masks still outperform many other non-valved options for filtering expelled droplets. I wonder if there is any study backing AAs decision, or is it based solely on public perception? In general, I'm surprised about the lack of information and evangelization about effectiveness of different types of masks. Non-valved N95 are vastly superior to all other low cost / disposable masks, yet they are difficult to find. I've heard reports that the supply chains are being directed predominately towards medical use, but I'm curious what's limiting the production side to making these viable for everyone.

arcturus17 6y ago
> Non-valved N95 are vastly superior to all other low cost / disposable masks, yet they are difficult to find In the study you link, surgical masks come in second, extremely close to non-valved N95, at nearly 0 relative droplet count. Are surgical masks not considered disposable and low cost, or are they hard to find in the US? Where I live, they are price-capped by the government and available everywhere from pharmacies to grocery stores.
- DeRock 6y ago
  If you look at the supplemental figure S1 here: https://advances.sciencemag.org/content/suppl/2020/08/07/sciadv.abd3083.DC1/abd3083_SM.pdf https://advances.sciencemag.org/content/suppl/2020/08/07/sci... You'll see that the N95 exhibit an order of magnitude greater reduction than surgical (99.9% vs 99% reduction against no mask baseline). Whether this practically matters, I don't know. If surgical masks are much cheaper/easier to manufacture, then I concede that those should be the focus. However, my point still half stands. Most cotton masks perform poorly. If AA was basing this policy on empirical effectiveness, they would ban those before valved N95.
bassman9000 6y ago
Let's be practical: N95s are more expensive, and terribly uncomfortable for long periods of time, like the ones experienced in flights. Given how close to N95s the next options are, in terms of droplet transmission, will anyone realistically choose full N95s?

by DeRock 6y ago

arcturus17 6y ago

> Non-valved N95 are vastly superior to all other low cost / disposable masks, yet they are difficult to find In the study you link, surgical masks come in second, extremely close to non-valved N95, at nearly 0 relative droplet count. Are surgical masks not considered disposable and low cost, or are they hard to find in the US? Where I live, they are price-capped by the government and available everywhere from pharmacies to grocery stores.

DeRock 6y ago
If you look at the supplemental figure S1 here: https://advances.sciencemag.org/content/suppl/2020/08/07/sciadv.abd3083.DC1/abd3083_SM.pdf https://advances.sciencemag.org/content/suppl/2020/08/07/sci... You'll see that the N95 exhibit an order of magnitude greater reduction than surgical (99.9% vs 99% reduction against no mask baseline). Whether this practically matters, I don't know. If surgical masks are much cheaper/easier to manufacture, then I concede that those should be the focus. However, my point still half stands. Most cotton masks perform poorly. If AA was basing this policy on empirical effectiveness, they would ban those before valved N95.

bassman9000 6y ago

Let's be practical: N95s are more expensive, and terribly uncomfortable for long periods of time, like the ones experienced in flights. Given how close to N95s the next options are, in terms of droplet transmission, will anyone realistically choose full N95s?