"In unpublished work, Linsey Marr, an environmental engineer at Virginia Tech in Blacksburg, and her colleagues found that even a cotton T-shirt can block half of inhaled aerosols and almost 80% of exhaled aerosols measuring 2 µm across. Once you get to aerosols of 4–5 µm, almost any fabric can block more than 80% in both directions, she says."
"Benn worked with Danish engineers at her university to test their two-layered cloth mask design using the same criteria as for medical-grade ventilators. They found that their mask blocked only 11–19% of aerosols down to the 0.3 µm mark, according to Benn. But because most transmission is probably occurring through particles of at least 1 µm, according to Marr and Jimenez, the actual difference in effectiveness between N95 and other masks might not be huge."
https://advances.sciencemag.org/content/6/36/eabd3083
> A bigger droplet scatters more light than a smaller droplet. This insight is important to interpret the result of the neck gaiter. The neck gaiter has a larger transmission (110%; see Fig. 3A) than the control trial. We attribute this increase to the neck gaiter dispersing larger droplets into several smaller droplets, therefore increasing the droplet count. The histogram of the binary diameter for the neck gaiter supports this theory (see fig. S5).
The only mask that was worse than nothing was the Neck Gaiter, but the difference was both clinically small as well as statistically insignificant.
- Available
- Cheap
- Plentiful
- Comfortable
Without a conversation, it's impossible to get people to wear them.
As a footnote, COVID19 spreads through both large droplets and aerosol, and infection is highly dependent on initial viral load. Eliminating large droplets is helpful, especially on the way out.
This doesn't matter to Paul. Him, and most of his colleagues/voters, etc. base their ideals on individualism. To them, pro-social behavior, like wearing a mask to protect others, is inconceivable.
... and ironically, the liberals are far more individualistic, and conservatives, collectivist, at least as anthropologists use the term.
A big part of the rationale for limited government is family and church support support networks.
But take a step above all of this for a second. Let's say your mask reduces the speed of the spread. Say you wear an N95, and you reduce your chances of getting it in any one day, to near 0. Well that will work...until you take it off. One day, you will have to take it off. And the virus will be right there waiting for you.
Masks may "work" in terms of slowing things, but they don't work in terms of increasing your lifespan more than a few minutes on average, or ending the pandemic. Vaccines do that, or lots of people surviving an infection.
Remember that for all that time in Nov-Jan last winter in the West, everybody and his dog was wearing a mask. Yet more people than ever got it anyway.
I thought the reason we should all wear masks is to protect everyone else around us by preventing our breathing/speaking from creating clouds of airbourne droplets.
I.E. it is supposed to filter the air you put out more than the air you breathe in.
If you insist on 100% protection then n95 masks don’t “work” and neither do vaccines but that’s misleading as a public heath campaign.
This is the only part of your comment I disagree with. “Science” has very little sway in cultural debates with either side.
Instead, they try to present absolute certainty that you have to do this in order to try to persuade those who aren't really listening and don't believe you. But those who aren't really listening and don't believe you are that way partly because they detect that you're talking way past your evidence.
("You" meaning politicians, not the parent, nor the reader.)
There are good and bad masks, just as there is good and bad food.
A cloth mask will not protect you against an aerosol (note: am a researcher who has seen the electron microscopy images proving this), that is why N95s are mandated with no beards in any ISO work environment where you are subjected to aerosol risk.
The inability of public dialog on this nuance is just a reflection of our poor scientific education.