What we do know on the medicine side of things is that there is really no evidence to support the use of cloth or surgical masks to prevent spread of aerosolized viral particles. There wasn’t any before COVID and there isn’t now.
Even when N95 masks are used in the hospital setting for “airborne” infectious agent exposure precautions proper fitting is required, no facial hair can be present because fit is compromised, the masks are single use and we use negative pressure airflow systems in the patient’s rooms to filter the air before it is expelled from the building. The idea that we could use N95 masks to prevent COVID spread was always folly.
No, their training is inadequate. Even in physics, studies surrounding mask dynamics are in their infancy. The data is lacking, so the science is lacking. I can't conclusively say that N95 masks don't work. They _may_ work for a time when properly fitted, which requires training. Studies would be required to be able to plot the carrying capacity curve for N95 masks with respect to viruses. (N95 masks tend to become saturated over time.)
The following article will give you some perspective on the status of the physics of mask dynamics. Note that it was published in Jan. 2022 in Nature. Groundbreaking. Super cool. Great methodology. A high quality article, unlike a lot of the articles in Physics of Fluids. And just the beginning of research in the field and very recent.
That was the case for absorbent fabrics. We don't know about the case for non-absorbent fabrics. This article concluded that absorbent fabrics increase evaporation rate a great deal. This means that the time of a droplet's existence in a mask is very short. Eventually all that is left is a residue.
We don't yet know what happens to the residue. It could be that it gets worked on by friction from air jets and the mask, which would tend to cause it to disintegrate. (That's my expectation.) Will free virus be the result of the hypothetical disintegration? Maybe. (I expect that some considerable fraction of the residue will result in free virus aerosol.)
Masks may actually _increase_ free virus aerosol. Consider that droplets >100 microns simply fall to the floor in the unmasked case. In the masked case, they are caught and possibly the viruses in the >100 micron droplets are eventually released as free virus aerosol.
So, there is a lot of physics research on masks yet to be done.
And if physics research into masks is in its infancy, then the science is unknown and public mask mandates are based on considerations other than science. Maybe hope and fear.
Or an industrial hygienist?
What we do know on the medicine side of things is that there is really no evidence to support the use of cloth or surgical masks to prevent spread of aerosolized viral particles. There wasn’t any before COVID and there isn’t now.
Even when N95 masks are used in the hospital setting for “airborne” infectious agent exposure precautions proper fitting is required, no facial hair can be present because fit is compromised, the masks are single use and we use negative pressure airflow systems in the patient’s rooms to filter the air before it is expelled from the building. The idea that we could use N95 masks to prevent COVID spread was always folly.
No, their training is inadequate. Even in physics, studies surrounding mask dynamics are in their infancy. The data is lacking, so the science is lacking. I can't conclusively say that N95 masks don't work. They _may_ work for a time when properly fitted, which requires training. Studies would be required to be able to plot the carrying capacity curve for N95 masks with respect to viruses. (N95 masks tend to become saturated over time.)
The following article will give you some perspective on the status of the physics of mask dynamics. Note that it was published in Jan. 2022 in Nature. Groundbreaking. Super cool. Great methodology. A high quality article, unlike a lot of the articles in Physics of Fluids. And just the beginning of research in the field and very recent.
"Droplet evaporation on porous fabric materials"
https://www.nature.com/articles/s41598-022-04877-w
That was the case for absorbent fabrics. We don't know about the case for non-absorbent fabrics. This article concluded that absorbent fabrics increase evaporation rate a great deal. This means that the time of a droplet's existence in a mask is very short. Eventually all that is left is a residue.
We don't yet know what happens to the residue. It could be that it gets worked on by friction from air jets and the mask, which would tend to cause it to disintegrate. (That's my expectation.) Will free virus be the result of the hypothetical disintegration? Maybe. (I expect that some considerable fraction of the residue will result in free virus aerosol.)
Masks may actually _increase_ free virus aerosol. Consider that droplets >100 microns simply fall to the floor in the unmasked case. In the masked case, they are caught and possibly the viruses in the >100 micron droplets are eventually released as free virus aerosol.
So, there is a lot of physics research on masks yet to be done.
And if physics research into masks is in its infancy, then the science is unknown and public mask mandates are based on considerations other than science. Maybe hope and fear.