You also still don't seem to understand that reducing aerosols in the air rather than preventing them from being breathed in is the value in having everyone "mask up"
The mask thing is pretty easy- here's one study-
https://pubs.acs.org/doi/10.1021/acs...3252?ref=pdf&# from Chicago that studies the effectiveness of various materials and combinations of materials in a study using flow and particle size of normal breathing.
The study separates the particle size data in >300nm and <300nm. The larger category nicely represents the size of aerosol that one breathes out, the smaller the aerosol that one breathes in, and while not quite understood, currently, the average COVID19 size in ~150nm.
So the study shows the effectiveness of blocking stuff as you breathe OUT and IN in the same study- and it clearly shows that masks can significantly reduce the amount of particles in both sets of sizes. One should note- they do clearly show that fit and leakage is very, very important. But it's interesting that there's clear data that shows a person how they can make a mask that is more effective than an N95 mask
Another study actually shows that the masks appear to be more effective than distancing- as even with the distancing issues that workers had in New York (having to use common travel methods), once masks were required, the drop in cases was dramatic. I posted that study before.
The great irony for people who want to force things to open- if you REALLY want to do that, requiring masks is a very economical way of doing it, as it will reduce the spread dramatically- both allowing businesses to be open and reducing the strain on the healthcare system.
I'm sure there are a lot more studies out there now- with different materials, and different combinations. And one should note that this isn't about making someone money selling masks, as many of these studies are about DIY masks, using materials you may have spare around the house. Or that is cheap at the store.
Unless there's a clear study that has real data that shows otherwise, and the method of testing is clear and representative of real breathing- the data of the effectiveness stands.
Here's what gets many of the right- early in the outbreak, we were told to not wear masks and that it only helps if you are sick. Since then, real data has been generated (multiple times) which has advanced the state of knowledge greatly. But they can't move on from the original statement. I've heard that exact line from real scientists, oddly enough. Once that actually tested the effectiveness of respirators. Instead of adding to the body of knowledge over cloth masks, they just regurgitated the line original line. For them, all that did was make me doubt their opinion- since I would have expected a scientist to WANT to add to the body of knowledge and state of the art instead of not.
