How do masks not help curb the spread of a virus? Do you have any supporting literature on that matter?
As you know, virus particles are too small to be stopped by the openings in the mask (which allow you to breathe). They are airborne, like smoke.
N95 masks have an electret layer which is made by blow molding fiber against a charged target. The result is charge embedded in the fibers. The charged fibers attract and hold the virus particles.
It would be possible to add an electret layer to a surgical mask, but it seems that this isn’t generally done, probably because they fit so poorly. Maybe someone here could speak to that.
Look at N95 on Wikipedia. The EU has required N95 on transportation for some time.
The Bangladeshi study mentioned in this thread might have used something like that (it isn’t clear from the paper and the promised paper on what kind of surgical mask they used hasn’t appeared yet).
Bottom line: the masks commonly used in the US over the past two years do virtually nothing, unless someone is coughing. How many coughing people have you seen in panic lately?
We found clear evidence that surgical masks are effective in reducing symptomatic seroprevalence of SARS-CoV-2. Although cloth masks clearly reduce symptoms, we find less clear evidence of their impact on symptomatic SARS-CoV-2 infections, with the statistical significance depending on whether we impute missing values for nonconsenting adults.
I don't believe we have any good studies out of the US or Europe. There's a discussion about this and more on the Econ Talk podcast this week: https://www.econtalk.org/vinay-prasad-on-the-pandemic/