First one I looked at:
As such, we estimate less than 1–2 log 10 reduction factors for normal mask wearing in public. The log reduction factor translates into less than 90% virus removal effectiveness. We assume Mred, the base aerosol reduction percentage of face masks (commercial medical products) in a public setting, to be approximately 60% [[url=https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237691#pone.0237691.ref060]60] and estimate the range from 40% to 75%, assuming the best reduction rate is 99% for a NOISH-certified N-95 type respirator [[url=https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237691#pone.0237691.ref053]53, 57, 58, 61].
https://journals.plos.org/plosone/ar...l.pone.0237691
Next one:
...immediate near universal (80%) adoption of moderately (50%) effective masks could prevent on the order of 17–45% of projected deaths over two months in New York, while decreasing the peak daily death rate by 34–58%, absent other changes in epidemic dynamics. Even very weak masks (20% effective) can still be useful if the underlying transmission rate is relatively low or decreasing: In Washington, where baseline transmission is much less intense, 80% adoption of such masks could reduce mortality by 24–65% (and peak deaths 15–69%), compared to 2–9% mortality reduction in New York (peak death reduction 9–18%). Our results suggest use of face masks by the general public is potentially of high value in curtailing community transmission and the burden of the pandemic.
https://www.sciencedirect.com/scienc...68042720300117
Here's an article written for the lay person:
https://theconversation.com/evidence...y-to-go-167963
The thing is, masks cost bugger all, and even a small reduction in infection rates has an enormous effect, especially if it takes R below 1.0
Even if you're only concerned with your own health and don't give a stuff about anybody else, masks reduce the number of infectious people around for you to meet.