I got a link to this very interesting article from a financial newsletter I get.The fellow is very good on the markets but is totally against lockdowns so finds some interesting bits of reading..This is an article by a fellow called Brett Sutton 20 years ago when he was a junior doctor at the NWRH,Tasmania on the subject of whether anaethetists should wear masks in theatres.In fact it made no difference to infection rates.
PDF | Many operating theatre staff believe that the surgical face mask protects the healthcare worker from potentially hazardous biological infections.... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
The studies they quoted did not give the results you would have thought.
View attachment 256232
Now this is a study on bacterial infections not viral.So not directly relevant to now.