I think I see what's going on in the whole mis/dis/mal-information continuum, especially in light of massive government induced censorship, often with collaboration/collusion with third parties. Mainly the inability of most to time travel, but also fear of the knowns and unknowns that you might find along the journey. Trust me, it's easy and safe. So how does one get from the top half of the below graphic to the bottom half anyway?
A couple of simple tricks of the trade.
#1) Learn how to use your search engine. Hey the Gogglie: before: 2000 air quality of operating rooms, while not foolproof, may limit search results. But words and updates of articles can skew the search results. BTW: after 2000: air quality of operating rooms should return slightly different results. Core points being - what did they know and when did they know it, limited by date. YMMV Truth be told; 2000 air quality of operating rooms seems to work reasonably well.
There is also the bang (!) parameter in some search engines. Like if you are fairly certain you saw an article on say ConspiracyTherorist.com, but you also know your search engine tends to down grade that site to page 54 of the results, you would enter Hey the Googlie: air quality of operating rooms !ConspiracyTherorist.com
#2) A proper reference library is essential. I highly recommend these time worn classics.
#3) Always dig around starting at the top and working your way down, i.e. mining 101. In other words, use some common sense and intuition, aka your gut, so the whole thing doesn't cave in on your head. That is to say, don't start or limit your looking where they tell you to look.
#4) Probably the most important and maybe should have been #1 - don't let fear of the knowns and unknowns deter you. But do keep in mind the Fear-Factor of things. People are easily and extremely motivated by fear. Sure, it could get messy. Think - fight or flight. For example:
My gut says there is no way in holy hell that surgical operating rooms rely on paper surgical masks for air quality and management of pathogens. As such my search would want to explore, based on time. EX:
before: 2009 air quality of operating rooms should turn up things like:
Notice the last couple are well after 2009. But they support the previous ones. I dunno, maybe 2009 is contained in them or they are updates. Don't matter. I just included them anyway.
This came from a similar search
before:2015 reason for surgical masks
Is Routine Use of a Face Mask Necessary in the Operating Room?
Sure as shooting, it was never paper masks. Ever!
So all the carping about we didn't know, mistakes were made, now we know - is codswallop. Always was, always will be.