That's wrong. With or without a mask, if you are in the same, non-ventilated room, chance of your contracting virus is the same and you need to be there for 3h+.
I think that's probably true if there's poor airflow, and I'm not convinced by the notion 'open you window for a few minutes once in a while to stop the spread.' Without a clear airflow of old air out, fresh air in, particles are going to linger, and I'd even consider that conflicting air currents from fresh air + wind outside + differences in temperature would result in microscopic droplets staying airborne longer than in still air in a passive setting like a living room.
However, mask wearing in shorter periods like a visit to the shops will reduce viral presence in the air from any infected because of the interrupted airflow. It's not even about having holes smaller than the droplets, but turbulences caused from the interrupted airflow plus static attraction to fibres etc. It's the difference between a water gun shooting a laminar flow or just turbulent water.
As for real science showing one way or another, I doubt there's much meaningful out there (if there is, I'm sure Mariner will have it!). I've seen a whole bunch of poorly considered experiments but mostly it's data analysis in scenarios with many variables at play - "we see a clear 30% r4eduction i virus spread where masks are worn; oh by the way they also were social distancing and working from home and not going so much and limiting group sizes". But logically, it can't make things worse and so will make things better in anything from 99% to 0.00001%
Another consideration is how infectious omicron is outside. If there are 50x the virions ejected, wouldn't that result in a significant cloud? If someone with Omicron runs past you in the park breathing heavily, can you trust the viral cloud will disperse enough to not infect you, or are you at as much risk as talking face to face with someone with Delta for 10 minutes at 2 metres distance?
In real terms, the situation is too complex to actually inform the masses, so massive generalisations need to be made to make workable rules.
Put it another way, do you see a significant drop in Flu infections since we started wearing masks? Would you expect it to be lower due to that?
Yes and yes, but the mask wearing isn't in isolation. There have been lockdowns etc., so it's not really possible to separate the impact of the masks from all the other measures in place.
Last year was record low numbers, right?
This year no one is masking and Flu season is normal to higher numbers.
But with the added issue that because of less disease exposure the past two years, people are less resistant to these background diseases. Had people not been wearing masks, we'd have increased Covid spread but also more active resistance. Good luck trying to quantify the pros and cons from that!
