Apologies if this has been answered before but what studies are there showing wearing of masks actually rescue transmission ?
I fail to see how the wafer thin paper surgical masks actually stop a virus ?
Is it just a sort of placebo affect where if someone is wearing a mask/ facecovering you tend to distance yourself more from them ?
I'd be interested if there are any links you can point me towards.
This has been asked, and answered, before. Plenty available from reputable organisations and sources on line.
I don't get the opposition to masks. It is a zero risk intervention, and you are being asked by owners of shops and other buildings to wear one. Why would you not, at least as an act of common courtesy, do so? I just don't get it.
In terms of the broader question of evidence, there are usually various levels of evidence available, and these combine to inform a judgment.
The first thing is that randomised controlled trials are not necessarily needed if something stands to reason. There is no RCT that falling out of an airplane with a parachute offers better outcomes than falling out without one. But it kinda stands to reason. It also stands to reason that covering your nose and mouth might change the nature of what you breathe out. Some masks are better than others, clearly, but as part of a multi-layer strategy with vaccination, social distancing and ventilation, it seems reasonable they might have an effect. You may believe they don't do much, but what's the harm?
It is also worth noting that countries with established mask practices, for example in Asia, have much lower rates of infection, despite high occupancy multi-generational household.
Finally, there is a behavioural aspect. Masks provide a visible warning to practice caution. Not everybody responds to that, but some do, and a little bit of each of a range of strategies add up.