The understanding I had, was that someone with environments experience heard that and was confused because when it comes to pollution, the particle size is 100 microns that they have to worry about. It didn’t line up. And then we come to find out that medical science was potentially inconsistent here based on some specific / older assumptions.

I remember my sister, a nurse in a major Chicago hospital, telling me in April 2020 that they were finding Covid virus matter outside of patients rooms / in hallways and that didn’t make sense since it couldn’t be airborne. She was like “they keep saying it’s not airborne, but clearly something is allowing it to leave patients rooms”. The hospital at the time decided to convert all Covid floors to negative pressure after that.