“Where is Mike Phelps hiding his air tank?”
Everybody there is breathing the same air. Wouldn’t be surprised if he has an air purifier in his room. I would.
Air “purifiers” can’t remove sub-micron particulate matter; despite the cries for abatement, there is a practical limit on controls.
There is a growing focus on these smallest particles and their ability to be breathed deeply into the lungs where they remain and collect, yet current removal technology has not caught up with detection methodolgy.