Facemasks in the COVID-19 era: A health hypothesis
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7680614/
Summary; Masks are worse than useless, they’re detrimental to your health.
I cut a bunch of small horizontal slits in my single layer cotton mask.
Makes breathing a lot easier, and they’re not obvious.
No one has ever challenged me.