Then explain how medical workers, sanitation workers, tattooists, nail technicians etc...all wear masks for hours on end daily and have zero issues with low oxygen. Literally for decades. I don’t follow CNN like gospel, or any specific outlet, but I do make efforts to read from people who are reasonably educated and have a history of decent work. Or, in cases like this regarding masks, I ask the many workers I know who currently wear and who did wear (retired) masks on the regular. Believe it or not, not a single person has run into oxygen shortages whilst masked. And if you need to know, the three I recently spoke to were a tattoo artist, nursing home nurse (who had Covid and now recovered), a cardiac nurse, personal trainer, and a retired nursing home nurse.