This is information that other specialists, as well as the major state and global health agencies, and, of course, the media, should have been sharing all along. So far, the dangers of hypoxia (deoxygenation) and hypercapnia (CO2 overload) have been noted only in a few articles, by Dr. Russell Blaylock and Dr. Alan Palmer.
If you’re going to wear a mask to keep yourself “safe,” at least do some research into the dangers, as well as the effectiveness, of that practice.