The only thing I could imagine is that the masks could make it worse because of something else. Say, for a runner gettin x% less O2 is worse, risk wise, than to

The only thing I could imagine is that the masks could make it worse because of something else. Say, for a runner gettin x% less O2 is worse, risk wise, than to use the mask for viral protection This was not in the article, I am just speculating on a possible reason (not applicable here). BTW our gouvernement (French) was telling us that story of no masks for the first weeks and it was already ridiculous at that time.