My position is simply this...there is nothing magical about a COVID-19 viral particle that allows it to impart properties to a drop of salt water allowing it to penetrate materials that are known absolutely will stop ANY OTHER PARTICLE of the same size. Masks DO work just based on that.
And the hypoxia effects this doctor touts, although a real effect, happen only to a tiny minority of people, and are easily relieved by simply taking a break without the mask at a safe distance from others and in a well ventilated area and doing some deep-breathing exercises.
If you are really worried about it, get a phone with an O2 sensor (mine has one), or get a finger oximeter (I got mine on Amazon for sixty bucks just to check the phone (and they "do" agree)). I also tried "with" and "without" wearing a mask, and the "hypoxia effect" was about 1%, which was cleared with a couple of deep breaths.
In "civilian" use, I don't see any significant number of people wearing a mask for much more than an hour at a time. Put it on when you before getting out of your car, go shop, return to car and take it off...then use hand sanitizer.
If as much time was spent EDUCATING people on CORRECT mask usage rather than trying to sell the false meme of "masks don't work", we would all be a lot better off.
Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Personal Protective and Environmental Measures
Abstract
There were 3 influenza pandemics in the 20th century, and there has been 1 so far in the 21st century. Local, national, and international health authorities regularly update their plans for mitigating the next influenza pandemic in light of the latest available evidence on the effectiveness of various control measures in reducing transmission. Here, we review the evidence base on the effectiveness of nonpharmaceutical personal protective measures and environmental hygiene measures in nonhealthcare settings and discuss their potential inclusion in pandemic plans.
Although mechanistic studies support the potential effect of hand hygiene or face masks, evidence from 14 randomized controlled trials of these measures did not support a substantial effect on transmission of laboratory-confirmed influenza.
We similarly found limited evidence on the effectiveness of improved hygiene and environmental cleaning. We identified several major knowledge gaps requiring further research, most fundamentally an improved characterization of the modes of person-to-person transmission.
https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article