- Then how do we explain the military recruit study? How come masks did not offer much protection there? Easy – because, in that study, “standard” masks (non-N95’s) will not protect you if you violate any of the four main risk factors that predict transmission within indoor spaces; Density, Duration, Dimensions, and Draft:
- Density – # of people in the room
- Duration – # of hours spent in the room
- Dimensions – # of square feet and ceiling height of the room
- Draft – amount of fresh air entry/speed of air flow
If you violate any of the four D’s above in a significant way, you will get sick,
even with a “standard” mask. The military recruit study showed that, in the group wearing masks, nearly all transmission occurred between roommates or within platoons, and it should be noted that these situations violate all the four D’s above. They spent time indoors, among a high
density of recruits, for prolonged
durations, in small
dimensioned rooms, with likely little
draft. Standard cloth or surgical masks just won’t offer sufficient protection in these settings if an infected person is in their midst.
covid19criticalcare.com
eu.usatoday.com
