I have read over the report of that study now 3x. Maybe I'm extra dense today (menopause) but I cannot find the results of the petrie dishes that the participants coughed into. THAT would reveal if the virus from the cough actually became airborne (landed in the dish) right? The swab of the outer surface of the mask proves that it went as far as......well..... the outer surface of the mask. In the results of that study, they do mention this, "Although it is possible that virus particles may cross from the inner to the outer surface because of the physical pressure of swabbing, we swabbed the outer surface before the inner surface." Virus resting on the outer surface of the wear's mask, in and of itself, doesn't pose a threat to other persons passing by and inhaling the same air, as the particles are not aerosol.