Dr Ted Noel - Illustration of mask protection of aerosolized viruses.

This is for demonstration purposes of how ineffective masks are at preventing the spread of aerosolized viruses (>5 microns).

Most arguments suggest that the mask prevents particulates escaping further than distances than without. However, this ignores the natural circulation of air designed into buildings. Rooms are designed to circulate air to prevent stagnant air from collecting in any one point.

It should be noted that the human body (adult) pumps approximately 60 to 150 litres of air per minute. In a standard 450 sqft room one adult human will circulate this full volume of air in 3.5 to 1.4 hours. As small portions of the room are traversed by the occupants, it is suggested a room will be considered fully contaminated within 15mins of an infected person entering a room, regardless of if they wear a mask.

My guess is people have forgotten about those days a sick person comes into work, stays for a couple hours then leaves to recover at home. Inevitably someone at the office gets sick and before you know it everyone has it... which is good as that office is now immune to that cold for the future. I guess we all just forgot those things we used to know.