(Mental image – a 6’x6’x6’ box, great air circulation within, no external inputs)
Viral Load – SARS-CoV-2 infection occurs after inhaling 10,000 particles … less, and your natural defenses overwhelm the invader
Cloth Mask – filters 75% of airborne droplets, 0% of fomites (desiccated viral particles)
N95 Mask – filters 95% of airborne droplets, 25% of fomites
Quiet Talkers – Expel 3,000 infective droplets/min
Loud Talkers – Expel 8,000 Infective droplets/min
Choir singers – Expel 28,000 Infective droplets/min
Workout/Athletes – Expel 30-40,000 Infective droplets/min
Cough – 30,000 infective particles/instance
Sneeze – 400,000 infective particles/instance
In these admittedly very simplified models, what hopefully becomes clear is that what you want to avoid is prolonged exposure to any level of infective particles ... long term exposure to asymptomatic, infective carriers in settings like offices, cubicles, salons, tattoo parlors, etc... *even while wearing a mask* is as bad as someone sneezing in your face
Simplified Office/Salon/Haircutting example
Fellow Cubicle dweller - Quiet talker - 3,000 particles/min * 20 minutes = 60,000 particles
Reduce by 75% with cloth mask = 15,000 particles (>10,000 you’re infected)
Grocery Store example
no conversations and only transient close contact (e.g. passing an aislemate)
wearing a cloth mask
3,000 particles total exposure
Reduce by 75% with cloth mask – 750 particles (>10,000 you’re infected)
Some of my neighbors are talking about opening pools, since "chlorine inactivates the virus" ... assuming no one is breathing water, the virus is going to be as active in the air the swimmers are breathing as in any sports environment ... we're not sure what role humidity plays in enabling/disabling the virus ... given the level of exertion, I'd assume just as much as in basketball, soccer, boxing, etc...
These numbers are approximate but not far off from real values ... Do the modeling yourselves