What happens when an infected person sneezes in a room?
Perhaps this is clearer to you. As you can see from the video of this 3D simulation, the virus particles propagate very quickly, around those who have sneezed or who have had a cough. The same person can be, perhaps even asymptomatic.
A whole series of activities therefore makes no sense
It therefore makes no sense to keep the mask under your nose or take it off when you cough. Above all it is very dangerous to enter a closed room, where there is a person with a mask under his nose. Same thing does not make sense to run in Corso Italia, next to people and blow your breath in their face or even worse to think of being in an office with the windows closed and well sealed for hours, without a mask, so much the other has it. Even the PPE after a couple of hours have to be replaced and must be renewed, also because if you think about it, the aerosol of other people by dint of depositing on your mask after a while will overburden the mask. The windows must be open and there must be a strong recirculation of air and not simply the open window with no wind or slightly open with a simple crack.
The simulation of the Bambin Gesù
With this 3D simulation created by the Baby Jesus, the particle propagation of aerosols contaminated by the virus and its propagation inside a room with air conditioning at half power and then at full power is clearly clarified. The study conducted by the Bambino Gesù Pediatric Hospital with Ergon Research and the Italian Society of Environmental Medicine (SIMA).