3 ms·
Same reason that we care about the concentration of PM2.5 particles in the atmosphere. Once we inhale them they manage to reach the very end of our lungs.
by whatever1 6y ago
Same reason that we care about the concentration of PM2.5 particles in the atmosphere. Once we inhale them they manage to reach the very end of our lungs.
- EForEndeavour 6y agoIs it? That's different from the counterintuitive N95 filtration efficacy. PM2.5 designates particles of diameter 2.5 microns and smaller, and I've read nothing that implies particles smaller than 2.5 microns are somehow easier for the respiratory tract to keep out of the lungs. The graph of filtration efficacy as a function of particle size is U-shaped for N95 masks, but not for the human respiratory tract.