Scientists have reported that healthy people emit exponentially more aerosol particles from their lungs as they age, both at rest and during exercise.
Older studies had shown that the amount of aerosol particles that people of all ages emitted increased by more than 100-fold from rest to intense exercise. But they investigated the effect of factors such as age, sex, and body mass index only at rest and without considering ventilation.
In an aerosol, very fine solid or liquid particles are suspended in a fluid. For example, air that contains PM2.5 particulate matter can be considered an aerosol.
