Always has been particulates in the air and always will be. There are areas where naturally occurring asbestos creates hazardous levels in the air. The respiratory system has evolved to handle most of this via a layer of mucus that is excreted in the lungs and carried upward and out (to be swallowed) by the constant movement of the cilia lining the airways. You were likely taught this in biology or health class at one point.

https://www.soils.org/publications/sssaj/pdfs/77/6/2192