Particles
Size of the particles is critical
- 5um diameter or greater
- Upper respiratory tract
- Can be generally easily eliminated via coughing, sneezing, GI absorption
- 2-5um diameter
- reach trachiobronchial region before they impact the lung surface
- Eliminated as above
- Less than 1um diamete
- reach alveolar regions of the lung
- Absorption then dissolution and absorbtion into the bloodstream
- Or phagocytosed by alveolar macrophages
- Or remain