Influence of Human Lung Morphology on Particle Deposition.

Thoracic airway calibers were estimated in 15 healthy subjects from gravitational losses during respiratory pauses of particles inhaled as aerosol boluses to different volumetric depths in the respiratory tract. Intersubject variability of thoracic airway dimensions and particle deposition for controlled and spontaneous mouth-breathing were correlated by Spearman's rank correlation analysis. The correlations between deposition of particles in the diameter range 1 - 5 μm and aerosol derived lung morphology suggest that the intersubject variability of particle deposition is primarily due to morphological differences between individuals. They also confirm the current understanding of behavior in the human respiratory tract of particles larger than 1 μm in diameter: with increasing particle size, the site of deposition is shifted proximally in the lungs. &nbsp