Biological variability of particle deposition in the human respiratory tract during controlled and spontaneous mouth-breathing.

Abstract

Total particle deposition in the respiratory tract of 20 subjects was experimentally determined for both controlled and spontaneous steady mouth-breathing of uncharged monodisperse aerosols in the diameter range 0.5 to 7.5 μm. A small intrasubject but a large intersubject variability of deposition was found. For spontaneous breathing the intersubject variability of deposition is determined by morphological factors but the intersubject variability of deposition rate by physiological factors.