Aerosol Deposition in the Human Respiratory System

摘要

Attempts were made to develop mathematical models for the deposition of aerosols in the human respiratory system. Expressions were obtained for the mean deposition efficiency for nasal inspiration, nasal expiration and mouth inspiration. A determination was made of statistical properties associated with each deposition efficiency due to intersubject and intrasubject variabilities. Expressions were then derived for head deposition with combined nose and mouth breathing. In the lung, deposition is a result primarily of impaction, sedimentation, and diffusion. While there was no adequate model for impaction, several deposition formulae for sedimentation have been derived as well as ones for diffusion. Studies have also been made of the particle charge effect, as the electrostatic image force on a particle contributes to its deposition. There is, however, a threshold charge per particles below which the particle charge has no effect on deposition. Deposition data on ultrafine particles is scarce due to the difficulties in conducting proper experiments.