HUMAN NASAL PASSAGE PARTICLE DEPOSITION - THE EFFECT OF PARTICLE-SIZE, FLOW-RATE, AND ANATOMICAL FACTORS

This study determined the effect of particle size, how rate, nostril s hape, and nasal passage geometry on nasal particle deposition efficien cy (PDE) in ten healthy, nonsmoking adults (seven males, three females ). A polydispersed (1-10-mu m diameter) aerosol was drawn by unidirect ional flow in through the nose and out through the mouth. Three consta nt how rates of 15, 25, and 35 l/min were used in this study. The nasa l PDE was calculated by measuring size and concentration of aerosol en tering the nose (C-in) and exiting the mouth (C-out), and was defined as (C-in - C-out)/C-in for each particle size and flow rate. A mixed n onlinear model was used to fit the PDE to an equation using particle a erodynamic diameter, flow rate, nostril length to width ratio (ellipti city, E), and minimum nasal cross-sectional area (A(min)). Statistical analyses show that all above factors affect particle deposition in th e nasal passage. Even after inclusion of the above factors, there rema ins a large intersubject variation in deposition. Future studies shoul d evaluate the effect of middle and posterior nasal passage geometry o n nasal particle deposition. (C) 1998 American Association for Aerosol Research.