Numerical prediction of the focal sites of ozone-induced tissue injury in the respiratory tract

Numerical simulations of ozone transport and uptake in an anatomically-accurate model of the respiratory tract of a Rhesus monkey were performed. The model geometry was created using three-dimensional reconstruction of MRI images of the respiratory tract, including the larynx and the first thirteen generations of the tracheobronchial tree. An unstructured mesh was generated for the resulting structure, and three-dimensional flow and concentration distributions were obtained through numerical solution of the Navier-Stokes, continuity, and species convection-diffusion equations. A quasi-steady diffusion-reaction model was used to account for the interaction between O₃ and endogenous substrates in the respiratory tract lining fluid. Hotspots of O₃ flux on the walls were identified for steady inspiratory flow under quiet breathing conditions.