Abstract |
A dosimetry simulation model has been developed for predicting the local absorption of ozone (03) in the lower respiratory tract (LRT) of animals and man. The model takes into account species LRT anatomy and ventilatory characteristics, transport in the lumen and air spaces, loss of 03 to the liquid lining, and transport and chemical reactions in the liquid lining and underlying tissues and capillaries. Basic biological concepts and the mathematical formulation of the model are briefly outlined and the results of several investigations presented. Predicted values of LRT uptake are compared to experimental 03 uptake data in humans, showing good agreement over the range of experimental tidal volumes and breathing frequencies. The effect of airway path distance on centriacinar ozone dose is explored; large variations in dose for the first alveolated ducts in a rat are predicted. Human and rat generational doses versus generation are plotted together for comparison; the curves demonstrate a remarkable similarity with regards to shape and structure. |