(601as) Numerical Simulation of Reactive Gases Uptake in Lung

The pattern of lung injury caused by the inhalation of reactive gases such as ozone, one of the major air pollutants, is believed to depend on the local dose delivered to different tissue sites in the respiratory tract. In-vivo studies to measure site-specified ozone dose can only be performed with limited scope because they require consideration of the entire respiratory tract, which is impractical due to the complexity of the lung structure and the large number of airways. Therefore, as an alternative, mathematical dosimetry models have been developed. Dosimetry models are predictive tools to estimate the distribution of the reactive gases such as ozone in the lung. The major shortcoming of the previous mathematical single-path dosimetry models is their inability to consider the radial and longitudinal variations in the reactive species concentration distribution within the airways of the lung resulting in the plug flow assumption. To address this shortcoming, we developed the Graetz-based dosimetry model capable of considering both the axial and radial reactive species concentration variations within airways of the lung. The ozone concentration distributions predicted by the model are found to be in excellent agreement with those obtained from three-dimensional numerical simulations in anatomically-accurate airway structures reconstructed from magnetic resonance images of the lungs of rhesus monkeys.