COMPARISON OF DIFFERENT MODELING APPROACHES IN CURRENT LUNG DOSIMETRYMODELS

Theoretical predictions of bronchial doses due to inhaled radon decay products require assumptions about the morphology of the human lung, t he physics of particle transport and deposition, the physiology of cle arance mechanisms, and the histology of the bronchial epithelium. In t his research effort, the effects of different modeling assumptions on deposition, clearance, and cellular dosimetry were investigated in a s ystematic manner. The resulting range of cellular doses obtained refle cts the systematic as well as statistical uncertainty of current dose predictions for lung cancer risk assessment. This comparison of differ ent modeling philosophies suggests that the most critical factors are: inter-subject variability of airway dimensions; inhomogeneity of part icle deposition and mucociliary clearance patterns; and distribution, frequency, and relative radiosensitivity of target cells within the br onchial epithelium. Copyright (C) 1996 Elsevier Science Ltd.