Uncertainties on the dose delivered to the respiratory tract after radon exposure

Irradiation of the different tissues of the respiratory tract by radionuclides of natural origin is mainly related with exposure to radon and its short-lived decay products. The dose to the different regions of the lung arising from inhalation of radon progeny cannot be measured directly. It must be calculated using models which take into account the various processes involved: inhalation, deposition, clearance and decay of radon progeny in the airways of the lung. This paper reviews the main historical dosimetric models and the different morphometric models used for dosimetric purpose. The new Human Respiratory Tract Model for Radiological Protection (ICRP) and the influence of the localisation and distribution of target cells and that of deposition and clearance parameters on dose calculations are described.A comparison between the different dosimetric models and the influence of modelling variables on the uncertainties of dose calculations are addressed. (author)