Lung dose and lung cancer risk by inhalation of radon daughters

The inhalation of short-lived radon daughters constitutes the most important occupational radiation exposure in mines, particularly in uranium mines. Among some groups of miners exposed in the past to relatively high radon levels, an excess lung cancer incidence has been observed. In addition to this occupational hazard, the observed radon levels in domestic houses indicate that the inhalation of short-lived radon daughters seems to be the most important component of the radiation exposure of the population from natural sources. For the quantification and judgment of the radiological impact by inhalation of radon daughters in mines as well as in houses, it is necessary to estimate the relationships between the inhaled activity or potential alpha (α) energy of these radionuclides, the dose to target tissues in the lung, and the possible associated lung cancer (LC) risk. It is the purpose of this paper to give a condensed review of our present knowledge in this field and to indicate the main gaps and uncertainties where future research seems necessary