Radon decay products in realistic living rooms and their activity distributions in human respiratory system

In this study, the individual activity concentrations of attached short-lived radon decay products (218Po, 214Pb and 214Po) in aerosol particles were measured in ten poorly ventilated realistic living rooms. Using standard methodologies, the samples were collected using a filter holder technique connected with alpha-spectrometric. The mean value of air activity concentration of these radionuclides was found to be 5.3±0.8, 4.5±0.5 and 3.9±0.4 Bq m-3, respectively. Based on the physical properties of the attached decay products and physiological parameters of light work activity for an adult human male recommended by ICRP 66 and considering the parameters of activity size distribution (AMD = 0.25 μm and σg = 2.5) given by NRC, the total and regional deposition fractions in each airway generation could be evaluated. Moreover, the total and regional equivalent doses in the human respiratory tract could be estimated. In addition, the surface activity distribution per generation is calculated for the bronchial region (BB) and the bronchiolar region (bb) of the respiratory system. The maximum values of these activities were found in the upper bronchial airway generations. (authors)