Age-dependent inhalation doses to members of the public from indoor short-lived radon progeny

Abstract

The main contribution of radiation dose to the human lungs from natural exposure originates from short-lived radon progeny. In the present work, the inhalation doses from indoor short-lived radon progeny, i.e., (218)Po, (214)Pb, (214)Bi, and (214)Po, to different age groups of members of the public were calculated. In the calculations, the age-dependent systemic biokinetic models of polonium, bismuth, and lead published by the International Commission on Radiological Protection (ICRP) were adopted. In addition, the ICRP human respiratory tract and gastrointestinal tract models were applied to determine the deposition fractions in different regions of the lungs during inhalation and exhalation, and the absorption fractions of radon progeny in the alimentary tract. Based on the calculated contribution of each progeny to equivalent dose and effective dose, the dose conversion factor was estimated, taking into account the unattached fraction of aerosols, attached aerosols in the nucleation, accumulation and coarse modes, and the potential alpha energy concentration fraction in indoor air. It turned out that for each progeny, the equivalent doses to extrathoracic airways and the lungs are greater than those to other organs. The contribution of (214)Po to effective dose is much smaller compared to that of the other short-lived radon progeny and can thus be neglected in the dose assessment. In fact, 90 % of the effective dose from short-lived radon progeny arises from (214)Pb and (214)Bi, while the rest is from (218)Po. The dose conversion factors obtained in the present study are 17 and 18 mSv per working level month (WLM) for adult female and male, respectively. This compares to values ranging from 6 to 20 mSv WLM(-1) calculated by other investigators. The dose coefficients of each radon progeny calculated in the present study can be used to estimate the radiation doses for the population, especially for small children and women, in specific regions of the world exposed to radon progeny by measuring their concentrations, aerosol sizes, and unattached fractions.

Measurement of 131I activity in air indoor Polish nuclear medical hospital as a tool for an internal dose assessment

“…The SAAM II software (Epsilon Group, VA, USA) was used for the calculations. This overall methodology has already been successfully applied previously (Brudecki et al 2014 , 2017a , b ; Li et al 2008 ). The radiation-weighted S w coefficients were calculated separately for males and females, with the SEECAL program (Oak Ridge National Laboratory, Oak Ridge, TN, USA).…”

Dose estimation derived from the exposure to radon, thoron and their progeny in the indoor environment

“…Since the equilibrium factors vary with environmental factors, these factors have been estimated independently for individual dwellings separately. Note that with new radon dosimetry currently elaborated by the ICRP, the doses could be a factor 2 to 3 higher 30 31 .…”

Evaluation of exposure to radon and radon progeny in an underground tourist cavern and its connected buildings.

“…The differences in the models are the regional deposition fractions predicted for a standard worker, the number of nuclear transformations estimated by the models due to differences in how clearance from the lungs is modeled, and how the dose to each region of the lung is calculated [Winkler-Heil et al 2007]. Other investigators have derived DCFs using various methods and parameters that vary between 6 and 20 mSv per WLM [Brudecki et al 2014]. Outside the United States, OELs have been established by various agencies and organizations and include legal and recommended limits.…”