The Monte Carlo Assessment of Photon Organ Doses from 222Rn Progeny in Adult ORNL Phantom

Document Type : Original Paper


Physics Department, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran


The potential hazards posed by exposure to radiation from radon have been of great concern worldwide, since it is especially associated with increased risk of lung cancer. Some radioisotopes of radon progeny deposited in the human lungs emit β particles followed by the γ rays. While γ rays are comparatively less damaging to the respiratory system than α and β particles, it is the principal deposited energy in other organs.
Materials and Methods
In order to establish a quantitative estimate of hazards caused by the radiation, this paper studies the photon absorbed doses from radon progeny in all major organs of the human body through a simulation of the Oak Ridge National Laboratory (ORNL) adult phantom using MCNPX2.4.0 Monte Carlo code and calculations which were performed in photon/electron mode.
Effective dose due to photons from radon progeny deposited in the human lungs was about 1.69 µSvWLM-1. Based on UNSCEAR2006 reports, the effective dose of these photons per year is about 5.76´10-1mSv  in for radon concentration of 31000 Bq/m3  (the maximum concentration of radon in Iran). Therefore, this value is comparable with 1mSv (The annual allowable effective dose).
The dosimetry of photons particularly in areas with high levels of exposure to radon and radon's decay products is important because all organs receive the photon absorbed dose from radon progeny.


Main Subjects

  1. ­Nikezic D, Yu KN. Dosimetric model of human lung and associated computer programs. Indian J Phys. 2009; 83(6):759-75.
  2. International Commission on Radiological Protection. Human Respiratory Model for Radiological Protection. Ann ICRP. 1994;24:1-120.
  3. Martin JS. The Physics of Radiation Protection. Second, editor: John Wiley & Sons Canada, Limited; 2006.
  4. Yu KN, Lau BM, Nikezic D. Assessment of environmental Radon hazard using human respiratory tract models. J Hazard Mater. 2006;132(1):98-110.
  5. Markovic VM, Krstic D, Nikezic D. Gamma and beta doses in human organs due to radon progeny in human lung. Radiat Prot Dosimetry. 2009;135(3):197-202.
  6. Eckerman KF, Cristy M. Ryman JC. The ORNL Mathematical Phantom Series, Informal Paper. Available from: Accessed Dec 15, 2008.
  7. Hakimabad HM, Motavalli LR. Evaluation of specific absorbed fractions from internal photon sources in ORNL analytical adult phantom. Radiat Prot Dosimetry. 2008;128(4):427-31.
  8. Ulanovsky AV, Minenko VF, Korneev SV. Influence of measurement geometry on the estimate of 131I activity in the thyroid: Monte Carlo simulation of a detector and a phantom. Health Phys. 1997;72(1):34-41.
  9. Ulanovsky AV, Eckerman KF. Absorbed fractions for electron and photon emissions in the developing thyroid: fetus to five-years old. Radiat Prot Dosimetry. 1998;79(1-4):419-24.
  10. Table of Radioactive Isotopes of ENDF/IV. Periodic Table linked to decay data for known isotopes of each element. html
  11. International Commission on Radiological Protection. Recommendations of the International Commission on Radiological Protection. Ann ICRP. 2007;103:1-34.
  12. Chart of Radioactive Nuclides. Available from Accessed Dec 15, 2008.
  13. Input files with ORNL-mathematical phantoms of the human body for MCNP-4b. Available from Accessed Dec 15, 2008.
  14. Cristy M, Eckerman K.. Specific Absorbed Fractions of Energy at Various Ages from Internal Photon Sources; pp. V1–V7, ORNL/TM-8381, Oak Ridge, TN: Oak Ridge National Laboratory; 1987.
  15. Briesmeister JF. MCNP - A general Monte Carlo N-Particle transports Code. Version 4C Ed. Los Alamos New Mexico: Los Alamos National Laboratory 2000.
  16. Nikezic D, Yu KN. Micro dosimetric calculation of absorption fraction and the resulting dose conversion factor for radon progeny. Radiat Environ Biophys. 2001; 40(3):207–11.
  17. Source and effect of ionizing radiation. New York: United Nations Scientific Committee on the Effect of Atomic Radiation. Available from: Accessed Aug 10, 2012.