ORIGINAL PAPER Doses from radon progeny as a source of external beta and gamma radiation V. M. Markovic • D. Krstic • D. Nikezic • N. Stevanovic Received: 4 July 2011 / Accepted: 17 March 2012 / Published online: 13 July 2012 Ó Springer-Verlag 2012 Abstract Great deal of work has been devoted to deter- mine doses from alpha particles emitted by 222 Rn and its progeny. In contrast, contribution of beta particles and following gamma radiation to total dose has mostly been neglected so far. The present work describes a study of the detriment of 222 Rn progeny for humans due to external exposure. Doses and dose conversion factors (DCFs) were determined for beta and gamma radiation in main organs and remainder tissue of the Oak Ridge National Laboratory phantom, taking into account 222 Rn progeny 214 Pb and 214 Bi distributed in the middle of a standard or typical room with dimensions 4 m 9 5m 9 2.8 m. The DCF was found to be 7.37 lSv/WLM. Skin and muscle tissue from remainder tissue receives largest dose. Beta and gamma radiation doses from external exposure were compared with alpha, beta, and gamma doses from internal exposure where the source of radioactivity was the lungs. Total doses received in all main organs and remainder tissues were obtained by summing up the doses from external and internal exposure and the corresponding DCF was found to be 20.67 lSv/WLM. Keywords Radon  Dose  Beta  Gamma  DCF Introduction Inhalation of the short-lived radon decay products ( 218 Po, 214 Pb, 214 Bi/ 214 Po) in homes, in the outdoor atmosphere, and at work places contribute the largest fraction to the natural radiation exposure of man (NCRP 1987; ICRP 1981). Radon or rather its decay products are known to repre- sent a risk of lung cancer when inhaled. Additional potential hazards to tissues other than lungs are also rec- ognized. Dose calculations suggest that the ingestion of water that contains high levels of radon can lead to a sig- nificant risk of stomach cancer (NRC 1999). There is also indication that deposition of radon decay products may, under certain circumstances, lead to significant doses to sensitive cells in the skin, again with cancer as a possible consequence (NRPB 1997). A review of risks from radon and its decay products, albeit with emphasis on the lung, has been given elsewhere (NRPB 2000; UNSCEAR 2006). Besides alpha radiation from 218 Po and 214 Po, beta and following gamma radiation are produced during the decay of radon progeny. More specifically, 214 Pb and 214 Bi are short-lived radon progeny, which decay with subsequent emission of beta particles followed by intensive gamma radiation. The beta particles produced show continuous energy spectra with energies up to about 3.3 MeV, and they are much more penetrating than alpha particles. Due to the long range of beta particles and the subsequent gamma radiation, not only the sensitive target layers of the human respiratory tract (HRT) but also the whole lungs and all other organs of the human body are exposed when radon was inhaled. Gamma and beta doses to all organs including lungs due to inhaled radon and thoron progeny were cal- culated recently (Markovic et al. 2009; Nikezic et al. 2010). In addition to inhaled radionuclides, those distributed in indoor atmospheres can also contribute to total dose. This contribution could be significant since the potential alpha energy concentration (PAEC) in indoor air is larger than in the lungs. In other words, a greater number of beta and gamma particles decay in the air and thus could deliver a V. M. Markovic  D. Krstic  D. Nikezic (&)  N. Stevanovic Department of Physics, Faculty of Science, University of Kragujevac, R. Domanovic 12, 34000 Kragujevac, Serbia e-mail: nikezic@kg.ac.rs 123 Radiat Environ Biophys (2012) 51:391–397 DOI 10.1007/s00411-012-0413-1