en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: Indoor levels of ²²²Rn in some residential areas in Ramsar are as high as 31,000 Bq/m3, resulting in mean internal exposures up to 71 mSv/y. The main goal of this study was to develop a simple mathematical model for predicting radon concentrationfrom gamma radiation level in dwellings located in high background radiation areas (HBRAs) and a nearby normal background radiation area (NBRA) of Ramsar. Materials and Methods: The levels of gamma background radiation and indoor radon were measured in 350 dwellings located in normal and high background radiation areas (210 dwellings from HBRAs and 140 dwellings from NBRAs). Moreover, data about the most important environmental factors such as temperature and humidity as well as the inhabitants&rsquo; nutrition were collected. Results: The mathematical relationship between the gamma radiation level and indoor radon concentration in NBRAs and HBRAs is introduced in this study. The findings obtained in this study clearly indicate that in normal and high background radiation areas of Ramsar the majority of confounding factors such as the type of building materials and ventilation in different houses are almost identical. Therefore, the level of gamma radiation can be used as a strong predictive tool for radon concentration. Conclusion: As radon concentration in indoor air strongly varies with time, the simple mathematical methods developed in this study, can help health physicists and environmental scientists have an estimate of the mean radon level in these areas.</div> Mathematical model, indoor radon, high background radiation areas, Ramsar, prediction. 143 147 http://ijrr.com/browse.php?a_code=A-10-1-849&slc_lang=en&sid=1 M. Haghani 7900319475328460015434 7900319475328460015434 No Nuclear Engineering Department, School of Mechanics, Shiraz University, Shiraz, Iran K. Haddad hadadk@shirazu.ac.ir 7900319475328460015435 7900319475328460015435 Yes Nuclear Engineering Department, School of Mechanics, Shiraz University, Shiraz, Iran S.M.J. Mortazavi mortazavismj@gmail.com 7900319475328460015436 7900319475328460015436 No Medical Physics and Medical Engineering Department, Shiraz University of Medical Sciences, Shiraz, Iran R. Faghihi 7900319475328460015437 7900319475328460015437 No Nuclear Engineering Department, School of Mechanics, Shiraz University, Shiraz, Iran A. Pirouzmand 7900319475328460015438 7900319475328460015438 No Nuclear Engineering Department, School of Mechanics, Shiraz University, Shiraz, Iran M. Faraz 7900319475328460015439 7900319475328460015439 No Medical Physics and Medical Engineering Department, Shiraz University of Medical Sciences, Shiraz, Iran