en Medical Physics Medical Physics تحقيق بديع Original Research <div style="text-align: justify;">Background: Naturally occurring radioactivity is a root cause of human exposure to harmful radiation. The occupational exposure hazard due to natural radionuclides occurring in drilling wastes is especially important in this regard. In this study the concentration of radionuclides namely ²³²Th, ²²⁶Ra and ⁴⁰K were assessed in soil samples that were taken from various oil drilling areas. Methodology: 10 samples were collected and sealed for two months to ensure the secular equilibrium between ²²⁶Ra and ²³²Th, and their respective radioactive progenies. The concentration of radionuclides in samples was measured by gamma spectroscopy. Descriptive and analytical statistics were used in order to analyze the data. Results: the results showed the average absorbed dose rates (D), annual effective dose (AED), Radium equivalent activity (Raeq) and various hazard indexes(Hex, Hin and I&gamma; ) for samples were 38.22 nGy/h, 0.046 mSv/y, 81.032 Bq/Kg, 0.21, 0.31 and 0.59, respectively.</div> Conclusions: The mean activity concentrations were lower than the world mean values, according to the radiation protection criteria that identified by UNSCEAR. Exposure, natural radioactivity, radiation dosages, drilling industry, hazard index. 49 54 http://ijrr.com/browse.php?a_code=A-10-2055-85&slc_lang=en&sid=1 J. Deris 7900319475328460019945 7900319475328460019945 No Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran B. Fouladi Dehaghi bdehaghi@gmail.com 7900319475328460019946 7900319475328460019946 Yes Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran