Determination of natural radioactivity and associated radiological hazard in excavation field in Turkey (Oluz Höyük)

The level of natural radioactivity may be varied with the increase in dependence of the depth into the earth. In present study, soil samples from different depths were collected in Oluz Höyük excavation area. The radionuclide concentrations in soil samples were determined by gamma-ray spectrometer which contains 3" × 3" NaI(Tl) detector connected to multichannel analyser. The photopeaks at 1460, 1764, and 2615 keV due to ⁴⁰K, ²²⁶Ra and ²³²Th, respectively, have been used. The obtained activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th ranged from 656.03 to 1791.85 Bq/kg, 62.39 to 180.93 Bq/kg and 48.31 to 125.43 Bq/kg, respectively. To assess the radiological hazard of the natural radionuclides content in the soil samples of these area, the radium equivalent activities (the minimum value was 181.99 Bq/kg and the maximum value was 497.97 Bq/kg), the absorbed dose rate (the minimum value was 86.83 nGy/h and the maximum value was 237.22 nGy/h), annual effective dose rate (the minimum value was 0.11 mSv/y and the maximum value was 0.29 mSv/y) and external hazard index (the minimum value was 0.49 and the maximum value was 1.35) were calculated using measured activities.