A study of environmental radioactivity measurements for Cankiri, Turkey

This study is the first to assess the level of background radiation for the Cankiri province of Turkey. Indoor air radon concentrations were determined using Columbia Resin-39 nuclear track detectors and the average Rn-222 activity was found to be 44 Bq m(3) (equivalent to an annual effective dose of 1.1 mSv). Measurements of gamma doses in outdoor air were performed using a portable plastic scintillation detector and the average gamma absorbed dose rate was found to be 8 R h(1) (corresponding to an annual effective dose of 87.7 Sv). Radionuclide activity concentrations in soil samples were measured through gamma-ray spectrometry and the average activities were determined as 17.7, 22.3, 357 and 4.1 Bq kg(1) for the radionuclides U-238, Th-232, K-40 and Cs-137, respectively. The average annual effective dose from the natural radioactivity sources (U-238 series, Th-232 series and K-40) was calculated to be 44.4 Sv. Radioactivity levels of drinking water samples were carried out using a low-background proportional counter and the average gross alpha and beta activities were obtained as 0.25 and 0.26 Bq l(1), respectively (equivalent to an annual effective dose of 184 Sv). The average radon concentrations in indoor air and the average radionuclide activities in soil were found to be lower than most Turkish cities while higher levels of outdoor gamma dose rate and water radioactivity were observed. The results of this study showed that the regions background radioactivity level differs considerably from the reported data for Turkish cities.