Determination and mapping of radionuclide distributions in provincial and district centers located at different distances from metsamor nuclear power plant

This study aims to determine and map the distribution of radionuclides (3H, 226Ra, 232Th, 40K, and 137Cs) in soil, water, and local agricultural products in some provinces of eastern Turkey located near the Metsamor Nuclear Power Plant in Armenia. For this purpose, regions located at radii of 40, 80, 120, and 160 km towards the province of Iğdır, with Metsamor Nuclear Power Plant at the center, were included in the study. These regions comprised 28 provincial and district centers, including Aşağıalican village of Karakoyunlu district in Iğdır, which is the closest settlement to the Metsamor Nuclear Power Plant. A total of 29 soil, 32 water, and 12 local agricultural product samples were collected from these regions. The activity concentrations of 226Ra, 232Th, 40K, and 137Cs in the soil samples were found to range between 7,90 - 23,44 Bq/kg, 7,11 – 33,55 Bq/kg, 132,54 – 502,69 Bq/kg, and 0,33 – 17,61 Bq/kg, respectively. In the water samples, the activity concentrations of 226Ra, 232Th, 40K, and 3H ranged from 1,41 – 3,48 Bq/L, 0,79 – 2,12 Bq/L, 13,11 – 20,54 Bq/L and 1,28 – 4,64 Bq/L, respectively. The activity concentrations of 226Ra, 232Th and 40K in the local product samples were between 1,79 – 9,09 Bq/kg, 0,92 – 4,89 Bq/kg and 83,38 – 293,27 Bq/kg, respectively. Furthermore, the soil-to-plant transfer factor values were calculated. Additionally, daily radionuclide intake (Dint), annual effective dose (Eeff), and lifetime cancer risk (LCR) values were calculated to evaluate the radiological hazards associated with the consumption of the analyzed water and agricultural products. The obtained values were compared with the recommended limit values of international organizations. As a result, this study demonstrated that the consumption of the analyzed water and some agricultural product samples does not pose a radiological risk to human health. Moreover, Pearson correlation coefficient analysis was conducted to investigate the relationship between the examined radionuclides and distances and altitudes from the Metsamor Nuclear Power Plant. A moderate positive correlation (0,4–0,6) was observed for 226Ra, 232Th and 40K radionuclides, while a weak positive correlation (0,2–0,4) was found for the ¹³⁷Cs radionuclide.