Distribution of natural radionuclides and assessment of the associated radiological hazards in the rock and soil samples from a high-level natural radiation area, Northern Iran

Distribution and possible radiological hazards of natural radionuclides in the rock and soil samples from a region in Northern Iran were investigated. Rock and soil samples were analyzed to quantify radionuclide variations on the basis of mineralogical composition and physicochemical properties, respectively. The highest activity concentrations and radiological hazard indices were related to Arud granitic body and Ramsar’s soil. 40 K-bearing feldspars and 226 Ra-rich carbonates are the main radiation contributors in the study area. Rock samples with high concentrations of 226 Ra, also, contained high U values, while Ramsar’s soils, which were rich in 226 Ra, did not show abnormal U values.