ASSESSMENT OF NATURAL RADIOACTIVITY LEVELS AND RADIATION HAZARDS IN AGRICULTURAL SOIL AND TRANSFER IN WHEAT IN THE REGION OF NORTH MACEDONIA.

Bad agricultural practices, such as the excessive use of fertilizers, often lead to the accumulation of radioactive elements in the soil and further in the crops. This research aims to determine the activity concentration levels of radionuclides of 226Ra, 232Th, and 40K in soil and wheat samples. At the same time, an assessment was made of the radiation hazard indices from natural radioactivity as well as the transfer from soil to the wheat of the studied radionuclides. A total of 92 soil and wheat samples were collected in the studied area (the western part of the country). The samples were measured on an instrument - a gamma spectrometer (Canberra Packard) using the GENIE 2000 program. In this study, it was observed that the specific activity of 40K, 226Ra, and 232Th in the soil is not uniform and probably differs depending on the geological or typographical characteristics of the area as well as the applied agricultural techniques and agrochemicals. The average activity concentrations of 226Ra, 232Th, and 40K in the soil samples were 35.86 ± 1.55 Bq/kg, 37.40 ± 2.86 Bq/kg, and 165.78 ± 4.05 Bq/kg, respectively, while the average values for wheat were 0.63 ± 0.20 Bq/kg, for 226Ra 0.40 ± 0.08 Bq/kg, for 232Th and for 40K 61.18 ± 3.50 Bq/kg. The calculated mean values of radium equivalent activity Raeq, Dout, and Din were 102.98 Bq/kg, 46.72 nGy/h, and 77.93 nGy/h respectively. The soil-to-wheat transfer factor of naturally occurring radionuclides was in the following order: 40K > 226Ra > 232Th. This shows that there is no risk of radiation contamination in the tested wheat soils and there is no considerable risk to human health. [ABSTRACT FROM AUTHOR]