DETERMINATION OF THE VERTICAL DISTRIBUTION OF ^sup 226^Ra, ^sup 232^Th, ^sup 40^K AND ^sup 137^Cs IN SAMPLES OF CULTIVATED SOIL TAKEN IN THE VICINITY OF CERTAIN CITIES IN REPUBLIC OF MACEDONIA

The purpose of this research was focused on determination of the concentrations of activity of ^sup 226^Ra, ^sup 232^Th, ^sup 40^K and ^sup 137^Cs in the soil samples collected from cultivated soil close to several larger cities in the Republic of Macedonia (Tetovo, Veles, Bitola) by using gamma spectrometry. Data show that, the average value of activity of ^sup 226^Ra and ^sup 232^Th are within the range of (25.58-36.48) and (36.55-50.45) Bq kg^sup -1^, respectively. While, the concentrations of activity of ^sup 40^K in comparison to those obtained for ^sup 232^Th and ^sup 226^Ra are higher in all analyzed soils samples, showing values within the range of (611.59-781.23) Bq kg^sup -1^, the activities of ^sup 137^Cs are generally lower and are within the range of (9.33-18.90) Bq kg^sup -1^, with the highest activity at a depth of 5 cm, which is well in accordance with the data from the literature. The concentrations of these radionuclides are comparable to the available data from the other countries.