A preliminary survey of natural radionuclides in soil and indoor radon in the town of Niš, Serbia

The activity concentration of natural radionuclides in the samples of soil from the town of Nis were measured using the gamma spectroscopy system. The average activities of 226Ra, 232Th and 40K are: 19, 30 and 409 Bq/kg, respectively. The average outdoor absorbed dose rate due to the gamma radiation from the soil is 41 nGy/h, while the corresponding annual effective dose is 0.05 mSv. The measurements of indoor radon concentrations were also done in this study. As an average 222Rn concentration, 61 Bq/m3 was determined, with the corresponding annual effective dose of 2.87 mSv.