Natural radioactivity of fresh waters in Serbia

Statistical tests were performed on the gamma-spectrometry measurement data obtained during the last decade for the natural radionuclides K-40, Ra-226 and Th-232, in water samples collected from the Danube River, the Sava River and its tributaries, ground waters and artificial lakes. The lognormal radiopotassium distribution indicates a single statistical population. The presence of break points in the frequency distribution plots indicates that data for Ra-226 and Th-232 do not come from a single statistical population. The annual ingestion of K-40, Ra-226 and Th-232 was calculated and expressed in Bq y(-1)