Natural radionuclides in sediments and rocks from Adriatic Sea

During the International Scientific Cruise to Adriatic and Ionian Seas organised by the International Atomic Energy Agency, sediment and rock samples were collected. Sediments were sampled with grab corer at six locations in the Southeast Adriatic Sea. Rocks were collected on three islets in the Adriatic Sea. In the samples, natural radionuclides U-238, U-234, Th-232, Th-230, Ra-226 and Pb-210 were determined. After sampling and sample preparation, radiochemical separation procedures were applied. Then the samples were measured by alpha spectrometry system equipped with passivated implanted planar silicon detectors or by low background gas-flow proportional counter. Activity concentrations of natural radionuclides in samples were from 6.2 to 27.0 Bq/kg for U-238, from 7.9 to 28.1 Bq/kg for U-234, from 1.6 to 31.9 Bq/kg for Th-232, from 9.7 to 42.0 Bq/kg for Th-230, from 8.3 to 45.7 Bq/kg for Ra-226 and from 3.0 to 113.4 for Pb-210. The obtained values are discussed in detail and compared with results of similar investigations carried out elsewhere.