Radiochemical Characterization of Algae Products Commercialized for Human Consumption

Natural radionuclides and Cs were determined by alpha (U, U, Th,Po,Th, and Th) and gamma spectrometry (Cs, K, Ra, Pb, and Ra via Ac) in 14 dried seaweeds commercialized for human nutrition in Italy. The study was carried out in order to provide information on the concentrations of natural and artificial radionuclides. Cesium-137 (Cs) concentrations in all analyzed samples were always <2.0 Bq kg (dry weight), while the naturally occurring radionuclide concentrations were detectable in all the samples and significantly different in the analyzed seaweeds. Potassium-40 (K) showed a mean activity of 894 Bq kg with a range of 14.1-3,256 Bq kg. The mean of activity for Po was 5.1 Bq kg with a range of 1.5-13.6 Bq kg. The mean of activity for Pb was 8.9 Bq kg with a range of 2.9-25.7 Bq kg. The mean of U and Ra activity concentration was 4.7 and 8.4 Bq kg with a range of 0.1-27.7 and 3.2-24.6 Bq kg, respectively. The mean activity concentrations for Th, Th, and Ra were 0.69, 3.0, and 6.6 Bq kg with ranges of 0.05-3.39, 0.24-15.7, and 0.5-35.6 Bq kg, respectively. Radionuclide activity concentrations were within ranges reported in the scientific literature. The committed effective dose due to all the radionuclides analyzed, from ingestion of 1 kg y of seaweeds, accounts for 0.66% of the natural radiation exposure in Italy.