Natural radioactivity distribution and gamma radiation exposure of beach sands close to Maronia and Samothraki plutons, NE Greece

This study aims to evaluate the activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, ²²⁸Th and ⁴⁰K along the beaches of Maronia and Samothraki being adjacent to the local granitoids. These range from 14-75, 17.5-114.8, 23.7-71.9, 24.5-71.6 and 262-1319 Bq/kg, respectively. The (wt.%) of heavy magnetic (HM) (amphibole, epidote, clinopyroxene, chlorite, magnetite and ilmenite) fraction, the heavy non-magnetic (HNM) (zircon and titanite) fraction, and the total heavy fraction (TH), were correlated with the concentrations of the measured radionuclides in the bulk samples. The measured radionuclides in the beach sands were normalized to the respective values measured in the granitic rocks, which are their most probable parental rocks, so as to provide data upon their enrichment or depletion. The annual effective dose varies between 0.004 and 0.013 mSv y^-1 for tourists and from 0.016 to 0.056 mSv y^-1 for local people working on the beach.