An assessment of the external radiological impact in areas of Greece with elevated natural radioactivity

In the present study, the radiological impact assessment in three selected areas of elevated natural radioactivity in Greece is attempted, based on measurements, theoretical relations, and simple model application. These areas are Milos--an island of volcanic origin in Cyclades Archipelago, Ikaria--an island in the Eastern Aegean Sea and Loutraki--a coastal area in mainland Greece. These areas are characterized by their geothermal springs and vents, which emit fluids into the littoral and sublittoral zones. The results include: (a) the exposure dose rates assessed by a car-borne scintillation spectrometry system; (b) laboratory measurements of the activity concentrations of the gamma-emitters of 238U and 232Th series and 40K in soil, spring water, seawater and sediments by gamma-spectrometry; (c) estimations of the effective dose rate equivalents and health risk assessment for humans and external dose rates for natural aquatic populations in relation to organism habitat; and (d) a radiological evaluation for the environmental quality, in terms of the discrete zones of impact of ionizing radiation.