Levels of Outdoor Gamma Dose Rates in Selected Sites from Romania, Moldova and Greece

Abstract

The study presents a synthesis of results obtained in the frame of international cross-border projects, implemented in partnership, for gamma radiation dose rates measured in outdoor environments in various sites in Romania, Moldova, Greece, including urban, rural, touristic and protection areas. The selected sites (n=41) are found in the Eastern Carpathians Mountains, Lower Danube basin, Danube Delta, Lower Prut River Reserve, Dniester River, as well as Black Sea and Northern Aegean Sea basins. The data recorded for targeted spots using portable dosimeters highlight an hourly and daily variation of the outdoor gamma dose rate and the specificity of the geological background and terrain utilization. The mean values of outdoor gamma radiation dose rate, calculated for 50 measurements per each site, are ranging between 71 nGy/h (Vama Veche, Constanta County, Black Sea coast, Romania) and 394 nGy/h (Nea Peramos, Ammolofoi beach, Northern Aegean Sea, Greece), with a minimum of 41 nGy/h in Vama Veche and a maximum of 489 nGy/h in Ammolofoi beach. A comparison is made with legislated values and other world places. The measurements performed at water surface during boat expeditions (n=21) on Danube River and Danube Delta lakes and channels point out lower values of dose rate, due to the weak influence of gamma rays’ emission from bottom sediments. The data of the dose rate temporal variations will be used for the target regions as a base in further investigations and preparation of maps of gamma dose rates (terrestrial and cosmic), and calculation of the health risk for inhabitants and tourists.