Assessment of gamma radiation exposure of beach sands in highly touristic areas associated with plutonic rocks of the Atticocycladic zone (Greece).
This study aims to evaluate the activity concentrations of238U,226Ra,232Th,228Th and40K along beaches close to the plutonic rocks of the Atticocycladic zone that ranged from 15 to 628, 12-2292, 16-10,143, 14-9953 and 191-1192 Bq/kg respectively. A sample from island of Mykonos contained the highest232Th content measured in sediments of Greece. The heavy magnetic fraction and the heavy non-magnetic fraction as well as the total heavy fraction, were correlated with the concentrations of the measured radionuclides in the bulk samples. The heavy fractions seem to control the activity concentrations of238U and232Th of all the samples, showing some local differences in the main238U and232Th mineral carrier. Similar correlations have been found between238U,232Th content and rare earth elements concentrations. The measured radionuclides in the beach sands were normalized to the respective values measured in the granitic rocks, which at least in most cases are their most probable parental rocks, so as to provide data upon their enrichment or depletion. Since the Greek beaches are among the most popular worldwide the annual effective dose equivalent received due to sand exposure has been estimated and found to vary between 0.002 and 0.379 mSv y-1for tourists and from 0.018 to 3.164 mSv y-1for local people working on the beach. The values corresponding to ordinary sand samples are orders of magnitude lower than the limit of 1 mSv y-1, only in the case of heavy minerals-rich sands the dose could reach or exceed the recommended maximum limit.
Department of Mineralogy, Petrology and Economic Geology, School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece. Electronic address: argpapad@geo.auth.gr.
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Papadopoulos
Department of Mineralogy, Petrology and Economic Geology, School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Koroneos
Department of Mineralogy, Petrology and Economic Geology, School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Christofides
Department of Mineralogy, Petrology and Economic Geology, School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Papadopoulou
School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Tzifas
Laboratory of Nuclear Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Stoulos
D001417:Background Radiation; D005720:Gamma Rays; D006115:Greece; D011197:Potassium Radioisotopes / Q000032:analysis; D000069079:Radiation Exposure; D011834:Radiation Monitoring; D011883:Radium / Q000032:analysis; D012822:Silicon Dioxide / Q000737:chemistry; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D013910:Thorium / Q000032:analysis; D014501:Uranium / Q000032:analysis
D011197:Potassium Radioisotopes; D012990:Soil Pollutants, Radioactive; C007886:granite; D014501:Uranium; D013910:Thorium; D012822:Silicon Dioxide; D011883:Radium
Annual effective dose equivalent; Beach sands; Granitic rocks; Heavy magnetic and non-magnetic fractions; Natural radioactivity