Radon levels in groundwaters and natural radioactivity in soils of the volcanic region of La Garrotxa, Spain.
Groundwater radon level and soil radionuclide concentration have been measured in the volcanic region of La Garrotxa (Catalonia, Spain) to further research on the origin and dynamics of high radon levels over volcanic materials found in this region. Water samples from different aquifers have been collected from wells and springs and the water radon levels obtained have been lower than 30 Bq l(-1). Soil samples have been collected from different geological formations (volcanic and non-volcanic), being Quaternary sedimentary deposits those that have presented the highest mean values of (40)K, (226)Ra and (232)Th concentrations (448 ± 70 Bq kg(-1), 35 ± 5 Bq kg(-1) and 38 ± 5 Bq kg(-1), respectively). Additionally, indoor/outdoor terrestrial radiation absorbed dose rate in air have been measured to better characterize the region from the radiological point of view. Terrestrial radiation absorbed dose rates measurement points have been chosen on the basis of geological and demographical considerations and the results obtained, from 27 to 91 nGy h(-1), show a clear relation with geological formation materials. The highest terrestrial gamma absorbed dose rate is observed over Quaternary sedimentary deposits as well. All these results help to better understand previous surveys related with indoor and outdoor radon levels and to reinforce the hypotheses of a radon transport through the fissure network.
Grup de Física de les Radiacions, Departament de Física, Edifici Cc, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. Electronic address: victoria.moreno@uab.cat.
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Moreno
Unitat de Geodinàmica Externa i d'Hidrogeologia, Departament de Geologia, Edifici Cs, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Bach
Grup de Física de les Radiacions, Departament de Física, Edifici Cc, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Grup de Física de les Radiacions, Departament de Física, Edifici Cc, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis; D005720:Gamma Rays; D019015:Geologic Sediments / Q000737:chemistry; D060587:Groundwater / Q000032:analysis; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011868:Radioisotopes / Q000032:analysis*; D011886:Radon / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013030:Spain; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D000396:Air Pollutants, Radioactive; D011868:Radioisotopes; D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive; D011886:Radon
Gamma radiation; Groundwater; Radionuclide content; Radon; Volcanic materials