ABSTRACT
The natural radioactivity and the associated radiation hazards of soils from the Cumanayagua Granitoide-Granitic massif in the central south of Cuba have been studied. Mass activities of the natural radionuclides 238U, 232Th and 40K varied in the ranges 10.4-33, 4.6-21.7 and 381-1201 Bq kg-1, respectively. The radium equivalent activity (91.4 ± 22.1 Bq kg-1), absorbed dose rate (45.6 ± 11.1 nGy h-1), annual effective dose rate (56.1 ± 13.7 µSv y-1) and the external hazard index (0.25 ± 0.06) have been calculated and compared with the internationally approved values. According to these results, the area can be regarded as an area with normal natural background radiation and may not pose radiological risks to the inhabitants owing to harmful effects of ionizing radiation from the natural radionuclides in soils. This study provides background radioactivity concentrations in Cumanayagua Granitoide area and generate a baseline data for radiological mapping of Cuba in the future.
Subject(s)
Construction Materials/analysis , Geologic Sediments/analysis , Potassium Radioisotopes/analysis , Silicon Dioxide/chemistry , Soil Pollutants, Radioactive/analysis , Soil/chemistry , Thorium/analysis , Uranium/analysis , Background Radiation , Cuba , Humans , Radiation Dosage , Radiation MonitoringABSTRACT
The radioactivity of NORM was measured in ashes collected from a fuel-oil power plant in Cienfuegos, Cuba, using an HPGe gamma-ray spectrometer. The (226)Ra, (210)Pb, (40)K, (232)Th and (238)U activity concentrations reached 240, 77, 59, 70 and 15 Bq kg(-1), respectively. The potential radiological hazard of these residuals was assessed. The radium equivalent activities of the samples varied from 54 to 345 Bq kg(-1). The gamma index was calculated to be lower than that of the reference values, and the gamma absorbed dose rate was higher than the average reported for the earth's crust; however, the assessed annual effective dose was slightly lower than the annual effective dose limit for public, i.e. 1 mSv. Therefore, these bottom ashes were not dramatically enriched with radionuclides and may be used as an additive for building materials without restrictions from a radiological protection point of view.