RESUMEN
Soil samples from Montenegro were analysed by the HPGe detector with 40 % of relative efficiency, for radioactivity due to (226)Ra, (232)Th and (40)K. The average activity concentrations have been found to be 39.9, 43.5 and 437.6 Bq kg(-1), respectively, i.e. in accordance with those in the other South European countries. In order to evaluate the health hazard, radium equivalent activity, absorbed dose rate, annual effective dose rate, external hazard index, annual gonadal dose equivalent and excess lifetime cancer risk (CR) have been calculated. The excess lifetime CR (× 10(-3)) had a range from 0.12 to 0.79, with an arithmetic mean of 0.27, which is in accordance with the global average. Mean gonadal dose equivalent was higher than the world average, and one location was found with the radium equivalent activity >370 Bq kg(-1), i.e. with the external hazard index higher than unity, which means the radiation hazard is not negligible.
Asunto(s)
Radiación de Fondo , Monitoreo de Radiación , Contaminantes Radiactivos del Suelo/análisis , Humanos , Montenegro , Radioisótopos de Potasio/análisis , Radio (Elemento)/análisis , Torio/análisisRESUMEN
(226)Ra activity in the South Adriatic Sea-water, surface sediment, mud with detritus, seagrass (Posidonia oceanica) samples and the mullet (Mugilidae) species Liza aurata, as well as soil and sand from the Montenegrin Coast-was measured using the six-crystal gamma-coincidence spectrometer PRIPYAT-2M. The results are used for calculation of the absorbed (and annual effective) dose rates in air due to the (226)Ra gamma radiation. The absorbed dose rates ranged from 5.94 to 97.16 nGy h(-1) (soil) and from 0.65 to 7.65 nGy h(-1) (sand). In seawater (226)Ra activity is found to be from 0.08 to 0.15 Bq l(-1), while in whole L. aurata individuals from 0.58 to 1.97 Bq kg(-1). Annual intake of (226)Ra by human consumers of this fish species has been estimated to provide an effective dose of 0.006 mSv y(-1).
Asunto(s)
Radiometría/métodos , Radio (Elemento)/análisis , Absorción , Animales , Rayos gamma , Montenegro , Poaceae , Dosis de Radiación , Radioisótopos/análisis , Smegmamorpha , Suelo , Espectrometría gamma/métodos , Agua/químicaRESUMEN
The method is based on coincidence counting of the 609 keV photons from two-, three- and four-step cascade transitions which follow beta(-)-decay of (214)Bi, developed on the six-crystal spectrometer PRIPYAT-2M. As regards the determination of the activity of (226)Ra and its decay products, the double coincidences mode of counting is the optimum one because of the highest spectrometer sensitivity. Minimum detectable radium activity concentration in that mode of counting in a soil sample is estimated to be 0.68 Bq kg(-1) for live measuring time of 897.4s, while it was 2.03 Bq kg(-1) over 10 002.9s in the case of the HPGe spectrometer. Using the double coincidences method, the (226)Ra activity was determined in soil and sand samples from the Coastal region of Montenegro. The measurements were performed much faster than when an HPGe spectrometer is used, and the results showed relatively low level of the radium activity concentration.
Asunto(s)
Monitoreo de Radiación/métodos , Radio (Elemento)/análisis , Contaminantes Radiactivos del Suelo/análisis , Suelo/análisis , Espectrometría gamma/instrumentaciónRESUMEN
The method for activity measurements of the (232)Th daughters, developed at the six-crystal gamma-ray coincidence spectrometer PRIPYAT-2M and based on coincidence counting of the 583 and 2615 keV photons from cascade transitions which follow beta(-)-decay of (208)Tl, as well as on counting the 911 keV photons which follow beta(-)-decay of (228)Ac in the integral and non-coincidence mode of counting, is presented.
Asunto(s)
Espectrometría gamma/métodos , Torio/análisis , Actinio , Espectrometría gamma/instrumentaciónRESUMEN
Indoor radon was systematically surveyed in the town of Niksic-the second largest town in Montenegro-which has some of its settlements built above red bauxite deposits. The radon concentrations were measured in 55 homes in 2002/03, in the summer and winter period, using CR-39 etched track detectors. The average annual radon concentrations were found to be lognormally distributed (geometric mean = 66.2 Bq m(-3), geometric standard deviation = 3.0) within the range from 10 to 966 Bq m(-3), with arithmetic mean of 122.7 Bq m(-3) and median of 61.7 Bq m(-3). Although the annual mean radon concentrations above the action level of 400 Bq m(-3) are found only in four dwellings, the indoor radon levels in the town of Niksic are relatively high when compared with the average in the South European countries, as well as with indoor radon levels in other regions in Montenegro.