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Abstract  

Indoor natural radiation dose existing in dwellings of Coonoor have been estimated using thermoluminescent dosimeters. TLDs are displayed in indoors and are replaced after three-month period. The seasonal averages of the dose rate and the annual effective dose equivalent are calculated from the measured results. Geographical and seasonal variations as well as the differences between indoor to outdoor dose rates have also been studied. Very good correlation exists between the indoor dose rates measured by TLD and environmental radiation dosimeter with correlation coefficient of 0.91. The annual effective dose equivalent to the Coonoor population due to indoor gamma radiation was estimated to be 970 mSv/y for the period of 1997–1998.

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Abstract  

Uranium (238U) and thorium (232Th) concentrations were evaluated in different cereal, fruit and vegetable samples by using a method based on the calculation of the detection efficiencies of the emitted a-particles by CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) and measuring the resulting track densities. The influence of the soils on which the plants grow, and the fertilizers used was investigated. Total daily intakes of 238U and 232Th for a typical food basket were estimated to be 1.16 Bq.d-1 and 0.94 Bq.d-1, respectively, corresponding to a total committed effective dose of 0.27.10-7 Sv.d-1. Annual committed effective doses due to 238U and 232Th originated from the ingestion of different foodstuffs were evaluated for the adult members of the population by using the ICRP ingestion dose coefficients.

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Abstract  

The paper presents and discusses radon activity concentrations in Cypriot groundwater systems as a function of the background lithology and seasonal/meteorological conditions using an airborne radon monitoring system (ARM) after separation of radon by out-gassing. Radiometric analysis of groundwater samples obtained from non-contaminated systems showed that radon concentration in groundwaters varies strongly (0.1–10 Bq L−1) depending mainly on the hosting geological matrix but also to lesser degree on atmospheric/meteorological conditions. The associated excess annual dose has been estimated to range between 10−6 and 10−4 mSv y−1, which is an insignificant contribution to the radiation exposure of the Cypriot population caused by airborne radon (0.5 ± 0.4 mSv y−1).

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Journal of Radioanalytical and Nuclear Chemistry
Authors: I. O. Abugassa, S. O. Abugassa, Y. S. Khrbish, A. T. Bashir, K. Doubali, and N. Ben Faid

Summary  

The trace elements composition of gallbladder stones samples of the types cholesterol, pigment and mixed stones in addition to bile have been investigated by k 0-instrumental neutron activation analysis (k 0-INAA). The samples were obtained from several individuals of adult subjects of the Libyan population who undergone open surgery of gallbladder (cholecystectomy) at Al-khadra University Hospital in Tripoli. The samples were lyophilized, irradiated together with Au wire and Zr foil, which serve as flux ratio monitor and a parameter at TNRC. Concentrations of 24 elements in gallstone and 23 elements in bile were determined. The levels of the trace elements in the various samples investigated are measured and discussed. The reliability of the analysis was checked with several biological standard reference materials.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: D. S. Barber, J. D. Betsill, A. H. Mohagheghi, H. D. Passell, B. Yuldashev, U. Salikhbaev, A. Djuraev, I. Vasiliev, and V. Solodukhin

Summary  

This paper presents the results of radioecological investigation of Central Asian rivers.This work was done as part of the Navruz Project, a cooperative, transboundary river monitoring project involving rivers and institutions in Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan, and facilitated by Sandia National Laboratories in the United States. The study of waterborne radionuclides and metals concentrations in Central Asia is of particular interest because of the history of nuclear materials mining, fabrication, transport, and storage there, when it was part of the Soviet Union. This development left a legacy of radionuclides and metals contamination in some Central Asian regions, which poses a clear health hazard to populations who rely heavily upon surface water for agricultural irrigation and direct domestic consumption.

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Abstract  

The building materials and products whose content of natural radionuclides are contributors to the radiation exposure of the population. In this study several types of building materials used for construction of living buildings in Slovakia were examined. The concentrations of natural radionuclides (226Ra,232Th and40K) were determined by -ray spectrometry with an HPGe detector. In the second part of the work, sixty samples of building products (panel), used for dwelling construction in several towns in Slovakia, were analysed. The concentration of natural radionuclides and the radium equivalent activity content in the inner-and outerside of the wall were estimated. The results were used for the calculation of the annual mean effective photon dose rates, by the model and calculation procedure of KRISIUK and KARPOV.

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Abstract  

Studies on natural background radiation show that the major contribution of radiation dose received by population is through inhalation pathway vis-à-vis contribution from radon (222Rn) gas. The immediate parent of radon being radium (226Ra), it is imperative that radium content is measured in the various matrices that are present in the environment. Among the various methods available for the measurement of radium, gamma spectrometry and radiochemical method are the two extensively used measurement methods. In comparison with these two methods, the radon emanometric technique, described here, is a simple and convenient method. The paper gives details of sample processing, radon bubbler, Lucas cell and the methodology used in the emanometric method. Comparison of emanometric method with gamma spectrometry has also undertaken and the results for a few soil samples are given. The results show a fairly good agreement among the two methods.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: J. Planinić, D. Faj, B. Vuković, Z. Faj, V. Radolić, and B. Suveljak

Abstract  

Although studies of radon exposure have established that Rn decay products are a cause of lung cancer among miners, the lung cancer risk to the general population from indoor radon remains unclear and controversial. Our epidemiological investigation of indoor radon influence on lung cancer incidence was carried out for 201 patients from the Osijek town. Ecological method was applied by using the town map with square fields of 1 km2 and the town was divided into 24 fields. Multiple regression study for the lung cancer rate on field, average indoor radon exposure and smoking showed a positive linear double regression for the mentioned variables. Case-control study showed that patients, diseased of lung cancer, dwelt in homes with significantly higher radon concentrations, by comparison to the average indoor radon level of control sample.

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Summary  

It is well known that the interest in radon concentration indoor as a pollutant emerged during the energy crisis of seventies which led to reduce ventilation in dwellings. Recently the Euratom Recommendation 2001/928 suggested the necessity of performing frequent 222Rn checks on tap waters. As a consequence of this Recommendation, Urbino and Perugia Universities carried out a preliminary 222Rn determination on tap waters of the Pesaro-Urbino province. Samplings were carried out in twenty-eight sites and radon concentration was determined by liquid scintillation counting and gamma-spectrometry. The results obtained by the two techniques were comparable (the deviation from the mean is lower than 10% for 54.5% of the samples). The resulted 222Rn concentration was very low (5 Bq . l-1 for 43% of the samples) and, therefore, radon in waters cannot be considered as a direct radiological risk for the local population.

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Acta Chromatographica
Authors: A. Ochoa, J. Fechine, J.C. Escalona, J. García, S.G. dos Santos, and M. Sobral da Silva

Excoecaria lucida Sw. is an evergreen shrub widely distributed in Cuba and throughout the Caribbean region. In spite of its extended traditional use as antiasthmatic and antimicrobial by the local population, scientific reports on the species are almost nonexistent. This paper focuses on the isolation and characterization of compounds present in the crude extract of E. lucida Sw. leaves through the combined use of chromatographic and spectroscopic techniques (medium pressure liquid chromatography, thin-layer chromatography, gas chromatography, nuclear magnetic resonance 1H, and mass spectrometry). A total of 15 nonpolar substances were identified in the four main fractions obtained; some of these substances could be related with the antimicrobial properties attributed to the species.

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