ABSTRACT
A systematic radiological survey has been carried out in the region of high-background radiation area in Kollam district of Kerala to define the natural gamma-radiation levels. One hundred and forty seven soil samples from high-background radiation areas and five samples from normal background region were collected as per standard sampling procedures and were analysed for (238)U, (232)Th and (40)K by gamma-ray spectroscopy. External gamma dose rates at all sampling locations were also measured using a survey meter. The activities of (238)U, (232)Th and (40)K was found to vary from 17 to 3081 Bq kg(-1), 54 to 11976 Bq kg(-1) and BDL (67.4 Bq kg(-1)) to 216 Bq kg(-1), respectively, in the study area. Such heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of beach sand soil in the region. Radium equivalent activities were found high in several locations. External gamma dose rates estimated from the levels of radionuclides in soil had a range from 49 to 9244 nGy h(-1). The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples.
Subject(s)
Environmental Monitoring/methods , Potassium Radioisotopes/analysis , Soil Pollutants, Radioactive/analysis , Thorium/analysis , Uranium/analysis , Facility Design and Construction , Gamma Rays , Geography , Housing , Humans , India , Radiation Dosage , Reproducibility of ResultsABSTRACT
Some areas of the world, called high background radiation areas (HBRAs), have anomalously high levels of natural background radiation and the population residing in the areas is exposed to higher levels of radiation doses than other parts of the world where the natural radioactivity contents are normal. In the present investigation, levels of radon, thoron and their progeny are studied in 110 houses in the coastal region of the Kollam district in the state of Kerala, India using the multi-detector twin cup dosimeter. Among these, 10 houses were studied in detail with five dosimeters in each house. Radon activity concentrations were found to vary from 7 to 100 Bqm(-3) and that of thoron from 4 to 66 Bqm(-3) in Neendakara panchayat. In Chavara panchayat, the variations of radon concentrations were from 7 to 83 Bqm(-3) and thoron concentrations were varied from 4 to 86 Bqm(-3). The occurrence of radon and thoron concentrations in the dwellings for both study areas shows that in 50% of the dwellings, the concentration of radon is about 25 Bqm(-3) and in 60% of the dwellings thoron concentration is about 15 Bqm(-3). The ratio of thoron-to-radon concentrations in the dwellings showed a mean value 0.55 (GM=0.45) for the region.
Subject(s)
Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Radiation Monitoring , Radiometry , Radon/analysis , Background Radiation , Housing , Humans , India , Radiation DosageABSTRACT
Urinary stones resected from urinary bladders of patients hailing from Kollam district of Kerala State, India were analyzed by SEM, XRD and by thermal analysis techniques. The analytical results indicate that, stones have different composition, i.e., calcium phosphate, calcium phosphate hydroxide and sodium calcium carbonate. Infrared spectral studies also reveal the presence of phosphates or carbonates in these samples. Further, IR spectral investigations have revealed that amorphous carbonated species are occupied in PO(4) sites in calcium phosphate type stone and OH sites in calcium phosphate hydroxide sample. Thermal studies of these samples also reveal that, carbon dioxide is released from carbonated samples upon heating which is related to amount of carbon content and bond strength. Crystals with defects and irregular morphology are grown inside the urinary bladder due to variation in crystal growth conditions.
Subject(s)
Spectroscopy, Fourier Transform Infrared/methods , Urinary Calculi/chemistry , Calcium Phosphates/analysis , Crystallization , Humans , Hydroxides/analysis , India , Microscopy, Electron, Scanning/methods , X-Ray DiffractionABSTRACT
A spectroscopic study of the Ga-Hg excimer has been carried out for the first time. The vapor mixture excited by a RF discharge shows emission bands with an intensity maximum at 5020 Å. The density of Hg in this study was in the range of 10(18)-10(19) atoms/cc and that of Ga about 10(11) atoms/cc. High-resolution spectra with a dispersion of 1.2 Å/mm were obtained, and vibrational structures were resolved and analyzed on the basis of a triatomic species HgGa(2). Copyright 2001 Academic Press.
