نتایج جستجو برای: 222rn
تعداد نتایج: 370 فیلتر نتایج به سال:
Although occupational epidemiological studies and animal experimentation provide strong evidence that radon-222 (222Rn) progeny exposure causes lung cancer, residential epidemiological studies have not confirmed this association. Past residential epidemiological studies have yielded contradictory findings. Exposure misclassification has seriously compromised the ability of these studies to dete...
Measurements have been made of 222Rn release from diverse soils in the region surrounding Málaga, Spain. These flux measurements were carried out by two methods. A direct method using a static chamber technique and another indirect method obtained from concentration profile measurements of 222Rn in the soil air. The effects of meteorological variables and other parameters on 222Rn flux were stu...
In this study 222Rn (Radon) measurement were performed in water and soil gas and also both 222Rn and 220Rn concentrations were determined in air of Mansa and Muktsar district of Punjab, India. The data then used for calculation of the annual effective dose for health risk assessment of public. Totally 35 locations have been selected for the measurements. All measurements (222Rn and 220Rn) were ...
Radon (222Rn) and its decay products are the major sources of natural radiation exposure to general population. The activity concentrations of unattached and attached short-lived 222Rn and thoron (220Rn) progeny in indoor environment of some dwellings of the Jalandhar and Kapurthala districts of Punjab had been calculated using the deposition-based progeny sensors (DRPS/DTPS) and wire-mesh-capp...
Parallel monitoring of 222Rn and its short-lived progeny (218Po and 214Pb) were carried out from November 2007 to April 2008 close to the top of the Schauinsland mountain, partly covered with forest, in South-West Germany. Samples were aspired from the same location at 2.5 m above ground level. We measured 222Rn with a dual flow loop, two-filter detector and its short-lived progeny with a one-f...
The sensitivities (in m) of bare LR115 detectors and detectors in diffusion chambers to 222Rn and 220Rn chains are calculated by the Monte Carlo method. The partial sensitivities of bare detectors to the 222Rn chain are larger than those to the 220Rn chain, which is due to the higher energies of alpha particles in the 220Rn chain and the upper energy limit for detection for the LR115 detector. ...
The emanating power of radon provides information on the internal structure of a mineral and the radiation damage caused by the decay of 238U, 235U and 232Th (and their daughters) that are present in the mineral. The concentration of 222Rn in groundwater is primarily controlled by the concentration of U and Th in the underlying rocks, as well as the emanation coefficient for that particular roc...
The activity concentrations of 228Ra, 226Ra and 222Rn have been analysed in 452 drinking water supplies of São Paulo State. This study started in 1994 and covered 54% of the 574 existing counties. Concentrations up to 235 and 131 mBq l-1 were observed for 226Ra and 228Ra, respectively, whereas 222Rn concentrations reached 315 Bq l-1. Radiation doses up to 0.3, 0.6 and 3.2 mSv yr-1 were estimate...
As part of an international 222Rn measurement intercomparison conducted at Bermuda in October 1991, NIST provided standardized sample additions of known, but undisclosed ("blind") 222Rn concentrations that could be related to U.S. national standards. The standardized sample additions were obtained with a calibrated 226Ra source and a specially-designed manifold used to obtain well-known dilutio...
A procedure for the calibration of instruments for the detection of 222Rn in air is described. The method is based on the alpha-spectrometric determination of the concentration in air of 218Po in the calibration chamber. The calibration chamber is described, together with the method of maintaining a high aerosol concentration. The 218Po concentration at steady state in the chamber is found to b...
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