Radon daughters measurements

Together with the radon daughter measurements, nearly continuous measurements of the ventilation rate are performed by means of the release of N2O tracer gas and observation of its decay with an infrared spectrometer (Miran 101). Furthermore the aerosol concentration and size distribution are monitored every 20 to 30 min with an automated aerosol spectrometer (Raes et al.,1984). 

C is the average monthly morning radon concentration in pCi./cu. meter computed from radon daughter measurements, S is the stability in °F./27 meters, and TMD is the total moisture detention in mm. The constants k and k and the correlation coefficients for the equations were obtained for all three variables and also separately for C vs. stability and C vs. TMD. 

That the R2 value for the 12-hour period is largest suggests that radon-daughter measurements were affected more by the accumulation of radon near ground level during the entire night than by the accumulation of the short lived radon daughters in air immediately before collection. 

Philips, C.R., Pai, H.E. (1976). Environmental radon and radon daughter measurements in Port Hope. Report to the Atomic Energy Control Board of Canada (as cited in Van der Vooren et al., 1982). 

Wolfs, F., Hofstede, H., deMeijer, R.J. and Put, L.W., Measurements of radon-daughter concentrations in and around dwellings in the northern part of the Netherlands a search for the influences of building materials costruction and ventilation. Health Phys, 47 ... 

Indoor air radon concentrations measured in a randomly selected sample of 220 Irish houses have been found to range from about 20 Bq/nr to as high as 1740 Bq/nr with a median value of 61 Bq/nr. Using current dose estimation methods the estimated effective dose equivalents due to radon daughter inhalation in these houses are 1.6 mSv/year (median value) and 46 mSv/year (maximum value). 

Integrating alpha track based passive detectors, which yield both a measurement of the mean radon concentration and of the radon daughter equilibrium (F) in each house, are being used in this national survey. 

Put, L.W. and de Meijer, R.J., Measurements of Time-averaged Radon Daughter Concentrations with Passive Dosemeters. Sci. Total. Environ. 45 389-395 (1985). 

Up to the present, there has been no systematic study of radon or radon daughters in Japanese homes. We have, therefore, measured the distribution of radon concentrations in houses to determine the factors that influence them in Japan. For this end, long-term measurements of radon concentrations in the home environment were undertaken as a joint-study of five reserch institutions. These preliminary observations are for 5 areas of Japan for which results are available. 

Measurements were made using two types of passive track-etch alpha dosimeters. One of them was the bare detector of CR-39. After exposure these dosimeters were etched by 30 % NaOH at 70°C for 5 hours. The number of pits was scored under a microscope with a television camera in Shiga University of Medical Science. Methods of calibration and adjustment for deposition of radon daughters introduced by Yonehara (Yonehara et al., 1986) were adopted. The second detectors were Terradex type SF (Alter and Price, 1972). These detectors consist of a plastic cup, covered by a filter to allow entry only of gases, with a track-etch detector inside. The reading of results was carried out by Terradex Corp. in Walnut Creek, California, U.S.A.. The measurements of radon concentration were carried out by both methods in each location, except for Hokkaido where the measurements were done only by Terradex. However, the data obtained by CR-39 detectors will be mainly presented in this paper, because the two methods did not give identical results as separately reported in this proceedings by Yonehara et al. (Yonehara et al., 1986). 

Shimo, M., A Continuous Measuring Apparatus using Filter-Sampling Technique for Environmental Radon Daughters, Research Letters on Atmospheric Electricity, 4 63-70 (9184). 

Fleischer, R.L., Theory of Passive Measurement of Radon Daughter and Working Levels by the Nuclear Track Technique, Health Physics 47 263-270 (1984). 

Rock, R.L., D.B. Lovett, and S.C. Nelson, Radon-daughter Exposure Measurement with Track Etch Films, Health Physics 16 617-621 (1969). 

Scott, A.G., Radon Daughter Deposition Velocities Estimated from Field Measurements, Health Physics 45 481-485 (1983). 

Radon concentrations were measured by use of calibrated Lucas scintillation flasks, while radon and thoron daughters and the resulting potential alpha energy concentration (PAECj were determined using filter samples (Thomas, 1972) and a continuous electrostatic precipitator (Andrews et al., 1984). The radon daughter positive... 

George, A.C., M.H. Wilkening, E.O. Knutson, D. Sinclair, and L. Andrews, Measurements of Radon and Radon Daughter Aerosols in Socorro, New Mexico, Aerosol Sci. and Tech. 3 277-281 (1984). 

NCRP, Report 78. Evaluation of Occupational and Environmental Exposures to Radon and Radon Daughters in the United States. National Council on Radiation Protection and Measurements, Bethesda, Md. 

Thomas, J.W., Measurements of Radon Daughters in Air, Health Phvs. 23 783-789 (1972). 

The paper summerizes the experimental data on the equilibrium factor, F, the free fraction, fp, the attachment rate to the room air aerosol, X, the recoil factor,, and the plateout rates of the free, qf, and the attached, q3, radon daughters, determined in eight rooms of different houses. In each room several measurements were carried out at different times, with different aerosol sources (cigarette smoke, stove heating etc.) and under low (v<0.3 It1) and moderate (0.3[Pg.288]

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