Radon Measurements in Austrian Buildings and Estimation of Collective Doses for the Population. Final Report for the Period March 1984-March 1987.

摘要

Nuclear track etch detectors were used for the determination of radon and radon daughter levels in Austrian dwelling houses. A diffusion chamber, developed at Karlsruhe, FRG, was used to construct a passive radon detector. It consists of a plastic beaker covered with a glass fiber filter. It is shielded by a cover which has openings on the side so that air can diffuse through and on the top there is a mounted thermoluminescent detector card. The TLD dosimeter was used to determine beta and gamma radiation levels. A polycarbonate foil was placed at the bottom of the diffusion chamber which served as a detector for the alphas emitted by radon daughters. The dosimeters were exposed for a period of three months. The mean concentration of radon in all rooms in dwelling houses in Austria were clearly higher in winter than in summer time. This was interpreted as the effect of reduced ventilation rates in winter time. This effect of ventilation on radon concentration is more significant in living and sleeping rooms than in the cellar. Compared to all rooms in a dwelling house the level of radon concentration was distinctly higher in the cellar. Higher values of radon concentration were found in famous radon spa of Gastein and in the Waldviertel and in a landscape near the Czechoslovakian border. In Vienna a mean value for radon concentration in the living and sleeping rooms was found to be 47 bq/m/sup 3/ which corresponds to an estimated effective dose equivalent to the lung of 10.7 mSv per annum. The whole body effective dose equivalent was estimated to be 1.27 mSv per annum. These estimations were based on the radon equilibrium factor of 0.5. The exposure to radon at such concentration is estimated to cause 3-4% incidence of excess lung cancer in Vienna within the next 20 years. (Abstract Truncated). (Atomindex citation 19:092599)