Ventilation measurements in new Swedish houses show that they seldom fulfill minimum requirements of 0.5 air changes per. hour applicable to specific housing classifications. Basic natural ventilation is often used. Discusses consequent problems including condensation and humidity, excess radon daughters and formaldehyde content in the room air. Notes future demands for systems to include heat exchangers.
The daughter products of radon are chemically active materials which, when inhaled are very likely to deposit in the respiratory tract. Defines a special unit, the working level, to indicate the radiation burden from radon daughters. Reports study of exhalation rates from various building materials made by enclosing samples in containers and analysing air samples from the containers. Gives table of results. Discusses control of airborne radiation by increasing the ventilation rate, sealing room surfaces, mechanical circulation and filtration of the air.
Data has been obtained on the radon concentration in natural gas supplied to several metropolitan areas in the United States. The average value of 20pCi/l was selected to estimate the contribution of this source of natural radioactivity to doses from radon daughters received by individuals in homes. Radon daughter concentrations in the home atmosphere were calculated by use of computer programs for an 800 cu.ft. house in which 27 cu.ft. of gas per day was used for cooking in an unvented kitchen range.
Gives details of a method for determining the amount of radon emanating from a carbonate rock specimen. Analysis was first made with rock in solid form. An essay was then made with the material containing radium in a clear acid solution.< Discusses the need for the analysis of building material causing any type of abnormally high background variation. Outlines laws covering the buildup and decay of radon.
Describes sources of radon in materials and measures of exposure. Reviews measurements of radon in mines and dwellings. Describes measurements of the concentration of radon in a sealed chamber. Concludes that concentration of radon daughters can be reduced by removing dust from the air using an electrostatic precipitator or by using a very high ventilation rate combined with an efficient heat exchanger. Finds most significant sources of radon in dwellings are cracks and openings in the floor. Suggests reducing radon by covering bare surfaces and sealing the floor, or using a crawl space.
Reports a series of experiments made in the U.S. Bureau of Mines radon test chamber to study the effects of condensation nuclei, humidity and turbulence on the rapid deposition or plateout of radon daughter activity on the chamber walls. Under low humidity conditions the presence of a small fan reduced the working level by 41%. The activity was not deposited on the walls by the turbulent flow from the fan but actually became attached to the fan blades. High relative humidity (>80%) totally inhibited this observed effect.
Reviews methods for the measurement of the activity concentrations of radon-222 daughters in air. Describes method which enables activity concentrations as low as 0.05 pc i/l of ra a to be measured with simple readily transportable equipment. The method presented here also measures RaB (214 Pb) and RaC (214Bi) activity concentrations and working levels with improved precision compared with established methods.
Gives general discussion of sources of radon gas and its daughter products. Reviews measurements made of radon concentrations in air. Outlines control strategies for limiting radon in buildings.
A portable background gamma-radiation dosimeter with a high-pressure ionization chamber was designed. The gamma background radiation dose rate and radon concentration in the air of the 97 new flats were measured. The flats were selected in the houses of the experimental settlement in Suzewiec (quarter of Warsaw), of three settlements of Kodz, and of five settlements of the upper silesian industrial area. For the construction of these settlements building materials typical for new constructions in Poland were used, such as products derived from metallurgical wastes like slag or boiler ash.
Reports measurements of concentrations of thorium, potassium, uranium radium, and relative radioactivity of building materials used in the United Kingdom. Gives table of results. Examines in particular calcined gypsum prepared as a by product in the manufacture of superphosphate fertilizers. Discusses the relationship between radium concentration and gamma-ray dose rate
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