Radon concentrations were measured in about 1000 Dutch dwellings and at 200 outside locations using passive monitors. A median concentration of 24 Bq/m3 was found for the dwellings with a highest value of 190 Bq/m3. Seasonal effects were found to be small. Correlations were observed between median radon concentrations and construction parameters including ventilation rate. The concentrations outside show an unexpected dependence on the location. Comparison with previous grab-sampling data on radon-daughter concentrations reveals an average equilibrium factor of 0.3.
Three different investigations of radon in Swedish dwellings are presented - a nationwide study conducted primarily to determine the collective dose to the Swedish population from exposure to radon and radon daughter, a supplementary study of newly built detached houses in order to find out whether theregulations in the Building Code prescribes acceptable radon levels in new houses built on normal ground, and measurements made by the local authorities in order to find houses with levels of radon daughters above the norm.
Describes the different types of monitoring and sampling techniques that can determine the radiation burden of the general public from radon and its decay products. This is accomplished by measuring the range and distribution of radon and rad
The results of our investigations in the Federal Republic of Germany on the Rn-222 and Rn-220 daughter product concentration in dwellings and in the open air are presented. The median Rn-222 concentration indoors was approximately 4 times hig
In Sweden there are two major sources to indoor radon, the building material and radon from uranium rich soils. It is now widely accepted that indoor radon daughter concentration in Sweden, higher than 1000 Bq/m3 is most frequently caused by
In large areas of the Swiss Alps, the high radium content of rocks and soil, which results in high source terms for radon from the ground, may produce considerable indoor levels of radon in dwellings with low air infiltration. During the winter
Sets out the results of research into ventilation and radioactive radiation in 20 private dwellings. All the houses had radon daughter contents in excess of 800 Bq/m3. One of the reasons for these high levels is infiltration of radon from the ground. Tests various methods for tracing the points where radon infiltrates into the house, and proposes measures for reducing the concentration of radon daughter products in the indoor air.
Lists three factors causing a high radon and radon daughter concentration in Swedish dwellings:< 1. By energy-saving measures the ventilation rate has become low.< 2. 10% of existing houses are built of light-weight concrete with a high proportion of radium.< 3. Large regions have high radium content in the ground.< Describes a method for detecting high radon daughter levels by measuring gamma radiation from the outside.
Discusses relatively simple and inexpensive method for ventilating house foundations to reduce radon based on results of a trial on detached housing in Sweden. Principle is to extract radon gas from the ground before it enters living accomodation. Table shows radon daughter intensity before and after corrective measures.
Lists sources of radon and its isotopes in housing. Diagrams illustrate radon content as a function of air change rate. Estimates risk factors. Notes lack of coordinated national or international regulations. Relates number of lung cancer cases caused by radon to total recorded. States recommended maximum permissible concentrations.
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