radon

Discusses radon risks in housing and carcinogenic effects. Compares background radiation as part of our natural environment and the effects of radon gas on building materials. Notes effects of reduced ventilation designed to reduce energy consumption and its influence on the frequency of cancer.

Describes a mathematical model for the calculation of the expected values of radon and radon daughter concentrations in indoor air. Presupposes that it is possible to obtain or measure the parameters necessary for the calculation eg the radon emanation of the building material, the radon content of the soil air, and the leakage of air from the soil into the building. Research in these areas is in progress both in Sweden and abroad.

Tests a method which determines the infiltration of air and radon from the soil to a building. Makes measurements of total air flow along with usual airtightness tests. Describes practical tests in a detached house with a raft foundation on a gravel esker, and determines the permeability curves for thewhole house and the raft alone, and also the permeability of the soil to air. Describes the way the results are used for determination of air infiltration in different climatic conditions, and tests different radon reducing methodsusing the previously developed system analysis.

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.

Presents the contents of a memorandum of evidence to the Royal Commission of Environmental Pollution. Treats exposure of the community to radiation caused by radon decay products in indoor air, which contributes about a third of the overall effective dose equivalent received annually by an average person in the UK. Treats surveys to improve the estimate of indoor exposure. Discusses the possibility of a radon limitation scheme.

States that as many as 600 lung cancers a year may be attributable to radon gas, and this may jump to as many as 1500 if energy conservation measures reducing draughts become more widespread. Notes that radon appears to be present in every hou

Reports on radon measurements made in the municipalities of Uppsala, Sodertalje and Tyreso. Uses about 7600 kodak plastic films in private houses and bloks of flats. About 3-14% of private residences have concentrations above 200 Bq/m3, and 0.5% blocks of flats. 8-68% of private residences and 57-83% of blocks of flats have less than 70 Bq/m3 of radon.

Performs an investigation concerning the operation of ventilation systems in an old building (a museum) after extensive repairs have been made. The new ventilation system is a supply and exhaust type. Measures ventilation rate and energy consumption for 1. mechanical air supply and and exhaust 2. Mechanical exhaust only 3. Exhaust from the secondary space only with other ventilation ducts closed. Uses nitrous oxide as tracer gas. Measurement of radon concentration shows that concentration is lower in 1 than 2, in spite of the fact that the air change rate is the same in both (0.7 ach).

Reports a survey on both solar and conventional homes in north-eastern New York State. Finds that houses which are more airtight have 3 times the radon levels of conventional houses. The highest 2 levels of radon in the solar homes give doses over 30 yrs that are known to produce lung cancer in 1% of uranium miners. Summer readings in more than one half of the cases are different from winter ones by a factor of 2 or more, so that year-round measurements are necessary for precise dosimetry. The track etching technique is ideally suited for such measurements.