radon

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.

Gives an account of the results of research into ventilation and radiation in buildings, including one-family dwellings and blocks of flats. Investigation includes recording the air change rate, the radon levels, the radium emanation rate and gamma radiation. The object of the investigation is to obtain background material for continued research into limit values for radon and radium emanation levels in dwellings.

Uses "Track Etch" detectors to measure nearly 40000 time-averaged radon concentrations in Canadian, Swedish and US homes. In some areas indoor exposure rates exceed 20 pci/l in as many as 15% of homes surveyed. Such levels may lead to an increased lung cancer risk. The "Track Etch" detectors are based upon a plastic nuclear track detector which undergoes permanent radiation damage when struck by an alpha particle. These small detectors are very convenient to use in occupied homes and buildings.

Discusses common sources of indoor air pollution in buildings and the specific pollutants emitted by each source, including combustion emissions, formaldehyde and other organic substances and radon. Also covers potential health effects and possible control techniques, including dilution by natural or mechanical ventilation.

Describes a study of indoor air quality in 12 retrofitted houses of the Bonneville Power Administration (BPA) Midway Substation Residential Community, undertaken by LBL and BPA. Measures effective leakage areas and average concentrations of nitrogen dioxide, formaldehyde and radon before and after retrofit. Finds average reduction in leakage area of 32%. None of the pollutants measured before or after retrofit reached levels exceeding existing guidelines.

Shows that recent investigation has revealed harmful pollutants in greater concentrations in energy-conserving buildings then in the surrounding outdoor air. Some of the pollutants found include particulate matter, carbon monoxide, formaldehyde, nitrogen dioxide and radioactive radon. In the use of some construction materials, measures intended to reduce energy consumption may contribute to the buildup of indoor air pollution. Reviews characteristics of indoor pollutants and major methods of control.

Describes sources of radon in buildings. Summarizes data on observed indoor radon concentrations in houses in New York, Salzburg Austria, and Florida. LBL studies in energy efficient buildings in Maryland, Minnesota, and New Mexico show that tight houses have higher radon concentrations then conventional houses. The data reported is based on "grab samples" taken on mild days (low wind and small indoor and outdoor temperature differences) with all doors and windows closed, resulting in a "worst case" estimate.