radon

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.

Briefly reviews sources and types of air contaminants common in tight houses. Covers four indoor pollutants - carbon-monoxide and nitrogen dioxide from gas stoves, particleboard plywood and urea-formaldehyde from insulation, and radon from various building materials.Suggests ways of lowering pollutant levels without compromising energy conservation considerations.

The radon contents in the two wings of a university building in Tampere were measured. Outside air was supplied to the corridors where it flowed to the rooms via ceiling ducts. Lower radon values were obtained in the rooms located close to the air supply end of the corridor. Radon content was also higher on the first floor then on higher floors, probably because of radon emission from the gravel layer in the foundation. Notes that the main source of radon in a wooden building is the ground, and the tightness of the floor construction is therefore very important.

Reviews factors affecting indoor air quality, including the effect of mildew, high concentrations of microorganisms, radon, light air ions and chemical pollutants(especially formaldehyde). These are mentioned especially inconjunction with airtight residential buildings in Sweden. Current building standards in Sweden concerning materials, airtightness, air quality and energy conservation are also reviewed, along with areas of current and proposed research in air quality.

Notes that number of houses with radon content exceeding 400 Bq/m*3 is probably far in excess of original estimates. States requirements for new built houses and permitted levels in existing housing. Improved ventilation can reduce risks arising from use of certain building materials now prohibited. Gives details of loans available to combat problem and refers to publication issued by Institute for Radiation Protection on how to assess risk from natural sources and building materials.