Radon-222 in energy efficient buildings.

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. Integrated measurements under typical living conditions and various climatic conditions are needed to determine average exposures of building occupants.