Characterization and control of radon-222 and its progeny in buildings.

Indoor exposure to the naturally occurring, short-lived decay products of radon (Rn-222) inside buildings and homes may pose a significant public health problem. Estimates are that as many as 8 million residential buildings may have indoor radon concentrations that exceed the action level recommended by the U.S. Environmental Protection Agency (4 pCi.L-1). This paper examines the sources of radon in buildings and provides an overview of the methods currently available to reduce indoor concentrations of radon and its decay products.