During the past 3 decades, a series of studies have been conducted within the operation of the National Academy of Sciences' National Research Council to evaluate the risks to human health following exposure to ionizing radiations. This series of risk assessments by committees on the Biological Effects of Ionizing Radiations, or BEIR, included a BEIR IV report in 1988 (NRC 1988) which focused on health effects of radon and other alpha-particle emitters.
The context for the work of the 6th Committee on the Biological Effects of Ionizing Radiations (BEIR VI), in the National Research Council's Board on Radiation Effects Research (BRER), has been set by concern about the risk posed to the public by indoor radon. As a basis for developing public policy on indoor radon, the risks associated with indoor radon across the range of residential exposures received by the population must be characterized. That range extends from exposures at the higher end comparable to those received by miners found to be at increased risk lung-cancer for down to exposures at an average indoor concentration of about 50 becquerels/cubic meter, or 50 Bqm-3 (1.4 picocuries/liter, or 1.4 pCiL-1), which are much lower than the exposures of most of the miners included in the epidemiologic studies. The degree of uncertainty in the risk estimates increases from the high end of the exposure range where risks are