1998 National Academy of Sciences- Biological Effects of Ionizing Radiation (BEIR) VI Report: The Health Effects of Exposure to Indoor Radon
Radon is one of the most extensively investigated human carcinogens. On the basis of the epidemiologic evidence from miners and understanding of the genomic damage caused by alpha particles, the committee concluded that exposure to radon in homes is expected to be a cause of lung cancer in the general population.
According to the committee's two preferred risk models, the number of lung-cancer cases due to residential radon exposure in the United States was projected to be 15,400 (exposure-age-duration model) or 21,800 (exposure-age-concentration model). Although these represent the best estimates that can be made at this time, the committee's uncertainty analyses using the constant relative risk model suggested that the number of cases could range from about 3,000 to 32,000. (The 95% upper confidence limit for the exposure-age-concentration model was approximately 38,000, but such an upper limit was highly unlikely given the uncertainty distributions.) Nonetheless, this indicates a public-health problem and makes indoor radon the second leading cause of lung cancer after cigarette smoking.
Click link to view entire study: http://www.epa.gov/iaq/radon/beirvi1.html