An overview of the environmental radon problem is presented, with special emphasis on risk estimation and its attendant uncertainties. Although remediation of radon in an individual house is usually fairly inexpensive, aggregate costs can vary greatly, depending on how many houses are deemed hazardous to health. Picking a danger level in the presence of large uncertainties (approximately an order of magnitude separates the high and low value) is a difficult regulatory decision.
"Radon As an Indoor Air Pollutant." Statist. Sci. 3 (3) 371 - 373, August, 1988. https://doi.org/10.1214/ss/1177012840