^ Department of Experimental Physics, University College Dublin, Dublin 4, IrelandCase-control studies on lung cancer and radon in dwellings have been conducted in North Americaand Europe, including one study in Lazio region, in Central Italy. Great attention is generally devotedto the reduction in the uncertainty in radon exposure assessment because it can give rise to relevantuncertainty in the estimated risk. One of the main potential sources of uncertainty is the use ofcontemporary radon concentration measurements as estimators of past concentration values.
The use of contemporary radon (222Rn) gas concentrations to estimate retrospective radon-relateddoses can introduce substantial uncertainties in epidemiological analyses. These uncertainties tend tobias the results of radon-lung cancer epidemiologic studies towards the null. Temporal variability ofradon progeny over past decades and the variability in the dose effectiveness of airborne radonprogeny caused by indoor atmospheric differences are among the main sources of uncertainties in ourregion.