Radon and lung cancer: Protocol and procedures of the multicentre studies in the Ardennes-Eifel region, Brittany and the Massif Central region

The results of the small case-control studies performed in a number of countries prove the feasibility of this type of technique in qualifying the risk of indoor radon. However, as the final purpose is the quantification of this risk, a study on a much larger scale is necessary to arrive at results with enough statistical significance and power. Therefore, as part of a European coordinated project, the Ardennes-Eifel study was set up. In this project the study area coincides more or less with a geological zone, situated partly in France, Belgium, Luxemburg and Germany. In a first phase a common protocol was worked out, dealing with general items as the selection of cases and (hospital/community) controls the residential criteria for inclusion in the study and the specifications of the radon measurements. Much attention was given to the disease for the hospital controls and a list of ineligible diseases most strongly related to tobacco was agreed upon. A common core questionnaire is used, including items such as residential history since birth, occupational history, exposure to passive smoke (for non-smokers and occasional smokers) and educational attainment of the partner. Each country is also free to include additional items of its own. In France, this case-control study is extended to the granitic region of Brittany and in a second period to the region of Massif Central. In these studies as well as in the national German study on radon and lung cancer, a protocol in all points comparable to that of the Ardennes study is used.