Case-control study on lung cancer and residential radon in western Germany

In a 1990-1996 case-control study in western Germany, the authors investiga ted lung cancer risk due to exposure to residential radon. Confirmed lung c ancer cases from hospitals and a random sample of community controls were i nterviewed by trained interviewers regarding different risk factors. For 1 year, alpha track detectors were placed in dwellings to measure radon gas c oncentrations. The evaluation included 1,449 cases and 2,297 controls recru ited from the entire study area and a subsample of 365 cases and 595 contro ls from radon-prone areas of the basic study region. Rate ratios were estim ated by using conditional logistic regression adjusted for smoking and for asbestos exposure. In the entire study area, no rate ratios different from 1.0 were found; in the radon-prone areas, the adjusted rate ratios for expo sure in the present dwelling were 1.59 (95% confidence interval (Cl): 1.08, 2.27), 1.93 (95% Cl: 1.19, 3.13), and 1.93 (95% Cl: 0.99, 3.77) for 50-80, 80-140, and >140 Bq/m(3), respectively, compared with 0-50 Bq/m(3). The ex cess rate ratio for an increase of 100 Bq/m(3) was 0.13 (-0.12 to 0.46). An analysis based on cumulative exposure produced similar results. The result s provide additional evidence that residential radon is a risk factor for l ung cancer, although a risk was detected in radon-prone areas only, not in the entire study area.