Lung cancer mortality attributable to residential radon in Germany

The radioactive gas radon is one of the most important risk factors for lung cancer after smoking. This article aims to estimate the annual number of lung cancer deaths attributable to residential radon exposure in Germany and its federal states using updated data and an advanced calculation method. Data on lung cancer mortality (2018-2022), smoking behavior (2017), and on the estimated distribution of radon concentration based on a radon residential study (2019-2021) in Germany are used. The risk model employed is derived from the pooled European residential radon study, indicating that excess relative risk for lung cancer increases by 16% per 100 becquerels per cubic meter (Bq/m${}^3$) of corrected long-term radon concentration. It is estimated that a total of around 2800 lung cancer deaths per year (95% confidence interval (CI) 900-5100) are attributable to residential radon in Germany. This represents a population attributable fraction of 6.3% (95% CI 2.1-11.4%). Notably, radon-attributable lung cancer deaths occur not only among current (41%) but also significantly among former smokers (41%) and those who have never smoked (19%). The results confirm that radon in homes is an important risk factor for lung cancer, highlighting the need for protective measures against radon for all population groups in Germany.