Assessment of radon risk comparisons

Informing the public about the risk of lung cancer from radon in homes is a challenging task. Many people find it difficult to imagine a numerical indication of the level of risk and a radon concentration measured in Becquerels per cubic metre (Bq/m${}^3$). That is why it can be helpful to compare the lung cancer risk from radon with other risks (BMU 2019). The idea is that by comparing it with a better-known risk factor such as passive smoking, the risk factor radon and its risk also become more comprehensible. This report is the first overview of numerous comparisons of the radon risk in Germany with the risk of other risk factors. On the one hand, it examines for which risk factors such risk comparisons are possible from an epidemiological and dosimetric point of view. For this purpose, the study situation is assessed for each of the risk factors considered and it is examined to what extent the corresponding risks can be compared with the radon risk: Are the same endpoints considered (e.g. lung cancer or another disease)? Are the same populations studied (e.g. general population or never smokers)? Are the exposure situations comparable (e.g. chronic or acute)? How good are the exposure, risk and dose estimates in each case? Secondly, the report assesses whether the comparisons are meaningful from the perspective of risk communication. It may be that risk comparisons are possible from an epidemiological point of view, but problematic from a communication point of view, e.g. if the complexity of information is increased or the reception of the risk presentation is changed in an unintended direction (trivialisation, dramatisation).