Opinion on reconsideration of lung cancer risk from domestic radon exposure

Abstract

Two extensive collaborative meta studies including 13 residential case-control studies from Europe and 7 from North America have demonstrated that domestic radon clearly poses a risk for lung cancer at exposure levels approaching those for underground miners. An excess risk for lung cancer of 0.08–0.16 per 100 Bq/m3 increase in radon concentration was obtained, with a positive trend of increased relative risk at above 200 Bq/m3.However, estimation of the cancer risk associated with domestic radon obtained by the pooling of multiple case-control studies has led to inaccuracies of the derived risk estimates in the low dose range, mainly due to smoking misclassification bias, uncertainties with respect to radon dosimetry, the histopathological characterization of lung cancers, as well as confounding by co-exposures with tobacco smoke and other indoor air pollutants. Together with a lack of biological plausibility, these deficiencies have a negative impact on the reliability of reported statistical relations between radon exposure and lung cancer at concentrations below 200 Bq/m3.It is vital that costly remedial actions to reduce domestic radon exposure are based on a scientifically robust risk assessment, and in view of aforementioned flaws, the hitherto proposed risk estimates need to be reconsidered.

Keywords

• Domestic radon
• Dosimetry
• Lung cancer
• Histopathology
• Risk estimate
• Misclassification