O-159 Does radon cause diseases other than lung cancer? Results from the German uranium miner cohort study

Abstract

<h3>Introduction and Objectives</h3> Radon is an established risk factor for lung cancer. Less clear is whether radon causes other diseases than lung cancer. To further investigate such risks, updated mortality data from the German uranium miner cohort study (1946–2013) were analyzed. <h3>Methods</h3> The cohort includes 58,974 men who were employed for at least 6 months between 1946 and 1989 at the former Wismut uranium mining company in Eastern Germany. Considered endpoints were mainly cancers other than lung cancer, circulatory diseases and non-malignant respiratory diseases. Exposure to radon and its progeny and external gamma radiation was retrospectively estimated through a comprehensive job-exposure matrix. Statistical modelling was performed by internal Poisson regression for grouped data with baseline stratification by age and calendar year. Excess relative risks (ERR) per 100 WLM (Working Level Month) and 95% confidence intervals (CI) were estimated for cumulative 5-year lagged exposure to radon (mean=280, median=33, max=3,224 WLM). <h3>Results</h3> Within the follow-up period 1946–2013, a total of 5,122 cancer deaths other than lung cancer occurred. In this group, a statistically significant association was found (ERR/100 WLM=0.014; 95% CI: 0.006, 0.021). Regarding individual cancer sites, the majority of risk estimates were positive (14 out of 18), and two of them reached borderline significance (colon and liver cancer). This holds true even after adjustment for external gamma radiation. No increased ERR/100 WLM was found for the groups of deaths from circulatory diseases (n=10,665) and from non-malignant respiratory diseases excluding silicosis/other pneumoconiosis (n=1,674). <h3>Conclusion</h3> Our findings provide some evidence of an increased mortality risk for cancers other than lung cancer associated with radon. Chance, confounding by unconsidered risk factors and uncertainty in exposure assessment cannot be completely ruled out. If present at all, the radon-related risk for diseases and cancers other than lung cancer is substantially lower than that for lung cancer.