Lung cancer mortality and radon exposure in Russia

The association between the lung cancer and indoor radon exposure in Russian population was investigated. The average indoor radon concentration for each region was estimated using the annual reports issued by the Saint-Petersburg Ramzaev Research Institute of Radiation Hygiene for the period 2008–2013. The average standardized lung cancer mortalities among males and females were estimated using the reports of the Moscow Hertzen Cancer Research Institute for the period 2008–2012. The relative risk (RR) was estimated as a ratio between the average mortality within seven exposure intervals and background mortality. The slope factors of linear dependence between the indoor radon exposure and lung cancer RR are 0.026 (−0.11÷0.17) and 0.83 (0.52–1.12) per radon concentration 100 Bq/m³ for males and females, respectively (with 90% confidence interval). The obtained results can be explained by the confounding effect of tobacco smoking. Significant excess risk of lung cancer in female population can be associated with radon exposure and low prevalence of smoking.