Background: Results of numerous epidemiologic studies of carcinogenic effects
of indoor radon conducted in different countries in the past 40 years remain
controversial. To assess the contribution of the residential radon exposure
in the development of lung cancer in the population of the Russian region
with a high radon hazard we conducted a cancer epidemiology study based on a
multifactorial analysis. Methods: The study was conducted in the town of
Lermontov situated in the area with high background radon concentrations and
lung cancer rates of the Caucasian Mineral Water Region of Russia. High
indoor radon levels were found in the houses of urban residents, mostly
employed by the mining and chemical enterprise. The cohort consisted of 122
lung cancer cases and 208 controls. Each of 330 study participants was
characterized by a set of 23 indices reflecting known lung cancer risk
factors. We also collected data on occupational and residential radon
exposure of all subjects. Results: The analysis of a combined effect of 23
different lung cancer risk factors based on pattern recognition methods
showed that the contribution of the non-occupational radon exposure was only
about 2% whereas that of the occupational radon exposure equaled 15%.
Conclusion: Our findings showed that the effect of the residential radon
exposure on the lung cancer rate was 15-20 times weaker than the effects of
the main risk factors such as smoking, occupational hazards, chronic lung
diseases, social and household factors, etc., although for the population of
Lermontov this factor was 2-3 times stronger than that found in the Ural
towns of Russia.
Potential lung cancer risk from indoor radon exposure
