Objective: Assessment of effects of environmental factors on development of lung cancer. Methods: We applied a multiple factor approach to designing the epidemiologic study. The object of our research was the town of Karpinsk, the Sverdlovsk Region, situated within the environmental radiochemical area with a high radon potential characterized by a moderate level of contamination of the natural environment and high cancer incidence rates among the local population. The case group included 142 lung cancer patients and the control group consisted of 220 people without cancer. We analyzed health effects of 12 biological, social, occupational, and environmental factors. We used the deterministic algorithms of pattern recognition for the multifactor data processing. Results: We have established the power and nature of the effect of each factor under study on development of lung cancer. Using mathematical modeling, we assessed efficiency of hypothetical scenarios of some risk factors correction. Conclusions: Among the lung cancer environmental risk factors in Karpinsk, indoor air pollution with carcinogenic brown coal combustion products was of great importance; the contribution of indoor exposure to radon isotopes was low (0.9 %).