The possible influence of errors of radon exposure assessment on the results of planned national case-control study has been analyzed. It is demonstrated that, in general, the errors are classical multiplicative errors. It is demonstrated that the classical multiplicative errors of radon concentration measurement are not constant in all radon concentration ranges. At low radon concentrations, the additional influence of Poisson error on the measurement result should be considered. The modeling of the influence of errors of radon exposure assessment on slope factor of the dependence of lung cancer incidence on radon concentration in dwellings was conducted. It was shown that the expected level of radon exposure errors can reduce the observed value of slope coefficient at least twice in comparison with the original value for error-free study. The correction of the results of linear assessment of exposure-effect slope coefficient under the influence of measurement errors was realized by regression calibration technique and SIMEX extrapolation method. Regression calibration method gives the best results in restoring the original unbiased value of exposure-effect slope coefficient. The SIMEX method also allows the obtainment of the good assessment of expected value of the slope of exposure-effect dependence, but it should be noted that this method may lead to the underestimation of the real value of slope coefficient. An additional and the most powerful source of error in the radon epidemiological studies is the influence of smoking and the correlation between smoking status and radon concentration in dwellings. The modeling results demonstrated that maximum attention should be paid to the stratification by smoking status and other possible factors simultaneously influencing radon concentration in dwellings and lung cancer incidence.

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