Combined analysis of onco-epidemiological studies of the relationship between lung cancer and indoor radon exposure

Abstract Objectives: Recent results of epidemiological and medical statistics studies of lung cancer and indoor radon in different regions of the world make a relevant new combined analysis of residential exposure health effects. In particular, new data were obtained by means of a meta-analysis of case-control studies as well as taking into account a confounding effect of human papillomavirus infection in studies of geographically aggregated data. Materials and methods: Two sources of epidemiological data are considered: (1) studies of ecological design and (2) case-control studies. Ecological studies included the analysis performed for the USA counties and Russian oblasts with adjusting for the main confounders. Data on the case-control studies were gained from the meta-analysis of 31 individual studies with a weighting of obtained odds ratios according to the quality of radon exposure reconstruction and size of the reference group. Estimations of lung cancer excess relative risk (ERR) associated with indoor radon exposure are combined. Results: Two types of epidemiological study design provided generally consistent EER estimations. The combined value of ERR due to radon exposure is 0.14 (90% CI: 0.10–0.18) per 100 Bq/m3. Conclusion: Available geographically aggregated data in regions of Russia and the United States and the meta-analysis of case-control studies conducted in a large number of countries confirm the association of lung cancer with indoor radon exposure.