Lung cancer mortality risk in the South Urals Population Exposed to Radiation Cohort

The objective of the study is to obtain risk estimates of lung cancer mortality for members of the Southern Urals Populations Exposed to Radiation Cohort. Materials and methods: The cohort, which unites individuals who were chronically exposed to radiation in the South Urals on the Techa River and in the East Urals Radioactive Trace, consists of 62,592 people. A regression analysis with a simple parametric model of the excess relative risk was used in the study. Results: Over the follow-up period from 1950 to 2020, 925 deaths from lung cancer were identified. The number of person-years at risk was 1964140. Mean accumulated lung dose calculated using the TRDS-2016 dosimetry system was 0.038 Gy and the maximum dose was 0.995 Gy. As a result of the analysis a statistically significant linear dose-dependence of the lung cancer mortality rate was obtained. The ERR/Gy for lung cancers with 2-year minimal latency period was 0.94/Gy, 95 % CI: 0.01–2.19; p < 0.05. Over the 71-year follow up period 3.5 % of lung cancer cases could be associated with radiation exposure in cohort. Analysis of baseline lung cancer mortality rates showed that smokers had 4 times higher mortality rates (p < 0.001). When analyzing the possible modification of the dose effect, a statistically significant relationship between risk and dose was obtained in women; in the group of Tatars and Bashkirs; in urban residents; in those who have cancers in first-degree relatives; in those exposed to radiation in the East Ural radioactive trace. Conclusion: Based on the findings of the accomplished study a statistically significant lung cancer mortality risk per 1 Gy has been established in the cohort of people affected by long-term radiation exposure in the low-to-medium dose range. The obtained results could serve as the basis to develop the program of preventive care for the population aggrieved.