Risk of death from solid cancer among residents of the Techa riverside and the East Urals radioactive trace areas exposed to radiation: comparative analysis

At present knowledge of health risks and health effects of protracted exposure to low and moderate (less than 1 Gy) doses of ionizing radiation is incomplete. Data from long-term follow up of cohorts of sufficient size can be important source of information for analysis and for filling in the knowledge gaps. The purpose of the study is to present results of comparative analysis of long-term health effects of exposure of residents of the Techa riverside and the East Urals Radioactive Trace areas to radiation due to the operation of the nuclear complex Mayak. The average accumulated dose to soft tissues received by the population is 30-40 mGy. Individual dose to members of the two cohorts were calculated with the improved version of the Techa River Dosimetry System TRDS-2009. Risks of death from solid cancer per dose unit in the cohorts of residents of the Techa riverside and the East Urals Radioactive Trace areas exposed to protracted low and moderate radiation doses are similar, a linear relation between dose and response suggests statistically significant association between the variables. Results from comparative analysis of the cohorts show the possibility to merge two cohorts into one, consequently to increase statistical power of the cohort and to decrease uncertainty in risk assessment.