Method for identification of high-risk groups among people exposed to radiation as a consequences of the Chernobyl accident

Identifying group of radiation risk of people exposed to radiation is the key area of focus for the National Radiation Epidemiological Registry (NRER) to be undertaken for execution of the Federal Law No 329-FZ of December 30, 2012. At present time initial medical and dosimetry information on more than 700 thousand people exposed to radiation as a consequence of the Chernobyl accident is stored in the Registry. The cohort composed of Chernobyl clean-up workers received the highest radiation doses. In the present study life-time risk of cancer and cerebrovascular diseases to clean-up workers operated in the Chernobyl exclusion zone in 1986 and 1987 were calculated. The size of the cohort under study was 74 thousand people, the average dose of g-radiation - 132 mGy. For estimating radiation risks models recommended by the International Commission on Radiological Protection (ICRP) to justify international standards of radiation safety and those designed at the NRER to estimate radiation risks to the cohort of Russian cleanup workers were used. The method for identifying groups of radiation risk based on life-time attributable risk fraction was designed. In compliance with international standards and regulations a group of high risk was composed of clean-up workers with individual life-time attributable risk fraction (LARF) estimates calculated with ICRP recommended and NRER-designed models exceeded 10%. The groups of high risk of cancer and cerebrovascular diseases identified with the use of the designed method consisted 6.5% and no more than 4.5% of the cohort members respectively. Presented results illustrate the applicability of the designed method for identification the groups of people exposed to radiation who should get appropriate health care in the first turn.