LEUKEMIA INCIDENCE AND MORTALITY OF RECOVERY OPERATION WORKERS OF THE CHERNOBYL ACCIDENT: ASSESSMENT OF RADIATION RISKS FOR THE FOLLOW-UP PERIOD OF 1986–2014

Leukemia incidence in the cohort of Russian male recovery operation workers (liquidators) was estimated at 78110 people for the follow-up period 1986-2014. The average age of the liquidators at the time of entry into the zone of works for liquidation of the Chernobyl accident was 34 years. Radiation risk of leukemia incidence (with the exception of chronic lymphocytic leukemia) was analyzed for liquidators who had official data on the individual dose of external gamma radiation of the entire body accumulated over the period of work. During the follow-up period, 157 cases of leukemia were detected (with the exception of chronic lymphocytic leukemia). Collection and verification of data of hemoblastoses cases among persons exposed to radiation exposure was carried out according to a specially developed algorithm. The average dose of the liquidators was 108 mGy. During the period 1986–1997 was established a statistically significant (p<0.05) linear dose dependence of the leukemia incidence with an excess relative risk of ERR/Gy=4.17 (90% CI: 0.18, 13.24). From 1998 until the end of the follow-up period, as well as for the entire follow-up period (from 1986 to 2014), no statistically significant estimates of excess relative risk were found. For mortality, no statistically significant estimates of excess relative risk and relative risk were found for any of the observation periods. The obtained estimates of the radiation risk of morbidity indicate that a statistically significant excess leukemia incidence of liquidators, which may be associated with external gamma irradiation, is manifested in the first decade after exposure.

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