THE ESTONIAN STUDY OF CHERNOBYL CLEANUP WORKERS .2. INCIDENCE OF CANCER AND MORTALITY

A cohort of 4,742 men from Estonia who had participated in the cleanup activities in the Chernobyl area sometime between 1986 and 1991 and w ere followed through 1993 was analyzed with respect to the incidence o f cancer and mortality. Incidence and mortality in the cleanup workers were assessed relative to national rates. No increases were found in all cancers (25 incident cases compared to 26.5 expected) or in leukem ia (no cases observed, 1.0 expected). Incidence did not differ statist ically significantly from expectation for any individual cancer site o r type, though lung cancer and non-Hodgkin's lymphoma both occurred sl ightly more often than expected. A total of 144 deaths were observed [ standardized mortality ratio (SMR) = 0.98; 95% confidence interval (CI ) = 0.82-1.14] during an average of 6.5 years of follow-up. Twenty-eig ht deaths (19.4%) were suicides (SMR = 1.52; 95% CI = 1.01-2.19), Expo sure to ionizing radiation while at Chernobyl has not caused a detecta ble increase in the incidence of cancer among cleanup workers from Est onia, At least for the short follow-up period, diseases directly attri butable to radiation appear to be of relatively minor importance when compared with the substantial excess of deaths due to suicide. (C) 199 7 by Radiation Research Society.