The records search confirmed a total of 5,113 deaths from all causes. This number represents 11.1 percent of the study cohort, and when compared to U.S. mortality rates is 83.5 percent of the number of deaths that normally would be expected. Mortality in this cohort from accidents, acts of war, and other external causes was 6 percent higher than that expected, using U.S. population rates. On the other hand, the 1,046 cancer (including leukemia) deaths were only 84 percent of the number expected, and the 2,579 deaths from other diseases were only 69 percent of expectation. series was examined separately. Similar results emerged when each test However, a statistically significant excess number of deaths from prostate cancer (not thought susceptible to causation by radiation) was found among the Operation REDWING participants. As a check on the methodology used in the study, the SMOKY participants at Operation PLUMBBOB were subjected to the same mortality ascertainment procedures used for participants at other shots and test series. The sizeof the cohort increased to 3,554 participants, slightly higher than that of the CDC study, and 10 leukemia deaths were found. This incidence, 2.5 times the expected number (3.97), is considered statistically significant. No cancers other than leukemia were found in excess, and the total number of cancer deaths (67) was less than the number expected (83.8) using U.S. population rates. These results parallel those reported earlier by CDC and lend credence to the methodology pursued in the NRC study. The following conclusions, quoted from the published findings, resulted from the study (7): 1. The finding by Caldwell et al. that an excessive number of cases of leukemia has occurred among former participants at Shot SMOKY of the PLUMBBOB series was confirmed. 2. No evidence was found that leukemia mortality was increased among participants at PLUMBBOB tests other than SMOKY or among participants at UPSHOT-KNOTHOLE, GREENHOUSE, CASTLE or REDWING. 3. Generally accepted estimates of the rate of excess leukemia induction per rem when applied to estimates made by DNA of the radiation doses to participants result in an expected increase of leukemias among SMOKY participants of less than 0.2 case. The observed excess 187