Because of an editing error, an article yesterday about nuclear tests by the military incorrectly described the atomic bomb dropped on Hiroshima. It had a destructive force equal to 12.5 kilotons of TNT.
A study of U.S. servicemen exposed to radiation during nuclear tests in the 1950s has shown no evidence of increased cancer deaths except in exposures to two atomic blasts, according to a study released yesterday.
The report, by the National Research Council of the National Academy of Sciences, noted that there were more than twice as many leukemia deaths as could have been expected from participants at the 1957 Nevada test shot nicknamed Smoky, and double the expected prostate cancers among witnesses at the Redwing test-shot series on the Eniwetok and Bikini atolls in the Pacific in 1956.
However, the study concluded that "When the data from all the tests are considered, there is no consistent or statistically significant evidence of an increase in leukemia or other malignant diseases in nuclear-test participants."
The authors studied records of 5,000 deceased veterans among 46,000 who participated in five nuclear-test series held in Nevada and on the Pacific atolls between 1951 and 1957.
Altogether, about 250,000 servicemen were involved in 18 series of nuclear tests between 1946 and 1963. Since then, a large number have suffered cancer and other diseases and have sought compensation from the government, saying their ailments stem from their exposure to radiation at the tests.
The Smoky study results support a 1979 finding by the federal Centers for Disease Control, which first publicized the excess leukemia deaths in soldiers exposed at the Nevada test.
The report said the excess leukemia "either was a chance aberration or argues that the mean radiation doses at Smoky . . . were several times the doses recorded by the film badges that were used." It based that conclusion on the fact that excess leukemia deaths did not turn up among participants in other tests, although records showed that they received the same exposure levels.
One study author pointed out yesterday that Smoky, a 44-kiloton device (the atomic bomb that was dropped on Hiroshima weighed 12.5 kilotons), was set off from a 700-foot tower and was "a dirty shot." He said badges worn by troops who marched through ground zero minutes after the nuclear detonation did not measure neutrons or neutron-induced radiation in the soil that was blown about by helicopters and inhaled by the soldiers.
Redwing findings are considered more of a "statistical blip" than anything else, the source said. He said 16 cases of prostate cancer occurred, compared with the eight that could have been expected among the participants. But, he added, there has been no previous indication that prostate cancer is caused by radiation, even among victims of the atomic bombs that were dropped on Japan.