Washington, 29 July 1997 (RFE/RL) -- A new government study says that millions of Americans were exposed to potentially dangerous radiation as a result of atomic bomb tests conducted by the U.S. government in the 1950s and 1960s.
Officials at the U.S. National Cancer Institute (NCI) released partial information from the study late last week, but the complete report with an estimated 100,000 pages will not be released until the end of the year.
The report will detail how a radioactive substance called iodine 131 -- produced as a result of an atomic bomb explosion -- traveled through the air from the desert test site in the western state of Nevada and contaminated areas as far away as the northeastern states of New York and Massachusetts.
Preliminary information released by the NCI indicates that the vast majority of Americans (estimated at about 160 million people in the late 1950s) were exposed to about 2 rads -- considered to be a low amount of radiation and about the same amount that was used in various medical scans during that time.
However, the study also shows that people living closest to the test sites, especially to the north and east of the test site had the highest doses, averaging 5 to 16 rads.
Children, aged 3 months to 5 years, were considered the most at risk by the study because they consumed large quantities of milk and their thyroids are smaller.
Some medical experts believe there is a strong correlation between the radioactive substance iodine 131 and cancer, especially in the thyroid, a gland that secrets a hormone which regulates body growth and metabolism..
Officials at NCI say that their medical investigators worked in cooperation with scientists and doctors in Belarus and Ukraine to study thyroid cancer in children in those countries who were exposed during a nuclear accident at the Chernobyl plant in 1986. Researchers have discovered that children in the immediate Chernobyl area have a much higher rate of thyroid cancer compared to the world's average.
However, NCI says it will be hard to make a direct correlation between the two cases because people in the immediate Chernobyl area were estimated to have received iodine-131 doses ten times higher than those persons living near the Nevada test sites. Still, NCI says it does consider the Chernobyl findings "relevant" and they will be detailed in the final report.
In conclusion, NCI says that while their study produced "suggestive" evidence that iodine-131 may be linked to cancer, it in no way should be considered "conclusive."
The study is interesting because it is based completely on mathematical models. Scientists did not examine people. Instead, researchers based their models on 90 nuclear tests that produce iodine-131 and relied on weather data to determine precipitation and wind direction. Also studied were the location of farms and agricultural centers and whether or not herds grazed in areas were radiation fallout might have occurred.