FEATURE ARTICLE
Fallout from Nuclear Weapons Tests and Cancer Risks
Exposures 50 years ago still have health implications today that will continue into the future
Steven Simon, André Bouville, Charles Land
Historical Background
The first test explosion of a nuclear weapon, Trinity, was on a
steel tower in south-central New Mexico on July 16, 1945. Following
that test, nuclear bombs were dropped on Hiroshima and Nagasaki,
Japan, in August of 1945. In 1949, the Soviet Union conducted its
first test at a site near Semipalatinsk, Kazakhstan. The U.S., the
Soviet Union and the United Kingdom continued testing nuclear
weapons in the atmosphere until 1963, when a limited test ban treaty
was signed. France and China, countries that were not signatories to
the 1963 treaty, undertook atmospheric testing from 1960 through
1974 and 1964 through 1980, respectively. Altogether, 504 devices
were exploded at 13 primary testing sites, yielding the equivalent
explosive power of 440 megatons of TNT (see Figure 2).
The earliest concern about health effects from exposure to fallout
focused on possible genetic alterations among offspring of the
exposed. However, heritable effects of radiation exposure have not
been observed from decades of follow-up studies of populations
exposed either to medical x rays or to the direct gamma radiation
received by survivors of the Hiroshima and Nagasaki bombs. Rather,
such studies have demonstrated radiation-related risks of leukemia
and thyroid cancer within a decade after exposure, followed by
increased risks of other solid tumors in later years. Studies of
populations exposed to radioactive fallout also point to increased
cancer risk as the primary late health effect of exposure. As
studies of biological samples (including bone, thyroid glands and
other tissues) have been undertaken, it has become increasingly
clear that specific radionuclides in fallout are implicated in
fallout-related cancers and other late effects.
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