has a half-life only fifteen times greater than radium.
In
addition, the quantities to be isolated, purified, and used
for a variety of purposes were cons{derable, to say the least.
Later, several other of the heaviest elements, commonly called
the actinide elements, which extend fran actinium through
curium (element 96) were included for study.
These substances
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either arise directly in the chain-reacting pile or appear in
certain phases of the atomic energy program and present
potential health hazards because they al} share the canmon
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property of radfoactivity.
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There was also information avaflable on fallout from atomic weapon detonations.
Livestock that were exposed to localized°fallout fran the Trinity Shot
in New Mexico in July, 1945 showed effects of the exposure (beta burns on the
skin) (Glasstone et al., 1950).
Fallout occurring at more distant locations
was also observed in August, 1945, in Indiana, when photographic film was
fogged by radioactive contaminants in packaging materials (Webb, 1949).
Research on fallout from Trinity continued for a number of years after the
detonation (Larson, 1963).
Glasstone et al. (1950) discussed the effects of these weapons, briefly
mentioning the potential of serious physiological hazard of radioactive
fallout that deposits on the earth's surface in appreciable amounts.
These
authors also cons{dered the problems of radioactive contamination of food and
water, and tabulated fission products and their relative importance at varying
times after fission.
In addition, the biological significance of uwnfissioned
uranium or plutonium released into the environment was also discussed.
Information on fission-produced internal emitters seems to have developed
in three major phases.
In the 1940s, studies related to the metabolism and