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three or four times background. Only one fish collected (out of approximately
a thousand analyzed) in 1947 showed 4a higher concentration of radioactivity in
the entire organiam than in the feces. However, the average concentration in
the liver and spleen was about 50 per cent higher than in the feces, and the
average radioactivity in the kidmeys and gonads was also frequently considerably higher.
The marked concentration of radioactivity by plants two weeks after test
Baker and the reverse effect a year later undoubtedly reflect the different
identities of preponderant radiators at the two times. In 1946 the principal
fission products were atrontium, barium, bromine, rubidium, ruthenium, iodine
and cesium, A year later, because of radioactive decay or because of the flushing of the sea water, nearly all the radioactivity from these substances had
been eliminated in the lagoon, and only the heavier elements, yttrium, cerium,
zirconium and columbium,remain,
As shown by Overstreet and Jacobson these are
not appreciably absorbed by planta,
One of the most discussed effects of radioactivity ia the possibility of
producing genetic changes, At Bikini more than 1000 species of organiams have
been exposed to radioactivity, and many have reproduced through at least one
generation,
A careful search of the area by competent biologists, including
ichthyologists, botanists, invertebrate zoologists, and entomologiats, in the
course of which tens of thousands of specimens were examined, failed to reveal
definite evidence of aberrant forma, Since it is kmown that mutations produced
by radiation almost invariably have negative survival value, this result was
not unexpected, No interference with the reproductive functions of sea-urchins
taken from the most heavily irradiated portion of the reef could be detected.
The only obeerved effect considered related to the atomic bomb explosions was
an increase in catalase activity in three genera of algae taken in an area which
was probably exposed to high intensities of radiation.
In using the results of the Bikini Resurvey, with other information, in
planning the defense of the United States, one point needa special consideration,
At Bikini, three abundant long-lived fission products, strontium, cesium and
ruthenium, were not carried down by the mud because sea water contains abundant
material in solution to hold them back, In fresh water and on land this will
not be the case, and these elements will contribute detectible radiation in
heavily contaminated areas for many years, Another point worth noting is the
sharpness with which the present contaminated area ies now defined. During the
first few weeks after the explosion there ware many fission products remaining
in the water, and the boundary of the contaminated area was diffuse and variable
from day to day, and it was only after these had decayed or washed out of the
area that the boundaries became sharp, In fresh water or on land all fission
products may be expected to become fixed in the soil or mud almost at once, and
the boundaries will be sharp from the begiming,
contaminated area, or definitely out of it.
One will either be in a heavily
In addition to determining the long-term effects of atomio bomb detonation
which might be of military interest, it was the purpose of the Resurvey to conduct researches of a purely scientific nature. Many of these had been begun or
were suggested during the Crossroads Operation, During the Resurvey, information
was added to the fund of knowledge concerning the geology, oceanography and biology of Bikini Atoll, Some details of these studies are included in this report.
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The foregoing summary seta forth the present opinion of AFSWP staff,
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