UNIQUE DOCUMENT
fine
.
te
hee
clearly marked by appropriate signs. No contamination causing combined betagamma reading exceeding twice background was at any time left on the body of any
personnel, and no clothing was worn which showed a combined beta-gamma reading
exceeding twice background,
3.025
:
:
~ oo.
een:
)
Summary
The principal result of the BIXINI SCIENTIFIC RESURVEY was to show that the
atomic explosions caused only minor, transient disturbance to the plant and ani-
mal populations of the area, the effects of which have almost completely disappeared after one year's time, Some plants and animals in the immediate area
of the underwater explosion were killed and some highly radioactive plants, fish
and invertebrates of impaired vitality were found in the three weeks following
test Baker,
One year later, a most careful search of the islands, reefs, and
lagoon by some twenty very well-qualified and well-equipped and well-supported
biologists, over half of whom had made extensive studies of the same areas before
the explosion, revealed no changes in population, numbers, or composition, and
no physiological damage which definitely could be ascribed to the explosion,
The nearest thing to a case of definite damage from the products of the explo-
)
sions ig furnished by some dying corals on the reef between Amen and Bikini
Islands, These corals (Heliopora) were observed to be in fine condition a few
weeks before test Baker, At the time of the explosion the tops of the coral
clumps were about a foot under water, and the tide was rising. They may have
been killed by radioactive fission products definitely kmown to have washed over
the reef after raining down from the base surges, Other possible causes of their
death are contamination by o11 from the sumken shipe, patches of which can still
be found on almost all the reefs and beaches, or by heavy rain during one of the
lowest tides, Corals are easily killed by fresh water.
happened to these particular corals remains open,
The question of what
Large amounts of radioactive material still exist on the lagoon bottom,
‘Above the water, the external radiation is appreciably greater than background
only on the sand apit at the northern end of Bikini Island and the adjoining
reef, and near debris from the target ships cast upon various beaches, Even
there, it provides no physiological hazard. In the habitable portions of the
islands, any radiation from fission products is so weak as to be completely lost
in the normal background. In the waters of the lagoon, the residual radioactivity from the bomb is similarly lost in the radioactivity normally present in sea
water the world over,
Of approximately a thousand plant and animal samples,
mostly fish, which were counted or analyzed, the average radioactivity per unit
weight was approximately fifty per cent more than that of the body of a man who
has had ho exposure to radium, fissionable material, or fission products; and in
only one sample, a sponge, was the energy per wit volume being received from
radioactivity as much as it would have been from the accepted tolerance of ex-
ternal radiation, 0.1 R/2k hours,
j
Other than fish, no food product was found
which contained more than twice the normal radioactivity of human flegh, The
maximum amount of plutonium found in any part of any fish was 3 x 10°-"
grams
per gram of wet tissue, When it is remembered that two of the dangerous long-
life fission products, strontium and cesium, are not now present at Bikini and
that the fission product activity still present there will have decayed to about
30 per cent of its present value after one more year, and that from food saten,
somewhere between 1 and 10 per cent of the radioactive material is retained by
the body, it becomes obvious that after a few more years these islands will
constitute relatively slight radioactive hazard to any one,
Nevertheless,
definite predictions cannot yet be made as to whether the radioactivity will
soon become sufficiently diluted to permit permanent reoccupation of the atoll.
- 102 (1) -
DEPARTMENMDF ENERGY DECLASSIFICATION
SINGLEREVIEW AUT
ED BY: DETERMINATION [CIR
Ss
REVIEWER (ADD
NAME:
DATE:
7
7
1. CLASSIFICATION
De