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Background radioactivity and oceanographic conditions in
the Pacific Proving Ground are of significance; in evaluating
the contaminating effects of REDWING events, in the understand-
ing of the fallout problem at sea and extrapolation to land
fallout patterns.
Thus, as a part of Project 2.62, a month-
long study has been made of radioactivity in water, organisms,
and bottom sediments, and of currents and physical character of
the water over a 140,000 square mile area around Bikini Atoll.
The waters are slightly radioactive, with values of 150 to
1500 gamma counts per minute per liter (cpm/1), whereas the
natural radioactive background, due to potassium-'C, is about
gt cpm/l.t
A field of maximum activity (8CO to 1500 epm/1)
exists at 300 to 1200 meters depth at locations to the west of
Bikini Atoll, within 150 miles of it, and between 104° and
133° N.
Radioactivity is associated with particulate matter
(possibly organic) at the surface only; at all other depths it
is mostly in solution.
Organisms collected from the upper lay
ers and deep sea fauna captured in a trawl as deep as 2500
meters depth are about equally radioactive; the level of activity in these marine creatures is about 30 to 50 times as much
per unit weight as that in equivalent weight of water.
Lagoon
waters and surface waters in the open sea around the lagoons
are slightly more radioactive than other areas
(1100 to 2100
epm/1).
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All values of radioactivity given in this report are gamma
rays emitted per minute.
gpieDs093
YAN RG”
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ABSTRACT