CHAPTER V
Residual Activity in
Pacific Ocean
During February—May 1955, a survey was
made by the Health and Safety Laboratory of
the U. S. Atomic Energy Commission and the
Office of Naval Research (Operation Troll) of
the Pacific Ocean extending from the Marshall
Islands westward across the Pacific, northward
to Japan, then east to SanFrancisco.
2. There is some concentration of the
activity in the main current streams, such
as the North Equatorial Current. The
highest activity was off the coast of Luzon,
averaging 190 d/minfliter down to 600 m
(April 1, 1955).
8. Analyses of fish indicate no activity
The chart, on page 40 represents data on
approaching the maximum permissible level
Table 41 shows some representative data on
was 3.5 d/min/g ash, less than 1 percent of
42 and 43 show representative data for marine
4. Measurements of plankton activity offer
a sensitive indication of activity in the ocean.
activity found in sea water and plankton.
for foods.
activity versus depth of water sample. Tables
the permissible level.*
life.
Below is a summary of some of their conclusions:
1. Sea water and plankton samples show
theexistence of wide-spread low-level activity
in the Pacific Ocean. Water activity ranged
from 0-570 d/minfliter and plankton from
3-140 d/min/g wet weight.
The highest activity in tune fish
On June 11-21, 1956 another survey of radio-
activity in the sea was conducted near Bikini
and Eniwetok Atolls by the AFL.
Since this
survey was conducted during the Spring 1956
test series of detonations, temporarily relatively
higher activities might be expected. Table 44
summarizes some of the data.”
“Based on 1/10 m.p.c.of that for atomic energy workers.