50
RETURN OF RONGELAPESE
RADIOACTIVE CONTAMINATION OF AREAS IN THE PACIFIC OCEAN FROM NUCLEAR TESTS
Table 48 indicates that the average concentration of strontium—90 in the total food supply
might be less than 360 Sunshine Units.
(The
data on land crabs shown in Table 48 ere from
the Island of Kabelle which is more heavily
contaminated than the Island of Rongelap).*
Table 48—Estimates of Contamination of the Normal Food Supply of Rongelapese
A
B
Dany
INTAKE
Pounps/
AY)
PEESON
o
D
Carciou
Content
Damy In(gms cae TARE OF Ca|
‘wet weight)
(ms)
12
0.86
O2
0.09
0,08
90.03
0.02
0.01
0.001
0.001
0.004
40,0006
0.0002
G.004
0.0004
0, 0008
0.56
0.16
0.018
0.025
0.004
0.055
0.004
0.003
O12
~0. 0001
~0. 045
zg
¥
Conrtarev-
Fracrion
or Toran
Ca INTAKE
0.645
0, 184
0.021
0.029
0.0046
0.063.
0, 0046
0. 0034,
~0. 146
CONTENT
8. Ue
12
$500
5
250
300
+ + (4000)
40
260
Few
tion To
Bre
INTAKE
8. U,
Copomx
XE)
27
$92.0
on
7.26
661,38
(252.0)
0.02
0.88
Small
« Average values,
® These data are from island of Kabelle (no date from island of Rongelap for July 1956 survey). General contaminstion of island of Rongelap is
aboutone-fifth that of Kabelle, Lagoon water aroundthese islands do not show a9 great a difference in activity.
« These are land erabs from island of Kabelle. ‘The strontium-90 concentration Is higher than from earlier surveys, which is contrary to the plant
activity as well as to the sot!, and marinelife data. (It has been estimated that about one-third of the intake of crab meatis from ocean crabs which
havevery Httle strontium-00 content.)
¢ Estimated.
« An unknown part of this intake may be sea crabs (which contain considerably less Sr) but is assumed here to be all land crabs.
However, if crabs were eliminated from the diet,
the intake might average about 107 Sunshine
Units. Further,elimination or restriction of the
consumption of pandanus would reduce the
strontium-90 intake to well under 100 Sunshine
Units,
b. Estimated Future Body Burden of Strontium—
90
Three principal factors are operative in esti-
mating the future body burdenof strontium-90
of the Rongelapese: ©
@) Although precise values have not been
established, there may be a discriminatory
factor of several between Sr/Ca ratio in the
food supply and that found in the bones."
(2) If the Rongelapese were returned to
their homeisland, their diet would be supple-
this point. In any event the land crabs tested are from the island of
mented by imported (relatively uncontaminated) foods, especially rice. Also, the
cisterns would be cleaned out and refilled
with fresh water as well as having new
cisterns built.
is about one-fifth that of Kabelle, The difference in strontium-90 con-
analysis of the results from all of the surveys
“There is some doubt concerning the correct strontium-M0 activity in
the land crabs, since the values are higher than for previous surveys
which is contrary to ail other data. Additional surveys should clarify
Eabelle. (There were no collections of land crabs made on Rongelap
Istand during the tast survey.) The genera] contamination on Rongelap
tent may not be es great es this, but since these are land crabs tt would
be expected those on Rongelap Jeland to be iower than on Kabelle Island,
(3) Despite the wide variances in the data,
on the Pacific Islands shows a general decline
of Sr® with time in the food chain (except
the land crabs).
Although there is obviously a certain degree
of uncertainty, the above data and estimates
indicate thatif land crabs are eliminated from
their diet, the estimated future body burden
of the Rongelapese would be substantially less
than 100 zuc of Sr™ per gram of calcium. Limiting the intake of pandanus would further reduce
the estimated Sr® intake. By means of the
continuing medical examinations described below it would be possible to note any tendency
51
of untoward accumulation of strontium-90 with
time, and appropriate action could be taken
before excessive levels were reached.
c. Radiological Resurveys
Plans are currently being developed for a
continuing and long-range program for radiological resurveys on and around the Marshall
Islands. The principal objective will be to
monitor the environmental contamination especially for strontium~90.