1456
PERSISTENCE OF TRITIUM AND “CIN THE PACIFIC PROVING GROUND
tritium in the Mike Crater area.
Since the
substratum materials are the same in Mike
Crateras they are on theislands, the same bound
source of tritium exists in the coral sand of
Mike Crater. The exchangerate of the tritium
from those particles is adequate to produce a
detectable local concentration in spite of the
mixing which would tend to disperse it. Pacific
Ocean seawater in the Marshall Islands area
was reported by IAEA) as containing 7.9 T.U.
ir, December 1602 The ievei oo” rmitiurr im
Mike Goater. thertiore. represent a ioc concentraton of at least 100 umes that of the
lagoon waters. Duplicate analyses were made
of the Mike Crater water sample andarelisted
in Table 4.
The tritium and 44C content of the animals
such as coral sand. In terrestrial environ
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the soil-bound tritium exchanges with the"...
soil water andis detectable in the plants w:.
rapidly equilibrate with the soil-watertrit,
levels, but the typical route of entryforcarly.
into plants is from the atmosphere through te
leaves. Nevertheless, as Tables 8 and 9 indj-...
44C content of plant samples is also e¢le-,..
Saniic
Halimed
Iguru
“arts
dr the Cattuy Omer ark wher us 2
was tie wargest. there is an indicauonof enn:
M4C in thelitter of .Vesserschmidia argentea and:
leaves of Triumfetta procumbens. The expec; .
44C content of Eniwetok plants is some valuele |
than 50 per cent (A per cent). Kuicosui a-Enpo™) gave 4C values for pine and Paulou;.. {
a slight increase over the lagoon waters with
which they should be in equilibrium.“®) There
any increment of 4C added to the world’s a.
mosphere from the 1961 high yield tests. Fey. i;
cusson)) indicated that byJuly 1962,the surface
area had the highest bound tritium content.
Moresignificant in marine animals, however,
is the enrichment of 1#C in their tissues. All
three animals from the Sanildefonso Island area
contain elevated !4C levels, with the fishes being
the highest. The hermit crabs apparently
obtained their 14C from the algal debris which
they ate at the water’s edge, because their
terrestrial diet of Messerschmidia litter does not
appear to be high in “C.
In the marine
environment of Eniwetok Atoll, residual tritium
and 4C boundin coral debris are released at a
slow but detectable rate and appear in the
animals of the marine detonation environment
at significant levels.
While tritium and 4C
ave qururted cheauchoic che dagann. Tahir &
demonstrates that thereis a definite localization
in the area of Mike Crater on the basis of the
14C content of animals living in that environment.
To characterize further the sources oftritium
in the Eniwetok environment and to demonstrate
the relationship with 3#4C, the values for the
soil samples collected in this surveyare commiled
Labora
givee Se
Qh wed
in Japan as 22.1 and 18.7 per cent for th |
is an indication that the animals from the
Runit reef environment and the Mike Crater
area have an enriched tissue-bound tritium
content. The hermit crab on Sanildefonso
Island and the surgeonfish from the Runit reef
= ee
apply only for a substratum high in carbon,.. ;
collected on Eniwetok Atoll are given in Table 6.
Tritium values for loose water in animals show
~
separately in Table 7, Theserelationships p_ -
1959-1960 wood. These values do not incluc, |
146C in the air had increased to 37.5 per ce: _
and in March 1962, grass in southern Califor.
had a 4C content of 20.7 per cent. The!:. values in Table 9 for woodare in this range, bu. ;
noneofthe areas sampledin this survey maytr ,
considered as uncontaminated and, therefore '
elevated levels of 4C may be expected anyplace
within the atoll. Wood from trees growingin the
Cactus Crater area have elevated #C valuc
and recent organic matter, leaves andlitter are
even higher. The typical route of carbon enin
into plants is from the atmosphere throughth
leaves. The basis of the elevated 1C in the
terrestrial plants is not evident in these data
but twopossibilities are suggested. The physic
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;
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logically specialized atoll plants may absor: |
compoundscontaining 1C throughthe roots, «
there is an increased 'C level in the immediz:"
ground-level atmosphere of the plants duct
ears cntunar Pom che seu! scare,
Further evidence for elevated “C levels intr: ;
c
Mike Crater area (Sanildefonso Island) wx
obtained from the analysis of a marine ai
collected in the Mike Crater area. Samples «i
algae from Igurin Islandat the southern endof
the atoll were also analyzed for 14C content anc
the values are included for comparison. D:
Rape Parmamo, University of Washiure !
The E
‘ected in
containin
was SuSP'
ievel wil
mental w
electrolyt
yielded a
and plar
therefore
In suit
survey
oC
Padine P:
$idum a
concentra
sites up t
soil-bounc
takes plac
tritium is
detonatio:
clevated i
the elevat
nary data
clevated «
However,
the lagoo
elevated c
the vicinit
ate .