ABSTRACT
The ALC has eondaeted a survey of the total radioiogicat environment of Lnewetak Atoll in order to
provide oata for judy uetity as ta whether or not all or any part of the Atoll ean be safely
reinhibited, More than 4500 sainples from ali parts of the manne, terrestrial, and atmosphenc
eomponents of the Atoll onviren-nent were analyzed by instrumental and radiochemical methods.
audition, an aerial survey for gamma-radiation levels was conducted over all land areas,
The *
In
TT 1 BOogCha and 2 "Py are
ine
.
M5 now present, Bul Uicir
i
ire the , predominant
radiqaetive
isctopes
arstribution ts far from unitorm. islaads on the southern half of the Atoll from ALVIN to KEITH
hive levels of contamination ecinpartanie to or less than those due to world-wine fallout in the
United States. On the northern half, ishinds ALICE to IRENE are iiost heavily contaminated, KATE
to PEELALA are least contampiated, and J VNED is at an intermediate level.
[nese radivlogical data have bean combined with the best information currently available on the
expecteu diet uf the Lnewetak people to estimate potential whoie-budy and bone dose, to the
population for «ix living patterns at S-, ld-, 30-, and 7O-yr intervals after return. Thirty-year
integra) Gove estates for unmodified die., current) conditions are shown in Fable A.
Vable A.
Corrective actions to reduce population doses will te mast heneficial if they are directed at the
primary contrinutors, ica., pandanus and breadfruit in the diet and external gaia dose in the
reanicnee areas,
Since neither pandanus nor breadfruit are naw growing on the Atoll in sufficient
amounts to provide a significant dietary component, control of the lecation and manner in which
they are reestablished will have a direct influence on the population doses from these fruits, If
their growth were limited to the southern islands, for example, and the population Living on JANLI
webe to truport them rather than grow thein locally, the expected 30-yr bone dose would be reduced
from 60 to 25 rem and the whole-body dose frou |] to 6.5 rem. Saroilar results would be obtained if
uneontaininaled soul were imported to JANL] for the establishiient of these plants.
over the land surface.
Tabte ft.
Poreentage of total $0-yr terrestrial food dove to a population Cagagel in agri@ulture
on JANI.1.
load
Unmodified conditions
Living
pattern
Inhalation
Bone
bung
Liver
I
External
Rone,
DB.
TAT
al-4)
4-4
i
120
O.UI6
OLA
LB
27
i]
0.10
0.13
O.056
4.0
Ik
WAT
0.59
0.24
\
ud
Odd
6.053
2.4
vl
OG
EL
u,044
4.4
Lawirye
wetter
0,83
Terrestrial
AGE.
Hone
lo.
Sabla shard
O44
2.1
Marine
ha He.
Bone
Total
LH.
Rone
Yg- dose
to bone,
1 5 dose
to whole body,
Lomestio meat
i
Pandanus fruit
40.
26.
35.
Greadfrait
14,
28.
Wild birds
1.005
0.003
3.8
Bird eggs
0.05
W002
44
5.
Areowraot
a
0.3
(oronul meat
6.
g.
Coconut ink
0.4
L.
0.84
33.
fad
0.34
6.4
75.
1.053
U.b4
11.
:
71.9
210.
0.953
uB4
31,
220,
27
33
9.053
(1.84
9.6
130.
OG
84
7
14.
37.
135.
Wisbte trou
I
Pac tdavhd be ey AS
ALLEN through RiTTIL
Southern islands
II
PREPPED ER/DASTD
KATE through FILA
plus LEROY
Northern stands
tel
Hvenl
JANLT
Northern Ishands
Iv
HELL
BELLE
Narthern Islends
V
JANE
‘1
JVNIE
IWATE through WLWA
_
1.0
0.053
Agriculture
Attempts Co
ablain the seme results by reinoval of Wee and 138% os-eontaminated sot from JANET would
require denuding of the entare island because of the relatively uruform distribution of these isotopes
The 3f-yr integral dose for six living patterns, assuming unmodified conditions,
d0-year integral dose, rem
OF
pindunus and breadfruit. Percentage contributions to the S0-vr integral dose for each of the
terrestrial food items for 4 population engaged in aymeulture on JANET are shown in lable B
phus EEROY
Northern islands
ALICE through IR LSE
Northern Ishands
The wnain contribution to the population dose canies through the terrestrial food pathway, followed
in deercasing order of sigmflicanee by the external gamma dose, inarine, and inhalation pathways, In
the terrestrial food pathway, the iain contribution te both whole-body and pone dose is due to
Stpnifieant reduction of the external gama dase may be achieved by placing a
n. laver of clean
gtuvel in the village areas and by plowing the agricultural areas. On JANT I, for example, use of
these procedures reduces the expected J0-yr external dase from 4.0 to 1.7 rem.
Thus, fram Tatke \otfoas clear that a very bread range of population Goses
Ay be expected,
Joparmding of village islane, agricultural ishand, and living pattern,
[tis equally clear that
substeritial reductions of the higher doses can be iehreved through relatnely simple modification of
the agricultural praetioes and of the sui, Table © suinmarizves the reduction that could be expected
tron: these actions far a population living on J VN EL.
(he island of YVONAEL presents a unique hazard on Lnewetak Atoll.
Pure plutonium particles are
present on or close to the grounc surface, randomly scattered in “hot spots" over most of the area
fro the tower to CACTUS crater. {xamination of these "hot spats" has revealed the presence of
oceustonal milligrenicsize pieces of plutanvam tietal, as well as Sinailer pietcs which are physically
incistinguishable in size frou the surrounding eoral matrix. Civen these current conditions, it must
he assumed that pure plutoniun, particles of respirable size ate naw also present on the surface or
ny be present in the future as weathering effects oxidize and break down the larger particles.
Lung duse assessnients for this area, therefore, mist be based un inhalation of pure plutonium
particles rather than thase having the average Mutontum content of the soil
Ihe potential health hazard via the inhalation pathway is sufficiently great to dictate two basic
alternatives for remedial actian for this island: (1) Viake the entire island an exclusion area--off
limits to all people, or (2) conduct a cleanup campaign which will eliminate the "hot spot" plutonium
problein and reinove whatever nmount of soil is necessary to reduce the soil plutonium
eoncentration to a leve} comparable to other northern islands. As an indication of the volumes of
sell Involved, removal of a )G-em thick laygr of topsoil in the area in which "hot spots" have been
detected involves approxunately 17,f00 m”
of material Further removal of soil to reduce the
inaxiium plulomium contamination levels to 50 pCi/g or Less involves an additional 25,000 im of
madlerzal.
FIGURE 2-1. ABSTRACT FROM ENEWETAK RADIOLOGICAL SURVEY REPORT, NVO-140.