Radiological Concerns
The primary radiological problems are the result of residual fission and activation products in the
terrestrial environment.
They have been identified by previous environmental surveys as follows:
1) Exe
ternal radiation levels significantly higher on some islands in an atoll compared to levels on lightly
contaminated islands.
2) Fission and activation product radioactivity in certain terrestrial food trems
now growing on islands of these atolls and the possibility thac unacceptable levels of these radionuclides
may appeat in foods, plants and animals newly introduced into these atolls.
3) Radioactivity in the
ground water, a possible source of drinking water and water for irrigation.
4) Pluronium and americiuim
{socopes in the surface soil,
These factors are illustrated by data in Tables 1 through 4 taken from
previous radiological survey reports.
.
Table 1.
Gamma Radiation Rates in Bikini Acoll™
Island
Bikini
Weathered areas
Close to shore
Island center
Hot spots
Eneu
Nam
Outer edge
Island center
N.E. corner
Bokantuak, Iomelan,
Rojkere, Eonjebi
Aerokoj-Emenman complex:
Aerokoj, Aerokojlol
Bikdrin, Lele
Eneman
East Eneman
West Eneman
Enidrik
East Enidrik
West Enidrik
(mR /br)
Exposure rate
Range
-010-,120
-010-.030
-020-.040
137
-010-, 330
60¢9,*?'cs
-010-,030
-110-, 330
-003-.010
ek
-001-,010
-006-.010
wk
we
"001.570
-001-+.010
-020-,570
,003~.235
-003+,030
Lukoj
Oroken
2015-.045
Bokdrolul
~020-,050
010.035
Bokbata
Aomen-Lroij complex:
wh
‘010~.030
Aomen
-005~.020
Odrik, Lrotj
.010~.040
Lomi lik
*
;060~. 200
-060-.136
Bokaetoktok
C83,
.015-.150
-010-,235
Jelere
-
Major contributors
T3/ Cg
-050-.,080
.080~. 120+
~002-.010
—
.020~. 330
.
Gc, 125g, 102m,
600, 1255, 102m,
“
6069, 125g, 102m,
wh
ek
we
6005, 376
%o9, 12555
Saad
See ref, 9.
;
No soil sample or field spectra measurements.
In some cases, che predicted doses and dose commitments derived from survey information for Bikini
and Enewetak Atolls approach or even exceed national and international radiation protection standards for
certaio living and dietary patterns.
Corrective actions or restrictions must be placed on use of these
atolls and their resources to assure that the applicable radiation standards are not exceeded,
Herein
lies the primary justification for the continuing environmental followup surveys sponsored by ERDA.
Environmental Monitoring
The most important sources of exposure to people living on Rongelap and to future
residents of Bikini
and Enewetak Atolls are from internal deposition of radicisotopes from certain elements in the human
diet, and from the long term occupancy of islands having external radiation dose rates higher than
natural background. Aside from periodic re-evaluations to establish trends in external dose rate
reduction, external radiation monitoring will assume less significance, compared to monitoring of che
food chain, as time passes.
At present, annual visits are being made to identify and collect repre-
sentative samples of local diets for laboratory analysis and dose commitment updates.
New locally
grown food items are becoming available in small quantities on Bikini Island as a result of the experimental agricultural practices of a small group of caretaker families living there.
Neither Bikini Atoll,
where radiological cleanup has been completed, nor Enewetak Atoll where clean up has not yet begun,
have a subsistence agriculture resource in being which is sufficient to suppore the anticipated populations which will one day live there (though such crops are currently being developed or planned).