Radiation doses and cancerrisks in the Marshall Islands @ S. L. Simon ET AL.
particles emitted during radioactive decay. In this analysis, we have not estimated the dose to skin or the
number of skin cancers that might be produced as a
consequence of exposure to fallout, primarily for two
reasons: (1) there are no baseline non-melanoma skin
cancer data reported by the Surveillance, Epidemiology
and End Results (SEER) program and other U.S. cancer
registries, and the baseline risks are an essential part of
the calculation to estimate the number of cancers, and (2)
the number of personal injury claims awarded by the
Marshall Islands Nuclear Claims Tribunal indicates that,
among the 2,046 awards made through June 2004, there
were 72 awards for skin burns, but only one award for
skin cancer (Marshall Islands NCT 2004). Hence, it
appears that, despite potentially high doses to the skin to
at least a small subset of the Marshallese, there is little
evidence that the risk of skin cancer is great among
Marshallese.
Estimated doses were derived for “representative”
persons, that is, for persons who could be described to
have habits, lifestyles, diet, and anthropometric charac-
teristics typical of the Marshall Islands population for
their age and sex (except in the case of military servicemen on Rongerik). Doses were assessed on a yearly basis
for exposures occurring from 1948, the year in which the
first relevant test took place, to 1970, when the residual
environmental contamination had reached negligible levels on most atolls. These estimated annual organ doses
were necessary input data for the cancerrisk calculations.
The estimated total radiation absorbed doses include
111
Table 4. List of radionuclides considered in estimates of deposition and of internal doses from acute intakes for the 20 tests
considered in this study (all are fission products unless otherwise
noted).
Nuclide
Half-life
SFe#
“Cur
TAS
8Br
8Rb
Sr
St
oy
2.7a
13h
39h
2.4h
18 min
5ld
29a
64h
LTSb
Te
2°Sb
Lint
By
eT;
127
3m
3.9d
70 min
44h
30h
8.0d
78h
2.3h
55 min
olmy
Str
my
By
50 min
2.7h
3.5h
10h
135]
BIC
Ba
MOBa
6.6h
30a
83 min
13d
MT a
Ce
PTa
3.9h
33d
91 min
3p
Ce
Mp
USP
MNd
14d
280 d
17 min
6.0h
lid
Sr
Zr
°Nb
he
*7™NIb
”Mo
mT
1E8RU
103Rh
Ru
Rh
9.6h
64d
35d
17h
538
66h
6.0h
39d
56 min
44h
35h
RU
Pd
370d
14h
'8Cd
53h
‘Ag
Cd
Lint
e'Sn
3Sb
LTSh
3.1h
25h
2.0h
27h
2.8 a
2.1h
Nuclide
By
MoTa
'8Ce
Pm
“Nd
Spm
35m
237[ya
40a
Homntp
229K?
239+ 240pb
Half-life
21h
1.7d
33h
53h
17h
28h
46h
6.8d
14h
7.2 min
2.4d
24,000/6,600 a
“ Activation product.
> Fuel material. Only cumulative depositions and intakesoverall tests were
estimated.
three components: (1) doses from external irradiation
emitted by fallout deposited on the ground; (2) doses
from internal irradiation from acute radionuclide intakes
immediately or soon after fallout after each test; and (3)
doses due to internal irradiation from chronic (..e.,
protracted) intakes of radionuclides resulting from the
continuous presence of long-lived radionuclides in the
environment. Sixty-three radionuclides, listed in Table 4,
were considered in the estimation of internal doses from
acute intakes of fallout radionuclides from each test.
Based on screening estimates, these 63 radionuclides
were estimated to account for over 98% of the internal
dose to any organ from acute intakes. In addition, five
long-lived radionuclides (Fe, “Co, Zn, ”’Sr, and '*’Cs)
were considered for the estimation of the internal doses
from chronic intakes, including two radionuclides, “Co
and ©Zn, that were not considered in the calculation of
the doses from acute intakes. Doses from acute and
chronic intakes from cumulative deposition of *?***°Pu
were also estimated.
Risks of radiation-induced leukemia and cancer of
the thyroid, stomach, and colon, as well as all other
cancer types combined, were assessed for the 25 Marshallese population groups on the basis of the estimated
radiation doses. Two time periods were considered: from
1948 through 2008 for the assessment of the radiationinduced cancers that have been expressed thus far, and
from 2009 onwards for the prediction of cancers that
remain to be expressed. For comparison purposes, the
numbers of baseline cancers, that is, those unrelated to
fallout exposure, are also reported.
SUMMARY OF METHODS AND FINDINGS
A brief overview of methods of the study and a
summary of the findings are presented here. Detailed
information can be found in individual companion papers. Throughout this section and elsewhere, we discuss
findings relative to four groups of atolls or communities.
Within each group, resident populations were exposed to
similar levels of fallout as a consequence of the dispersion patterns of the nuclear debris clouds. The southern
atoll group is well represented by Majuro, whichis the