a7
mass and/or total blood volume with total body
weight used as a base line. During the 1963 survey,
Rongelapas result of their fallout radiation exposure. Attempts at 8 and 9 years post exposure
to obtain suitable blood cultures had not been
entirely successful. However, during the 10-year
survey a slight modification of the Moorehead
technique’® resulted in a series of satisfactory
similar studies were performed on 21 Marshall
Islanders, but these data were related to total
body water as determined bytritiated water.*®
Results showedthat in all instances but one the
values for red cell mass and total blood volumefell
below normallevels for persons living in temperate
zones of the United States.
The present study was undertaken during the
cultures on 51 people: 30 in the higher exposure
group (175 rads), 13 in the lower exposure group
(69 rads) and 8 from the unexposed Rongelapese
who were on another island at the time of the
accident. Thedetailed results of these studies are
surveys in 1965 and 1966. A total of 19 Caucasian
Americans (3 females and 16 males) living in the
Marshall Islands for periods of 3 monthsto 9 years
were examined bythe same techniques.* There-
presented in Appendix 14.*
Table 25 summarizes the results. A higher in-
cidence of aneuploid cells was noted in the exposed
group, butthe difference was not great enoughto
be significant. Unexpectedly, the lower exposure
sults of these studies on each individual are pre-
sented in Appendix 15, along with data on the 21
Marshailese in whom these studies were carried
out in 1963. The data were programmed and
Oat wall
group showed more aberrations than did the more
heavily exposed group,and the latter group showed
even less aberrations than the unexposed. However, the incidence of 2-hit aberrations wassignificantly higher ( <(0.004) in the exposed groups
and did appear to be radiation induced. Figure
analyzed by a high speed digital computer. Re-
gression lines obtained for the Caucasians and the
Marshallese are presented in Figure 67 along with
regression lines ofMoore’andSiri"* for Americans.
The Marshallese regression lines for both blood
66 shows a dicentric and a ring form noted in
chromosomespreadsfrom two exposedindividuals.
volumeandred cell colume have very nearly the
same slopes as the lines of the Siri and Moore
native environment have shown reducedredcell
groups, but thev are significantly below the latter
(significant at the 1% level). The Caucasiansliving
in the Marshall Islands also show regression lines
for blood volume and red blood ceili volume with
slopes similar to those of the Marshallese and the
Siri and Moore groups. Comparison of the regres-
*We are grateful to Dr. Shields Warren and his eroup at the
Cancer Research Institute in Boston for carrying out the chromosome analyses.
carrying out the tritium-water analyses.
OTHER LABORATORY STUDIES
Total Blood Volame and Red Cell Volume
Previous studies (1961, 1962) with °'Cr-labeled
ervthrocytes on Marshallese subjectsliving in their
sion lines showsnosignificant difference between
*Weare grateful to Dr. W.E. Siri, University of California, for
Table 25
Summary of ChromosomeFindings
No. of
persons
No. of
cells
scored
Percent
of cells
with
2n3446
Exposed
175 rads
30
1500
10
Exposed
69 rads
13
650
8
8
400
3.5
Group
Unexposed
No. of
persons
with
aberrations
Chromosomeaberrations
Total
aberrations
Totai
cells
with
aberrations
5
22
(1.46%)
20
(1.33%)
43
15
1
8
21
(3.23%)
18
(2.77%)
31
4
-
-
6
5
Fragments
Dicentrics
Rings
Exchanges
12
(40% )
11
6
-
11
(84.6%)
10
2
9
-
5
(62.5%)
9
(2.25%)
8
(2.0%)
ChroIsomatid chromand
breaks
gaps