37
Rongelapas a result of their fallout radiation ex-
mass and/or total blood volumewith total body
weightused as a base line. During the 1963 survey,
similar studies were performed on 21 Marshall
posure. Attemptsat 8 and 9 years post exposure
to obtain suitable blood cultures had not been
entirely successful. However, during the 10-year
Islanders, but these data were related to total
survey a slight modification of the Moorehead
technique’® resulted in a series of satisfactory
cultures on 51 peopie: 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. The detailed results of these studies are
presented in Appendix 14.*
body water as determined by tritiated water.'°
Results showedthat in all instances but one the
values for red cell mass and total blood voiumefell
below normallevels for persons living in temperate
zones of the United States.
The present study was undertaken during the
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 by the same techniques.* Theresults of these studies on each individual are presented in Appendix 15, along with data on the 21
Marshallese in whom these studies were carried
out in 1963. The data were programmed and
analyzed by a high speed digital computer. Re-
Table 25 summarizes the results. A higher in-
cidence of aneuploid cells was noted in the exposed
group, but the difference was not great enoughto
be significant. Unexpectedly, the lower exposure
group showed more aberrations than did the more
heavily exposed group,and the latter group showed
even less aberrations than the unexposed. How-
gression lines obtained for the Caucasians and the
ever, the incidence of 2-hit aberrations was significantly higher ( p <(0.004) in the exposed groups
Marshallese are presented in Figure 67 along with
regression lines of Moore” and Siri" for Americans.
The Marshallese regression lines for both blood
and did appearto be radiation induced. Figure
66 shows a dicentric and a ring form noted in
chromosomespreads from two exposed individuals.
volume and red cell colume have very nearly the
same slopes as the lines of the Siri and Moore
groups, but they are significantly below thelatter
(significant at the 1% level). The Caucasiansliving
in the Marshall Islands also show regression lines
for blood volumeand red blood cell volume with
slopes similar to those of the Marshallese and the
Siri and Moore groups. Comparison ofthe regression lines showsno significant difference between
OTHER LABORATORY STUDIES
Total Blood Volume and Red Cell Volume
Previous studies (1961, 1962) with °'Cr-labeled
erythrocytes on Marshallese subjects living in their
native environment have shown reduced redcell
*We are grateful to Dr. Shields Warren and his group at the
Cancer Research Institute in Boston for carrying out the chromosome analyses.
*Weare grateful to Dr. W_E. Siri, University of California. for
carrying out the tritium-water analyses.
Table 25
Summary of Chromosome Findings
Group
No. of
persons
persons
cells
scored
with
2n46
aberrations
No. of
of cells
Exposed
30
1500
10
Exposed
69 rads
13
650
8
8
400
5.5
175 rads
Unexposed
No. of
Percent
with
Chromosomeaberrations
Fragments
Dicentrics
12
Lt
6
-
5
11
(84.6%)
10
2
1
8
9
~
-
-
(40% )
5
(62.5%)
ExRings changes
Total
Total
aberrations
22
cells
with
aberrations
Chro-
Tso-
matid chromatid
breaks
gaps
(1.46%)
(1.33%)
20
43
15
21
(3.23%)
18
(2.77%)
31
+
6
5
9
(2.25%)
8
(2.0%)