31
ment of cancer was 7 years in one case and 14 and
ture aging in the exposed group that mightbeassociated with radiation exposure.
During the past 3 years these studies have been
extendedto include examination ofsomeaspects of
the immunestatus in the exposed and unexposed
15 years in the other two. That the latent period
may be longer is supported by Goolden’s observation of the developmentof thyroid cancer 40 vears
after radiation exposure.38 It may be that we are
just reachingthe critical period in the post-radiation observations.
Marshallese populations which might be indica-
tive of aging and/or radiation exposure. The
studies reported here include measuringtransformation and replication of circulating lymphocytes
from phytohemagglutinin (PHA) stimulation in
SOMESTUDIES OF IMMUNOLOGICAL ASPECTS OF
AGING AND FALLOUT RADIATION EXPOSURE
culture, quantification of the various serum pro-
teins by electrophoresis, immunodiffusion studies
for immunoglobulin levels, and routine enumeration of peripheral blood elements. [a contrast to
results of previous studies, some of the present
tests showed differences between the exposed and
unexposed groups that might be interpreted as
radiation effects. Therefore the results on the unexposed population are treated separately here in
order to determine the correlation ofthese criteria
with aging in a normal Marshallese population.
The results on the exposed group are comparéd
with those on the unexposed group to evaluate
possible radiation effects.
Among the manv studies on the Rongelap
people, the investigation of the possibility that
radiation causes premature aging has been of continuing interest, particularly because such findings
have been reported in irradiated animals.49 The
200 unexposed Marshallese people have served as
an excellent comparison population for these
studies since they are closely related and live in
the same environment. For agingstudies, during
physical examinations measurements were made
on characteristics considered to be criteria of
aging.49 Among these were skin elasticity and
looseness and hair grayness; accommodation,
visual acuity, and arcussenilis of the eyes; hearing
loss; nerve and neuromuscularfunction, vibratory
Materials and Methods
sense, and handstrength; responseto light extinc-
In Table 15 the numbers of subjects on whom
the various tests were done arelisted according
to age decades.
tion test and rapid movement test; systolic blood
pressure; and levels of blood cholesterol and body
potassium (49K). Most of these criteria showed
Lymphocyte Cultures.
varying degrees of correlation with age and afforded a meansofarriving at a “biological age”
Blood cultures were set
up as follows. The buffy coat was separated from
5 ml of heparinized blood by sedimentation and
centrifugat.on. The culture medium consisted of
Eagle’s minimum essential medium supplemented
score for each individual. However, none of the
tests showed anysignificant indication of prema-
Table 15
Numbers of Marshallese Subjects Tested in Various Studies
(Since the results for males and females showed nosignificant difference, they were combined)
Age
group
Lymphocyte
transformation (1968)
——_—_-___—_-_~
Unexposed Exposed
Serum
proteins (1968)
—
Unexposed Exposed
Immunoglobulins (1968)
—_________—_—
Unexposed Exposed
13-20
21-30
31-40
11
11
25
11
9
10
12
11
26
1]
10
10
6
9
9
41-50
19
4
19
4
11
61-70
12
3
12
3
12
51-60
15
71-80
9
Total
102
6
l
44
17
8
105
6
l
45
—_—_—_—-——
Unexposed Exposed
4
2
2
29
16
20
{5
7
7
2
11
8
2
11
3
16
98
11
3
7
|
65
Blood
elements (1967)
3
6
5
1
46