10
Dental Survey. Intra-oral examinations were
conducted as part of the physical examination.All
patients were examined with mouth mirror and
explorer. Ilumination was by standard operating
light. Salivary pH was taken by use ofpHydrion
on all subjects who were not eating candyor any
other foodstuff. Saliva samples were collected from
these patients at the time pH determinations were
made. Intra-oral radiograms were not available.
Dental examinations were carried out on thefollowing groups: 30 children at Majuro; all the
adults.and children at Rongelap whowerein the
physical examination group; and a numberof
children at Utirik.
Studies of Aging Criteria
Although the exposed group has shown no outward evidence visible by gross observation of any
accelerated aging effect of radiation, it was
thought desirable to have available measurable
criteria of possible age changesfor use during normal physical examination. Therefore the over-all
objective of this study was to establish tests to
evaluate any possible radiation-induced senescence in the exposed group compared with the unexposed population living on the same island.
However, the data (presented in a later section on
results) collected during the 1959 survey (5 years
after exposure) showed no apparent differences
between the exposed and unexposed groups.
Therefore the data from the two groups have been
pooled with the objectives of presenting the methodology, indicating the trend of changes with age
of the various aging criteria chosen, and attempting
to determine a biological age score for individuals
anddifferent age groups.
This study was hampered bythe smal! number
of people involved and the lack of vital statistics on
the Marshallese people. Another difficulty has
been the uncertainty of exact ages in some cases,
particularlyin older people.
Data on aging criteria were recorded only on
adults 20 years of age and over. Of the 126 adults,
42 were in the originally exposed group and 84 in
the larger comparison population. Table 1 shows
the age and sex distribution. The ages were reason-
ablywell distributed except for a smaller number
of older people (> 60 years of age).
The age criteria chosen were based on changes
generally believed to be associated with physiological senescence and represent onlya small number
of the possible ones. Theywere selected witha
Table 1
Age Distribution in Rongelap Adult Population, 1959,
Used in Aging Study
Exposed
Unexposed
Age, yr
M
F
M
F
20-24
25-29
30-34
35-39
40-44
45-49
90-54
55-59
60-64
65-69
70-74
75-79
>80
0
2
3
1
4
1
1
2
0
0
1
0
2
5
1
2
4
2
0
0
I
6
0
2
1
1
1
12
3
4
6
2
5
3
5
2
0
0
2
6
6
5
4
3
3
5
1
3
3
0
0
0
Total
12
21
13
13
15
6
MH
7
14
3
3
1
5
126
DOE ARCHIVES”
view toward ease of assessment during routine
physical examination underfield conditions, time
limitations, and Janguagebarrier. Therefore, unfortunately, tests of vigor and functional capacity
were necessarily limited. *
Of the 15 criteria selected, 9 were measured
directly and 6 wereestimated on a 0 through 4+
scale. Five tests involved the integument: (1) skin
looseness, (2) skin elasticity (retraction time), (3)
senile changesin the skin, (4) greying ofthe hair,
and (5) baldness. Four tests involved the special
sense organs: {1) accommodation, (2) visual acuity,
(3) arcus senilis, and (4) hearing. The cardiovascular system was tested by(1) systolic and (2)
diastolic blood pressure recordings, (3) peripheral
arteriosclerosis, and (4) retinal arteriosclerosis.
There was one test of neuromuscular function.
Vigor was measured by hand strength measurements. The test methods are described below.
Infegument.
A special skin caliper was de-
signed for measuring skin looseness andelasticity
(Figure 8). The legs of the caliper can be opened
to anydesired degree up to 5 cm on scale A byadjusting screw B. The spring tension whenthecaliper is closed on a fold of skin results in a pressure
of about 500 g. The inner and outer surfaces of the .
Jegs are calibrated in millimeter markings (C).
*Several tests, such as pulse and blood pressure response to a
two-step test and vital capacity, were tied but not used because
they proved unsatisfactory.