10
Dental Survey ‘[ntra-oral examinations were
conducted as paseef the physical examination. All
patients were examined with mouth mirror and
explorer. Illumination was bv standard operating
light. Salivary pH was taken by use of pHydrion
Tabie |
Age Distribution in Rongelap Adult Populauon, 1959,
Used in Aging Study
on all subjects who were not eating candyor any
other foodstuff. Saliva samples were collected from
these patients at the time £H 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 who were in the
physical examination group: anda
mberof
children at Utirik.
Studies of Aging Criteria
Although the exposed group has shown no outward evidence visible by gross observation of anv
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
and different age groups.
This study was hampered by the sma!l number
of people involved and the lack of vital statistics on
the Marshallese people. Another difficulty has
been the uncertaintyof exact ages in somecases,
particularly in older people.
Data on aging criteria were recorded onlv on
adults 20 years of age and over. Ofthe 126 adults,
+2 were in the originally exposed group and 84 in
the larger comparison population. Table { shows
the age and sex distribution. The ages were reasdnably well 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 only a small number
of the possible ones. They were selected witha
Ex posed
Unexposed
Age. vr
Nf
F
MI
F
Mi O4
24-29
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1
12
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2
0
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6
3
3
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3
7
14
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£5 9
85-69
FOF 4
79-79
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3
3
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3
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Total
13
13
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5
125
view toward ease of assessment during routine
physical examination under field conditions, time
.
.
.
.
:
limitations, and language barrier. Therefore, unfortunately, tests of vigor and functional capacity
were necessarily limited.*
Of the 15 criteria selected, 9 were measured
directly and 6 were estumated on a 0 through ++
scale. Five tests involved the integument: (1) skin
looseness, (2) skin elasticity (retraction time), (3)
senile changes in the skin, (4) greying of the hair.
and (3) baldness. Four tests involved the special
sense organs: (1) accommodation, (2) visual acuity,
(3) arcus senilis, and (4) hearing. The cardio-
vascular system was tested by(1) systolic and (2)
chastohe blood pressure recordings, (3) peripheral
arteriosclerosis, and (+) retinal arteriosclerosis.
‘Lhere was one test of neuromuscular Function.
Vigor was measured by hand strength measurements. The test methods are described below.
Integument.
A special skin caliper was designed for measuring skin looseness and elasticity
(Figure 8). The legs of the caliper can be opened
to any desired degree up to 5 cmon scale A byadjusting screw 8. The spring tension when the caliper is closed on a fold of skin results in a pressure
of about 500 g. The inner and outer surfaces of the
legs are calibrated in millimeter markings (C).
"Severa. tests, such as pulse and blood pressure response to 4
tweestep test and vital capacity, were tried bur not used because
thes proved unsatisfactory
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