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and hand for bone developmentstudies); studies
of aging criteria; special examinationsof the skin
with color photographyof selected lesions; oph-
thalmological studies includingslit-lamp observa-
tions, visual acuity, and accommodation; audiometric examinations; cardiovascular survey; and
x-ray examinations as deemed necessary.
In 1959, 96 exposed people, including their
children, and 166 unexposed people were examined on Rongelap.
Cardiovascular Survey. In view of the possible
association oflate effects of radiation with cardiovascular disease, the following cardiovascular survey was carried out.
1. Clinical histories recorded present and past
health and illnesses, especially cadiac and pulmonary symptoms.
2. Physical examinations included the usual observations in the cardiovascular system in regard to
the rhythm andrate of the heart; the nature of the
heart sounds and murmurs,if present: the size and
shape of the heart by clinical indications; changes
in the arterial walls as observed by inspection of
the retinal arteries and by palpation ofthe radial,
brachial, and dorsalis pedis arteries; and the ap-
pearanceofthe veins.
3. Instrumental procedures: Systolic and dtastolie
blood pressures were obtained with the cuff-type
aeronoid sphygmomanometer. Oscillometry readings were obtained from bothlegsat calf level by
the Collins type of oscillometer. The highest of the
readings obtainedatdifferent pressure levels was
used as a single reading for each subject. Electrocardiograms were taken on people 20 years of age
and over (84 unexposed and 38 exposed individuals). The electrocardiograms were taken by a
Sanborn Direct Writing apparatus which had
been specially shock mountedfor field use.* In almost all subjects the electrocardiograms were
taken with 12 leads, to include three standard bi-
polar limb leads, three augmented unipolar limb
leads, and six unipolar or V chest leads in accord
with the standard 12-lead procedure recommended
by the American Heart Association. The technical quality of the electrocardiogram was in most
instances relatively good, but there were two
handicaps. The electric powerfor the instruments
was obtained from a generator on the LST by running a cable a: hore to outlets in the various build-
*Weare most grateful to the Medical Equipment Research
Department, U.S. Army, Fort Totten, N.Y., for use of this instru-
ment on a permanent loan basis.
ings used for the medical examinations. Induction
currents often caused interference, and grounding
of the instruments at times was difficult. There
were also technical variations because of variable
line voltage and amperage. X-rayfilms of the chest
were taken on selected subjects when indicated.
The number taken was kept to a minimum to
avoid additional!radiation of the exposed people,
even though the dose involved was extremely
small. The films were used chiefly for the study of
the lungs and, to some extent, for measurement of
heart size and shape. Chest films were obtained on
11 subjects in the unexposed group and 7 in the
exposed group.
It shovld be pointed out that there was no
standardized basal or adjusted level of physical
activity, such as resting for one hour before taking
the tests. The patients were seen in the course of
the usual examination, as might occurin the outpatient department of a hospital.
Arthritis Survey.
During the course of other
studies on the Rongelap population, it was pos-
sible to obtain information on the prevalence of
arthritis and allied phenomena. Since little is
knownof the prevalence of these diseases in tropical populations, any such data would be a contribution to the ‘geographic pathology” of the
arthritides’ besides being of interest in connection
with the possible adverse influence of radiation exposure on degenerative diseases.
X-rays of the hands and wrists were graded for
osteoarthritis on a scale of 14+ to 4+ by the
method of Kellgren and Laurence® as modified by
Blumberg et al.” The same x-rays were used to
detect any cases of rheumatoid arthritis, other
arthritides, or bony abnormalities.* A smallaliquot of serum (0.3 to 0.5 ml) was used to deter-
mine the presence of“rheumatoid factor” by the
bentonite flocculation test of Bozicevich et al.'° In
this test, a titer of ‘42 or greater is considered posi-
tive, 46 doubtful, and any titer below “6 negative.* A joint examination on each of the Rongelapese was performed by the medical examiners,
and anyindividual with significantjoint findings
was re-examined by one of the physicians experienced in the diagnosis ofjoint disease. Treatment
of the joint disease was undertaken where indicated.
*We are indebted to the following personnel of the National
Institutes of Health: Drs. R.L. Black, J.j. Bunim, and E.G.L.
Bywaters for reviewing the x-rays; and Dr. K. Bloch for performing the bentonite flocculation test.