9 and hand for bone developmentstudies); studies of aging criteria; special examinationsof the skin with color photographyofselected lesions; ophthalmological studies including slit-lamp observations, visual acuity, and accommodation; audio- metric 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 cardiovasculardisease, the following cardiovascular survey was carried out. A. 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 palpationofthe radial, brachial, and dorsalis pedis arteries; and the appearanceofthe veins. 3. Instrumental procedures: Systoltc and diastolic blood pressures were obtained with the cuff-type aeronoid sphygmomanometer. Oscillometry read- ings were obtained from bothlegsat calf level by the Collins type of oscillometer. The highest of the readings obtained at different 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 mountedforfield use.* In almost all subjects the electrocardiograms were taken with 12 leads, to include three standardbi- polar limb leads, three augmented unipolar limb leads, andsix 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. Theelectric power for the instruments was obtained from a generator on the LST by running a cable ashore to outlets in the various build*Weare most grateful to the Medical Equipment Research 2 06% Ca con cri Department, U.S. Army, Fort Totten, N.Y., for use of this instrument on a permanentloan 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 measurementof heart size and shape. Chest films were obtained on 11 subjects in the unexposed group and in the exposed group. It should be pointed out that there was no standardized basal or adjusted level of physical activity, such as resting for one hourbefore taking the tests. The patients were seen in the course of the usual examination, as might occur in the outpatient departmentofa 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. Sincelittle 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 influenceof radiation exposure on degenerative diseases. X-rays of the hands and wrists were gradedfor osteoarthritis on a scale of 1+ 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 small aliquot of serum (0.3 to 0.5 ml) was used to determine 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 positive, 46 doubtful, and any titer below 6 nega- tive.* A joint examination on each of the Rongelapese was performed by the medical examiners, and anyindividual with significantjoint findings was re-examined by oneof the physicians experienced in the diagnosis ofjoint disease. Treatment of the joint disease was undertaken whereindicated. *Weare indebtedto the following personne! of the National Institutes of Heaith: 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 flocculationtest.