3 presentat the time of exposure, whodied 2 years radiation of the skin were seen in 12 cases which ease complicating diabetes; and (3) a 36-year-old scarring, and atrophy at thesite of the former burns. Numeroushistopathological studies have after the accident; (2) a 78-year-old man who died, 3 years after exposure, of coronary heart disman whodied of acute varicella, 4 years after ex- showed varying degrees of pigment aberrations, been made,''"* and the changes found have been posure, who hadreceived only 69 r, having been on Ailingnaeat the timeofthe fallout. There was no apparentrelationship between any of these deaths and radiation exposure, and mortality in consistent with radiation damage. At no time have changes been observedeither grossly or microscop- than in the unexposed population. It was difficult to evaluate the effects on fertility. after exposure and complete regrowth of normal hair by six months. No further evidenceofepilation has been seen. the exposed group did not appearto be greater However, a numberof apparently normal babies ically indicative of malignant or premalignant change. Spotty epilation on the heads was short lived, regrowth of hair occurring about 3 months were born during the 4-year period, and there has been no discernible fall in birth rate. A slightly higher numberof miscarriages occurred in the exposed women than in the unexposed group; this will be further evaluated in the present report. No of the people, beginning about 3 weeks after exposure. By 6 months, this pigmentation had largely been found that could be related to radiation. Studies on height, weight, and bone age seemed most cases. The cause of this phenomenonhas not been explained. opacities of the lens or other eye changes have to show slight degree of retardation in growth and developmentin the exposed children. How- An interesting observation was the appearance of a bluish-brown pigmentation of the semilunar areas of the fingernails and toenails in about 90% grown out with the nail and had disappeared in ever, the small number of children involved, and INTERNAL IRRADIATION dren were in doubt, has resulted in a re-evaluation Radiochemical analyses of numerous urine samples of the exposed population showedinternal a later finding that exact ages of some ofthe chil- of these data based on morereliable age determinations. BETA IRRADIATION OF THE SKIN It was impossible to get an accurate estimate of the radiation dose to the skin. Beta burnsof the skin and epilation appeared about 2 weeksafter exposure, largely on parts of the body not covered by clothing, About 90% of the people had these burns, and a smaller number developed spotty epilation of the scalp. Most of the lesions were superficial; they exhibited pigmentation and dry, scaly desquamation, and were associated with little pain. Rapid healing and repigmentation followed. Some lesions were deeper, showed wet desquamation, and were more painful. A few burns becamesecondarily infected and had to be treated with antibiotics. Repigmentation of the lesions gradually took place in most instances, and the skin appeared normal within a few weeks. However, in about 15% of the people, deeper lesions, particularly noted on the dorsum ofthe feet, continued to show lack of repigmentation with varying degrees of scarring and atrophyof Mm a! cD co" ary cD os the skin. At 4 years the only residual effects of beta absorption of radioactive materials, probably brought aboutlargely through eating and drinking contaminated food and water andto a lesser extent through inhalation. During thefirst few days when the bodylevels were at their highest, the maximum permissible concentrations were approachedorslightly exceeded only in the case of strontium-89 and the isotopes of iodine. The concentrations were believed to be too lowto result in any seriouseffects. Bodylevels fell rapidly, so that by 2 and 3 years post exposure, they were far below the accepted maximum permissible level; by 6 monthsactivity in the urine was barely detectable. The return of the Rongelapese to their home island (which after careful survey was considered safe for habitation, despite a persisting low level of radioactive contamination) wasreflected in a rise in their body burdens and increased urinary excretion of certain radionuclides. Beginning in 1957, gammaspectroscopybyuse of a low-level counting chamber was addedto the techniques of radiochemicalanalysis. This, along with radiochemical analysis of urine samples, showed an increase in body burdensof cesium-137 by factors of up to 100 and of strontium-90 by a factor of 10 to 20; and someincrease also in zinc-65, since the re-