radiation of the skin were seen in 12 cases which showed varying degrees of pigment aberrations, present at the time of exposure, who died 2 years after the accident; (2) a 78-year-old man who died, 3 years after exposure, of coronary heart disease complicating diabetes; and (3) a 36-year-old man whodied of acute varicella, 4 years after ex- scarring, and atrophy at the site of the former burns. Numeroushistopathological studies have been made,'** and the changes found have been posure, who had received only 69r, having been consistent with radiation damage. At no time have changes been observed either grossly or microscopically indicative of malignant or premalignant change. Spottyepilation on the heads wasshort lived, regrowth of hair occurring about 3 months after exposure and complete regrowth of normal hair by six months. No further evidenceof epilation has been seen. An interesting observation was the appearance of a bluish-brown pigmentation of the semilunar areas of the fingernails and toenails in about 90% of the people, beginning about 3 weeks after exposure. By 6 months, this pigmentation had largely grown out with the nail and had disappeared in most cases. The cause of this phenomenon has not on Ailingnaeat the time of the fallout. There was no apparent relationship between any of these deaths and radiation exposure, and mortality in the exposed group did not appearto be greater than in the unexposed population. It was difficult to evaluate the effects on fertility. However, a number of apparently normal babies 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 opacities of the lens or other eye changes have been found that could be related to radiation. Studies on height, weight, and bone age seemed been explained. to show a slight degree of retardation in growth and developmentin the exposed children. How- DOE ARCHIVES ever, the small numberof 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 of the chilof these data based on morereliable age deter- absorption of radioactive materials, probably minations. 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 weeks after 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 httle pain. Rapid healing and repigmentation followed. Somelesions 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 of the feet, continued to showlack of repigmentation with varying degrees of scarring and atrophy of the skin. At 4 years the only residual effects of beta —_— ee - brought about largely through eating and drinking contaminated food and water and to a lesser extent through inhalation. During thefirst few days when the bodylevels were at their highest, the maximum permissible concentrations were approached orslightly exceeded only tn the case of strontium-89 and the isotopes of iodine. The concentrations were believed to be too lowto result in anyserious effects. Bodylevels fell rapidly, so that by 2 and 3 years post exposure, they were far below the accepted maximum permissible level; by 6 months activity 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 lowlevel of radioactive contamination) was reflected in a rise in their body burdens and increased urinaryexcretion of certain radionuclides. Beginning in 1957, gamma spectroscopy byuse of a low-level counting chamber was addedto the techniques of radiochemical analysis. This, along with radiochemical] analysis of urine samples, showed an in- crease in body burdens of cesium-137 byfactors of up to 100 and of strontium-90 bya factor of 10 to 20; and someincrease also in zinc-65, since the re- geen gee i ee te re ee ee eer = a ee ee