33 Two deaths occurred in the exposed and one in the unexposed group since the last survey. The deaths in the exposed group did not appearto be related to radiation exposure. Diseases, infectious and noninfectious, were as common in the exposed as in the unexposed people. Nutrition appeared good except for slight hemeralopia in several children ascribed to vitamin A deficiency. The directly related to radiation effects but possibly having some bearing on prognosis. Findings in these studies were common to both the exposed and unexposed populations. An extensive intestinal parasite survey showedthatthe people were infected with many types of protozoa and helminths, although this finding did not entirely account for the generally higher incidence of Nolate effects of exposure were noted. Shortening of life span has not been observed. The death rate has been about the same.in the exposedas in eosinophilia. Among other findings that need further explanation are the general anemic tendency, the high plasmaprotein levels with increased gamma globulin, and the high levels of serum protein-bound iodines and vitamin B,,. It is hoped that some of these problems will be solved in radiation opacities of the lens or differences in Another group ofinvestigations concerned the anthropological background of the Marshallese birth rate was about the same in the exposedas in the unexposed group, and the babies appeared normal. the unexposed population. Premature aging of the irradiated group has not been grossly visible. No visual acuity have been noted. No malignancies have been observed, and the incidenceof degenerative diseases was about the same asin the un- exposed group examined. Genetic studies have not been carried out, but no difference in the inci- dence of congenital abnormalities has been noted in the first-generation children of the exposed compared with the unexposed populations. The onlyresidual effects of beta irradiation of future surveys. based on studies of genetically determinedtraits. Amongthese were determinations of various blood groups and of hemoglobin and haptoglobin types. These studies are shedding some light on the origin of these people and on the homogeneityof the population being investigated. Their blood groups resemble most closely those of people from Southeast Asia and Indonesia, and the population appearsto be relatively homogenous. the skin were seen in 12 cases which showed varving degrees of pigment abberation, scarring, and atrophyat the site of deeper burns. In no case was Acknowledgments (which has a persisting lowlevel of radioactive Because of the broad scope of the studies carried out in this survey and the complexity of the operation, the cooperation and coordination of many persons and agencies were necessary to carry out the mission successfully. The authors are deeply grateful to many individuals, too numerousto name, for their invaluable assistance and coopera- there evidence of chronic radiation dermatitis or premalignant or malignant changein thelesions. The return of the Rongelapese to their island contamination) is reflected in a rise in their body burdensand increased urinaryexcretion of certain radionuclides. Estimates of these body burdens of radionuclides were determined by gammaspec- troscopy and by radiochemical analyses of urine samples. These estimates showed that the body burden of Cs'** had increased by a factor of 100 andof Sr’® by a factor of 10, with some increase in Zn��? also, since the return to Rongelap. However, the levels were well below the accepted maximum permissible levels. Analysis of bone samples on one of the men whodied showed 3.7 Sr’? units/g calcium. Further detailed studies on the radiation ecological aspects of these surveys, including examinationsof the food and human metabolism of these isotopes, is in progress and will be an importantpartof future investigations. The survey team devoted considerable attention to other medical studies in the Marshallese not tion. Manyofficials of the Atomic Energy Commis- sion, particularly Dr. Charles L. Dunham, Dr. H.D. Bruner, and many of their staff of the Divi- sion of Biology and Medicine, as in the past, have been most helpful in the coordination of arrange- ments with the Department of Defense, Depart- ment of the Interior, Department of State, and other govermental agencies. At Brookhaven National Laboratory the high degree of interdepartmental cooperation made possible the designing and constructionofthe steel room, the assembling andtesting of complexelectronic equipment needed for the gamma spec- troscopy, and the ordering, packing, and shipping of equipment for the survey. We are particularly