50 types.®7 For the three major pathogensfound,the overall infection rates were: Entamoeba histolytica, 18.2%; hookworm, 5.5%; and Trichurts trichiura, 34.3%. Eosinophilia (>> 5%) has consistently been noted in about half the people. The fact that half the cases with eosinophilia showed no helminthic infections at all suggests that other factors besides parasitic infections must be responsible. The eosinophilia mayberelated to chronic fungus and otherinfections, particularly of the skin. Complementfixation studies for parainfluenza 1, 2, and3, respiratory syncitial, psittacosis, and Q fever showed antibodiesto all groups of viruses except that for Asian influenza, which probably had not yet seriously involved the people of the Marshall Islands. The antibodytiters appeared to be somewhatlowerin the exposed people. Immunoelectrophoretic analysis showed neither a paraproteinemia nora typical picture of antibody- deficiency syndrome, but a high frequencyof in- creases of some of the immunoglobulins was noted. Blood volume studies with 51Cr-labeled sodium chromate showed a significant reduction in red cell mass and/or plasma volume. However, there is some indication that Americansliving in the Islands for more than | year mayalso haveslightly lowered values. Tritiated water has been used to establish the relationship of blood volume to lean body mass. Acknowledgments The cooperation of many agencies and persons was necessary to carry out these surveys successfully. The authors are deeply grateful for valuable assistance to manyindividuals too numerousto name. Weare particularly grateful to the people of Rongelap and Utirik Atolls for their cooperation in these examinations. Manyofficials of the Atomic Energy Commission, particularly Dr. John R. Totter and Dr. H.D. Bruner and their staff of the Division of Biology and Medicine, and Mr. W.A. Bonnet and Mr. W.Streenanof the Honolulu Operations Office, were most helpful in coordination of arrangements and in supporting the surveys in every way possible. Weare grateful to the officials of the Departmentof the Interior, particularly Mrs. Ruth Van Cleeve and Mrs. Elizabeth Farrington, and the officials of the Trust Territory of the Pacific Is- lands, including High Commissioners Mr. E.E. Johnston and Mr. W.R. Norwood; the Director of MedicalServices, Dr. W.M. Peck; the District Administrator for the Marshall Islands, Mr. Robert Law; the Director of the Majuro Hospital, Dr. John Iaman, and members ofhis staff; the Trust Territory Representative at Kwajalein, Mr. W.M. Ownby, and Dr. Ezra Riklon at the Ebeye Hospital; all were most helpful. The Pacific Missile Range Facility at Kwajalein wasof great assistance in furnishing necessary airlifts and materials. Mr. Frank Granich and others of Global Associates at Kwajalein, Dr. ¥.C. Smith at the Kwajalein Hospital, and Colonel D.B. Milar, Commanding Officer, were extremely helpful. At Brookhaven National Laboratory, contribu- tions were made by manyindividuals in many departments, including Medical, Instrumentation and Health Physics, Photography and Graphic Arts, the Shipping Section, and others. We are grateful to the following people at BNL for their support and advice: Dr. Maurice Goldhaber, Di- * rector; Dr. V.P. Bond, Associate Director; Dr. J.B.H. Kuper, Chairman of the Instrumentation and Health Physics Department; Dr. E.P. Cronkite, Chairman of the Medical Department, and others in his Department, including Drs. D.D. Van Slyke, J.S. Robertson, and S. Cohn, and Messrs. A. Finn, G. Jackson, and W. J, Walsh. We appreciate the assistance in statistical analyses given by Mr. Keith Thompson. In regard to advice and consultation on the thyroid pathology in the Marshallese, we are in- debted to Drs. 8. Warren and W.A. Meissner of the New England Deaconess Hospital; Dr. B.P. Colcock, Lahey Clinic; and Drs. L.K. Dahl, H.L. Atkins, and H.A. Johnson of Brookhaven National Laboratory. Weare particularly grateful to the nursingstaff here for their kindness and excellent care given the Marshallese thyroid cases. Wewishalso to thank Mrs. J. Redzinak for her devoted secretarial assistance, and Mrs. M. Dienes for her editorial help. References 1. Cronxrre, E.P. et av., The Effects of lonizing Radiation on Human Beings: A Report on the Marshallese and Americans Accidentally Exposed to Radiation Fallout anda Di1scussion ofRadiation Injury in the Human Being, AEC-TID 5358, U.S. GovernmentPrinting Office, Washington, D.C., 1956.