- 3- Recovery of the blood-forming tissues is judged virtually complete according to studies of the peripheral blood counts. A possible exception is seen in the blood platelets which are slightly below the levels in the unexposed group but still within the normal range. There is no evidence of any untoward effect associated with this finding. The beta burns of the skin healed rapidly during the first few months after exposure. In 12 cases there remain slight scarring of the skin and pigment change at the former site of deeper burns. However, no evidence of any cancerous change in these scars is noted. In those that lost hair, regrowth of normal hair was complete by six months after exposure. Very little is known about late effects of radiation in human beings. Increased incidence of leukemia in the exposed Japanese people has been noted and, in animal studies, the following late effects of radiation may result: life shortening, premature aging, increase in degenerative diseases, increased incidence of malignancies, opacities of the lens of the eyes, and genetic changes. The Marshallese have been carefully examined for evidences of such changes, but none have been seen. Radiation-induced leukemia is known to appear relatively soon after exposure and other types of malignancy at later times. Therefore, continued examinations are essential in order to detect and, if possible, treat such effects should they develop. The radioactive fission products that had been absorbed internally by the Rongelap people were never sufficient in amount to result in acute effects. These radioactive materials were excreted rapidly during the first six months after exposure. The island of Rongelap remains slightly radioactively contaminated but careful surveys showed the island to be safe for habitation by the summer of 1957 when the people were returned to Rongelap. Studies of the body burdens of radioactive materials in these people is an important part of the medical surveys. A 21 ton steel room with very sensitive radiation detecting equipment has been used in the past 2 annual surveys at Rongelap to determine the body burdens of radionuclides. In addition numerous urine samples have been analyzed for radioactivity. The results of these studies show that there has been an increase in body burdens, principally of Cesium137, Zinc©5 and Strontium? » since their return to Rongelap. About the same levels of these isotopes have been noted in those exposed and unexposed. 1004183