-hDuring the first 8 months after their return to Rongelap their body burdens of Cesium!37 are estimated to have increased by factors up to 100 (resulting in a mean body burden of 0.68uc); Zinc®5 is estimated to have shown a concomitant increase (mean body burden of 0.36c). Strontium?0 showed about a twenty-fold increased rate of excretion in the urine. Only one sample of bone is available for estimating the body burden of Strontium?. ‘This is froma Rongelap man who died in April 1958 (nine months after his return to Rongelap) which showed 3.6p.po/Sr/gm Calcium (Strontium units). On the basis of North American data it is expected that the values for children would be higher. Based on preliminary analysis of data from the most recent survey period, 8 to 20 months after return to Rongelap, it appears that the people have begun to attain an equilibrium with their lightly contaminated environment. The Cesium)37 igvels appear to be slightly lower than the year before, while the Zinc? has increased slightly. The Strontium?© analyses, unfortunately, are not available yet. The body burdens estimated above are far below the ma: permissible levels; Cesiuml37 is about 2% of the MPL, and Zinc©> 1% of the MPL. In summery, a medical survey of the Marshallese people in March 1959, five years after exposure to fallout radiation, showed that the people had recovered from the acute effects of their radiation exposure and appeared to be generally in good health. The following specific statements can be made in regard to their radiation health status: 1. No illnesses or diseases were found that could be directly associated with acute radiation effects. 2. Ome case of cancer and three deaths have occurred, but with no direct relation to radiation effects. 3. Fertility does not appear to have been affected. The incidence of miscarriages and stillbirths appears to be somewhat higher than in the unexposed Marshallese, but a deficiency of vital statistics precludes definite conclusions as to whether or not this is a radiation effect. 4. Suggestive evidence of slight lag in growth and devel- opment of exposed children noted previously is being re-evaluated on the basis of better age data obtained during the past survey. 5. Blood platelet levels are within the normal range but somewhat below that for the unexposed population. [O0418d