18 Eniwetok Test Site have been due to radiation effects. Indeed, the same "abnormalities" have been found in areas not subject to radioactive contamination. Consequently, studies aimed specifi- cally at the determination of radiation effects can best be done under controlled laboratory conditions. The emphasis at Rongelap Atoll has therefore been on mineral transport through the biota. This requires evaluation of the stable isotopes as well as the radioisotopes. The efforts of the first year have been concentrated on the land forms; however, collection and analysis of marine organisms have been made to provide a continuous record of radiation levels in different life forms. The marine phase is to be expanded during the coming year to include more extensive sampling of the lagoon bottom and waters. None of the studies can be considered complete now or for some time to come. thus l. Some of the points that stand out most clearly far are as follows: The general levels of radioactivity continue to decline more rapidly than would be expected from physical decay alone (there are certain exceptions such as the levels of sr?° in coconut crabs). 2. Extensive sampling of soils shows clearly that the radioiso- topes remain concentrated in the top inch or less. 3. Radioactive materials are found more uniformly mixed to aj depth of several inches in lagoon sediments.