is not the same for all kinds of substances that give off radiation, but rather like the vegetation on the island had different life times. This simple demonstration also helped the people to understand why the clicking of the radiation detection instruments haa decreased so much Gver the years and that the levels measured today could be essen- ‘tially harmless. Also, this demonstration pointed out dramatically that a lot of radiation must be present to do significant harm. This was analogous to their own experience with the parasites attacking their breadfruit tree. This visual demonstra- tion, which they were aware of, concerned the effect of a small number of parasites attacking the breadfruit tree and yet permitting the tree to produce breadfruit as compared to the increase in the number of parasites attacking the tree with drastic results in the total absence of any breadfruit. The parallel to radiation effects seemed obvious in the light of the above examples. The need to develop analogies related to their daily activities and observations was constantly kept in focus. This method seemed to be the most effective way to communicate the concepts of radiation. The greatest assurance came from the demonstration that a scientist would be ready to live with them and be exposed to the same radiation as they were experiencing. This action served as the best example of the fact that there are other parts of the world where populations are being exposed daily to radiation levels exceeding 100 times their levels without significant harm. Although the latter was difficult to comprehend, since it was not a visual experience, the presence of a scientist among them lent an air of credibility to the statements. Expanded Education Program The tremendous success of this initial personal, on-site, one-on-one educational program as conducted by the senior author has prompted this Laboratory to develop an extensive educational program for the inhabitants not only of Rongelap and Utirik, but also those returning to Enewetak and Bikini. This program will adequately meet the mandate dictated by the US Congress wherein such an educational program will be conducted for the express purpose of assisting the people of Bikini, Enewetak, Rongelap and Utirik, to more fully understand nuclear radiation, to assure that unrealistic fears will be minimized and measures aimed at preventive radiation exposure will be more