SECTIONIll. GENERAL EVALUATIONS The decision to conduct nuclear weapons tests for the defense of our country was made at the highest level of our Government. The Atomic Energy Commission was charged with the responsibility for carrying out the program. The AEC sought and followed the best advice both from within and outside the Government in the conduct of new and potentially hazardous operations. The record, as summarized above, must speak for itself as to potential risks incurred to the public in the fulfillment of a mission essential to national security, Of all the health aspects of nuclear weaponstesting, that of radiation exposure has received the greatest attention. If, as the data and their evaluation given above indicate, there has been a relatively low degree of risk associated with past atmospheric tests (except for the fallout on the Marshallese and the Japanese fishermen), then why has there been so much concern expressed? There are probably several reasons. First, whereas the potential radiation exposures are only a very small fraction of those received from natural background sources, they are, of course, additional amounts. Second, in the absenceof positive proof otherwise the prudent assumption is accepted that for every small increment of radiation exposure there is a corresponding increment of bio- logical effect (“linear” concept)—rather than the “threshold” concept where a certain total radiation dose must be received before irreparable damage occurs. Based on this and other assumptions, admissible theoretical calculations can be made as to the potential number of genetic mutations, of cases of leukemia, etc. that could result from fallout. This linear concept leads axiomatically to the situation of there being no sharp dividing line below which there is complete safety and above which there is a serious hazard. Radiation protection guides, therefore, must be derived on some additional basis, as noted next. Third, there has been some misinterpretation of the radiation protection guides. The use of the linear concept leaves little choice for deriving radiation protection guides,i.e. —there must be a balancing of the “benefits” anticipated from any atomic energy program, whether it be for normal peacetime 31