Bioenvironmental studies form a background against which all atomic energy research is conducted. The central objective of the Atomic Energy Commission’s environmental radiation studies is “to determine the fate and effect of radionuclides in the environment”. This objective calls for hundreds of concurrent approaches to the interlocking problems of the air, the sea, and the land. The AEC alone, through its Division of Biology and Medicine, is supporting research costing about $75 million a year, about two-thirds of this amount going to biological and medical programs at AEC laboratories and the remainder to some 650 individual contract studies at universities, nonprofit institutions, and commercial research organizations. Additional programs, large and small, are supported by foundations or other agencies. Work goes on in other nations. Many programs are international. Although only a fraction of this total activity is specifically related to environmental problems, the concern throughout is with the effect, for good or ill, of radioactivity on man and his world. It is possible to suggest by example the lines of inquiry. [Illustration: _A University of Georgia Research Institute ecologist studying biological specimens in a controlled environment near the AEC Savannah River Plant, Aiken, South Carolina._] The Trinity site in New Mexico, scene of the first atomic detonation in history, was studied for a number of years after 1945, particularly in relation to the distribution and effects of residual radioactivity in the desert environment. In 1963 and 1964 scientists from the University of Missouri undertook to determine the state of revegetation of the original atomic bomb crater. The Nevada Test Site, where nuclear programs have been conducted for a decade and a half, has invited investigations of revegetation. Project Sedan, an underground thermonuclear detonation in 1962, established conditions for one such study. The crater produced by this detonation was 320 feet deep and 1200 feet in diameter. Vegetation growing within 2500 feet of ground zero was almost completely destroyed, and the original soil was covered by radioactive throwout. Shrubs as far as 5000 feet away from ground zero were damaged by air blast, and, in the weeks after the detonation, plants within a two-mile radius were covered by radioactive sand and silt or by deposits of windblown radioactive dust.