[Illustration: THE AUTHOR NEAL O. HINES is an established writer and experienced academic administrator with an unusual background in radiobiological surveys of the Pacific Ocean atomic test sites. He holds degrees from Indiana and Northwestern Universities. A former journalism teacher at the University of California and Assistant to the President of the University of Washington, Mr. Hines also worked for a number of years with the Laboratory of Radiation Biology of the University of Washington, where he served from 1961-1963 as administrative assistant and as Executive Secretary of the Advisory Council on Nuclear Energy and Radiation for the State of Washington. He was a member of the survey teams visiting Bikini and Eniwetok in 1949 and 1956 and Christmas Island in 1962. His “Bikini Report” (_Scientific Monthly_, February 1951) was one of the earliest descriptions of radiobiological studies in the Pacific. He is the author of _Proving Ground_ (University of Washington Press, 1962), a detailed history of radiobiological studies in the Pacific from 1946-1961.] ATOMS, NATURE, and MAN Man-made Radioactivity in the Environment By NEAL O. HINES INTRODUCTION Mankind, increasingly crowding the earth, modifies the earthly environment in uncounted subtle and unpredictable ways, too rarely to the benefit of either earth or man. In this century it has become critically important that we comprehend more precisely than ever before the biological mechanisms and balances of our environment and that we learn to detect changes and to understand what they imply. The release of atomic energy added a new dimension to the possibility of environmental change. In man’s first experiments with atomic energy, he added small but perceptible amounts of radioactivity to the earth’s natural total; as the Atomic Age matures, he inevitably will add more. But, in the course of his experiments, man has come to realize that environmental and biological studies, which now are necessary because of the use of atomic energy, may help solve not only the problems atomic energy creates but also the larger problem of how to manage wisely the world’s limited natural resources. This booklet describes the environmental investigations that have been conducted with the aid of the atom since the first atomic detonation near Alamogordo, New Mexico, in 1945. The earth’s mysteries, however, are not easily unlocked, and investigations of our environment with atomic tools have only begun. The story thus is one of beginnings—but of beginnings that point the way, it is hoped, to a new understanding of the world in the atomic future. SOME PRELIMINARY IDEAS