“opm 4 ‘ . stat SR ; ’ Pee BULLETIN OF THE TORREY BOTANICAL Vou. 91, No. 4, pp. 283-323 CLUB Juty-AuGustT 1964 Radioecology and the study of environmental radiation William E. Martin? Laboratory of Nuclear Medicine and Radiation Biology of the Department of Biophysics and Nuclear Medicine, University of California, Los Angeles Martin, W. E. (Lab, of Nuclear Medicine and Radiation Biology, Dept. of Biophysics, Univ. of Calif., Los Angeles) SRadioecology and the study of environmental radiation. Bull. Torrey Bot. Club 91: 283-323, 1964-—Among the major scientific problems of the Nuclear Age are those which deal with the collection of data and the development of concepts to be used in making realistic, quantitative evaluations of the biologieal hazards, if any, resulting from increased environmental radiation due to fallout. This paper presents a brief review of some of the ecological aspects of these problems. The major topics considered are: (a) the kinds and amounts of “natural” and “man-made” sources of ionizing radiation in the biosphere, (b) the formation and dispersal of fallout, including a comparison of local, tropospheric and stratospheric fallout patterns, (c) the redistribution of fallout materials by environmental processes, their accumulation by plants and animals, and their cycling in terrestrial food-chains, and (d) the evaluation of potential biological hazards arising from small increases in external and internal exposure of organisms to ionizing radiation. Radioecology can be defined as the study of organisms and their external environments in relation to ionizing radiation. As a practical application of ecology to the study of fallout and reactor effluents, radioecology is primarily concerned with: (a) the influence of ionizing radiation on plant and animal populations and communities in their natural environments and (b) the influence of organisms and environmental processes on the distribution of radioactive materials in the biosphere. Tonizing radiation has always been a part of the natural environments of living organisms. Speculations as to the possible influence of environ1 These studies were supported by Contract AT (04-1) GEN-12 between the U. 8. Atomic Energy Commission and the University of California at Los Angeles. The paper was originally presented at the Eighteenth Annual Research Conference of the Bureau of Biological Research at Rutgers University, New Jersey, April 27-28, 1962. Reeeived for publication February 12, 1964. 283