PARTICIPANTS Austin M. Brues, Co-Chairman Division of Biological and Medical Research Argonne National Laboratory Argonne, Illinois Arthur C, Upton, Co-Chairman Biology Division Oak Ridge National Laboratory Oak Ridge, Tenneasce Robert U. Ayres Hudson Institute, Ine. Croton-on-Hudson, New York Leo K, Bustad Radiobiology Laboratory University of California Davia, Califorma George W, Casarett Department of Radiation Biology and Biophysics University of Rochester School of Medicine and Dentistry Rochester, New York. Robert A. Conard . Medical Research Center Brookhaven National Laboratecry Upton, Leung Island, New York Jelle de Boer Department of Radiation Hiclogy United States Air Force Kirtland AFB, New Mexico R. Lowry Dobson ’ Bio- Medical Division lawrence Radiation Laboratory University of California Livermore, California Lauren R. Donaldson College of Fisherics University of Washington Seattle, Washington Charles L. Dunham Division of Medical Sciences National Research Council National Academy of Sciences Washington, D.C. Merril Eisenbud Department of Environmental Medicine New York University Medical Center New York City, New York John V..Hemler, Lec USA Office of the Deputy Director (Scientifics Defense Atomic Support Agency Washington, D.C,