PREFACE Perhaps the most important step in any organized scientific effort is the periodic review and evaluation of the known and the unknown aspects of a problem. Identification and acknowledgment of relationships and consideration of alternative courses of investigation are extremely important steps in attempt to reach solutions to a problem; or, at best, to gain information and guidance for moving out into the unknown. The Nevada Applied Ecology Group Symposium on the Dynamics of Transuranics in Terrestrial and Aquatic Environments was held in October, 1976, at Gatlinburg, Tennessee. The symposium was planned to bring about a concerted review and evaluation of the current status of a major environmental problem and the associated body of information available to investigators involved in studies of environmental transurauics. Papers selected for publication in this document are coauthored by scientists and other technical and professional people from several national laboratories, academic institutions, private corporations, and government agencies. It is recognized that not all aspects of environmental transuranics are covered in this publication. Reports by M. Wahlgren, Argonne National Laboratory (read by J. Alberts, ANL), and J. Pinder, Savannah River Ecology Laboratory, were not received for publication, and a report by A. L. Boni and R. W. Taylor, SRL, E.I. DuPont, "Plutonium Isotope Distribution in U.S. Surface Waters," was not cleared for publication. It is hoped that those areas of environmental transuranics research not presented in this document will be included in publications currently underway or planned by other research groups. An addition to environmental transuranics literature since the Gatlinburg symposium was the two-volume NEVADA APPLIED ECOLOGY GROUP PROCEDURES HANDBOOK FOR ENVIRONMENTAL TRANSURANICS, NVO-166. The NAEG procedures handbook (dated October, 1976, released in May, 1977) includes most of the NAEG standard procedures used in applied environmental plutonium and other transuranics sampling at the Nevada Test Site, with related laboratory and statistical procedures. The handbook is available from the National Technical Information Services, NTIS, Springfield, Virginia. nS —_——— Our gratitude is extended to the symposium authors and participants; to arrangements personnel (ORNL); to the headquarters, field, and laboratory people who encouraged and contributed to the symposium, especially Gordon Facer, HQ ERDA/DMA; Mahlon E. Gates, Manager, ERDA/NV; Roger Ray, Assistant Manager for Environment and Safety, ERDA/NV; Henry B. Gayle, Paul G. Noblitt, Timothy M. Catt, and the Word Processing Center, Holmes & Narver, Inc., Las Vegas; Winnie Howard and Don L. Wireman, NAEG staff; and to certain "senior" scientists who shared with the participants their perspective of many years, J. Newell Stannard, Eugene van der Smissen, and Eric B. Fowler.