During the twenty years the authors have been associated with the field of radiation ecology, there has been a diversified and increasing use of radionuclides in applied and basic biological research. Prior to the advent of the atomic age in the 1940s the use of radionuclides as tracers was initiated, and following that period one observed a dramatically increased use in many disciplines. Concurrent with this increase there appeared many books and articles on radionuclide tech niques useful to biologists in general. Although only a few ecological applications were evident in these early years, ecologists were quick to see the opportunities available in their field. In the United States, major centers for such activities included Oak Ridge National Laboratory and the U. S. Atomic Energy Com mission's Savannah River Plant. At Oak Ridge National Laboratory Dr. Stanley I. Auerbach, director of ecological activities, encouraged with remarkable suc cess the use of tracers by his associates. Dr. Eugene P. Odum had the foresight to see that radionuclide tracers provided the means to solve many problems of interest to ecologists. Consequently, his research included some unique radio tracer applications at the Savannah River Plant. In addition he encouraged others involved in ecological activities at the Savannah River Plant to do likewise. Ecologists such as Dr. Robert C. Pendleton at the U. S. Atomic Energy Com mission's Hanford Works applied radionuclides in their research. To these early investigators and to those who followed we owe the oppportunity to write this book.

It is only with the ending of the Cold War that the issue of environmental hazards at many former nuclear testing sites around the world has attracted international scientific interest. This book discusses the environmental, ecological, and health problems associated with nuclear testing. Topics treated include dose assessment, risk, speciation and transport of radionuclides, measurement and separation of radionuclides, and remedial options. The nuclear test sites examined include the Semipalatinsk Nuclear Test Site (Kazakhstan), the Nevada test Site (USA), the Pacific atolls, and the Maralinga Test Site (Australia). The volume also discusses the additional release sites of Chelyabinsk (Russia), Chernobyl (Ukraine), Palomares (Spain), Los Alamos (USA), and others. A valuable compendium of radiological problems for a wide spectrum of readers, from non-specialist to expert.

Radioactive particles have been released to the environment from a number of sources, including nuclear weapon tests, nuclear accidents and discharges from nuclear installations. Particle characteristics influence the mobility, biological uptake and effects of radionuclides, hence information on these characteristics is essential for assessing environmental impact and risks. This publication presents a series of papers covering sources and source term characterisation, methodologies for characterizing particles, and the impact of particles on the behaviour of radioactive particles in the environment. Sources covered include the Chernobyl accident, nuclear weapons accidents at Thule and Palomares accident, the discharges from Dounreay and Krashnoyarsk, and depleted uranium in Kosovo and Kuwait. The overall aim is that an increased understanding of particle characteristics and behavior will help to reduce some of the uncertainties in environmental impact and risk assessment for particle contaminated areas.

The purpose of this book is to present a state of art summary of current knowledge of methods of assessment of radionuclides in the terrestrial and marine environments. It cover the traditional methods of radioactivity measurements such as radiometrics techniques, but also recent developments in the mass spectrometry sector. The book starts with a short preface introducing the subject of the book, summarising content and philosophy of the book, as well as the most important historical achievements. The scientific topics are introduced by description of sampling methods, optimisation of sampling sites and sampling frequency. The recent developments in radiochemical separation methods using chromatography resins for the treatment of actinides, transuranics and other groups of radioelements are also described. No other book is available covering all aspects of environmental radioactivity measurements, although remarkable progress has been made in detection techniques over the last ten years. At present the new methods enable to carry out investigations which were not possible before, either because of lack of sensitivity or because of the fact that they required too large samples.

Reports on the outcome of an IAEA coordinated research project in the area of measurement and characterization of radioactive particles in the environment. This publication summarizes the achievements and findings of the project participants and gives guidance for application of the techniques for evaluation of contaminated areas.