3 which have and may continue to cause their distribution, is the logica! starting point for study. 2. OBJECTIVES OF THE STUDY The objectives of this study were divided into three parts, as follows: 1. A review of relevant literature related to the oriqin, and the physical and chemical characteristics of fallout debris and transuranic radionuclides produced at Bikini Atoll. 2. Measurements of the concentrations of selected alpha and gamma emitting radionuclides in sediment samples collected in 1972. 3. Interpretation of the measurements in terms of physical, hydrological and chemical processes. Special attention is given to interpretations which may be important to present redistribution processes and may relate the observed data to data reported by other investigators. Because of its significance and the difficulty of obtaining data for alpha emitting radionuclides, the prime emphasis of this thesis is placed on the plutonium and americium-241 data. 3. PROBLEMS, PROCESSES AND LITERATURE: AN OVERVIEW To interpret the distribution of pollutants in the environment requires consideration of many variables, including the physical-chemical properties of both the pollutant and the components of the environment under investigation. Since the scope of this study thus becomes very broad, careful consideration of previous information concerning the pollutants fate and behavior greatly facilitates subsequent study. The initial distribution of radioactive debris from each test would be expected to be strongly influenced by the following factors: (1) the size and location of each detonation; (2) local hydrological conditions; (3) the physical-chemical properties of the radionuclides; (4)