that have not yet been experienced during previous measurement periods. Simultaneous measurements of mass loading will be made with the use of fast-response instrumentation. It is also planned to participate in proposed trials of clean-up procedures for contaminated soils. Such studies will provide a valuable opportunity to document the influence of artificial disturbances on the resuspension of plutonium. Such data are needed for input to cost-benefit analyses of plutonium cleanup, particularly for aged sources. Additional experimental work will also continue in order to further define and verify the tentative (but critically important) parameterization of the mass flux of suspended soil as a power function of friction velocity with power depending upon the Soil Erodibility Index. More effort will be devoted to developing and publishing a useful, general model of the resuspension process. Part of this effort will be to adapt a model of atmospheric transport and diffusion so that it will be particularly useful in predicting the concentration of resuspended contaminants downwind from a localized source of any geometrical configuration. A critical lack in the development of a general model is an adequate description of the weathering process which involves the attachment of deposited contaminant to host soil and its downward migration through the soil. Future efforts will be devoted to modeling this process from a fundamental basis, and additional Measurement programs at appropriate sites will also be designed to examine this process. ACKNOWLEDGMENTS The resuspension work at the Nevada Test Site is a joint effort with Lawrence Livermore Laboratory funding provided by the Division of Biomedical and Environmental Research, U.S. Energy Research and Development Administration. The Nevada Operations Office provides 97