A computer-controlled sampling system is undergoing final develop- ment at Livermore. This system will monitor and record a variety of meteorological parameters and can turn samplers on and off according to preset constraints in terms of meteorological conditions. This system will be used for long-term studies designed to verify predictive models. Field operation of this system should begin early in FY 1976. Additional data analysis is being performed on measurements made at the GMX site. This includes our own measurements for which radionuclide analyses only recently became available and data collected by Reynolds Electrical & Engineering Company, Inc. (REECo), at this site before our own measurement program started. Analysis of data collected at other NTS locations is also under way. Data will be reported for the concentration of resuspended Mass and 2395 and for their distributions with particle size. The resuspension element has been actively supporting development of a more sensitive in sttu detector for 23 Pu and/or 241am, In the past, we have reported a general calibration method (Anspaugh et al., 1972) for the FIDLER and have also reported on the use of a large Ge(Li) in situ detector which is an order of magnitude more sensitive than the FIDLER. A prototype of a more desirable Ge(Li) detector configuration has been fabricated and is undergoing laboratory testing. If these are successful, field trials in the GMX location will be conducted in early FY 1976. FUTURE STUDIES A major experimental program at the GMX site is scheduled to begin in The airborne sampling system will be used to measure mass concentrations in dust devils in order to estimate the mass flux per dust devil. The frequency of occurrence of dust devils will also be recorded by ground observers. At the same time, surface air sampling for 2395, determination will be conducted with emphasis on studying resuspension during a range of meteorological conditions 96 sob ni milenawantllieiatptineme mame ss July, 1975.