In studies on windborne material, Shinn and Anspaugh (1975) have shown that dust flux is sensitive to wind speed, likely due to the avalanching effect from saltation. Saltation is a process whereby large particles moving at the ground surface sandblast the surface, thereby ejecting smaller particles which may be suspended in the air, even though the saltating particles rise no More than one meter above the ground. They compared a highly erodible agricultural soil surface in Plains, Texas, to the low saltation, less erodible surface at Frenchman Flat and found that the airborne dust concentration was proportional to an exponential power of wind speed greater than six. In Nevada conditions, it was closer to a power of two. This suggests that with the same wind speed in both disturbed and relatively undisturbed areas, the airborne material should be decreased by a factor of about 10~. In addition, Phelps and Anspaugh (1975) have developed a timedependent resuspension factor to describe long-term contaminated areas. They showed that the resuspension rate after 20 yrs was much lower than initially. In a practical sense, this infers that the worst of resuspension by wind at all the Pu-comtaminated areas of NTS are long past. They cite values for initial resus- pension factors at 1074 nl, after 17 yrs, the resuspension factor should approximate 107? m “1 a decrease of 107>. Romney et al. (1975) have investigated the surface contamination of vegetation in Pu-contaminated areas of interest to this study. The ratios of the amounts of Pu on vegetation that is primarily on the surface of vegetation, compared to that with soil beneath, tended to be greater on the peripheries of the contaminated areas where the particles of Pu initially deposited by the tests were smaller sizes. Inventory estimates indicated that standing vegetation provides a rather insignificant portion of the total contaminant remaining in the fallout areas. It should be noted in passing that surficial contamination of the shrub species could occur from having soil carried to leaves and stems by wind or some other physical process. 171