The maximum plutonium-239 concentration was only 0.002% of the maximum permissible airborne concentration (MPC-168hr) (ICRP, 1959). for an uncontrolled area The maximum americium-241 concentration was only 0.0057 of the MPC-1l68hr. For a controlled area, the maximum concentrations were only 0.0002% and 0.002% of the MPC-40hr for plutonium-239 and americium-241, respectively. Concentrations in uCi/g Airborne Soil Plutonium-239 and americium—-241 concentrations per gram airborne solids were determined for both "small" and "large" particles. Airborne concentrations in uCi/g are shown in Fig. 3 for plutonium-239. The uCi/g for small particles decreased with increasing height up to 91m. This decrease might be explained by sampling both "more contaminated" locally resuspended particles as well as "less contaminated" soil blowing in from a greater upwind distance. In contrast, for large particles, the maximum uCi/g occurred for a sampling height of 30 to 60 m. This "large"-particle plume concentration profile in yCi/g might be explained by assuming two possible sources of airborne particles were sampled. For one source possibility, contaminated large particles might be resuspending at a distance upwind and the airborne plume he depleted by dry deposition between the resuspension and sampling site. For the second source possibility, many "less contaminated" particles are resuspended near the sampling tower and are sampled. This less contaminated airborne soil being simultaneously sampled with soil from upwind would decrease the uCi/e. Relationship: Plutonium-239 on Large Particles and Americium-241 on Small Particles Airborne concentration profiles in uCi/g are shown in Fig. 4 for ameri- cium-241 collected on both "small" and "large" particles. Only two data points are shown for americium-24]1 transported on large particles. The maximum observed americium-241 concentration on "large" particles was 8 x 1077 uCi/g at the lowest sampling height of 1.9 m. At the highest sampling height of 122 m, the americium-241 concentration on "large" particles had decreased over one order of magnitude to 2 x 1078 yuCi/g. At intermediate sampling heights of 15 to 91 m, americium-241 concentrations were not significantly different from zero due to the radiochemical counting statistic uncertainties. The americium-241 wCi/g on "small" particles was minimum and constant at 1.9- and 15-m sampling heights. For greater heights, a maximum of 4 x 1076 uCi/g was determined at a sampling height of 91m. A possible explanation for this americium-241 on "small" particles is that resus- pension occurs at a distance upwind and the airborne plume is depleted by particle dry deposition between the resuspension and sampling site. Also, many less-contaminated americium-241 small particles might be resuspended near the sampling tower and be collected in the sample. These less contaminated "small" particles would be simultaneously sampled 713