NAEG PLUTONIUM PROGRAM VEGETATION STUDIES STATUS REPORT, MAY 1975 E. M. Romney Laboratory of Nuclear Medicine UCLA, Los Angeles SCOPE OF PROGRAM The significance of vegetation in any plutonium-contaminated area rests primarily upon its capacity to function as the carrier for plutonium and other transuranics in the food chains leading to grazing animals and man. Two different mechanisms of incorporation are involved in this transport process. First, the contaminant may become superficially entrapped upon vegetation through the processes of resuspension. This is expected to be the most important mechanism in the desert ecosystem, where environmental conditions are favorable to wind-driven forces. Second, the plutonium disseminated in soil may be taken up through plant roots and translocated to the aboveground vegetation. The Nevada Applied Ecology Group (NAEG) vegetation studies are expected to contribute information on how these two mechanisms of incorporation function in the vegetation-carrier transport of plutonium and other transuranics from soil to grazing animals and man. DATA SUMMARY Vegetation samples were collected in conjunction with soil samples from 10 study areas. Laboratory processing and radiochemical analysis of the vegetation samples essentially has been completed for Areas 13 and GMX-5 of the Nevada Test Site (NTS). 31 About 60% of the samples