239pu and 241Am CONTAMINATION OF SMALL VERTEBRATES IN NAEG STUDY AREAS OF NTS AND TIR Kenneth S. Moor, Shirl R. Naegle, and W. Glen Bradley Department of Biological Sciences University of Nevada, Las Vegas ABSTRACT Nevada Applied plutonium (Pu) 1972, and were 1973. Much of Ecology Group ecological studies of small vertebrates in three contaminated study areas of Nevada Test Site began in Spring, expanded to include four areas of Tonopah Test Range in Fall, the basic inventory and ecological data on small vertebrates have been previously reported. This progress report consists primarily of presentation and analysis of radioanalytical data on rodents and lizards from Area 11-C, Nevada Test Site. In addition, methodology and preliminary results of initial hematologic studies are presented. Dtpodomys microps is a dominant rodent species in all study areas. Concentrations of 239Pu and 2*1Am in pelt, GI tract, and carcass of 74 resident D. miecrops from five study areas were determined. The only consistent trend evident was that carcass burdens were lower than pelt or GI tract burdens by a ' factor of 102. Mean ratios of Pu/Am in tissue aliquots were variable, and many were significantly different than ratios in soil or vegetation samples. Rodents which were resident near GZ, Area 11-C, in high activity strata (>25,000 CPM **14m) had higher Pu concentrations in the three tissue components examined than rodents which resided in lower activity strata (<25,000 CPM Am) at greater distances from GZ. Whereas Pu concentrations in small vertebrates were variable and did not differ significantly between trophic categories, Pu/Am ratios in carcasses of insectivore-omnivores were significantly higher (P<.01) than mean ratios reported in soil and vegetation samples from Area 11-C. Studies on food sources and microhabitats frequented by rodents are needed before Pu and Am uptake can be properly evaluated. 193