the preferred It appears at this point, however, that Universal Kriging may be of contours method since in theory it should yield more accurate estimates are satisfied. than any other approach, at least when underlying assumptions not available Also, as mentioned above, it provides estimates of variability using any other method. SUMMARY the In the first part of this paper, we have attempted an initial synthesis of on 57) (Project 13 Area from available currently data tion 239,240p,, concentra the Nevada Test Site for soil, vegetation, small mammals, and grazing cattle. For the most part, this synthesis has consisted of simple visual comparisons between different trophic levels by plotting all the data on a single graph. The soil and vegetation data are seen to be highly variable within strata, but This large with strata means increasing with increasing proximity to GZ. There is a ons. concentrati tissue mammal small in exists also variability lack of correlation between rodent concentrations and concentrations in the soil where animals live, due perhaps in part to the mobility of rodents. 239,240py concentrations in cattle tissue are also plotted and compared with These comparisons are hampered by the small number of other tropic levels. cattle tissue samples available for statistical analysis. The lowest and highest concentrations were found in muscle and hide and hair, respectively, with lung concentrations falling between these extremes. The single cow grazed in the inner compound (enclosing the GZ area) had concentrations higher than the average for the three cattle grazed in the outer compound for hair and hide, tracheo-bronchial lymph nodes, lung, muscle, and backbone. Equal or lower concentrations were indicated for hide, rumen sediment, red blood cells, femur, and blood serum. Again, we stress the need for more data, particularly for the inner compound, to increase our confidence in these initial comparisons. The concentrations in lungs of the Area 13 cattle are 2 to 3 orders of magnitude greater than for cattle grazed in a control area (Searchlight, Nevada). As for muscle, there are no apparent differences between the outer-compound cattle in Area 13 and the control herd. The muscle data from the one cow grazed in the inner compound suggest a possible elevation of about one order of magnitude above the control herd for that tissue. Observed muscle 239, 24°py concentrations in Area 13 cattle were compared with hypothetical concentrations obtained using Martin and Bloom's plutonium transport and dose estimation model. Their model gave estimates from 2 to 4 times larger than actually observed, suggesting, perhaps, that their model as presently constituted may yield conservative estimates for cattle. Hypothetical human concentrations were also obtained in Area 13 for residence times equal to cattle grazing times before sacrifice. The hypothetical values for human lung and bone were factors of 5 and 8 less than obtained for the single cow in the inner compound. Hypothetical concentrations are also obtained for residence times of 180 days, 720 days, and 55 years for an estimated "maximum permissible concentration" of 3 nCi/g dry of 739,249py in soil. 269