Research Progress Report 1 The objective of my research is to determine the plutonium distribucion in human teeth samples and compare it with that found in animal samples. Figure 1 and Yable 1 are pictures and captions on alpha and beta autora- diographs of teeth samples from beagles injected with different radionuclides. Only if the distribution in human teeth samples correspond tothat in anima] samples can one use Leeth to bone catios from animal experiments to obtain bone burden from human Leeth activity cuncentration for human beings. The experimental procedure involves fission track autoradiography on thin sections of embedded teeth. Fission track autoradiography has to be used instead of alpha autoradiography because the level of activity concencentration in the teeth are it will take several months of such low quantities, around 200 £Gi/gm, that to obtain an alpha autoradiograph. In view of the fact that Marshall Islands soil samples have shown trace quantities of uranium and Chorium, itt was deem necessary that Pu/i§ ratios be obtained allay doubt on the origin of the fission tracks in the autoradiographs. to Attempts will be made to obtain Pu/Th and Pu/Sr as well as Pu/gamma emitting radionuclides Briefly, on each entire LT have done a tooth. trial run for fission track autoradiography. Details of the procedure on the two teeth samples used are described in Table 2. Table 3 lists the modifications to be tried on the next batch of samples. Figure 2 shows the flow chart for obtaining the different ratios on the whole teeth samples that will be subjected to the radiochemistry procedures. At the moment, FT have done qualitative identification of gamma emitting radionuclides and tave found for possible radionuclides the daughter products of Th-232 and U-238. That is all for now. Pleven | Placence ‘I. cc. Dr. Landolt ) . Dr. Ziemer Dr. Dr. Vetter Naum ) “Dr. Naidu T. Greenhouse Dr. Pratt co-chairmen, Cia. Cua Purduc Purdue BNL adviser Dose Reassessment project, Marshall Islands Radiological program Program Director, Marshall Islands Radiological Program Marshall Islands Medical Team Director