doses een in iy we must accept a dose of 75 rads Bair and observed s 10 to posure to st be ncidence plutonium 9 lower nal data available veolarloped lung independent of the distribution of dose in time, The only direct measurement of plutonium in the lungs in this study was made on the operative (accumulated over ears of occupational exposure) as inducing specimens of subject No. 2. Table. VI shows results 239 23954. Pu of analyses for The concentration of is. ~alignant tumors and pulmonary scleros in man, Langham? estimated 106 rads to was approximately the same in the tumor and lung 239 the lung as a completely empirical judgment as to a tissue, while the concentration of " at or above which biological consequences Jevel was approximately half. Pu in bone The highest concentration, umav ensue in a small population of limited distrib observed in the lymph node tissue, is consistent tion.” with the experimental findings in dogs exposed to Pud,, by inhalation, as mentioned above. Park and co-workers at Battelle-Northwest It is well report that the plutonium content of the thoracic established that the concentration in lymph nodes lymph nodes of beagles was about the same as that relative to that in lung tissue increases as a of the entire lung tissue about 5 years following 16 a single inhalation exposure. At this time, both a homogeneous distribution of 239 Pu throughout the function of time following exposure. If one assumes lung and lymph nodes and a total lung weight of al organ, 4) percent of the initial alveolar-deposited lung tissue and thoracic lymph nodes contained about 239 Pud,- 1000 grams and respiratory lymph node weight of 3 dog lung. At about lO years following exposure, the lungs con- 20 grams, the total plutonium burden of the lungs 1is amount tained about 12 percent and the thoracic lymph nodes and respiratory lymph nedes is approximately 8 nCi imated about 40 percent of the initial alveolar-deposited roughly equally divided between lung and lymph node. For reference, the total amount of plutonium in the La@ny uo, loodless icant fraction of the original lung burden of our lung of case No. 2 (estimated by tissue assay to ipon human subjects to be present in the thoracic lymph be 3.85 nCi) is approximately 550 times contempo- * mean nodes many years after exposure to plutonium oxide, rary total lung burdens in humans in the United ‘el that However, one must exercise caution, as we do not States exposed to fallout resulting from plutonium dispersed by atmospheric weapons tests. From these data, we might expect a signif- ing (about know whether the translocation rates of plutonium th in oxide are the same for the beagle and man or whether of the chest burden of 239 Pu of subject Noa. 2, ion equiv- the rates observed for beagles with large lung bur- based on extrapolation from analysis of lung and nal lung dens would be realistic for emailer initial alveolar lymph node tissue, are in reasonable agreement (a e, deposits in man. factor of about 2) with estimates based on chest- is velopment net to For Although a single measurement of Estimates 239 by in the chest of subjects exposed 27 to counting. 28 years ago is of little help in obtaining accurate plutonium particle in a section of lymph node re- Figure 10 shows an autoradiograph of a estimates of the current chest burdens, similar moved from subject No. 2. ated to petiodic measurements on several recently exposed plutonium particles in the lymph node tissue re, the individuals have yielded data on temporal changes examined indicate a very nonuniform radiation dose- hen the of plutonium within the chest. distribution from plutonium particulates. Had repeated, be un- periodic measurements been made on the present sub- ature jects, we would have more confidence in our esti- ,out mates of L6) the chest burden. 2. Observations of other Plutonium in Other Tissues. Because we have no reliable calibration system for plutonium conTABLE VI x burden PLUTONIUM-239 CONTENT OF TISSUES REMOVED FROM PATIENT NO. 2 IN May 1971° dents plasms Lung y in- Lymph node - control Hamartoma Rib Moskffect Wet Weight (grams) Tissue evl! oe a Volume of Solution (ml) (dpm per ml) Plut onium-239 d mMpergram) Ci per 70.85 loo 6.01 8.48 3.85 1.25 25 22,55 451.00 205.00 0.77 20.00 25 100 0.23 0.71 7.47 3.55 3.40 1.61 gram) 1 After ashing and dissolution of tissue. yi AN YO 1?