"re adCE etal ONE Uh Ub ~ wacbhaarel au ey “asd 5 maton 40 dirtenerLiebegtfete antlet id nataste +h SE eg injection. Lymphoma of the hepatic lymph nodes of a pig receh ing plureriis- nitrate subcutaneously ts reported by Mia Cianahan ct al (U3). OF special nts in the study of Yule. Gibb & Morraw(90) i+ the fuct that lume ‘esioees so to reflect total pulmenary rediation dose while fymph node damage was on. ¢sensitive tr dose rate. Few * metabolic” studies of tissue distribution follow through the Ixag-te: toxicity to the extent seen in the work of Rosenthal & Lindenbaum (94) In ine werk plutonium received by intravenous Hjection in monomeric form eos clearly mare carcinogenic to bone (CF #1 female mice: than simuar doses received in polymeric form. The mice receiving the monomeric borin AEs Les earlicr with ostecsarcoma and developed about twice the inudence coin numbers of mice with tumors and in numbers of tumors per mouse, Por hee concentratian of monomence plutonium upon endosteas surfaces of meno: and veiicbral trabeculae mus have played an important role in this poet ea so but it is dificult to arrive at a factor of 2 by this explanation alone. Tae re meric piutonium deposits to a greater extent than monomeric in fiver ard eo elements of the reticulo-endothelial system and incidence of hepatomas was © with the polymeric form compared to 2-3°4 with the monomeric plutonium. Whether or not this difference contributes also cannot be decided. Also the phenomenon may not occur to the same degree at very low concentrations of the nuclide. The above maycontrast with the findings of Della Rosa & Stannard (95) with oe vate le ' 21Cbo where large differences in tissue distribution did not influence acure eel poten Hest ttestagnt Aas TB ee toxicity. However the end points are quite different, eiz: LDsg versus carcinogenicity. 239 All of the work quotes. above refers to *""Pu. Toxicity oF 22"Pu has heen reported as greater than ?“5Pu on an activity basis (96) but the data d> ner extend to relative carcinogenicity. Irradiated nuclear fue’s always contain some americium-24! along with plutonium. For this reason comparative carcinogenicity of **’Ara to 77°PG is of interest. Taylor & Bensted (97) have recently negated earlier findinz showing equal toxicity of these two nuclides in a long-term study in rats. in ther experiments ?7*!Am appears to be much less effective than 73°Pu in protucing bots Cas 1 the my ‘ j wii Bae Mh pate ake ‘yes Sot banks bone tumors: 21°4 and 47°% incidence in animals receiving 2.5 uCi kg or 7 uCi kg of 74'Am respectively, compared to 80°% incidencein animals receiv inz 2.9 uCi kg of ?°°Pu. The difference is witributed by ihe authors to davereiccs eee gee ar in the chemical handling of the trivalent americium compared to tac preder .nantly tetravaient plutonium, eg. differences in binding to plasma proter-, clearance rate, etc A few soft tissue lesions, including loukentia, were seen is this study but not tn sucficient numberto aiow a comparison oF effect eres. Even though ne cancer cases or ather serious cesions feseemt oc) ters 7 injury} have appeured in man, the popuiauon of fraloaia: WOK Ses rs Gand, constant surveillance (741 A United Stites Trars-Parvomun Regge bes Ree, organized under the sporsership of AEC bythe Manford Fovircnmental Hea th Foundation and all possible efforts are being made to study this greup for cor.- RTTeg EeCHESerage” rvieSeer ut ella oathsith ges Ta as eengal PSSICIScAIITET, : restenaiy By . EME Tb peep doy ethene Sgt hiss: 2 ae ek « a $ + fone es WTSISper et are veceny pera roe ye Phavepes ree hy paeifense ep ater al he oe ' ’ PARI Hon fete Dn Sd vor ee 7 oa BP gee, _¢ . ay hee nye ty tae _ abe ’ pote oe a ’ gy RE a Ee na geen a cat MR a A - Wine dy, OSESETE diag reerfethen Wgy ay os pita Setncdeaie Ns hla