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Ce144 is an important radioisotope of cerium because it is formed as the result of uranium fission. Consequently, it is a predominant fission product in a reactor inventory after a period of sustained reactor operation as well as a major isotope released following nuclear accidents. The energy released during a nuclear explosion is sufficient to bond 144Ce to several anionic species depending upon the immediate environment. Among those anions are included citrates, oxides, halides and inorganic debris such as clay particles from earth or structural materials. Because the major route of entry of contaminated materials is by inhalation, it is necessary to collect quantitative information on the solubility of an inhaled radionuclide in body fluids and its metabolic behavior is necessary to correctly interpret bioassay data and to properly assess radiotoxicological hazards. Experiments were performed in which mice were exposed to aerosols generated from solutions containing 144Ce as cerium chloride, cerium citrate or cerium entrapped in fused-clay. The aerosols had particle size distributions that averaged 1.34 m activity median aerodynamic diameter from the cerium chloride solution, 1.72 m suspension of cerium in fused-clay and 2.36 m from the cerium citrate solution. Some animals were sacrificed immediately following exposure for the purpose of studying whole body deposition as a function of particle size and chemical composition. The remaining animals were retained for whole-body counting until sacrifice at either 1, 2, 4, 8, 16, 32, 64 or 128 days after exposure. All animals necrotomized and tissue samples were analyzed for 144Ce content. In addition, urine and feces were collected separately throughout the period of investigation to determine the amount of 144Ce being eliminated by each route.

Project Sponsors

The Associated Western Universities and Lovelace Foundation for Medical Education and Research for sponsorship; Dr. Roger O. McClellan for providing the opportunity to perform the research; Dr. Marvin L. Riedesel, departmental advisor and committee chairman who devoted considerable time and effort to the preparation of the thesis and a most special thanks to Dr. and Mrs. Robert Go Thomas who, in addition to devoting a vast amount of time to all phases of this research, consistently offered their advice and experience. Without their support this project could not have been completed.



Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Marvin LeRoy Riedesel

Second Committee Member

Martin William Fleck

Third Committee Member

Gordon Verle Johnson

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