Dose responses from inhaled monodisperse aerosols of {sup 244}Cm{sub 2}O{sub 3} in the lung, liver and skeleton of F344 rats and comparison with {sup 239}PuO{sub 2}
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM (United States); and others
The purpose of this study was to obtain information on the {alpha}-particle dose-response relationship of {sup 244}Cm in rats. Rats were exposed briefly by inhalation to graded levels of monodispersive aerosols of {sup 244}Cm{sub 2}O{sub 3} heat-treated at 1150{degrees}C. The initial lung burden (ILB) of each animal was determined by the use of the {gamma}-ray-emitting radionuclide {sup 243}Cm in the aerosols. Seven groups of 84-day-old F344/Crl rats (a total of 637 males and 645 females) were exposed once to {sup 244}Cm{sub 2}O{sub 3} or sham-exposed to filtered ambient air. Mean ILBs of all rats per group ranged from 0.51 {+-} 0.17 ({+-}SD) to 240 {+-} 82 kBq kg{sup -1} body weight. Mean life-time {alpha}-particle doses to the lungs per group ranged from 0.20 {+-} 0.069 ({+-}SD) to 36 {+-} 6.5 Gy. After death, each rat was radiographed and necropsied. Dose-related increases occurred in incidences of benign and malignant lung neoplasms, except for the groups of rats with higher mean ILBs that were examined histologically (98 {+-} 18 and 240 {+-} 77 kBq kg{sup -1} body weight) in which survival was markedly decreased. Also, average {alpha}-particle doses of 0.0014 {+-} 1.1 Gy were also absorbed by the liver and skeleton, respectively, in the rats in the different exposure groups. Primary liver neoplasms occurred in several rats. However, the incidence of these lesions was not related to dose. Increased incidences of bone neoplasms occurred only in rats receiving higher doses to the skeleton. Inhaled {sup 244}Cm{sub 2}O{sub 3} appeared to be about 50% less effective as a lung carcinogen in rats compared to {sup 239}PuO{sub 2} similar doses. 58 refs., 10 figs., 10 tabs.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-76EV01013
- OSTI ID:
- 535359
- Journal Information:
- Radiation Research, Vol. 147, Issue 5; Other Information: PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
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