Progress in Studies with Transuranic Elements at the Lovelace Foundation

Abstract

Research directed toward developing an improved understanding of the biomedical consequences of inhaling transuranic elements was initiated at the Lovelace Foundation in 1968, recognizing the need for additional information on these radionuclides as well as the opportunity to obtain data for comparison with those previously collected and being collected on fission product radionuclides. The research is being performed to develop information that will assist in predicting potential effects in man from inhaled transuranic elements, and to provide the data necessary for establishing realistic radiation protection guides. Recognizing the need for quantitative data on the influence of particle size on the toxicity of inhaled alpha emitters, a major, and successful, effort has been directed toward the production of monodisperse aerosols of respirable particles. Studies on the metabolism and toxicity of 23gPu, 241Am, 244Cm and 262Cf have been performed or are under way in mice, Chinese hamsters, Syrian hamsters, rats and Beagle dogs. The effectiveness of bronchopulmonary lavage for removing inhaled radioactivity, including 239Pu, is also being studied. This study, in part, provided the basis for the use of bronchopulmonary lavage to recently treat an individual who accidentally inhaled 23DPu.

ICRP Publication 141: Occupational Intakes of Radionuclides: Part 4

“… (677) Bair (1970) followed the biokinetics of 239 Pu for 300 d after inhalation of 239 Pu nitrate by dogs. Results were also reported by McClellan (1972) for comparison with results on americium and curium. Fifteen dogs inhaled an aerosol of a plutonium HNO 3 solution (0.14N for three dogs killed after 1 month and 0.27N for 12 dogs killed at times between 75 and 303 d).…”

“…In addition, Mewhinney and Muggenburg (1985) studied the influence of age at inhalation on the biokinetics of 241 AmO 2 in beagles. In the studies of americium oxides, lung retention data have usually shown 70–90% clearance with half-times from 10 to 30 d. One exception was the clearance of 241 Am from monkeys in which 32% ILD cleared with a half-time of 0.1 d. The second clearance component was on the order of hundreds of days. (896) McClellan (1972) reported the progress of studies on the biokinetics of transuranic elements in rodents and dogs at the Lovelace Foundation, Albuquerque, NM, USA. The figures presented included data on retention of 241 Am in the lungs, liver, and skeleton over 1000 d after inhalation of the dioxide by dogs, as well as urinary excretion data for 3 w. 241 AmO 2 appeared to leave the lungs much more rapidly than plutonium dioxide or even plutonium nitrate, with a consequent two orders of magnitude difference in urinary excretion rate at early times post inhalation.…”

“…(896) McClellan (1972) reported the progress of studies on the biokinetics of transuranic elements in rodents and dogs at the Lovelace Foundation, Albuquerque, NM, USA. The figures presented included data on retention of 241 Am in the lungs, liver, and skeleton over 1000 d after inhalation of the dioxide by dogs, as well as urinary excretion data for 3 w. 241 AmO 2 appeared to leave the lungs much more rapidly than plutonium dioxide or even plutonium nitrate, with a consequent two orders of magnitude difference in urinary excretion rate at early times post inhalation.…”

Parameters of excitation energy transfer from the4/11/2level of the Er3+ion in (Y1–xErx)3Al5O12crystals

“…The HRTM was applied since particle transport rates in dogs and humans are similar (ICRP 1994a andKreyling et al 1991). The experimental data of Bair and McClanahan (1961), Bair and Willard (1963), Ballou et al (1972), McClellan (1972), Park et al (1972), Bair et al (1980), Stanley et al (1980aStanley et al ( , 1980bStanley et al ( , 1982, Dagle et al (1983), Mewhinney and Diel (1983), Guilmette et al (1984Guilmette et al ( , 1987 were interpreted in this work. (2002) developed models of the respiratory tract and Pu systemic behaviour in rats.…”

Multiplicative effect of inhaled plutonium oxide and benzo (a) pyrene on lung carcinogenesis in rats

“…The radiation doses were expressed as smeared doses (McClellan, 1972), assuming 2g for fresh lung weights and 170 days for half-time clearance, as observed earlier for this strain (Masse, 1980;Pour et al, 1976), malignant tumours being considered the major endpoint of this experiment. Context of observation "incidental'.…”