Twenty-seven beagles were individually exposed by inhalation to <tex-math>${}^{144}{\rm CeCl}{}_{3}$</tex-math> in a CsCl vector aerosol (Activity Median Aerodynamic Diameter ∼1.5-2.2 μm) for 4-10 min yielding initial body burdens of <tex-math>$1.6-4.4\ \mu {\rm Ci}\ {}^{144}{\rm Ce}/{\rm kg}$</tex-math> body weight. Of the <tex-math>${}^{144}{\rm Ce}$</tex-math> activity inhaled, an average of 71% (range = 51% to 94%) was deposited in the total body and an average of 35% (range = 13% to 55%) was associated with long-term retention. The behavior of the inhaled <tex-math>${}^{144}{\rm Ce}$</tex-math> was followed by whole-body counting, excreta collections, and tissue analyses following serial sacrifice of groups of three dogs from 2 to 512 days after exposure. After an early clearance from the upper respiratory tract, most of the remaining body burden was retained with an effective half-life similar to the physical half-life of <tex-math>${}^{144}{\rm Ce}$</tex-math> 284 days. As <tex-math>${}^{144}{\rm Ce}$</tex-math> was absorbed from the lung, it was deposited primarily in liver and skeleton; maximum tissue burdens were observed at 8 days after exposure. An analog model describing the metabolic behavior of <tex-math>${}^{144}{\rm Ce}$</tex-math> inhaled in this form by beagles was used to calculate tissue doses. A long-term retained burden of 1.0 μCi <tex-math>${}^{144}{\rm Ce}/{\rm kg}$</tex-math> body weight in a beagle resulted in potential infinite doses to liver, lung, and skeleton of 220, 90, and 67 rads, respectively. Direct extrapolation of these results to humans indicates that the limiting maximum permissible annual intake based on 15 rem/year and a pulmonary deposition of 20% is that for liver, 13 μCi. This results in an average occupational air concentration that is one-half the maximum permissible concentration in air currently recommended for <tex-math>${}^{144}{\rm Ce}$</tex-math> inhaled in a soluble form.

Skip Nav Destination

Close

Article navigation

1 October 1974

Research Article|
October 01 1974

# Toxicity of <tex-math>${}^{144}{\rm Ce}$</tex-math> Inhaled as <tex-math>${}^{144}{\rm CeCl}{}_{3}$</tex-math> by the Beagle: Metabolism and Dosimetry

*Radiat Res*(1974) 60 (1): 133–154.

Citation

B. B. Boecker, R. G. Cuddihy; Toxicity of <tex-math>${}^{144}{\rm Ce}$</tex-math> Inhaled as <tex-math>${}^{144}{\rm CeCl}{}_{3}$</tex-math> by the Beagle: Metabolism and Dosimetry. * Radiat Res* 1 October 1974; 60 (1): 133–154. doi: https://doi.org/10.2307/3574012

Download citation file:

Close

## Sign in

Don't already have an account? Register

### Client Account

You could not be signed in. Please check your email address / username and password and try again.

### Sign in via your Institution

Sign in via your Institution### Citing articles via

Commonalities Between COVID-19 and Radiation Injury

Carmen I. Rios, David R. Cassatt, Brynn A. Hollingsworth, Merriline M. Satyamitra, Yeabsera S. Tadesse, Lanyn P. Taliaferro, Thomas A. Winters, Andrea L. DiCarlo

Low-Dose Radiation Therapy (LDRT) for COVID-19: Benefits or Risks?

Pataje G. Prasanna, Gayle E. Woloschak, Andrea L. DiCarlo, Jeffrey C. Buchsbaum, Dörthe Schaue, Arnab Chakravarti, Francis A. Cucinotta, Silvia C. Formenti, Chandan Guha, Dale J. Hu, Mohammad K. Khan, David G. Kirsch, Sunil Krishnan, Wolfgang W. Leitner, Brian Marples, William McBride, Minesh P. Mehta, Shahin Rafii, Elad Sharon, Julie M. Sullivan, Ralph R. Weichselbaum, Mansoor M. Ahmed, Bhadrasain Vikram, C. Norman Coleman, Kathryn D. Held

Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light

Manuela Buonanno, Brian Ponnaiya, David Welch, Milda Stanislauskas, Gerhard Randers-Pehrson, Lubomir Smilenov, Franklin D. Lowy, David M. Owens, David J. Brenner