Clearance, Translocation, and Excretion of Beryllium following Acute Inhalation of Beryllium Oxide by Beagle Dogs

Clearance, Translocation, and Excretion of Beryllium followingAcute Inhalation of Beryllium Oxide by Beagle Dogs. FINCH, G.L., MEWHINNEY, J. A., HOOVER, M. D., EIDSON, A. R, HALEY, P.J., AND BICE, D. E. (1990). Fundam Appl. Toxicol. 15, 231–241.Beagle dogs inhaled radiolabeled beryllium oxide (7BeO) particlesthat were calcined at either 500 or 1000'C, resulting in eitherhigh (mean of 50 ng/kg body wt) or low (mean of 17 ug/kg bodywt) initial lung burdens (ILBs) of both preparations of BeO.Levels of beryllium in whole body, tissue, and excreta weremeasured by external -y-ray counting. Dogs were euthanized inpairs at 8, 32, 64, and 180 days after exposure to determineberyllium distribution in tissues. Beryllium oxide calcinedat 1000'C was retained more tenaciously in the lungs (62% ofthe ILB retained at 180 days after exposure) than BeO calcinedat 500°C (14% of the ILB retained at 180 days after exposure).Most of the beryllium that was cleared from the lungs and notexcreted was translocated to the tracheobronchial lymph nodes,skeleton, liver, and blood. More beryllium was translocatedto the skeleton and liver at 180 days after inhalation of BeOprepared at 500*C than at 1000'C. The predominant mode of excretionat early times after exposure was through the feces, with urinaryexcretion assuming predominance at later times. These data areimportant for interpreting the toxic effects of beryllium inthe exposed dogs. Furthermore, because little is known concerningthe retention and clearance of inhaled beryllium in man, theseresults provide information that may be used to understand thedisposition of beryllium in accidentally exposed humans.