B.R. Johnson, D. Berkovits, E. Boaretto, Z. Gelbart, S. Ghelberg, M. Paul, V. Sossi, Hebrew University, Israel

O. Meirav, E. Venczel, TRIUMF, Vancouver, Canada

J. Prior, University of British Columbia, Canada

Nuclear Instruments and Methods 92 (1994) 483-488

We are investigating long- and short-term processes that involve the resorption of the bone calcium in the human body, using accelerator mass spectrometry of 41Ca (T1/2 = 104000 years). The evolution of an injected dose of 41Ca has been followed over 900 days by measurements in urine and serum. The 41Ca/Ca isotopic ratio rapidly decreased after injection and after about 100 days, reached a quasi-steady state of 1.5 x 10^-11. Variations in this level would signal a change in rates of calcium resorption from the bone.