Skeletal /sup 212/Pb retention following /sup 224/Ra injection: extrapolation of animal data to adult humans

Journal Article · Thu Mar 31 23:00:00 EST 1988 · Health Phys.; (United States)

DOI:https://doi.org/10.1097/00004032-198804000-00001· OSTI ID:6997545

Schlenker, R A

Two methods of interspecies extrapolation, one based on a correlation of skeletal /sup 212/Pb//sup 224/Ra with body weight, the other based on the mechanistic relationship between skeletal /sup 212/Pb//sup 224/Ra and reciprocal bone surface-to-volume ratio, lead to the conclusion that the retention of /sup 212/Pb in the adult human skeleton is approximately complete a few days after injection. The correlation-based method gives most probable values for /sup 212/Pb//sup 224/Ra of 1.0 and 1.1 at 2 d and 7 d after injection, compared with values of 1.05 and 1.27 expected at these same times if the retention of /sup 212/Pb were complete from the time of injection and if no /sup 212/Pb were in the injection solution. The range of values corresponding to one geometric standard error on either side of the most probable value is 0.87 to 1.21 at 2 d post-injection. With the method based on the reciprocal bone surface-to-volume ratio, the best estimate of /sup 212/Pb//sup 224/Ra at 2 d after injection is 0.88, equal to the value observed in young adult beagles. An alternative interpretation of the results of this latter method leads to the conclusion that retention is complete, with /sup 212/Pb//sup 224/Ra equal to 1.0 for a /sup 212/Pb-free injection solution and 1.1 for a solution containing /sup 212/Pb in secular equilibrium with /sup 224/Ra. This work, which uses /sup 224/Ra daughter product retention data from mice, rats and dogs following 224Ra injection, provides a scientific foundation for retention assumptions made in the calculation of mean skeletal dose for adult humans. There now appear to be few uncertainties in these latter dose values, stemming from inaccurate retention assumptions; but substantial uncertainties remain in the mean skeletal dose values for juveniles and in the endosteal tissue doses regardless of age.

• Research Organization: Argonne National Lab., IL (USA)
• OSTI ID: 6997545
• Journal Information: Health Phys.; (United States), Journal Name: Health Phys.; (United States) Vol. 54:4; ISSN HLTPA
• Country of Publication: United States
• Language: English

Related Subjects

560162* -- Radionuclide Effects
Kinetics
& Toxicology-- Animals
Plants
Microorganisms
& Cells
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AGE DEPENDENCE
ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
ANIMALS
BEAGLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MODELS
BIOLOGICAL VARIABILITY
BODY
DAYS LIVING RADIOISOTOPES
DOGS
EVEN-EVEN NUCLEI
EXTRAPOLATION
GENETIC VARIABILITY
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
ISOTOPE RATIO
ISOTOPES
LEAD 212
LEAD ISOTOPES
MAMMALS
MICE
NUCLEI
NUMERICAL SOLUTION
ORGANS
RADIOISOTOPES
RADIONUCLIDE KINETICS
RADIUM 224
RADIUM ISOTOPES
RATS
RETENTION
RODENTS
SKELETON
VERTEBRATES