172 THE SHORTER-TERM BIOLOGICAL HAZARDS OF A FALLOUT FIELD RELATIONSHIP BETWEEN I'5! ann sr? activity (CORRECTED DATA FOR POOLED SPECIMENS BY WEEKS AND STATIONS) METABOLIC STUDIES WITH STRONTIUM-90 IN THE RHESUS MONKEY | (Preliminary Report) (6,000 ppm 1'>! CORRECTED TO FISSION TIME fo / 14,000 / / ©$,9,10,13,140 By P, W. Durstn, M. W. Parrort, M. TH. Winurams, M. E. Jounston, C. W. Asuna, and J. G. Haminron, with the technical assistance of N. Jevne and 8. A. Cote University of California Radiation Laboratory, Berkeley, California. ABSTRACT 12,000 Adult rhesus monkeys eliminated 56 percent of administered Sr”, compared with 28 percent of Ca®, in the urine during thefirst 10 days after 10,000 / } / 8000- & 10, 13,148 | / 6000F- / 4000F i | x 1 / o8 tal distribution of Sr® was studied. Successive amputation of caudal vertebrae is therefore recommended as the simplest and safest method of acquiring information on long-term skeletal retention of Sr® in valuable animals with long Average half times for skeletal retention of Sr” were calculated for an adult male, 470 days, and for an adult female that had experienced 3 closely spaced pregnancies, 315 days. Half times for skeletal retention of Sr® of 155 and 195 days were calculated for the first 10 months of life of two offspring born to an injected mother. 20007 A r!3t vatue f o ‘ ! 7? AVE. EST. osovacue } 3X,48,14N fh 2 4 6 Neer 8 10 Ae 12°14 16 One infant monkeyretained an average of 18 pereentof Sr® administered daily by mouth for 13 weeks, whereas 6 adolescents retained on the average less than 5 percent of a daily dose dur- ebieebereg fa 18 20 22 24 26 28 30 32 34 36 DPM $r90 Fraure 7.--Relationship between I 131 and Sr 90 activity. ' an injected female taken shortly after the birth of her secondoffspring (402 days postinjection) was 3 to 4 times the Srlevel of a plasma sample taken a few days later. skeleton as a whole in two animals whose skele- life spans. / O 13,14 M 013,14X 7 intravenous administration. The Sr™ concentration in the vertebrae was found to be reasonably representative of the to about 8 percent of the Sr” content of the mother’s skeleton at term. The Sr® concentration in milk samples fram ing the same period of time. A measurable amount of Sr™, 23.5 dpm/g bone ash, was found in the skeleton of an uninjected control animal. Placental transfer from a mother with a fairly well-fixed skeletal burdenof Sr” amounted INTRODUCTION It is generally agreed that Sr™ is potentially the most dangerous of thefission products. It is produced inrelatively high yield in the fission process, and has a long physical half-life Manyof its compounds are quite soluble and are readily absorbed by both plants and animals, Once absorbed by an animal, Sr® is retained for long periods in the skeleton[1]. Dudley [2] has compiled a survey of the literature on Sr® in mammals to mid-1954; this survey is in the formof tables setting forth the animals employed and their age, the dose administered, the length of the sudy, and the effects observed. Numerous investigations have been madeor are under way of the absorption, distribution, and elimination of strontium isotopes under varying conditions in laboratory rodents, [1-7] dogs, [8] and domestic livestock 19, 10}. The most. important animal from the standpoint of human society is necessarily man himself. Data currently being applied to 173