- oe Ae en ae ee allele bes ares ett bree aa en er It was then alpha countea, (79) secticns of Illinois in which the Ra“? skeletal levels in the population are 10 times those of their neighbors. pae2o was determined by the radon emanation method of Lucas, (22) The differences are caused by The ash content was determined from the calcium, expressed as calcium variations in the pae®® concentrations in the drinking water, (2) RaD is another such nuclide. phosphate, which, because of a series of compensating factors, is equivalent As shown in Fig. 1 (Slide 1}, RaD is to the ash. (9) \ a pav“o decay product, but one does not expect it to follow the parent because of their different chemistries and the long half life of RaD. III. The most important difference is that RaD is derived from the rare gas : 2 : 4 Interpretation of these measurements to obtain meaningful * conclisions involved certain problems. intermediate, n° 2 which is easily translocated from the parent Ra??o Only in the lust fev years has naturally occurring RaD been studied. representative of the whole. Considering the amount of information Thus, 7 compared to the subsequent measured values of piack’?) of iii (8) and ol this Hursh (10) using small sections cf bone. On the other hand, was from a single individual. (Slide 2). Data from 8 sets are shown in Table I Within a facvor of 2 or so (with a few excepvions) any given pone appears to be representetive. Experimental Technique of Rab, ReF and pae26 in human specimens. | These consisted of surgical | and autopsy specimens of soft tissue and bone obtained from medical sources. . that a given bone represents the total skeleton {as defined by a few samples}, and for lack of a better hypothesis, it has tvzen assumed tnat RaD. Next, the nitrates were The results in Table 3 (Slide 4) show about SO% of the activity to be in the skeleton, a resuit also in agreement with that calculated destroyed by repeated fumings with hydrochlorie acid, and finally, after from the wietabolic parameters of stable lea q, was pluted onto a silver disk at g0° ¢. 412,15) Sinee the skeleton constitutes about 10 to 15% of the total body waight, and contains more -2- <TR neg Because of the fairly high probability The second problem considered was the whole-body distribution of The analyses were performed by first wet ashing 10 with a few notable exceptions. the distribution of RaD is wniform within the sxeleton, The RaD was determined by analysis of its decay product Rar (po?) the samples with nitric and perchloric acids, Table 2(Slide 3) shows the Rae" concentrations to be relatively constant within’a given individual, again vor this study particular effort was devoted to the determination adjusting to pH 0.3, the Po" Thi. was dane by the use of sets of bane sections, tibia, sk 41, mandible and either rib or joint bone, in which each sat measuring whole body asn, found the RaD content to be only (Fig. 1}(Slide 1). it was necessary to determine how well they represented tne entire Skeleton ard body. abour 1/2 tnat of the Rae? | Ii. Only small samples were available and even if larger ones pad been available, processing would have been difficult. available at that time, this conclusion was quite reasonable wher laboratory (9) The first, was that of the sampling procedure, that is, to determine if a particular semple is Dudley, ‘° estimated the body content of this nuclide tc be about 10 times that of Ra@"°, Results and Discussion x - i