a ie ser= YNCLASSIAIED THE HEALTH AND SAFETY LABORATORY SUNSHINE EXPERDMENTS It is only natural that the role of this laboratory in the worldbide monitoring of debris from mclear detcnations should tend to oriient our SUNSETNE studies towards the fallout deta we have accumilate! (1-1). Our studies were designed to achieve mximem utilization of these data. Our choice of expariments were influenced by the ultimate objectives of beth SUNSHINE and GABRIEL, and the state of knowledge as revieweal at the Rand Conference in early Sumer 1953 (5). Or studies can be under four headings: : prinsented 1. Validity of data from the monitoring network. 2. Fractionation of the strontium isotopes. 3. Some factors involved in the biological uptake of strominn L. Atmospheric storage of debris from super bombs. Validity of Data From the MonitoringNetwork Comparison of Predicted am Measured Concentrations of Radiostrontium in Soil Sils from five selected areas in the United States we for strontium 99-90. ‘the predicted 8r59-9 concentration in so from 0.0067 to 0.26 d/min/gm soil, a factor of oO. Predicted values were calculated from the data of Table 1 which cumlative fallout for each series of tests since DISTER-JANGE Stations in the vicinity of each locality where soils were sanp analyzed varied records [at network theoretical fraction of the total activity due to strontium? was obtained from Figures A-1 and A-2 (Appendix A} which have been constructec from data of Hunter and Ballou (6). The radiostrontium content of the soi) was estimated by as density to be 1.5 amd all of the ectivity to be contained in inch of soil. Where radiochemical analyses showed radiocstrontivm of soil below O-l1", this activity was added to the measured valve to one inch in order to make the results comparable, the soil upper in layers froa zero Table 2 and measured Pigure 4 summarise the comparison of predicted and Values of Sr°9-90 in soils from five places in the United Stated. concentration of radiostrontium. In view of the many uwiertainties inherent in both fallout and soi] sampling we regard these results as s fortuitous but, nevertheless, encouraging. 4A more extensive s Sseng justified. -VU- — 105 1043 — 00131986 O14