eee ee ee THE HEALTH AND SAFETY LABORATORY SUNSHINE EXPERIMENT It is only natural that the role of this laboratory in the woplcwide monitoring of debris from nuclear detonations should tend to prisnt our SUNSHINE studies towards the fallout data we have accumulkted (1-1), Our studies were designed to achieve maximum utilization of these data. Our choice of exnrriments were influenced by the ultimate objpctives of both SUNSHINE and GABRIEL, and the state of knowledge as reviBwed at ths Rand Conference in early Summer 1953 (5). under four headings: Our studies can bel presented 1. Validity of data from the monitoring network. 2. Fractionation of the strontium isotopes. 3. Some factors involved in the biological uptake of stfrontiun. 4. Atmospheric storage of debris from super bombs. Validity of Data From the Monitoring Network Comparison of Predicted and Measured Concentrations of Radiostrontium in Seil Soils from five selected areas in the United States for strontium 89-90, The predicted Sr89-90 concentration in re analyzed from 0.0067 to 0.26 d/min/gm soil, a factor of LO. Predicted values were calculated from the data of Table 1 wh cumulative fallout for each series of tests since BUSTER-JAN stations in the vicinity of each locality where soils were s theoretical fraction of the total activity due to strontium was obtained from Figures A~1 and A~2 (Appendix A) which hav from data of Hunter and Ballou (6). at network pled. The and strontium? been constructed The radiostrontium content of the soil was estimated by ass density to be 1.5 and all of the activity to be contained in inch of soil. Where radiochemical analyses showed radiostro of soil below Q-1", this activity was added to the measured alue from zare to one inch in order to make the results comparable. Table 2 and Rdeure l summarize the comparison of predicted measured values of Sr°9-90 in soils from five places in the United Sthtes, The measured values in the soils were from 100 to SOS of th® predicted concentration of radiostrontium, In view of the many uncerthinties inherert in both fallout and soil sampling we regard these results as] somewhat fortuitous but, nevertheless, encouraging. A more extensive sampling program seems justified,