“ l T T T o RUMINANTS e PIGS 30 = — (SIZE OF CIRCLE INDICATES S COUNTING ERROR) ° aq co) Z O s P= oe . 20 ao — 8 Qo a wm 1 + ° 10 -- oO ° oO ou 1953 ° | 1954 Oo 1955 — Oo 9° ° el 8 oO g | | 1956 1957 Fig. 1—Strontium-90 in animal bone. ef 90 | 7 T T 7 gO -— uw | J — + _ — + 70 a o 60 + + 3 = 50 = SC 40k oO + LLL * ft ++ 20 | CALCULATED AVERAGE — + +4+++ a + ASSUMING 24 MEGATON ++ AND TROPOPAUSE TO —1 40,000 FT. AT REPORTED EFFICIENCY OF 25% — p + + NN averace “a * — + + 10 fr ok 30 . | 60 + t + +4 NORTH 30 ¢ a O 30 LATITUDE Fig. 2—-Stratospheric Sr®’ content. 298 L SOUTH 60 L 30