RADIOACTIVITY ALONG THE 80TH MERIDIAN NUCEAR TESTS WN THE ATMOSPHERE < > 1 s NPG > < aeou ' » << ¥ ‘ r « ' UMITEO STATES UNITED KINGDOM < PPG> oe ' ae SOVIET UNION <> FRANCE ¢ _. 481 > 76°35'N 107! = | ee MOOSONEE ' i | | | | e- WASHINGTON | 38°59'N 2 GROSS BETA ACTIVITY, PC/SCM OF AIR 51°16'N — i 197! ! | | 1072 : | | : | , | | |MIRAFLORES' 5 P00'N | 10° | 107! | 107? Delecbeeede tL 1957 lL del a a a 1958 ed 1 pe ne | 1959 1960 1961 Sd daceetialarerbemndbnas 1962 Fig. 1—Fission-product radioactivity in the ground-level air at some sites in the northern hemisphere. hemispheres, shown in Fig. 3, are based on the naive assumption that the concentration of radioactive material per unit volume found at ground level at a given site is uniform up to the tropopause and is char- acteristic of that latitude. It is recognized that there often exist higher concentrations of activity in the upper troposphere and that, particularly during periods of nuclear testing, there is no uniform distribution within latitude bands. Notwithstanding these and other less obvious objections, this method of presentation does represent rather clearly the behavior of fission debris in the atmosphere. tf §f?

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