There was also increased environmental concern in the Soviet Union . In the mid-1950s , Soviet scientists began taking regular radiation readings near Leningrad , Moscow , and Odessa and collected data on the prevalence of strontium-90 , which indicated that strontium-90 levels in western Russia approximately matched those in the eastern US . Rising Soviet concern was punctuated in September 1957 by the Kyshtym disaster , which forced the evacuation of 10,000 people after an explosion at a nuclear plant . Around the same time , 219 Soviet scientists signed Pauling 's antinuclear petition . Soviet political elites did not share the concerns of others in the Soviet Union . However ; Kurchatov unsuccessfully called on Khrushchev to halt testing in 1958
Kyshtym disaster
Kyshtym disaster
Partial Nuclear Test Ban Treaty