After reviewing Project GABRIEL in 1953 , it was given first priority status . The secret project would define " practical limits " for using atomic weapons . A task team was assembled and the codename used was " Project HORN . " In 1954 , AEC argued that fallout was harmless because there was not enough evidence to prove that fallout would harm humans , animals , or crops . The AEC campaign persuaded the public that the worldwide fallout was harmless . This claim was later disputed when scientists announced publicly that there was no safe level of radiation . This was confirmed in a confidential report by a geneticist for the AEC . By 1954 and the Castle Bravo incident , it was obvious that radioactive fallout was dangerous to humans . The United States Atomic Energy Commission Division of Biology and Medicine dealt with efforts directed towards experimental and field studies and the correlation of data dealing with Project GABRIEL . The RAND Corporation , Laboratories at Columbia University , AEC 's New York office , the University of Chicago , an exclusive group of scientists , UCLA , and the United States Air Force were all involved in collection and testing of samples from around the world for radioactive fallout
Castle Bravo
Castle Bravo
Project GABRIEL