The first break in the pattern of nuclear testing came in 1958, when the
nuclear powers agreed to a 1-year test moratorium. The world’s political
and emotional climates were changing. For more than 5 years, the United
States, which had announced its Atoms-for-Peace Program in December
1953, had been endeavoring to place emphasis on the use of atomic energy
for constructive purposes. The Atomic Energy Act of 1954, liberalizing
provisions of the 1946 law, contemplated for the first time private
development of nuclear power resources and established authority for
international activities. In 1957 the Atomic Energy Commission initiated
its Plowshare Program for the development of peaceful uses of nuclear
explosives.[11]
[Illustration: _Distribution of fallout radioisotopes on Rongelap Atoll
as determined by a survey in 1961. Note the interrelationships of man,
plants, animals and the environment._]
Amid such changes there was arising, too, a wider apprehension
concerning the possible effects of fallout. The United Nations in 1955
appointed a committee of scientific representatives of 15 nations to
study the effects of radiation on man. In the United States the National
Academy of Sciences published in 1956 the first of its summary reports
on the biological effects of atomic radiation.
Nuclear testing was not ended by the 1958 agreement, yet the
moratorium—which was renewed annually until 1961, when the U.S.S.R.
broke the agreement by initiating a new test series—was significant as
an experiment in nuclear restraint. After the United States conducted a
final test series near Christmas Island in 1962, new discussions of ways
to halt successive rounds of nuclear test programs were held. Finally,
in 1963, the Nuclear Test Ban Treaty was signed by most of the nations
of the world. The treaty was, among other things, a declaration against
worldwide fallout.