The years between the establishment of the Pacific Proving Ground and
the signing of the 1958 nuclear test moratorium were years in which the
quest for environmental information could not keep pace with the rapid
growth of nuclear capability. But the growth in the field of weapons
served to underline the need for information and produced certain
landmark developments in environmental research.
The detonation of the first thermonuclear device projected the problem
of environmental contamination to the stratosphere and, literally, to
every part of the earth. This explosion, Test Mike, largest on earth to
that time, was set off on Elujelab Island, on the north rim of Eniwetok
Atoll, on November 1, 1952. In the reef where Elujelab had been, the
blast left a crater almost a mile in diameter and 200 feet deep. The
towering nuclear cloud rose in 15 minutes to a height of 130,000 feet.
Test Mike marked a point of change. Before, fallout from nuclear
detonation had been principally local, touching the waters and reefs of
an atoll or a desert landscape. After Test Mike, the implications of
fallout obviously were global.
A mishap in connection with a 1954 thermonuclear test at Bikini
contributed in two important ways to the enlargement of environmental
investigations. Fallout from the test, swept off its predicted pattern
by unexpected winds at high altitudes, deposited debris on Rongelap, an
inhabited atoll east of Bikini, and on fishermen aboard a Japanese
vessel operating in the Bikini-Rongelap area. The accident, unfortunate
in its consequences at Rongelap and in Japan, had other results of even
wider impact. From it came the first international approaches to the
problems of ocean contamination and, later, long-term bioenvironmental
studies at Rongelap itself.
[Illustration: _School of surgeonfish off Arji Island, Bikini Atoll,
August 1964. Note coral growth on lagoon bottom._]
Wide-ranging studies of ocean-borne radioactivity were initiated by the
Japanese. The experience of the fishermen produced in Japan a fear of
contamination of fisheries resources as a result of the United States
tests. One result was the organization, in the summer of 1954, of a
government-sponsored ocean survey expedition that cruised from Japan
into and through the Bikini-Eniwetok area to determine what amounts of
radioactivity were being carried, by water and by aquatic organisms,
toward the shores of Japan.
The expedition made significant observations of the role of plankton[10]
in the biological utilization of ocean fallout. A United States
scientific team, following up the Japanese effort, made a similar but
far more extensive cruise through the Western Pacific early in 1955 and
went on to Japan to discuss its findings with the Japanese. During and
after the test series in the Pacific in 1956 and 1958, United States
surveys of the ocean were made routinely. Exchanges of information
between scientists of Japan and the United States continued.
The Rongelap case produced results of another kind. The Rongelap people
were found to have suffered exposure requiring medical attention and
continued observation. Evacuated from their atoll because it was not
safe, members of the community were given care at other atolls until
they could be repatriated in 1957, and received continued medical
supervision thereafter.
The bioenvironmental condition of Rongelap was unique. The fallout had
made the atoll the only place in the world contaminated on a single
occasion by relatively heavy deposition of radioactive debris without
also being disturbed by a nuclear explosion. In 1957-1958, after the
Rongelapese had been returned to a new village constructed on their
atoll, Rongelap was the site of a long and thorough study of the
circulation of radionuclides in the terrestrial-aquatic environment.