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RADIATION EXPOSURES IN RECENT WEAPONS TESTS
Prior to the recent weapons tests a danger zone was established sur-
rounding the proving grounds; within this area a hazard from radiation might exist to shipping or aviation. Appropriate notices on the
boundaries and the establishment of the danger zone were carried in
marine and aviation navigational manuals. Before each shot of the
series, a careful survey was made of the windsat all elevations up to
many thousands of feet, and survey aircraft searched the area for
shipping. The purpose was to take every precaution against radiation
exposure of inhabitants of the area, the task-force personnel, and crew
or passengers of vessels or aircraft.
During the tests, radiological monitoring teams were set up and the
monitoring network of stations as usual was in operation to collect
and measure fall-out—radioactive particles from the explosion descending to the lower atmosphere, the sea, or the earth. Measurements were made of airborne, ground, and water activity. The only
fall-out of consequence was that which followed the first detonation of
March 1, when a shift of the winds occurring after the detonation
carried radioactive particles toward the islands of Rongelap, Rongerik,
and Utirik. Thirty-one American test personnel, and 236 Marshallese
were exposed to radiation. A Japanese fishing trawler, the Fukuryu
Maru (Fortunate Dragon) was also in the path of fall-out.
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Evacuation of Test Personnel
The 31 Air Force, Army, and Navy fest personnel were evacuated to
Kwajalein for physical examinations and observations. None of the
men experiencetl any symptomsofradiation illness, and medical ob-
servations to date do not indicate that any permanent harm has re-
sulted. All of the men included in this group were returned to military duty following complete physical examinations at Tripler Gen-
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Inhabitants ofMarshall Islands
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The Marshallese from theislands of Rongelap and Utirik within the
area of fall-out following the first detonation were evacuated promptly
by the Task Force to Kwajalein. It was found that of the 236 evacuated, 74, all from Rongelap, experienced radiation burns, principally