Report of Surveilance
CENTRAL INTELLIGENCE AGENCY - September 9, 1949
Samples of air masses recently collected over the North Pacific have shown an abnormal radio-active contamination. The first sample, secured 3 September, and the latest sample, secured 7 September, show radioactive material in concentrations greatly exceeding the normal radio-active content of the atmosphere. Such a high concentration has not been observed since the Eniwetok tests in August 1948.
This condition may have been caused by one or a combination of several things:
- An atomic explosion on the continent of Asia;
- Volcanic activity on the continent of Asia or in the islands North of Japan;
- Radio-active gases from the Hanford, Washington plant being swept cut first to the westward by low-traveling easterly winds and then on rising to the atmosphere, being carried back east again by the prevailing westerlies;
- Waste or an explosion at an atomic bomb plant in Russia.
Conventional intelligence reports indicate volcanic activity on 2 September at a point in the North Japanese Islands. This volcanic radio-active _________ very well could have entered the air at this point.
This report has received only extremely limited distribution because there has been no confirmation of any man-made atomic explosion at this time. Meanwhile, we are attempting to get confirmation on exactly what might have occurred.
Until further confirmation is obtained, it is requested that this report be treated and held with exercise caution.
Rear Admiral, USN
Director of Central Intelligence