RADIATION SURVEYS OF SEA AND MARINE LIFE Outside of the testing area, the detonations are not expected to produce levels of radioactivity in the ocean which would be hazardous to marine life or to persons eating food fish. However, an extensive program of measurements of radioactivity in the sea water and in marine organisms will be conducted. Beginning about June 10, a fast U. S. Navy vessel will work westward from the test site, making sweeps between 10 and 14 degrees North latitude west as far as fallout radioactivity can be detected. Continuous readings of radioactivity in the surface water will be taken by means of a device which pumps water around a detection instrument in a tank on the deck of the ship. The ship will stop each 25 miles to take samples of the water at the surface and at depths of 25, 50, 75 and below 100 meters. Personnel aboard the ship also will make tows for plankton-tiny marine organisms which tend to concentrate radioactive materials in their tissues. Fish will be caught, and analyzed for radioactivity. FALLOUT MONITORING IN UNITED STATES The heavier particles fall out of the radioactive cloud at early times after a detonation, while their radioactivity is still high. Therefore, the highest levels of radioactivity occur over a local area downwind from the point of detonation. The area of significant fallout is expected to occur entirely within the uninhabited danger area surrounding the Eniwetok Proving Ground. As the radioactive cloud is transported away from the point of detonation, it is widely dispersed by air currents and diluted by normal air. Its radioactivity also decreases rapidly because of the normal process of radioactive decay. By the time the cloud from an Eniwetok test has traveled eastward across the ocean, it will have become a dispersed, invisible air mass, which has lost much of its original radioactivity. As a result, the levels of radioactivity in the United States from the Eniwetok tests are expected to be low. Levels of 10 or more times the normal background may be reached in some localities at some times. However, these increases in background will be temporary, and will result in exposure far below amounts which would affect the After the series, when test radioactivity will have moved further away from the test site, a similar survey will be carried out as far west as radioac-health of exposed persons. tivity can be detected. The Commission also has entered into a contract with the George Vanderbilt Foundation at Stanford University, under which scientists will collect samples of water, plankton, marine invertebrates and fish in the vicinity of the Palau Islands. These samples will be sent to the biological laboratory at the Hanford Works for analyses. In addition to these investigations, land and marine biological surveys will be conducted on Eniwetok and Bikini Atolls and in their lagoons. Samples of water, lagoon life, and animal life on the atolls will be collected and analyzed for radioactivity. As it has in the past, the Commission will conduct extensive radiological monitoring operations within the United States during the test series. These operations are not conducted in the expectation of possible hazard, but for scientific purposes and to keep the public informed on levels of radioactivity. 2 Radioactive fallout consists of a mixture of radioisotopes, with varying half-lives. The mixture as a whole decreases in radioactivity in such a way that for every seven fold increase in age, the total radioactivity is decreased 10-fold. Thus, the radioactivity at seven hours after the explosion is only one-tenth that at one hour, and in 49 hours is one-hundredth, etc. Two types of monitoring operations will be conducted within the United States. One will consist of a network of U. S. Weather Bureau stations, which collect fallout samples at selected locations throughout the nation. The collection method is simple. A sheet of film covered with an adhesive is exposed outdoors on a tray for 24 hours, and then is mailed to the Commission's New York Health and Safety Laboratory. There, the sample is reduced to ashes, and the ashes are monitored with sensitive laboratory instruments. Very minute amounts of radioactivity can be measured by this technique. During the 1956 series, the following Weather Bureau stations will make fallout collections: Albuquerque, N. Mex. Billings, Mont. Binghamton, N. Y. Boise, Idaho Boston, Mass. Chicago, Ill. Cincinnati, Ohio Cleveland, Ohio Concord, N. H. Grand Junction, Colo. Memphis, Tenn. Miami, Fla. Minneapolis, Minn. New Haven, Conn. New Orleans, La. New York (La Guardia), N. Y. St. Louis, Mo. Salt Lake City, Utah San Francisco, Calif. San Juan, P. R. Washington, D. C. (Silver Hill, Md.) This collection system does not provide immediate information on dose rates, since the samples must be mailed to the Health and Safety Laboratory and counted there. However, the information collected has varied scientific uses. It is needed by the Commission to compute and record the overall accumulation of radioactivity as a result of tests. It is needed by the photographic industry and by scientists conducting experiments with low-level radiation, since these activities can be affected by even a very slight increase over the normal background. The data also are used by meteorologists to trace air masses and check predicted trajectories. More rapid information on radiation levels will be provided by 39 monitoring stations located in cities across the country. Twenty-seven of these stations have been set up by the U. S. Public Health Service, which has been furnishing fallout monitoring services to the Commission for the past two years in States near the Nevada Test Site. At the Commission's request, the Public Health Service has established an expanded monitoring program which will be in operation with the forthcoming test series. The monitoring stations established by the Public Health Service will collect daily readings of radioactivity and forward the data to a central collection office in Washington. The monitoring stations also will report data to the State Health Officers of the States in which the stations are located. The primary purposes of the network are to give State and local health departments more experience in studying fallout and normal background radia tion levels, and to obtain daily records of radioactivity. The stations will be manned by trained technicians from State health departments, local universities, and scientific institutions. Monitoring stations in the Public Health Service network will be located in the following cities: Lawrence, Mass. Hartford, Conn. Albany, N. Y. Bethesda, Md. Gastonia, N. C. Jacksonville, Fla. Salt Lake City, Utah Trenton, N. J. In addition to the Public Health Service network, monitoring stations set up by the Commission will collect data at 12 locations, listed below: Atomic Energy Project, University of California at Los Angeles Sandia Corporation, Sandia, N. Mex. Idaho Operations Office, U. S. Atomic New York Operations Office, U. S. MEASUREMENTS OF RADIOACTIV- Samples of airborne dust will be taken at approximately 70 various localities throughout the world, in addition to the 41 U. S. stations. Previous studies of this kind have shown that the average gamma ray dosage delivered to world inhabitants by all tests to date is less than the dose they have received from natural background radiation during the same period of time. All of these dosages are believed by radiologists and radiobiologists to be harmless. Radiostrontium-90 has been demonstrated to be potentially the most hazardous of bomb products which compose airborne dust or fallout. As in the past, soils will be sampled on a world-wide basis, and samples of other materials such as milk and cheese, field crops, and human and animal bones, will be taken for analysis of their radiostrontium content. These sam Atomic Energy Project, Salt Lake plings are carried out, together with City, Utah University of California Radiation radiochemical analysis, for a 2-fold purpose: 1) ascertain the world-wide distribution of radioactive fission prod Argonne National Laboratory, Le- ucts-particularly strontium-90-in the mont, Ill. air, water and soils of the earth as a Atomic Energy Project, Rochester, result of atomic tests to date; 2) to N. Y. ascertain the relationship of man to his Los Alamos Scientific Laboratory, environment, particularly as regards Los Alamos, N. Mex. General Electric Co., Aircraft Nuclear Propulsion Dept., Evendale, Ohio strontium-90. These observations, when combined with studies on the biological hazards of strontium-90, have disclosed that nowhere in the Oak Ridge National Laboratory, Oak world are there concentrations of this Ridge, Tenn. isotope remotely approaching hazard ted to the Task Force Headquarters. ous amounts. The average concentra- | will be obtained rapidly and transmittion observed in human bone is less than 1/10,000 of the concentration which might be expected to show ill effect on human beings. The highest concentrations found in any individuals are less than ten times the average. SUMMARY Elaborate precautions are being taken to limit significant fallout to the uninhabited danger area surrounding the Eniwetok Proving Ground. Information on radioactivity on inhabited atolls in the Marshall Islands Should there be significant fallout on an inhabited atoll, monitors will advise the inhabitants regarding basic emergency measures, and the inhabitants could be moved away from the atoll quickly if such action were considered necessary. Ocean water and marine life will be analyzed for radioactivity, and measurements of radioactivity will be taken within the United States and in other parts of the world. Levels of radioactivity outside the danger area are expected to be far below those which would be hazardous to exposed persons. May 1, 1956 U. S. GOVERNMENT PRINTING OFFICE, 1986 |