nt is , BIOLOGY AND MEDICINE UNCLASSIFIED =: States, including New York, Pittsburgh, Chicago, Denver, the Colorado Plateau, Arkansas, and Tennessee. The only significant departures from New York City natural background (7 to 11 microroentgens per hour) were found in three regions: the Dakotas, where backgrounds were approximately three times the natural New York background; Denver, Colorado, where background was approximately twice that of New York; and a 50-mile stretch on either side of U. S. Highway 70 between the towns of Carlisle and Palestine in Arkansas, where radiation levels were 5 to 15 times the normal New York background. Measurements taken nine days later in the Arkansas area showed a 75 percent decrease in background. One month after the original measurement, radiation levels in the Black Hills of South Dakota showed almost a 50 percent reduction. Measurements taken over two months later in the Denver area showed that radiation levels had decreased about 20 percent. These lower levels indicate that in each case at least part of the original background radiation was attributable to radioactive fallout from test activities. The Colorado Plateau showed a generally higher background than the nationwide average. This was to be expected because of the higher uranium content of many of the rocks of the area and because of the higheraltitude. Approximately 40 bricks from eight different parts of the country were received for study. Preliminary measurements indicated that whereas different types of bricks from the same location show only slight differences in radioactivity, there is a range of approxi- mately three to one in the radiation measured from bricks of different localities. This study is being continued. VISIT TO MARSHALL ISLANDS Dr. C. L. Dunham, Director of the Division of Biology and Medicine, visited Rongelap Atoll during the month of September. The people had been back on their island for two months and had made a good adjustment. The new housing and community buildings are very satisfactory. The recently installed two-way radio saved two lives by permitting prompt transfer of two serious emergency cases to the hospital at the Kwajalein Naval Station. Plans were begun for the next annual medica) survey, to take place in March 1958, four years after exposure. This will be the fifth examination conducted, and it will be enlarged in scope. Extensive studies will be carried out similar to those of the last survey, with considerable emphasis on hematological investigations and on growth and developmentof the wey A ue orRI erate sd tieer ioe csrie A children, as well as on long-term effects of radiation. In addition, a whole-body gammacounting facility will be utilized for special studies on whole-body gamma spectroscopy and radiochemical analyses of the urine to determine whether the Rongelapese have any appreciable body burden of radioisotopes. It is anticipated that this device will be used repeatedly on the Marshallese in future annual surveys. (End of UNCLASSIFIED section.) . UNCLASSIFIED 1113292 Pen orse eaEc & .