-~GEniwetok 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 radivactivity in the United States from the Eniwetok tests are expected to be low. Levels of 10 or more times the normal background may be reacned in some localities at some times. However, resuit in exposure far o these increases in background will be temporary, and will below amounts which wouid affect the health of exvosed persons. As it has in the past, the Commission wili conduct extensive radiviogical monitoring operations within the United States during the test series. These operations are not conducted in the expectation of possible hazard, | but for sclentific purposes and te keen the public informed on leveis of radioactivity. Two types of monitoring sperations will be cone ducted within tne United States. One wili consist of a network of U.S. ‘eather Bureau stations, which coilect fail- out samples at selected itccations 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 maiied to the Commission's New York Health and Safety Laboratory. There, the sample is reduced to ashes,