Estimate of terrestrial radiation exposure based upon aerial surveys

During the period from 1958 to 1963 aerial radiological surveys (ARMS) were conducted over approximately 25 areas in the vicinity of nuclear facilities in the USA. The population of each survey area was estimated from U.S. census data. It was found that approximately 30 percent of the U.S. population (1960 Census) resided in the survey areas, and thus it was concluded that the ARMS data would be potentially useful for making exposure estimates. The surveys were intended to provide information on radiation levels in the vicinity of nuclear installations, so that future releases of radioactive material to the environment from the facilities could be detected. In general, the facilities occupy considerably less than 1 percent of the surveyed areas, and there were no reported or obvious patterns of radionuclide deposition around the facilities. Estimates were made of the radiation dose to human populations in the areas from terrestrial γ sources of natural and man-made radiation. (U.S.)