Assessment of iodine-131 transfer to cow's milk and to man resulting from the Nevada weapons tests of the 1950's

The main pathway to man from fallout I-131 is, for most individuals, via the grass-cow-milk chain. In order to assess I-131 exposures for persons in each county of the contiguous U.S. the following estimates must be made : the activities of I-131 deposited on soil and pasture grass, the resulting I-131 concentrations in cow's milk, and the quantity of I-131 ingested by man. The most significant atmospheric weapons tests with respect to fallout occurred in the 1950's, during which time most of the monitoring of environmental radioactivity consisted of gross beta or gamma measurements. Assessments of exposures due to I-131 can be inferred from the original measurements of gross beta or gamma activity, from current or past measurements of radionuclides other than I-131, or from mathematical models