Historical Estimates of External γ Exposure and Collective External γ Exposure from Testing at the Nevada Test Site. II. Test Series After Hardtack II, 1958, and Summary

The historical data on the cumulative individual external y exposures are tabulated for communities around the Nevada Test Site for the time periods of 1961 to the signing of the Limited Test Ban Treaty on 5 August 1963, and from then until 1975. The collective exposures during the two time periods are calculated to be 610 and 320 person-R† respectively. The total collective external γ exposure from 1951 through 1975 for these communities is calculated to be 86,000 person-R. The area considered includes the counties of Clark, Lincoln, Nye, and White Pine in Nevada and the counties of Iron and Washington in Utah; inclusion of Salt Lake City would have substantially increased the calculated collective exposure because of the large population. The methods of calculation are reviewed. Also, the historical data on the assessment of dose via ingestion are reviewed with emphasis on the dose to the thyroid of infants living in St. George, Utah, at the time of fallout from event HARRY on 19 May 1953.