Date

Jun 1, 1951

Description

Open-Net provides details on this report, but like the previous UCLA study, DOE has yet to provide a PDF. Based on 1949 and 1950 radiological surveys of soil and plant life and their interrelations, this detailed report included disquieting findings concerning the residual radioactivity of the Trinity Fall-out. For example, “measurable amounts of radioactive fission products ... still are present” in the Ratliff area (near the “Hot Canyon”), the Chupadera Mesa, and “Area 21” (28 miles northeast of Zero). On the Mesa, radioactive contamination was “still concentrated in the upper one or two inches of soil,” while “downward migration of the radioactive fission products may be taking place.” Further, “the relatively greater uptake observed in 1950, compared to 1949, points out that as a potential biological hazard the remaining … fission product contamination of the Chupadera Mesa is relatively greater now than in the past.”

The researchers found “no hazard from external total body exposure to penetrating ionizing radiation (gamma rays) exists any place outside of the Fenced Area,” but they would not “assume at this point that that no hazard exists outside of the Fenced area from the widespread fission product contamination.” In addition, outside the Fenced Area there are “many potential long term insidious hazards from the present low level contamination which is the focal point of these studies.” Evidence from the annual biological surveys was “beginning to accumulate … that such hazards exist.”

The degree of danger, specifically the “absence, presence, or magnitude of the biological hazard” was nevertheless indeterminate because the area was in “flux.” Before conclusions could be drawn, annual surveys and related laboratory research were necessary to “determine the mechanisms by which the long and medium half-life fission products and the important alpha emitters are absorbed and metabolized by important crops and animals.”

Source

University of New Mexico, Center for Southwest Research Szasz Papers, Box 14, Folder 5, Field Reports of Trinity, 1951

Document published in following posting(s):

The First Atomic Explosion, 16 July 1945

Jul 16, 2024

K.H. Larson et al., “The 1949 and 1950 Radiological Soil Survey of Fission Product Contamination and Soil-Plant Interrelationships of Areas in New Mexico Affected by the First Atomic Bomb Detonation (Trinity),” UCLA-140, 12 June 1951, Confidential, Excerpts