Biological Inventories
Familiarity with the biological components of an ecosystem is essential to meaningful radiobiological assessment.
Inventories of natural components were not made in the early nuclear test programs because of inadequate realization of the biological potential. Later, they could be made only after radionuclides already had been introduced into the environments.
The survey of the mid-Pacific region before Operation Crossroads represented the earliest effort to examine an environment in detail before a nuclear detonation, but was designed so that it had only inferential value for other long-range biological research. The test surveys were useful, however, in expanding knowledge of specific environments. In addition, it was standard practice to make comparative collections of organisms in regions removed from the test sites to establish base lines, or “controls”, against which to measure radiobiological developments.
The most extensive inventory of an environment—an inventory designed specifically in relation to an anticipated nuclear detonation—was that made between 1959 and 1962, as a preliminary phase of Project Chariot, in the Cape Thompson area of Northwest Alaska. Chariot was a part of the AEC Plowshare Program in which it was proposed to excavate a harbor at the mouth of the Ogotoruk Creek, which empties into the Chukchi Sea. Although the excavation project actually never was undertaken, the “predetonation” environmental investigations involved 3 years of coordinated research into the climatic, marine, coastal, and terrestrial aspects of the region, and detailed studies of the history and the radiological and ecological situations of the human population.
Taking a soil sample for the Project Chariot biological inventory to determine kinds and relative abundance of invertebrates and other soil organisms.
The program was an effort to make a model environmental inventory. Its significance was both in its assessment of the base for determining the “biological cost” of the proposed operation and in the thoroughness of its documentation of the environmental features of a part of the world that previously had been virtually unexplored. It was a prototype for future studies.
Measurements and Interpretations
Determination of the amounts and kinds of radioactivity in a biological sample is a process wholly dependent on instruments, since radiation usually cannot be detected by the senses.