RADIOIODINE UPTAKE IN NATIVE ANIMALS AT THE NRTS AND ENVIRONS.

Abstract

Abstract—The National Reactor Testing Station has a fair ground cover of sagebrush, rabbit brush, and perennial grass, and a good population of native animals which are utilized in the environmental monitoring program. Research and biological monitoring are conducted in those situations where small amounts of radioiodine are released into the environment through routine operations and special reactor tests. Various species of native animals were analyzed for I131 uptake while living in their native habitat and under laboratory conditions. In each case the uptake and the biological effective half-life of I131 in the thyroid was determined with the following results: Table 1 . Species Per cent uptake at day one Effective half-life (days) Jack rabbit 29 2 Chipmunk 80 6 1/2 Kangaroo rat 80 7 Year-to-year comparisons were made of stack releases of I131 from the chemical fuel-processing plants and the amount of I131 found in the animals at different downwind distances. The quantity of radioiodine found in the animal thyroid has proven to be an extremely sensitive indicator of area contamination not only from local sources but also from nuclear weapons testing.