Metabolism of technetium in goats

Abstract

The yield of 99Tc from nuclear fission is in the order of magnitude of the 90Sr and 137Cs yields. The metabolic pathways of this nucleide with its physical half life of 2.1 × 105 yr have, therefore, to be investigated for radioecological assessments; especially with respect to the wide spread application of 99mTc in nuclear medical diagnosis. Experiments with goats show that 95mTc given orally as pertechnetate is readily absorbed from the gastrointestinal tract. Excretion in milk is more than 10 times lower than that of radioiodine. The Tc-content of muscular tissues is also low and seems to be of minor importance for the pathway of this element via meat of grazing animals to man. Finally, urinary excretion of Tc in man is 20-100 times higher than in goats. Therefore, the estimation of radiation burden due to Tc-isotopes from extrapolation of radioiodine data is very conservative. © 1983.