Transfer of some Chernobyl fallout nuclides in the animal-product food chain

One of the most important tasks after the Chernobyl accident was the tracing of radionuclides into the food chain because of the acute interest in view of radiation protection considerations and of the fundamental significance to extend the knowledge on consequences of an accidental release. In this context five experiments have been performed during the last two years to investigate the transfer of radiocesium from grass into milk and meat of dairy cows. The first experiment, which was started immediately after the accident, involved 10 stable-kept cows fed with the freshly contaminated grass. Cs-transfer from grass into milk was found to be considerably lower than expected. After the starting phase of one week the mean transfer factor milk/grass for Cs-134 and Cs-137 leveled at 3.2.10-3 d/kg during the second week. This interesting result gave rise to four additional experiments, to study the Cs-transfer during the following feeding periods applying grass of fallout and root-uptake contamination