[The Patterns of Behavior of Radioactive Particles in the Food Chain of Cattle and Transport in the Gastrointestinal Tract of Animals]

The analysis of the patterns of behavior of polydisperse radioactive silicate particles in the components of the food chain of cattle is presented. It is shown that the composition of the size distribution of radioactive particles taken into animal organisms differs from the original composition of the particles deposited on the surface of pasture vegetation, and from dispersion of the particles in the aboveground biomass of vegetation at the time of grazing. The intake of particles into animal organisms is reduced with the increase of their size, and for the particle fraction of 400-800 microns it is about 10 times less than for the fine fraction (100 microns). The mathematical compartment model ofthe transport of polydisperse radioactive particles in the digestive tract of cattle has been developed. It is found that the elimination rate of radioactive particles from the animal organism depends on their sizes. Deposition of particles on the fundic surface of the wall ventral sac of rumen and reticulum as well as their long stay in comparison with the chyme in abomasum was noted. The maximum levels of irradiation are formed in these parts of the digestive tract of cattle.