Measurements of transfer coefficients for 137Cs, 60Co, 54Mn, 22Na, 131I and 95mTc from feed into milk and beef.

The transfer in cattle of the radionuclides 137Cs, 60Co, 54Mn, 22Na, 131I and 95mTc was studied experimentally to determine transfer coefficients from feed to milk and meat. Special interest was kept on normal feeding and maintenance conditions used in Germany. The radionuclides were incorporated into fodder plants through root uptake and thus available in a chemical form resulting from the contamination of agricultural soil. This permitted realistic simulation of the soil-plant-animal food chain. The equilibrium transfer coefficients for milk were calculated to be 22Na: 0.016 +/- 0.002 d/l, 60Co: less than or equal to 0.0002 d/l, 54Mn: less than or equal to 0.0005 d/l, and 137Cs: 0.0022 +/- 0.0002 d/l. The equilibrium transfer coefficients for meat were calculated to be 22Na: 0.01 +/- 0.002 d/kg, 60Co: less than or equal to 0.00013 d/kg, 54Mn: less than or equal to 0.0005 d/kg, and 137Cs: 0.0062 +/- 0.0006 d/kg. A single dose of 131I was orally administered three times in the chemical form of iodide. Models were applied to obtain parameters for a quantitative description of the iodine metabolism. The equilibrium transfer factor for 131I in this chemical form to milk was calculated to be 0.009 +/- 0.0014 d/l. For 95mTc only an upper limit of the transfer factor of 1.7.10(-4) d/l could be estimated because of the small amount of radioactivity available.