Factors affecting radiocaesium transfer to ruminants

The first phase of a 2-year programme is described, involving 9 laboratories in 6 countries. A number of experiments have used the true absorption coefficient to measure uptake in the gut of ruminants. The technique involves the dual administration of two isotopes of radiocaesium. Transfer of dietary radiocaesium across the gut wall can then be calculated taking endogenous excretion into account. Other integrated aspects of the study include measurements of the soil adhesion to pasture grass and fodder. Allied to this study the availability of radiocaesium in different types of soil for absorption in the gut is being measured. The objectives and results of three topic areas, involving nine contributions of the project for the reporting period are presented. (R.P.) 14 refs., 8 figs., 3 tabs