Dynamic model for the transfer of Cs-137 through the soil-grass-lamb foodchain

A dynamic radioecological model for the transfer of radiocaesium through the soil-grass-lamb foodchain has been constructed based on field data collected in 1990 from the Nordic countries. The model assumes an initial soil contamination of one kilobecquerel of 137Cs per square metre and simulates the transfer to grass through root uptake in addition to direct contamination from resuspended activity. The model covers two different soil types: clay-loam soil and organic soil, between which there are significantly different transfers of radiocaesium to grass. The implementation of the metabolism of the lamb includes an assumption of a biological half-life of three weeks for radiocaesium in the meat. The model gives a good representation of the input data on which it is based. (au) (10 refs.)