Absorption of radiocaesium by sheep after ingestion of contaminated soils

Gastrointestinal fractional absorption of radionuclides in adult domestic ruminants

“…1) and transfer from the gastrointestinal tract to the circulatory system has been shown to be source dependent. Studies orally administering soil-associated radiocaesium to sheep have estimated A t values in the range 2.0 Â 10 À2 -0.19 (Cooke et al, 1996;Beresford et al, 2000a). In one study, the same contaminated soil was administered to both cattle and sheep (Mayes et al, 1993;Beresford et al, 2000a) but the A t value determined for cattle (0.2) was an order of magnitude higher than that determined in sheep.…”

The transfer of radionuclides from saltmarsh vegetation to sheep tissues and milk

“…The availability of 137 Cs associated with silt from the Ravenglass Estuary for absorption in the ruminant gut has previously been shown to be <10% of that for Cs incorporated into vegetation or ingested as CsCl (see review by Beresford et al, 2000). Apart from Cs there is only limited evidence to suggest that the availability for absorption in the ruminant gut of Am and Pu from saltmarsh vegetation and soil contaminated by marine discharges from the Sellafield reprocessing plant is low compared to 'recommended' values (see Ham et al, 1989;Harrison, 1991;Cooke et al, 1997).…”

Radiocaesium variability within sheep flocks: determination of 137 Cs intake in free-ranging sheep

“…For instance, ingested soil can contribute considerably to the radiocaesium intake of grazing animals [23]. The bioavailability of radiocaesium from a number of different soils has been shown to be considerably lower than of radiocaesium incorporated into vegetation via root uptake [21,24]. Consequently, when soil ingestion represents a large proportion of the dietary radiocaesium intake, a lower A a value would be expected.…”