title: Persistence and prediction of radiocaesium levels in animals grazing semi-natural environments.
abstract: In vivo monitoring of radiocaesium levels in a flock of mountain sheep grazing a heather-dominant peatland ecosystem was undertaken over a 3-year period from 1989 to 1991. Highest values were observed during summer and autumn and measurable radiocaesium activities were present throughout the year. Comparably high mean and maximum values recorded in November 1989 are thought to be a result of fungi consumption. Analysis of variance indicated that an increase of 4% occurred in radiocaesium levels in muscle between 1989 and 1990 followed by an overall decrease of 35% between 1990 and 1991. In order to test an existing model to predict radiocaesium levels in muscle from measured activities in faeces, an independent data set was produced. The radiocaesium content of faecal samples collected from the grazing range of a sheep flock was compared with the results of in vivo measurements on the same animals. The correlation over time between the predicted and observed flock mean and maximum values was found to be significant, thereby confirming the value of faeces sampling as an inexpensive and rapid means of assessing the distribution of radiocaesium activities in sheep flocks grazing semi-natural ecosystems.
authors.affiliation: Radiological Protection Institute of Ireland, Dublin.
authors.forename: E J
authors.initials: EJ
authors.lastname: McGee
authors.forename: H J
authors.initials: HJ
authors.lastname: Synnott
authors.forename: M
authors.initials: M
authors.lastname: Keatinge
authors.forename: P A
authors.initials: PA
authors.lastname: Colgan
mesh_terms: D000818:Animals; D002588:Cesium Radioisotopes / Q000032:analysis* / Q000493:pharmacokinetics; D005243:Feces / Q000737:chemistry*; D005260:Female; D008954:Models, Biological; D009132:Muscles / Q000737:chemistry*; D011847:Radioactive Fallout; D012621:Seasons; D012756:Sheep
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout