title: Chronic exposure to gamma radiation of wild populations of meadow voles (Microtus pennsylvanicus).
abstract: Free-ranging, wild meadow voles (Microtus pennsylvanicus) were exposed to gamma radiation from a (137)Cs irradiator in a series of experiments conducted on six 1-ha meadows within a mixed deciduous forest in Manitoba, Canada. Over a period of 1-1.5 years in each of three experiments, vole populations were monitored with capture-mark-release techniques at nominal exposure rates of 200x, 9000x and 40,000x background. No effects on population or individual characteristics were detected up to the highest exposure rate (81 mGy/d). At this level, third generation voles were monitored up to a lifetime dose of about 5.7 Gy, at a measured dose rate of 44 mGy/d. Smaller numbers of overwintered animals survived and reproduced normally at doses up to 10 Gy. These results are discussed in terms of low-LET, external chronic radiation effects on rodents in the laboratory and the field, relative to current views on appropriate benchmarks for the protection of biota.
authors.affiliation: Canadian Nuclear Safety Commission, PO Box 1046, Station B, Ottawa, Ont., Canada K1P 5S9. mihoks@cnsc-ccsn.gc.ca
authors.forename: Steve
authors.initials: S
authors.lastname: Mihok
mesh_terms: D000818:Animals; D000835:Animals, Wild; D003411:Arvicolinae; D002588:Cesium Radioisotopes / Q000032:analysis; D004781:Environmental Exposure; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects*; D008297:Male; D011157:Population Dynamics; D012098:Reproduction; D012621:Seasons
chemical_list: D002588:Cesium Radioisotopes