title: Does low dose internal radiation increase lifespan?
abstract: No significant differences in lifespan could be established between control dogs and dogs given 241Am, 228Th, 90Sr, 228Ra, 226Ra or monomeric 239Pu at low dosage levels that induced less than 10% skeletal malignancies (low dose animals) in the Utah beagle colony when all dogs surviving at least 1 y were included in the analysis and dogs given individual radionuclides were considered separately or together. Censoring or exclusion of dogs from these groups that were diagnosed with skeletal malignancies or that died in a gran mal epileptic seizure made no important difference to these results. Therefore, an enhanced lifespan of low dose dogs as compared with controls could not be established. It is concluded that low doses from internal (mainly skeletal) deposits of these radionuclides probably do not benefit the survival of individuals so exposed.
authors.affiliation: Radiobiology Division Department of Radiology, University of Utah School of Medicine, 729 Arapeen Drive, Salt Lake City, UT 84108-1218, USA. ray.lloyd@hsc.utah.edy
authors.forename: Ray D
authors.initials: RD
authors.lastname: Lloyd
authors.forename: Glenn N
authors.initials: GN
authors.lastname: Taylor
authors.forename: Scott C
authors.initials: SC
authors.lastname: Miller
mesh_terms: D000818:Animals; D001822:Body Burden; D001859:Bone Neoplasms / Q000401:mortality*; D004195:Disease Models, Animal; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D005260:Female; D007267:Injections; D008136:Longevity / Q000528:radiation effects*; D008297:Male; D008954:Models, Biological; D009381:Neoplasms, Radiation-Induced / Q000401:mortality*; D016016:Proportional Hazards Models; D011829:Radiation Dosage; D011868:Radioisotopes / Q000008:administration & dosage* / Q000032:analysis*; D011874:Radiometry / Q000379:methods*; D012016:Reference Values; D018570:Risk Assessment / Q000379:methods*; D017678:Sex Distribution; D016019:Survival Analysis; D015996:Survival Rate
chemical_list: D011868:Radioisotopes