title: Biological half-life and oxidative stress effects in mice with low-level, oral exposure to tritium.
abstract: Tritium ((3)H) may enter the environment from human activities, particularly at production, processing, or waste storage sites such as the Department of Energy's Savannah River Site, a former nuclear production facility in South Carolina. Understanding the dynamics and potential adverse effects of tritium in exposed organisms is critical to evaluating risks of tritium releases at such sites. Previous studies estimated the biological half-life of tritium in mice to be approximately 1.13 d; however, these laboratory studies were not conducted under environmentally realistic conditions. In this study, designed to be more representative of environmental exposure, mice were allowed to drink water containing tritium (activity about 300 Bq/ml) for a period of 2 wk. The induction of oxidative stress from tritium exposure was evaluated by comparing the activities of antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase) in exposed and control mice. From this experiment, the biological half-life of tritium was determined to be 2.26 +/- 0.04 d, almost double previous estimates. While positive controls (x-ray irradiated mice) showed responses in antioxidant enzyme activity, there was no indication of oxidative stress induction in mice exposed to tritium at this concentration.
authors.affiliation: Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina 29802, USA.
authors.forename: Angel
authors.initials: A
authors.lastname: Kelsey-Wall
authors.forename: John C
authors.initials: JC
authors.lastname: Seaman
authors.forename: Charles H
authors.initials: CH
authors.lastname: Jagoe
authors.forename: Cham E
authors.initials: CE
authors.lastname: Dallas
mesh_terms: D000284:Administration, Oral; D000818:Animals; D006207:Half-Life; D008099:Liver / Q000201:enzymology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress; D014316:Tritium / Q000493:pharmacokinetics* / Q000633:toxicity; D014875:Water Pollutants, Radioactive / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D014875:Water Pollutants, Radioactive; D014316:Tritium