Gamma radiation at a human relevant low dose rate is genotoxic in mice.
Even today, 70 years after Hiroshima and accidents like in Chernobyl and Fukushima, we still have limited knowledge about the health effects of low dose rate (LDR) radiation. Despite their human relevance after occupational and accidental exposure, only few animal studies on the genotoxic effects of chronic LDR radiation have been performed. Selenium (Se) is involved in oxidative stress defence, protecting DNA and other biomolecules from reactive oxygen species (ROS). It is hypothesised that Se deficiency, as it occurs in several parts of the world, may aggravate harmful effects of ROS-inducing stressors such as ionising radiation. We performed a study in the newly established LDR-facility Figaro on the combined effects of Se deprivation and LDR γ exposure in DNA repair knockout mice (Ogg1(-/-)) and control animals (Ogg1(+/-)). Genotoxic effects were seen after continuous radiation (1.4 mGy/h) for 45 days. Chromosomal damage (micronucleus), phenotypic mutations (Pig-a gene mutation of RBC(CD24-)) and DNA lesions (single strand breaks/alkali labile sites) were significantly increased in blood cells of irradiated animals, covering three types of genotoxic activity. This study demonstrates that chronic LDR γ radiation is genotoxic in an exposure scenario realistic for humans, supporting the hypothesis that even LDR γ radiation may induce cancer.
Department of Chemicals and Radiation, Norwegian Institute of Public Health, Oslo 0403, Norway.|Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Anne
A
Graupner
Department of Chemicals and Radiation, Norwegian Institute of Public Health, Oslo 0403, Norway.|Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Dag M
DM
Eide
Department of Chemicals and Radiation, Norwegian Institute of Public Health, Oslo 0403, Norway.|Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Christine
C
Instanes
Department of Chemicals and Radiation, Norwegian Institute of Public Health, Oslo 0403, Norway.|Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Jill M
JM
Andersen
Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.|Department of Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Dag A
DA
Brede
Litron Laboratories, Rochester, NY 14623, United States.
Stephen D
SD
Dertinger
Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.|Department of Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Ole C
OC
Lind
Department of Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Anicke
A
Brandt-Kjelsen
Department of Monitoring and Research, Norwegian Radiation Protection Authority, Østerås 1332, Norway.
Hans
H
Bjerke
Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.|Department of Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Brit
B
Salbu
Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.|Department of Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU), Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Deborah
D
Oughton
Department of Chemicals and Radiation, Norwegian Institute of Public Health, Oslo 0403, Norway.|Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Gunnar
G
Brunborg
Department of Chemicals and Radiation, Norwegian Institute of Public Health, Oslo 0403, Norway.|Centre for Environmental Radioactivity (CoE CERAD), Ås 1432, Norway.
Ann K
AK
Olsen
D000818:Animals; D001773:Blood Cells / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects*; D045647:DNA Glycosylases / Q000502:physiology* / Q000528:radiation effects; D004260:DNA Repair / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects*; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation; D018384:Oxidative Stress / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D012643:Selenium / Q000172:deficiency
D017382:Reactive Oxygen Species; D045647:DNA Glycosylases; C485990:Ogg1 protein, mouse; D012643:Selenium