Life shortening in mice exposed to fission neutrons and gamma rays. VIII. Exposures to continuous gamma radiation

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3577430· OSTI ID:6097055

Thomson, J F; Grahn, D

Data are presented on the mean aftersurvival of male B6CF1 mice exposed for 22 h per day, 5 days per week, to /sup 60/Co gamma radiation at dose rates of 1.36 to 12.64 x 10(-3) cGy/min for 23 weeks or 1.36 to 6.32 x 10(-3) cGy/min for 59 weeks. For deaths from all causes, linear dose-response curves were obtained with slopes (days of life lost/cGy) of 0.158 +/- 0.016 and 0.077 +/- 0.002 for 23- and 59-week exposures, respectively. These values were not significantly altered when the analysis was restricted to those mice dying with tumors (92% of the total) or to those presumably dying from tumors (82% of the total). Analysis of mortality rates showed that about 90% of the radiation-specific excess mortality was tumor related. The 59-week exposure series induced only a small increase in the number of days of life lost/cGy/weekly fraction over that induced by 23 weeks of irradiation, 4.53 +/- 0.15 compared to 3.64 +/- 0.36 days lost/cGy/weekly fraction. This lower than expected value for 59 weeks of exposure may signal the approach to the final linear, additive, injury term postulated from earlier studies at this laboratory with low-dose-rate, daily, duration-of-life /sup 60/Co gamma irradiation.

• Research Organization: Argonne National Lab., IL (USA)
• OSTI ID: 6097055
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 118:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
COBALT 60
COBALT ISOTOPES
DISEASES
DOSE-RESPONSE RELATIONSHIPS
DOSES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
FISSION NEUTRONS
GAMMA RADIATION
HADRONS
INJURIES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
IRRADIATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LOW DOSE IRRADIATION
MAMMALS
MICE
MINUTES LIVING RADIOISOTOPES
NEOPLASMS
NEUTRONS
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
RADIATION DOSES
RADIATION EFFECTS
RADIATION INJURIES
RADIATIONS
RADIOISOTOPES
RODENTS
SURVIVAL TIME
TOXICITY
VERTEBRATES
YEARS LIVING RADIOISOTOPES