Dose-rate effects and dose and dose-rate effectiveness factor on frequencies of chromosome aberrations in splenic lymphocytes from mice continuously exposed to low-dose-rate gamma-radiation
Dose-rate effects on chromosome aberrations in the low-dose-rate range have not been evaluated previously. The incidences of chromosome aberrations were analysed in splenic lymphocytes from female specific pathogen-free (SPF) C3H mice that were continuously irradiated with low- or medium-dose-rate (...
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Published in | Journal of radiological protection Vol. 33; no. 1; pp. 61 - 70 |
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Main Authors | , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Bristol
IOP Publishing
01.03.2013
Institute of Physics |
Subjects | |
Online Access | Get full text |
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Summary: | Dose-rate effects on chromosome aberrations in the low-dose-rate range have not been evaluated previously. The incidences of chromosome aberrations were analysed in splenic lymphocytes from female specific pathogen-free (SPF) C3H mice that were continuously irradiated with low- or medium-dose-rate (LDR, MDR) 137Cs γ rays from 56 days of age to evaluate the dose-rate effects. The dose-response relationship for the frequency of dicentric chromosome aberration at each dose rate (400 mGy 22h day, 20 mGy 22h day and 1 mGy 22h day) was obtained using age-adjusted multiple linear regression analysis assuming that the relationship can be represented by a linear or linear quadratic model and a test for the difference between the irradiated group and the non-irradiated group. Values of the linear term, shown as the slope, decreased as the dose rate was reduced from 400 mGy 22h day (18.2 mGy h−1) to 1 mGy 22h day (0.045 mGy h−1), indicating a positive dose-rate effect in the dose-rate region. The incidences of dicentric chromosomes and translocation for LDR (20 mGy day−1) were compared with those for HDR (890 mGy min−1) irradiation at each total dose to obtain the dose and dose-rate effectiveness factor (DDREF). The DDREFs were 4.5 for dicentrics and 2.3 for translocations at a total dose of 100 mGy based on the chromosome aberration rate. These results will be useful for estimating the risk of LDR radiation exposure and radiation protection. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0952-4746 1361-6498 |
DOI: | 10.1088/0952-4746/33/1/61 |