Abstract
This paper reports the effects of changes in dose-rate and dose-fractionation on the micronucleus (MN) yield in human lymphocytes exposed to 250 kV X-rays. For the investigation of dose-rate effects whole blood samples of four healthy donors were irradiated with doses ranging from 1 to 4 Gy given at various dose-rates between 0.2 and 40 Gy/h. For the higher doses (3 and 4 Gy) a decline in the MN yield became apparent when the dose-rate was reduced below 1.6 Gy/h. This effect was enhanced systematically by a further lowering of the dose-rate. For lower doses (1 and 2 Gy) the reduction in the MN yield was less pronounced: only a small effect was observed for two donors when a dose of 2 Gy was administered at a dose-rate of 0.2 Gy/h. In the split-dose experiment a dose of 4 Gy was delivered either as a single exposure or in two fractions of 2 Gy, separated by time intervals ranging from 30 min to 10 h. A continuous decrease of the MN yield with increasing interfraction time is observed: after an initial fast decline a further slight reduction in the MN yield occurs. The observed dose-rate and split-dose effects on the MN yield can be attributed to repair of sublethal damage.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
