Dose and dose-rate dependence of mutation frequency under long-term exposure – a new look at DDREF from WAM model. Issue 11 (1st November 2016)

• Record Type: Journal Article
• Authors: Wada, Takahiro; Manabe, Yuichiro; Nakamura, Issei; Tsunoyama, Yuichi; Nakajima, Hiroo; Bando, Masako
• Is Part Of: Journal of nuclear science and technology. Volume 53:Issue 11(2016)
• Page Start: 1824
• Page End: 1830
• Publication Date: 2016-11-01
• Subjects: Dose rate -- mutation -- LNT hypothesis -- DDREF -- mathematical model -- long-term exposure -- radiation protection -- radiation damage; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2016.1164635
• Languages: English
• ISSNs: 0022-3131

Abstract

ABSTRACT: We have investigated the dependence of the mutation frequency on the dose and dose rate of artificial radiation using the Whack-A-Mole (WAM) model that we recently proposed. In particular, we pay special attention to the case of long-term and low-dose-rate exposure. Our results indicate that the WAM model successfully describes the dose-rate dependence, and it can replace the so-called dose and dose-rate effectiveness factor (DDREF), which has been used for long, to account for the differences between high-dose-rate and low-dose-rate data. The basic properties of the WAM model are discussed with special emphasis on the dose-rate dependence in order to demonstrate how the dose-rate dependence, which is built into the model explicitly, plays a key role. Biological effects of long-term exposure to extremely low-dose-rate radiation are discussed in light of analysis of mega-mouse experiments using the WAM model. In the WAM model, the effects of long-term exposure show a saturation property, thus making it distinctly different from the 'linear no threshold (LNT)' hypothesis that predicts a linear increase of the effects with time.