The detriment-adjusted nominal risk coefficients recommended by ICRP have been based, to a large extent, on data obtained from the atomic bomb survivors in Japan. ICRP introduced a Dose and Dose-Rate Effectiveness Factor (DDREF) of 2 to include in calculations of these risk coefficients for application at the low doses and low-dose rate exposures typical in radiological protection. The DDREF was included to account for the survivors’ single acute exposure, and because a linear quadratic instead of a linear risk to dose response was thought to be the most plausible biological model.
This paper summarizes the recent work of ICRP Task Group 91 on this topic. Task Group activities have included reviews of the history of low-dose and low-dose-rate effects, various exposure scenarios and their doses and dose rates, radiation-induced effects at the molecular, cellular, animal, and human level, and biologically-based mechanistic models of carcinogenesis. The Task Group performed a meta-analysis of low-dose-rate epidemiological studies, and re-analyses of published results on radiation-induced effects among animal models and among Japanese atomic bomb survivors.
Keywords: radiation-induced biological effects; low-dose effects; low-dose-rate effects
Thanks for this question. In fact we left all of the studies out one-by-one. This exercise was done to understand the uncertainties behind the meta analysis; it also demonstrates that if just one study dominates, then one must be a bit more careful in interpreting the overall result.
is that ok that one leaves a group out, when this group dominates the result?