Excess Relative Risk of Mortality from Diseases of the Circulation System after Irradiation. Report 1. Overview of Reviews and Meta-analysis Declared Effects of Low Doses

Abstract

A review of two reports is devoted to the problem of the significance of excess relative risks (ERR) per 1 Gy/Sv for mortality from diseases of the circulatory system for various exposed groups from the standpoint of epidemiology and in terms of the effects of low doses of radiation. Report 1 provides an overview of reviews and meta-analyses, together with key studies, on this topic. In most sources, 2005–2021 (publications by M.P. Little with co-workers, and others) reveals an ideological bias towards the effects of low doses of radiation (noted in the titles or summaries of almost all papers), and often there was a lack of understanding about the upper limit of this range accepted by international organizations for low LET radiation (up to 0.1 Gy according to UNSCEAR, ICRP, BEIR, etc.). In selected M.P. Little and co-authors sources for reviews and meta-analyses observed both absurd ERR values per 1 Gy and incorrect recalculations of the risk estimated in the originals at 0.1 Gy. Examples of the incorrectness of such estimations are presented, since ERR per 1 Gy calculated for ranges of lower doses may differ from those for high dose ranges by many times, and this is a systemic phenomenon, despite all the declarations of a linear non-threshold concept. Selection of sources for meta-analyses used by M.P. Little and other authors (2010–2020) violates the principles of homogeneity (groups with radiotherapy (including children with tinea capitis) are combined with miners, liquidators of the Chernobyl accident, etc.), representing an illustration of a meme of critics of meta-analytical approaches (“combination of apples and oranges”). The values of ERR per 1 Gy obtained as a result of meta-analyses for diseases of the circulatory system in general and for their individual types according to epidemiological risk scales (R.R. Monson scale, 1980; 1990) are either insignificant (ERR = 0–0.2), or, rarely, located on the border of weak associations (ERR = 0.2–0.5). An analysis of data from reviews and meta-analyses on the topic did not reveal sources that investigated effects limited to low dose ranges. In almost all cases, with some exceptions (miners with radon exposure, cohorts with absurd risks, etc.), the upper limit of the range for groups in the samples was either medium (0.1–1 Gy) or high (1 Gy). ) doses. An analysis of almost all publications on the topic of Mayak employees (T.V. Azizova with co-workers; 2010–2018; 31 sources) showed a lack of risk studies for groups with low doses of external exposure (up to 0.1 Gy), with the exception of works from 2014 and 2018, in which either reverse or weak effects were established in the absence of dose dependence. Thus, no samples in reviews and meta-analyses, as well as data for Mayak PA, provide material on the correspon-ding effect of low doses, despite the prevailing general idea of its “proof”. It was concluded that one should adhere to the statement of international organizations (USCEAR, ICRP, NCRP, BEIR, etc.) that the threshold for increasing mortality from diseases of the circulatory system is not less than 0.5 Gy, and then raise the issue of their radiation attribution for low doses impractical.