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ObjectiveTo systematically review and perform a meta-analysis of radiation associated risks of cardiovascular disease in all groups exposed to radiation with individual radiation dose estimates.DesignSystematic review and meta-analysis.Main outcome measuresExcess relative risk per unit dose (Gy), estimated by restricted maximum likelihood methods.Data sourcesPubMed and Medline, Embase, Scopus, Web of Science Core collection databases.Eligibility criteria for selecting studiesDatabases were searched on 6 October 2022, with no limits on date of publication or language. Animal studies and studies without an abstract were excluded.ResultsThe meta-analysis yielded 93 relevant studies. Relative risk per Gy increased for all cardiovascular disease (excess relative risk per Gy of 0.11 (95% confidence interval 0.08 to 0.14)) and for the four major subtypes of cardiovascular disease (ischaemic heart disease, other heart disease, cerebrovascular disease, all other cardiovascular disease). However, interstudy heterogeneity was noted (P<0.05 for all endpoints except for other heart disease), possibly resulting from interstudy variation in unmeasured confounders or effect modifiers, which is markedly reduced if attention is restricted to higher quality studies or those at moderate doses (<0.5 Gy) or low dose rates (<5 mGy/h). For ischaemic heart disease and all cardiovascular disease, risks were larger per unit dose for lower dose (inverse dose effect) and for fractionated exposures (inverse dose fractionation effect). Population based excess absolute risks are estimated for a number of national populations (Canada, England and Wales, France, Germany, Japan, USA) and range from 2.33% per Gy (95% confidence interval 1.69% to 2.98%) for England and Wales to 3.66% per Gy (2.65% to 4.68%) for Germany, largely reflecting the underlying rates of cardiovascular disease mortality in these populations. Estimated risk of mortality from cardiovascular disease are generally dominated by cerebrovascular disease (around 0.94-1.26% per Gy), with the next largest contribution from ischaemic heart disease (around 0.30-1.20% per Gy).ConclusionsResults provide evidence supporting a causal association between radiation exposure and cardiovascular disease at high dose, and to a lesser extent at low dose, with some indications of differences in risk between acute and chronic exposures, which require further investigation. The observed heterogeneity complicates a causal interpretation of these findings, although this heterogeneity is much reduced if only higher quality studies or those at moderate doses or low dose rates are considered. Studies are needed to assess in more detail modifications of radiation effect by lifestyle and medical risk factors.Systematic review registrationPROSPERO CRD42020202036

This paper presents results of the analysis of mortality among Chernobyl accident emergency workers who are resident in Russia. The analysis is based on information for the cohort of emergency workers (males) from six regions of Russia including 65,905 persons with documented external doses in the range 0.005-03 Sv. These data were gathered during the period 1991 to 1998 and cover a total of 426,304 follow-up person-y. In this period, 4,995 deaths occurred in the cohort under study. The mortality analysis was performed for four groups of causes of death (ICD-9 codes): (1) malignant neoplasms (140-239); (2) cardiovascular diseases (390-459); (3) injuries, poisoning and violent deaths, (800-999); and (4) the remainder (other than the above). The standardized mortality rate for groups 1, 3, and 4 is less than unity and varies from 0.6 to 0.9. For group 2 (death from cardiovascular diseases) the standardized mortality rate conforms with the control within 95% confidence intervals. The control was the mortality rate (males) for the corresponding ages in Russia in general and the internal control, the spontaneous mortality among emergency workers, derived from the equation of the observed and expected number of cases in the followed up cohort. Dose response of mortality was studied. Statistically significant radiation risks were obtained for mortality from malignant neoplasms (515 cases) and cardiovascular diseases (1,728 cases). The values of the excess relative risk per unit dose (ERR Sv(-1)) for malignant neoplasms and cardiovascular diseases are estimated as 2.11 (1.31, 2.92 95% CI) and 0.54 (0.18,0.91 95% CI) (for external control), 2.04 (0.45, 4.31 95% CI) and 0.79 (0.07, 1.64 95% CI) (for internal control), respectively. The risk of death from all noncancer causes is close to zero and not statistically significant.

This paper presents an analysis of data of the Russian National Medical and Dosimetric Registry on the incidence of leukaemia among 155 680 male Chernobyl accident emergency workers (EWs) who were resident in the Russian Federation (RF) for the period from 1986 to the end of 1993. The system of collection and verification of data on leukaemia is described. 48 cases of leukaemia among EWs were identified in 1986 - 1993. The principal analysis includes 34 leukaemia cases occurring more than two years after first exposure. The analysis was carried out for all leukaemia and leukaemia excluding chronic lymphocytic leukaemia (CLL), separately. Distributions of leukaemia cases by age, time of diagnosis since entry into the Chernobyl zone, radiation dose, date of entry into the Chernobyl zone, duration of stay in the region of Chernobyl were calculated. To evaluate leukaemia risks associated with various factors the case - control methodology was used. Radiation dose, date of entry into the zone, duration of stay in the zone were used as risk factors. No significant associations between leukaemia risks and the investigated factors were found. Calculation of the standardised registration ratios (SRR) revealed a significant increase in the registration of leukaemia among all EWs (SRR = 205, 95% confidence interval (CI) 136 - 297) and the EWs arriving in the zone during 1986 - 1987 (SRR = 200, 95% CI: 127 - 300) compared with the general male population of the RF in 1991 - 1993. However, raised SRRs may be accounted for by the differences in medical screening in the compared populations, particularly the efforts made to identify leukaemia cases among the EWs. The absence of a dose-related trend for leukaemia indicates that this explanation is likely to be correct.