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

The International Commission on Radiological Protection (ICRP) has considered for over 60 years that the lens of the eye is among the most radiosensitive tissues, and has recommended dose limits for the lens to prevent occurrence of vision impairing cataracts (VICs). Epidemiological evidence that doses much lower than previously thought produce cataracts led ICRP to recommend reducing dose threshold for VICs and reducing an occupational equivalent dose limit for the lens in 2011, when only a single threshold of 0.5 Gy was recommended. On the basis of epidemiological evidence, ICRP assumed progression of minor opacities into VICs and no dose rate effect. This contrasts with previously recommended separate thresholds for minor opacities and VICs, and for different exposure scenarios. Progression was assumed based on similar risks of cataracts and cataract surgery in Japanese atomic bomb survivors. The absence of dose rate effect derived from the observed similar thresholds for protracted exposures in Chernobyl cleanup workers and in atomic bomb survivors. Since 2011, there has been an increasing body of epidemiological evidence relating to cataracts and other ocular diseases (i.e. glaucoma and macular degeneration), particularly at low doses and low dose rates. This review paper gives an overview of the scientific basis of the 2011 ICRP recommendation, discusses the plausibility of these two assumptions in the light of emerging scientific evidence, and considers the radiosensitivity of the lens among ocular structures.

In this study the incidence risk of lower extremity arterial disease (LEAD; international classification of diseases version 9 code 440.2) was assessed in a cohort of workers occupationally exposed to radiation over a prolonged period. The study cohort includes 22,377 workers of the Mayak Production Association (25% of whom are females) first employed at one of the main facilities in 1948-1982 and followed up to the end of 2008. Dose estimates used in the study are provided by Mayak Worker Dosimetry System 2008. The mean total dose from external gamma-rays is 0.54 Gy for males and 0.44 Gy for females. The mean absorbed liver dose from internal alpha-radiation due to incorporated plutonium is 0.23 Gy in males and 0.44 Gy in females. Relative risks and excess relative risks per unit dose (ERR/Gy) are calculated based on maximum likelihood. A total of 943 cases of LEAD are registered in the study cohort during the follow-up of 512,801 person-years. A significant association of LEAD incidence with total dose from external gamma-rays (based on a linear model) was revealed, and the ERR/Gy is 0.27 (95% confidence interval (CI) 0.11; 0.48). It turned out that a linear-exponential model provides a better fit of the data (∆AIC = 9.957). Inclusion of an adjustment for internal alpha-radiation dose resulted in the reduction of the ERR/Gy to 0.19 (95% CI 0.05; 0.39), but the risk remains significant. No association of LEAD incidence with dose from internal alpha-radiation was found in the study worker cohort. It is concluded that this study provides evidence for an association of LEAD incidence with dose from external gamma-rays taking non-radiation factors into account.

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Purpose: To assess cataract type specific risks in a cohort of workers occupationally exposed to ionizing radiation over prolonged periods. Material and methods: The present retrospective cohort study included 22,377 workers first employed at a nuclear production facility in 1948–1982 and followed up till the end of 2008. By the end of the follow-up period in the study worker cohort 3123 cases of cortical cataract, 1239 cases of posterior subcapsular cataract (PSC) and 2033 cases of nuclear cataracts were registered over 486,245, 489,162, 492,004 person-years of follow-up, respectively. Results: The incidence of PSC, cortical and nuclear cataracts was significantly linearly associated with the cumulative radiation dose. The excess relative risk per unit dose of external gamma-ray exposure (ERR/Sv) was 0.91 (95 % CI: 0.67–1.20) for PSC, 0.63 (95 % CI: 0.49–0.76) for cortical cataracts and 0.47 (95 % CI: 0.35–0.60) for nuclear cataracts. Exclusion of an adjustment for neutron dose and inclusion of additional adjustments for body mass index and smoking index reduced ERRs/Sv for all types of cataracts. However, an additional adjustment for glaucoma increased the incidence risks of cortical and nuclear cataracts just modestly (but not for PSC). Inclusion of an adjustment for diabetes mellitus reduced the ERR/Sv of external gamma-ray exposure only for PSC incidence. Increased incidence risks of all cataract types were observed in both males and females of the study cohort, but ERR/Sv was significantly higher in females (p < 0.001), especially for PSC. Conclusion: The incidence of various types of cataracts in the cohort of workers occupationally chronically exposed to ionizing radiation was associated with the cumulative dose of external gamma-ray exposure.