Key result
External γ-ray exposure linked to ~10% higher IHD incidence per Gray, alongside internal alpha-radiation.
Why the study?
Does exposure to external γ-rays and internal alpha radiation increase the incidence and mortality of ischaemic heart disease in Mayak workers?
Cohort (n=22,377)
Does exposure to external γ-rays and internal alpha radiation increase the incidence and mortality of ischaemic heart disease in Mayak workers?
Exposure to external gamma rays and internal alpha radiation is associated with an increased risk of ischaemic heart disease incidence and mortality among nuclear workers.
Answers are grounded in this paper and cite their sources.
May link external γ-ray dose to higher IHD incidence in workers; leaves open mortality effects and practice implications pending confirmatory studies.
OBJECTIVE: Incidence and mortality from ischaemic heart disease (IHD) was studied in an extended cohort of 22,377 workers first employed at the Mayak Production Association during 1948-82 and followed up to the end of 2008. METHODS: Relative risks and excess relative risks per unit dose (ERR/Gy) were calculated based on the maximum likelihood using Epicure software (Hirosoft International Corporation, Seattle, WA). Dose estimates used in analyses were provided by an updated "Mayak Worker Dosimetry System-2008". RESULTS: A significant increasing linear trend in IHD incidence with total dose from external γ-rays was observed after having adjusted for non-radiation factors and dose from internal radiation {ERR/Gy = 0.10 [95% confidence interval (CI): 0.04 to 0.17]}. The pure quadratic model provided a better fit of the data than did the linear one. No significant association of IHD mortality with total dose from external γ-rays after having adjusted for non-radiation factors and dose from internal alpha radiation was observed in the study cohort [ERR/Gy = 0.06 (95% CI: <0 to 0.15)]. A significant increasing linear trend was observed in IHD mortality with total absorbed dose from internal alpha radiation to the liver after having adjusted for non-radiation factors and dose from external γ-rays in both the whole cohort [ERR/Gy = 0.21 (95% CI: 0.01 to 0.58)] and the subcohort of workers exposed at alpha dose <1.00 Gy [ERR/Gy = 1.08 (95% CI: 0.34 to 2.15)]. No association of IHD incidence with total dose from internal alpha radiation to the liver was found in the whole cohort after having adjusted for non-radiation factors and external gamma dose [ERR/Gy = 0.02 (95% CI: not available to 0.10)]. Statistically significant dose effect was revealed in the subcohort of workers exposed to internal alpha radiation at dose to the liver <1.00 Gy [ERR/Gy = 0.44 (95% CI: 0.09 to 0.85)]. CONCLUSION: This study provides strong evidence of IHD incidence and mortality association with external γ-ray exposure and some evidence of IHD incidence and mortality association with internal alpha-radiation exposure. ADVANCES IN KNOWLEDGE: It is the first time the validity of internal radiation dose estimates has been shown to affect the risk of IHD incidence.
No takes yet. Share an insight, caveat, or question.
Azizova et al. (2015) conducted a cohort in Ischaemic heart disease (IHD) (n=22,377). External γ-ray and internal alpha-radiation exposure vs. Unexposed or lower dose reference was evaluated on IHD incidence (ERR/Gy 0.10, 95% CI 0.04 to 0.17). External γ-ray exposure was significantly associated with an increased incidence of ischaemic heart disease (ERR/Gy 0.10; 95% CI 0.04-0.17), alongside associations with internal alpha-radiation.
Synapse has enriched 10 related papers. Consider them for comparative context: