title: Ischaemic heart disease incidence and mortality in an extended cohort of Mayak workers first employed in 1948-1982.
abstract: 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)].
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  It is the first time the validity of internal radiation dose estimates has been shown to affect the risk of IHD incidence.
authors.affiliation: 1 Clinical Department, Southern Urals Biophysics Institute, Ozyorsk, Russia.
authors.forename: Tamara V
authors.initials: TV
authors.lastname: Azizova
authors.affiliation: 1 Clinical Department, Southern Urals Biophysics Institute, Ozyorsk, Russia.
authors.forename: Evgeniya S
authors.initials: ES
authors.lastname: Grigoryeva
authors.affiliation: 2 Epidemiology Department, Public Health England, Didcot, UK.
authors.forename: Richard G E
authors.initials: RG
authors.lastname: Haylock
authors.affiliation: 1 Clinical Department, Southern Urals Biophysics Institute, Ozyorsk, Russia.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Pikulina
authors.affiliation: 1 Clinical Department, Southern Urals Biophysics Institute, Ozyorsk, Russia.
authors.forename: Maria B
authors.initials: MB
authors.lastname: Moseeva
mesh_terms: D000368:Aged; D015984:Causality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000453:epidemiology*; D055848:Nuclear Power Plants; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D011832:Radiation Injuries / Q000453:epidemiology*; D012307:Risk Factors; D012426:Russia