Cataracts among Chernobyl clean-up workers: implications regarding permissible eye exposures

Radiat Res. 2007 Feb;167(2):233-43. doi: 10.1667/rr0298.1.


The eyes of a prospective cohort of 8,607 Chernobyl clean-up workers (liquidators) were assessed for cataract at 12 and 14 years after exposure. The prevalence of strictly age-related cataracts was low, as expected (only 3.9% had nuclear cataracts at either examination), since 90% of the cohort was younger than 55 years of age at first examination. However, posterior subcapsular or cortical cataracts characteristic of radiation exposure were present in 25% of the subjects. The data for Stage 1 cataracts, and specifically for posterior subcapsular cataracts, revealed a significant dose response. When various cataract end points were analyzed for dose thresholds, the confidence intervals all excluded values greater than 700 mGy. Linear-quadratic dose-response models yielded mostly linear associations, with weak evidence of upward curvature. The findings do not support the ICRP 60 risk guideline assumption of a 5-Gy threshold for "detectable opacities" from protracted exposures but rather point to a dose-effect threshold of under 1 Gy. Thus, given that cataract is the dose-limiting ocular pathology in current eye risk guidelines, revision of the allowable exposure of the human visual system to ionizing radiation should be considered.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Cataract / etiology*
  • Chernobyl Nuclear Accident*
  • Cohort Studies
  • Dose-Response Relationship, Radiation
  • Eye Injuries / etiology*
  • Female
  • Humans
  • Lens Capsule, Crystalline / radiation effects*
  • Lens Cortex, Crystalline / radiation effects*
  • Male
  • Middle Aged
  • Nuclear Reactors
  • Radiation, Ionizing
  • Risk