title: Hyperparathyroidism in persons exposed to iodine-131 from the Hanford Nuclear Site.
abstract: BACKGROUND
  The risk of primary hyperparathyroidism from exposure to external radiation has been well documented in the last 20 yr. However, it remains unclear whether hyperparathyroidism might also be caused by internal exposure to radioactive iodine.
  
  
  OBJECTIVE
  The objective of this study was to determine whether exposure to 131I from the Hanford Nuclear Site during 1944-1957 increased the risk of hyperparathyroidism among people living in the area.
  
  
  METHODS
  The Hanford Thyroid Disease Study was conducted as a retrospective cohort study.
  
  
  METHODS
  The study setting was the general community in Washington State.
  
  
  METHODS
  The participants were 5199 persons born to mothers with usual residence in one of seven counties in eastern Washington State, randomly selected from birth records for the years 1940-1946.
  
  
  METHODS
  Of the 5199 selected, 3440 underwent a Hanford Thyroid Disease Study clinical evaluation, including an evaluation for hyperparathyroidism. Individual thyroid radiation dose, which could be estimated for 3191 study participants, ranged from 0.0029-2823 mGy (mean, 174 mGy).
  
  
  METHODS
  Hyperparathyroidism was the main outcome measure.
  
  
  RESULTS
  Of 3440 evaluable participants, we confirmed 12 cases of primary hyperparathyroidism (0.35%). We found no evidence that the cumulative incidence of hyperparathyroidism increased with increasing radiation dose.
  
  
  CONCLUSIONS
  In summary, this study shows no evidence that 131I, received at young ages and at the doses and exposure conditions experienced by this cohort, increased the risk of primary hyperparathyroidism. However, the effects of different doses and conditions of exposure to 131I on the risk of hyperparathyroidism remain to be defined.
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98195, USA. tehamilton@aol.com
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Hamilton
authors.forename: Scott
authors.initials: S
authors.lastname: Davis
authors.forename: Lynn
authors.initials: L
authors.lastname: Onstad
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Kopecky
mesh_terms: D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D004781:Environmental Exposure; D006801:Humans; D006961:Hyperparathyroidism / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D007457:Iodine Radioisotopes / Q000009:adverse effects*; D008875:Middle Aged; D012189:Retrospective Studies; D014861:Washington / Q000453:epidemiology
chemical_list: D007457:Iodine Radioisotopes