A cohort study of thyroid disease in relation to fallout from nuclear weapons testing

JAMA. 1993 Nov 3;270(17):2076-82.


Objective: To estimate individual radiation doses and current thyroid disease status for a previously identified cohort of 4818 schoolchildren potentially exposed to fallout from detonations of nuclear devices at the Nevada Test Site between 1951 and 1958.

Design: Cohort analytic study.

Setting: Communities in southwestern Utah, southeastern Nevada, and southeastern Arizona.

Participants: Individuals who were still residing in the three-state area (n = 3122) were reexamined in 1985 and 1986, and information on the subjects' and their mothers' milk and vegetable consumption during the fallout period was obtained by telephone interview (n = 3545). After exclusions to eliminate missing data and confounding factors, 2473 subjects were available for analysis.

Main outcome measures: Individual radiation doses to the thyroid were estimated by combining consumption data with radionuclide deposition rates provided by the US Department of Energy and a survey of milk producers. Relative risk models adjusted for age, sex, and state were fitted using maximum likelihood to period prevalence data for thyroid carcinomas, neoplasms, and nodules.

Results: Doses ranged from 0 mGy to 4600 mGy, and averaged 170 mGy in Utah. There was a statistically significant excess of thyroid neoplasms (benign and malignant; n = 19), with an increase in excess relative risk of 0.7% per milligray. A relative risk for thyroid neoplasms of 3.4 was observed among 169 subjects exposed to doses greater than 400 mGy. Positive but nonsignificant dose-response slopes were found for carcinomas and nodules.

Conclusions: Exposure to Nevada Test Site-generated radioiodines was associated with an excess of thyroid neoplasms. The conclusions are limited by the small number of exposed individuals and the low incidence of thyroid neoplasms.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Arizona / epidemiology
  • Bias
  • Child
  • Cohort Studies
  • Environmental Exposure / adverse effects*
  • Environmental Exposure / statistics & numerical data
  • Female
  • Humans
  • Iodine Radioisotopes / adverse effects
  • Likelihood Functions
  • Longitudinal Studies
  • Male
  • Nevada / epidemiology
  • Nuclear Warfare*
  • Odds Ratio
  • Radiation Dosage
  • Radioactive Fallout / adverse effects*
  • Radioactive Fallout / statistics & numerical data
  • Radiometry
  • Risk Factors
  • Thyroid Diseases / epidemiology*
  • Thyroid Diseases / etiology
  • Utah / epidemiology


  • Iodine Radioisotopes
  • Radioactive Fallout