Thyroid Abnormalities Associated With Exposure to Atmospheric Emissions of Radioactive Iodine

Study Summary

Background: * An inadequate filtering system at the Mayak nuclear weapons production facility in Ozyorsk, Russia, allowed the release of various radioactive materials, particularly I-131 (radioactive iodine) into the city's atmosphere during the 1950s. * A recent pilot study found a higher prevalence of thyroid nodules in Ozyorsk residents who were exposed to the radiation in childhood during years of heavy atmospheric emissions (1952-1953) than in children exposed in later years (between 1967 and 1991) when there were almost no radioactive releases. * Understanding the role of I-131 in the development of thyroid disease is important because I-131 is commonly used in medicine (e.g., to treat hyperthyroidism and thyroid cancer and to diagnose thyroid disease), and it is the major source of thyroid gland exposure in fallout from atomic bomb explosions, nuclear power plant accidents, and atmospheric venting from plutonium manufacturing facilities. Objectives: -To expand the pilot study to include 350 Ozyorsk residents who were exposed in childhood to moderate levels of radiation in order to evaluate thyroid disease in relation to the dose of I-131 exposure. Eligibility: -People who were born and living in Ozyorsk, Russia between 1954 and 1955, the period of mild radioactive releases from the Mayak nuclear weapons plant. Design: * Participants' thyroid gland and structure are examined with an ultrasound examination and blood tests. * Participants with a possible thyroid gland disorder are referred to specialists for additional diagnostic procedures.