Thyroid Abnormalities Associated With Exposure to Atmospheric Emissions of Radioactive Iodine

April 4, 2018 updated by: National Cancer Institute (NCI)

Thyroid Abnormalities Associated With Protracted Childhood I-131 Exposure From Atmospheric Emissions From the Mayak Nuclear Plant in Russia

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.

Study Overview

Status

Terminated

Detailed Description

We plan to expand a completed pilot study that evaluated the prevalence of thyroid abnormalities in relation to childhood exposure to atmospheric emissions of radioactive iodines from the Mayak Nuclear Weapons Plant in Ozyorsk, Russia. The pilot study population was composed of a defined cohort of approximately 900 Ozyorsk residents who were born between January 1, 1952 and December 31, 1953. The exposed population was comprised of persons who lived in Ozyorsk during the years of heavy atmospheric releases (1952-1953). Members of the nonexposed group moved to Ozyorsk between 1967 and 1991, i.e. when there were almost no radioactive releases. Results from the pilot study suggest an elevated prevalence of thyroid nodules in the exposed population. Given the positive results from the pilot study and the US Department of Energy's (DOE) decision to fund a dose reconstruction project for the Ozyorsk population, we intend to expand the study to include an additional 350 people born and living in Ozyorsk between 1954 and 1955, i.e. exposed to moderate levels of radiation .

Methods similar to those used in the pilot study will be used in the expanded study. Members of the study population will be invited to participate in a special thyroid screening protocol when they come for their annual routine medical examination at the Ozyorsk automated dispensary system (ASDOC). The thyroid gland is clinically examined by two ASDOC physicians specifically trained in thyroid palpation. Thyroid abnormalities will be detected based on physical examinations, assessment of TSH levels, and ultrasound imaging. Biochemical laboratory tests, including Free T(4), and anti-thyroperoxidase antibodies will be assayed as necessary. Patients are sent to a consulting endocrinologist if the palpation, ultrasound or laboratory findings suggest a thyroid disorder. Fine needle aspiration (FNA) biopsy is performed when a tumor is suspected. Although the FNA is not be done as part of the study research, but rather as part of the regular Ozyorsk medical system, the results will be given to the study staff to help make diagnostic decisions. Patients with complicated thyroid disease will be referred to an experienced consulting thyroid specialist. Patients with diagnosed thyroid disease are treated within the regular medical system in Ozyorsk.

Study Type

Observational

Enrollment (Actual)

360

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center, 9000 Rockville Pike

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

51 years to 52 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

  • Eligibility Criteria:

Currently living and working in Ozyorsk, Russian Federation

Born and living in Ozyorsk between January 1954 and December 1955

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

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Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 21, 2006

Study Completion

September 3, 2013

Study Registration Dates

First Submitted

June 19, 2006

First Submitted That Met QC Criteria

June 19, 2006

First Posted (Estimate)

June 21, 2006

Study Record Updates

Last Update Posted (Actual)

April 5, 2018

Last Update Submitted That Met QC Criteria

April 4, 2018

Last Verified

September 3, 2013

More Information

Terms related to this study

Other Study ID Numbers

  • 999906103
  • 06-C-N103

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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