Update #006 - Issued on: June 13, 1995

U.S., Ukraine to Study Childhood Thyroid Cancer From Chernoybl Nuclear Accident

The work will focus on the incidence of thyroid disease, especially cancer, resulting from the 1986 accident at the Chernobyl nuclear power plant. The scientific protocol, signed May 10, 1995 by the U.S. Ambassador to Ukraine and acting Ukrainian Minister of Health, lays out a plan for medically following a group of approximately 70,000 children who lived in areas of Ukraine that were heavily contaminated as a result of the accident.

The primary objective of the study is to determine the extent to which exposure to radioiodine, especially I-131, released in the accident, results in thyroid disease in children. The release of radioiodine is likely to figure prominently in any nuclear power plant disaster and knowledge of its carcinogenic potency is inadequate, especially in children. The new research studies of the Chernobyl accident provide a unique opportunity to understand and quantify the thyroid cancer risk of exposure to radioiodine and the role of potential cofactors, especially dietary idodine deficiency.

The Ukraine study will provide the children exposed to fallout from the Chernobyl accident with a high level of thyroid disease surveillance. Data from the study are also expected to help fill a major gap in the scientific community's knowledge of radiation effects and provide important guidance for development of radiation protection and public health policies.

Under the protocol, a well-defined population of Ukrainian children, aged 0-18 or in utero at the time of the accident, will be examined by well-trained specialists for thyroid disease at least every two years. The 70,000 children had their thyroids measured for radioactivity during the first few weeks following the accident.

Specific objectives of the long-term study are to

• determine the dose- and time-related morphologic and functional changes in the thyroid glands of children exposed to radiation;
• estimate the risk of nodules and cancer as a function of dose in relation to both sex and age;
• compare the relative effectiveness of radioiodine, especially I-131, with that of x-ray and gamma radiation in inducing thyroid nodules and cancer; and
• estimate risk of hypothyroidism as a function of dose in relation to both sex and age

Under the cooperative arrangement, Ukraine will provide medical, scientific, technical and support personnel along with facilities and space for the study, including visiting U.S. scientific and medical personnel. The DOE will provide equipment and supplies, relevant medical, scientific and technical consultation and training for Ukrainian personnel, as appropriate. The study is expected to continue for 15 years.

A similar study of thyroid disease among children is underway in the Republic of Belarus, which also received extensive fallout from the accident. Health effects among Ukrainian workers who were exposed to radiation during the Chernobyl plant cleanup also are to be investigated, specifically for the incidence of leukemia and cataracts. These studies originated under the auspices of a 1988 memorandum of cooperation between the United States and the former Soviet Union concerning civilian nuclear reactor safety following the Chernobyl accident. New formal arrangements were established with the three independent nations (Ukraine, Belarus, and Russia) following the dissolution of the U.S.S.R.

The studies are primarily being carried out for the U.S. by the National Cancer Institute with funding from the Department of Energy and the Nuclear Regulatory Commission. Also participating is Lawrence Livermore National Laboratory. On the Ukraine side, the studies are being carried out by the Ministry of Health of Ukraine, the Ukraine Academy of Medical Sciences, the Ukrainian Research Institute of Endocrinology and Metabolism, the Ukrainian Scientific Center for Radiation Medicine, and the Ukraine Radiation Protection Institute. When fully operational, U.S. - Ukrainian work under the protocol is expected to be funded at about $1 million per year.

DOE Environment, Safety and Health Updates are issued periodically to DOE stakeholders with an interest in protecting the environment and worker health and safety at DOE sites across the nation.

For additional information on this ES&H Update, contact:

Edward Washburn, Program Manager
DOE Office of Environment, Safety & Health
301/903-7030

Mary Jo Zacchero, Communications Director
DOE Office of Environment, Safety & Health
202/586-6993