Chornobyl Health Effects Studies

The Chornobyl Health Effects Studies were originally established on April 26, 1988 through a bilateral agreement between the United States and the former Soviet Union to study the health consequences of the Chornobyl accident, which occurred on April 26, 1986. After the dissolution of the Soviet Union, the United States signed separate agreements with Belarus and Ukraine to continue these projects.

The explosion at the Chornobyl Nuclear Power Plant in northern Ukraine is considered to be the worst nuclear accident in that 50 tons of radioactive dust were dispersed over 140,000 square miles of Belarus, Ukraine, and Russia, and 4.9 million people were estimated to have been exposed to radiation. In addition to the general population, 600,000 to 800,000 Ukrainian clean-up workers, referred to as "liquidators", were exposed. These workers took part in abating the radioactive contamination at the site.

Currently, DOE is co-funding several studies jointly with the National Cancer Institute (NCI). All studies are conducted by scientists at NCI and Columbia University, jointly with investigators from Ukraine and Belarus:

Study of Thyroid Cancer and other Thyroid Diseases: The primary objective of this collaborative research is to determine the relationship between 131I exposure from the Chornobyl accident and risk of thyroid cancer. The effect of dose level, age at the time of exposure and gender are of particular interest. Associations between 131I and benign thyroid nodules and other thyroid diseases will also be evaluated. The effect of 131I in inducing thyroid cancer will be compared with published data on clinical therapeutic exposure to x-ray and gamma irradiation to assess their relative potency. Study participants include 12,000 Belarusian and 12,000 Ukrainians who were under the age of 18 years at the time of the Chornobyl accident. All study participants had their thyroid glands measured for radioactivity following the accident.

This study has two arms:

• Belarus Thyroid Study, the Belarus arm, and
• Ukraine Thyroid Study, the Ukrainian arm.

Ukraine In Utero Thyroid Study: a sub study in Ukrainian children who were exposed in utero at the time of the Chornobyl accident.

Study of Leukemia and Other Hematological Diseases Among Liquidators in Ukraine: This a case-control study of Leukemia and other Related Disorders in Ukrainian clean-up workers. Subjects are approximately 110,000 liquidators in the Ukrainian State Chornobyl Registry who first worked in the 30 km Chornobyl exclusion zone between April 26, 1986 and December 31, 1991, and who were resident at the time of registration in Kiev or one of five Ukrainian Oblasts. .For each case five controls from the same group of liquidators matched for age and area of residence are drawn.

More information on the Chornobyl studies could be obtained by visiting the following website maintained by the Division of Cancer Epidemiology and Genetics, National Cancer Institute:

http://www.dceg.cancer.gov/radia-researchIonizingRadiation.html#Chornobyl

Program Manager: Mohandas Bhat