U.S.–Russia Agreement Continues Radiation Effects Research

by Ethel S. Gilbert, Ph.D., and Sara Schonfeld, Ph.D., Radiation Epidemiology Branch

In July, U.S. Secretary of State Hillary Clinton and Russian Foreign Minister Sergey Lavrov formally extended the Joint Coordinating Committee for Radiation Effects Research agreement, the legal basis for U.S. and Russian Federation scientists to conduct and coordinate scientific research on the health effects of radiation exposure at former Russian nuclear weapons production sites. These sites include the Mayak nuclear facility in the Southern Urals, which began operation in 1948 and produced plutonium for the former Soviet Union's weapons program. Scientists from DCEG's Radiation Epidemiology Branch (REB) are collaborating with Russian scientists to study individuals exposed as a result of Mayak operations. Workers at that facility were exposed to plutonium and to protracted external radiation at much higher doses than nuclear workers in other countries. Offspring of these workers were potentially exposed in utero, and people who resided along the Techa River were exposed to radioactive waste that was discharged into the river.

Using radiation dose information from the U.S. Department of Energy under the Russian Health Studies Program, REB investigators and their collaborators have evaluated dose-response relationships for radiation-related cancer in these populations. For workers, strong dose-response relationships have been demonstrated between plutonium exposure and cancers of the lung, liver, and bone (the three major sites of plutonium deposition), while external dose-response relationships have been observed for mortality from solid cancer and leukemia. For the Techa River cohort, dose-response relationships have been noted for solid cancer and leukemia using both mortality and incidence data.

Analyses based on updated follow-up information and improved dose estimates are in progress. These studies are providing unique information on the risk of cancer from protracted radiation exposure that is important for establishing international recommendations on radiation protection.