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. Last Updated: 07/27/2016

U.S. Trades Sensor for Russian Radiation Records

DENVER, Colorado -- U.S. scientists say an unusual trade between Russia and a defunct Colorado nuclear weapons plant will provide a better understanding of the risks of radiation exposure.

Russia has agreed to give American scientists the medical records of thousands of nuclear plant workers exposed to daily doses of radiation nearly a half-century ago.

In exchange, the former Rocky Flats nuclear plant near Denver is sending Russia a device that measures plutonium levels in people.

The Russian records are the first major compilation of data on people exposed to sustained radiation, scientists say. Doctors worldwide have been studying the issue for years to determine safe levels of exposure to everything from medical X-rays to nuclear waste sites.

"It's a scientific bonanza,'' said Dr. Marvin Goldman, professor of radiological sciences at the University of California-Davis, who has worked closely with Russian scientists for nearly a decade and proposed that Rocky Flats donate the detector to help a joint effort between the two countries.

While the threat of a nuclear attack diminished with the end of the Cold War, determining safe radiation levels remains important as nuclear weapons are dismantled and nuclear waste is stored.

"How low do you regulate? What are safe levels? The answers are still a moving target, but this will enhance what we have,'' said Dr. Daniel Hoffman, chairman of epidemiology at George Washington University School of Public Health, who has also traveled to Russia to study effects of radiation.

Russian scientists are sharing case histories of more than 10,000 people who worked at the Mayak plutonium-producing facility between 1948 and 1953, when the former Soviet Union was locked in an arms race with the United States.

Mayak was Russia's largest and oldest weapons production site, and its workers didn't wear protective masks or hoods, Goldman said.

The records are expected to include tissue samples and autopsy results and reveal what kind of cancer workers got, the radiation levels that caused the disease and the path radiation took upon entering the body, Goldman said. More than half the workers are still alive.

Similar studies were not possible in the United States because American nuclear plant workers were subjected to lower doses of radiation.

Government regulations prohibited American nuclear plant workers from being exposed to more than 12 rems -- a unit of measure -- of radiation per year before 1957. Regulations were tightened that year so workers could be exposed to no more than five rems per year, but most workers were exposed to an average of one a year, Goldman said.

Their Russian counterparts received as much as 100 rems per year in the 1940s and early '50s, he said.

Today, the average person in the United States is exposed to about one rem every three years from natural and manmade sources.

The swap comes from a 1994 agreement between the United States and Russia to coordinate research on the health effects of radiation.