Davis had been back from Japan for less than a year when Chernobyl blew. He and Kopecky soon realized the scientific opportunity the disaster presented and the importance of setting up studies there right away. Try as they might, however, they were “pretty much shut down” as Cold War tension between the U.S. and Soviet Union proved insurmountable. “It’s really unfortunate,” says Davis. “If you could get in there at the time and measure radiation, both in the environment and in the people themselves, that’s obviously far better than trying to reconstruct it several years after the fact.”
Ultimately, serendipity opened the door. In 1990, a Russian helicopter pilot involved in the initial efforts to contain the radiation at Chernobyl came to Fred Hutchinson for a bone-marrow transplant. That led to an informal exchange program between the Hutch, led by then-President Robert Day, and the National Center for Hematology in Moscow.
Davis and Kopecky made their first trip to Moscow that year and quickly began laying the groundwork for their research. One year later, however, the Soviet Union collapsed. Many observers believe Chernobyl played a significant role in the breakup due to the government’s lack of candor—it did not even acknowledge the explosion for nearly three days—and the disaster’s enormous drain on the economy: an estimated $235 billion in Belarus alone over a 30-year period.
For Davis, the collapse meant renegotiating with three new governments—Ukraine, where Chernobyl is located, and neighboring Belarus and Russia. Sailing to the rescue was Admiral Elmo Zumwalt. A trustee at Fred Hutchinson and former chief of naval operations for the U.S. Navy, Zumwalt used his connections to help the Hutch establish new relationships with the three countries. With funding from the Office of Naval Research, the groups formed the International Consortium for Health Effects of Radiation.
Political hurdles aren’t the only obstacles that Davis and his colleagues have had to overcome. They’ve also had to go backwards in time, determining radiation exposure levels based on limited data collected by the Soviets immediately after the disaster and on interviews with current survivors.
“The basic idea,” says Davis, “is that you try to assemble as much information as you can about how much radiation was released, what types of radiation were released, and then develop [computer] models to account for how it was dispersed through the air, deposited on the ground, taken up by vegetation into the food chain … and then eventually how consumption of contaminated milk and food and water would translate into radiation doses in an individual.”
One particular type of radiation—a radioactive form of iodine known as iodine-131—is the focal point of the Davis team’s research. Unlike other Chernobyl fallout components such as caesium-137, strontium-90 and plutonium, which remain at alarming levels to this day depending on their relationship to fallout patterns, iodine-131 decays rapidly and no longer poses an active threat. Tragically, though, in the days and weeks following the explosion, concentrated amounts of iodine-131 accumulated in the milk of cows grazing in poisoned pastures. And when people consumed dairy products derived from that milk, their thyroid glands, which absorb iodine, soaked up cancer-causing doses of radiation.
The first sign of iodine-131’s insidious impact came soon after the disaster, when numerous cases of thyroid cancer—which normally occurs only in adults—began showing up among children in the area where the fallout settled. Later, adults who were exposed as children also started developing thyroid cancer in disproportionate numbers. Now, Davis and his team have provided evidence of what many suspected—that Chernobyl spread thyroid cancer—and have generated new information about radiation dosages and risk.
In a world where nuclear power remains an important energy option and where nuclear terrorism is a very real threat, collecting such information is more than an academic exercise. “Unfortunately, I believe it is pretty likely that another incident will occur,” says Davis. “Knowing as much as we can regarding the effects of radiation exposures at different levels and who is likely to be at highest risk will hopefully better prepare us for responding to such an event.”
— Brad Broberg is a free-lance writer based in south King County.