Chernobyl health effects may never be seen.

Chernobyl health effects may never be seen

Radioactive fallout from the 1986 Chernobyl accident poses virtually no lingering threat to most people in the world, a team of U.S. scientists contends. In what they call the first scientific study to estimate Chernobyl's effects on human health worldwide, the researchers say that only people within about 30 kilometers of the Soviet nuclear power plant might develop fatal cancers possibly attributable to the accident.

But even for the 115,000 people evacuated from that zone, the effects of the event may never be quantified, says Marvin Goldman of the University of California, Davis. In the Dec. 16 SCIENCE, Goldman, Lynn R. Anspaugh of Lawrence Livermore (Calif.) National Laboratory and Robert J. Catlin of the Electric Power Research Institute in Palo Alto, Calif., say epidemiologic studies may never detect any health effects of the Chernobyl accident because the radiation released will increase everyday "background" risks almost negligibly.

The risk of fatal cancers -- now considered about 15 percent for any individual -- may increase about 0.02 percent for the Soviet population, including people who lived near Chernobyl or worked there, the authors estimate. For non-Soviet Europeans, the risk may rise 0.01 percent, and for the Northern Hemisphere population in general, the risk may increased 0.0003 percent, the scientists report.

"These are probably reasonable estimates and the best anybody can come up with at the current time," Charles W. Miller of the Illinois Department of Nuclear Safety, in Springfield, told SCIENCE NEWS. The authors themselves say the estimates may be too high and the possibility of a zero increase should not be ruled out for people beyond the 30-km zone.

Although several dozen people died shortly after short-term, close-up exposure to the Chernobyl radiation, most people near the reactor absorbed radiation gradually. The researchers consider this kind of prolonged exposure less hazardous than instantaneous abosrption of a specific dose.

"Our only hope of seeing any health effects will be a follow-up study of myeloid leukemia in the 30-km population," Goldman says. Myeloid leukemia -- a fatal disease afflicting some residents of Hiroshima and Nagasaki less than 10 years after atomic explosions devastated those cities in 1945 -- has such a low background occurrence rate that even a very slight increase in cases might be detected, he says.