The Truly Wild Life Around Chernobyl
Many animals are in evolutionary overdrive
People from the region are clearly paying a heavy price for the accident as cancer and other disorders related to genetic mutations are rising in those who received the heaviest doses. Last month, scientists reported in the journal Nature that rates of thyroid cancer in Ukrainian children have climbed fivefold overall and 30-fold in those who lived nearest to Chernobyl. Higher rates of spontaneous abortion and birth defects have been documented in Belarus, but it's not clear that radiation exposure is the primary cause, says Martin Cherniack, an associate professor of medicine and international health at Yale University. Researchers also expect at least a small increase in leukemias and other cancers to show up over the years, but that, too, may be hard to trace to the Chernobyl accident.
The human toll triggers a conflict of emotions for Chesser. "The research potential is very exciting, but I also feel the sadness of all the people who were betrayed," he says. The picturesque landscape near Chernobyl will be repopulated in the coming years, but more by genetically adapted plants, insects and field mice than by people.
CHERNOBYL'S ASSAULT ON GENES Scientists now know a great deal about the ways that radiation can cause genetic mutations. 1. Radiation release. In 1986, an accident at a Chernobyl reactor caused the release of tons of radioactive materials. 2. Food consumption. Radioactive cesium and strontium are taken up by plants and once eaten, become incorporated in animals' muscle and bones. 3. Cell death. Radiation bombards DNA inside animal cells, causing chromosomes to break and, usually, cells to die. 4. DNA damage. Radiation can also break apart DNA strands. 5. Gene repair. DNA is often repaired, but inaccurate restoration can lead to gene mutations that are passed on to new generations of cells. 6. Cancer's origin. Some mutations release the brakes that normally control cell division. Cancer may develop. 7. Inherited mutations. Mutations in egg and sperm cells can be passed to the animal's offspring. Sometimes that causes birth defects. Harmful defects can hasten the death of offspring, but some "defects" may benefit an offspring's chance of survival.
CHERNOBYL'S FUTURE What to do with Reactor 4? Two reactors continue to operate at Chernobyl--one in a building just next to the shoddily housed remains of the 1986 explosion. Because of Ukraine's entrenched nuclear bureaucracy and a desperate need for energy and employment, the new nation has resisted closing the Chernobyl station in spite of experts' fears of another nuclear accident.
In April, after years of pressure from abroad and from environmentalists at home, Ukraine's President Leonid Kuchma announced that he is committed to shutting down the facility by the year 2000. A month later, the government signed an agreement with a consortium of Western companies to replace the station with a new gas-powered plant. But the deal could still fall through. Laying Chernobyl to rest will be a thorny and expensive problem for many years.
A shutdown would immediately soothe qualms about the two operating reactors. True, some new safety features have been added to these units. But since the breakup of the Soviet Union, parts, money for maintenance, and qualified nuclear workers all have become scarce. "These reactors are aging, and they're not operating under anything approaching Western standards of safety," says David Schwarzbach, a nuclear policy expert at the Natural Resources Defense Council in Washington, D.C.
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