By DOUGLAS BIRCH
Chernobyl becomes wildlife haven, intriguing biologists
Scientists are confounded by wildlife returning to the site of the world's worst nuclear spill PRISHEV, UKRAINE — Two decades after an explosion and fire at the Chernobyl nuclear power plant sent clouds of radioactive particles drifting over the fields near her home, Maria Urupa says the wilderness is encroaching.
Packs of wolves have eaten two of her dogs, the 73-year-old says, wild boar trample through her cornfield and fox, rabbits and snakes infest the meadows near her tumbledown cottage.
"I've seen a lot of wild animals here," says Urupa, one of about 300 residents, mostly elderly, who insist on living in Chernobyl's contaminated evacuation zone.
The return of wildlife to the area around the world's worst nuclear power accident is an apparent paradox that biologists are trying to understand.
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Many assumed the 1986 meltdown of one reactor, and the release of hundreds of tons of radioactive material, would turn much of the 1,100-square-mile evacuated area around Chernobyl into a nuclear dead zone.
It certainly doesn't look like one today.
Dense forests have reclaimed farm fields and apartment house courtyards. Residents and visitors report seeing wildlife near the site — including moose and lynx — rarely sighted in the rest of Europe. Birds even nest inside the cracked concrete sarcophagus shielding the shattered remains of the reactor.
Wildlife has returned despite radiation levels in much of the evacuated zone that remain 10 to 100 times higher than background levels — though they have fallen significantly since the accident, due to radioactive decay.
Some researchers insist that by halting industry from destroying their habitat, the Chernobyl disaster helped wildlife flourish. Others say animals may be filtering in, but they appear to suffer malformations and other ills.
Both sides say more research into the long-term health of a variety of Chernobyl's wildlife species is needed as governments around the world consider switching from fossil fuel plants, blamed for helping drive global climate change, to nuclear power.
Biologist Robert J. Baker of Texas Tech University was one of the first Western scientists to report that Chernobyl had become a wildlife haven. He says the mice and other rodents he has studied at Chernobyl since the early 1990s have shown remarkable tolerance for elevated radiation levels.
But Timothy Mousseau of the University of South Carolina, a biologist who studies barn swallows at Chernobyl, says that while wild animals have settled in the area, they have struggled to build new populations.
Far from thriving, he says, a high proportion of the birds he and his colleagues have examined suffer from radiation-induced sickness and genetic damage. Survival rates are dramatically lower for those living in the most contaminated areas.
In explaining their starkly differing views, Baker and Mousseau criticize each other's studies as poorly designed.
But their disagreement also reflects a deeper split among biologists who study the effects of exposure to radiation. Some, like Baker, think organisms can cope with the destructive effects of radiation up to a point — beyond which they begin to suffer irreparable damage. Others believe that even low doses of radiation can trigger cancers and other illnesses.
In the Journal of Mammology in 1996, Baker and his colleagues reported that the disaster had not reduced either the diversity or abundance of a dozen species of rodents near the Chernobyl plant.
"Our studies show that a dynamic ecosystem is present in even the most radioactive habitats," they wrote.
Baker's group reported sighting red fox, gray wolf, moose, river otter, roe deer, Russian wild boar and brown hare within a six-mile radius of the plant — the most heavily contaminated area.