With humans evacuated, wildlife flourishes in the "dead" zone (04/21/96)

With humans evacuated, wildlife flourishes in the "dead" zone

by Mary Mycio
Special to The Ukrainian Weekly

CHORNOBYL, Ukraine - Ihor Shokhalevich recalled the autumn evening he spotted a boar munching on apples outside the local drugstore.

"He wasn't bothering anyone," the biochemist said, smiling at the incongruous image of the tusked pig in what was a busy raion center before the Chornobyl reactor exploded and burned 10 years ago.

Since 135,000 people were evacuated in the disaster's radioactive wake, there haven't been many people for a boar to bother in the highly contaminated "zone of alienation" surrounding the power station.

Not surprisingly, many people imagine the zone as a barren wasteland killed by radiation. In fact, by forcing people to abandon the Rhode Island-sized region 60 miles north of Kyiv, the world's worst nuclear accident created a new ecological niche that is very much alive.

"The zone has become a wildlife refuge," said Mr. Shokhalevich.

Large animals that are especially shy of civilization have rebounded. The number of boars has increased eightfold since 1986. The moose population has doubled. Eagles, cranes and endangered black storks have reappeared. There are also more roebucks, wolves, foxes, otters and rodents than outside the zone.

"And there are no monsters!" insisted zone ecologist Vitaly Gaichenko in response to the inevitable questions about mutants. "If wild animals are weak, they die."

That so many creatures are, in fact, flourishing leads Chornobyl scientists to the surprising conclusion that for wildlife, the benefits of a human-free environment can outweigh even the biological costs of radiation.

There are no more than 10,000 people in the entire zone on a given day. Nearly all are in one of two places named "Chornobyl": the atomic energy station and this eponymous town 12 miles away, where the Administration of the Zone of Alienation performs its distopian task of governing the no man's land.

But in the evenings, when humans leave for lodgings in "clean" areas, a boar can dine a few blocks from Mr. Shokhalevich's office in the Chornobyl Research and Technical Center, undisturbed.

At least when Olof Eriksson isn't in town. The sporting Swedish scientist and Ukrainian zoologist Herman Panov bagged more than 60 boars and that many roebucks over three years to study how much radioactivity they were absorbing.

Indeed, because zone rules forbid hunting for sport but not hunting for science, the immediate danger to zone animals isn't from radiation but researchers on the lookout for guinea pigs.

Mr. Eriksson's study was one of hundreds conducted since the 1986 explosion and fire transmuted the zone into a radiological field experiment.

After 10 years, 95 percent of the cesium, strontium and plutonium in the zone have sunk about an inch into the topsoil and riverbeds. That's good because they are deep enough not to be spread by the rivers and wind, although they are also traveling very slowly to the ground water.

But it's bad because, from the soil, radionuclides - or radioactive atoms - get into the food chain, migrating into plants, the animals that eat them, and the predators, including humans, who eat both.

In the body, different radionuclides target different tissues where they can lodge, and bombard neighboring cells with atomic particles and, in the case of americium, gamma rays. In bone marrow, which makes blood, the resulting damage can produce leukemia. In ovaries, it can affect future generations.

"But the more we learn, the more we don't know," said biologist Victor Riasenko, who spent five years studying laboratory minks fed contaminated meat that delivered "relatively small doses."

The experiment began in still-Soviet 1990 when, to prove that it hadn't bungled dismally, the Soviet government tried to show that the zone could still be put to economic use. Mink farming was thought to be a good idea.

As it turned out, radiation didn't get into the minks' fur, but their pelts shed within a year. Minks born in the zone failed to thrive. Their numbers shrank with each generation. Of the fourth, none survived weaning.

"This showed that even small doses aren't so small when they're internal," Mr. Riasenko concluded. "And the minks that lived the longest were those that were born and weaned in clean areas."

Wild animals are also accumulating radionuclides. Mr. Eriksson bagged some boars and roebucks with more internal cesium than the Lapland reindeer of his native Sweden absorbed in the early months after the disaster.

In his study of Chornobyl rodents, University of Texas geneticist Robert Baker also found large numbers of cesium - and large amounts of rodents, even in places where background radiation is 100 times normal.

"I was a little surprised at how well living things are doing," said Mr. Baker.

Still, Mr. Baker also found genetic mutations in some rodents could bode ill for their future. Chornobyl mice also have depressed immune systems and, like Mr. Riasenko's minks, die younger and reproduce less. Moose, too, are more often seen with one calf rather than the usual two.

Although there are now more mice and moose and other creatures in the zone than outside its 139-mile perimeter, scientists don't know if those biological costs won't eventually come to outweigh the habitat's human-free benefits.

A "pessimistic optimist," Mr. Riasenko thinks that the diversity and number of animals will decline as the Chornobyl environment winnows out weak species and individuals. But the survivors of the Darwinian struggle, "though fewer in number, will be more resistant to radiation," he said.

"Evolution in the zone has speeded up," said ecologist Mr. Gaichenko. "But we need at least 20 more years to see the direction it's taking."

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