WHEN the wind blows hard from the west, a swirling ocherous cloud descends on Oberrothenbach. Within minutes, a layer of fine-grained sand covers the hamlet's roofs, courtyards, roads, and cabbage fields, sifting through window sills, doors, and ceiling boards.
"It gets into everything," says Charlotte M138&gt;nnel, pointing to dust trails gusting off the slope of a vast slag heap and sludge pond 300 yards behind her home.
"You can feel it grit between your teeth when you eat. When it rains, the rainwater runs milky around the house," she says.
The ubiquitous dust is contaminated with Radium 226 and toxic chemical wastes.
For more than 40 years, Oberrothenbach, a cluster of houses just north of the industrial city of Zwickau, was a dumping ground for radioactive wastes produced by Wismut, a now-defunct Soviet-East German mining conglomerate.
Wismut's mining operations spanned dozens of other villages across a sprawling area in the south of eastern Germany, stretching 70 miles from just outside Gera to the Czechoslovak border to the southeast.
The extent of the environmental damage caused by Wismut has stunned officials in Bonn, who have just finished a preliminary review of conditions in the region. The area will be the biggest single cleanup job in all of eastern Germany, they say. The effort will take decades, they add, and require the decontamination of scores of buildings and thousands of acres of soil and lakes laced with uranium wastes, heavy metals, arsenic, and other toxic compounds.
Moscow signed over its share of Wismut to the German government in May, ridding itself of any ecological liability. Officials say cleanup could cost more than 15 billion marks ($9 billion).
"There was really no hope of ever getting the Soviets to help share the costs of the cleanup," said a high-ranking Economics Ministry official, after the German government agreed to shoulder all costs for the shutdown and conversion of the mines.
The Soviet Union began a crash program to match the United States nuclear capability after the US dropped atomic bombs on Hiroshima and Nagasaki in 1945. It ordered a massive effort to dig uranium out of rich lodes in occupied East Germany.
Between 1945 and last January, East German workers mined uranium for Moscow. At Wismut's giant mines, some with shafts up to 5,900 feet deep, the laborers extracted 220,000 tons of uranium ore for Soviet nuclear production. The ore was processed and train loads of the resulting "yellow cake" were regularly shipped to the Soviet Union.
Only mines in Canada and the United States have produced more uranium ore.
About 300,000 Germans, many of them forced laborers (refugees from the eastern territories, prisoners of war, and Nazi officials), worked at Wismut's mines in the first years after the war. The mines were run directly by the Soviet Defense Ministry until Communist East Germany was given a 50 percent share of Wismut in 1954.
Entire villages fell victim to widespread strip-mining operations. People in many of the towns that survived intact have since learned that tons of soil from the slag heaps frequently used in village construction and grading projects are contaminated with radium. Ground water supplies in many areas have also been polluted.
Production wastes from Wismut's processing plants, including radium, were routinely pumped into unsecured lagoons bounded only by earthen berms or simply dumped on the ground, forming about 3,500 slag heaps that tower above shabby mining towns.
Environmental officials in Bonn say high concentrations of radon gas, nearly 20 times levels found in basements in Munich, have been found in dozens of homes near the mines. Radon gas, which scientists say is a cancer-causing agent, is formed by decaying radium.
The uranium processing plants pose a particular threat and will receive priority in cleanup efforts, says Wolfgang Kemmer, a Wismut specialist at the federal Environmental Ministry in Bonn. Work crews are already spreading covers over sludge ponds, landfills, and other exposed dump sites to reduce the spread of contaminants.
Closing the mines will be a mammoth job.
"There's a huge amount of cleanup work in the shafts themselves," says Mr. Kemmer. "Contaminated equipment, including locomotives, giant cooling systems, and miles of train track will have to be pulled out."
The human costs of Wismut are also staggering. Because health statistics in the region were suppressed or falsified by the Communist regime, there are no precise numbers of workers who died from radiation exposure or of how many may still be affected.
Preliminary figures indicate at least 6,600 miners died of what was diagnosed as lung cancer caused by radiation exposure in the 1950s and '60s. Officials estimate that another 14,500 people have other lung diseases linked to exposure to radon gas and additional mine pollutants.
The worst health effects are found in Wismut workers, environmental officials say, adding that many deaths occurred as a result of early, more reckless, Soviet-led mining operations.
"Wismut is one of the greatest radiation catastrophes since Hiroshima. Only Chernobyl surpasses us," says Martin Jonsson, a physician who treated many Wismut workers.
"We were never really told our work was unusually dangerous," says Manfred Honesch, who drilled and blasted uranium in pits near the village of Schlema for more than 20 years. "A lot of people desperately needed the work, and you didn't really think about whether it was making you sick."
Despite suspicions about the dangers, workers were lured to the mines in droves by the promise of good pay, extra rations, and privileges. When uranium mining ceased in January, Wismut workers earned more than three times the average East German wage.
Before East Germany's anticommunist revolution in 1989, Wismut was virtually a state within a state, with its own Communist Party organization, car license plates, utility company, and a special wing of the Stasi security police to control it.
Wismut's top-secret operations were protected by barbed-wire fences and spotlights. Armed guards patrolled plant and mine perimeters.
Even the choice of the conglomerate's name was a deliberate attempt at concealment. "Wismut" is German for the metallic element bismuth.
Wismut, which had 39,000 employees in early 1990, plans to cut its work force to 18,000 by the end of this year. Further cuts are certain, despite plans to salvage Wismut's transport and road-building operations.
Remaining workers are shutting down the mines and production plants, clearing shafts before they are flooded and sealed for good.