Ronneburg, Germany, looks like a mining town in Wales or West Virginia. Huge piles of waste rock and old mining equipment are as much a part of the landscape as the rolling foothills of the Ore Mountains (Erzgebirge) – the range that forms the German-Czechoslovak border. Many of Ronneburg’s residents, like those in the neighbouring towns of Aue, Schlema and Schneeberg, used to unearth uranium for the area’s one mining company, Wismut.
Since the 12th century, mining has been a tradition in the region. Silver, nickel and cobalt are also among the ores that were dug from mines spread over an area of 1000 square kilometres. Now, nearly a millennium after it began, the territory’s history as a mining region is coming to a close. At the end of last year, Wismut halted production at its six uranium mines and, in the process, made more than 10 000 miners redundant (This Week, 2 February).
The company’s operations were uncompetitive: the cost of its uranium was three times the world price. This did not matter when Wismut sold everything it mined to the Soviet Union and East Germany. Since reunification, however, nuclear power plants in what was East Germany are being shut down and, with the halt in the nuclear arms race, the Soviet Union no longer needs as much uranium as it once did.
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Wismut must now submit detailed plans for cleaning up the region to Germany’s environment and economic ministries. But the task has strained Wismut’s technical resources to the point where the company is seeking the help of experts from Australia, Canada, France and the US.
Decommissioning the largest uranium mining operation in Europe – in the 1980s, Wismut made East Germany the third-largest producer of uranium after the US and Canada – is an enormous logistical and technical challenge. Reunification only complicates matters as it has meant a complete reorganisation of the authorities and stiff competition for government funds.
But what most concerns Wismut, and the German authorities to which it reports, is the high concentrations of radioactive radon gas, a decay product of uranium, that permeates not only the mines but also the homes in the region. In one town, the gas is generating levels of radioactivity as high as 100 000 becquerels per cubic metre – 500 times the maximum level advised by Britain’s National Radiological Protection Board. According to Klaus Hinkel, a former Wismut miner who is now helping the company to organise the cleanup, the East German operation had no counterpart. ‘The uranium operations in Australia, Canada and the US, although large, are all located in less densely populated areas.’
¿ìè¶ÌÊÓƵs are investigating the scale of the radon contamination to try to find out whether it is the result of Wismut’s operations, earlier mining or natural conditions. Their results will determine how much cleanup work needs to be done and who should pay for it – Wismut, the German government or the residents themselves.
The issue of radon contamination raises serious epidemiological questions. How much is radon to blame for lung cancers in the region? Are the cancers the result of working in the mines or of living in radon-contaminated homes? One problem facing researchers is that records of radiation exposure for miners and residents were not kept until 1954 .
The gargantuan scale of the Wismut operation does not make the cleanup or epidemiological studies any simpler. Around 1600 kilometres of tunnels must be filled and sealed, along with about 140 mine and ventilation shafts and six underground caverns. Some excavations are as deep as 2 kilometres. Equipment must be disposed of, either by selling it intact or as scrap, if it is not too badly contaminated, or by burying it in the mines if it is.
On the surface, Wismut must deal with thousands of huge heaps of waste rock, one of them as large as 130 million cubic metres. The radioactivity of the heaps in Ronneburg is between 0.65 and 0.7 becquerels per gram – nearly four times the recommended safe limit in Germany. In Britain, special authority is required to dispose of material that is more radioactive than 0.4 becquerels per gram. These heaps must be isolated from ground water supplies, secured to prevent avalanche, erosion, and dust contamination, and either levelled, carted away or covered and replanted.
The company must also decontaminate 18 tailings ponds, where sludge left over after uranium was extracted from the mined rock was left to dry. The radioactivity of two of the largest ponds, stretching over 250 hectares, is 10 becquerels per gram. If the ponds cannot be cleaned, they must be isolated from ground water supplies and covered. Wismut must also check the stability of the dams impounding the ponds.
Radioactive particles are not the ponds’ only contaminants. Heavy metals and toxic chemicals, such as sulphuric acid, sodium hydroxide and an array of chlorides, ammonium salts and hydrocarbon compounds, are also present. Wismut estimates that water containing 20 grams per litre of sulphate and 2 grams per litre of iron has been leaching out of the ponds into ground water. These concentrations are, respectively, about 100 and 10 000 times as high as Germany permits in drinking water and scientists are now checking what effect they have had on ground water supplies .
The unwelcome legacy from the mining operation has its origins in the unique history of Wismut itself. Until the collapse of the East German government last year, Wismut differed from most western mining operations because the company was state-owned by the Soviet Union and East Germany rather than corporately owned. Political rather than economic goals were its priority. The key consideration was to mine as much uranium as quickly as possible to make the nuclear weapons and energy industries independent of foreign supplies of raw materials. Cost, worker safety and environmental pollution were of little concern, at least initially.
Underground risks
From its inception in 1946, the operation was top secret. Described as a ‘state within a state’, Wismut had its own police, health services and power-generating plants. Radiation levels were measured by Wismut employees and recorded only in the company’s archives in Karl-Marx-Stadt, now renamed Chemnitz.
The Soviet Union relinquished its half stake in Wismut last month, leaving Germany with full responsibility for the cleanup – and the bill for up to DM15 billion ( £5 billion). Although the company will not officially change hands until 30 June, the German economics ministry has begun to restructure the enterprise and prepare it for privatisation.
But the change of ownership has done little to speed the cleanup process. Lacking any experience of uranium mining on such a scale, the Bonn government has no standards to guide the decommissioning work. As a stopgap, it is applying old East German laws but is otherwise reluctant to rely on practices established by what it regards as a discredited regime. This is frustrating for people like Konrad Barth, the mayor of the mining town of Schlema and a former miner: ‘People ‘over there’ (in the West) think that just because something was done in East Germany, it was done wrongly, and that’s not the case. It was a mistake to keep things secret, because in addition to hiding our mistakes, we also hid the things we did well.’
Wismut is now making a visible and concentrated effort to display openly its expertise to local and federal authorities and to the public, but its rehabilitation may take some time. Residents near the mines, and even some former employees, remain sceptical about the accuracy of the company’s statements. And Germany’s environment ministry is having all Wismut’s work on decommissioning the mines checked independently.
Reorganisation of the former East German regulatory and local government authorities has also hindered progress. More than a year ago, at what was then East Germany’s National Board of Atomic Safety, a joint East-West government commission laid plans for 15 environmental assessment projects in the mining region. Since then, the board has become part of Germany’s Federal Office of Radiation Protection and has lost a third of its staff. The budget for all but one of the projects has yet to be approved.
Assessing the impact of the mine on the region and its people poses another enormous challenge. From 1946 to 1954, when the mine was controlled solely by the Soviet Union, conditions were primitive. Werner Schuttmann, a retired doctor who then worked in the region, recalls that up to 100 000 miners drilled for ore without dampening down the dust; ventilation was inadequate and air quality poor. His warnings about the dangers of radioactive dust went unheeded. ¿ìè¶ÌÊÓƵs now estimate that the miners were exposed to doses of radiation of between 300 and 3000 millisieverts per year. In Britain, the NRPB recommends that workers should not be exposed to more than 15 millisieverts per year, or 50 millisieverts per year in exceptional circumstances. According to Wismut, current levels of radioactivity in the mines would expose workers to doses of between 10 and 40 millisieverts per year.
After 1954, when Wismut became a joint Soviet and East German enterprise, conditions in the mines improved. The company says that dust became less of a hazard as drills were introduced that automatically watered it down and new ventilation systems provided miners with 90 cubic metres of fresh air per minute. Wismut began to record the levels of radioactivity every month, though it did not issue miners with personal dosimeters. According to a report by the former East German National Board of Atomic Safety, radiation doses ranged from 100 and 1000 millisieverts per year between 1956 and 1960. By 1975, they had dropped to current levels.
But the changes were not made soon enough. By the end of 1989, there were 5132 reported cases of miners with lung cancer, of whom 98 per cent are thought to have contracted the disease before 1955, says Klaus Martignoni, head of the section of Germany’s Federal Office for Radiological Hygiene dealing with the somatic effects of radiation. This figure is disputed by the German environmental magazine Atom, however. In its May issue, the magazine says that there are more than 9000 cases of miners with lung cancer.
Epidemiologists from Germany’s Ministry of Health, the Federal Office of Radiation Protection and the Federal Office of Radiological Hygiene are currently working in cooperation with their colleagues at what was the East German Central Institute for Epidemiological and Health Research to learn more about the health consequences of working in the mines.
According to Martignoni, the study will be larger and may last longer than those undertaken in Japan after atomic bombs were dropped on Hiroshima and Nagasaki. The first results will be ready in 1995, and investigations will continue until the last miner employed by Wismut dies.
To help keep a track on the health of miners who have left the region, epidemiologists plan to use Wismut’s own records and the East German Cancer Register, a detailed record of all the cancer cases. Martignoni says the data could be used to determine if there is a link between the incidence of cancer and the radiation doses miners received while working for Wismut. Researchers will thus be able to assess the effectiveness of the radiation protection measures introduced in 1955.
For the study, miners will be divided into three groups according to when they began working for Wismut: before 1955, when no occupational safety measures existed; between 1955 and 1970, when wet drilling and monitoring of radiation levels were standard practice; and after 1970, when there were improvements in ventilation and monitoring procedures.
Determining the levels of radiation in the mines before 1955 will be the most difficult part of the study, says Martignoni. To help them to estimate the levels, researchers will draw on records of working mines in Canada, Czechoslovakia, France and the US. They may also try to simulate early working conditions in Wismut mines.
Epidemiologists could also study the correlation between different levels of radon dust exposure and the incidence of leukaemia and skin and lung cancer. Or they could investigate the influence of compounding factors to discover the effects of smoking and the inhalation of diesel fumes on the incidence of the disease, says Martignoni. ‘This is something that hasn’t been done in Canada, Czechoslovakia or the United States.’
Like other Wismut investigations, the epidemiological studies are being hampered by Germany’s rapid reunification. According to Wismut, DM1.2 million of the company’s DM833 million cleanup budget for 1991 has been earmarked for maintaining employees’ health records. But researchers may be frustrated by problems with the cancer register. Funds are not available to transfer it to a modern data base and Germany’s stringent privacy laws may actually forbid its use for certain scientific purposes. ‘The health ministry has money to maintain it through 1991,’ says Martignoni, ‘but after that, it’s uncertain. Of course, our work will be affected if we don’t have access to it.’
Taryn Toro is a freelance writer based in Berlin.