from New Scientist, 16 May 2002
Huge dumps of toxic waste from old Soviet uranium mines are threatening to contaminate the water supplies of millions of people in Central Asia. Up to 23 dumps along the Mailuu-Suu river in southern Kyrgyzstan are at risk of leaking because of landslides and flooding in recent weeks.
Over two million tonnes of uranium wastes were left behind by a mining and milling complex which fuelled the Soviet nuclear programme between 1945 and 1968. Tipped into piles or dropped into holes, it has long been "an accident waiting to happen", according to experts from the World Health Organization.
Kubanychbek Monolbaev, a Kyrgyz environmental health scientist with the WHO in Bonn, says that the area is prone to earthquakes, as well as landslides and floods. Downstream is the Fergana Valley, home to over six million people from three countries, as well as major rice and cotton plantations.
Recent reports from Kyrgyzstan suggest that, following six weeks of rain, a large landslide on Sunday blocked the Mailuu-Suu river and caused widespread flooding. "This is dangerous", says Monolbaev, who inspected the region in 1995, because none of the dumps have any engineered defences.
Chemically toxic
They contain uranium tailings, which are radioactive and chemically toxic, as well as arsenic and perhaps other heavy metals. Gerhard Schmidt, a German researcher who has studied the area's mining legacy, warns that leaks from some of the waste dumps could make water in the Fergana Valley unfit to drink.
There are two dumps near the river which contain "relatively high" levels of uranium decay products, he says. These include thorium 230, radium 226 and lead 210, which have the potential to cause serious long term pollution.
After visiting the area in 1998, Schmidt, who is based at the Oko Institute in Darmstadt, called for these two dumps to be moved to a safer place. The government of Kyrgyzstan has been appealing for financial help from other countries to help tackle the problem.
Earlier this week, the Kyrgyz deputy prime minister, Nikolai Tanaeyev, said that landslides around the Mailuu-Suu river were potentially very hazardous. If the uranium dumps were washed away, he pointed out, "it would represent an ecological catastrophe for the whole region".
