Little cyanide peril is seen for DanubeTributary Badly Polluted but Scientists Minimize Danger to Humans
By Peter S. Green
Paris, Monday, February 15, 2000
PRAGUE - A wave of toxic cyanide making its way down the Danube River has left tons of dead fish in its wake and could damage the ecological system of a key tributary for months or years, environmental experts and local officials said Monday.
But the scientists and officials said the cyanide, from a gold mine in Romania, would most likely do little lasting damage to the Danube itself, and that the danger to humans along the river was minimal.
They said the Danube could recover quickly as the cyanide is diluted and broken up into neutral chemicals.
"The amounts of cyanide that leaked - it's big," said Pasi Rinne, a senior United Nations environment official who has flown to Belgrade, on the banks of the Danube, to assess the damage. "But I would hesitate to speak about an environmental catastrophe."
Accurate information on the spill's effects, and on the contents of the spill itself, has been difficult to come by, but scientists say the Tisa, which was the first river hit by the waste, was far more badly hit than the Danube. They said the faster-flowing Danube would easily dilute the cyanide, although some fish and marine life could die there, too.
Vlasta Pujin, a professor at Novi Sad University in Yugoslavia, told Agence France-Presse that the cyanide leak would probably prevent fish from spawning in the Tisa this spring. "In that case, the decline of fish life is inevitable, and I am afraid it will need several years to recover," he said.
Already on Monday, fishermen and civil defense workers in Hungary and Serbia had pulled at least 83 tons of dead fish out of the Danube and the Tisa, and in some towns, Serbian policemen were checking markets to keep polluted fish from sale. Scientists said that the spill had not yet affected the Danube and that much of the dead fish collected there had been washed down from the Tisa by surface waters that flow faster than the deeper waters pushing the pool of toxic waste.
They said that cyanide, unlike toxic heavy metals such as mercury and waste such as PCBs (polychlorinated biphenyls) would not build up in the ecosystem.
But scientists said there is very little that can be done to dampen the effects of a cyanide spill except to hope that it gets diluted to safe levels. Bacteria that break down cyanide naturally are rare in most rivers.
Approximately 100,000 cubic meters (3.5 million cubic feet) of cyanide-laden sludge and waste water spilled into the Tisa, a Danube tributary, on Jan. 30, when a dam burst at the Aural gold mine in Baia Mare, Romania. The cyanide was part of a toxic cocktail used to recover gold and silver from ores mined nearby, in an operation half-owned by an Australian mining company, Esmeralda Exploration.
The pollution is moving slowly, deep in the Tisa River, in a "plug" 6 to 8 kilometers (3.7 to 5 miles) long, the UN's Mr. Rinne said, and it should reach Pancevo, Yugoslavia, on Tuesday morning and Belgrade by late afternoon or evening.
Hungarian and Serbian officials said the damage on the Tisa had been devastating, but that there was so far no scientific evidence to back them up.
The Belgrade municipal waterworks announced it had shut a riverside purification plant as a precaution Monday.
An Esmeralda official told the Reuters news agency from Perth, Australia, that his company was not responsible for the dead fish and questioned whether cyanide from the mine was actually the cause.
Even before this spill, the Danube was one of the Europe's most polluted rivers, ravaged by decades of Communist-era industrialization. NATO bombing of Yugoslavia during the Kosovo war also harmed the Danube.
The damage caused by the cyanide spill has already pitted the Balkan neighbors against each other, with Hungarian officials accusing Romania of playing down the spill's significance, and Yugoslav officials threatening to bring Romania before the International Court of Justice in The Hague.
As the poison surged downriver, Serbian officials Monday banned all use of Danube water downstream from Belgrade after detecting high levels of cyanide near Zemon and Pancevo on the Danube's left bank, AFP reported.
But some damaged areas were already beginning to recover. Cyanide levels were below European-accepted norms in Romania and plankton was back to half the normal levels, Septimius Mara of the Romanian Environment Ministry said.