Toxic threat to Danube 'eliminated' claims PM as death toll climbs to 7

The spill has left red sludge across the region

Hungarian government officials lowered their estimate of the size of Monday's catastrophic spill - but even those figures were mind-boggling. They said the reservoir break at an alumina plant dumped up to 184 million gallons of sludge onto three villages - not much less in a few hours than the 200 million gallons the blown-out BP oil well gushed into the Gulf of Mexico over several months beginning in April.

Meanwhile, the disaster's confirmed death toll rose from four to seven. An 81-year-old man died yesterday from injuries sustained in the torrent and two bodies were found on the outskirts of Devecser. The unidentified victims were likely two of the three Kolontar residents still missing, rescue agency spokesman Tibor Dobson said.

The location of the bodies suggested they were swept over two miles by the torrent.

The red sludge devastated streams and rivers near the spill site and entered the Danube on Thursday, moving downstream toward Hungary's immediate neighbours, Croatia, Serbia and Romania. Monitors were taking samples every few hours to measure damage from the spill, but the sheer volume flowing in Europe's second largest river appeared to be blunting the red sludge's immediate impact.

Prime minister Viktor Orban said the threat to the Danube had been eliminated, and the International Commission for the Protection of the Danube, a Vienna-based group that monitors the river and its tributaries, agreed.

The pH level of the water where the slurry entered the Danube was nine - well below the 13.5 measured in local waterways and not too damaging to the environment, Mr Dobson said. A neutral pH level for water is seven. Each pH number is ten times the previous level, so a pH of 13 is 1,000 times more alkaline than a pH of ten.

However, the risk of pervasive and lasting environmental damage remains, with Greenpeace presenting laboratory tests it claimed showed high concentrations of heavy metals in the sludge.

Red sludge samples taken on Tuesday, a day after the spill, contained "surprisingly high" levels of arsenic and mercury, Greenpeace said. . The analysis suggested roughly 50 tons of arsenic, 300 tons of chrome and half a ton of mercury was unleashed by the spill, Greenpeace officials said. They added that the detected arsenic concentration was twice the amount normally found in so-called red mud, a waste product in aluminium production.

Analysis of water in a canal near the spill found arsenic levels 25 times the limit for drinking water, Greenpeace said.

With rain giving way to dry, warmer weather, the caustic mud was increasingly turning to dust, which can cause respiratory problems, said Zoltan Illes, Hungary's environmental chief. Emergency officials urged residents near the toxic flood area to wear face masks.

The warnings conflicted with the view of the prestigious Hungarian Academy of Sciences, which reiterated yesterday that the red sludge remained hazardous due to its caustic alkalinity but its heavy metal concentrations were not considered dangerous for the environment.

"The academy can say whatit wants," said Barbara Szalai Szita, who lives in Devecser, one of the hardest-hit villages. "If I spend 30 minutes outside I get a foul taste in my mouth and my tongue feels strange."

Yesterday, experts from the Research Institute for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences took fresh samples of the earth tainted by the red sludge for analysis. "The consistency of the red sludge stopped the respiratory activity of the soil and the normal microbial life in the soil," institute director Attila Anton said.

Mr Dobson said 26 million gallons of fluid from a storage pond close to the burst reservoir was being gradually released into a local river already declared dead after Monday's catastrophe. Gypsum was being dropped into the Marcal River from helicopters to neutralise the alkaline effect of the fluid, he said.

It is still not known what caused a section of the reservoir to collapse but a criminal investigation is under way.