Brazilian mining giant Vale says that small amounts of arsenic and other potential poisons have been detected in a river polluted by an iron ore mine accident, but that the mining companies are not to blame.
Vania Somaville, director of human resources, health and safety at Vale, on Friday (local time) told a press conference that lead, arsenic, nickel and chrome had been detected at some points along the River Doce in south-eastern Brazil.
However, Somaville said the potentially dangerous contaminants were not carried down by the torrent of waste water and mud unleashed when a dam broke at the Samarco iron ore mine on November 5. At least 13 people died and about 11 remain missing from the flood.
"They were (already) there at the edges or in the bed of the river" and were disturbed in the flood, she said.
"The good news is that these materials did not dissolve in the water" and are now diminishing, she said.
Vale, the top iron ore miner in the world, is joint owner of Samarco along with Australia's BHP Billiton, the world's biggest mining company, which also denies that the flood caused serious pollution.
This is in stark contrast to a report by two UN experts on Wednesday accusing the corporations and the Brazilian government of failing to respond to a toxic disaster.
The UN's special rapporteur on human rights and the environment, John Knox, said the equivalent of "20,000 Olympic swimming pools of toxic mud" spewed into the River Doce.
Vale's CEO, Murilo Ferreira, told the press conference in Rio de Janeiro that a major fund would be established to help clean up the mess. Ferreira did not say how much money would be in the fund, but that it would be "longterm" and open to international audit from government and non-governmental bodies.
Ferreira has been criticised by environmental activists for what many saw as his slow response and his attempt to distance himself from the tragedy by saying that Vale was only a shareholder in Samarco.
He told journalists on Friday in a breaking voice that "the disaster has been extremely painful" for him and other executives.
"My soul is saddened and disturbed.... We are very worried that there are 5200 people who don't know what the future holds," he said referring to the many jobs suspended in and around Samarco after the accident.
However, Ferreira once more sought to draw a distinction between Vale and the Samarco operation, saying that help was being offered only out of "solidarity."
"In four years I was never at the Samarco offices in Mariana," he said. Until the accident "I didn't know them.... We don't know who their clients are or their prices."