Silver Lining to Brazil’s Mining Pollution Cloud

For a nation that’s justifiably proud of hosting 20% of the world’s biodiversity, Brazil is coming to terms with a man-made environmental disaster that has all but eradicated biodiversity along the valley of the Rio Doce, a river flowing 500km from the heartland state of Minas Gerais to the Atlantic seaboard.

The baroque, colonial era towns of Minas Gerais may not have been touched, yet a more precious part of  the nation’s heritage has been wiped out. Brazilians have reacted with anger and disgust at the harrowing TV footage of entire villages along the river valley deluged in reddish iron ore-heavy mud; at images on social media of the river’s fish population floundering and dying; and at aerial shots of the vast cloud of turbid water leaking into the sea, which has raised fears the pollution could stretch even beyond territorial waters. Whales, sharks and marine turtles could all be affected.

The lack of oxygen and high temperatures caused by the pollutants has killed off much aquatic life both in the entire river and the sea near its mouth. Fixing the disaster calls for a restoration project on a scale exceeded in recent times only by the marine cleanup after the BP Deepwater Horizon in the Gulf of Mexico.

fish are dea

Images such as these illustrations  of the fish rescue operation and the cleanup taken from Brazilian social media, reflect a new and angry mood of environmental awareness and engagement among younger people. This is in marked contrast to the indifference that for many decades characterized Brazilians’ response to a painful catalogue of environmental destruction wrought by industry and agribusiness. Now Brazil’s excellent environmental legislation – often honoured in the breach – will be rigorously enforced out of political necessity.


While the blame-calling and pre-litigation jousting rages between the Brazilian government and the owners of a mine whose waste-water dam burst November 5th, killing 13 people, scientists are just beginning to address the challenges posed by the disaster. At a time when government budgets for almost all science and research are being slashed in response to a deep recession, this disaster spells huge opportunity for many scientists who could spend years restoring the Rio Doce to life. Harsh though it sounds,  for Brazil’s cash-strapped science community, there is now big, big money in pollution.


Two multinationals, BHP Billiton and Brazil’s own state-controlled Vale – formally entitled Companhia do Vale do Rio Doce in recognition of its industrial history in the now-stricken valley – face a huge bill for this cleanup of the mine tailings that spilled from their broken retaining dam. The Brazilian government is demanding BR$20 billion ($5.2bn) from mining company Samarco (the BHP Billiton- Vale joint venture) and Environment Minister Izabella Teixeira said money was needed for environmental recovery and to compensate victims.

If this money is forthcoming, then local ecologists and conservations can look forward to something of a bonanza. Indeed, the total may even exceed this. One proposal presented to Brazilian president Dilma Rousseff by the famed photographer Sebastião Salgado, who runs a reforestation project in the river valley that was partly funded by Vale its, calls for funding of BR$100 billion – or over US$25 billion – to rebuild the long-degraded Rio Doce valley habitat with a monumental tree-planting programme.

aerial view2

Salgado’s numbers may not be so fanciful: After the 2010 oil rig disaster, the Deepwater Horizon Oil Spill Trust was funded at $20 billion. To deliver this, BP posted its US assets worth $20 billion as bond and had to both sell assets and sacrifice dividend payments for several years.

Federal environment protection agency IBAMA is planning additional fines against Samarco, which has agreed to pay the Brazilian government BR$1bn ($260m) in compensation, to cover an initial clean-up and to offer some compensation to the victims and their families. If the Brazilian government gets its initial $5.2 billion, the proceeds would be put in a fund and used for environmental cleanup in the Rio Doce valley over 10 years, according to Attorney General Luís Inácio Adams. Already, Vale and BHP announced a fund for Samarco to help fund the clean-up of the Rio Doce and its tributaries.

Whatever happens, the need for people and resources to mitigate man-made pollution on the heroic scale shown by the image above, will be significant. A UN report said the dam burst at the Samarco mine unleashed a flood equivalent to “20,000 Olympic swimming pools of toxic mud.” The UN and Brazil’s environment agency have both tested the red-looking sludge, and say it contains toxic chemicals, including arsenic levels at 10 times above the legal limit and other harmful metals, including zinc, copper and mercury.

This is refuted by BHP, which said in a statement that the water in the dam did not pose any threat to humans and is not toxic. BHP insists that “The tailings that entered the Rio Doce were comprised of clay and silt material from the washing and processing of earth containing iron ore, which is naturally abundant in the region.”

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While the miner is confident the red mud now covering an 80 km-long swathe of the flood plain would “behave in the environment like normal soils in the catchment,” residents believe that as it dries it will form a concrete-like skin, making all agriculture impossible. Because of the pollution risk, all supplies of drinking water have been cut off for a quarter of a million people in communities living the valley, who now depend on bottled water.

Furthermore, some reports indicate the possibility of species extinction. Biologist Andre Ruschi, director of the Augusto Ruschi, biology centre in nearby Espirito Santo, was quoted as saying: “There are animal and plant species here that we can consider extinct as from today.” He added that the Rio Doce spill is “the biggest environmental disaster in the history of the country.” According to Ruschi, the mine tailings are affecting a marine area of around 10,000 sq km on the Espirito Santo coast that includes the Costa das Algas and Santa Cruz marine conservation habitats.


What’s becoming clear is that Rio Doce – one of Brazil’s most important rivers – would have to be dredged in parts, vegetation replanted and fresh water springs cleared. Restoration of this habitat, including removal of heavy metals and other pollutants if they are indeed proven to have been present in the dam tailings and to have seeped into the groundwater, is a task that could employ a generation of ecologists and conservationists.

So far, the question of whether Brazil has the domestic capacity in terms of having enough scientists to man and execute the cleanup, has not really been asked, let alone answered. With large sums in play and multinationals seeking to protect their international reputations, their first thoughts will be to deploy international experts able to help heal both the environmental damage and the damage to these companies’ record of corporate citizenship.

But biodiversity specialists of all stripes – from marine and freshwater conservation biologists, and toxicologists, though soil structure geologists, reforestation experts, entomologists and even materials scientists or engineers trained in assessing load factors on the dozens of other potentially dangerous min tailing dams scattered across Brazil – could all have their day in the sun.

Mining has been the heart of Mariana since colonial times in Brazil, when the town was the main source of gold for the Portuguese Empire. Since the 1970s, when Samarco built its dams and dug its mines here, iron ore has taken over as the main source of income. With the collapse of the commodities supercycle and a long period of low prices for iron ore forecast, the next big boom in the region may turn out not to be to be mining, but mitigating its harmful effects.

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