Threat of mercury poisoning rises with gold mining boom

I went instead to the town of Amalfi, visiting a small mine with modest quarters for sleeping six, a privy, and a kitchen. Under a tin roof were eight ball-mills, lined up next to each other near an opening in the rock face just wide enough for a cart the size of a small sled to be wheeled down into the darkness.

The mine starts as a sharply sloping tunnel descending 50 or 60 metres, before leveling off into the first large opening where dynamite had blasted a space big enough to stand upright. From here the miners had followed quartz veins, expanding underground into a disorienting series of tunnels that dip another 50 metres, leaving you fatigued from ducking beneath low clearings and squeezing between narrow walls.

Carted up from the mine below, the ores are run through a sluice to strain and separate large from small rocks, then combined with mercury in the ball-mills where they are ground for five or six hours. After that, the floured concentrate is panned in a wide-lipped cedar bowl, until what’s left is the gold and mercury amalgam, ready to be burned.

“Of course we know miners who are mercuried,” said Cesar Zapata, the mine’s operator. “We want to change. The problem is we don’t know how, and we don’t have means. And we don’t have means because we are not legal.”

Many miners are aware of the danger posed by mercury. One common practice to keep from inhaling mercury vapour is for miners to hold a large leaf over the roasting amalgam. “The problem,” said Oseas García Rivera, who directs a mercury pollution project administered jointly by the government and UN, “is they take that leaf and go like this” - he pretended to throw something into the forest - “so the mercury ends up in the environment anyway.”

Garcia is among an increasingly vocal wing of development practitioners who view environmental needs as inseparable from questions of poverty and property. Only when miners have access to credit and capital, the thinking goes, can they invest sustainably in pollution controls. And without formal mining claims, small-scale gold miners in Colombia and elsewhere have no collateral against which they can borrow.

But mobilising governments to recognise mineral rights in the small-scale mining economy is a struggle, especially when foreign companies wield influence through investment in large-scale resource extraction.

Among small-scale miners, the perception is they are engaged in a game that is rigged against them. “The companies arrive and the laws are immediately changed to help them, while we have to wait ten years to get titles,” says Roberto Lema Castro, president of a national miners association called Fenamicol.

Such problems present a vexing paradox: Acute environmental health crises such as urban mercury emissions demand immediate intervention, yet sustainable solutions lie in healing deeper social and political afflictions.

“We have too many problems to expect one big solution,” García Rivera says. “But what we can hope for is to get a group of entables, five or ten, to try a different way, and use mercury as an excuse, a tool, to create a progressive process.”

Alexandra Castano contributed translation and reporting for this article.