Travels with Mercury: Small-Scale Gold Mining in Indonesia

About a month ago I found myself clinging with both hands to the back of a motorcycle, travelling through what looked like a desert landscape. In fact, I was in Central Kalimantan, on the island of Borneo, where the landscape was once unbroken, dense green vegetation, with orangutans swinging through the trees.

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Those trees are long gone; instead of dense vegetation, there are unbroken miles of sandy mining waste, the handiwork of thousands of small scale miners, looking for gold. I was riding over the barren lands already worked by the miners, in order to reach the active mining operations.

I had been invited by a local NGO, the Yayasan Tambuhak Sinta (YTS), and by Dr. Kevin Telmer, a researcher from the University of Victoria, British Columbia, to visit these mining sites, to learn first hand about both the economic benefits and environmental consequences of small scale gold mining. Although the name "Kalimantan" means "river of diamonds," it is the promise of gold that has drawn thousands of small scale miners to this region of Borneo over the past decade.

Like millions of small scale miners around the world, these men are irresistibly attracted by the high price of gold, currently around $900 per ounce on the world market. Even if the miners produce only a few grams of gold per day, they can clear about $5 per day, which is about twice the current minimum wage in Central Kalimantan. The gold gives them hope of escape from the intractable poverty that afflicts many, if not most, of the people living on this island.

However, it's astonishing how much land must be cleared, how many tons of soil processed, to extract those few grams, a gold pellet the size of a pea. The miners use water cannons to blast soil from the sides of pits dug into cleared land. The water-soil mixture, or slurry, is pumped down an inclined trough, called a sluice, to separate the heavier particles, including gold, from the rest of the material in the soil. The amount of gold "concentrate" retained in the sluice is tiny compared to the amount of waste material washed away.

The waste material is piled in heaps next to the pits. Once the miners finish with one pit, they move onto another, and then another, and another, leaving a vast, irregular topography of deep pits next to tall waste piles. At just this one site we visited, we calculated that about 4800 hectares (about 50 square kilometers) of land had been disturbed using this practice; I wonder how many more hectares throughout Borneo bear similar scars. Image removed.

The staggering disruption of land and habitat is only one of the environmental problems caused by small scale gold mining; unfortunately for the miners, their families and the rest of the world, the miners use toxic mercury to extract the gold from the "concentrate". Mercury is a neurotoxin that can damage the nervous system; the mercury endangers not only miners and their families, but can also travel around the globe, depositing in the world's waters and poisoning the global fish supply.

I am an anti-mercury warrior, who spends much of my working life fighting against global pollution from this potent toxin; in my next post, I'll describe what it was like to finally meet my nemesis in person.