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Smart Planet

Silver: The harsh realities behind diminshing supplies

About the author

Gaia is a science writer and broadcaster who is particularly interested in how humans are transforming planet Earth and the impacts our changes are having on societies and on other species. She has visited people and places around the world in a quest to understand how we are adapting to environmental change. You can follow her adventures at www.WanderingGaia.com and on Twitter at @WanderingGaia.

 

  • Silver dreams
    Towering over the town of Potosi, Bolivia, Cerro Rico was once one of the largest silver deposits in the world. (Copyright: Getty Images)
  • Prosperous past
    Potosi was founded in 1545 on the basis of its silver – in its heyday, the city was bigger than London or Paris. (Copyright: Nick Pattinson)
  • Raw material
    A miner holds a piece of raw silver, a sight that will become increasingly rare over the next few decades. (Copyright: Getty Images)
  • Cramped conditions
    Workers in the Cerro Rico mines work under stifling, confined conditions for hours on end, and die on average before the age of 35. (Copyright: Getty Images)
  • Teen labour
    A census in 2001 showed that 381 minors of both sexes between 7 and 18 years old worked in the Cerro Rico mines. (Copyright: Getty Images)
  • Protective forces
    Miners are extremely superstitious – this god of the mines is covered in offerings to appease him and spare the miners lives. (Copyright: Nick Pattinson)
  • Rare respite
    Young miners enjoying a break outside one of the mines at Cerro Rico hill. (Copyright: Nick Pattinson)
  • Mineral collectors
    One of 120 women who hammer rocks at Cerro Rico to extract silver, tin and zinc residues, for which they receive around 1.5 US dollars per day. (Copyright: Getty Images)

HIDE CAPTION

Our columnist discovers first hand the conditions people at a Bolivian mine are still enduring to mine rapidly dwindling supplies of the precious metal.

At over 4,000 metres above sea level, Potosí in Bolivia is the world’s highest city. But it is overshadowed by the rainbow-coloured Cerro Rico, or Rich Hill, which looms above the citizens – an imposing reminder of the cause of the city’s splendour and horror. The city was founded in 1545 following the discovery of silver in the Cerro Rico, the veins of which proved to be the world’s most lucrative, bankrolling the Spanish Empire for more than two centuries.

Many roads lead to hell, and I follow a miner to the Candelaria Bajo mine, one of the oldest of the 700 mines in Cerro Rico, which dates back at least 350 years. Like the millions who have gone before me, I take a last look at the sun and then enter the underworld through a low, dark entrance, stained black with llama blood, the remnants of a sacrifice to the devil. Miners are extremely superstitious.

It is no wonder. Cerro Rico held extraordinary quantities of the precious metal – it is said that at one time you could have built a silver bridge from Potosí to Spain and still have enough silver to carry across it – but this came at a terrible cost. Eight million workers died during the 350 years of Spanish occupation. And by the 1800s, the silver was depleted and its global price diminished, sending the city into a decline that it is only recently recovering from, thanks to the demand for tin, lead and zinc.

Short supply

Cerro Rico is emblematic of a wider malaise. Global reserves of silver are diminishing rapidly, and supplies could run out as soon as 2029. That is, if we consume silver at the rate we are today and no new deposits are found, according to Mansoor Barati, a metals production and refinery expert at the University of Toronto. The reality is that rising silver prices will make exploration become more cost-effective and new deposits are likely to be found, but even then Barati’s prognosis is grim. "Silver will last longer,” he says, “but not beyond this century."

As it becomes scarcer, the price of silver has rocketed up, from less than $5 an ounce in 2000 to $48 in April 2011 (currently, it is fetching around $32 an ounce). So Cerro Rico still draws silver miners into its black heart, killing them on average before the age of 35 – from silicosis, mesothelioma, accidents, and poisonings from the various noxious chemicals they are exposed to, including cyanide, mercury and carbon monoxide.

The air I breathe when I enter the dark and dusty mine is infused with a peculiar smell – a caustic combination of the many chemicals here. I stumble along, crouching under the low rocks, trying to forget that 10 years ago geologists predicted that the mountain, riddled with tunnels and crevices, would collapse within 8-10 years. I bash my head frequently, alternatively grateful for my hard hat and cursing it for falling down over my eyes and obscuring my view of obstacles. I struggle to mount a rock just in time as a series of steel trollies come speeding down the tracks towards us, pushed and pulled by ghostly men, wide-eyed from coca.

The air becomes impossible to breathe through my scarf as I continue deeper and further into the mine, and it becomes harder to see with every step. Soon I am reduced to crawling on hands and knees through tunnels tight enough to panic in, and still we descend.

Sliding down a hole we reach a lower level, where workers with mad staring eyes push and pull trolleys laden with tonnes of rock past us, seemingly not noticing our presence. I am a couple of kilometres inside the mountain now and it is stiflingly hot, lung-searingly difficult to breathe and incredibly exhausting – and I am not even working.

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