One rainy evening in the gold mining city of Segovia in northeastern Colombia, José Leonardo Atehortua was working late at the refinery - or entable - where miners bring their ores to be processed. Atehortua entered the cramped, concrete room and began his labour - roasting balls of amalgam composed of equal parts gold and mercury, an ancient process used to separate one of the world’s most valuable elements from one of the most toxic.
The next thing Atehortua remembers it was morning. He wanted to rise to his feet, to say something, but when he tried to speak saliva poured uncontrollably over his lips and down his chin. He had tunnel vision. He was unable to move his eyes. His limbs were stiff as a plank. He was lying on a cot in the entable surrounded by men saying “José está azogado” - Jose is mercuried.
The mercury poisoning of Atehortua reflects a growing threat in Colombia and other parts of the world as small-scale gold mining expands in response to rising gold prices. Gold and mercury are interdependent commodities. When the price of gold increases - as it has since 2002 - so does mercury pollution. The source of this pollution is a little known but widely practiced variety of small-scale gold mining, found throughout rural districts of the developing world.
To separate precious gold from common stones, small-scale miners cart their ore to town, where it is mixed with mercury in cylindrical mills filled with steel balls that grind the ore into a fine flour. Mercury and gold bind as one, until, sundered by fire, the more volatile mercury is vapourised from the elemental union. The result, in backwater towns like Segovia, can be the exposure of large numbers of people to high levels of mercury vapour, which, in extreme cases like Atehortua’s, can lead to life-threatening mercury poisoning.
The small-scale mining sector, much of it illegal and unregulated, is expanding worldwide faster than at anytime in history and, with it, the health threats posed by mercury. This global gold rush began in Brazil in the late 1970s, before sweeping every mineralised country in South America, Asia, and Africa, with an estimated 15 to 20 million prospectors now active in more than 60 countries.
Today’s small-scale mining industry is motivated less by adventure than survival. Poverty-driven miners rely on inexpensive, outdated, polluting technologies and chemicals - chief among them mercury - with heavy costs for human health and the environment.
Nowhere is this problem of mercury contamination more urgent than in Colombia. Gold mining is Colombia’s fastest growing industry, with 200,000 small-scale miners producing more than 50 per cent of the country’s gold. This growth has turned Colombia into the world’s leading per-capita emitter of mercury, especially in states such as Antioquia, where Segovia is located.
Ground-level concentrations of mercury gas in gold-processing hamlets like Segovia are so high, experts fear the outbreak of an environmental health crisis worse than any caused by mercury since Minamata, Japan, where releases of mercury from a factory in the mid-20th century killed more than 1,700 people. Last year, scientists working for the United Nations Global Mercury Project recorded levels of mercury gas in Segovia’s centre - near public schools and crowded markets - 1,000 times higher than World Health Organization limits.
As Atehortua was being transported to a local clinic, he recalled how nausea and headache had punished him with such intensity the previous night that he had stopped his work to lie down. Unable to be treated at the clinic, Atehortua was sent to the state capital, Medellín, where his blood could be filtered with activated carbon. There the doctors told him to dictate a will. “You are going to die,” they said.
(Atehortua later told his story to Kris Lane, a professor of Latin American history at the College of William & Mary, who interviewed Atehortua in 2008 and 2009 as part of his research for his book on Colombian mining, The Colour of Paradise. Lane relayed Atehortua’s story to me.)
In the ensuing weeks, Atehortua’s molars fell out; he was besieged by ringing in his ears, loss of hearing and appetite, impaired vision and balance, and damaged kidneys - ailments common to acute mercury vapour intoxication. But somehow kidney dialysis worked, and, slowly, movement returned to his arms and legs. Four months later, Atehortua returned to the entable, famous among Segovia’s miners as the azogado who had miraculously recovered from paralysis.
“Unfortunately, people in Segovia say about José Atehortua, ‘Too bad for him, but great story,’ rather than ‘Watch out or this could happen to you,’” says Lane.