If you take a look at your hands, your wrists, or your neck, you will likely see something special, precious even. It is quite dense, glows with an almost aura-like quality, and, as of press time, costs about $1,350 an ounce. The material – gold – is familiar to all of us. Less known, however, is how it gets to us and the role of another unique metal in that process. Liquid Mercury, a toxic substance that has been phased out of equipment and processes in the US over many years, is essential to artisanal gold mining in much of the world.
On October 16th, Luis Fernandez the director of the Carnegie Amazon Mercury Ecosystem Project visited Wake Forest for a lecture on the use of mercury in artisanal, or manual gold mining and its impacts on the environment and people of the Madre de Dios region of Peru. Madre de Dios is a region of eastern Peru extending into the Amazon basin and is marked by some of the most intensive artisanal gold mining activity in South America.
The process of gold mining in the Amazon is much as it was a few hundred years ago here in the US. Water cannons are used to wash away the topsoil from small areas of forest, a few hundred feet square. This leads to extensive deforestation; a new study from Greg Asner, also with the Carnegie Institute, determined that over 120,000 acres have been deforested for gold mining in Madre de Dios and small artisanal mines have become the main culprit. After removing the vegetation and topsoil, the pay dirt is then washed through equipment to separate the gold by gravity. The problem with the pay dirt in Peru, and other areas where artisanal gold mining is common, is that the gold is present only in small flakes, not the stereotypical nuggets. So, miners use mercury to bind the small flakes of gold and concentrate them, separating the gold from other sediments. In the end, the mercury is burned off, releasing it into the atmosphere and environment. This mercury finds its way into soil and rivers, where it is slowly accumulated in crops and fish, contaminating some of the only reliable sources of food in the region.
Fernandez’s research focuses on identification of mercury contamination in fish and people in the region and his latest work has produced alarming information: over 60% of fish sold in markets in Puerto Maldonado, the capital of Madre de Dios, are contaminated with dangerous levels of mercury and 78% of people in Puerto Maldonado had unsafe levels of mercury in their bodies. Even worse, the most vulnerable population, women of childbearing age, had the highest mercury levels at 3 times the safe amount.
So, with all this bad news we ask ourselves, what can be done? What are the long-term effects on these populations? What are the long-term effects on the environment? Can the contaminated areas be reforested and, if so, how can it be done? Can the demand for gold be reduced so that it is not profitable for these small-scale, mostly illegal operations to persist? The answers to many of these questions are still unknown. There are currently few identified major health effects due to the low but chronic exposure to mercury, but cryptic effects such as decreased intelligence in children are being identified. Methods of removing mercury from the environment on a large scale are in their infancy and the gold mines are small but spread across a vast area, further complicating restoration efforts. What is known, however, is that if consumers demand safely and responsibly mined gold, as has been done with diamonds, or if they simply demand less gold, artisanal gold mining activity and the damage it causes will fade.
Banner photo courtesy of Sprout Money, via Flickr Creative Commons