Gold Mining and Mercury Contamination in the Amazon*

Greed for gold was a pivotal concern in the exploration and colonization of the New World by Europeans, and in the process entire peoples, societies, and environments were degraded and destroyed. This holocaust continues today in the Amazon. Since 1980 the largest gold rush ever developed in the Brazilian Amazon with production at about 100 tons/year exceeding US$2 billion/year, some 4.5 million people involved directly or indirectly, and about 2,000 mining sites scattered over 250,000 km2

Gold mining causes localized deforestation, game depletion and displacement, biodiversity erosion, mercury and other pollution, river and stream bank destruction and siltation, and degradation and decline of fisheries. Enormous amounts of waste result from the mining (nine tons/ounce of gold extracted). Water may be undrinkable for tens of kilometers downstream.

One of the most pernicious and longest lasting consequences of gold mining is contamination with mercury which is the most toxic of metals. Miners introduce 90-120 tons/year of mercury into the ecosystems of the Brazilian Amazon. Miners and buyers are likely to suffer direct contamination with metallic mercury, while the many people in river villages and towns who depend on eating fish as their only alternative for cheap quality protein suffer indirect contamination with the much more dangerous form methylmercury. Mercury contamination of some waters and fisheries could jeopardize the income as well as nutrition and health of masses of people in the Amazon, and the economic loss for commercial fisheries could be enormous. Mercury enters organisms in various ways and is increasingly concentrated at higher levels of the food chain. There are reports of huge fish kills. Migrations of contaminated fish can extend over hundreds or even thousands of kilometers.
Also inorganic mercury can attach to particles of sediments in water courses and be transported by currents over vast distances.

Accumulating research demonstrates widespread and serious levels of mercury contamination of soil, water, sediments, fish and other animals, and people in mining areas and several hundred kilometers downstream in many parts of the Amazon. Gold mining has even contaminated supposedly protected areas, including one of the world's largest wetlands, the Pantanal in Western Mato Grosso.

The health hazards of using mercury have been known since ancient Roman times, and in more recent history from the horrible tragedy of people and animals in the small fishing village of Minamata Bay on Kyushu Island in Japan. Among the many symptoms of chronic poisoning by methylmercury are skin irritations, low fever, headaches, nausea, diarrhoea, fatigue, insomnia and irritability, marked decline in sensory acuity (vision, hearing, smell, touch)
and eventually blindness, loss of ability to speak properly, memory loss, premature senility, manic depression, kidney problems, crippling, severe tremors, brain damage, and death. Pregnant women may be spared from poisoning because the methylmercury rapidly crosses the placenta to accumulate in the fetus which reduces the level in the mother. Still births, spontaneous abortions, gross birth defects, paralysis, physical impairment, and mental retardation are among the abnormalities which result from mercury poisoning of the fetus.

Mining also contributes to the development of other health hazards--- drugs, prostitution (including children), and violence are part of the daily life in mining areas. Syphilis is common and AIDs is increasing. As a highly mobile population the miners are spreading such diseases over a very wide area including to indigenous communities.

There is nothing necessarily inevitable in the degradation and destruction of indigenes and ecosystems through contact with "civilization" and "economic development"; instead this is a "moral" choice of policy makers in government, bank, and corporate offices in Brazil, the U.S.A., and other countries. History provides no reason to hope that the national and provincial governments of the Amazon will suddenly make any profound changes to improve policy and its implementation. The international community must be part of the solution. Gold mining and mercury contamination clearly link human rights and environmental concerns. A systematic campaign is required to inform all levels and sectors of society about the human and environmental hazards of mercury.

The long-term environmental impacts of mercury contamination in local ecosystems, the Amazon basin as a whole, and for the planet are uncertain. Ann Misch in World Watch labels mercury contamination in the Amazon as "... a public health disaster of frightening proportions," while Jed Greer of Greenpeace International observes in The Ecologist: "People in the future will remember this frantic search for bullion because they and the global ecosystem will still be suffering its harmful consequences."
Susanna Hecht and Alexander Cockburn in The Fate of the Forest aptly point out: "Wherever it has occurred, the use of mercury has been associated with human poisoning, and the levels of poisoning that are likely to appear in the Amazon promise to eclipse Bhopal or any comparable case of industrial poisoning. The widespread decentralized scale of mercury contamination of the environment and its inhabitants has no historical precedent."

*This is a summary of Chapter 5 by Leslie E. Sponsel in Life and Death Matters: Human Rights and the Environment at the End of the Millennium, Barbara R. Johnston, ed., 1997, Walnut Creek, CA: Altamira Press, pp. 99-127. (See the full chapter for details, other aspects, and sources).