Canadian mining operations in Canada and abroad do not use mercury and,
where mercury is naturally present in ores, take precautions to prevent its
release into the environment. Mercury use by the artisanal and small-scale
mining sector is a growing environmental concern in developing nations.
Humans have mined mercury since the Roman times and it is still used in
products such as fluorescent lights, energy saving lamps, and electronic devices.[1,
p.12] Mercury is also a by-product from the mining and refining of other metals
including gold, silver and zinc [2, p.117] although most of this can be captured
and reused.[1, p. 11]
Mercury was once used throughout the world in gold processing. It was employed
to assist with the extraction of gold and silver from ore. This process has
since been replaced by more efficient and less environmentally damaging techniques
such as cyanide leaching in large-scale and industrial mining.
In developing nations, mercury pollution is increasingly a result of illegal
or artisanal mining and is an ongoing and growing concern.
Mercury is highly toxic and can cause serious illness and death in humans
and animals. Globally, for health and environmental reasons, efforts are being
made to reduce the use and release of mercury.
Mercury---also known as quicksilver--is an element found in nature in various
forms. It is released into the environment through natural processes such
as volcanic eruptions, the weathering of rocks, and forest fires.[2, p.11]
Mercury is also released through human activities and industrial processes.
Because it is an element, mercury does not break down in the environment.
Instead, it is cycled between the atmosphere, land, and water, and can travel
large distances from the original source[2, p.110]. Mercury can also build
up in humans and animals and become highly concentrated in the food chain.
This is a problem since low levels of mercury exposure can build up over time
until concentrations are high enough to be harmful.
Mercury is still used to extract gold in the developing world despite safer
alternatives and the elimination of mercury use by large-scale mining operations.
It is used by artisanal
and small-scale miners (ASM), often in unsafe and environmentally damaging
ways.[1, p.13] The United Nations Industrial Development Organization estimates
that 1,000 tons of mercury is released into the air, soil, and water each
year by this sector.[4, p.9]
Mercury is used to purify gold from ore in a process called amalgamation.
Miners and their families often inhale toxic mercury vapors through this process,
and mercury can pollute homes and communities. It can also contaminate
the land and water where gold processing occurs.
Global initiatives such as the UN-led Global Mercury Project are trying
to help miners in developing countries adopt best practices and reduce mining
pollution caused by the use of mercury. Members of the International Council
on Mining & Metals (ICMM) have also committed to promote the responsible
use of mercury and partner with governments to transfer low- or no-mercury
processing technologies to the ASM sector.
1UNEP Chemicals Branch, The Global
Atmospheric Mercury Assessment: Sources, Emissions and Transport, 2008,
UNEP-Chemicals. 2UNEP Chemicals Branch, Global Mercury Assessment, 2002,
UNEP Chemicals. 3Canada, Environment Canada. About Mercury. 2010 March
25, 2010 [cited 2011 October 31]; Available from: http://www.ec.gc.ca/mercure-mercury/default.asp?lang=En&n=D64997D2-1. 4Communities and Small-Scale Mining (CASM), International Finance
Corporation‘s Oil, Gas and Mining Sustainable Community Development Fund (IFC
CommDev), and International Council on Mining & Metals [ICMM], Working
together: how large-scale miners can engage with artisanal and small-scale
miners, 2009, ICMM: www.icmm.org. 5Siegel, S. Threat of Mercury Poisoning Rises with Gold Mining
Boom. Yale Environment 360, 2011. 6International Council on Mining & Metals [ICMM], Mercury
Risk Management:Position Statement February 2009, 2009.
While mining has historically affected its surrounding environment, advances in technology and changes in management techniques mean that many negative impacts are now avoidable. Increasingly, mining companies are making efforts to reduce the environmental impact of mining and minimize the footprint of their activities throughout the mining cycle, including working to restore ecosystems post-mining.
This page will explore the issues surrounding mining and the environment and answer common questions.
Artisanal Gold Council (2011). Artisanal and Small Scale Gold Mining: a profitable transition away from mercury use.
Link to page and download
GreenFacts. (2011). Scientific Facts on Mercury
Global Mercury Project. About the GMP
United Nations Environment Program. (2002). Global Mercury Assessment
Human Rights Watch (2011).A Poisonous Mix: Child Labor, Mercury, and Artisanal Gold Mining in Mali.
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