Mining

Mining & Mercury
Mercury risks and implications
What is being done?
Further Reading

Introduction

While coal-fired power plants and their mercury emissions have received much attention in the past, little notice has been paid to gold mines and their role as the fifth largest source of mercury air emissions in the United States. In the state of Nevada, the largest producer of gold in the United States and third largest in the world, gold mining has come under increasing scrutiny in the last several years. It is finally coming to light that the gold mining process releases high levels of the neurotoxin mercury into the atmosphere, carrying serious environmental implications and health risks. Surrounding communities and downwind communities in states such as Utah and Idaho are affected by airborne mercury, which contaminates lakes and wildlife. Because of these serious problems, many in those states and in Nevada are calling for tougher mercury emission controls. As mining companies begin to realize that failure to reduce mercury emissions may hurt their own market position, many are beginning to voluntarily implement tougher controls and state agencies have also recently adopted a tougher stance on the issue. Environmental watchdog groups such as the Great Basin Mine Watch, claim, however, that still more can be done to address the problem.

Quick Facts

Gold mines in Nevada produce 25% of all the mercury air emissions west of Texas
Nationwide, mining contributes 9% of all mercury air pollution. 92% of these emissions are released from four major mining operations in the state of Nevada, making it the state with the second highest emissions of airborne mercury nationwide
The four major mining operations in the state of Nevada – Newmont, Barrick, Placer Dome and Queenstake – comprised about 80% of total Nevada gold production in 2003

Sources: Boulanger, Aimee and Alexanda Gorman. “Hardrock Mining: Risks to Community Health.” Women’s Voices for the Earth. September 2004 at http://www.earthworksaction.org /pubs/MiningHealthReport_WVE.pdf; Nevada Bureau of Mines and Geology, 2003

Gold Mining in Nevada

In Nevada, gold mining is a vital industry and a major contributor to the state’s revenue. Not only does Nevada gold production account for 87% of the total amount of gold produced in the United States, but it also ranks third in the world behind South Africa and Australia. In the rural areas of central and northern Nevada, where the majority of Nevada’s mines are located, mining is the largest industry, employing thousands in otherwise economically bereft regions.

Contributing to the growth and success of the gold mining industry in Nevada, the state is proclaimed to have exceptional conditions for open-pit mining (a technique of modern hardrock mining), and the political atmosphere, state regulations and tax policy have long been favorable to mining. Mining has, furthermore, enjoyed much freedom from the 1872 Mining Law, which is still the primary federal legislation governing mining in the United States. According to this law, speculators are allowed to stake and develop hardrock mining claims on public lands with relatively little regulatory oversight, and no regulatory payment to the government on minerals extracted is required. For years, federal land managers have interpreted this law as forbidding them from denying any corporation the right to mine hardrock minerals on America’s public lands.

Sources: Nevada Mining Association at http://www.nevadamining.org/education /mining_nevada/; Rake, Launce. “Heavy Price For Gold.” Las Vegas Sun. March 5, 2006 at http://www.greatbasinminewatch.org/mambo/index.php?
option=com_content&task=view&id=68&Itemid=81; Boulanger/Gorman 2004

Hardrock Mining and Mercury Emissions

The emission of mercury into the atmosphere is a byproduct of the process of modern gold mining, which is also referred to as hardrock mining. Hardrock mining, the extraction of minerals such as gold, silver, lead, copper and uranium (hardrock minerals) from the earth, is practiced in a manner that can pose serious threats to human health – especially since hardrock minerals are the most loosely regulated natural resources in U.S. mining. Up until recently, relatively few studies have looked at hardrock mining’s greater ecological effects and its effects on people living near, downstream or downwind from mines, however, this trend is slowly being reversed.

Modern gold mining, or hardrock mining, entails crushing many tons of rock in order to obtain the ore containing the precious metal. It is not uncommon for a modern gold mine to extract 60 tons of rock to yield just one ounce of gold. However, the ore that contains gold flakes also contains mercury, so the crushed rock containing the gold must be processed to further extract the mineral. To separate the mercury from the gold, the ore is heated to extremely high temperatures in a process called smelting. Because mercury is more volatile than other materials (it evaporates quickly), it is burned off into the atmosphere, while gold or other metals remain. Airborne mercury is then carried to surrounding communities or is swept downwind to other communities – some even far beyond Nevada’s borders. Scientists have reported that airborne mercury is carried downwind to Idaho, Utah, Colorado, Wyoming and perhaps other states. In one lake near Twin Falls, Idaho, for example, researchers found mercury levels at 150 times more than those found in lakes in the northeast United States, where environmentalists have concerns about mercury from power plants. In Utah, U.S. Geological Survey researchers found mercury concentrations in the Great Salt Lake to be among the highest recorded in surface water.

Sources: Boulanger/Gorman 2004; Earthworks Factsheet. “Mercury Emissions at Gold Mines” at http://www.earthworksaction.org/pubs/FS_Mercury.pdf; Rake 2006

Mercury and the Implications of Exposure

Mercury is a naturally occurring element that is found in air, water and soil. It exists in several forms: elemental or metallic mercury, inorganic mercury compounds, and organic mercury compounds. Airborne mercury eventually settles into water or onto land, either through dry or wet deposition (rain or snow), where it can be washed into water. Once deposited, certain microorganisms in soils and sediments can change it into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish. When animals higher up the food chain eat the smaller ones, they also take in the methylmercury. As this process, (known as bioaccumulation), continues, levels of methylmercury increase up the food chain. Fish and shellfish, however, are the main sources of methylmercury exposure to humans.

Source: U.S. Environmental Protection Agency’s mercury website at http://www.epa. gov/mercury/index.html

Health Risks Associated with Mercury Exposure

Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system of people of all ages. Research shows that most people's fish consumption does not cause a health concern. However, it has been demonstrated that high levels of methylmercury in the bloodstream of unborn babies and young children may harm the developing nervous system, making the child less able to think and learn. Impacts on cognitive thinking, memory, attention, language, and fine motor and visual spatial skills have been seen in children exposed to methylmercury in the womb.

Source: U.S. Environmental Protection Agency’s mercury website at http://www.epa. gov/mercury/index.html

Environmental Risks Associated with Mercury Contamination

The Smithsonian Environmental Research Center found that less than a teaspoon of mercury can contaminate a 22-acre lake and that, in the process of bioaccumulation, fish can amass up to 1 million times as much mercury in their bodies as the water from which they came. Birds and mammals that eat fish are more exposed to mercury than other animals in water ecosystems. Similarly, predators that eat fish-eating animals may be highly exposed. At high levels of exposure, methylmercury's harmful effects on these animals include death, reduced reproduction, slower growth and development, and abnormal behavior.

Sources: U.S. Environmental Protection Agency’s mercury website at http://www.epa. gov/mercury/index.html; Larsen, Kristin. “Group Calls for Scrutiny of Mercury Emissions.” Reno Gazette Journal. January 3, 2007 at http://news.rgj.com/apps/pbcs.dll/article?AID=/20070103 /NEWS07/701030339/1002/NEWS

Why Has the Issue of Airborne Mercury Received So Little Attention?

Up until recently, little attention has been paid to the role of gold mines as a large source of mercury emissions. Before the U.S. Environmental Protection Agency (EPA) took preliminary steps to regulate the metal mining industry in 1998, the amount of mercury released into the atmosphere from gold mining activities had not been systematically measured and reported, and reliable estimates from this sector were unavailable. This means that for decades, gold mining operations in Nevada have pumped out airborne mercury, unregulated by state or federal agencies. It is estimated that Nevada gold mines have produced up to100 tons of mercury over the past 25 years.

The lack of public awareness is largely due to the fact that the mining industry operates out of sight and out of mind of most citizens and the media. For the most part, hardrock mining is concentrated in sparsely populated western states and the vast majority of hardrock mines are located in remote areas, where the impacts are less visible to the majority of the population. Exacerbating the lack of public awareness is the fact that documented threats have been downplayed in the past by pro-industry western politicians, who have been the recipients of mining’s political contributions, and who have worked to keep mercury emissions from mines unregulated.

Sources: Rake 2006; Boulanger/Gorman 2004

See also:

“Nevada Regulators accused of bowing to gold mining industry”
www.rgj.com/news/stories/html/2003/08/08/48895.php

“Mining Industry Worried New Democratic Controlled Congress will be Hostile to Mining”
http://www.lasvegassun.com/sunbin/stories/nevada/
2006/dec/08/120810940.html

What Has and is Being Done to Address the Problem?

In 1997 the U.S. Environmental Protection Agency (EPA) required the metal mining industry to report chemical releases in the Toxic Release Inventory (TRI), beginning in 1998. The first report came out in 2000 – based on 1998 numbers – and revealed that of more than 18,000 pounds of mercury poured from smokestacks into America's skies, all but 5,000 pounds of it came from Nevada, mostly from gold mines. As public awareness of the damage outside of Nevada slowly grew in the years following the first report, the state instituted a voluntary program to cut mercury emissions. The four biggest companies with the largest emissions (Newmont, Barrick, Placer Dome and Queenstake) and the Nevada Environmental Protection Division quickly drafted and enacted the Voluntary Mercury Reduction Program in 2001. The EPA says the program has sliced emissions by 80 percent, although environmentalists and officials in neighboring states challenge that claim.

As of May 6, 2006 Nevada precious metal mines were required for the first time to measure and report mercury released from smokestacks to the Nevada Department of Environmental Protection under the Mercury Air Emissions Control Program for precious metal mining. Nevada is the only state with such a requirement. While the U.S. EPA only requires an estimation process, the new Nevada regulation requires mining companies to use measurements taken directly from the smokestack. The new law makes obtaining a permit and continued operation contingent upon:

1) Adequate testing and record-keeping, verified during annual state on-site inspections
2) Installation of emissions-reducing technology in 3-5 yrs
3) Annual testing of smokestack emissions by independent contractors, whose methods must be evaluated and approved by state
4) A penalty for non-compliance

Sources: Boulanger/Gorman 2004; Nevada Division of Environmental Protection Mercury- Laws and Regulations http://ndep.nv.gov/mercury/regulation6.htm; Larsen 2007

Can More be Done?

Responding to the new 2006 requirements, watchdog group Great Basin Mine Watch said the law does not go far enough. The group wants testing done by the state, more frequent testing of mine smokestacks and measurement of the amount of mercury in communities near mines. At issue is the problem of underreporting or inaccurate monitoring in the past, as emissions were projected by computer, based on measures taken years ago. The group cites a Nevada-based gold mine that reported incorrect releases from 2001 to 2005 before correcting the numbers. For this reason, the group asserts that local, state and federal agencies need to more closely monitor the mercury emissions of precious metal mines.

In Hardrock Mining: Risks to Community Health (2004) authors Aimee Boulanger and Alexanda Gorman assert that other steps must also be taken to address the problem of mercury contamination from gold mines:

1) More financial resources must be provided to expose mining’s impacts on human health
2) Regulatory agencies must be required to fully establish the risks associated with proposed new mines
3) Regulatory agencies must be required to monitor pollutants that threaten health from current and proposed mines
4) Local communities must be involved in the permitting and oversight of the industries directly impacting their communities

Sources: Rake 2007; Boulanger/Gorman 2004

Links/Literature

Great Basin Mine Watch is a coalition of environmental, Native American and scientific community representatives with a mission to protect the land, air, water and wildlife and the communities that depend on them from the adverse impacts of mining
http://www.greatbasinminewatch.org/mambo/index.php

U.S. Environmental Protection Agency website is general but extensive mercury knowledge resource
http://www.epa.gov/mercury/index.html

Nevada Division of Environmental Protection. Mercury Web Site http://ndep.nv.gov/mercury/index.htm

Mercury Reductions Database provides information about mercury reduction programs across the nation
http://www.p2rx.org/Networking/MercuryDB.cfm

The EARTHWORKS partnership teams with local, state/regional and national partners to support local communities, monitor the mining industry, and proactively promote reforms in mining practices.
http://www.earthworksaction.org/us_program.cfm

Boulanger, Aimee and Alexanda Gorman. “Hardrock Mining: Risks to Community Health. Women’s Voices for the Earth.” September 2004. Report addresses the gap in scientific study and public information regarding risks for people living near modern mines.
http://www.earthworksaction.org/pubs/MiningHealthReport_WVE.pdf

The Toxics Release Inventory (TRI) is a database containing detailed information on nearly 650 chemicals and chemical categories that over 23,000 industrial and federal facilities manage through disposal or other releases, and waste management for recycling, energy recovery, or treatment. This inventory was established under the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA) and expanded by the Pollution Prevention Act of 1990.

For Reporting Year 2005, 23,461 facilities reported to EPA’s TRI Program. These facilities reported 4.34 billion pounds of on-site and off-site disposal or other releases of the almost 650 toxic chemicals. Over 88 percent of the total was disposed of or otherwise released on-site; almost 12 percent was sent off-site for disposal or other releases. Nevada TRI Fact Sheet

Trasande, Leonardo et al. “Public Health and Economic Consequences of Methylmercury Toxicity to the Developing Brain.” February 2005

Van Zyl, D.J.A. and G.M. Eurick, “The Management of Mercury in the Modern Gold Mining Industry” EPA Conference Proceedings on Mercury in the Environment, 2001.