NTAA: Air Topics

NTAA Air Topics:

Mercury Articles

EPA Sets Date for Public Hearing on Mercury Toxics Rule

EPA Proposes New Source Provisions for MATS

EPA to Propose New Source MACT by November 20, 2012

EPA Pushes Back on Calls for Revised MATS Timeline

Challengers Outline Arguments Against EPA Mercury Rule

Mercury Overview

Forms of mercury. 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.
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Sources of mercury. Mercury is an element in the earth's crust. Humans cannot create or destroy mercury. Pure mercury is a liquid metal, sometimes referred to as quicksilver that volatizes readily. It has traditionally been used to make products like thermometers, switches, and some light bulbs.

Mercury is found in many rocks including coal. When coal is burned, mercury is released into the environment. Coal-burning power plants are the largest human-caused source of mercury emissions to the air in the United States, accounting for over 50 percent of all domestic human-caused mercury emissions (Source: 2005 National Emissions Inventory). EPA has estimated that about one quarter of U.S. emissions from coal-burning power plants are deposited within the contiguous U.S. and the remainder enters the global cycle. Burning hazardous wastes, producing chlorine, breaking mercury products, and spilling mercury, as well as the improper treatment and disposal of products or wastes containing mercury, can also release it into the environment. Current estimates are that less than half of all mercury deposition within the U.S. comes from U.S. sources.
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Sources of mercury compounds. In the U.S., mercury compounds are manufactured in small amounts for specialty uses, such as chemical and pharmaceutical applications. Larger quantities of these compounds are generated as byproducts from pollution control activities at gold mines or in waste. Elemental mercury is processed in the U.S. from byproduct mercury compounds, and an unknown quantity of mercury compounds is imported into the United States for conversion to elemental mercury.
Learn more about mercury compounds (PDF). (123 pp, 738K, About PDF)

Exposure to mercury. Mercury in the air eventually settles into water or onto land where it can be washed into water. Once deposited, certain microorganisms can change it into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish. Fish and shellfish are the main sources of methylmercury exposure to humans. Methylmercury builds up more in some types of fish and shellfish than others. The levels of methylmercury in fish and shellfish depend on what they eat, how long they live and how high they are in the food chain.

EPA works with the U.S. Food and Drug Administration (FDA) and with states and tribes to issue advice to women who may become pregnant, pregnant women, nursing mothers and parents of young children about how often they should eat certain types of commercially-caught fish and shellfish. Fish advisories are also issued for men, women, and children of all ages when appropriate. In addition, EPA releases an annual summary of information on locally-issued fish advisories and safe-eating guidelines to the public. Fish is a beneficial part of the diet, so EPA & FDA encourage people to continue to eat fish that are low in methylmercury.
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Another less common exposure to mercury that can be a concern is breathing mercury vapor. These exposures can occur when elemental mercury or products that contain elemental mercury break and release mercury to the air, particularly in warm or poorly-ventilated indoor spaces.
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Health effects of mercury. 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.
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Ecological effects of mercury. 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.
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Reducing mercury releases. EPA issues regulations that require industry to reduce mercury releases to air and water and to properly treat and dispose of mercury wastes. In 2010, EPA is working to develop emissions standards for power plants under Clean Air Act section 112, consistent with the D.C. Circuit’s February 2008 opinion regarding the Clean Air Mercury Rule (CAMR). On October 6, 2009, EPA published a final rule that limits emissions, including emissions of mercury, from medical waste incinerators.

EPA works with partners in state, local and tribal governments to implement a variety of programs designed to reduce mercury pollution and impacts. Most of EPA's environmental regulations and programs are implemented by the states. In addition, under U.S. environmental laws, the states are often permitted to adopt local environmental laws and regulations that are more stringent than federal requirements. As of 2005, twenty- two states were implementing or developing overall state-based mercury action plans. Many of the state plans include pollution reduction elements that exceed federal requirements. In particular, the states in the Great Lakes basin and northeast region have led efforts to identify and pursue ways to reduce and prevent mercury releases to the environment, both as individual states and in multi-state collaborations.

EPA also works with industry to promote voluntary reductions in mercury use and releases. In December 2008, EPA, the ADA and the NACWA signed a Memorandum of Understanding to establish a Voluntary Dental Amalgam Discharge Reduction Program. The goal of the program is for dentists to follow the ADA’s best management practices (BMPs) for amalgam waste.

EPA works with international organizations to prevent the release of mercury in other countries. EPA has provided expertise to the United Nations Industrial Development Organization (UNIDO)'s Global Mercury Project's small-scale gold (artisanal) mining project, which focuses on best management practices to reduce occupational exposures, emissions and mercury use. Learn more about EPA's international activities.

The public can contribute to mercury reduction efforts by correctly disposing of products that contain mercury. Learn more about consumer and commercial products that contain mercury.

For more information, see answers to frequent questions about mercury.

For more information,
see answers to frequent questions about mercury.

Significance to Tribes

A common mission of tribal air programs is to preserve and protect the culture, ecosystems and public health of the tribal communities. From a tribal perspective, preservation of a tribe’s culture through improved air quality is just as vital as improved public health. In many cases a tribe’s culture is directly linked to their environment. Therefore, poor air quality results in the potential for tribal culture to degrade. An example of this can be found in tribes whose cultural identity is tied to subsistence fishing. Most fresh water sources are polluted with mercury and other toxins so that it is no longer safe to consume subsistence levels of fish. The loss of consumable fish due to bioaccumulation of mercury from air pollution is a good example of a tribe’s culture being impacted by air quality. Nationally, 55.4% of tribal populations lives within 50 miles of major mercury sources.

Mercury is an air toxic pollutant that is of particular concern to tribes. Mercury consumption is a health concern among those tribes whose traditional diets include large amounts of fish, waterfowl, medicinal plants, moose and other land animals. Such diets have not been adequately considered by the USEPA in the process of addressing emissions standards for mercury. For example, in developing its recent rule for mercury emissions from power plants, EPA considered two segments of the population to be relevant to its analysis: recreational anglers, and "high level" consumers such as some Native American and other ethnic populations. In calculating the risk to these groups, USEPA used maximum fish consumption levels of 25 g/day for anglers and 170 g/day for high consumers. However, even this "high level" number may be far from adequate for some tribal populations. For example, a survey of Great Lakes area tribes produced a range of 189.6 to 393.8 g/day, and the Minnesota Chippewa Tribe has adopted 227 g/day as its treaty protected subsistence quantity. Many tribes are in the midst of assessments of mercury levels in their water, fish, and wildlife. In general, however, there is marked absence of mercury deposition data in the western U.S., where the majority of the tribal land base exists. Because dry deposition monitoring techniques are not as developed as wet deposition techniques, data is particularly lacking in the southwest, where dry deposition predominates. Acquiring more deposition and health effects data is a priority for tribes in the years to come. Other toxics of concern include residential wood smoke, diesel emissions, and sources that are off reservation.

NTAA Documents

NTAA Analysis - Proposed Mercury Federal Implementation Plan under the CAMR (April 16, 2007)

NTAA Comment Letter "Regarding EPA’s 'Reconsideration of Rule Revising Earlier Regulatory Finding and Removing Certain Electric Steam Generating Units From the List of Source Categories'" (December 19, 2005)

NTAA comments on Proposed Rule for the Utility Mercury Reductions (June 22, 2004)

Related Documents

EPA Letter to Senator Wyden re: the 2011 Boiler Air Toxics Rule (Jan 18 2002)

EPA Presentation - Gold Mines Development of Proposed MACT rule for Mercury Emissions (February 11, 2010)

US PIRG "Milestones in EPA Mercury RulemakingDecember 2003 - August 2005" (August 17, 2005)

Research Paper: "Fishing for Identity: Mercury Contamination and Fish Consumption Among Indigenous Groups in the United States" Amy Roe, University of Delaware (October 2003)


"Mercury Emission Sources, Mercury Monitors and Their Relation to Tribal Lands of the United States" Source: ITEP

Related Links

10 Proposed Coal Fired Power Plants Raise a Host of Issues for Tribes in Michigan Area - Robin Clark, Inter-Tribal Council of Michigan ( opiichii@gmail.com) (March 12, 2010)

USA Today - "Tribal Ways Threatened By Rising Mercury Levels." - October 30, 2007

Mercury Deposition Network (MDN) - the only network providing a longterm record of total mercury (Hg) concentration and deposition in precipitation in the United States and Canada.