House Committee Leaders Issue Mercury Report

Published October 1, 2005

House Resources Committee Chairman Richard W. Pombo (R-CA) and Energy and Mineral Resources Subcommittee Chairman Jim Gibbons (R-NV) released on February 16 a detailed report on the science of mercury and the environment, Mercury in Perspective: Fact and Fiction About the Debate Over Mercury.
The paper is a comprehensive synopsis of the peer-reviewed research regarding the debate over regulating mercury. The issue is particularly timely because environmental activists have launched myriad legal challenges to the Bush administration’s proposed mercury cap-and-trade program, the first federal program ever to regulate mercury emissions from power plants.
“Most strikingly, the conclusions drawn in this paper are not drawn by us, but rather by a vast number of scientific and government studies,” said Pombo in an accompanying news release. “We have simply highlighted, in documented fashion, the most important bodies of evidence on this subject. It is clear that research must be continued, and it is very clear that the current knowledge does not support the rhetorical campaigns of special interest groups.”
The following is the first in a series of articles that reproduces, in condensed form, the Pombo-Gibbons report.


In January 2004, the Bush Administration published a draft rule to regulate mercury emissions from coal-fired power plants. According to the Environmental Protection Agency (EPA), power plants currently represent the largest remaining unregulated industrial source of mercury emissions in the U.S. However, it’s important to note that these emissions make up less than one percent of the world’s mercury budget.

The history of the rulemaking is a colorful one that dates back to 1990. The amendments to the federal Clean Air Act (CAA) required a scientific study of whether there was a risk-based need to regulate utility emissions, including mercury.

Former EPA Administrator Browner took eight years under the Clinton Administration to determine a course of action. Finally, on December 14, 2000, two days after Bush v. Gore had been decided by the U.S. Supreme Court, Browner announced that the EPA must issue a mercury emissions rule under Section 112 of the CAA. This decision went against the Clinton Administration’s own Office of Management and Budget (OMB) that recommended a cap and trade approach under Section 111. Even Browner’s “Notice of Regulatory Findings” in the Federal Register recognized cap and trade as an effective control for pollutants and a plausible alternative for reducing mercury emissions.

Browner’s decision delivered an unexpected blow to American utility companies and their customers. Section 112 (d)(3) of the law requires the strictest regulations using Maximum Achievable Control Technology (MACT) standards–technology that some purport can reduce mercury emissions by 90 percent. However, the Department of Energy (DOE) has stated that this is not currently possible for the full spectrum of coals used by American power plants.

The Bush Administration included both options in the proposed rule (the stricter MACT standards and the more flexible cap and trade) issued on January 30, 2004. The Administration’s preferred alternative is the cap and trade program similar to that recommended by Clinton’s OMB and touted as an effective control in the Federal Register by Browner. Nonetheless, national environmental groups now claim the Bush rule falls short of fulfilling the letter of the law.

MoveOn.Org and others ran TV commercials with a similar message and also dubbed the Bush policy a “roll back.” However, given that mercury emissions from power plants will be regulated for the first time ever under the Bush Administration, their claims ring hollow. No President can roll back regulations that don’t currently exist. These groups also falsely assert that the Administration is proposing to allow power plants to release “more mercury into the air.”

As a result of the well-funded effort to push their political agenda, environmentalists have caused American citizens to become unnecessarily concerned about possible adverse health effects from exposure to trace amounts of mercury.

The EPA and Food and Drug Administration (FDA) have stated that for people and animals, the primary means of exposure to mercury is by consuming fish.

Consequently, many people, particularly pregnant women and children, have greatly reduced their fish consumption or have given it up completely.

While these actions seem to constitute a prudent response to information in the public domain, they can contribute to health risks in their own right. Current peer-reviewed research shows that consumption of fish or long chain omega-3 polyunsaturated acids benefits all people from pre-term infants to older adults. Regular fish consumption can reduce the risk of heart attack, contribute to infant eye and brain development, lessen the symptoms of rheumatoid arthritis and may slow the progression of breast and other forms of cancer.

This campaign, which targets coal as the culprit in this “looming” crisis, also serves to exacerbate the nation’s existing energy problems and further burdens the economy. More than 50 percent of the nation’s electricity is generated from coal-fired power plants. Eliminating this abundant, affordable source of energy would cause dramatic increases in energy costs and threaten the closure of some coal-burning plants that supply energy to critical public infrastructure. These effects could very likely contribute to poor health and delayed medical treatment for those members of our society at the lowest income levels–single parents, minorities and those without health insurance.

When a solution to a perceived problem has the potential to create as many or more problems than it resolves, a more thorough evaluation of the issue and associated risks is appropriate. Furthermore, it is impossible to craft and implement good public policy in a climate of fear.

Policy makers should consider, among other things, the fact that air and water quality in the U.S. has dramatically improved. This includes a significant reduction in the use of mercury for industrial and medical applications, and emissions from those applications over the past three decades. Industrial use of mercury in the U.S. has dropped by 80 percent since 1970 and emissions from domestic anthropogenic sources decreased by 40 percent between 1990 and 1996. Additionally, mercury emissions from power plants were reduced by 38 percent from 1995 to 1999. All this occurred with a growing economy and increased energy usage.


Mercury is a naturally occurring element and a part of the Earth’s crust, oceans, and atmosphere. Mercury in rocks and mineral deposits normally occurs as cinnabar, a mercury sulfide (HgS) mineral. Elemental mercury is the unique silver-white metal that is a liquid at room temperature and easily vaporizes.

Most of the mercury existing in the environment is released through natural processes. These natural processes include surface volcanic eruptions; deep sea vents and volcanic activity; hot springs such as the geyser basins in Yellowstone National Park or those at the bottom of Clear Lake in California; evaporation from the ocean basins, other water bodies, and soils; and erosion. The oceans alone contain millions of tons of naturally occurring mercury. Forest fires and the burning of other types of vegetation also contribute to the world mercury budget. These natural “emissions” contribute approximately 61 percent of the annual emissions that make up the world mercury budget.

For example, in Yellowstone National Park, famous for the Old Faithful geyser and other geothermal features, scientists have found high levels of naturally emitted mercury. In the conclusion of their study, the scientists said Yellowstone’s natural mercury emissions may exceed the emissions from all of Wyoming’s eight coal-fired power plants.

However, the presence of mercury in Yellowstone National Park and Lake was said to pose no danger to park rangers, visitors, and even its wildlife. Native grizzly bears who consume up to 400 pounds of cutthroat trout have exhibited no ill effects according to researchers.

Because mercury is a natural part of the Earth’s crust, oceans, and atmosphere and is ubiquitous in the environment, it also occurs in trace amounts in fossil fuels. As a result, when people use fossil fuels such as coal, oil, or gas to generate electricity, mercury is released into the environment.

Other industrial processes such as cement manufacturing, burning of municipal and hazardous waste, medical waste incineration, pulp and paper milling, and mining activities also release mercury into the environment. These human activities combined with power plant emissions in the U.S. make up just 2 percent of the total world mercury emissions.

Current studies of mercury deposition in the U.S. indicate that 70 percent comes from natural sources and non-U.S. anthropogenic emissions. Those non-U.S. anthropogenic emissions mostly originate from China and the rest of Asia. China emits approximately 495 tons of mercury annually from power plants and other sources. It is expected to increase emissions over the next two to five years by 20-30 tons annually due to its rapid economic growth and industrial expansion. The projected annual growth in China’s mercury emissions alone is more than half of the current U.S. power plant emissions in total.

Mercury emissions can behave differently after they are released from power plants depending on the form of mercury. Analyses of emissions from power plants show that about 60 percent occur in the elemental form, which preferentially enters the global atmosphere where it can remain for up to a year or more. The remaining portion occurs in the oxidized (ionic) form, a small portion of which may be deposited locally (within 30 miles).

This is significant since oxidized mercury is water soluble and ultimately available for conversion to an organic mercury compound known as methylmercury. It is this organic form of mercury that is found in trace levels in fish.

Analyses of actual power plant emissions have shown that less than 4 percent of total mercury (elemental and oxidized) is being deposited within 30 miles of the plant.

In general, the majority of the mercury released from power plants is in the non-water soluble elemental form which enters the global mercury pool and is therefore not available for conversion to methylmercury. Emissions from medical, municipal, and hazardous waste incineration plants, on the other hand, release a higher proportion as oxidized (water soluble) mercury into the environment which tends to deposit locally.

Next month: Recent reductions in mercury emissions and advances in emissions-reducing technology.

For more information …

The full text of Mercury in Perspective: Fact and Fiction About the Debate Over Mercury, which will be excerpted in Environment & Climate News, is available online at