Clean Energy - If not now, When?

Sulfur Dioxide Pollution from Power Plants

Sulfur dioxide (SO2) is a highly toxic air contaminant that is formed when fuels containing sulfur, like coal and oil, are burned and released to the air. Once released, SO2 is easily converted to sulfuric acid, which is the major component in acid rain, and to sulfate particles, which contribute to tens of thousands of premature deaths each year. SO2 can be carried in the wind for hundreds of miles and often crosses state and international borders. Sulfuric acid and sulfate particles are extremely harmful to both public health and the environment.

Coal-Burning Power Plants are the Single Largest Source of SO2 Pollution

Power plants are responsible for over 64 percent of the annual total SO2 emitted in the US. (1) In 1998, they emitted over 13 million tons of SO2. (2) While the 1990 Clean Air Act Acid Rain Program (Title IV) made some progress in reducing SO2 emissions from power plants, those emissions are now on the rise. Power plant SO2 emissions increased every year from 1996 through 1998, rising more than 10 percent over 1995 levels. (3) In 1998, power plants emitted 1.26 million more tons of SO2 than they emitted in 1995. (4) Among power plants, the dirty and old coal-fired facilities produce the most pollution. 56 percent of power plant boilers in the US are fueled by coal. (5) However, coal-burning power plants account for more than 96 percent of the SO2 emitted by all power plants. (6)

Clean Air Act Loophole Lets Oldest, Dirtiest Powr Plants Emit More SO2 Than New Facilities

Today the vast majority of coal- and oil-fired power plants have avoided the most protective air emissions standards. When the Clean Air Act was amended in 1970 and 1977, the power industry argued that many of the nation's older power plants would be retired and replaced by cleaner, new power plants and therefore should be exempt from new emission regulations. However, for a variety of reasons, most of these plants have not retired. Because of this grandfathering loophole, coal-fired power plants are largely exempt from modern, state-of-the-art pollution control requirements. The vast majority of these plants fail to meet modern pollution standards for NOx and SO2. This special treatment for grandfathered power plants permits these facilities to pollute at rates up to 10 times that of modern coal plants.

As a result of this "pollution subsidy," the electric industry is relying on its oldest, dirtiest plants more than ever. For instance, from 1992 and 1998, the amount of electricity generated from dirty and old "grandfathered" coal-fired power plants increased by almost 16 percent. (7)

S02 from Power Plants Severly Damages Our Health and Environment

Health Damage

Sulfate particles produced by coal-burning power plants are extremely harmful to human health. Sulfates are the primary component of fine particle pollution in the eastern United States. (8) Fine particle pollution is often referred to as PM2.5 because it consists of particles with a diameter smaller than 2.5 microns.

Sulfates and other fine particles harm people because their tiny size allows them to be inhaled deep into the lungs where they lodge and cause damage. Major health concerns associated with fine particle exposure range from difficult breathing, damage to lung tissue and premature death. US EPA estimates that 15,000 Americans die prematurely each year because of excessive fine particle pollution. (9) Studies put the total annual mortality rate due to fine particle pollution at more than 45,000 premature deaths. (10)

High concentrations of SO2,, such as those recorded in the vicinity of coal-burning power plants, can also result in breathing impairment for asthmatic children, seniors and healthy adults. Asthma sufferers can experience wheezing, chest tightness, and shortness of breath from short-term exposure to SO2. Longer-term exposure at high concentrations can trigger respiratory illness, alterations in the lungs' defenses, and aggravation of existing cardiovascular disease. (11)

Environmental Damage

SO2 reacts in the atmosphere with water, oxygen, and other powerplant pollutants, such as nitrogen oxides (NOx), to form acidic compounds. These acidic compounds return to the earth in the form of acid deposition or "acid rain."

A combination of high deposition and acid sensitive soils and bedrocks makes several regions of the North America particularly vulnerable to acid rain from coal-burning powerplants. The most sensitive sites are located Adirondacks, the mid-Appalachians and portions of southeastern Canada. Highly acidic waterbodies are also found in the Upper Midwest, Florida and New Jersey's Pine Barren.

Aquatic systems are most susceptible to acidic inputs. Acidic deposition increases surface water acidity and the availability of aluminum. These changes, in turn, kill fish and other aquatic life. In Pennsylvania, acid-sensitive fish, including species of trout, have disappeared from streams where they formerly occurred in large numbers. (12) About 50 percent of Virginia's trout streams are "non-acidic" enough to support brook trout — down from an estimated 82 percent of pre-industrial streams. (13) A National Surface Water Survey of over 1,000 lakes and thousands of miles of streams found that acid rain increased acidity in 75 percent of the lakes and about 50 percent of the streams. (14)

In addition to chronic acidity, many lakes and streams become temporarily acidic during heavy downpours and snowmelts. This type of "episodic acidification" causes fish kills and often occurs at times of the year when young fish are most vulnerable.

Acid rain has damaged high-elevation red spruce trees that grow on the ridges of the Appalachian Mountains from Maine to Georgia, including national parks such as the Shenandoah and the Great Smokey Mountains. For example, the U.S. Forest Service has found areas of hardwood mortality in the Southern Appalachians where air quality, especially acid rain, has worked in combination with other stressors to kill the trees. (15) Acid rain also strips away vital plant nutrients, thus posing a threat to future forest productivity.

Acid rain and the dry deposition of acid particles are also known to accelerate the decay of building materials and paints, including irreplaceable buildings, monuments and sculptures that are part of our nation's cultural heritage. Even cars suffer from acid rain. To reduce the damage to automotive paint, manufacturers now use acid-resistant paints at an annual cost of $61million for all new cars and trucks sold in the US. (16)

Finally, sulfate particles from coal-burning powerplants account for more than 50 percent of the visibility reduction in the eastern US, affecting our enjoyment of national parks, such as the Great Smoky Mountains and Acadia. Sulfate particles degrade vistas in many of the western national parks such as Grand Canyon, Canyonlands and Bryce Canyon.

Dirty Power Plants Must be Force to Reduce SO2 Emissions

The serious damage to our health and environment caused by SO2 pollution can be meaningfully reduced only when the Clean Air Act's 30-year grandfather loophole for dirty old power plants is finally closed. Dirty old coal-fired power plants must be made to comply with modern pollution control standards. Closing the loophole and capping power plant emissions at reasonable levels will dramatically reduce SO2 pollution so we can all breath easier.

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1) US EPA, "National Air Quality and Emission Trends Report, 1997" (December 1998), Table A-8, p. 117. Available online at http://www.epa.gov/oar.

2) US EPA, Acid Rain Program, "National SO2 Emissions Trend for all Title IV Affected Units," contained in "Emissions Scorecard 1998." Available online at http://www.epa.gov/acidrain/score98/es1998.htm.

3) Id.

4)Id.

5) US EPA, Acid Rain Program, "National Summary Percent Contribution by Unit Fuel Type." Available online at http://www.epa.gov/acidrain/emissions/us_sum.htm.

6) Id.

7) US PIRG and Environmental Working Group, "Up In Smoke," (Compiled from US Department of Energy (DOE) and USEPA data).

8) US EPA, "Human Health Benefits from Sulfate Reductions Under Title IV of the 1990 Clean Air Act Amendments," (November 10, 1995), p. S-2. Available online at http://www.epa.gov/acidrain. See also National Science and Technology Council, "National Acid Precipitation Assessment Program Biennial Report to Congress: An Integrated Assessment," (May 1998). Available on-line at http://www.nic.noaa.gov/CEN/NAPAP.

9) US EPA OAQPS, 1996 Staff Papers on smog and soot pollution: "Review of the National Ambient Air Quality Standards for Ozone and Particulate Matter."

10) Natural Resources Defense Council, "Breathtaking: Premature Mortality Due to Particulate Air Pollution in 239 American Cities," (1996).

11) US EPA, "National Air Quality and Emission Trends Report, 1997" (December 1998), p. 47.

12) Heard, Robin, William Sharpe , Robert Carline and WG Kimmel. 1997. Episodic acidification and changes in fish diversity in Pennsylvania headwaters streams. Transactions of the American Fisheries Society. 126: 977-984.

13) Bulger, Art, Jack Cosby and Rick Webb. 1998. Acid Rain: Current and Projected Status of Coldwater Fish Communities in the Southeastern US in the Context of Continued Acid Deposition. A Coldwater Conservation Fund Report.

14) US EPA, "Environmental Effects of Acid Rain," (April 1999). Available online at http://www.epa.gov/acidrain/effects/envben.html .

15) US Forest Service data, available online at: http://svinet2.fs.fed.us:80/gwjnf/airpollution.html.

16) US EPA, "Environmental Effects of Acid Rain," (April 1999). Available online at http://www.epa.gov/acidrain/effects/envben.html .