Difference between revisions of "Heavy metals and coal"
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| − | {{#badges: CoalSwarm}} Heavy metal refers to any metallic chemical element that has a high density and is toxic or poisonous at low concentrations. Coal contains many heavy metals, as it is created through compressed organic matter containing virtually every element in the periodic table - mainly carbon, but also heavy metals. The heavy metal content of coal varies by coal seam and geographic region. A variety of chemicals (mostly metals) are associated with coal that are either found in the coal directly or in the layers of rock that lie above and between the seams of coal.<ref>Jeff Goodell, Big Coal: The Dirty Secret Behind America's Energy Future. New York, N.Y.: Houghton-Mifflin, 2006</ref><ref name="sludge">[http://www.sludgesafety.org/what_me_worry/heavy_metal.html "Heavy Metals Naturally Present in Coal & Coal Sludge"] Sludge Safety Project, accessed November 2009</ref> The electric power sector is the largest source of toxic pollutants in the United States.<ref>Clean Air Task Force, [http://www.catf.us/publications/view/6 "Laid to Waste: The Dirty Secret of Combustion Waste from America’s Power Plants"], 2000 | + | {{#badges: CoalSwarm}} Heavy metal refers to any metallic chemical element that has a high density and is toxic or poisonous at low concentrations. Coal contains many heavy metals, as it is created through compressed organic matter containing virtually every element in the periodic table - mainly carbon, but also heavy metals. The heavy metal content of coal varies by coal seam and geographic region. A variety of chemicals (mostly metals) are associated with coal that are either found in the coal directly or in the layers of rock that lie above and between the seams of coal.<ref>Jeff Goodell, Big Coal: The Dirty Secret Behind America's Energy Future. New York, N.Y.: Houghton-Mifflin, 2006</ref><ref name="sludge">[http://www.sludgesafety.org/what_me_worry/heavy_metal.html "Heavy Metals Naturally Present in Coal & Coal Sludge"] Sludge Safety Project, accessed November 2009</ref> The electric power sector is the largest source of toxic pollutants in the United States.<ref>Clean Air Task Force, [http://www.catf.us/publications/view/6 "Laid to Waste: The Dirty Secret of Combustion Waste from America’s Power Plants"], 2000</ref> |
Small amounts of heavy metals can be necessary for health, but too much may cause acute or chronic toxicity (poisoning). Many of the heavy metals released in the mining and burning of coal are environmentally and biologically toxic elements, such as lead, mercury, nickel, tin, cadmium, antimony, and arsenic, as well as radio isotopes of thorium and strontium.<ref name="Toppin">Eilene Toppin Ording,[http://environmentalism.suite101.com/article.cfm/heavy_metals_and_coal "Heavy Metals and Coal: Carbon Footprint Aside, Coal is not Environmentally Friendly"] Suite 101, accessed November 2009</ref> | Small amounts of heavy metals can be necessary for health, but too much may cause acute or chronic toxicity (poisoning). Many of the heavy metals released in the mining and burning of coal are environmentally and biologically toxic elements, such as lead, mercury, nickel, tin, cadmium, antimony, and arsenic, as well as radio isotopes of thorium and strontium.<ref name="Toppin">Eilene Toppin Ording,[http://environmentalism.suite101.com/article.cfm/heavy_metals_and_coal "Heavy Metals and Coal: Carbon Footprint Aside, Coal is not Environmentally Friendly"] Suite 101, accessed November 2009</ref> | ||
Revision as of 00:15, 5 December 2009
{{#badges: CoalSwarm}} Heavy metal refers to any metallic chemical element that has a high density and is toxic or poisonous at low concentrations. Coal contains many heavy metals, as it is created through compressed organic matter containing virtually every element in the periodic table - mainly carbon, but also heavy metals. The heavy metal content of coal varies by coal seam and geographic region. A variety of chemicals (mostly metals) are associated with coal that are either found in the coal directly or in the layers of rock that lie above and between the seams of coal.[1][2] The electric power sector is the largest source of toxic pollutants in the United States.[3]
Small amounts of heavy metals can be necessary for health, but too much may cause acute or chronic toxicity (poisoning). Many of the heavy metals released in the mining and burning of coal are environmentally and biologically toxic elements, such as lead, mercury, nickel, tin, cadmium, antimony, and arsenic, as well as radio isotopes of thorium and strontium.[4]
Contents
Coal Ash
Burning coal produces airborne compounds of these elements which settle or wash out of the atmosphere into oceans, streams, and land. Fly ash and bottom ash (collectively referred to as coal ash) are heavily contaminated with the oxides of these heavy metals.[4]
The 1.05 billion tons of coal burned each year in the United States contain 109 tons of mercury, 7884 tons of arsenic, 1167 tons of beryllium, 750 tons of cadmium, 8810 tons of chromium, 9339 tons of nickel, and 2587 tons of selenium. On top of emitting 1.9 billion tons of carbon dioxide each year, coal-fired power plants in the United States also create 120 million tons of toxic waste. That means each of the nation's 500 coal-fired power plants produces an average 240,000 tons of toxic waste each year. A power plant that operates for 40 years will leave behind 9.6 million tons of toxic waste.[5] This coal combustion waste (CCW) constitutes the nation's second largest waste stream after municipal solid waste.[6]
When coal is burned, toxins in the coal are released into the smokestack. With modern air pollution controls, airborne toxins are captured through filtration systems before they can become airborne, and contained in a fine ash called coal ash, fly ash, or coal combustion waste. As a result, heavy metals such as mercury are concentrated in what the EPA considers "recycled air pollution control residue."[7]
Coal ash contains large quantities of toxic metals, including 44 tons of mercury, 4601 tons of arsenic, 970 tons of beryllium, 496 tons of cadmium, 6275 tons of chromium, 6533 tons of nickel, and 1305 tons of selenium.[5] In 2006, coal plants in the United States produced almost 72 million tons of fly ash, up 50 percent since 1993.[7]
Rain falling on coal storage piles and ash piles can leach out these heavy metal compounds into ground water or lakes and streams. Many coal mining states have contaminated drinking water sources due to breaks in liquid coal sludge impoundments.[4]
List of Heavy Metals in Coal
Some of the most commonly found chemicals in coal and coal waste include:[2]
- Aluminum
- Antimony
- Arsenic
- Barium
- Beryllium
- Cadmium
- Calcium
- Chromium
- Cobalt
- Copper
- Iron
- Lead
- Magnesium
- Manganese
- Mercury
- Molybdenum
- Nickel
- Potassium
- Selenium
- Silver
- Sodium
- Strontium
- Tin
- Vanadium
- Zinc
Toxic Effects of Heavy Metals
Small amounts of heavy metals can be necessary for health, but too much may cause acute or chronic toxicity (poisoning). The constant leaching of heavy metals from coal mining and coal plants leads to bioaccumulation in plants and animals, creating the danger of toxicity.[4] Heavy metal toxicity can result in damaged or reduced mental and central nervous function, lower energy levels, and damage to blood composition, lungs, kidneys, liver, and other vital organs. Long-term exposure can result in slowly progressing physical, muscular, and neurological degenerative processes that mimic Alzheimer's disease, Parkinson's disease, muscular dystrophy, and multiple sclerosis. Allergies are not uncommon and repeated long-term contact with some metals may even cause cancer.[8]
Lead
Lead poisoning is possible from too much contact with contaminated soil or drinking water. Lead and mercury affect nervous systems and brain development in children and young animals.[4] Lead accounts for most of the cases of pediatric heavy metal poisoning.[8]
Mercury
Coal-fired power plants are the largest source of mercury in the United States, accounting for about 41 percent (48 tons in 1999) of industrial releases (see Mercury and coal). Tuna and other fish absorb this mercury run-off. According to the Centers for Disease Control and Prevention, eight percent of American women of childbearing age had unsafe levels of mercury in their blood, putting approximately 322,000 newborns at risk of neurological deficits. Mercury exposure also can lead to increase cardiovascular risk in adults.[9] When mercury is deposited on land or in water, microorganisms convert part of it to a highly toxic form called methylmercury. When fish and animals eat these microorganisms, the toxins accumulate and can interfere with reproduction, growth, and behavior, and can even cause death.[10]
Arsenic
Arsenic is the most common cause of acute heavy metal poisoning in adults, and does not leave the body once it enters.[8]
Resources
References
- ↑ Jeff Goodell, Big Coal: The Dirty Secret Behind America's Energy Future. New York, N.Y.: Houghton-Mifflin, 2006
- ↑ Jump up to: 2.0 2.1 "Heavy Metals Naturally Present in Coal & Coal Sludge" Sludge Safety Project, accessed November 2009
- ↑ Clean Air Task Force, "Laid to Waste: The Dirty Secret of Combustion Waste from America’s Power Plants", 2000
- ↑ Jump up to: 4.0 4.1 4.2 4.3 4.4 Eilene Toppin Ording,"Heavy Metals and Coal: Carbon Footprint Aside, Coal is not Environmentally Friendly" Suite 101, accessed November 2009
- ↑ Jump up to: 5.0 5.1 "Green Coal?," Rachel's Environment & Health News, November 6, 2008.
- ↑ Sue Sturgis, "Coal's ticking timebomb: Could disaster strike a coal ash dump near you?," Institute for Southern Studies, January 2009
- ↑ Jump up to: 7.0 7.1 "Fly ash: Culprit at Lafarge? Residue of coal-burning is being examined as possible source of mercury pollution," Times Union, October 26, 2008.
- ↑ Jump up to: 8.0 8.1 8.2 "Heavy Metal Toxicity" Life Extension, accessed November 2009
- ↑ “Mercury Emissions from Coal-Fired Power Plants: The Case for Regulatory Action,” Northeast States for Coordinated Air Use Management, October 2003.
- ↑ "'Fingerprinting' Method Tracks Mercury Emissions From Coal," ScienceDaily, October 9, 2008.
Related SourceWatch articles
- Climate impacts of coal plants
- Mountaintop removal
- Mercury and coal
- Sulfur dioxide and coal
- Global warming
- Environmental impacts of coal
- Coal waste
