The following Material Health Risk Profiles are compiled from EPA and industry studies, as well as from information available in EPA chemical databases.

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ARSENIC

What is arsenic?
Arsenic (As) is a gray, brittle, semi-metal that tarnishes in air. It is a natural component of the earth’s crust and occurs in small amounts in bodies of water, underwater sediments, and soils. It is commonly found in combination with sulfur and iron in minerals such as pyrite. Arsenic is used mainly to preserve wood and to control insects and weeds.
How is arsenic released by electric utilities?
Trace amounts of arsenic are present in coal and oil. When electric utilities burn these fuels at their power plants, arsenic is released in very small amounts. Calcium arsenate is likely to be the arsenic compound most frequently released. Most of this arsenic is carried by particles of ash. It is mainly on the surface of the particles. Coal-burning power plants are equipped with devices to capture ash particles before they reach the air. Particle control services typically capture more than 99% of the ash, so very little ash enters the air. Arsenic-carrying ash captured by these devices is usually sent to ash ponds or land disposal sites. Power plants reporting to the U.S. Environmental Protection Agency (EPA) released 3,440 tons of arsenic into the environment in 1998. This was about 1% of all the arsenic released by industries reporting to EPA that year.
Is arsenic also released byother sources?
Natural arsenic occurs commonly and comes mainly from the soil. Estimates are that the amount of natural arsenic released into the air as dust from the soil is about equal to the amount of arsenic released by all human activities. An estimated 75% of all arsenic released by human activities comes from metal production, such as copper smelting. Industries reporting to EPA released 304,320 tons of arsenic into the environment in 1998. Most was released to the land.
What happens to arsenic after it is released by electric utilities?
Ash particles carrying arsenic settle to the ground after they are released into the air from power plants. Arsenic compounds that dissolve in water are carried to the ground by rain and snow. Other arsenic compounds that don’t dissolve reach the ground through gravity and air turbulence. Ash pond wastewater discharged into public waterways may contain small amounts of dissolved arsenic, but local permits regulate these amounts.
How might people be exposed to arsenic?
Arsenic is common in the environment and people are exposed to small amounts of arsenic in their diet—for example, by eating shellfish. They may breathe smoke or particles from wood containing arsenic preservatives, and workers may breathe airborne arsenic on the job if they fail to wear protective masks.
What are the potential effects of arsenic on human health?
Very small amounts of arsenic in people’s diets may be necessary for good health. But the kind of arsenic in the diet is important. Organic arsenic compounds (those containing carbon) are much less toxic than inorganic arsenic compounds (those containing no carbon). For example, eating organic arsenic compounds that accumulate in fish and shellfish is unlikely to harm human health. Eating or drinking large amounts of inorganic arsenic can be toxic, even fatal. Exposure to large amounts of inorganic arsenic can cause stillbirths and birth defects, and can damage blood vessels, skin, nerves, and the heart. According to EPA and the U.S. Department of Health and Human Services, inorganic arsenic—even in very small amounts—is a cancer-causing agent. For example, eating or drinking inorganic arsenic may increase the risk of skin cancer and tumors of the bladder, kidney, liver, and lung. Breathing inorganic arsenic may increase the risk of lung cancer, according to studies of workers exposed to dust from copper-smelter operations.
Copper-smelter dust may irritate the lungs. This irritation may be one of the critical reasons why copper-smelter workers appear to have an increased risk of lung cancer. Lung irritation appears less likely from breathing power plant ash because it contains a less-toxic form of inorganic arsenic.
How likely is it that utility releases pose a risk to human health?
It is unlikely that arsenic from power plants poses a significant risk to human health. EPA has evaluated the potential health risks of breathing arsenic for people who live near power plants that burn coal and oil. EPA estimates that a person living all his life near one of these plants would have one chance in a million (or less) of developing cancer as a result of his exposure to power plant arsenic. According to EPA, only four plants out of nearly 600 in the United States posed cancer risks from arsenic exposure just slightly greater than these. Researchers are investigating several important issues about the possible health effects of arsenic in power plant ash. One issue is which form of inorganic arsenic to use in estimating health effects. Inorganic arsenic produced by copper smelting is about ten times more toxic than inorganic arsenic in power plant ash. By basing its current estimate of arsenic health effects on the more toxic form of inorganic arsenic in copper-smelter dust, EPA has set a standard that may be much more conservative than needed to protect human health in the community. Also, EPA may have substantially overestimated the ability of arsenic to cause cancer when people breathe it. Although research is underway on these issues, we don’t have all the answers yet.
How is arsenic regulated?
EPA regulates public exposure to arsenic in drinking water and has published an estimate of the cancer risks related to drinking different amounts of arsenic. EPA also has published water quality standards to protect freshwater life, such as fish, from exposure to inorganic arsenic. Under the National Pollutant Discharge Elimination System, federal and state regulators determine how much arsenic each power plant may release in wastewater discharges. The Occupational Safety and Health Administration has set limits on the amount of arsenic in workplace air.
Where can I get more information about arsenic?
The Agency for Toxic Substances and Disease Registry (ATSDR) has a fact sheet with answers to frequently asked health questions about arsenic. It is available through the ATSDR Information Center at 1-800-447-1544 or on the Internet-http://www.atsdr.cdc.gov/tfacts2.html. EPA also has a fact sheet that is available on the Internet at http://www.epa.gov/ttnatw01/hlthef/arsenic.html

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© 2000 Electric Power Research Institute (EPRI), Inc.
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BARIUM

What is barium?
Barium is a silver-white metal that makes up 0.05% of the earth’s crust. Small amounts of naturally occurring barium are present in food and drinking water.
How is barium used?
Barium is naturally present in coal that is mined and used to generate electricity. Trace amounts of barium compounds are present in the coal ash that results from this use. The coal ash is used to enhance reclamation at coal mines under the oversight of state and federal agencies. Barium compounds are also used in the manufacture of ceramics and as part of certain medical test procedures.
Does the mining industry release barium into the environment?
Very small amounts of barium remain in the coal ash generated from electricity production. The coal ash is used in managed and controlled environments to enhance reclamation efforts at coal mines.
How could I be exposed to barium?
Exposure to barium can occur in the following ways: food consumption, inhalation and direct skin contact (which is very rare). The amount of barium in food and water supplies poses little or no health concern. In fact, the human body requires a certain level of barium to maintain good health.
What does the EPA say?
Federal agencies regulate barium releases in order to protect the public health and the environment. The EPA has established a maximum level of 1.1 ppm of barium in drinking water. The EPA also has said that an average-sized adult exposed to 1.5 ppm of barium every day for 70 years will not experience adverse health effects.

CHROMIUM

What is chromium?
Chromium is a gray, solid material that is found naturally in rocks, animals, plants, soil, and volcanic dust and gas. It is an essential nutrient for humans that promotes the metabolism of sugar, protein, and fat, so small amounts of chromium in the diet are necessary for good health.
How is chromium used?
Chromium exists naturally on the earth's surface, but releases to the atmosphere are usually attributed to human activities. Airborne chromium usually settles back to earth within 10 days, so chromium levels in the atmosphere are very low. Airborne chromium releases result from metal fabrication, cement production, use of asbestos-lined brakes, waste incineration, automotive catalytic converters, cooling towers that use chromate chemicals as rust inhibitors (currently being phased out) and fossil fuel (natural gas, oil, and coal) combustion.
Does the mining industry release chromium into the environment?
Very small amounts of chromium are naturally present in rocks and soils and are released into the environment by moving these materials as well as by the natural erosion and weathering processes. Coal-burning electric utilities in the U.S. are responsible for about 2% of human-induced chromium releases into the atmosphere each year.
How could I be exposed to chromium?
Exposure to chromium can occur in the following ways: food consumption (accounts for more than 96% of daily chromium exposure for most people), inhalation, drinking water, and skin contact (from using consumer products like wood preservatives, cleaning products, cement, and textiles.) People who work in industries that use chromium such as chromate and chrome pigment production, stainless steel production, welding, chrome plating, leather tanning, painting, copy machine service, and manufacturing of batteries, dyes, and cement can be exposed to higher levels of the metals.
What does the EPA say?
The EPA has concluded that chromium from coal-burning power plants readily converts to a form that does not pose a risk to human health. The Agency does not consider the cancer risk from ingestion of chromium to be a serious health threat. Nonetheless, to protect safe drinking water, EPA has set a maximum level of 100 parts of chromium per billion parts of water (ppb). Standards from the Occupational Health and Safety Administration (OSHA) regulate the amount of chromium present in workplace air.

COBALT

What is cobalt?
Cobalt (Co) is a shiny gray metal that is hard and magnetic. In nature, it usually combines with other elements to form cobalt compounds. Small amounts of these compounds are naturally present in soils, rocks, and water. Cobalt combines with other metals to form mixtures called alloys. Some of these are “superalloys” that maintain their strength at very high temperatures. For example, a superalloy of cobalt and steel is used in manufacturing jet engines. Cobalt is also used in paint and porcelain enamel finishes as a drying agent, in wear-resistant cutting and grinding tools, in electronic components that rely on its magnetic properties, and in formulating vitamin B12 . Physicians implant artificial hip and knee joints made of cobalt alloys and use man-made isotopes of cobalt for radiation therapy.
How is cobalt released by electric utilities?
Trace amounts of cobalt are present in coal and oil. When electric utilities burn these fuels at their power plants, cobalt is released. Most of this cobalt is carried by particles of ash. Coal-burning power plants are equipped with devices to capture ash particles before they reach the air. Particle control devices typically capture more than 99% of the ash, so very little ash enters the air. Cobalt-carrying ash captured by these devices is usually sent to ash ponds or land disposal sites. Power plants reporting to the U.S. Environmental Protection Agency (EPA) released 2,096 tons of cobalt into the environment in 1998. This was about 29% of all the cobalt released by industries reporting to EPA that year.
Is cobalt also released by other sources?
Cobalt is released into the air by soils as they erode in wind and rain, by volcanoes when they erupt, and by forest fires and seawater evaporation. Cobalt released by human activities comes mainly from nickel, copper, silver, lead, and iron mines and refineries; metal production facilities; industrial boilers that burn coal and oil; vehicles that burn gasoline; and incinerators that burn refuse and sewage sludge. Industries reporting to EPA released 7,336 tons of cobalt into the environment in 1998. Most was released to the land.
What happens to cobalt after it is released by electric utilities?
Ash particles carrying cobalt settle to the ground after they are released into the air from power plants. Cobalt compounds that dissolve in water are carried to the ground by rain and snow. Other cobalt compounds that don’t dissolve reach the ground through gravity and air turbulence. Cobalt may stay in water and soil for years. Ash pond wastewater discharged into public waterways may contain small amounts of cobalt, but these amounts are regulated by local permits.
How might people be exposed to cobalt?
People are commonly exposed to small amounts of cobalt naturally present in the air they breathe, the water they drink, and the foods they eat. For example, leafy green vegetables are a natural source of cobalt in people’s diets. Industrial workers may breathe cobalt dust or fumes, or touch substances that contain cobalt.
What are the potential effects of cobalt on human health?
Very small amounts of cobalt in people’s diets are necessary for good health. These amounts can be supplied by vitamin B12, a compound that contains cobalt. Cobalt also benefits health when it is used to stimulate red blood cell production in the treatment of anemia. However, some people exposed to small amounts of cobalt for a long time develop an allergic reaction to it. The most common reaction is itching when cobalt contacts their skin. In less common, severe cases, people experience vomiting when they swallow cobalt or asthma attacks when they breathe it. People who are not allergic have health problems only when they are exposed to very large amounts of cobalt not normally found in the environment. For example, some breweries used to add cobalt to beer to stabilize the foam. Drinking large quantities of this beer caused serious heart problems, and the practice of adding cobalt has been discontinued. Breathing large amounts of cobalt for a long time may cause asthma, pneumonia, liver and kidney damage, and thyroid problems. Although research is ongoing, cobalt has not been found to cause cancer in people.
How likely is it that utility releases pose a risk to human health?
It is unlikely that cobalt from power plants poses a significant risk to human health. EPA has evaluated the potential health risks of breathing cobalt for people who live near power plants that burn coal or oil. In EPA’s initial screening assessment, these risks were so low that the Agency eliminated utility cobalt from further analysis as an inhalation health hazard. Since airborne ash particles carrying cobalt are widely scattered before they settle to the ground, it is unlikely that ash from power plants significantly increases the amount of cobalt in soil, water, or food.
How is cobalt regulated?
EPA requires that 1000 pounds or more of cobalt be reported if it is spilled or released without a permit. Under the National Pollutant Discharge Elimination System, federal and state regulators determine how much cobalt each power plant may release in waste-water discharges. The Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have set limits on the amount of cobalt in workplace air. The Nuclear Regulatory Commission regulates radioactive isotopes of cobalt.
Where can I get more information about cobalt?
The Agency for Toxic Substances and Disease Registry (ATSDR) has a fact sheet with answers to frequently asked health questions about cobalt. It is available through the ATSDR Information Center at 1-800-447-1544, or on the Internet at http://www.atsdr.cdc.gov/tfacts33.html. EPA also has a fact sheet that is available on the Internet at http://www.epa.gov/ttnatw01/hlthef/cobalt.html

COPPER

What is copper?
Copper, a salmon-pink metal containing both silver and gold, is non-magnetic, tough, moderately hard, resistant to wear, and has a bright metallic luster when polished. The strength, ductility, corrosion resistance and ability to conduct heat and electricity make copper an element of great importance.
How is copper used?
Historically, copper was used for making tools and weapons and as an ornamental metal. Today copper is used in electroplating, wiring, plumbing, medicine and agriculture. Copper is the standard benchmark for electrical conductivity. It conducts electrical current better than any other metal except silver.
Does the mining industry release copper into the environment?
Copper is a very abundant, naturally occurring element present in the earth’s crust. Most of the world’s copper is mined in the U.S. and copper is “released” into the environment during the mining process as these materials are removed from the earth, transported and processed. Copper is also released naturally by weathering and natural erosion processes.
How could I be exposed to copper?
Copper is a natural element found in the earth's crust. As a result, most of the world's surface water and ground water used for drinking, contains copper. Naturally occurring copper in drinking water is safe to drink, even in instances where the copper level is high enough to add a metallic taste to the water. Copper is an essential nutrient required by the body in daily dietary amounts of 1 to 2 milligrams for adults (½ to 1 milligram for children). Too little copper in the body can actually lead to disease. Copper is involved in maintaining the balance of other useful metals in the body such as zinc and molybdenum. Sources of copper in our diet include drinking water, potatoes, legumes, nuts, grains, fruits and chocolate. Copper is used in many consumer products. In a small number of these products, copper is released during the course of their normal use. An example is copper in roadway dust, shed from automobile brakes during their normal use.
What are the health risks associated with copper?
Like all substances, excessive copper can make people ill when ingested and may cause stomach upset, nausea, and diarrhea but this only occurs in cases where the copper levels significantly exceed the World Health Organization limits for copper in drinking water. In fact, the World Health Organization has concluded that copper deficiency is much more of a global problem than copper toxicity. Acute copper poisoning is a rare event, largely restricted to the accidental drinking of solutions of copper nitrate or copper sulfate, which should be kept out of easy access in the home. These and organic copper salts are powerful emetics and inadvertent large doses are normally rejected by vomiting. Chronic copper poisoning is also very rare and the few reports refer to patients with liver disease. The capacity for healthy human livers to excrete copper is considerable and it is primarily for this reason that no cases of chronic copper poisoning have been reported.

CYANIDE

What is cyanide?
What is cyanide? Cyanide is a compound of carbon and nitrogen, two of the most common elements in the earth’s crust. It is produced naturally in a number of microorganisms, insects and plants. Cyanide occurs in at least 800 species of plants including apples, broccoli, brussel sprouts, cabbage, cauliflower, cherries, lima beans, radishes, almonds, and turnips. It existed on earth before life began and was one of the fundamental building blocks in the evolution of life. Today it is a chemical manufactured for use in a number of important industries. Cyanide is used in the processing of pharmaceuticals, plastics, dyes, pigments, and in plating of various metals. It is also used to prevent caking and lumping of table salt and road salt.

The EPA reported in December 1985 cyanide risk assessment, An Exposure and Risk Assessment for Cyanide (EPA-440/4-85-008):
- The overall acute risks to humans as a result of cyanide in the environment appear to be negligible. This is because of the ability of humans to detoxify cyanide rapidly at low exposure levels typically found in the environment.
- Approximately 90% of the cyanide released into the atmosphere was from automobiles. (Since 1981 automobile emissions have been greatly reduced. Today the main releases of cyanide into the world’s atmosphere come from incomplete combustion in wild fires, wood burning and from volcano eruptions.)
- Approximately two-thirds of the cyanide entering surface waters was via sewage treatment plants originating from road salt, metal finishing and organic chemical industries. (Since 1981 releases from metal finishing and the chemical industries have been substantially reduced.)
How is cyanide used?
- About 80% of the cyanide produced is used in the production of synthetics (e.g., nylon, pesticides, etc) and in other manufacturing processes (e.g., electroplating, pharmaceuticals, etc.).
- About 20% of the cyanide is used in mining in the form of sodium cyanide.
Why is cyanide the chemical of choice for gold recovery?
Cyanide is one of the very few chemical reagents that will dissolve gold in water, using only oxygen from the air as an oxidizing agent. Other chemicals will work but only in much higher concentrations using much stronger oxidizing agents e.g. chlorine, nitric acid or hypochloride. At these higher concentrations they can be more dangerous to handle than cyanide. Therefore, cyanide is the chemical of choice for the recovery of gold from ores. It has been used in metal extraction since 1887 and is safely used and managed in gold recovery around the world.
How is cyanide used in other mining applications?
Cyanide can also be used in ore-processing to suppress undesirable metals. Used in this way, a trace amount of cyanide is added to a large volume of crushed ore and water during ore-processing. In this type of application, the amount of cyanide solution added is small and reacts quickly so that it may not be detectable in the process after it has been added.
How could cyanide affect me?
Cyanide is used at mines in very low concentrations in water, typically 0.01% to 0.05% cyanide. Its use is tightly controlled and monitored at the mine site. Employees are trained to handle cyanide very carefully and the manufacture, transport, storage, use and disposal of cyanide are strictly regulated and have been accomplished safely for decades.
- At gold mines, all tanks, pipes, ponds and other areas that contain cyanide are required by law to have appropriately designed and engineered containment facilities. This means that if there is any problem, there is a back-up system to contain the material.
- Cyanide in mining solutions is collected either to be recycled or effectively destroyed to permitted levels on-site after gold is removed.
- Cyanide is destroyed quickly when required using several commonly available chemicals kept at all mines.
- Cyanide is naturally degraded, generally by oxidation, and is not persistent in the environment.
- Cyanide does not bioaccumulate and is not carcinogenic, mutagenic or tetratogenic.
- While cyanide is common in nature in small dosages, it can be hazardous to health in higher dosages if improperly handled or managed.
Where can I get more information on cyanide?
- The Colorado Mining Association, 216 16th Street, Suite 1250, Denver, CO 80202
- The National Mining Association, 101 Constitution Avenue, NW Suite 500 East, Washington, DC 20001
- The Gold Institute, 1112 16th Street, Suite 240, Washington, DC 20036
- Office of Water, U.S. Environmental Protection Agency
- The International Council of Metals and The Environment 294 Albert Street, Suite 506, Ottawa, Ontario, Canada K1P 6E6
- The Cyanide Monograph, Dr. T.I. Mudder (Editor), 1998; The Chemistry and Treatment of Cyanidation Wastes, A.C.S. Smith and Dr. T.I. Mudder, 1991, Mining Journal Books, London, United Kingdom
- Cyanide Management Guideline, 1992, Western Australian Department of Minerals and Energy
- Clinical and Experimental Toxicology of Cyanides, B. Ballantyne and T. Marrs, 1987, Wright Publishers, Bristol, United Kingdom
- "Cyanide Hazards to Fish, Wildlife and Invertebrates: A Synoptic Review", R. Eisler, 1991, U.S. Fish and Wildlife Service, Biological Reports v. 85
- Cyanide Management, Environment Australia, 1998, a booklet in a series on Best Practice Environmental Management in Mining, Commonwealth of Australia
- Technical Guide for Environmental Management of Cyanide in Mining, T.W. Higgs & Associates, 1992
- Mining Environmental Management Magazine, June, 1995, Special Issue on Cyanide

DIOXIN

What are dioxins?
Dioxins are colorless, odorless solids. They are part of a family of 210 organic compounds that contain carbon, oxygen, and hydrogen arranged in a unique chemical structure. Replacing hydrogen with chlorine in certain positions in that structure creates 17 compounds that the U.S. Environmental Protection Agency (EPA) considers harmful to human health. They include polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs). EPA calls this group dioxins or dioxin-like compounds. Dioxins are unwanted by-products of natural events and human activities. Very tiny amounts of dioxins are present in soils, plants, underwater sediments, water, and air. They have no useful commercial function.
How are dioxins released by electric utilities?
Although no one knows exactly how dioxins form when power plants burn fuel, the following process seems most likely. Trace amounts of chlorine are present in coal and oil. When electric utilities burn these fuels in their power plants, chlorine is released. Some of this chlorine takes the place of hydrogen in specific organic compounds to create very small amounts of dioxin vapor. These amounts are so small that only highly specialized sampling and analysis can measure them. As dioxin vapor cools, it forms thin films on tiny ash particles. Coal-burning power plants are equipped with devices to capture ash particles before they reach the air. Particle control devices typically capture more than 99% of the ash, so very little ash enters the air. Ash captured by these devices is usually sent to ash ponds and land disposal sites. Dioxins from power plants were about 2-3% of all dioxins from human activities released into the air in the United States in 1995.
Are dioxins also released by other sources?
Dioxins are released into the air by soils as they erode in wind and rain, by volcanoes when they erupt, and by forest fires. These natural releases are smaller than those from human activities. Dioxins released by human activities come mainly from incinerators that burn refuse, sewage sludge, and medical waste; backyard trash burners; landfills experiencing accidental fires; copper smelters; cement kilns; pulp and paper mills that use chlorine bleach; vehicle exhaust pipes; and wood-burning stoves and fireplaces. Dioxin releases from human activities in the United States peaked in the 1970s and have since declined about 80%. According to EPA, changes responsible for this decline include eliminating most open burning of solid wastes, installing particle control devices on combustion burners, phasing out leaded gasoline, and banning or restricting the use of chemicals that contain dioxins.
What happens to dioxins after they are released by electric utilities?
Some ash particles carrying dioxins settle to the ground through gravity and air turbulence relatively near their source. Other particles travel further into the atmosphere, where they may remain for months. Eventually, these particles return to earth where they fall on soil and growing plants, and into bodies of water. Dioxins may remain in soil and underwater sediments for years. They build up in fish and in the fatty flesh of animals that eat plants, but not in the plants themselves. Ash pond wastewater discharged into public waterways may contain very tiny amounts of dioxins. Dioxins are noted on local discharge permits.
How might people be exposed to dioxins?
People are commonly exposed to very tiny amounts of dioxins present in the air they breathe, the water they drink, and the foods they eat. For example, nursing infants are exposed to very tiny amounts of dioxins in their mothers’ milk. However, people who eat large amounts of meat and dairy products that are high in fat, or large amounts of fish that have accumulated dioxins in their body fat, may have greater exposure. EPA estimates that 95% of exposure to dioxins comes from eating animal fats. Because fewer dioxins are being released into the environment and people are eating less animal fat, the amount of dioxin measured in their bodies is decreasing. Those who smoke may inhale dioxins found in tobacco, and industrial workers may breathe dioxins or touch substances that contain them. For example, an accidental explosion at a chemical plant in Seveso, Italy in 1976 contaminated the surrounding environment and exposed workers and local citizens to large amounts of dioxins. Military personnel in Vietnam were exposed to dioxins while using the herbicide, Agent Orange. Products known to contain dioxins, such as the pesticide 2,4,5-T and PCB dielectric fluids, are no longer sold.
What are the potential effects of dioxins on human health?
Dioxins are considered to be very toxic substances. People exposed to large amounts of dioxins experience a skin disease called chloracne. Some studies have shown that high exposures also may contribute to the development of liver, kidney, heart, thyroid, and blood disorders, as well as adult onset diabetes and cancer. Eating the very tiny amounts of dioxins commonly present in food apparently does not make people sick. However, because dioxins build up in the human body, researchers are studying ways in which they might affect health over time—perhaps by altering normal reproduction, development, and immunity to disease. Laboratory animals develop liver cancer when they eat food containing 2,3,7,8-TCDD, the most toxic form of dioxin. Based on animal and human studies, EPA has classified 2,3,7,8-TCDD as a “human carcinogen” and other dioxins as “likely human carcinogens.”
How likely is it that utility releases pose a risk to human health?
It is unlikely that dioxins from power plants pose a significant risk to human health. EPA has evaluated the potential cancer risk of exposure to dioxins from power plants. To do this, EPA modeled 16 different theoretical risk scenarios. In the highest risk scenario, adults lived near a large coal-fired power plant and relied on locally caught fish for much of their food. If 10,000 of these adults stayed in the same location and ate fish every day of their lives, 2 occurrences of cancer among them would be due to power plant dioxins. In the lowest risk scenario, children lived near a large oil-fired power plant and ate a typical American diet. If 1 billion of these children stayed in the same location all their lives, 1 occurrence of cancer among them would be due to power plant dioxins. EPA has not yet developed a method for evaluating non-cancer health risks from exposure to dioxins. Since airborne ash particles carrying dioxins are widely scattered before they settle to the ground, it is unlikely that ash from power plants significantly increases the amount of dioxins in soil, water, or food.
How are dioxins regulated?
EPA has established limits for dioxins in drinking water. The Agency requires that 1 pound or more of 2,3,7,8-TCDD be reported if it is spilled or released without a permit. EPA regulates dioxins released into the air by waste incineration (including hazardous waste burning), dioxins released into wastewater from pulp and paper manufacturing, and dioxins applied to the land in wastes used as fertilizers or soil amendments. EPA also regulates the manufacture and use of products contaminated with dioxins. The Food and Drug Administration has set a “safe level” for dioxins in fish that will be eaten. The Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health recommend reducing workplace exposure to dioxins to the lowest feasible level.
Where can I get more information about dioxins?
Those interested in detailed information about dioxins from power plants may read EPA’s 1998 Final Report to Congress, Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units. This report is available on the Internet at http://www.epa.gov/ttn/oarpg/t3rc.html

EPRI, 3412 Hillview Avenue, P.O. Box 10412, Palo Alto, California 94303 U.S.A.
800.313.EPRI or 650.855.2000 www.epri.com
© 2001 Electric Power Research Institute (EPRI), Inc.
All rights reserved. Electric Power Research Institute, and EPRI are registered service marks of the Electric Power Research Institute, Inc.

LEAD

What is lead?
What is lead? Lead is a naturally occurring, bluish-gray metal that has no taste or smell. It is found in small amounts in soil and water.
How is lead used?
Lead has a variety of uses, including roofing, x-ray shields, batteries, metal products (sheet lead, solder, some brass and bronze products, pipes, etc.), iron and steel production and ceramic glaze.
Where can lead be found?
Automotive emissions that have settled result in lead in the soil. Lead is also found in paint in older houses. Remodeling older homes often disturbs lead-based paints and produces lead dust. Since the late 1970s, the U.S. has slowly reduced air emissions of lead. The largest decreases were made in industrial process releases and, since leaded gas was outlawed, auto emissions. A very small amount of lead was released to surface water in 1996 (less than .4% of documented releases). In addition to industrial sources, urban industrial runoff and settling of airborne lead particles are significant sources for lead in bodies of water.
Does the mining industry release lead into the environment?
Small amounts of lead occur naturally in soils, rocks and groundwater and are released to land by moving these materials as well as by the natural erosion and weathering processes. Lead concentrations in the soil are between one part of lead per million parts of soil (ppm) and 300 ppm.
How could I be exposed to lead?
Most humans’ intake of lead can be attributed to consumption of food and drinking water that contains lead (smoking, wine consumption) as well as inhalation of airborne particles or skin contact (proximity to lead paint). Very small quantities of lead are found in lakes, rivers, and groundwater that supply drinking water. In fact, more than 99% of all publicly supplied water contains less than three parts lead for every billion parts of water (ppb), which is considered extremely good.
What does the EPA say?
The EPA regulates the amount of lead released to the air and water, and the Consumer Product Safety Commission sets lead standards for consumer products and school facilities.

MANGANESE

What is manganese?
Manganese is a silver-colored metal. In nature, it is combined with other elements to form manganese compounds. These compounds are naturally present in soil, rocks, and water. The levels in the soil vary from 10 to 5,000 parts of manganese for every million parts of soil (ppm).
Where is manganese released?
Manganese is released into the environment by the natural erosion of rocks and soils. Most manganese is released by these natural sources. Manganese released by human sources comes mainly from steel mills. Total emissions of manganese have dropped dramatically over the past 20 years.
- Air releases: In 1978, U.S. industry emitted 18,000 tons of manganese into the air. In 1995, air releases of manganese and manganese compounds were 1,750 tons.
- Water releases: Analysis of background levels in surface water and groundwater indicate that human activities are responsible for only a fraction of total water-borne manganese. Most of it is naturally occurring.
- Land releases: In 1996, EPA's TRI reported that 30,595 tons of manganese and manganese compounds were released to the soil by industrial sources in the U.S.
Does the mining industry release manganese into the environment?
Very small amounts of manganese are naturally present in rocks and soils and can be released into the environment as dust by moving these materials as well as by natural erosion and weathering processes. Manganese is also present in coal, which is used to generate electricity. When coal is burned, ash is produced which retains most of the naturally occurring manganese. More than 99% of the ash is collected and is either sent to disposal sites or recycled into commercial products.
How could I be exposed to manganese?
Manganese exists naturally in the human body. The total amount of manganese tends to remain stable even when consumption rates are high. Generally, about 3-5% of the manganese intake will remain in the body. Food is the largest source of manganese intake by humans. Trace amounts of manganese are found in most foods. Manganese levels in drinking water are very low -- about four parts of manganese to every billion parts of water (ppb). Exposure to manganese through food and water is of little concern since the body regulates most of it.
What does the EPA say?
EPA has determined that the level of manganese exposure due to burning coal for electricity is well below the level at which health effects are seen.

MERCURY

What is mercury?
Mercury (Hg) is a silver-colored metal that is liquid at room temperature. It commonly occurs in water and soil. Mercury is the familiar silver column in thermometers. It is also used in fluorescent lights, some kinds of batteries, and dental fillings.
How is mercury released by electric utilities?
Trace amounts of mercury are present in coal and oil. When electric utilities burn these fuels at their power plants, mercury is released. Most of this is mercury gas. Power plants pass stack gases through pollution control devices that may remove mercury before it enters the air. Wastes captured by these devices are usually sent to ash ponds or land disposal sites. Power plants reporting to the U.S. Environmental Protection Agency (EPA) released no mercury above the reporting threshold in 1998. After declaring mercury to be a “persistent bioaccumulative toxic” substance, EPA lowered its reporting threshold for 1999. According to this more sensitive measure, coal-burning power plants reporting to EPA released 45 tons of mercury into the air in 1999. Compared with the 52 tons EPA estimated in 1994, this shows that power plants are releasing less mercury into the air today. Mercury from U.S. power plants is about one-third of all the mercury released into the air by human activities in the United States, and is less than 1% of all the mercury released into the air each year around the globe.
Is mercury also released by other sources?
Natural sources around the globe—such as ocean surfaces, mercury-rich soils, and volcanoes—release about 58% of all the mercury entering the air each year. In the past, people released large amounts of mercury by manufacturing pesticides and chlorine-based industrial products, and by mining. Today, people release mercury mainly by burning coal, and wastes from cities and hospitals. Mercury releases from human activities in the United States peaked about 1960 and are now declining. Industries reporting to EPA released 4,681 tons of mercury into the environment in 1998. Most was released to the land.
What happens to mercury after it is released by electric utilities?
Mercury released by power plants becomes part of a global cycle. The behavior of mercury in this global cycle depends on its chemical form. Oxidized mercury easily washes out of the air and returns to earth relatively near its source. In contrast, elemental mercury usually travels further into the atmosphere, where it may remain for months. Eventually, this “background” mercury returns to earth and enters bodies of water and soils. Estimates are that about one-third of the mercury reaching the earth binds to the soil. As part of a broad investigation of how mercury behaves, researchers are studying how much mercury from power plants enters the atmosphere and how much returns to earth close to the plants that release it. They estimate that about half the mercury from power plants is elemental mercury that enters the atmosphere and eventually settles to earth at points around the globe. Once mercury reaches the earth, it can enter natural ecosystems. For example, oxidized mercury can enter lakes and streams where bacteria may chemically change it to methylmercury, the organic form of mercury most easily taken up by fish and animals.
How is mercury released by electric utilities?
Trace amounts of mercury are present in coal and oil. When electric utilities burn these fuels at their power plants, mercury is released. Most of this is mercury gas. Power plants pass stack gases through pollution control devices that may remove mercury before it enters the air. Wastes captured by these devices are usually sent to ash ponds or land disposal sites. Power plants reporting to the U.S. Environmental Protection Agency (EPA) released no mercury above the reporting threshold in 1998. After declaring mercury to be a “persistent bioaccumulative toxic” substance, EPA lowered its reporting threshold for 1999. According to this more sensitive measure, coal-burning power plants reporting to EPA released 45 tons of mercury into the air in 1999. Compared with the 52 tons EPA estimated in 1994, this shows that power plants are releasing less mercury into the air today. Mercury from U.S. power plants is about one-third of all the mercury released into the air by human activities in the United States, and is less than 1% of all the mercury released into the air each year around the globe.
How might people be exposed to mercury?
People are most often exposed to methylmercury when they eat fish or shellfish. Because fish may accumulate methylmercury in their bodies, older predatory fish usually have the most methylmercury. People may also breathe elemental mercury from industrial sources or broken thermometers.
What are the potential effects of mercury on human health?
Because the body can naturally eliminate mercury, occasional exposure to relatively small amounts of mercury is believed to have no effect on human health. Exposure to large amounts of mercury—either from eating methylmercury or breathing elemental mercury—can cause kidney, brain, and nerve damage or even death. It can also affect the unborn babies of pregnant women. Our knowledge of how large amounts of methylmercury can affect people’s health comes from two accidental poisoning incidents—one in Japan in the 1950s and another in Iraq in the 1970s—where people ate massive amounts of methylmercury. In Iraq, researchers observed that it took less methylmercury to affect babies developing in the womb than to affect adults. For this reason, it is a public health goal to limit methylmercury exposure especially for women of childbearing age. Methylmercury apparently does not cause cancer, based on long-term observations of the people exposed in Japan and Iraq.
How likely is it that utility releases pose a risk to human health?
Health risks from power plants depend largely on how much those plants influence the amount of methylmercury in fish that people eat. It is unlikely that U.S. power plants have a measurable effect on the amount of methylmercury in ocean fish living far from our shores. Nor do they impact fish raised on commercial diets at fish farms. These kinds of fish account for about 90% of the U.S. seafood diet. However, mercury releases from U.S. power plants may influence the amount of methylmercury in freshwater fish living in some U.S. lakes and streams. In several case studies sponsored by EPRI, independent researchers found that the amount of methylmercury in lake fish that might come from nearby power plants was well below the amount that EPA says people may take into their bodies without harming their health. For an average person who weighs about 150 pounds, the amount that EPA currently considers safe is up to 7 micrograms of methylmercury each day—about one fish meal a week, if the fish contain average amounts of methylmercury. In 1997, an office of the U.S. Public Health Service proposed that people could safely take in 5 times as much methylmercury, up to 35 micrograms each day—almost one fish meal every day. This government agency based its proposal on new studies of the way methylmercury affects children born to mothers who ate seafood containing it when they were pregnant. Although these levels are set by the government to protect the health of its most sensitive residents, average consumers in the United States need not be concerned with exposure to methylmercury.
How is mercury regulated?
At freshwater lakes and rivers known to be contaminated with mercury, many states post “fish advisories” telling fishermen how many and which kinds of fish their families can safely eat. These advisories are aimed especially at protecting pregnant women and small children from harmful exposure to methylmercury, and are based on limits established by FDA or by the states. EPA regulates public exposure to mercury in drinking water and has published water quality standards to protect freshwater life, including fish, from exposure to mercury. EPA also requires that 1 pound or more of mercury be reported if it is spilled or released without a permit. The Occupational Safety and Health Administration has a limit for mercury in workplace air.
Where can I get more information about mercury?
The Agency for Toxic Substances and Disease Registry (ATSDR) has a fact sheet with answers to frequently asked health questions about mercury. It is available through the ATSDR Information Center at 1-800-447-1544, or on the Internet http://www.atsdr.cdc.gov/tfacts46.html. EPA also has a fact sheet that is available on the Internet at http://www.epa.gov/ttnatw01/hlthef/mercury.html. Those interested in detailed information about mercury may read the Mercury Study Report to Congress, EPA-452/ R-97-003, December 1997. This report, published by the EPA Office of Air Quality Planning and Standards and Office of Research and Development, is available on the Internet at http://www.epa.gov/ttnatw01/112nmerc/mercury.html

EPRI, 3412 Hillview Avenue, P.O. Box 10412, Palo Alto, California 94303 U.S.A.
800.313.EPRI or 650.855.2000 www.epri.com
© 2000 Electric Power Research Institute (EPRI), Inc.
All rights reserved. Electric Power Research Institute, and EPRI are registered service marks of the Electric Power Research Institute, Inc.

NICKEL

What is nickel?
Pure nickel is a hard, silvery-white metal. It is released into the environment by volcanoes, forest fires, vegetation, and human activities.
Where does nickel come from?
Nickel is found in all soil. Soil-based concentrations range from 400 to 80,000 parts of nickel for every billion parts of soil (ppb). Nickel enters streams and bodies of water through natural weathering and erosion processes as well as by settling of atmospheric nickel emissions. Water-borne nickel often accumulates in sediments. Nonetheless, nickel levels in surface water are normally very low (often undetectable). Most manmade nickel releases (75%) are to land. The largest sources of nickel in the soil are waste from metal manufacturing, commercial waste, urban refuse, coal ash and sewage sludge. The remainder of human-induced nickel releases are atmospheric. Approximately 295 tons of nickel and nickel compounds were released from manmade sources to the air. Atmospheric emissions remain airborne for about 30 days, and eventually settle back to earth.
How is nickel used?
High natural, land-based nickel concentrations are frequently mined. There is only one nickel mine operating in the U.S., but active mines are found in Canada, Cuba, Indonesia, the Dominican Republic, the Philippines, and Brazil. Most of the nickel used in the U.S. is produced from recycled nickel alloys and is used to produce metals such as steel. Nickel is often alloyed with iron, copper, chromium, or zinc to make products like stainless steel, metal coins, and industrial items. Nickel can also combine with chlorine, sulfur, or oxygen to form compounds used in nickel plating, color ceramics, and batteries.
Does the mining industry release nickel into the environment?
Very small amounts of nickel are naturally present in rocks and soils and are released into the environment by moving these materials as well as by the natural erosion process. Nickel is also naturally present in fossil fuels like coal, which is burned to generate electricity. The burning of coal produces ash, which contains much of the naturally occurring nickel. Power plants are equipped with devices that capture more than 99% of the ash, which is then sent to disposal sites, or is recycled into commercial products.
What does the EPA say?
Based on the EPA’s estimates, the health risk associated with electric utility nickel emissions is very low. However, research is underway to assess any potential health effects related to nickel.

NITRATE (aqueous solution)

What is nitrate?
Nitrate is a compound of nitrogen and oxygen, two of the most common elements in the earth’s atmosphere and crust. It is produced as the end product of the oxidation of organic nitrogen, and to a lesser extent through the introduction of nitrogen fertilizer and the degradation of industrial chemicals. It is a common constituent in domestic sewage treatment systems, as well as of other biological decay processes. It is a component of fertilizer and it is used as a compound (e.g., nitric acid) in many industries.
How is nitrate formed in mining applications?
Nitrate is a component of the fertilizer that may be mixed with diesel fuel and employed with a detonating device for blasting both ore and overburden at mines. However, very little of this nitrate is in the aqueous phase. It is more likely that the nitrate is formed from the dissociation of a chemical used in the beneficiation process, such as cyanide. This dissociation happens principally when the cyanide is being broken into its component parts through oxidation and biological action as part of reclamation. If fertilizers are used to assist in the regrowth of vegetation, small amounts of nitrate will be applied to the soils undergoing reclamation.
How could nitrate affect me?
Nitrate may be produced at mines in very low concentrations in water, typically less than 10 mg/l (as nitrogen), which is the drinking water criterion (a criterion designed especially to protect infants against the potential formation of methemoglobin). At higher concentrations, water with nitrate can be used for other purposes, such as supplemental irrigation, which makes use of the nitrate as a fertilizer. Nitrate is a normal component of the human diet. Over 85% of the intake comes from the natural nitrate content of vegetables such as beets, celery, lettuce, and spinach. Mines where nitrate can be produced in the aqueous environment will usually monitor water for this constituent.

VANADIUM

What is vanadium?
Vanadium (V) is a silvery-white metal that is easily molded. In nature, vanadium combines with other elements to form vanadium compounds. Small amounts of vanadium are naturally present in rocks, soils, water, and some deposits of iron ore and crude oil. Vanadium combines with other metals to form mixtures called alloys. For example, an alloy of vanadium and steel is unusually strong and resistant to heat and corrosion. Vanadium steel is used in engine and auto parts, springs, ball bearings, and high-speed tools. Vanadium compounds are used in ceramics, plastics, rubber, dyes, and as chemical catalysts.
How is vanadium released by electric utilities?
Trace amounts of vanadium are present in oil and coal. When electric utilities burn these fuels at their power plants, vanadium is released. Most of this vanadium is carried by particles of ash. Coal-burning power plants are equipped with devices to capture ash particles before they reach the air. Particle control devices typically capture more than 99% of the ash, so very little ash enters the air. Vanadium-carrying ash captured by these devices is usually sent to ash ponds or land disposal sites. Power plants reporting to the U.S. Environmental Protection Agency (EPA) released 290 tons of vanadium into the environment in 1998. This was about 59% of all the vanadium released by industries reporting to EPA that year.
Is vanadium also released by other sources?
Vanadium is released into the air by soils as they erode in wind and rain. It is released into water and soil by eroding rocks and ores. Vanadium released into the environment by human activities comes mainly from industrial boilers that burn oil or coal, chemical manufacturing plants, metal production facilities, and petroleum refineries. Industries reporting to EPA released 493 tons of vanadium into the environment in 1998. Most was released to the land.
What happens to vanadium after it is released by electric utilities?
Ash particles carrying vanadium settle to the ground after they are released into the air from power plants. Most vanadium reaches the ground through gravity and air turbulence. Only small amounts of vanadium dissolve in water and it does not seem to build up in the flesh of fish.
How might people be exposed to vanadium?
People are commonly exposed to small amounts of vanadium naturally present in the air they breathe, the water they drink, and the foods they eat. For example, cereals are a natural source of vanadium in people’s diets. Industrial workers may breathe vanadium dust or fumes.
What are the potential effects of vanadium on human health?
Breathing large amounts of vanadium can irritate the throat, lungs, and eyes, and long-term exposure can cause bronchitis. The body does not absorb vanadium easily through the digestive tract or skin. Thus, eating, drinking, or touching vanadium is unlikely to cause health problems. There are no studies of cancer in people exposed to vanadium.
How likely is it that utility releases pose a risk to human health?
It is unlikely that vanadium from power plants poses a significant risk to human health. EPA has not evaluated the potential health risks of breathing vanadium for people who live near power plans that burn oil or coal. Preliminary estimates from plants preparing to report vanadium releases to EPA indicate amounts of vanadium that are unlikely to cause significant health effects. Since airborne ash particles carrying vanadium are widely scattered before they settle to the ground, it is unlikely that ash from power plants significantly increases the amount of vanadium in soil, water, or food.
How is vanadium regulated?
EPA requires that 1000 pounds or more of vanadium be reported if it is spilled or released without a permit. The National Institute for Occupational Safety and Health has set limits on the amount of vanadium in workplace air. The Occupational Safety and Health Administration has set limits on the amount of vanadium pentoxide in workplace air.
Where can I get more information about vanadium?
The Agency for Toxic Substances and Disease Registry (ATSDR) has a fact sheet with answers to frequently asked health questions about vanadium. It is available through the ATSDR Information Center at 1-8000-447-1544 or on the Internet http://www.atsdr.cdc.gov/tfacts58.html

EPRI, 3412 Hillview Avenue, P.O. Box 10412, Palo Alto, California 94303 U.S.A.
800.313.EPRI or 650.855.2000 www.epri.com
© 2000 Electric Power Research Institute (EPRI), Inc.
All rights reserved. Electric Power Research Institute, and EPRI are registered service marks of the Electric Power Research Institute, Inc.

ZINC

What is zinc?
Zinc is a naturally occurring element and the third most used nonferrous metal (after aluminum and copper), of which the U.S. consumes more than one million metric tons annually.
Where does zinc come from?
Zinc occurs naturally in the earth, in the air and in the foods you eat. Most rocks and many minerals contain zinc in varying amounts and zinc exists naturally in air, water and soil. It is the second most common trace metal, after iron, naturally found in the body. Zinc is found in hundreds of products, including vitamins, cereals, cosmetics, pet foods, paints, fertilizers, tires, batteries, ointments, shampoos, soaps and pharmaceuticals.
How is zinc used?
Zinc is primarily used as a coating on iron and steel to protect against corrosion but zinc has many other uses such as:
- in brass and other alloys (zinc combined with copper makes brass)
- in automotive equipment and batteries (zinc can store six times as much energy per pound as other battery systems)
- household appliances, fittings, tools, toys
- in building and construction (zinc sheets used in architecture, for roofs or facades, on counters and on bar tops, have a maintenance-free life of over 60 years)
- in pharmaceuticals, medical equipment and cosmetics
- in tires and all rubber goods
- in fertilizers and animal feed and…
- zinc is common "cents." The U.S. penny is 98% zinc with a copper coating.
Does the mining industry release zinc into the environment?
Zinc is a naturally occurring element present in the earth’s crust. Due to natural erosion processes like the weathering and abrasion of rock, soils and sediments by wind and water, natural zinc is continuously being transported in the environment. Zinc is part of the rock “matrix” that is excavated, moved, and ultimately placed on the land during the mining process. It is this movement and placement of native rock that represents the majority of the reported zinc “releases” by the mining industry.
How could I be exposed to zinc and what are the health risks?
Zinc is a natural element found in the earth's crust and is used in many consumer products, dietary supplements and in the food we eat and the water we drink. Zinc is an essential nutrient required by the body and has a U.S. Government Recommended Daily Allowance of 15 milligrams for adults. Studies show that pregnant and lactating women need even more. Most adults, though, get only 9.9 milligrams a day, with women averaging 8.5. Zinc is essential to your health, boosting the immune system, helping cells to grow, regulating appetite and healing wounds. Zinc lozenges can even cut short the common

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