
TRI/Right-To-Know Communications Handbook CHEMICAL FACT SHEETS Arsenic Chromium Copper Cyanide Lead Manganese Mercury Nickel Selenium Silver Zinc Section 5 - page 1 TRI/Right-To-Know Communications Handbook Frequently Asked Questions & Answers about ARSENIC What Is Arsenic? Arsenic mineral is a gray, brittle, metal-like substance that is a natural part of the earth's soil and rocks. It is not commonly found in its elemental form, but rather as an arsenic compound associated with other naturally occurring elements and compounds. Arsenic compounds are present in many kinds of rocks, especially in ores that contain copper or lead. Arsenic levels in soil vary from one part arsenic per million parts of soil up to about 100 ppm. It can be released into the environment by natural sources such as erosion from mineral deposits and volcanic eruptions. Arsenic is found in water, both above-ground and underground. Arsenic can also be released into the air in dust from the soil. Approximately half of the arsenic released to the air comes from soil dust. The other half comes from human activity such as industrial processes. Roughly 75% of human-induced arsenic compound emissions result from the processing of metal to ore. Human activities can release arsenic into the soil, air, and water. ¨ Soil releases: Industrial processes account for nearly 95% of all arsenic released into land. Arsenic is also released into the soil as a result of pesticide application, solid waste disposal, and sewage sludge. ¨ Air releases: About half of the arsenic released into the air (about 8,500 tons each year) comes from natural sources like volcanic eruptions and forest fires. Airborne arsenic releases also come from various industrial processes, agricultural products, and electricity production. ¨ Water releases: Most of the arsenic released into the water results from natural, weather-related processes. Does The Mining Industry Release Arsenic Into The Environment? In addition to metal ore processing and the production of metal, very small amounts of arsenic are naturally present in rocks and soils. These compounds may be released into the environment by moving these materials as well as by the natural erosion process. Arsenic is also present in coal used to generate electricity. When coal is burned, ash is produced which contains most of the naturally occurring arsenic. More than 99% of the ash is collected and is either sent to specially-designed ash ponds or disposal sites or recycled into commercial products. How Could Arsenic Affect Me? Arsenic's naturally low-level presence in the environment and routine arsenic compound releases discussed here generally are considered to be a low risk to public health. Interestingly, very small amounts of arsenic in people's diets may actually improve health. What Does EPA Say? The U.S. Environmental Protection Agency (EPA) acknowledges that arsenic is a naturally occurring substance that will always be present in the environment. Nonetheless, EPA monitors the amount of arsenic in drinking water and has acted to curb manmade arsenic releases by curtailing the use of arsenic in pesticides. EPA acknowledges that low levels of arsenic will be present in soil, food, water, and air regardless of whether it is produced by human activities. Section 5 - page 2 TRI/Right-To-Know Communications Handbook Environmental Health Center A Division of the National Safety Council 1025 Connecticut Avenue, NW, Suite 1200, Washington, DC 20036 (202) 293-2270 (tel); (202) 293-0032 (fax) Arsenic (As) Chemical Backgrounder Description: Arsenic (C.A.S. 7440-38-2) is a naturally occurring element in the earth's crust. Pure arsenic is a gray-colored metal, but is rare in the environment. Arsenic is usually found combined with one or more other elements such as oxygen, chlorine, and sulfur. In combination, such arsenic is referred to as inorganic arsenic. Arsenic combined with carbon and hydrogen is referred to as organic arsenic. The organic forms are usually less toxic than the inorganic forms. Arsenic is produced primarily as a by-product from the operation of copper and lead smelters. The major uses of arsenic in the U.S. are as wood preservatives (74 percent of all arsenic), agricultural products (19 percent), glass (3 percent), nonferrous alloys (2 percent), and other uses (2 percent). Chemical and physical properties: Synonyms for arsenic are arsenic-75, metallic arsenic, arsenic black, arsenicals, and colloidal arsenic. The inorganic arsenic compounds are solids at normal temperatures and are not likely to volatilize. In water, they range from quite soluble (sodium arsenite and arsenic acid) to practically insoluble (arsenic trisulfide). Some organic arsenic compounds are gases or low-boiling liquids at normal temperatures. Poisonous gas is produced by arsenic in a fire. Arsenic near acid or acid mist can release a very deadly gas, arsine. Twenty-one arsenic compounds are considered to be of concern because of their toxicity and/or presence in the environment. Health effects: Large doses of inorganic arsenic can cause death. Arsenic is a known poison and a known carcinogen that has been shown to cause skin and lung cancer. It also may damage a developing fetus and should be handled as a potential teratogenic agent (causing developmental malformations), as some arsenic compounds are known teratogens. Oral exposure to inorganic arsenic can cause digestive tract pain, nausea, vomiting, diarrhea, decreased production of red and white blood cells, abnormal heart function, blood vessel damage, liver and/or kidney injury, and impaired nerve function, causing a "pins and needles" effect in the feet and hands. Oral exposure to inorganic arsenic can also cause a pattern of skin abnormalities, including the appearance of dark and light spots on the skin, and small "corns" on the palms, soles, and trunk, which may ultimately progress to skin cancer. In addition, arsenic ingestion is reported to increase the risk of cancer inside the body, especially in the liver, bladder, kidney, and lung. Section 5 - page 3 TRI/Right-To-Know Communications Handbook Environmental Health Center A Division of the National Safety Council Arsenic (As) Chemical Backgrounder (continued) Health effects: (continued) Skin contact with arsenic can cause burning, itching and a rash. Breathing arsenic can irritate the nose and throat; eye contact can cause red, watery eyes and irritation. Long-term exposure can cause an ulcer or hole in the "bone" dividing the inner nose, hoarseness, and sore eyes. Populations relying on groundwater or surface water near geologic or man-made sources of arsenic may receive higher than typical exposures. These areas include industrialized areas and areas where large quantities of arsenic are disposed of in landfills, as in parts of Pennsylvania, southern New York, Ohio, Indiana, and Washington; areas of high historical pesticide use, with soil low in available ferrous and aluminum hydroxides; and areas of high natural levels of arsenic-containing mineral deposits, as in the western U.S. Populations in the area of copper and other types of metal smelters may be exposed to above-average levels of arsenic both through the air and as a result of atmospheric deposition in soil and water. Individuals with protein-poor diets or choline (of the Vitamin B complex) deficiency may be more sensitive to arsenic than the general population. Economics: No arsenic producers currently operate in the U.S., and all raw materials for production of arsenic-containing products must be imported. Until 1985, arsenic trioxide was produced in the U.S. only at the ASARCO smelter in Tacoma, Washington. Annual production was 7,300 metric tons (16 million pounds) in 1983, but production decreased to 2,200 metric tons (4.8 million pounds) in 1985. In 1979, the U.S. imported 8,940 metric tons (19.5 million pounds) of arsenic in the form of arsenic metal or inorganic arsenic compounds. By 1985, imports had risen to 19,000 metric tons (41.5 million pounds) and increased to nearly 28,000 metric tons (61.2 million pounds) in 1986 after domestic production ceased. Regulation: The Occupational Safety and Health Administration issues permissible exposure limits for inorganic arsenic; the Food and Drug Administration issues permissible levels of arsenic in muscle meats, edible meat by-products, and eggs. EPA offices overseeing regulations and guidelines applicable to arsenic include Air Quality Planning and Standards, under National Emissions Standards for Hazardous Air Pollutants; Water Regulations and Standards, under the National Pollutant Discharge Elimination System; Drinking Water; Emergency and Remedial Response; Solid Waste; and Pesticide Programs. Under the Emergency Planning and Community Right-to-Know Act of 1986, releases of more than one pound of arsenic and arsenic compounds into the air, water, or land must be reported annually and entered into the national Toxic Release Inventory (TRI) data base. Total emissions of arsenic in 1987 were reported to be 88,000 pounds, and of arsenic compounds, 130,000 pounds. Arsenic was released in 24 states, the top three being Texas (52,858 pounds), South Carolina (9,173 pounds), and Arizona (8,770 pounds). Arsenic compounds were released in 30 states, the top three being Montana (51,000 pounds), Arizona (4,100 pounds), and Texas (4,094 pounds). Section 5 - page 4 TRI/Right-To-Know Communications Handbook Frequently Asked Questions & Answers about 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.
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