Asbestos is a group of minerals that occur naturally in the environment and can be mined. The extraction and use of asbestos dates back to Ancient Egypt. Typically, asbestos is found in these rock types: serpentines; some mafic rocks (which have higher amounts of heavier elements); altered ultramafic rock; metamorphosed dolostones; metamorphosed iron formations; alkalic intrusions and carbonatites. Varying amounts of asbestos can be found in these rocks. When rocks are broken or crushed, the asbestos can be extracted.
The mining process that was used in the United States involved open pit extraction and then milling. In a period extending from the late 1960’s to the early 1970’s, asbestos mining peaked in the United States, with over 299 million pounds mined each year. By 1987, production has diminished to 112 million pounds annually. In 1989, when the Environmental Protection Agency ban on most asbestos use was passed, 13.2 million pounds were mined.
Asbestos is found across the globe, including in the United States, South Africa, Canada and areas in the former Soviet Union. Asbestos is found in 20 of the United States and has been mined in 17 of these states, including the Appalachian region, California and Oregon. At this point, chrysotile is the most commonly mined and most commonly used form of asbestos. It is mined in Quebec, British Columbia, Russia, Italy, America, Greece and Cyprus (3). In 2005, Russia accounted for 40% of the asbestos produced in the world, with China and Kazakhstan also producing significant amounts. Tremolite asbestos is mined in small amounts in India. Asbestos use continues in developing countries, especially those like India and China where a great deal of growth is occurring. An advocacy organization called the International Ban Asbestos Secretariat is working to pass bans on asbestos in more countries across the globe.
Asbestos can also be found in demolition sites. For example, a great deal of asbestos was released into the atmosphere on September 11, 2001, when the World Trade Centers collapsed. Asbestos was used in the construction of the North Tower; when this tower fell, asbestos particles became airborne and were inhaledand ingested by rescue, recovery and clean up workers. Based on this exposure, these individuals are advised to closely monitor their respiratory health for signs and symptoms of any conditions associated with asbestos exposure, such as the asbestos cancer known as mesothelioma.
One of the largest and oldest vermiculite mines associated with asbestos was the W.R. Grace Mine in Libby, Montana. Vermiculite, a common mineral, was mined here until it was discovered that it was contaminated with asbestos. The mine’s operations were shut down in 1990. However, the impact of this asbestos-laced vermiculite was felt for many more years. The vermiculite was processed at a site in Salt Lake City, Utah, and it was not until 2004 that this site was officially cleaned up to remove all asbestos. Vermiculite is still mined in South Carolina, Virginia, and South Africa. The Environmental Protection Agency has issued guidelines to minimize the risks of using vermiculite.
Asbestos can also be found naturally in soil and rock. For example, El Dorado County, California, and Fairfax County, Virginia, have been found to contain a significant amount of asbestos in their soils. Individuals can be exposed to asbestos in the natural environment, during activities such as gardening, shoveling dirt, or riding bikes or traveling over unpaved surfaces.
Those who worked in asbestos mines or live in areas were asbestos naturally occurs came into contact with asbestos in the natural environment. However, most people were exposed to asbestos in the man made environment, as it was used in industrial and construction processes and in thousands of products.
Industries that involve exposure to asbestos include: mining; chemical plants; oil refineries; power plants; shipyards; aluminum plants; steel mills. Teachers, weavers, building inspectors and crane operators may have also come into contact with asbestos through work. Because asbestos was also used as a building material for many years, those who lived, worked or went to school in buildings with asbestos content may have also been exposed to it.
Asbestos was also used to make many commonly-used products; one study found that it was used in over 3,000 products. These include: fireproofing substances; roofing materials; siding; bricks; emergency generators; insulation, including sprayed insulation; vinyl flooring; drywall materials; cement panels; piping; talc-based products such as baby powder; wire insulation; fertilizers containing vermiculite; and certain textiles. Small appliances, including toasters, coffee pots, and hair dryers, also contained asbestos for many years.
Understanding where asbestos is found is important in avoiding contact and assessing one’s risk. It can take anywhere from 15 to 50 years after exposure occurs for symptoms to begin surfacing and for health to be impacted. Those who were exposed to asbestos are advised to monitor their health for signs and symptoms of the conditions most commonly associated with asbestos exposure, which include: mesothelioma, lung cancer, asbestosis, and pleural effusions. Some common symptoms to respiratory conditions include shortness of breath, coughing up blood, fatigue and weight loss.
One of the most severe risks of asbestos is malignant mesothelioma, a rare form of cancer that grows on the mesothelium, a membrane that covers many of the body’s internal organs including the lungs and heart. There are four main types of mesothelioma, depending on the primary site of the tumor: pleural mesothelioma; peritoneal mesothelioma; pericardial mesothelioma; and the extremely rare testicular mesothelioma, which develops in the tunica vaginalis or the membrane that surrounds the testicle.
The disease can be treated with chemotherapy, surgery, radiation and experimental therapies such as immunotherapy. These treatments may slow the progress of the disease and reduce symptoms, such as shortness of breath, to increase comfort. While research on new treatments are being pursued, mesothelioma is not yet considered curable.