Asbestos is a naturally-occuring fibrous mineral of metamorpic hydrous magnesium silicate. The term "metamorphic" is used to describe a process of extreme heat and pressure which creates specific secondary patterns of minerals with new chemical and/or physical properties. As the primary rock is heated and recooled, silicate crystals align in long rows of mineral fibers, which easily separate into tiny shards thinner than a human hair. Asbestos fibers are not a health risk as long as they are undisturbed. However, when asbestos is undergoes natural weathering, or is mined and processed, the microscopic particles waft into the air and cause disease if they are inhaled.

Asbestosis occurs when an inhaled asbestos particle irritates the body's natural defence mechanisms, causing inflammation and scarring which eventually restricts lung function. Mesothelioma is a malignant tumor of the membranes surrounding the heart, lungs and abdominal cavity. Asbestos can also cause cancer of the mouth, throat, esophagus, larynx, stomach, lung and lymphoid tissue.

Asbestos exposure can also cause non-fatal illnesses such as asbestos warts, caused when asbestos fibers are lodged in the skin, causing lumps of scar tissue to form around the irritant in the same manner as they do in the lungs to cause asbestosis; pleural plaques, discrete, sometimes calcified fibrous lesions which can be seen on X-rays but are too small to cause breathing impairment; and diffuse pleural thickening, which can cause breathing impairment if it is extensive.

Due to its fire resistant properties, asbestos has been used historically for household and industrial purposes. It has been found woven into burial cloths in ancient Egypt, and Charlemagne reportedly had a tablecloth made of asbestos which he would throw into a fire to clean.

In World War II asbestos was considered so important by the War Department that it was considered a strategic material, and many American workers were exposed in the World War II boom in shipbuilding. After the war, it was widely used in the construction industry.

In modern Western society, it was used for such diverse purposes as lamp wicks, brake shoes, oven insulation, electrical hotplate wiring and home insulation, roofing and flooring. For instance, some kinds of vermiculite used in home insulation into the 1970s contained asbestos. The EPA banned this product in 1977.

When a home owner discovers asbestos in an old home, it should not be a cause for immediate panic. If the asbestos looks intact and is not pulverized, it is best to leave it alone. However, because of legal liability, schools and businesses containing asbestos usually must undergo a costly removal process, hazardous in itself because disturbing the stable asbestos product causes fibers to fill the air. Special equipment must be used to insure that the removal process does not cause health problems where non existed before.

Most industrialized nations have reduced or banned the use of asbestos for at least 30 years and now use fiberglass or woven ceramic fiber as a substitute, but since asbestos-caused disease has a latency period of up to 50 years, patients are still presenting with these illness today. Every year in America, approximately 3000 new cases of mesothelioma are diagnosed, and 550 deaths occurs due to asbestosis. According to the March 1991 Report of the Judicial Conference Ad Hoc Committee on Asbestos Litigation, asbestos exposure has caused the deaths of approximately 200,000 to 265,000 Americans.

Asbestos use peaked in the United States in 1973, when 1 million tons of the material were used. The EPA attempted to institute a complete legal ban on the use of asbestos products in 1989; however, this ban was largely eviscerated by the US 5th Circuit Court of Appeals in 1991, and some restricted use of asbestos, albeit in fewer products than than before, resumed. Therefor, even today some workers are being exposed to this toxic material.

Asbestos is a serious continuing concern to the Environmental Protection Agency, and their website has detailed information on asbestos and its removal.

Concerns about the health risks of asbestos exposure date back to 1898, when the Chief Inspector of Factories of the United Kingdom reported to Parliament in his Annual Report about the "evil effects of asbestos dust". He noted that the "sharp, glass like nature of the particles" when allowed to remain suspended in the air, "have been found to be injurious, as might have been expected". In 1906 a British Parliamentary Commission confirmed the first cases of asbestos-related deaths in Bristish factories and called for improved ventilation and other safety measures. In 1918 an American insurance company produced a study showing premature deaths in the asbestos industry in the United States and in 1926 the Massachusetts Industrial Accidents Board processed the first successful compensation claim by a sick asbestos worker.

Today, lawsuits claiming compensation for asbestos-related illnesses are a growth industry in the legal profession. An internet search of "mesothelioma lawyer" yields 1,910,000 results. The original manufacturers of asbestos products have long since been driven into Chapter 11 bankruptcy; plaintiffs have now turned to suing corporations with peripheral connections to asbestos products. More than 70 American corporations have filed Chapter 11 bankruptcy in due to asbestos liability claims.

Since the 1970's, approximateley 6% of all lawsuits filed in American courts have been asbestos-related. The lawsuits now facing the courts have been described as "an elephantine mass" by the US Supreme Court, and are expected to cost between 200 to 275 billion dollars to settle. Asbestos liability is one of the largest issues facing the global insurance industry today.

Most epidemiological studies expected the number of lawsuits to peak in the 1990s, but this has not occurred, either because of the long latency period of asbestos-related diseases, or because legal action is becoming more popular among asbestos-exposed members of the public due to high-profile legal cases and widespread advertising by attorneys who specialize in such cases.

Many complaints have been made by representatives of industries facing lawsuits and the insurance companies who will be expected to pay them that the asbestos-lawsuit industry is rife with fraud, with less that half of all payouts reaching the plaintiffs. Aggressive, ambulance-chasing lawyers are said to exaggerate medical disability and coach clients on their testimony.

The group of plaintiffs includes not only ill people, but also those who have merely have a history of asbestos exposure and want compensation for potential future health risks. According to the American Academy of Acturaries Mass Tort Work Group, more than 100 million Americans have been exposed to asbestos in their workplace during the past century.