Sunday, October 25, 2009

What is Asbestos?



A common misconception on the part of many individuals, however, is that asbestos is a hazardous man-made substance, conjured up in factories around the world for commercial use. The truth is, however, that asbestos is a naturally-occurring mineral that can be found in hundreds of countries on just about every continent. As a matter of fact, asbestos is still mined in several of these countries, including Canada and Russia. Other countries have outlawed the mining of asbestos.


Asbestos is a highly-fibrous mineral with long, thin, separable fibers. The thin fibers can be spun and woven together, and possess valuable heat-resistant properties that make asbestos suitable for insulation and other such products. Indeed, for decades, asbestos was the material of choice for many industries that were manufacturing products for which heat resistance, low electrical conductivity, flexibility, and high tensile strength were essential factors. Today, there are other alternatives.

There are two kinds of asbestos. The serpentine variety is curly. Chrysotile asbestos, most commonly used for industrial purposes, is from the serpentine family. Other asbestos fibers, from the amphibole family, are very straight and needle-like. Amosite, crocidolite, tremolite, actinolite, and anthophyllite are amphibole asbestos varieties.

Currently, chrysotile asbestos is the only type mined on a wide-scale though a handful of countries continue to mine other forms. However, worldwide outrage about the use of dangerous asbestos has forced many countries to reconsider their position on mining.

Contrary to what many people believe, asbestos is not and has never been banned in the United States. In 1976, Congress passed a law to regulate toxic substances (known as the Toxic Substances Control Act) but a total ban was not suggested. In 1989, the Environmental Protection Agency finalized regulations to ban asbestos under the aforementioned act, but two years later, a New Orleans circuit court of appeal overturned the regulation. The result was that new uses of the dangerous mineral were banned but old ones remained.


Many other industrialized nations have banned asbestos including the European Union and a handful of other countries, such as Chile, Croatia, Australia, Argentina, and Saudi Arabia. Several countries, especially those who continue to make money from the mining of asbestos, consistently fight against asbestos bans.

A few current U.S. senators, with the assistance of asbestos watchdog groups, hope to encourage the government to reconsider a ban on all asbestos products. A new bill, called the "Ban Asbestos in America Act of 2007" (S.742), was introduced by Senator Patty Murray on March 1, 2007.

Mesothelioma is sometimes referred to asbestos cancer. It is referred to this because the only known cause of mesothelioma is exposure to asbestos. Asbestos exposure causes mesothelioma in different ways depending on the variety of the malignancy.


Pleural Mesothelioma and Asbestos

Pleural mesothelioma, the most common variety, is caused by inhaled asbestos fibers which lodge themselves in the pleural lining of the lungs. Asbestos fibers, which are microscopic but durable, then irritate the inner tissue, causing the growth of harmful scar tissue and eventually mesothelioma.

Peritoneal Mesothelioma and Asbestos

Peritoneal mesothelioma is less common and doctors have not exacted relationship between the asbestos exposure and the malignancy. However, nearly all peritoneal mesothelioma patients have a history of asbestos exposure. Peritoneal mesothelioma occurs in the lining of the abdominal cavity, near the digestive tract. Doctors surmise that ingested asbestos fibers lodge in the outer tissue of the organs and cause a similar inflammation as in the pleura.

Pericardial Mesothelioma and Asbestos

Pericardial mesothelioma occurs in the lining of the heart and is extremely rare. Like peritoneal mesothelioma, very little is known about the relationship between the malignancy and asbestos exposure but nearly all patients have asbestos exposure history. Physicians surmise that because the cancer occurs in the heart’s lining, the asbestos fibers may impact the heart through the bloodstream.

Lung Cancer and Asbestos

Asbestos has also been linked to cancers of the lung, as opposed to the pleural lining of the lungs. These are likely the result of malfunction caused due the exposure and inhalation of asbestos fibers, which can also cause chronic respiratory conditions such as asbestosis.

No comments:

Post a Comment