Asbestos cancer is a malignant tumor caused by exposure to asbestos fibers. Asbestos exposure is most commonly associated with mesothelioma and lung cancer. Mesothelioma is a rare cancer affecting the lining of the lungs, heart, and abdomen, while traditional lung cancer occurs in the tissue of the lung’s lobes..
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.
What is Asbestos?
For most individuals, especially those born in the last 40 years, the mention of asbestos conjures up thoughts of a dangerous substance that's sickened many people and caused myriad deaths around the world. That's an accurate description.
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.
Why is Asbestos a Health Concern?
Studies estimate that approximately 3,000 different types of commercial products include asbestos. In and of itself, the mineral is not harmful, as long as it's intact. However, when the asbestos in these products is damaged and the fibers become airborne, concerns begin to arise.
"Friable" asbestos - that which is dry and can be easily crumbled with the hand - is the culprit. Such asbestos is more likely to release fibers into the air. Spray-applied asbestos fireproofing, which was used in millions of buildings throughout the world, is of the friable variety. However, some non-friable asbestos can also release airborne fibers, particularly when sanded, chopped, hammered, cut, or otherwise manipulated. That's why, when demolishing a building that contains asbestos, proper removal and disposal in a designated asbestos landfill is essential before the building is torn down.
Why are Airborne Fibers Dangerous?
Inhaled asbestos fibers remain in the body and cannot be expelled. Because of this, the fibers can easily penetrate body tissues and may deposit themselves in airways and in the lung tissue. The more you're exposed, the more likely you might develop an asbestos-related disease. Most people exposed to asbestos on a very casual basis probably will not develop such a disease.
Once the fibers are lodged in the body, they will cause inflammation which may eventually result in the formation of cancerous tumors, particularly on the mesothelium - the lining of the lungs. Other affected areas may include the peritoneum - the lining of the abdomen - and the pericardium - the lining around the heart. There are various type of mesothelioma treatment options for each type.
With some recent exceptions found in workers at the World Trade Center disaster, asbestos-related diseases, such as pleural mesothelioma, usually surface several decades after exposure. That's why current cases of mesothelioma and other asbestos-related diseases involve many individuals who were employed in shipyards during World War II, performing jobs that exposed them to friable asbestos on a daily basis. Shipyard workers are among those most affected by aggressive asbestos cancer.
Is Asbestos Banned?
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.
- Agency for Toxic Substances and Disease Registryhttp://www.atsdr.cdc.gov/NEWS/asbestosexposure2.html
- American Cancer Society.http://www.cancer.org/docroot/CRI/content/
- National Institute for Occupational Safety and Healthhttp://www.cdc.gov/niosh/topics/asbestos/
Last modified: April 14, 2011.