Causes of Mesothelioma
For many, cancer may seem like a mystery illness. Often, no one knows why certain people develop it and others don't. Everyone understands, of course, that smokers have a higher chance of developing lung cancer and other cancers caused by their smoking habit. Diets that are high in fat and other nutritional issues may also have a bearing on whether or not an individual develops cancer during their lifetime.
For mesothelioma patients, the cause has become quite clear. Up to 85% of all diagnosed cases of mesothelioma can be definitively linked to exposure to asbestos. For decades, concerned doctors and research scientists speculated about the dangers of asbestos and warned industries to discontinue its use, but a conclusive link wasn't actually made until 1999, when it was too late for the millions around the world who had already suffered prolonged exposure to the dangerous mineral.
How Does Asbestos Make You Sick?
Asbestos is a naturally-occurring mineral that possesses excellent insulating and heat-shielding properties. Because of this, it has been used for decades - even centuries - in a variety of products, including building materials like insulation, gaskets, floor and ceiling tiles, and drywall tape, as well as in automotive products such as brake pads and shoes and clutch plates.
Asbestos is not dangerous when left undisturbed. As a matter of fact, scientists estimate that asbestos occurs naturally in our air and drinking water and that everyone breathes in the mineral at some time or another. However, when asbestos is damaged and becomes "friable" - soft and weak - it is more easily airborne, and hence, inhalation can occur more easily.
Individuals who worked with asbestos that was cut, crushed, sanded, torn, or otherwise manipulated were prone to inhaling these dangerous fibers. Prior to the asbestos warnings of the 1970s, individuals who worked with asbestos were given little or no protective gear, even though it has been proven that experts have known about the dangers of asbestos for more than a century and warned industries of the risks.
Usually, those exposed to asbestos on a regular basis do not get sick immediately. As a matter of fact, asbestos diseases often do not appear for 20-50 years after exposure. However, a handful of workers who were first responders at the World Trade Center disaster in 2001 have already died of mesothelioma due to extreme exposure to the material.
Asbestos fibers that are breathed into the lungs cannot be expelled, so they remain there, embedding themselves in the lining of the lung (the mesothelium) and causing inflammation. Cancerous tumors may develop decades later and require very harsh mesothelioma treatment.
Who Is at Risk?
Individuals who have worked many years at particular jobs where asbestos was in plentiful use are most at risk for developing mesothelioma or any other sort of asbestos-related disease.
One of the highest incidences of mesothelioma is among shipyard workers who were employed during the peak years of World War II, not only in America but also in other countries. Because shipyards often performed overhauls on war ships, workers were exposed to large amounts of friable asbestos and inhaled the mineral on a regular basis for long hours at a time. Shipyard workers that were consistently at risk include:
Other professions that have also reported high numbers of cases of mesothelioma are:
- Auto mechanics
- Auto inspectors
- Iron Workers
- Power Plant Workers
- Railroad Workers
What's Being Done to Stop Exposure?
After the U.S. government issued warnings in the mid 1970s as to the dangers of asbestos, employers began to provide their workers with protective gear essential to maintaining good health while working with the mineral. Many countries chose to ban asbestos altogether.
In 1989, the US Environmental Protection Agency (EPA) issued a final rule banning most asbestos-containing products. In 1991, this regulation was overturned by the Fifth Circuit Court of Appeals. That means some products still contain asbestos, but laws say they must be clearly labeled. Some countries still mine and use asbestos on a regular basis and export the mineral to other countries that have not yet issued a ban.
Hopefully, new cases of exposure should be lessening, but that won't be evident until the current rash of mesothelioma cases has peaked and is passed. Due to mesothelioma's long latency period, most of today's diagnosed cases involve individuals who were exposed prior to the 1970s.
The Hidden Risks
While most cases of mesothelioma involve men and women who were directly exposed to asbestos, more and more cases of second-hand exposure are coming to light. Family members of workers who brought asbestos home on their clothing have contracted the disease and are now wondering who's responsible.
In addition, communities where asbestos was mined or asbestos-products were produced are gradually discovering cases of mesothelioma among those who never had direct contact with the mineral or any products containing it. In the case of Libby, Montana, for instance, hundreds have already died of mesothelioma due to the fact that asbestos was mined there for many years.
- American Cancer Society. http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_malignant_mesothelioma_29.asp?rnav=cri
- National Institute for Occupational Safety and Health http://www.cdc.gov/niosh/topics/asbestos/
- National Cancer Institute. http://www.cancer.gov/cancertopics/factsheet/Risk/asbestos
Last modified: February 15, 2010.