Mesothelioma Causes and Risk Factors
Exposure to asbestos fibers is the only proven cause of pleural and peritoneal mesothelioma. Patients are most often exposed to asbestos in occupational settings.
What Causes Mesothelioma?
Asbestos exposure is the only proven cause of mesothelioma. Asbestos is a naturally occurring mineral, originally admired for its unique insulating and fire retardant capabilities.
How Do People Get Exposed to Asbestos?
Occupational exposure is the most common type of exposure. Those working in industrial occupations frequently worked with materials containing asbestos. Electricians and shipyard workers were among those most commonly exposed to asbestos on the job.
Secondhand exposure occurred when those working in occupations using asbestos materials would inadvertently expose people at home. Asbestos in hair and on clothes was transferred to others not directly working with toxic materials.
Asbestos is a naturally occurring mineral. Those who lived near large deposits of asbestos may have been exposed through water run-off or mining projects. This form of exposure is rare.
What is Asbestos?
Asbestos is a naturally occurring mineral found in rock and other minerals, such as vermiculite. There are two main types of asbestos: serpentine and amphibole. Serpentine asbestos is generally less friable than amphibole asbestos.
These categories of asbestos are further broken down into subcategories, but they are all tiny, thin fibers that make up the mineral. The average human hair is approximately 1,200 times thicker than an asbestos fiber.
There are different types of asbestos:
- Serpentine asbestos – These wavy white fibers are able to be expelled by the body and therefore the least threatening. Serpentine asbestos fibers make up 95% of all asbestos found in building in the United States (subtypes: chrysotile)
- Amphibole asbestos – The body has a much harder time removing these fibers as they are rigid and needle-like. They can become lodged in the body and are the most deadly. (subtypes: amosite, tremolite, actinolite, anthphylite, and crocidolite)
How Does Mesothelioma Develop?
Exposure to asbestos is most likely to occur when materials containing asbestos are disturbed or loosened, releasing asbestos fibers into the air. Mesothelioma develops when:
- 1Airborne microscopic asbestos fibers are inhaled or ingested.
- 2The body attempts to remove these fibers but instead they become stuck in the protective lining surrounding the lungs, abdomen, or heart.
- 3The trapped fibers irritate the mesothelial cells, causing genetic mutations that develop into tumors over time.
How Mesothelioma Develops
These genetic mutations affect cell division and cause mesothelioma tumors. Mesothelioma may take between 20-50 years to show symptoms. Symptoms are often mistaken as a common cold or pneumonia with chest pain, breathing discomfort, or a consistent cough.
Men are more commonly diagnosed with mesothelioma than women at a ratio of 5 to 1. This is most likely because men have traditionally worked industrial jobs where asbestos was prevalent. Learn more about occupational asbestos exposure and how it causes mesothelioma in our free Mesothelioma Guide.
The cause of mesothelioma is generally attributed to asbestos exposure, but determining when the exposure occurred can be difficult. In some cases, patients may not even realize they have been exposed to asbestos at all.
Exposure can occur in unlikely places, including the household. However, when left undisturbed, most materials containing asbestos pose no immediate threat.
Remodeling work on older homes poses the risk of releasing asbestos fibers into the air by disturbing asbestos-containing building materials. Asbestos is not only found in homes, but also in cars. Brake pads, clutches, gaskets and insulation material can contain asbestos, especially in older cars.
The Environmental Protection Agency began requesting lists from American companies of their products containing asbestos in 1981, which eventually led to the Asbestos Information Act of 1988. Although asbestos is still used in the United States, this law requires manufacturers of asbestos products to submit detailed information on their products to the EPA.
Regulations regarding asbestos also categorize different types of asbestos into friable and non-friable asbestos. Friability is simply how easily a substance crumbles or breaks apart. Non-friable asbestos-containing materials are generally considered as relatively safe (when undisturbed). However, friable asbestos-containing materials are much more dangerous. non-friable asbestos-containing materials are regulated in the United States; however, any asbestos-containing material can become friable.
Occupational hazards are the most common cause of asbestos exposure. People employed in shipyards, automotive jobs and the military have an especially high risk of developing mesothelioma. These people are at a higher risk of asbestos exposure because of the materials they worked with.
Some common industrial materials containing asbestos are:
- Roofing and flooring materials
- Brake pads
- Pipes and pipe fittings
- Electrical wiring
Asbestos production increased substantially during World War II. The increased production of ships, aircraft and other vehicles was a major reason why asbestos became so commonly used. Its insulation and fire resistance properties made asbestos a convenient material for most industrial applications. This put military veterans and those in industrial occupations at risk.
The companies responsible for the increased use of asbestos containing materials knew about the risks associated with asbestos. Many of these companies have filed bankruptcy and set up trust funds to handle the claims against them. If you are a victim of occupational exposure, you may be entitled to compensation from one or more of these asbestos trust funds.
Some mesothelioma victims do not remember where they were exposed. Others may not even realize they were exposed. It is possible these individuals had secondhand exposure to asbestos.
Spouses of construction or factory workers are the most common example of secondary exposure. Many workers returned home with asbestos fibers on their clothes, skin, and in their hair. Secondary exposure occurred from contact with the directly-exposed spouse and even from doing laundry.
Secondary asbestos exposure has occurred in occupational environments as well. Any workers who spent time around employees exposed to asbestos could be at risk.
Lastly, secondary asbestos exposure has occurred in communities where asbestos was released into the air from nearby factories manufacturing asbestos materials, shipyards, mills, mines, and building demolitions.
Libby, Montana is an example of mining leading to secondary exposure. W.R. Grace and Company took over the vermiculite ore mine in Libby in 1963. Despite knowing the dangers of asbestos, the mine operated without regulations until 1990. The EPA has spent over $450 million on the cleanup, and at least 300 deaths have been attributed to this one location. The Affordable Care Act offers financial assistance for mesothelioma victims and public health emergencies like Libby.