Mesothelioma Causes

Mesothelioma is a form of cancer that is almost always caused by exposure to asbestos. It occurs when malignant cells develop in the lining of the chest cavity, abdominal cavity, or the cavity around the heart. Mesothelial cells cover the outer surface of most of the body’s internal organs. The tissue formed by these cells is called mesothelium. The mesothelium acts as a protective layer for the organs by producing a special lubricating fluid that allows organs to shift. This fluid is especially crucial to the lungs, as it allows the lungs to expand and contract inside the chest cavity. The mesothelium of the chest is called the pleura and the mesothelium of the abdomen is called the peritoneum. The mesothelium that lines the heart is called the pericardium.

Mesothelioma, a cancer affecting the thin layer of tissue covering most internal organs, is overwhelmingly caused by exposure to asbestos. Asbestos is a naturally occurring mineral with long, thin fibrous crystals derived from metamorphic rocks. Asbestos fibers are soft and pliable to the touch and capable of withstanding very high temperatures. They are also very strong and can make products more durable. When left intact and undisturbed, asbestos fibers pose no health risk. Asbestos, was used extensively in construction, manufacturing, and various industrial applications.  Environments such as aging infrastructure or industrial settings are common sites of exposure, particularly impacting workers involved with asbestos-laden materials like insulation or drywall.

Asbestos can be found in products such as joint compound (mud), gaskets, auto brakes, rope, plaster, and insulation. Anyone who has worked with or around products containing asbestos is at risk for developing an asbestos-related disease like mesothelioma, asbestosis, or lung cancer.

Prolonged exposure to raw asbestos or to materials containing asbestos can lead to terminal illness. However, many individuals have been diagnosed with mesothelioma years after a brief but intense exposure to asbestos—for example, during a summer job. There are also many documented cases of mesothelioma resulting from second-hand exposure to asbestos carried home on a worker’s clothing. Wives who regularly launder their husband’s clothes and children who encounter dust on a family member’s clothing are at heightened risk.

The linkage between occupational exposure to asbestos and the incidence of diseases like asbestosis and mesothelioma is significant, with research indicating that approximately 80% of mesothelioma cases can be traced back to asbestos. The World Health Organization highlights asbestos as a leading cause of occupational cancer deaths, underscoring the mineral’s hazardous nature. 

Pathway from Asbestos Exposure to Mesothelioma

There is a latency period ranging from 15 to 50 years between initial exposure to asbestos and the development of this deadly disease. For many who worked in shipyards, power plants, and other industries that used asbestos in their manufacturing process in the 1950s, 1960s, and 1970s, symptoms of this disease are just beginning to surface now.

Exposure can be direct (primary), such as through work-related activities, or indirect (secondary), such as through contact with contaminated clothing. Secondary exposure is particularly concerning for family members of individuals who work with asbestos.

Studies suggest a multi-step process by which asbestos fibers cause mesothelioma:

• Asbestos fibers are breathed in or swallowed.
• These fibers lodge in the mesothelium, a protective lining of the lungs and other organs.
• The presence of fibers leads to inflammation and damage to cells.
• Cellular damage progresses to cancerous transformations in the mesothelium, resulting in mesothelioma.

In addition to causing inflammation and scarring, asbestos has been shown to directly damage DNA, increasing the risk of cancer development.

DNA Damage and Cancer Induction by Asbestos

The carcinogenic effects of asbestos include:

• Hindering normal cell division, leading to genetic mutations.
• Directly interacting with DNA and altering its regulatory functions.
• Inducing chronic inflammation, which exacerbates DNA damage over time.
• Such cumulative genetic damage is a precursor to various cancers, including mesothelioma.

The type of mesothelioma that develops depends on where the asbestos fibers accumulate and the extent of the tissue and DNA damage, with the disease manifesting in forms such as pleural, peritoneal, pericardial, or testicular mesothelioma.

Strategies for Reducing Mesothelioma Risk

The most effective strategy for mesothelioma prevention is avoiding asbestos exposure. Regulations introduced by the EPA in the 1980s aimed to reduce exposure risks, but without a total ban in the U.S., potential for exposure remains. Key preventive actions include identifying potential asbestos sources, following occupational safety guidelines, and employing professionals for asbestos management in older buildings.

Individuals with potential asbestos exposure should seek medical advice for risk evaluation and monitoring. Early detection efforts focus on identifying symptoms indicative of mesothelioma, facilitating prompt diagnosis and treatment. Such measures can significantly influence the effectiveness of treatment and overall prognosis for those diagnosed with this condition.

Second-Hand Asbestos Exposure

Second-hand exposure to asbestos is a less discussed but significant risk factor. Those living near asbestos-related facilities, such as the Durez plant in Niagara County, may recall dust settling around their homes. This seemingly innocuous dust was composed of asbestos fibers blown into the neighborhood. Individuals exposed to these airborne fibers face an elevated risk of developing mesothelioma.

Furthermore, handling the clothing of loved ones who worked in asbestos-contaminated environments can lead to inadvertent inhalation of asbestos fibers. This practice unknowingly places individuals at risk of mesothelioma. Exposure to asbestos is the primary cause of mesothelioma.  The primary mode of exposure is inhalation, with ingestion and second-hand exposure serving as additional, less common, pathways. Vigilance and awareness are essential, especially for those with a history of asbestos exposure. Medical consultation and routine screening are crucial for early detection and managing the risks associated with this devastating disease.

Asbestos and Mesothelioma

The direct link between asbestos exposure and mesothelioma underscores the importance of awareness, occupational safety, and preventive practices. By understanding the mechanisms of asbestos-induced carcinogenesis and adopting measures to minimize exposure and its risks, it is possible to mitigate the prevalence and impact of mesothelioma. Health surveillance and public health initiatives remain crucial in the ongoing fight against asbestos-related diseases.