Important Information about Asbestos and Mesothelioma

Mesothelioma is a rare aggressive cancerous disease of the mesothelium, which is a type of protective tissue that surrounds organs found in the thoracic and abdominal cavity such as the lungs, heart, liver, and abdominal organs. Most of the time, cancer does not occur with a single cause; rather it is a group of diseases with multiple causes, symptoms, treatments, and prognosis. But in the unique case of mesothelioma, there is a specific cause for this cancer which is asbestos.

Risk Factors

Several agents or factors are implicated in the development of mesothelioma. However, generally, asbestos is still the leading cause of mesothelioma.

Virus
In very rare situations, a Simian vacuolating virus (SV40) may act as a carcinogen and potentiate asbestos in causing malignant mesothelioma. The SV40 is a highly controversial virus due to the contamination of polio vaccines between the year 1955 and 1963. Millions of people in the United States were said to be exposed to the virus.
However, there is no clear evidence yet whether SV40 is responsible for certain mesotheliomas.

Erionite (Zeolite)

Exposure to erionate, a type of zeolite mineral which has similar properties with asbestos, is suggested to be one of the causes of mesothelioma in some villages in Turkey.

Radiation

Therapeutic radiation using thorium oxide (thorotrast) has been reported to increase the risk of developing pleural and peritoneal mesothelioma in certain people.

Smoking

Smoking alone is not considered to affect the development of mesothelioma, however, when smoking is combined with asbestos exposure, the risk of having mesothelioma significantly increases.

Asbestos

For several decades, asbestos remains the primary cause of the development of mesothelioma and a number of lung diseases. Inhalation of the particles is the most common route of entry, which is why most cases of mesothelioma occur in people working in the asbestos industry.

A Closer Look on Asbestos

Asbestos is the given name of a certain family of minerals that occur in fibrous form. These fibers can be processed into a variety of materials that are uniquely resistant to fire, heat, and corrosion. Asbestos can be spun and woven into textiles, matted into insulating materials, or used with other substances to make numerous products, including brake linings, clutch pads, and roofing and flooring materials. Because of these, asbestos is almost irreplaceable as no other substance provides its desirable properties.

Nevertheless, manufacturers are developing replacement materials because of the issues surrounding the production of asbestos products. Inhalation of asbestos’ very minute fibers over a period as little as one to two months has been linked to cancers of the lung, lung-cavity lining or mesothelioma, asbestosis, and severe lung impairment.

Types of Asbestos

There are two general varieties of asbestos: serpentine and amphibole.

Serpentine

Chrysotile, obtained from serpentine rocks, is the most abundant and widely used form of asbestos accounting for 90% of asbestos used for production of new materials.

Amphibole

Amphiboles are long, thin fibers that are more potent in causing lung cancer and associated diseases. Amphiboles include amosite (brown asbestos), crocidolite (blue asbestos), tremolite, actinolite, and anthophyllite. Among these, crocidolite is the more potent carcinogen which is due to its rod-like appearance that enables the fiber to easily penetrate the lungs and into the pleura. They may cause irritation and long-term inflammation of the mesothelium altering cellular structures leading to cancer. Asbestos can also cause the production of free radicals that damage cells that further potentiate cancer growth. It has been suggested that some of the fibers may be coughed up and swallowed into the gastrointestinal tract. In this way, asbestos can cause peritoneal (abdominal) mesothelioma.

People who are working with asbestos have the highest risk of contracting mesothelioma. But family members of these workers may also incur the disease due to particles that may be carried along with the worker’s clothing and hair. Aside from that, those who are residing in a room with products built from asbestos are likely to inhale the particles without knowing it. Houses and structure built in the late 1800s to mid 1900s are more prone to use such materials because asbestos has been widely used commercially during this period. The latency period of mesothelioma can last between 20 to 50 years following exposure to asbestos.

Diagnosis

Mesothelioma must be diagnosed using the medical history of a person and adiologic studies such as X-rays, CT scans, MRI, and PET scans. But because mesothelioma may mimic several lung conditions, there may be a need for chest tube thoracostomy, pericardiocentesis, or paracentesis depending on the location of the tumour. A biopsy will confirm the diagnosis of mesothelioma. The disease will be staged according to the TNM system: tumor (T), lymph node involvement (N), and metastasis (M).
Unfortunately, most cases of mesothelioma are diagnosed when it is already at its late stage. Treatment options vary depending on the staging and extent of metastasis. Surgery in adjunct to radiation and chemotherapy are the best options available. In advanced stages, treatment would be difficult; hence, palliative (supportive) care is rendered to treat the symptoms. However the disease itself is still there.

Despite the many dangers of asbestos usage, many people are still exposed to asbestos especially in countries like India, China, and Russia. The Environmental protection Agency (EPA) has estimated that 3,000 to 12,000 cases of cancer, usually fatal, are caused annually in the United States by asbestos exposure. But controversies continue to surround the issue of asbestos as a health hazard. Thousands of asbestos-related diseases and mortalities have been documented and yet, some countries have not placed any ban on asbestos products.