Mesothelioma's Cause : Asbestos Exposure

Friday, October 30, 2009

At some point in our lives, nearly all of us have been exposed to asbestos in the air we breathe and the water we drink; from natural deposits in the earth, and from the deterioration of asbestos products around us. Most of us, however, do not become ill as a result of our exposure. More commonly, those who at some point are diagnosed with asbestos disease, have worked in jobs where more substantial exposure occurred over longer periods of time.

Nevertheless, cases of mesothelioma have been documented as the result of lesser exposure, affecting family members of workers who came into contact with asbestos and brought it home on their clothing, skin or hair, or affecting those who lived in close proximity to asbestos manufacturing facilities. Symptoms of asbestos disease usually are not be apparent until decades after exposure.

Asbestos was used commercially in North America as early as the late 1800s, but its use increased dramatically during the World War II era when shipyards produced massive numbers of ships for the war effort. Since that time, asbestos-containing products were used by the construction and building trades, the automotive industry and the manufacturing industry. All told, more than 5,000 products contained asbestos.

For more than 50 years, products containing asbestos remained unregulated, and the manufacturers of those products continued to prosper, knowing full well that many of the millions of workers who came into contact with their products would ultimately suffer as the result of their actions.

Finally, in the late 1970s, the Consumer Products Safety Commission banned the use of asbestos in wallboard patching compounds and artificial ash for gas fireplaces because the fiber could easily be released during use. In 1989, the Environmental Protection Agency banned all new use of asbestos, but uses established prior to that time were still allowed. Although awareness of the dangers of asbestos and public concern over the issue have led to a decline in domestic consumption over the years, a total ban on asbestos has not come to fruition. Asbestos is still imported, still used and still dangerous.

Signs and Symptoms

Symptoms of mesothelioma may not appear until 20 to 50 years after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space are often symptoms of pleural mesothelioma.

Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites(a buildup of fluid in the abdominal cavity). Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.

These symptoms may be caused by mesothelioma or by other, less serious conditions.

Mesothelioma that affects the pleura can cause these signs and symptoms:
• Chest wall pain
• Pleural effusion, or fluid surrounding the lung
• Shortness of breath
• Fatigue or anemia
• Wheezing, hoarseness, or cough
• Blood in the sputum(fluid) coughed up

In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax or collapse of the lung. The disease may metastasize or spread, to other parts of the body.

Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:
• Abdominal pain
• Ascites or an abnormal buildup of fluid in the abdomen
• A mass in the abdomen
• Problems with bowel function
• Weight loss

In severe cases of the disease, the following signs and symptoms may be present:
• Blood clots in the veins, which may cause thrombophlebitis
• Disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs
• Jaundice or yellowing of the eyes and skin
• Low blood sugar level
• Pleural effusion
• Pulmonary emboli, or blood clots in the arteries of the lungs
• Severe ascites

A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.

WHAT IS MESOTHELIOMA

Mesothelioma is a form of cancer that is almost always caused by previous exposure to asbestos. In this disease, malignant cells develop in the mesothelium, a protective lining that covers most of the body's internal organs. Its most common site is the outer lining of the lungs and chest cavity, but it may also occur in the peritoneum (the lining of the abdominal cavity) pleura or the pericardium (a sac that surrounds the heart).

Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or have been exposed to asbestos dust and fibre in other ways, such as by washing the clothes of a family member who worked with asbestos, or by home renovation using asbestos cement products. Unlike lung cancer, there is no association between mesothelioma and smoking.

3 MAIN TYPES OF MESOTHELIOMA

Epithelioid
An epithelioid cell is a cell whose morphology resembles that of epithelial cells, and classified as a primary body tissue. This is the most common type, and it tends to have a better outlook (prognosis) than the other types.

Sarcomatoid (fibrous)
About 1 or 2 out of 10 mesotheliomas are of this type.

Mixed (biphasic
This type has features of the 2 types above. About 3 or 4 out of 10 mesotheliomas are the mixed type.