Mesothelioma
Mesothelioma due to Asbestos Exposure
Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body’s internal organs, the mesothelium. It is usually caused by exposure to asbestos.
Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the heart, the pericardium (a sac that surrounds the heart) or tunica vaginalis.
Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. It has also been suggested that washing the clothes of a family member who worked with asbestos can put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases the risk of other asbestos-induced cancers. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).
The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.
Signs and symptoms
Symptoms or signs of mesothelioma may not appear until 20 to 50 years (or more) after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space (pleural effusion) 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 (hemoptysis)
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.
Cause
Working with asbestos is the major risk factor for mesothelioma. In the United States, asbestos is the major cause of malignant mesothelioma and has been considered “indisputably” associated with the development of mesothelioma. Indeed, the relationship between asbestos and mesothelioma is so strong that many consider mesothelioma a signal or sentinel tumor. A history of asbestos exposure exists in most cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite. Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.
Asbestos was known in antiquity, but it wasn’t mined and widely used commercially until the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not publicly known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the official position of the U.S. Occupational Safety and Health Administration (OSHA) and the U.S. EPA is that protections and “permissible exposure limits” required by U.S. regulations, while adequate to prevent most asbestos-related non-malignant disease, they are not adequate to prevent or protect against asbestos-related cancers such as mesothelioma. Likewise, the British Government’s Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE assumes that no such “safe” threshold exists. Others have noted as well that there is no evidence of a threshold level below which there is no risk of mesothelioma. There appears to be a linear, dose-response relationship, with increasing dose producing increasing disease. Nevertheless, mesothelioma may be related to brief, low level or indirect exposures to asbestos. The dose necessary for effect appears to be lower for asbestos-induced mesothelioma than for pulmonary asbestosis or lung cancer. Again, there is no known safe level of asbestos to asbestos as it relates to increased risk of mesothelioma.
The duration of exposure to asbestos causing mesothelioma can be short. For example, cases of mesothelioma have been documented with only 1-3 months of exposure. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
Latency, the time from first exposure to manifestation of disease, is prolonged in the case of mesothelioma. It is virtually never less than fifteen years and peaks at 30-40 years. In a review of occupationally related mesothelioma cases, the median latency was 32 years. Based upon the data from Peto et al, the risk of mesothelioma appears to increase to the third or fourth power from first exposure.
Conclusions
Human beings are susceptible to diseases that make our body weak but conditions such as cancer make us emotionally low as well, due to the fear factor and loss of hope involved, which is a result of lack of proper cure. The uncertainty of life hits home hardest when any type of cancer is diagnosed.
Mesothelioma is one of the most common primary tumors involving the pleura, which is the outer covering of the lungs and the cavity of the chest. It may sometimes occur in the peritoneum too, which is the abdominal cavity lining or even the pericardium surrounding the heart. This cancer is considered to be difficult for physicians to diagnose and treat.
There are different ways in which a person can get affected by this dreaded disease.
Mesothelioma due to asbestos exposure is the most common. Who would have thought that a simple exposure to a substance that is used in many products and in workplaces can spell disaster?
Asbestos exposure has been proved to lead to serious and fatal diseases, such as mesothelioma. Unfortunately, the symptoms are slow to show up and take a long time to develop and in some cases it may take more than twenty years. Research shows that people who smoke tobacco and have been exposed to asbestos are at a far greater risk for cancer than non-smokers.
There are several factors that determine how an individual is affected by this exposure, such as the concentration of the asbestos fibers, the duration of the exposure, the shape, size and the chemical elements of the fibers. Physicians believe that the thin and long fibers are the most dangerous because they can reach the alveolar region, the lower airways of the lung, and remain in the lung for a longer period of time and are more toxic than the other short or wide fibers. The wider particles cannot reach the lung and pleura and remain in the upper respiratory tract.
Occupational exposure to asbestos has been considered as a hazard for a long time. This risk of asbestos exposure is more apparent at workplaces, such as shipyards, mines, manufacturing plants, construction sites, railroads and several other places. This exposure usually occurs when the asbestos products are damaged.
Earlier, when asbestos mining used to take place, while no deaths were reported during the first ten years of exposure, there were reports of eighty-five deaths occurring in 20 years time. Even people with a minimal exposure of breathing air through ventilation systems have been diagnosed with mesothelioma.
Secondary or bystander exposure, meaning people who get exposed to asbestos through some other family member or someone else who is directly exposed to asbestos, also are at high risk of mesothelioma. Experts believe that this could be because of the asbestos dust that the workers bring home on themselves. To ensure the family members do not get affected, usually companies make it a rule that asbestos workers shower and change their clothes before going off work.
Environmental exposure to mesothelioma refers to people who are living in areas where there are asbestos mines or manufacturing plants. There was a case at Libby Montana, where vermiculite, which is a non asbestos mineral silicate was found to be highly contaminated with asbestos and children who played in the vermiculite heaps in the town were said to have developed mesothelioma and other related diseases. Non industrial exposure may occur because of soil that is contaminated with fibers or the use of erionite, which is a fibrous rock in buildings.
Workers, who perform renovation of buildings containing asbestos materials as well as people living in the surrounding areas where the renovation is taking place, are also exposed to asbestos dust and thus are at risk of contacting mesothelioma. Previously, before asbestos was banned, asbestos was used as part of building materials for both domestic and public premises.
The main and the only known cause of mesothelioma worldwide is exposure to asbestos. It is often related to some sort of occupational exposure, even if it is for a brief duration.
Researchers have found that asbestos manufacturers knew the hazards of asbestos exposure even as long as fifty to sixty years ago; however, they chose not to reveal this as it could affect their businesses and profits. It was in the 1960s that the first warnings came out to public notice, but were never stressed enough to make people understand the implications.
Even in the present day, there are many cases where workers are not completely aware of the health hazards, leaving them at a huge risk of falling prey to the dreaded mesothelioma and other such conditions.
It is unfortunate that thousands of individuals suffer and lose their lives for no mistake of theirs and part of it is because people have become so insensitive to fellow human beings’ suffering.