Doran & Murphy, PLLC

Asbestosis, Lung Cancer, Mesothelioma
Asbestos is a fibrous mineral that has been widely used throughout the United States as an insulation material. There are many different types of asbestos fibers but the most common include chrysotile, amosite and crocidolite. In addition to being very strong and durable, asbestos fibers are heat resistant. These properties made asbestos very popular in the construction and manufacturing industries for much of the last century.

Asbestos can become friable, or crumbly, when it is disturbed in any way (ie – pipe insulation repair) or due to simple “wear and tear” and aging. As a result, microscopic fibers invisible to the human eye can break apart and become airborne. Once airborne, the fibers remain in the air for extended periods of time and can be breathed in by individuals in the area. The small size and shape of these fibers cause them to become trapped in the lungs.

Photos taken from: Pulmonary Pathology,” Chapter 28 on Asbestos, ed. Samuel P. Hammer and David H. Dail (1994, 2nd ed.)

Exposure to asbestos has occurred in many occupational and non-occupational settings, yet it is important to note that the Environmental Protection Agency (EPA) concludes that there is no safe level of exposure to asbestos fibers. In 1978, the National Institutes of Health estimated that 8 – 11 million persons were occupationally exposed to asbestos since the early 1940′s in the U.S. Not only people who worked under conditions where they were exposed to asbestos are at risk. Family members may also be at risk since asbestos fibers easily become airborne and, therefore, can come into the home on the clothing of the worker.

It is well recognized that asbestos can cause asbestosis, asbestos related pleural disease, lung cancer(as well as other forms of cancer), and mesothelioma. This recognition led the federal government to impose guidelines under OSHA restricting asbestos use and exposure beginning in 1971. The United States Congress has also found that there is not “any minimum level of exposure to asbestos fibers which is considered to be safe to individuals exposed to the fibers,” Title 20 U.S.C. Chapter 49, Section 3601.

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Are you at risk?
Some of the work environments, or trades, in which people came, or still may come in contact with asbestos are:

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Asbestos Related Health Disorders

Mesothelioma: is a rare form of cancer affecting the lining of the lungs or abdomen (thoracic and abdominal cavities and surrounding internal organs including the gastro-intestinal tract) that is only caused by asbestos. Mesothelioma is the most insidious of the asbestos-related diseases in that it can affect people who have experienced low or intermittent levels of asbestos exposure. Symptoms of mesothelioma are: shortness of breath, pain in the lower back or side of the chest, coughing, and weight loss The prognosis for those unfortunate enough to contract this disease is generally poor, with less than 10% surviving beyond 2 years after initial diagnosis. Treatment options include surgery, chemotherapy, and radiation therapy. There are other experimental treatment options which should be discussed with your care provider, including gene therapy and multimodality treatment. The latency period for mesothelioma is at least 15 years with most reports supporting a latency period of 30-40 years.

Lung Cancer: Asbestos has been linked to many forms of cancer but by far the most common is lung cancer. Asbestos associated lung cancers can be of different types (squamous cell, adenocarcinoma, small cell and large cell) and can occur in all areas of the lung (upper and lower lobes). Ample medical evidence exists linking lung cancer to asbestos exposure, even in the absence of pulmonary fibrosis on chest x-ray. A common latency period of 20 years or more exists for lung cancer caused by asbestos exposure. Treatment options include surgery, chemotherapy and radiation.

Asbestos has also been linked to laryngeal (throat) cancer, esophageal, cancer of the colon, and other types of cancer. It is important to note that asbestos may be a causative agent in many types of cancer even in people who smoke.

Asbestosis: Asbestosis is a diffuse fibrous hardening and scarring of the lungs caused only by the inhalation of asbestos fibers. This scarring is permanent condition for which there is no cure able to cause lung impairment and heart disease. Unfortunately, due to the fact that the inhaled fibers are trapped in the lung, the condition can get worse even after exposure ceases. Symptoms of asbestosis include shortness of breath, coughing and chest discomfort including a dry crackling sound while inhaling. In advanced stages, asbestosis may cause cardiac failure. Generally, it takes at least fifteen to twenty years or more from the onset of exposure for the disease to manifest itself. This characteristic of asbestosis is known as the latency period. The scarring of asbestosis is usually first detected by chest x-ray and may also result in diminished lung capacity (pulmonary function).

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Asbestos Related Pleural Disease: Exposure to asbestos can also cause changes to the lining of the chest and lungs known as the pleura. There are two primary types of non-malignant (non-cancerous) pleural disease:

Pleural Thickening: Asbestos fibers which penetrate the lung can also lodge the pleura and cause a generalized inflammatory reaction. This reaction causes the chest wall lining to permanently thicken. Pleural fluids can progress to diminish lung function, restricting breathing capacity and, according to some studies, can develop into cancer (mesothelioma). Pleural thickening can be detected by chest x-ray.

Asbestos fibers tapped in the pleura can also cause more localized reactions leading to areas of hard scar formation. Over time calcium may be deposited in the scars. The presence of calcified pleural plaques on both sides of the chest is considered to be definite evidence of asbestos exposure and is generally easily detected by a ‘B-Reader’ from chest x-ray films.

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The Relationship Between Cigarette Smoking and Asbestos Exposure:
A frequently asked question concerns the relationship between cigarette smoking and asbestos exposure. Smoking has well known adverse health consequences including being a cause of carcinoma of the lung. However, asbestos is also known to cause lung cancer even in the absence of smoking. In cases where individuals suffered exposure to asbestos and also smoked cigarettes, careful medical evaluation can often determine whether asbestos, cigarettes, or the combination produced the disease. Smoking and asbestos have a “synergistic effect”, meaning that the risks associated with each are not merely additive in causing cancer, but rather are multiplicative. Some studies have suggested that persons who are exposed to asbestos and who smoked are at least 50 times more likely to develop cancer. Persons who have been exposed to asbestos can reduce their risk of developing lung cancer by quitting smoking. It is never too late to quit smoking.

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Asbestos Manufacturer Knowledge:
Documents obtained through discovery in asbestos cases clearly establish that the manufacturers of asbestos products were well aware of the hazards of asbestos at least as early as the 1930s. The documents also demonstrate that the manufacturers were very intent on keeping the dangers of asbestos from the public so as not to hurt their product sales and products.

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What To Do If You Suspect or Were Exposed to Asbestos:
Persons who have had significant exposure to asbestos should undergo regular and periodic check-ups to test for the presence of asbestos related disease. Such check-ups should include annual chest x-rays (PA and lateral). The National Institute of Occupational Safety and Health (NIOSH) administers a specialized program which trains and certifies a limited number of physicians to interpret chest x-rays for signs consistent with asbestos related diseases. The certificate process is rigorous and it is important that x-rays of asbestos exposed individuals be interpreted by a NIOSH certified B reader, who is the only person qualified to interpret these x-ray films. A certified radiologist who is a non-certified B-reader will often see no asbestos related disease when viewing chest x-rays; this person is not qualified to rate these films and sub-sequentially their interpretation does not rule out the presence of these diseases. if you suspect you’ve been exposed to asbestos, get tested by a doctor.

Additional Asbestos Information at these Websites:

Agency for Toxic Substances and Disease Registry:
Asbestos, Toxicological Profile

American Cancer Society

American Lung Association Info

Chrysotile.com The Asbestos Institute National Cancer Institute

Occupational Safety & Health – Asbestos

OSHA Safety and Health Topics: Asbestos

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