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Asbestos: What is it?
Asbestos is the name given to a group of minerals that occur naturally as masses of fibers, which can be separated into thin threads and woven. There are four main types of asbestos: Chrysotile, Amosite, Crocidolite and Anthophylite. Because these fibers are not affected by heat or chemicals and because they do not conduct electricity, asbestos is widely used in many industries. The fiber masses have a tendency to break easily into a dust of tiny particles that can float in the air, stick to clothes, and may be easily inhaled or swallowed.
How is Asbestos Used?
Asbestos has been mined and used commercially in North America since 1880, but its use increased greatly during World War II. Asbestos has been used in many industries during the past four decades. For example, the building and construction industry uses it for strengthening cement and plastics as well as for heat insulation, fireproofing and sound absorption. The shipbuilding industry has used asbestos to insulate boilers, steam pipes, hot water pipes, and nuclear reactors in ships. Because of its good friction and wear characteristics, asbestos is a component of the brake shoes and clutch pads of cars and trucks. It is estimated that patents have been issued for more than 5,000 different asbestos-containing products. The following list includes some of the products that now contain or have contained asbestos: pipe insulation, block insulation, refractory cements, insulation cement sheets, millboard plaster cement, pipe roofing products, floor tile, gaskets packing caulking, asbestos cloth, heat resistant clothing.
What are the health hazards of exposure to Asbestos?
Exposure to asbestos may increase the risk of these serious diseases:
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Asbestosis- a chronic lung ailment that can produce shortness of breath, permanent lung damage
and increased risk of dangerous lung infections.
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Mesothelioma (Lung Cancer) - a relatively rare cancer of the thin membranes lining the chest and
abdomen.
While all types of asbestos fibers may increase the risk of developing these diseases, some scientists believe that crocidolite and amosite are more likely to produce mesothelioma than is chrysotile. However, because most workers have been exposed to a variety of asbestos fiber types during their lifetime, it has not yet been possible to confirm this finding.
Who is at risk?
Since the early 1940s, millions of American workers have been exposed to asbestos dust, including many of the 4.5 million men and women who worked in shipyards during the peak shipbuilding years of World War II. Health hazards from asbestos dust have been recognized among workers exposed in ship building trades, asbestos mining, asbestos manufacturing, insulation work in the construction and building trades, automotive brake repair, and a variety of other trades. Demolition workers and drywall removers also may be heavily exposed to asbestos dust. As a result of Government regulations and improved work practices, current workers risks than those exposed in the past. Even workers who may not have worked directly with asbestos, but whose jobs were located near contaminated areas, have developed asbestosis, mesothelioma, or other cancers associated with asbestos exposure.
Workers may not begin to show signs of asbestos-related diseases for many years following first exposure. For example, the period of time between first exposure to asbestos and the appearance of lung cancer is generally 15 years or more; a lag of 30 to 35 years is not unusual. The lag period for development of mesothelioma and asbestosis is even greater, often as long as 40 to 45 years. There is also some evidence that family members of workers heavily exposed to asbestos face an increased risk of developing mesothelioma and perhaps other asbestos-related diseases, probably as a result of exposure to asbestos dust brought into the home on the shoes, clothing, skin and hair of workers.
How great is the risk?
Not all workers exposed to asbestos will develop diseases related to their exposure. In fact, many will not suffer any ill effects. Asbestos bonded in finished products is not a risk to health, as long as the product is not damaged or disturbed (for example, by sawing or drilling) in such a way to release fibers into the air. Since the fibers are nearly indestructible, a risk exists if they are set free. Once the asbestos particles work their way into the body tissues, they tend to stay there indefinitely.
How does smoking affect risk?
Many studies have shown that the combination of smoking and asbestos exposure is particularly hazardous.
While asbestos exposure itself can increase the risk of developing lung cancer, asbestos and cigarette smoking together may increase lung cancer risk over the already high risk due to smoking alone.
Cigarette smokers, on the average, are 10 times as likely to develop lung cancer as nonsmokers. Smokers who are also heavily exposed to asbestos have been shown to be up to 90 times more likely to develop lung cancer than non exposed individuals who do not smoke.
Who needs to be examined?
Individuals who have been exposed (or suspect they have been exposed) to asbestos dust on the job, or at the home via a family contact, should inform their physician of their work history and any symptoms. A thorough physical examination, including a chest x-ray and lung function tests, may be recommended. Interpretation of the chest x-ray may require the help of a specialist who is experienced in reading x-rays for asbestos-related diseases. Other tests also may be necessary. The symptoms of asbestos-related diseases may not become apparent for many decades after exposure. If any of the following symptoms develop, a physical examination should be scheduled without delay: Shortness of breath, A cough or change in cough pattern, Pain in the chest or abdomen, Difficulty in swallowing or prolonged hoarseness.
What are the treatments for asbestos-related diseases?
The key to successful treatment of asbestos-related diseases lies in early detection. The health problems caused by asbestosis are due mainly to lung infections, like pneumonia, that attack weakened lungs. Early medical attention and prompt, aggressive treatment offer the best chance of success in controlling such infections. As a protective measure, depending on the situation, doctors may give one of the vaccines against influenza or pneumoccoccal pneumonia.
Individuals exposed to asbestos should:
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Stop smoking.
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Get regular health checkups.
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Get prompt medical attention for any respiratory illness.
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Use all protective equipment, work practices and safety procedures designed for working around asbestos.
Malignant Mesothelioma - Lung Cancer
What is it? Malignant mesothelioma, a rare form of cancer, is a disease in which (malignant) cancer cells are found in the sac lining the chest (the pleura) or abdomen (the peritoneum). Malignant mesothelioma is the most serious of all asbestos-related diseases. Virtually all cases of malignant mesothelioma are attributable to asbestos exposure.
How is it found? An x-ray is often the first indication of mesothelioma. For confirmation of the disease a pathology from a biopsy or operation is required.
How is it treated? Like most cancers, malignant mesothelioma is best treated when it is diagnosed early. Mesothelioma progresses through stages. In the early stages, the cancer is found in the lining of the chest cavity near the lung and heart or in the diaphragm or the lung. In the advanced stages of mesothelioma, the cancer spreads beyond the lining of the chest to lymph nodes in the chest. Mesothelioma may continue to spread into the chest wall, center of the chest, heart, through the diaphragm, or abdominal lining, and in some cases into nearby lymph nodes. Eventually the mesothelioma may spread to distant organs or tissues.
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