Health Hazards Caused by Exposure to Asbestos

What is asbestos?

Asbestos is the name given to a group of minerals that occur naturally in the environment as bundles of fibers that can be separated into thin, durable threads. These fibers are resistant to heat, fire, and chemicals and do not conduct electricity. For these reasons, asbestos has been used widely in many industries.

Chemically, asbestos minerals are silicate compounds, meaning they contain atoms of silicon and oxygen in their molecular structure.

Asbestos minerals are divided into two major groups: Serpentine asbestos and amphibole asbestos. Serpentine asbestos includes the mineral chrysotile, which has long, curly fibers that can be woven. Chrysotile asbestos is the form that has been used most widely in commercial applications. Amphibole asbestos includes the minerals actinolite, tremolite, anthophyllite, crocidolite, and amosite. Amphibole asbestos has straight, needle-like fibers that are more brittle than those of serpentine asbestos and are more limited in their ability to be fabricated.

What is asbestos used?

Asbestos has been mined and used commercially in North America since the late 1800s. Its use increased greatly during World War II. Since then, asbestos has been used in many industries. For example, the building and construction industries have used it for strengthening cement and plastics as well as for insulation, roofing, fireproofing, and sound absorption. The shipbuilding industry has used asbestos to insulate boilers, steam pipes, and hot water pipes. The automotive industry uses asbestos in vehicle brake shoes and clutch pads. Asbestos has also been used in ceiling and floor tiles; paints, coatings, and adhesives; and plastics. In addition, asbestos has been found in vermiculite-containing garden products and some talc-containing crayons.

Health hazards of exposure to asbestos

People may be exposed to asbestos in their workplace, their communities, or their homes. If products containing asbestos are disturbed, tiny asbestos fibers are released into the air. When asbestos fibers are breathed in, they may get trapped in the lungs and remain there for a long time. Over time, these fibers can accumulate and cause scarring and inflammation, which can affect breathing and lead to serious health problems.

Asbestos has been classified as a known human by the U.S. Department of Health and Human Services, the EPA, and the International Agency for Research on Cancer. Carcinogen is a substance that causes cancer.

Who is at risk for an asbestos-related disease?

Everyone is exposed to asbestos at some time during their life. Low levels of asbestos are present in the air, water, and soil. However, most people do not become ill from their exposure. People who become ill from asbestos are usually those who are exposed to it on a regular basis, most often in a job where they work directly with the material or through substantial environmental contact.

Since the early 1940s, millions of American workers have been exposed to asbestos. Health hazards from asbestos fibers have been recognized in workers exposed in the shipbuilding trades, asbestos mining and milling, manufacturing of asbestos textiles and other asbestos products, insulation work in the construction and building trades, and a variety of other trades. Demolition workers, drywall removers, asbestos removal workers, firefighters, and automobile workers also may be exposed to asbestos fibers.

Individuals involved in the rescue, recovery, and cleanup at the site of the September 11, 2001, attacks on the World Trade Center (WTC) in New York City are another group at risk of developing an asbestos-related disease. Because asbestos was used in the construction of the North Tower of the WTC, when the building was attacked, hundreds of tons of asbestos were released into the atmosphere. Those at greatest risk include firefighters, police officers, paramedics, construction workers, and volunteers who worked in the rubble at Ground Zero. Others at risk include residents in close proximity to the WTC towers and those who attended schools nearby. These individuals will need to be followed to determine the long-term health consequences of their exposure.

How does smoking affect risk?

Many studies have shown that the combination of smoking and asbestos exposure is particularly hazardous. Smokers who are also exposed to asbestos have a risk of developing lung cancer that is greater than the individual risks from asbestos and smoking added together.

Symptoms of asbestos-related diseases

The symptoms of asbestos-related diseases may not become apparent for many decades after the exposure. It is particularly important to check with a doctor if any of the following symptoms develop.

• Shortness of breath, wheezing, or hoarseness.
• A persistent cough that gets worse over time.
• Blood in the sputum (fluid) coughed up from the lungs.
• Pain or tightening in the chest.
• Difficulty swallowing.
• Swelling of the neck or face.
• Loss of appetite.
• Weight loss.
• Fatigue or anemia.

Medical Examination

A thorough physical examination, including a chest x-ray and lung function tests, may be recommended. The chest x-ray is currently the most common tool used to detect asbestos-related diseases. However, it is important to note that chest x-rays cannot detect asbestos fibers in the lungs, but they can help identify any early signs of lung disease resulting from asbestos exposure.

Studies have shown that computed tomography (CT) (a series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine) may be more effective than conventional chest x-rays at detecting asbestos-related lung abnormalities in individuals who have been exposed to asbestos.

A lung biopsy, which detects microscopic asbestos fibers in pieces of lung tissue removed by surgery, is the most reliable test to confirm the presence of asbestos-related abnormalities. A bronchoscopy is a less invasive test than a biopsy and detects asbestos fibers in material that is rinsed out of the lungs.

Programs are available to help individuals with asbestos-related diseases?

Some people with asbestos-related illness may be eligible for Medicare coverage. Information about benefits is available from Medicare’s Regional Offices, located in 10 major cities across the United States and serving specific geographic areas. The Regional Offices serve as the agency’s initial point of contact for beneficiaries, health care providers, state and local governments, and the general public. Contact information for each Regional Office can be found at http://www.cms.hhs.gov/RegionalOffices on the Internet. General information about Medicare is available by calling toll-free 1–800–633–4227 (1–800–MEDICARE) or visiting http://www.medicare.gov on the Internet.

Source: www.cancer.gov