Mesothelioma Frequently Asked Questions
- What is asbestos?
- Where is asbestos found?
- How does asbestos enter the environment and get inhaled?
- What happens when someone inhales asbestos fibers?
- What are the possible health risks of asbestos?
- Who is at risk for exposure?
- What should I do if I've been exposed?
- What is vermiculite?
- What is the mesothelium?
- What is the peritoneum?
- What is the pleura?
Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. It is a fibrous, silicate mineral known for its durability, heat-resistance, and chemical inertness. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and in a variety of building construction materials for insulation and as a fire-retardant.
These naturally occurring fibers have been mined and used for about the last 100 years with peak use in the 1970's. At that time adverse health effects were widely associated with the use of asbestos. Although asbestos use has drastically declined in the United States, it continues to be used in developing countries. There are three main types of asbestos.
- Chrysotile (white asbestos) is the most common form of asbestos in the United States and Canada and may be the least harmful. The fibers are fine, smooth, and white.
- Amosite (brown asbestos) is most often used in thermal insulation systems. The fibers are brittle and straight.
- Crocidolite (blue asbestos) consists of straight fibers and is used less often than the other two.
Products and buildings that include asbestos are known as Asbestos Containing Materials (ACM). Anthopylite, Tremolite, and Actinolite are three other forms of asbestos that can also be found in ACM.
The Environmental Protection Agency (EPA) and the Consumer Product Safety Commission (CPSC) have banned several asbestos products. Manufacturers have also voluntarily limited uses of asbestos. Today, asbestos is most commonly found in older homes, in pipe and furnace insulation materials, asbestos shingles, millboard, textured paints and other coating materials, and floor tiles. More information about asbestos can be found at http://www.epa.gov/iaq/asbestos.html and http://www.epa.gov/asbestos/.
In the United States, asbestos has been used in a variety of industries and products. Some examples of products that contain asbestos include:
- Building materials, like cement and plastics;
- Heat insulation and fire proofing; and
- Brake shoes and clutch pads in vehicles and airplanes.
There are several general categories into which ACM can be classified:
- Surfacing materials, such as the acoustical material on the ceilings of many homes, schools, and other buildings;
- Thermal System Insulation (TSI), such as the wrapping around boilers, pipes, and duct systems; and
- Other materials, such as floor tile, electrical panel insulation, and caulking.
How does asbestos enter the environment and get inhaled?
When people inhale air, it always contains small particles. These particles have to be filtered out because the lungs need to remain sterile. The nose and the bronchi (the airways leading down to the lungs) are the main air filters for the lungs.
Asbestos particles (called amphiboles) are long, extremely thin, microscopic glass-like fibers that are not filtered by the nose or the bronchi because they are so thin and light, which is how the fibers end up in people's lungs.
What happens when someone inhales asbestos fibers?
Asbestos fibers are harmful to humans if inhaled. When a person breathes in the small fibers, they remain in the lungs and cause scar tissue to form on the walls of the alveoli (the tiny air sacs where oxygen and carbon dioxide are exchanged). The amount of oxygen that is available to the body is reduced through asbestos exposure and worsened through repeated encounters with ACM.
What are the possible health risks of asbestos?
There are several asbestos-related diseases that can result from inhaling asbestos fibers, including:
- Asbestosis (pulmonary fibrosis);
- Mesothelioma;
- Lung cancer; and
- Other cancers that may result include esophageal, stomach, colon, and pancreatic.
Numerous studies attest to the link between cancer and asbestos. Many people who have been exposed do not develop asbestosis or cancer until fifteen or more years after their contact with ACM. Smokers have a significantly higher risk of contracting an asbestos related disease than non-smokers.
Most people with malignant mesothelioma and other asbestos diseases have worked on jobs where they breathed asbestos. Others have been exposed to asbestos in a household environment, often without knowing it. The Environmental Protection Agency asserts that there is no known level of safe exposure, but the following groups are thought have the highest exposure to ACM:
- Workers at a shipyard
- Janitors
- Plumbers
- Electricians
- Firefighters
- Telephone repair workers
- Mechanics
- Maintenance personnel
- Insulation installers
- Workers at an asbestos mine and mill
- Producers of asbestos products
- Workers in the heating and construction industries
- Trades people
- Friends and family of the above-listed workers and
- People who live or work near a facility that uses asbestos.
Even consumers have innocently exposed themselves and family members to asbestos through products like hair dryers, electric blankets, attic insulation, home siding and ceiling and floor tiles and other many products still being sold today.
An exposure of as little as one or two months can result in asbestos related diseases many years later, sometimes as long as 20 to 40 years later. People exposed in the 1940s, 50s, 60s, and 70s are now being diagnosed with mesothelioma because of the latency period of this deadly asbestos disease.
What should I do if I've been exposed?
If you believe you may have been exposed to asbestos, even for a very short period of time, it is important to see a physician immediately for a chest x-ray and lung function test.
Vermiculite is a naturally occurring mineral that may contain asbestos. Vermiculite has the unusual property of expanding into worm-like accordion shaped pieces when heated. The expanded vermiculite is a light-weight, fire-resistant, absorbent and odorless material. These properties allow vermiculite to be used to make numerous products, including attic insulation, packing material and garden products.
Asbestos contamination in vermiculite and vermiculite products has become a national concern to a variety of federal agencies including the Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OSHA) Agency for Toxic Substances and Disease Registry (ATSDR), and the Consumer Protection Safety Commission (CPSC), as well as to many private citizens throughout the country. Additional information about vermiculite can be found at http://www.epa.gov/asbestos/verm.html.
The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.
The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women.
The peritoneum is a thin membrane that covers the abdominal cavity and partially covers some of the abdominal organs.
The pleura is a thin membrane that covers the lungs (visceral pleura) and lines the chest cavity (parietal pleura).