Exposure to asbestos is considered the primary risk factor for developing malignant mesothelioma, an aggressive form of asbestos cancer. It is estimated that as many as 27 million people across the country were exposed to asbestos before its use largely ceased in the United States. In addition to happening in the workplace, exposure could have occurred through hundreds of household and industrial products, including pipe covering, roofing materials, floor tiling, and certain adhesives. The greater the period of time that a person was exposed, and the greater the amount of asbestos s/he was exposed to, the greater the risk that s/he will develop mesothelioma. However, those who were exposed for short periods, or to small amounts, may also be at risk.
Understanding this risk involves understanding some basics about asbestos and how exposure occurs. Asbestos shares many qualities with cloth, but is much more durable. There are two forms of asbestos fibers: amphibole, which are described by the American Cancer Society as “thin, rod-like fibers,” and serpentine, which are described as “curly and pliable”. When particles are released into the air, they can be inhaled and then absorbed by the mesothelium (a membrane that lines the pleura, or chest wall, the peritoneum, or abdominal wall, and the pericardium, or sac surrounding the heart).
As a result, cells in the mesothelium can become cancerous over a period of 15-50 years after the initial exposure. Those who directly inhale asbestos fibers can also “carry” the risk with them into other environments. There are documented cases, for instance, of the family members of a worker being exposed to asbestos through fibers in clothing. This is called secondary, or limited, exposure.
Industries and jobs that involve exposure to asbestos include: aluminum plants; chemical plants; oil refineries; power plants; shipyards; steel mills; weavers; teachers; building inspectors; crane operators; and service people in the US Navy. Because asbestos was also used as a building material for many years, those who lived, worked or went to school in buildings with asbestos content may have also been exposed to it.
Asbestos was used commonly because of characteristics such as its strength and its ability to withstand heat. The risks of asbestos exposure were first discovered in the 1920’s, but its use continued for many years afterwards.
In certain cases, employers or industry groups systematically withheld important information about the risks of asbestos from workers and failed to provide adequate information about safety measures, or safety equipment.
In 1947, for example, an industry group called the Asbestos Textile Institute (ATI) commissioned a study on the risks of textile factories. This study concluded that workers should receive medical exams and advised the industry to re-examine its threshold limit for asbestos exposure. However, the results of this report were neither acted upon nor made public because the ATI believed it would irreparably damage the industry to do so. As a result several generations of workers were exposed to asbestos and, compared to other industries, disproportionate numbers of these individuals later developed mesothelioma. In recent years, many individuals and groups of workers whose health was impacted by asbestos exposure have won lawsuits against employers who knowingly withheld information about risk.
The use of asbestos peaked between 1950 and 1975. By 1989, the use of asbestos in the United States had largely ceased due to a ban issued by the Environmental Protection Agency. Two years later, the asbestos industry reversed this ban after filing a lawsuit and asbestos use is still legal in certain products or industries. These products, or processes, must be labeled as containing asbestos.
As well, many buildings still exist that were constructed using asbestos. For example, experts estimate that between 10 – 15% of schools across the country are insulated with material made with asbestos. When asbestos is detected in an older building, a process called abatement can be used to remove it and thus reduce the risk of exposure to workers or inhabitants. Abatement should be completed by professional abatement contractors who have both the expertise and the equipment to complete the removal safely. While asbestos use has largely halted in the United States, exposure to it can still occur.
One tragic example of this is the events surrounding the World Trade Center on September 11, 2001. Workers who participated in rescue and recovery efforts, as well as cleanup of the Ground Zero site, were exposed to asbestos that had been used in the North Tower. When the building collapsed, this asbestos was released into the air and then inhaled by those working at the site, and those living, working or going to school nearby.
A government agency called the Occupational Safety and Health Administration (OSHA), which is charged with creating and enforcing regulations about workplace and worker safety, monitors industries and specific companies for violations related to asbestos exposure. Health experts point to the reduced use of asbestos and increased regulation as primary reasons that the rate of mesothelioma has stopped rising. In addition to its continued use in the United States, asbestos is also still legal in certain foreign countries. International advocacy organizations continue to work with governments across the globe to enforce bans on asbestos use.
Asbestos was also used in the production of many commonly-used products in both the construction industry and the home. These include: roofing materials; siding; bricks; insulation, including sprayed insulation; vinyl flooring; drywall materials; cement panels; piping; fireproofing substances; talc-based products such as baby powder; wire insulation; emergency generators; fertilizers containing vermiculite; and certain textiles. Asbestos was also used in the production of many small appliances, such as toasters, coffee pots and hair dryers. Although rarer, people can also be exposed to asbestos in the natural environment because asbestos is a mineral.
Advocacy groups recommend that those who were exposed to asbestos through their workplace, school or home, or through products containing asbestos, consult with physicians to asses their respiratory health on a regular basis. It is also recommended that people evaluate the buildings and environments that they spend time in for the presence of asbestos.