MESOTHELIOMA’S CAUSE – ASBESTOS EXPOSURE
At some point in our lives, nearly all of us have been exposed to asbestos in the air we breathe and the water we drink; from natural deposits in the earth, and from the deterioration of asbestos products around us. Most of us, however, do not become ill as a result of our exposure. More commonly, those who at some point are diagnosed with asbestos disease, have worked in jobs where more substantial exposure occurred over longer periods of time. Nevertheless, cases of mesothelioma have been documented as the result of lesser exposure, affecting family members of workers who came into contact with asbestos and brought it home on their clothing, skin or hair, or affecting those who lived in close proximity to asbestos manufacturing facilities. Symptoms of asbestos disease usually are not be apparent until decades after exposure.
Asbestos was used commercially in North America as early as the late 1800s, but its use increased dramatically during the World War II era when shipyards produced massive numbers of ships for the war effort. Since that time, asbestos-containing products were used by the construction and building trades, the automotive industry and the manufacturing industry. All told, more than 5,000 products contained asbestos.
For more than 50 years, products containing asbestos remained unregulated, and the manufacturers of those products continued to prosper, knowing full well that many of the millions of workers who came into contact with their products would ultimately suffer as the result of their actions. Finally, in the late 1970s, the Consumer Products Safety Commission banned the use of asbestos in wallboard patching compounds and artificial ash for gas fireplaces because the fiber could easily be released during use. In 1989, the Environmental Protection Agency banned all new use of asbestos, but uses established prior to that time were still allowed. Although awareness of the dangers of asbestos and public concern over the issue have led to a decline in domestic consumption over the years, a total ban on asbestos has not come to fruition. Asbestos is still imported, still used and still dangerous.
Although it is suggested that the number of mesothelioma cases in the U.S. has reached its peak and has begun to drop, a forecast released by the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (SEER), in April, 2003, projected the total number of American male mesothelioma cases from 2003-2054 to be approximately 71,000. This number, however, does not take into consideration events such as the World Trade Center disaster on September 11, 2001, when millions of New Yorkers were potentially exposed to air filled with carcinogenic asbestos particles. The incidence of mesothelioma cases by state and county are shown in these tables. When the latency period for asbestos disease is factored in, cases of mesothelioma will continue to be diagnosed for years to come. See our page on mesothelioma risk factors.
Does exposure to asbestos always cause mesothelioma? No, less than 10% of people with a history of heavy asbestos exposure develop mesothelioma. But 80% of those with pleural mesothelioma have a demonstrated history of asbestos exposure. There is no doubt that exposure to asbestos fibers increases the risk of mesothelioma. This is why you should mention any history of asbestos exposure to a doctor attempting a diagnosis.
Questions Regarding the Risk Level of Asbestos Exposure
Research data has shown that there is a definite correlation between exposure to asbestos particles and asbestos-related diseases, especially for those that are exposed to the fibers in their workplace. Even though data shows a connection between these factors, there is ongoing debate as to just “how much of a risk is present” in environments where asbestos fibers can be found.
Questions have been raised because some of the factors relating to asbestos exposure can vary considerably sometimes making it difficult to define absolute asbestos-related exposure relationships. Some of these variables include asbestos fiber sizes and types, the type of asbestos-related disease, and the duration and level of exposure to the fibers.
Even with the uncertainty, progress has been made in regards to these variables and their effects on human health over the last 25 years. This information may present an issue for regulating authorities and agencies because it may require a deviation from their current opinions on asbestos exposure and its effects on health.
Differing Characteristics of Asbestos Fibers as They Relate to Health Conditions
People that have inhaled asbestos fibers have been shown to develop health conditions such as asbestosis, mesothelioma, and lung cancer. There is confusion as to which asbestos types pose a greater risk of asbestos-related disease and to what degree. Additionally, there are questions regarding which exposure conditions present this risk.
One problem in regards to establishing clear-cut asbestos-related factors may be the use of the term “asbestos”, as a catch-all or general term used to represent various asbestos fibers that have different toxic characteristics and tendencies that cause related diseases.
More than 150 studies of asbestos particles has been used to determine the relationship between incidences of asbestos disease and suspected factors; however, this research has had little value in determining level of risk due to limited data on levels of human exposure, fiber types, and other possible contributing factors (i.e. smoking or other lifestyle practices). Other obstacles that contribute to the limitations of this research include the use of many different fiber types or the lack of defining fiber types used in studies.
Sources for the information on this page:
Agency for Toxic Substances and Disease Registry – Tremolite Asbestos Health Consultation
National Cancer Institute – Asbestos Exposure and Cancer Risk
Centers for Disease Control – Work-Related Lung Disease (WoRLD) Surveillance System
American Journal of Pathology – Pulmonary reaction to long and short asbestos fibers is independent of fibroblast growth factor production by alveolar macrophages
American Council on Science and Health