Asbestos fibers
Key facts
- About 125 million people in the world are exposed to asbestos at their workplace.
- Due to occupational exposure each year over 107 000 people die from asbestos related lung cancer, asbestosis and mesothelioma, according to WHO estimates.
- One in every three deaths from occupational cancer is estimated to be caused by asbestos.
What is asbestos?
Asbestos is a set of six naturally appearing silicate minerals used commercially for their desirable physical properties
Their names are
- actinolite
- amosite
- chrysotile
- anthophyllite
- crocidolite
- tremolite
The principal forms of asbestos are white asbestos (chrysotile) and blue asbestos (crocidolite).
Crocidolite and amosite are the most dangerous of the asbestos minerals set because of their long persistence in the lungs of exposed people. Chrysotile is often contaminated with tremolite asbestos, thus creating an additional hazard. Chrysotile asbestos, can produced tumors in animals, like all other forms of asbestos minerals.
Asbestos crystals structure, make him different from most other crystalline minerals. Asbestos crystals become flexible, long, silky fibres, so it can be made into a wide variety of forms. Because it is resistant of high temperatures, his extraordinary tensile strength, and relative resistance to chemical attack, asbestos is used commercially for insulation in buildings and as an ingredient in a number of products, such as fire blankets, medical packing, plastic fillers, roofing shingles, and water supply lines, as well as clutches and brake linings, gaskets and pads in automotive industry.
In nature asbestos can be found in the air outdoors, indoors and in some drinkable water, including water from natural sources. Actual indoor and outdoor concentrations in the air range from below one hundred to several thousand fibres per m3.
Why is asbestos a serious problem - Asbestos and Health?
Raw asbestos crystals will split into individual fibers which are large enough to be seen, but they can split even further into microscopic fibers. These small fibers are flying in the air, and can even pass through some respiratory dust filters.
Why is asbestos a serious problem - Asbestos and Health?
Raw asbestos crystals will split into individual fibers which are large enough to be seen, but they can split even further into microscopic fibers. These small fibers are flying in the air, and can even pass through some respiratory dust filters.
When asbestos fibres are inhaled , they may cause scars in the lung tissue, cancer of the bronchial tree (lung cancer) and sometimes cancer in the pleura and peritoneum. If asbestos fibers are inhaled in a high concentration over a long time period of time it is more likely to cause some serious health problems. This is most common among asbestos miners, because these workers have the longest exposure to it.
To humans, all forms of asbestos are carcinogenic, and may cause mesothelioma, lung cancer, larynx and ovary cancer. Asbestos exposure is also responsible for other diseases, such as pleural plaques, asbestosis, thickening and effusions.
Patients who become ill from inhaling asbestos fibers are often those who are exposed on a day-to-day basis in a job where they worked directly with the asbestos materials. As a person's exposure to fibers increases, then that person's risk of the disease also increases, because of being exposed to higher concentrations of fibers and/or by being exposed for a longer time. Mesothelioma cancer and other asbestos related diseases are very unlikely to result from a short period of exposure to lower levels or from a single, high-level exposure.
Mesotheliomas have been observed on people who were occupationally exposed to white asbestos (chrysotile), population who lived close to asbestos mines and factories, and family members of the occupationally exposed. According to the NCI, "A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases. Asbestosis has been reported primarily in asbestos workers, and appears to require exposure to a high concentration over a long time period for the development of the clinical disease. There is also a long latency period of over 12 years. Some studies have shown an increased risk of lung cancer among smokers who are exposed to asbestos compared to nonsmokers.
Health Canada states that the asbestos content of a product does not indicate its health risk. Asbestos is hazardous to health only when asbestos fibres are in the air that people breathe.
The evidence that ingested asbestos causes gastrointestinal or other cancers is insufficiently proven. The carcinogenic properties of asbestos are most probably due to its fibre geometry and remarkable integrity; other fibres with the same characteristics may also be carcinogenic.
Current environmental concentrations of asbestos are not considered a hazard with respect to asbestosis. A risk of mesothelioma and lung cancer from the current concentrations can't be excluded.
Studies also shown that members of the general (non-occupationally exposed) population have tens of thousands to hundreds of thousands of asbestos fibers in each gram of dry lung tissue, which translates in millions of fibers and tens of thousands of asbestos bodies in every person's lungs. Health risks associated with exposure to NOA (naturally occurring asbestos) are not yet fully understood, and current US federal regulations do not address exposure from NOA.
Has the use of asbestos containing products changed during the years?
After it became evident that regular exposure to asbestos products on the job involved health risks, the public became more concerned about exposure to asbestos in offices and schools, and, eventually, about all asbestos products. This concern has led to a dramatic decline in asbestos products use since the early 1980s. The use of asbestos insulation products in heating systems and buildings has practically disappeared. Using asbestos products for roofing, appliances and flooring, also continues to decrease.
Today Hazardous Products Act regulates the sale of asbestos containing products. Asbestos is now better closed and sealed to reduce the escape of fibres. Asbestos is still valuable in many applications because it has been difficult to find comparable substitute materials. For example, it is an important component of clutch facings and brake lining.
If you believe that you or a loved one have been exposed to asbestos fibers, or if you or a loved one have been diagnosed with mesothelioma cancer, you can search for mesothelioma attorney in our directory.
See also:
- How asbestos fibres damage lung tissue and lead to mesothelioma cancer
- Asbestos and Its Diseases (e-book)
