What is Asbestos
There are six different naturally occurring minerals that are referred to as asbestos. The six asbestos minerals are chrysotile, crocidolite, amosite, anthophyllite, tremolite, and actinolite. All the types of asbestos are comprised of tiny fibers that are strong, heat resistant and chemical resistant, making asbestos useful as an ingredient in many manufactured products including, roof shingles, tiles, cement products, automotive products, and textiles. The downside to asbestos is that it is dangerous to human health. Because of the dangers to human health that asbestos poses, the use of asbestos has been banned in many, but not all products. Asbestos containing insulation, ceiling tiles, floor tiles, and roof shingles are no longer used in home and school buildings in most areas. However, asbestos containing products are still found in some older buildings.
Asbestos: Ecological Impacts
Asbestos fibers are so small that they cannot be seen by the naked eye or even by normal household microscopes. The tiny asbestos fibers are released into the environment during mining for the asbestos materials (when the asbestos is harvested from rock formations) and when manufactured materials containing asbestos are disturbed.
When asbestos is released into the environment it contaminates the air (where it can be inhaled), water (where it can be ingested) and soil. Asbestos can travel for long distances in the air before it settles into water or atop of soil, thus contaminating areas far away from its source. The small asbestos fibers remain intact in air, water and soil. It does not break down or biodegrade. The fibers do not absorb into the soil and instead sit on top of the soil, where it can easily be disturbed and redistributed into the air.
If products made from asbestos are not properly contained, asbestos fibers are released into the environment where they can affect human health.
Zimbabwean Asbestos Mine
Human Exposure to Asbestos
Because asbestos is naturally found in the environment and mined for and used in the manufacture of products, it is not possible to completely avoid asbestos exposure. The Department of Health and Human Services Agency for Toxic Substances and Disease Registry (ATSDR) states that every person has been "exposed to low levels of asbestos in the air we breathe" and estimates that the exposure is "highest in cities and industrial areas," with levels ranging from "0,00001 to 0.0001 fibers per milliliter of air."The Environmental Protection Agency estimates however, that a lifetime of breathing air contaminated with low-levels of asbestos fibers (0.000004 fibers/mL(2)) increases the chances of a person developing asbestos related cancer by "one-in-a-million."
Low-level asbestos exposure is believed to pose minimal health consequences, but high-level exposure is linked to lung disease. The higher the amounts of asbestos you are exposed to, the higher the risks of lung disease. Smokers have an increased risk of developing lung disease when exposed to asbestos. The three types of lung disease linked to asbestos exposure are asbestosis (a scarring of the lungs from asbestos fibers, which makes breathing difficult), lung cancer and mesothelioma (a rare form of cancer that affects the lungs, chest, abdomen and heart and is found almost exclusively in people exposed to asbestos). Asbestos exposure has also been linked to gastrointestinal disease. It can take as long as 30 years before health effects related to asbestos exposure are seen, estimates the ATSDR.