By Dr. Richard Lemen
Asbestos is a commercial term referring to a group of naturally-occurring fibrous minerals. Asbestos has remarkable durability and resistance to heat, properties conferring value in a wide range of products including building and pipe insulation, friction products including brake shoes, and fire-resistant bricks. Asbestos has been woven into fireproof cloth and incorporated into cement pipes used for water transport and into erosion-resistant cement roofing tiles. Unfortunately, asbestos fibers are also inhalable, and once inhaled, cause grave health risk, apparently because of their physical characteristics and bio-persistence in the body. Asbestos exposure causes a wide range of serious and fatal health conditions including pleural changes (plaques, thickening, breathlessness, loss of lung function), asbestosis (scarring of the lungs), cor-pulmonale (right sided heart enlargement and then failure), lung cancer, mesothelioma (cancer of the linings of the lung or abdomen), laryngeal cancer, gastro-intestinal cancers (including stomach, colon, recital), ovarian cancer, and is suspected of causing kidney cancers.
All asbestos fiber types have been found to cause all major types of asbestos-related disease, including chrysotile, the most commonly used form of asbestos. In reality, most asbestos use involves either intentional mixing of different fiber types or inadvertent contamination of a fairly pure product with small quantities of another (natural contamination). Today world production of asbestos is highest from Brazil, Canada, China, Kazakhstan, Russia, and Zimbabwe. Vast amounts of asbestos are still used in many developing countries where exposure is not limited to just workers, by also non-occupational groups including children. For these reasons and because scientists have not been able to determine a safe level of exposure to asbestos most industrial countries have banned its use. However, this has not been true for Canada or the United States where products can still contain asbestos.
Dr. Richard Lemen is the Retired Assistant Surgeon General and serves as ADAO Science Advisory Board Co-Chairman Dr. Lemen will be presenting at the Asbestos Awareness Conference on April 2, 2011. http://www.asbestosdiseaseawareness.org/adao-conference/