These are permits and courtesy notifications for the removal of asbestos-containing materials from structures in Louisville/Jefferson County, Kentucky, issued by the Louisville Metro Air Pollution Control District. A permit is required if someone is are disturbing or removing asbestos-containing material from any structure other than their own home. Also, anytime someone is demolishing a building, they will likely need to send in a notification and may need a permit to remove asbestos before the demolition. Asbestos is a general term for a group of fibrous minerals (primarily chrysotile, amosite and crocidolite) that have long been used as fireproof insulation and as a strengthener in pipe insulation, roofing tiles, floor tiles,wall coverings and other materials. Undisturbed asbestos-containing material (ACM) is not dangerous. But when asbestos-containing material is broken or torn, as during remodeling or demolition, the fibers can be spread into the air, especially if the material is friable (crumbly). Studies have shown that inhaling high concentrations of these fibers can over time cause a disease called asbestosis, lung cancer and another type of cancer called mesothelioma. In asbestosis, delicate lung tissue is damaged by the body's own attempts to remove embedded fibers. Mesothelioma can develop in the lining (pleura) of the lung or in the lining of the abdomen (peritoneum). Symptoms of lung cancer or mesothelioma usually do not appear for 15 to 30 years after exposure; for asbestosis, the latency period is 25 to 40 years. Special training and equipment are required to remove asbestos-containing material safely. For this reason, federal and local regulations require a permit and the use of a licensed contractor for removal of asbestos-containing material from any structure other than a private residence.