1. Asbestos or asbestus ( ass-BES-təs, az-, -⁠toss) is a group of naturally occurring, fibrous silicate minerals, used for thousands of years to create flexible objects that resist fire, such as fireproof fabrics, but are now known to be toxic and carcinogenic. There are six types, all of which are composed of long and thin fibrous crystals, each fibre (particulate with length substantially greater than width) being composed of many microscopic "fibrils" that can be released into the atmosphere by abrasion and other processes. Inhalation of asbestos fibres can lead to various dangerous lung conditions, including mesothelioma, asbestosis, and lung cancer. As a result of these health effects, asbestos is considered a serious health and safety hazard. Archaeological studies have found evidence of asbestos being used as far back as the Stone Age to strengthen ceramic pots, but large-scale mining began at the end of the 19th century when manufacturers and builders began using asbestos for its... from wikipedia.org