Asbestos is a naturally occurring mineral that was commonly used in building materials and products before it was discovered to be highly dangerous to human health. When asbestos-containing materials are disturbed, microscopic fibers are released into the air, which can be inhaled and cause serious health problems, including lung cancer, mesothelioma, and asbestosis. As a result, asbestos was banned in the UK in 1999, but many buildings constructed before this time still contain asbestos.