Asbestos is a naturally occurring mineral that has been used for centuries as an insulating material in buildings and various industrial applications. It was not until the 1970s, however, that its widespread use was recognized as a serious health hazard. Asbestos fibres are extremely small and easily breathed in, leading to respiratory diseases such as asbestosis and lung cancer. The problem is that asbestos is still present in many buildings constructed before the 1990s, putting workers and residents at risk.