Asbestos is a naturally occurring mineral that was once used extensively in construction due to its insulating and fire-retardant properties. However, it has since been found to be highly toxic and carcinogenic, causing diseases such as lung cancer and mesothelioma.

Asbestos can be present in a wide range of building materials, including insulation, flooring, and roofing. It is particularly common in buildings that were constructed before the 1980s.