Asbestos demolition hazard warning. Danger sign warning against an asbestos hazard at a demolition site. Asbestos comprises silicate minerals. It is used as insulation in the building industry. If the asbestos degrades and is exposed, asbestos fibres will be released into the air. These are small and can be inhaled deep into the lungs. As the body is unable to degrade the fibres, they cause lung damage due to asbestos (asbestosis) and lung cancers such as mesotheliomas. This is the demolition of the Brewster-Douglass public housing projects in Detroit, Michigan, USA. Photographed in August 2014.