Fibres of Amosite, brown asbestos

Scanning electron micrograph of amosite, brown asbestos. The picture shows the fibrous nature of the crystalline mineral; the finest fibres are less than 1 micron in diameter. Asbestos is a general term for natural fibrous minerals characterised by chemical inertness, resistance to heat and fire, and mechanical strength. They are grouped either as serpentine or amphibole asbestos. Amosite is amphibole; the fibres are brittle and needle-like. When bulk material is damaged, fine fibres are released, presenting a serious health hazard. Breathed in, the fibres can cause asbestosis, which leads to an increased risk of cancer. Now classified as carcinogenic, the use of amphibole asbestos has been banned in the UK since 1985. Asbestos was formerly used in a variety of ways; as insulation, in vehicle brakes, and as fireproof panels. Its safe removal from buildings demands specialist expertise., Photo by DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY