|Description:||Magnified 500X, this scanning electron microscopic (SEM) image revealed some of the microcrystalline ultrastructure exhibited by a piece of raw chrysotile, or white asbestos, which had been excavated from the Lowell Asbestos Mine on Belvidere Mountain, Vermont.|
Note the elongated crystalline structure, and how the fibrils are arranged in both bundles, and as singular serpentine units. See PHIL 11034 through PHIL 11066, for additional photomicrographic views of this material.
Though chrysotile asbestos is the predominant commercial form of asbestos, asbestos is the name given to a group of six different fibrous minerals including chrysotile, amosite, crocidolite, and the fibrous varieties of tremolite, actinolite, and anthophyllite, with all occurring naturally in the environment. Note that the fibers are configured in both lamellated and teased patterns, which illustrates the long, flexible nature of this mineral’s fibers.
Workers who repeatedly breathe in asbestos fibers with lengths greater than or equal to 5µm may develop a slow buildup of scar-like tissue in the lung, and in the membrane that surrounds the lungs. This scar-like tissue does not expand and contract like normal lung tissue and so breathing becomes difficult. Blood flow to the lung may also be decreased, and this causes the heart to enlarge. This disease is called asbestosis. People with asbestosis have shortness of breath, often accompanied by a cough. This is a serious disease and can eventually lead to disability, or death in people exposed to high amounts of asbestos over a long period. However, asbestosis is not usually of concern to people exposed to low levels of asbestos. Changes in the membrane surrounding the lung, called pleural plaques, are quite common in people occupationally exposed to asbestos, and are sometimes found in people living in areas with high environmental levels of asbestos.