Asbestos is classified into 2 groups based on its physical properties: the serpentines, which tend to be wavy and long, and the amphiboles, which are straight and rodlike. The most important member of the serpentines is chrysotile, which makes up more than 90% of the asbestos used in the United States. The amphibole group includes crocidolite, amosite, and tremolite, which is often found as a contaminant of chrysotile ore.
The use of asbestos can be traced through history as far back as the Stone Age, when it was mixed in with earthenware pots for strength. Though the versatility of asbestos has been known since ancient times, its use did not become widespread until the Industrial Revolution in the late 19th century, when mass quantities were needed for booming textile and insulation factories. Asbestos production increased during the next century until its peak in the 1970s. Despite the well-documented health risks from exposure, asbestos remains widely used, particularly in developing countries.
Three major diseases are associated with asbestos exposure: asbestosis, lung cancer and mesothelioma. Pleural plaques are the most common manifestation of exposure. This article focuses on asbestosis, which specifically refers to the bilateral diffuse interstitial fibrosis of the lungs caused by inhalation of asbestos fibers. (more…)
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