Asbestos is a set of six naturally occurring silicate minerals, which all have in common their thin fibrous crystals, with each visible fiber composed of millions of microscopic “fibrils” that can be released by abrasion and other processes. They are commonly known by their colors, as blue asbestos, brown asbestos, white asbestos, and green asbestos.
In The Wizard of Oz, Dorothy (played by July Garland), along with the Scarecrow, the Cowardly Lion, and the Tin Man, were snowed on by chrysotile (or ‘white’) asbestos fibers.
The fake snow created contained 100% industrial-grade chrysotile asbestos fibers, and anybody who came into contact with this material inhaled it in quantities similar to those working in asbestos mines.
Asbestos mining existed more than 4,000 years ago, but large-scale mining began at the end of the 19th century, when manufacturers and builders began using asbestos for its desirable physical properties.
Some of those properties are sound absorption, average tensile strength, affordability, and resistance to fire, heat, and electricity. It was used in such applications as electrical insulation for hotplate wiring and in building insulation. When asbestos is used for its resistance to fire or heat, the fibers are often mixed with cement or woven into fabric or mats. These desirable properties made asbestos very widely used.
In the early 1900s researchers began to notice a large number of early deaths and lung problems in asbestos-mining towns. The first such study was conducted by H. Montague Murray at the Charing Cross Hospital, London, in 1900, in which a postmortem investigation of a young man who had died from pulmonary fibrosis after having worked for 14 years in an asbestos textile factory, discovered asbestos traces in the victim’s lungs.