Eugene Wassam, age 16, of Phoenix, Arizona, for his question:
Where does asbestos come from?
Asbestos is a fibrous mineral of the earth's crust and until recently we mentioned only its amazing good qualities. Then in October of 1971, it was listed as a possible air pollutant because fragments of its almost indestructible fibers may harm the lungs. Let's hope the problem can be solved by more careful processing techniques. For its insulating, fire and acid resistant qualities make asbestos a lifesaver.
Several silicate type minerals form tight wads of flexible fibers called asbestos. They are found in the earth's natural pressure cookers, where hot springs have deposited their minerals in cracks between layers of various igneous rocks. Valuable deposits occur in the ancient Laurentians and the young mountains of Central Europe. Others are mined from middle aged mountains in Africa and in our Western ranges.
The Greeks and Romans used unburnable asbestos fibers as candle wicks and wove them in fabrics to wrap bodies for cremation. The Emperor Charlemagne had a women asbestos table cloth and liked to startle his guests by tossing it into the fire ¬where it was licked clean by the flames. Our Benjamin Franklin treasured an asbestos purse given to him by Indians of Canada. However, mankind was very slow to appreciate the lifesaving and other remarkable qualities of the asbestos minerals.
In 1710, a deposit in Russia's Ural mountains was mined and processed to make cloth for such items as gloves and purses. But the project failed and asbestos was forgotten for half a century. Then a deposit was found in the Alps and the Italians recognized the fire resistant qualities of asbestos cloth. In 1806, they outfitted a fireman to wear the world's first fireproof asbestos suit.
In 1860, prospectors in Quebec found long silky fibers of top quality asbestos, wadded in thick layers. But production lagged until 1878, when the Italians displayed their asbestos products at the Paris Exposition. At last the possibilities were recognized and the search for asbestos deposits became worldwide.
However, the earth did not create a booming abundance of these minerals. Deposits were found in Rhodesia and the Republic of South Africa. Others are mined in New York and New Jersey, Vermont and at Belvedere Mountain in Arizona. The largest deposits are in Quebec, in an area 70 miles long and six miles wide. Some of the single veins are 800 foot lengths of thick wadded layers.
The modern world processes 2% million tons of asbestos annually, mainly for electrical insulators, acid filters, fireproof tiles and fabrics. Half this supply comes from the Canadian deposits in Quebec. Qualities differ in various asbestos minerals. Short or brittle fibers are matted to make tiles. Long supple threads can be woven. One pound of top quality asbestos can produce six miles of thread to make cloth that can withstand temperatures of 5,000 degrees Fahrenheit. Such qualities deserve our best efforts to produce this valuable mineral without polluting the air.