Asbestos in Transite and Other Building Materials
Originally, the word "transite" was the proprietary brand name of a type of composite siding manufactured by the Johns-Manville Corporation. The original product, introduced in the 1920s, was a mixture of portland cement and asbestos fiber. The addition of asbestos transformed what would ordinarily have been a relatively brittle and heavy material into a durable siding that was lightweight, strong, durable and fire-resistant.
Eventually, "transite" became a generic term for similar cement-asbestos composites produced by many other building material companies. Over the years, transite was used for many purposes other than siding, including roof tiles, jacketing for boilers and steam pipes, and municipal water systems. The latter use has caused widespread health problems in some communities; according to one estimate, there may be as much as 450,000 miles of transite water conduits in towns across Canada and the U.S. One study of a Utah community in which transite pipes carry the municipal water supplies showed elevated rates of kidney and gastrointestinal cancer among the population.
When information on the health hazards of asbestos became widespread in the wake of the discovery of the "Sumner Simpson Papers" in 1977, the use of asbestos in building products was gradually phased out. Asbestos-containing products remained on retail shelves for many years, however.
Hazards Associated with Transite Products
As long as it is intact, transite is not necessarily dangerous. However, like most building materials, it has a tendency to deteriorate over time. Asbestos transite may still be found in hundreds of thousands of old buildings across the U.S., and since most of it is well over thirty years old, it is likely to be friable (a state in which asbestos material crumbles into dust and releases loose fibers into the environment). Appropriate safety precautions must always be taken when working with products that are suspected of containing asbestos.Sources
Bowker, Michael. Fatal Deception: The Untold Story of Asbestos (New York: Touchstone, 2003)
Sadler, Terry D. et. al. "The Use Of Asbestos-Cement Pipe For Public Water Supply and the Incidence of Cancer in Selected Communities in Utah." Journal of Community Health, vol. 9 no. 4 (Summer 1984)