Mesothelioma and asbestos exposure in Libby

For much of the twentieth century, a vermiculite mine on Zonolite Mountain outside Libby supplied a large share of the country's vermiculite. The ore contained a toxic form of amphibole asbestos, often called Libby amphibole. Miners and mill workers were exposed on the job, and dust spread into town through processing, transport and material brought home. Vermiculite was also used locally in gardens, running tracks and home insulation. Workers at the mine and mill often came home covered in dust, and families shared cars, laundry and living space with that dust every day. Children in town played in areas where vermiculite had been used.

Because exposure reached so many people outside the mine, Libby residents with no mining history have developed asbestos-related disease. The federal government declared a public health emergency for the area and led a long cleanup. A local clinic now specializes in asbestos-related disease, and a special Medicare provision helps some people with asbestos disease linked to the Libby area. Vermiculite from the mine was also shipped nationwide and used in attic insulation sold for many years. People who lived in Libby for only a few years can still have been exposed. Because these fibers are considered especially harmful, doctors who treat Libby patients pay close attention to residence history as well as work history when evaluating symptoms.