Rapid progression of pleural disease due to exposure to Libby amphibole: "Not your grandfather's asbestos related disease"

Background: Residents and mine employees from Libby, Montana, have been exposed to asbestiform amphiboles from the vermiculite mine that operated in this location from the mid-1920s until 1990. Clinical observations show a different form of asbestos-related toxicity than other forms of asbestos. Methods: Five illustrative cases from the Center for Asbestos-Related Diseases in Libby were selected. All had clear exposure histories, multiple follow-up visits, illustrative chest radiographic studies, serial pulmonary function tests, and sufficient length of follow-up to characterize disease progression. Results: These cases developed increasing symptoms of dyspnea and chest pain, progressive radiological changes that were predominantly pleural, and a restrictive pattern of impaired spirometry that rapidly progressed with significant loss of pulmonary function. Conclusions: LA exposure can cause a non-malignant pleural disease that is more rapidly progressive and more severe than the usual asbestos-related disease.