Asbestos-related illness usually arises at least 10 to 20 years after initial exposure. In many instances, patients may be unaware of the source of exposure. Although community-based exposures are unusual, recent events indicate that both communities and workers may have had significant exposure to asbestos contained within vermiculite. Physicians should obtain a medical history as outlined above when examining workers or community members who believe they have been significantly exposed to vermiculite. In addition, pulmonary function testing and chest radiographs should be obtained. If these are normal and there is no ongoing exposure, it is likely that no further evaluation is required. Physicians should have a radiologist familiar with occupational lung diseases read films. Patients may ask that a "B" reader, a physician who is certified by the National Institute for Occupational Safety and Health to read x-rays for changes related to the pneumoconioses, review their films. Facilitating smoking cessation and providing routine immunizations are important secondary preventive measures. Workers exposed to asbestos should receive ongoing screening as specified by the Occupational Safety and Health Administration. Over the last several decades, numerous epidemiologic studies have evaluated the efficacy of lung cancer screening. Period chest radiographs and sputum cytology have not been shown to increase lung cancer survival rates. Recent studies have demonstrated the potential benefit of scanning in the early detection of lung cancer. Although encouraging, these studies do not yet support the use of imaging for the routine screening of high-risk populations as required by the Occupational Safety and Health Administration.