More than 12 million Americans suffer from a form of COPD (Chronic Obstructive Pulmonary Disease) such as bronchitis and emphysema. Most cases are associated with smoking, but occupational exposures are another important risk factor. Researchers examined detailed medical and work histories, as well as X-rays, for 3944 current and former Sheet Metal Workers whose work tasks were associated with exposure to respirable silica, asbestos, wood and cement dusts, fiberglass, paints and other established respiratory hazards. The data, collected as part of a medical screening program, enabled investigators to link specific occupational tasks to increased COPD risk.