Researchers followed a cohort of 17,345 individuals with 20 or more years in the trade, identifying the cause of death in order to examine overall patterns of mortality as well as mortality due to work-related lung diseases including asbestosis, asbestos-related cancers, and COPD (Chronic Obstructive Pulmonary Disease). Sheet metal workers in the sample proved to be at a significantly elevated risk of death from asbestosis, mesothelioma, and pleural cancer. Workers demonstrating asbestosis exhibited higher lung cancer rates, and evidence suggested that asbestos exposures may increase lung cancer risk even in the absence of asbestosis.