Interstitial pulmonary fibrosis after severe exposure to welding fumes

Background Interstitial pulmonary fibrosis (IPF) is reported after long term, severe exposure to welding fumes in poorly ventilated workplaces. Methods Fifteen welders with IPF were examined-13 in our outpatient clinic-from 1990 to 1997. Occupational histories and examinations, lung function analyses, symptoms and clinical findings, histological analyses in 13 patients partly including SEM/EDX-analyses, chest X-rays, chest computed tomographies were conducted. Results Duration of work as welders was 28 years and the cumulative dose of welding fumes 221 mg/m(3) x years (median). Lung function studies found pattern of restriction or combined restriction-obstruction, lower diffusion capacity, and reduced blood oxygen tension at exercise. Histologicallly, patchy interstitial fibrosis was noted. Accumulations of particulate matter typically for welding fume were detected. EDX showed increase of iron load and close topographical relationship to welding fume particles embedded in areas of scattered fibrosis. Conclusion While epidemiological data are limited, it is reasonable to conclude that a causal relationship exists between IPF in welders with long term exposure to high concentrations of welding fumes. (C) 2002 Wiley-Liss, Inc.