OBJECTIVETo study the character of welder's pneumoconiosis on CT, pathology, and lung function.

METHODSTo contrast 185 welder's pneumoconiosis and 115 silicosis on CT, pathology, and clinical characters which were diagnosed between Jan 2008 and Dec 2013. Chest X-ray and lung function of 39 welder's pneumoconiosis patients were followed up after diagnosed 4~6 years later.

RESULTSAverage age and working years of welder's pneumoconiosis were 36.7 and 11.5, less than silicosis patients 58.8 and 22.1, respectively (P<0.05). Of all 185 welder's pneumoconiosis 98.4% were of stage I and no stage III, while in silicosis group stage I, stage II and stage III were 56.5%, 22.6% and 20.9%, respectively. The ratio differences between the two groups were statistically significant,P<0.05. 82.7% of welder's pneumoconiosis patients were observed pathologically moderate or above dust deposition in lung tissue while interstitial fibrosis level was just mild (97.6% patients) or no fibrosis (2.4% patients). By contrast, 60.0% silicosis patients pathologically showed moderate or above dust deposition while 77.8% were of moderate or above fibrosis. CT findings in welder' s pneumoconiosis were diffuse branching linear structure (38.9%), low density consistent size centrilobular micronodules (19.5%), or both (30.8%). Poorly-defined ground-glass attenuation centrilobular micronodules or widely ground glass shadow were observed in 6.4% welder's pneumoconiosis patents. 30.8% patients failed to reach the original stage when 39 welder's pneumoconiosis followed up chest radiograph.

CONCLUSIONChanges in welder's lung caused by welding fume were not only siderosis, but also interstitial fibrosis.