Respiratory symptoms and pulmonary function of welders in the engineering industry.

We have studied respiratory symptoms, smoking habits, chest radiographs, sickness absence, and pulmonary function among 258 welders and an equal number of matched control subjects in three engineering factories. Welders who smoked had a higher frequency of chronic phlegm production than control subjects but there was no difference in cough or dyspnoea. The frequency of abnormality on chest radiographs was low and similar in welders and controls. Upper respiratory infections were a more frequent cause of sickness absence in welders than in controls but no difference was found in other respiratory diseases. FEV1 and peak expiratory flow rate were similar in welders and controls. In a subset of 186 subjects the maximum expiratory flow rate at low lung volumes was significantly less in welders who smoked than in control subjects who smoked, but there was no difference in non-smokers. Welders working under these conditions in the engineering industry appear to have no increased risk of chronic obstructive lung disease.