The author has been engaged in a long-term observation of the group of 111 electro-welders whose average duration of work at risk lasted 25 years. The x-ray picture of the subjects was dominated by opacities, p, q, frequency 1, 2 according to the ILO classification. Following the 11 years of observation there was a partial regression of the X-ray changes. Forty two persons were completely shelved from the work, regression of their X-ray changes developed in 36% during the observation of about nine years on the average. In 11 men the open pulmonary biopsy was performed, showing iron deposits in all cases. In seven of them a minor non-collagen reaction of the lung tissue to the dust was detected, the finding being evaluated as pneumoconiosis from welding. The fibrosis of uncertain etiology was diagnosed in six per cent on the average, bronchogenic cancer in nine per cent of the observed individuals. Chronic bronchitis was present in 48% of the cohort at the end of the period of observation. Twenty five persons died, 60% of them as a result of lung disease (bronchogenic cancer developed in 32%, cor pulmonale in 28% as a consequence of chronic lung disease or lung fibrosis). The mean age at the time of death was 59 years. These findings draws attention to a potential risk of welder occupation.

        Key words: welders, X-ray picture, development of the disease, histology, chronic bronchitis, interstitial lung fibrosis, bronchoge- nic cancer, cause of death