Febrile attacks were noticed among workers employed in electric welding of galvanized iron pipe in the holds of a boat. Hygienic and medical studies on the work-environment and the workers themselves were carried out. An analysis of the atmosphere of the holds made during the welding revealed high concentrations of zinc oxide (145.7, 69.7 and 14.6 mg/m
3) and dust (81.6 and 245.1 mg/m
3) which were inversely proportional to the area (height × width) of the entrance of the hold. Febrile attacks occurred several hours after the close of the welding work. Most of the cases complained of fever and chill. The other complaints were arthralgia, general malaise, myalgia, irritation of the throat and discomfort in the chest, while others complained of nausea, vomiting and diarrhoea. Recurrence of the attack was characteristic in most of the cases. Patch tests for zinc oxide were positive in 2 out of 49 cases tested. From the above-mentioned results, it is concluded that these febrile attacks were metal fume fevers caused by inhaling zinc oxide. Besides, to see the effects of the metal dust on the lung roentgenographic and spirometric examinations were done. In about half of 66 welders, punctiform opacities in the lung field were observed, the size of which was smaller than that of those found in the usual pneumoconiosis. And, there was no evidence of disturbance of ventilatory functions.
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