Toxicity of electric arc welding fumes. III. Experimental studies on welder's fever.

Abstract

In order to pursue the cause of welding fume-generated fever, rabbits were given fume suspen-sion which was subjected to pretreatments- (1) centrifugation, (2) prolonged storage at room temperature, (3) boiling, (4) heat-desiccation, and (5) freeze-desiccation-and the development of fever was observed. Furthermore, body temperatures, brain temperatures, blood pressures of rabbits and catalase activity in the liver of rats were measured to determine the relation of the fume pyrogen to some of the temperature-regulating factors such as the autonomic nervous system and Fe-related enzymes (magnetic, oxidation-reduction and metal enzymes).A water-soluble fraction fume suspension failed to develop fever in rabbits, while a water-insoluble fraction showed pyrogenecity. Thus this pyrogenic agent was relatively thermo-stable, but became inactive when desiccated by heat (freeze-desiccation did not prevent the activity). Rabbits developed fever a few minutes after the administration of lipopolysaccharide, and a rise in brain temperature preceded that of rectal temperature. However, a rise in brain temperature did not precede after fume administration, and the latent period was longer, and the liver catalase activity was somewhat affected. Moreover, the catalase blocker reduced fume-generated pyrexia. It was suggested that the pyrogenic activity of the intravenously injected fumes might not be central but might affect the metabolic mechanism, and that the pyrogenic factor in the welding fume might be changed physically in its structure when heated in dehydrated state, and the pyrogenecity would vanish due to this physical change.