The Effects of Repeated Exposure to Zinc- and Copper-Containing Welding Fumes on Healthy Volunteers

OBJECTIVE: Recently, the proinflammatory effects of welding fumes containing zinc and copper have been demonstrated. In the present study, it was investigated if the inflammation persists under repeated exposure. METHODS: Fifteen healthy male subjects were exposed to 6 hours of exposure with zinc- and copper-containing welding fumes on 4 consecutive days under controlled conditions. RESULTS: Inflammatory marker serum levels showed significant increases compared with baseline either 6 or 24 hours after the first exposure and stayed elevated for all following exposures. In nasal secret samples only C-reactive protein levels were increased compared with baseline. CONCLUSIONS: The current study demonstrates a persistent increase of systemic inflammatory markers indicating an elevated risk for welders chronically exposed to zinc- and copper-containing welding fumes. Topical inflammation of the upper airways did not occur.