Objectives: It has been shown that exposure of subjects to emissions from a metal inert gas (MIG) brazing process of zinc-coated material led to an increase of high-sensitivity C-reactive protein (hsCRP) in the blood. In this study, the no-observed-effect level (NOEL) for such emissions was assessed.
Methods: Twelve healthy subjects were exposed for 6 hours to different concentrations of MIG brazing fumes under controlled conditions. High-sensitivity C-reactive protein was measured in the blood.
Results: For welding fumes containing 1.20 and 1.50 mg m−3 zinc, high-sensitivity C-reactive protein was increased the day after exposure. For 0.90 mg m−3 zinc, no increase was detected.
Conclusions: These data indicate that the no-observed-effect level for emissions from a MIG brazing process of zinc-coated material in respect to systemic inflammation is found for welding fumes with zinc concentrations between 0.90 and 1.20 mg m−3.