The effects of zinc- and copper-containing welding fumes on murine, rat and human precision-cut lung slices

Recently, the pro-inflammatory effects of metal inert gas brazing welding fumes containing zinc and copper have been demonstrated in humans. Here, murine, rat and human precision cut lung slices (PCLS) were incubated in welding fume containing media with 0.1, 1, 10 and 100 μg/ml for 24 or 48 h. 24 h incubation were determined either by incubation for the total time or for only 6 h followed by a 18 h post-incubation phase. Cytotoxicity, proliferation and DNA repair rates, and cytokine levels were determined. Welding fume particle concentrations of 0.1 and 1 μg/ml showed no toxic effects on PCLS of all three species, while for 10 and 100 μg/ml a concentration-dependent toxicity occurred. Proliferation and DNA repair rates were reduced for all tested concentrations and incubation times. Additionally, the cytokine levels in the supernatants were markedly reduced, while after 6 h of exposure with 18 h of post-incubation time a trend towards increased cytokine levels occurred.