97 Toxicity of welding fumes produced by gas metal arc welding and handheld laser beam welding

Abstract Exposure to welding fumes can lead to respiratory diseases. Chronic exposure has been associated with adverse health outcomes, including various respiratory diseases and cardiovascular effects. However, cardiovascular effects are not understood as well as respiratory diseases. In this study, we investigated the toxicity of welding fumes produced by Gas Metal Arc Welding (GMAW) and Handheld Laser Beam Welding (HLBW). For both processes we used mild steel, stainless steel, and aluminium as base materials. Different electrodes were tested for each base material. Welding fumes were collected on glass fibre filters in a testing chamber. Samples were sent at the ORPHY laboratory in Brest where toxicity studies were performed. Cytotoxicity was evaluated using the CellTiter-Glo® test. Embryonic cardiac cells H9c2 were exposed to various concentrations of welding fumes. Oxidative stress was evaluated using the ROS detection assay KIT Ozbiosciences. Bioluminescence and fluorescence were measured using spectrofluorimetry after 24 h of exposure. Preliminary results show that all welding fumes were cytotoxic to the H9c2 cells at concentrations above 5 μg/mL. For GMAW, aluminium fumes were less toxic than mild steel or stainless-steel fumes. In general, HLBW fumes were more toxic than GMAW fumes, possibly because the particles size might be smaller for HLBW than for GMAW due to the lower emission during HLBW process resulting in lower aggregation of particles. However, when testing for reactive oxygen species (ROS), none of the fumes produced ROS suggesting another mechanism might be responsible for the cytotoxicity. Further testing on mitochondrial respiration showed that this cell process was affected by exposure to welding fumes.