Graczyk Halshka, Lewinski Nastassja, Zhao Jiayuan, Concha-Lozano Nicolas, Riediker Michael
1.Institute for Work and Health, University of Lausanne and Geneva, 1066 Epalinges-Lausanne, Switzerland;
1.Institute for Work and Health, University of Lausanne and Geneva, 1066 Epalinges-Lausanne, Switzerland; 2.Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA;
Ann Occup Hyg. 2016 Mar;60(2):205-19. doi: 10.1093/annhyg/mev074. Epub 2015 Oct 12.
Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm(-3), with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training.
钨极惰性气体保护焊（TIG）是工业中应用最广泛的金属连接工艺之一。它在纳米尺度上产生较大比例焊接烟尘颗粒的倾向，对工人构成了潜在的职业健康危害。然而，目前的文献缺乏对TIG焊接烟尘颗粒的全面表征。对于几乎没有焊接经验的焊接学徒所产生的焊接烟尘，了解得更少。我们对在通风暴露舱内的学徒焊工（N = 20）产生的TIG焊接烟尘进行了表征。对每个学徒焊工在焊接面罩内的呼吸区（BZ）以及距离焊接作业60厘米的近场（NF）位置进行了暴露评估。我们对颗粒物（PM4）、颗粒数浓度和粒径、颗粒形态、化学成分、活性氧（ROS）产生潜力以及气态成分进行了表征。BZ处的平均颗粒数浓度为1.69E+06个颗粒/立方厘米，平均几何平均直径为45纳米。在所有受试者中，平均而言，BZ处92%的颗粒计数低于100纳米。我们观察到钨的浓度升高，这很可能是由于电极消耗所致。BZ处TIG焊接烟尘的平均ROS产生潜力超过了先前在交通污染空气中发现的平均浓度。此外，在焊接作业中烧损金属的学徒的ROS产生潜力明显更高。我们建议未来的暴露评估应将焊接性能作为学徒焊工或培训极少的焊工潜在的暴露修正因素加以考虑。
