Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders

Abstract

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.

Nano- and neurotoxicology: An emerging discipline

“…In 2014, Andujar et al found predominantly iron of around 20-25 nm, but also chromium and/or manganese, titanium, aluminum, silica and nickel in the lung tissue sections of welders (Andujar et al, 2014). Regarding tungsten inert gas welding, Graczyk et al (2016a) (Graczyk et al, 2016a) reported that iron was a minority among elements measured at the welders' breathing zone, mostly composed of aluminum and tungsten nanoparticles of 45 nm in average. However, Miettinen et al (2016) reported that percentages of Fe, Mn, Cr, Ni, and Mo of the total particle mass collected were 8.7, 2.7, 2.6, 1.4, and 0.3%, respectively, with multimodal particle size distribution in the range of 10-30 nm (Miettinen et al, 2016).…”

On‐site three‐dimensional printer aerosol hazard assessment: Pilot study of a portable in vitro exposure cassette

“…. The concentrations in their study and this study are small in comparison with other nanoparticle aerosol generating processes, such as tungsten inert gas welding . Because the metal powder used by Graff et al .…”

Evaluation of ceramic flexural strength of a cobalt-chromium alloy subjected to airborne particle abrasion and tungsten inert gas welding

“…Although the conventional brazing technique is more used in dentistry, studies have demonstrated the superiority of tungsten inert gas (TIG) welding 15,16 . This process uses an electric arc formed between a non-consumable tungsten electrode and the part to be fused and applies an inert gas (argon or helium) to provide local protection to prevent oxidation [17][18][19][20] . In this type of welding, heating is concentrated and disorders and deformation are minimized; furthermore, there is an increase in corrosion resistance due to the lack of galvanic effects in the joint 17 .…”