High variability in toxicity of welding fume nanoparticles from stainless steel in lung cells and reporter cell lines: the role of particle reactivity and solubility

Abstract

Millions of people in the world perform welding as their primary occupation resulting in exposure to metal-containing nanoparticles in the fumes generated. Even though health effects including airway diseases are well-known, there is currently a lack of studies investigating how different welding setups and conditions affect the toxicity of generated nanoparticles of the welding fume. The aim of this study was to investigate the toxicity of nine types of welding fume particles generated via active gas shielded metal arc welding (GMAW) of chromiumcontaining stainless steel under different conditions and, furthermore, to correlate the toxicity to the particle characteristics. Toxicological endpoints investigated were generation of reactive oxygen species (ROS), cytotoxicity, genotoxicity and activation of ToxTracker reporter cell lines. The results clearly underline that the choice of filler material has a large influence on the toxic potential. Fume particles generated by welding with the tested flux-cored wire (FCW) were found to be more cytotoxic compared to particles generated by welding with solid wire or metal-cored wire (MCW). FCW fume particles were also the most potent in causing ROS and DNA damage and they furthermore activated reporters related to DNA double-strand breaks and p53 signaling. Interestingly, the FCW fume particles were the most soluble in PBS, releasing more chromium in the hexavalent form and manganese compared to the other fumes. These results emphasize the importance of solubility of different metal constituents of the fume particles, rather than the total metal content, for their acute toxic potential.

ToxTracker Reporter Cell Lines as a Tool for Mechanism-Based (Geno)Toxicity Screening of Nanoparticles—Metals, Oxides and Quantum Dots

“…No effect was observed on the p53-responsive Btg2-GFP reporter for either QDs or soluble CdCl 2 (Figure 8). These findings can be compared to previous studies, where welding fume NPs were the only NPs that resulted in an activation at comparable levels, approximately 4-fold [13]. In addition, NiO NPs were seen to induce the Btg2-GFP reporter in the first study by Karlsson et al [10].…”

“…Exposure to the Mn NPs resulted in an activation of the Bscl2 just above the 2-fold threshold ( Figure 6). As of now, none of the other NPs investigated in this or previous studies, in total 32 different NPs [10][11][12][13] has clearly induced the Bscl2 reporter. This indicates that most likely none of the tested NPs, or released metal species, could bind directly to DNA and cause stalled replication forks.…”

“…A marginal increase was also observed in response to V 2 O 5 NPs, although at rather cytotoxic doses (40-50%), whereas no induction was observed for the V NPs ( Figure 6). In our previous studies, CuO (unpublished), Co, and CoO NPs [12] as well as welding fume NPs [13] have activated the Rtkn reporter at magnitudes ranging from 2 to 3-fold increase. A slight increase (above 1.5-fold) was also observed for Cr 2 O 3 NPs, as also previously observed for Ni and NiO NPs [11].…”

“…In addition, a weaker yet positive (or borderline) induction was observed for the QDs of sizes 2.6, 6.5 and 8.6 nm while the soluble CdCl 2 salt resulted in a 3.5-fold increase ( Figure 5). None of the previously studied NPs has been found to activate this marker [11][12][13].…”

Mild steel and stainless steel welding fumes elicit pro‐inflammatory and pro‐oxidant effects in first trimester trophoblast cells

“…Both Fe and Mn, which are present in all three welding fume samples, are known contributors of oxidative stress. In a study conducted by McCarrick et al, in which they also studied welding fume cytotoxicity, a direct correlation between ROS production and Mn ( R 2 = .92) was observed. Fe is also well known for reacting with hydrogen peroxide, which generates • OH via the Fenton reaction.…”