Assessing welding fume exposure in professional welders: An exploratory study of biomarkers and metabolomic profiles

Welding fumes exposure is associated with various detrimental health consequences including cardiopulmonary diseases and cancer. We assessed welding fume exposure using biomonitoring, metalomics, and metabolomics. 38 professional welders (exposed) and 36 power line technicians (non-exposed) were recruited from various facilities in Alberta, Canada. Air sampling and urine collection were conducted. Metal levels were quantified using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Metabolites were quantified using Liquid Chromatography tandem Mass Spectrometry (LC-MS-MS). Receiver operating characteristic (ROC) curve analysis and linear mixed models (LMM) were performed using STATA 19.0 and MetaboAnalyst 5.0. Short-term and cumulative doses were calculated using air sampling data in the modified Environmental Protection Agency (EPA) method. Elevated urinary levels of As, Cr, Fe, Mn, and Ni were observed in welders than in the non-exposed group (p˂0.05). Among the metabolites, beta-hydroxybutyric acid, arginine, asparagine, choline, and ornithine were proposed as potential biomarkers for welding fume exposure (AUC>0.7). ROC results identified metabolites associated with welding experience and smoking. LMM identified smoking as the main predictor of urinary Fe, Mn, and V, while short-term Cr and Sb doses predicted their urinary levels; welders' urinary metabolites were mainly influenced by welding experience and smoking. Our study highlights the potential benefits of biomonitoring and metabolomics to assess the health effects of welding fume exposure. However, relatively small sample size and lacking biomarkers exploration by sex limit the generalizability of findings. Further investigation is recommended to explore the underlying mechanisms and the effects of other factors on the metabolomics profile in professional welders.