Welding fumes toxicity assessment using an automated welding platform, a dynamic exposure technique and human-derived cells

摘要

Welding consisted of a hazardous process involving high temperatures (to join metals together) and generating toxic fumes in the process. Therefore, welders were exposed to many occupational hazards. Numerous studies reported a range of health dangers associated with exposure to welding fumes although they did not provide definitive human toxicology data as they mainly depended on animal studies. The main concerns from welding were from complex mixtures of metal fumes and toxic gases like ozone, carbon monoxide and nitrogen oxide that were generated during the process. The potential toxicity of generated welding fumes was influenced by welding parameters such as welding length, duration, wire feed speed and types of material being welded. The aim of this study was to assess the cytotoxicity effects of mild steel (MS) and stainless steel (SS) welding fumes, on human lungs by using human-derived lung cells A549. This study simulated the welding environment through design and construction of an automated welding platform which operated for 30 – 60 minutes. The generated fumes were channelled to an in vitro dynamic exposure setting consisting of A549 cultured on Snapwell membranes. The presented data resulted from assessing cytotoxicity using MTS 3-(4,5-dimethylthiozol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. The assay was applied 0 and 24 h post exposure. Welding generated particles were also collected during exposure, and elemental composition was determined using ICP-AES. The results showed that the generated SS-fumes contained Fe, Mn, Cr and Ni while MS-fumes produced mainly Fe and Mn. Wire fed speed influenced fumes generation and cell viability reduction as the welding duration was longer. However, welding length and types of consumables had no significant impact on cell viability.