WELDING FUMES TOXICITY ASSESSMENT USING AN AUTOMATED WELDING PLATFORM, A DYNAMIC EXPOSURE TECHNIQUE AND HUMAN-DERIVED CELLS

350 words maximum: 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-(3carboxymethoxyphenyl)-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 MSfumes 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. Declaration relating to disposition of project report/thesis I am fully aware of the policy of the University relating to the retention and use of higher degree project reports and theses, namely that the University retains the copies of submitted for examination and is free to allow them to be consulted or borrowed. Subject to the provisions of the Copyright Act 1968, the University may issue a project report or thesis in whole or in part, in Photostat or microfilm or other copying medium. Signature Witness Date Certificate of Originality i Certificate of Originality I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any degree at UNSW or any other educational institution, except where due acknowledgment is made in the thesis. Any contribution made to the research by others, with whom I have worked, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project’s design and conception or in style, presentation and linguistic expression is acknowledged.