Welding and burnishing dusts' exposure characteristics and health risk assessment in electromechanical processing workshop: Based on oxidation potential and EPA

Welding and burnishing are standard industrial processes where workers can be highly exposed to dust for long periods. Current research on dust-related health risks primarily focuses on concentration, often overlooking the combined impact of particle size distribution and chemical composition. This study aims to reveal the relationship between the characteristics of industrial dust (concentration, particle size distribution, elemental composition) and worker health using oxidation potential and EPA health risk assessment methods while quantifying the influence of particle size and elements. We employed a breathing thermal manikin in a Huyi District, Xi'an City, machinery processing plant to simulate worker behaviour. We conducted dust sampling in the breathing zone of welding and burnishing workshops. The oxidative potential (OP) and risk assessment methods were utilized to quantify the potential individual exposure risks to workers. The mass concentration of dust in the welding workshop exhibited a significant unimodal distribution in the 4.7–7 μm particle size range, whereas the burnishing workshop showed a bimodal distribution in the 1.1–2.1 μm and 4.7–7 μm particle size ranges, with no significant seasonal variations observed. The oxidative potential of the dust displayed some similarity to the concentration distribution. Still, under the same concentration conditions, the oxidative potential of welding and burnishing dust differed significantly due to variations in elemental composition. Risk analysis revealed that manganese (Mn) and barium (Ba) had high hazard quotients, indicating non-carcinogenic risks that cannot be ignored. Additionally, despite the extremely low cobalt (Co) content, its carcinogenic risk was also found to be non-negligible.