Chronic occupational exposure to metals in welding fumes has been implicated in the etiology of neurodegenerative diseases (NDDs), including Parkinson's disease (PD) and Alzheimer's disease (AD). Changes in microRNA (miRNA) expression have been associated with various neurodegenerative conditions. Circulating miRNAs, in particular, have emerged as promising, minimally invasive biomarkers for diagnosing and monitoring disease progression. This study was designed to characterize the expression of miRNAs in neuronally-enriched serum extracellular vesicles (EVs) among welders and non-welders to explore their potential link to metal concentrations and welding exposure measures and their potential as early diagnostic biomarkers for neurodegeneration. Serum samples from 39 welders and 27 healthy individuals were collected, and EV-enclosed miRNAs were extracted and analyzed. Also, whole blood metal concentrations and welding exposure measurements were obtained. Fifty miRNAs were found to be dysregulated in welders