Occupational exposure to amorphous silica nanoparticles alters lung function and metabolomic features

Amorphous silica nanoparticles (SiNPs) are widely produced and used nanomaterials. Although studies have extensively documented SiNPs-induced pulmonary injuries in animal models, the adverse effects on humans remain unclear due to a lack of epidemiological research. In this population-based study, we investigated the effects of occupational exposure to SiNPs on pulmonary function and serum metabolites and explored correlations between these outcomes. We included 15 workers exposed to SiNPs and 45 healthy adults. Chest X-radiography revealed abnormalities such as disordered lung markings and increased lung markings in exposed workers. Pulmonary function parameters, including forced vital capacity (FVC), forced expiratory volume at 1 s (FEV₁) and forced expiratory flow at 25-75 % (FEF_{25 %-75 %}) were significantly lower in the exposed group compared with controls. We used untargeted high-resolution metabolomics to analyze serum metabolites and identified 15 significantly altered metabolites, primarily categorized as lipids and amino acids. Metabolic pathway analysis suggested that SiNPs exposure may disrupt tryptophan metabolism, phenylalanine metabolism, and sphingolipid metabolism. We used Spearman correlation analysis to evaluate relationships between metabolites and pulmonary function. Six metabolites, particularly the environmental pollutants TEMPO and PFOS, showed significant associations with lung function parameters. Therefore, SiNPs may alter the absorption and metabolism of other environmental pollutants. Overall, occupational exposure to SiNPs may impair lung function and disrupt serum metabolite profiles.