Per- and polyfluoroalkyl substances (PFAS) are increasingly recognized as airborne contaminants of concern, yet their distribution across environments remains under-characterized. In particular, con centrations in industrial settings have hardly been studied compared to general environments. This review synthesizes findings from 25 studies reporting airborne PFAS across four categories: outdoor general environments, indoor general environments, outdoor occupational environments, and indoor occupational environments. Reported levels were generally lowest outdoors (0.5—3.0 ng/m3 ), higher in general indoor settings (3.0—15.0 ng/m 3 ), and highest in occupational environments, sometimes exceeding 100 ng/m 3 . Volatile precursors such as fluorotelomer alcohols dominated most environments, while particle-bound ionic PFAS were more common in occupational settings, suggesting distinct exposure pathways. Across studies, airborne PFAS levels were lowest outdoors, higher indoors, and highest in occupational settings. The complexity of PFAS behavior, influenced by chemical species and particle/gas-phase partitioning, underscores challenges in exposure assessment. Despite the relatively low airborne PFAS concentrations, this review confirms that inhalation remains a critical exposure pathway due to the persistence, bioaccumulation, and toxicity of PFAS. Standardized measurement methods, geographically diverse monitoring, and integration with exposure modeling are urgently needed. Strengthening regulatory frameworks and establishing protective exposure limits will be essential to mitigate long-term health impacts.

Background: There is little information about the airborne hazardous agents released during the heat treatment when manufacturing a welding material. This study aimed to evaluate the airborne hazardous agents generated at welding material manufacturing sites through area sampling. Methods: concentration of airborne particles was measured using a scanning mobility particle sizer and optical particle sizer. Total suspended particles (TSP) and respirable dust samples were collected on polyvinyl chloride filters and weighed to measure the mass concentrations. Volatile organic compounds and heavy metals were analyzed using a gas chromatography mass spectrometer and inductively coupled plasma mass spectrometer, respectively. Results: The average mass concentration of TSP was 683.1 ± 677.4 μg/m3, with respirable dust accounting for 38.6% of the TSP. The average concentration of the airborne particles less than 10 μm in diameter was 11.2–22.8 × 104 particles/cm3, and the average number of the particles with a diameter of 10–100 nm was approximately 78–86% of the total measured particles (<10 μm). In the case of volatile organic compounds, the heat treatment process concentration was significantly higher (p < 0.05) during combustion than during cooling. The airborne heavy metal concentrations differed depending on the materials used for heat treatment. The content of heavy metals in the airborne particles was approximately 32.6%. Conclusions Nanoparticle exposure increased as the number of particles in the air around the heat treatment process increases, and the ratio of heavy metals in dust generated after the heat treatment process is high, which may adversely affect workers' health.