Airborne microplastics from plastic manufacturing industry: Concentrations and characterisation using Py-GC/MS and hyperspectral analysis

Microplastics (MPs) pollution has emerged as a critical environmental concern due to its ecological impacts and health hazards. Previous studies have confirmed the presence of MPs in various environmental media, including the atmosphere. However, research on airborne MPs contamination in occupational places, particularly in plastic manufacturing industry, remains limited. The objective of our research was to investigate and analyze the exposure characteristics of airborne MPs in the plastic manufacturing industry through pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and hyperspectral imaging (HSI) analysis. The analytical results revealed that the types of raw materials used in factory production were identified as the main components of airborne MPs, which predominantly existed as particulate matter, characterized by small sizes (<10 μm). In terms of concentration, the airborne MPs in the crushing workshop exhibited the highest (43.57 ± 39.85 μg/m³), followed by the injection molding workshop (19.37 ± 7.38 μg/m³), workshop office (9.96 ± 3.69 μg/m³), and outdoor residential area (8.00 ± 0.64 μg/m³). Crushing operators were identified as the high-exposure group in the traditional plastic processing industry. Their MPs 8-hour time-weighted average concentration (C_TWA) was 61.16 μg/m³. It is estimated that male workers aged 18-44 in this crushing position could inhale approximately 117.03 mg/a MPs through occupational exposure. Taken together, occupational exposure is a significant source of MPs inhalation in humans, which is closely associated with production processes and raw materials. Our results provide valuable data for establishing occupational health standards, formulating preventive and control strategies and further studies on occupational health risks assessment of MPs.