Airborne Microplastics in Workplaces: Preliminary Findings from a Multi-site Investigation of Plastic Handling and Processing Facilities

Airborne microplastics (AMPs) are emerging contaminants of increasing global concern due to their persistence, small size, and potential for inhalation, allowing them to reach the human respiratory system. Although current evidence suggests possible risks to respiratory health, the actual extent of the hazard to the general population remains unclear. Given these characteristics and the associated health risks, particular attention must be paid to environments where AMP exposure levels may be elevated.1 Therefore, we selected different work environments involving the handling and mechanical processing of plastic materials to assess the relevance of occupational exposure to AMPs. The experimental design involved sampling in five different industrial facilities, each characterized by different plastic material workings ranging from mechanical-biological processing of mixed municipal waste to plastic waste sorting, secondary raw material production, and processing of single polymers. At each site, five representative sampling locations were selected to capture different exposure scenarios: (1) a primary processing area with intense mechanical operations; (2) a secondary area with less intensive activities; (3) an office area, physically separated from production, serving as an indoor background; (4) a personal sampling point, using wearable devices to estimate individual exposure during work shifts; and (5) an outdoor control. Two parallel ambient air samples were collected at each location using low-flow pumps (15 L/min) equipped with total dust sampling heads. Following sampling, a dual analytical approach, specifically developed for AMPs, was set up, combining Py-GC-MS and fluorescence microscopy to integrate quantitative data on both particle number concentration (particles/m³) and polymer mass concentration (µg/m³). Preliminary results, obtained from two of the five plastic facilities investigated, show higher concentrations of AMPs within the indoor environments compared to outdoor controls. Within indoor spaces, processing areas exhibit elevated levels compared to office spaces confirming the contribution of mechanical plastic transformation activities to AMPs dispersion. Personal sampling of workers engage in direct plastic processing activities reveales higher microplastic concentrations than environmental sampling, indicating that close proximity to cutting and milling significantly increases exposure. Finally, the polymers identified reflect the specific processing activities and the predominant materials handled at each site. 1. Gasperi J., Wright S.L., Dris R., et al. Microplastics in air: Are we breathing it in? Curr. Opin. Env. Sci. Hl. 2018, 1, 1-5.