Study of airborne microplastics emissions in workplaces

Microplastics (MPs) are solid plastics particles composed of mixtures of polymers and functional additives, ranging in size from 1 μm to 5 mm, originating from primary or secondary manufacturing processes. Recently, they have been detected in various environmental compartments, including surface waters, sediments, organisms, soils and the atmosphere. Their presence has attracted the attention of the scientific community, which has classified them as new emerging contaminants (Li et al., 2024), due to their small size, persistence in the environments and ability to adsorb other pollutants onto their surface, as well as to carry plastic additives incorporated during the production process. In reality, airborne MPs are a relatively new topic, as most studies so far have primarily focused on MPs in aquatic and terrestrial environments, which were considered to be at greater risk (Kacprzak et al., 2022). Therefore, knowledge of MPs pollution in the atmosphere is limited. Research on airborne MPs has to largely focus on indoor environments rather than outdoor ones, as most people, on average, spend around 90% of their time in their homes and workplaces (Ouyang et al., 2022). In indoor environments, MPs can be both suspended in the air and present in deposited dust. As a result, exposure can occur through inhalation, ingestion and skin contact, and so they may pose a potential health risk, which has raised global concern. Consequently, the aim of this innovative study, performed within the BRIC ID-14 “Characterization of Emissions in Workplaces of Airborne Microplastics and Nanoplastics” (CELLOPHAN) project, is to investigate the exposure levels of MPs in workplaces, specifically by characterizing them using a combination of spectroscopic and microscopic techniques. In fact, there are currently no standard operation protocols (SOP) for airborne MPs analysis. One of the selected workplaces is a company that deals with plastic bottles blowing and their filling. In this setting, airborne particulate matter was sampled in different work sites. Air samples for plastic analysis were collected onto 47 mm PTFE and PC filters, and they were analysed, respectively, with micro-FTIR and micro-Raman spectroscopy and field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (FE-SEM-EDS). To facilitate the spectroscopic characterization of MPs, an innovative pre-treatment method was implemented that enabled the removal of particulate matter from the environment and the isolation of the MPs. As a result of this filter cleaning step, micro-FTIR and micro-Raman analyses allowed the polymers identification (e.g., polyethylene terephthalate (PET), polypropylene (PP) and polyethylene (PE)), as well as the detection of certain pigments (e.g., diarylide yellow, pigment blue 15 and red pigment oxo(oxoferriooxy)iron). Additionally, the morphological characteristics obtained through FE-SEM-EDS analyses are consistent with those typical of MPs. The BRIC ID-14 CELLOPHAN project, cofounded by INAIL, is kindly acknowledge for the financial support. Li, X., Shen, X., Jiang, W., Xi, Y. and Li, S. (2024) Ecotoxicol. Environ. Saf. 278, 116420. Kacprzak, S. and Tijing, L. D. (2022) J. Environ. Chem. Eng. 10, 107359. Ouyang, Z., Mao, R., Hu, E., Xiao, C., Yang, C. and Guo, X. (2022) Gondwana Research 108, 193-199.