Microplastics and nanoplastics released from a PPE mask under a simulated bushfire condition

Due to COVID-19, large amounts of personal protective equipment (PPE) have been used, and many PPE units are made of plastics, such as face masks. The masks can be burned naturally in a bushfire or artificially at the incineration plants, and release microplastics and nanoplastics from the mask plastic fibres. A fire can cause the plastic, such as polypropylene (PP) fibres, to be molten and stick to the solid surface, such as glass, soil, concrete or plant, as films or islands, due to the binding property of the molten plastic material. Once the films or islands are peeled off in the processes such as weathering, ageing, or treatment and clean-up, there are residuals leftover, which are identified as nanoplastics and microplastics via Raman imaging, with the significant release amount of similar to 1100 nanoplastics / 10 mu m(2) or similar to 11 billion / cm(2), and similar to 50 microplastics / 420 mu m(2) or similar to 12 million / cm(2). Moreover, surface group is deviated on the plastic surface, which can also be distinguished and visualised as well via Raman imaging, down to nano size. This test validates the Raman imaging approach to capture microplastics and nanoplastics, and also provides important information about the fate and transportation of PPE mask in the environment, particularly when subjected to a fire. Overall, Raman imaging can be an effective option to characterise the microplastics and nanoplastics, along with the deviated surface group.

Automated summary

Due to the COVID-19 pandemic, a large amount of personal protective equipment (PPE), including plastic face masks, has been used. When these masks are burned naturally or artificially, microplastics and nanoplastics are released from the plastic fibers. A Raman imaging test confirms the presence of nanoplastics and microplastics on the surface of the masks, as well as deviations in surface groups. This research provides valuable information about the fate and transportation of PPE masks in the environment, especially in the event of a fire.