A Pilot Study of Potential Microplastic Particles in Arctic Plant Tissue Using SEM-EDS

Sammanfattning

Plastic pollution including micro- and nano plastics is a widespread environmental issue, also occurring in Arctic ecosystems. There is, however, limited research on microplastics in terrestrial ecosystems, especially in the Arctic despite it being shown in previous studies that microplastics can enter plant tissues in several different ways. The aim of this study was to investigate if there are any potential microplastics present in arctic plant tissues, using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and evaluate methodological limitations, as well as testing the suitability of digestion as a method for further analysis, using potassium hydroxide (KOH). The plant samples were collected from Lake Toolik in Alaska and included three plant species. The findings include some particles within the plant tissues showing a distinct morphological structure, similar to those of microplastics. One of the particles exhibited a strong chlorine signal, compared to the other particles observed. However, due to methodological limitations such as overlapping elements, background noise from surrounding plant tissues, and a relatively low image resolution, interpretation of the results remained cautious. The digestion using KOH was incomplete, and therefore no further analysis and polymer confirmation could be achieved. The findings suggest that SEM-EDS may be used as a preliminary method for analyzing microplastics in plant tissues, but that another spectroscopic method such as Raman spectroscopy is necessary for a reliable polymer identification.