Current State of Microplastic Studies in Arctic and Antarctic Marine Sediments: A Critical Literature Review

As marine sediments act as temporary or permanent sinks for MPs, looking at MP distribution in this environmental matrix can help elucidate trends, as well as provide evidence for source appointment for this emerging contaminant in polar regions. Therefore, this review aims to summarize the available literature on microplastic (MP) in marine polar sediments, critically evaluate the methods used, and provide recommendations for future work. A total of 41 papers, filtered for the scope of this review, were assessed, analyzed by 10 criteria related to the quality control and quality assessment (QC/QA) of the works, assigning scores based on the rigor of the methodologies. Later, information regarding MP abundance, and distribution was extracted from 37 papers: the highest MP concentrations (239 – 13331 MP/kg) are reported for deep-sea sediments from the Arctic, while in Antarctica, where bays and beaches were more studied, the lowest concentrations are observed (0 – 0.009 MP/kg). Hydrodynamic patterns, sea-ice interactions, and the biological pump are the primary mechanisms responsible for the transport and accumulation of MP in polar marine sediments.