First evidence of airborne microplastics in the sub-Antarctic Beagle Channel: Detection and characterization by infrared and Raman microspectroscopies

Microplastic pollution is increasingly recognized as a global environmental issue; however, atmospheric microplastic circulation remains poorly studied in sub-Antarctic regions, especially in southern South America. This study presents the first evidence of airborne microplastics in the sub-Antarctic Beagle Channel, based on passive sampling conducted on Isla Redonda, an uninhabited island near Ushuaia, Argentina. Passive samplers were employed over an 18-month period, allowing for continuous collection of atmospheric particles. Suspected anthropogenic particles were analyzed using FTIR and Raman microspectroscopies to determine polymer composition and associated additives. Fibers were the dominant particle type, accounting for over 80 % of the total. Semi-synthetic cotton, polyamide, polyester, and polyethylene were the most identified polymers. Raman analysis further revealed the presence of industrial pigments, including indigo, on both synthetic and semi-synthetic fibers. The predominance of textile-related polymers and dyes suggests a strong influence of long-range atmospheric transport, likely from southern South America, as well as potential local contributions from the nearby city of Ushuaia. These findings, along with the use of passive samplers, establish a crucial baseline for future atmospheric microplastic monitoring in high-latitude regions and underscore the strategic importance of including sub-Antarctic areas in global efforts to understand the dispersion pathways and environmental impacts of airborne microplastics.