Plastic waste is a growing environmental problem due to its long lifetime. Microplastics, i.e., plastic fragments below 5 mm in size, can be produced by the degradation of larger particles or be introduced directly, e.g., in the form of polymer microfibers. Microplastics can have a negative effect on organisms, e.g., in the oceans, and carry organic pollutants. They can also become airborne and pollute remote regions.
Alex R. Aves, University of Canterbury, Christchurch, New Zealand, and colleagues have confirmed the presence of microplastics in Antarctic snow for the first time. The team collected snow samples from 19 sites in the Ross Island region of the Antarctic, some near research stations and some in more remote regions. The samples were thawed and filtered, and a wet peroxide oxidation digestion was used to remove organic material. Suspected microplastic particles were then identified under a microscope and characterized using infrared (IR) spectroscopy.
The team found microplastics in all 19 snow samples, with a total of 109 particles and an average concentration of ca. 29 particles L−1 of melted snow. Near research bases, the concentration was higher than in remote regions (ca. 47 particles L−1 vs. ca. 23 particles L−1). Polyethylene terephthalate (PET) was the most commonly found polymer, and fibers were the most common shape.
The researchers investigated possible sources of these microplastics. They ran air mass trajectories backward from the time of sampling and found that microplastic particles could have traveled up to 6000 km. In addition, the identified polymers were consistent with those used in clothing and equipment at the nearby research stations. Thus, according to the team, it is likely that local sources contributed to microplastic pollution.
- First evidence of microplastics in Antarctic snow,
Alex R. Aves, Laura E. Revell, Sally Gaw, Helena Ruffell, Alex Schuddeboom, Ngaire E. Wotherspoon, Michelle LaRue, Adrian J. McDonald,