Macroplastics contamination on glaciers from Italian Central-Western Alps

Plastics are synthetic organic polymers playing an irreplaceable role in our everyday life. However, their massive use, improper management and end-life disposal cause plastic accumulation in the environment. Plastic contamination is ubiquitous in aquatic and terrestrial ecosystems, including mountain remote areas. The present work aimed at investigating the presence of macroplastics on five glaciers of the Italian Central-Western Alps, namely Cedec and Forni glaciers (Ortles-Cevedale group) and Indren, Lys and Verra glaciers (Monte Rosa group). In late spring-summer of 2020, macroplastics were collected along normal access paths leading to some peaks of these mountain groups. In laboratory, macroplastics were sorted according to their weight, size, color, origin, usage section and polymeric composition. Macroplastics were found along all the paths, with a mean (± standard error) abundance of 18.9 ± 5.1 items per transect and an abundance per linear km ranging between 2.4 and 26.4 items/km. No significant differences of macroplastic abundance occurred between the mountain groups. Polyolefin, such as polyethylene, polystyrene and polypropylene, were the most frequent polymers contaminating glaciers, accounting for the 31% of the fingerprint, followed by polyethylene terephthalate (12%) and polyurethane (8%). The origin of most macroplastics was attributable to food packaging and items deriving from the wear of mountaineering equipment and/or clothing, which reached glacier paths through deliberate or involuntary abandonment. Virtuous behaviors aimed at limiting the abandonment of plastic waste or at collecting the items encountered on the paths should be encouraged to reduce the amount of macroplastics in remote areas.