Environmental pollution from microplastic (i.e. plastic pieces from 1 μm to 5 mm) in marine and limnic water systems has become an increasingly important focus of scientific research within the last few years. It is estimated that 86 million tonnes of plastic are in the world’s oceans, and around 10 million tonnes are added annually. However, only incomplete studies have been carried out for Switzerland’s surface waters, and for the Engadine such research is non-existent, possibly also because this region still seems to be unaffected and pristine. The objective of this study was to find out whether microplastic particles can be found in the Upper Engadine, by sampling at 8 different measuring locations with different distances to the source of the river Inn at Lake Lunghin, different population densities, as well as different types of usage, for example for events or sport-activities.
For sampling, a wooden self-constructed LADI-trawl was built. The aim was to have a low-cost, light and easily transportable construction. 60 representative fragments were analysed by means of FT-IR spectroscopy, of which 51 were assigned to 22 different types of plastics. Larger particles, so-called microplastic, were found at 2 locations. Thus, plastic residues were detected at all measuring sites, which shows that even seemingly remote regions and sparsely populated areas are affected by the pollution of microplastic. The findings of this research are of key importance for alpine regions, as evidence of plastic was found at over 2400 meters above sea level near the source of the river Inn, a remote location in a major European watershed.