A team of experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) has now found that microplastic particles can apparently be transported over tremendous distances by the atmosphere and are later washed out of the air by precipitation, particularly snow. As the team led by Dr Melanie Bergmann and Dr Gunnar Gerdts report in the journal Science Advances, the analyses they conducted on snow samples from Helgoland, Bavaria, Bremen, the Swiss Alps and the Arctic confirm that the snow at all sites contained high concentrations of microplastic – even in remote reaches of the Arctic, on the island Svalbard, and in snow on drifting ice floes. “It’s readily apparent that the majority of the microplastic in the snow comes from the air,” says Melanie Bergmann. Her hypothesis is supported by past research conducted on grains of pollen, in which experts confirmed that pollen from the middle latitudes is transported by the air to the Arctic. These grains are roughly the same size as the microplastic particles; similarly, dust from the Sahara can cover distances of 3,500 km or more, reaching the northeast Atlantic.
The AWI researchers found the highest concentration in samples gathered near a rural road in Bavaria – 154,000 particles per litre. Even the snow in the Arctic contained up to 14,400 particles per litre. The types of plastic found also varied greatly between sampling sites: in the Arctic, the researchers chiefly found nitrile rubber, acrylates and paint, which are used in a host of applications. Given its resistance to various types of fuel and broad temperature range, nitrile rubber is often used in gaskets and hoses. Paints containing plastic are used in several different areas, e.g. to coat the surfaces of buildings, ships, cars and offshore oil rigs. Near the rural road in Bavaria, the samples especially contained various types of rubber, which is used in countless applications, such as automotive tyres.