Researchers in Germany and Switzerland have found microplastic in snow in the Alps and the Arctic. The minute particles are transported by the atmosphere and washed out of the air, especially by snow.
Microplastic particles can travel over tremendous distances in the atmosphere, landing in remote regions such as the Alps and the Arctic, according to a team of experts from the Alfred Wegener Institute / Helmholtz Centre for Polar and Marine Research (AWI) and the Swiss WSL Institute for Snow and Avalanche Research (SLF).
The researchers analysed snow samples from Helgoland, Bavaria and Bremen in Germany, the Swiss Alps and the Arctic, all of which contained high concentrations of microplastic – even in remote places such as in snow on drifting ice floes.
“It’s readily apparent that the majority of the microplastic in the snow comes from the air,” said Melanie Bergmann, who led the team. Similar research conducted on grains of pollen, which are roughly the same size as the microplastic particles, show that they are transported by air to the Arctic. Likewise, dust from the Sahara can cover distances of 3,500 kilometres or more to reach the northeast Atlantic.
The researchers found the highest concentration of microplastic – 154,000 particles per litre – in samples gathered near a rural road in Bavaria, but even snow in the Arctic contained up to 14,400 particles per litre. The researchers found that the types of plastic varied greatly between sampling sites: near the rural road in Bavaria, the samples contained various types of rubber, such as those used in car tires, while those in the Arctic, had nitrile rubber, acrylates and paint.
One surprising part of the study is that the microplastic concentrations found are considerably higher than those in studies conducted by other researchers on other materials, such as dust deposits.
Study co-leader Gunnar Gerdts ascribes this to two aspects: “First of all, snow is extremely efficient when it comes to washing microplastic out of the atmosphere. Secondly, it could be due to the infrared spectroscopy we used, which allowed us to detect even the smallest particles – down to a size of only 11 micrometre.”
While is by now well established that our oceans are full of microplastic and that animals and humans absorb microplastic from what they eat, this latest study raises another risk. “Once we’ve determined that large quantities of microplastic can also be transported by the air, it naturally raises the question as to whether and how much plastic we’re inhaling,” warns Bergmann.
Image credit: AWI