Microplastics falling from the sky as snow in Arctic
August 14, 2019
Microplastics are entering the atmosphere and being carried vast distances to some of the remotest places on the planet, scientists said.
Researchers from Germany and Switzerland said in a study published Wednesday that they found evidence of "high concentrations" of microplastics are falling from the sky with snow in the Arctic and Bavarian and Swiss Alps.
"It's readily apparent that the majority of the microplastic in the snow comes from the air," said co-author Melanie Bergmann.
Another co-author, Gunnar Gerdts, said that snow is efficient in "washing" microplastics out of the air.
The finding that microscopic plastic are entering the air raises questions about whether humans and wildlife are inhaling the particles.
What are microplastics?
Microplastics are defined as particles of plastic less than 5mm in size. Around 150 million tons of plastic litter has entered rivers and oceans worldwide, where it is then broken down into smaller and smaller pieces by waves and UV radiation.
Microplastics can be found in seawater, marine sediment and the organisms that digest it.
Read more: Here, there, and in the toilet? Microplastics now found in our poop
What did the study find?
Researchers found 14,400 particles per liter in the Arctic. The highest concentration — 154,000 particles per liter — was found near a rural road in Bavaria.
The type of plastic varied by sample location. Most of the plastic was composed of varnish, rubber, polyethylene, and polyamide.
Read more: Plastic fibers pervasive in tap water worldwide, new study shows
How is the plastic reaching remote areas?
Researchers suggested that microplastics are sucked into the atmosphere and carried by winds.
This hypothesis is based on other studies that have shown grains of pollen — which are about the size of some plastic particles — are carried from middle latitudes to the Arctic. Similar studies have showed dust from the Sahara desert can travel more than 3,500 kilometers (1,550 miles) through the atmosphere.
Read more: Emissions and microplastics: How food waste hurts the environment
How was the study conducted?
Previous studies have found microplastics in the sky in the French Pyrenees, Tehran and near urban centers in France and China.
However, the German-Swiss study found microplastic concentrations much higher than those of other research.
The other studies sorted microplastic by hand under the microscope, leading to the possibility that some particles were missed.
The German-Swiss study used an infrared microscope which allowed researchers to identify the type of plastic and detect particles as small as 11 micrometers in size. This may account for the high particle concentrations discovered.
The study was conducted at sites on the North Sea island of Heligoland as well as in the Arctic, northern Germany and the Bavarian and Swiss Alps.