Within just a few decades, humans have managed to spread plastic to almost every corner of the planet, from human poop and sea turtle bellies to Rocky Mountain rainwater and the Mariana Trench.

In a new milestone of Earthling's desperate addiction to plastic, thousands of microplastic particles have been discovered in the Arctic and other remote chilly environments in the Northern Hemisphere.

Reporting this week in the journal Science Advances, scientists at the Alfred Wegener Institute in Germany set out to document this phenomenon and understand how the microplastics were being transported over tremendous distances.

Tiny plastic fibers were found across two dozen locations in the Northern Hemisphere, including remote Arctic ice floes, the remote Norwegian archipelago of Svalbard, and the Swiss Alps. The snow in the Arctic – often considered one of the world's last pristine environments – contained up to 14,400 particles per liter, while snow in parts of rural Bavaria in mainland Europe contained up to 154,000 particles per liter. 

They measured the quantity of microplastics in the area’s snow by pouring meltwater through a filter and analyzing the residue with an infrared microscope. The microplastic ranged in size from 11 micrometers to 5 millimeters and mainly consisted of multi-colored flecks of rubber, varnishes, and other forms of plastic.

The team revealed that microscopic particles of plastic were also falling out of the sky with snow. Just like plant pollen, which can also be transported from the middle latitudes to the Arctic, the microplastics are swept up into the air, pulled along currents, and then dumped back to Earth through rain or snow.

Defined as any plastic fragments less than 5 millimeters in length, microplastics are known to come from a number of sources, including rubber tires, paint, cosmetics, toothpaste, and synthetic clothing. However, the researcher says it's not possible to identify the source of these microplastics at the current time. While the full consequences of this problem are as yet uncertain, the study raises some serious questions about the number of microplastics that are being inhaled by humans and wildlife.

"To date, there are virtually no studies investigating the extent to which human beings are subject to microplastic contamination," lead study author Dr Melanie Bergmann said in a statement.

"But 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. Older findings from medical research offer promising points of departure for work in this direction."