Plastics blowing their way to the Pyrenees Mountains

Typical cliffs in the Pyrenees Mountain Range.

Close your eyes and imagine a pristine region of a mountain range with snow-capped peaks, glacier fields, precipitous cliffs, dense forests, and rolling hills blanketed in beautiful flora. In your vision of this pristine region, are humans a part of the natural environment or are they a separate entity? Perhaps this mountain range is the Pyrenees Mountain Range, extending almost 500 kilometers from the Bay of Biscay on the Atlantic Ocean to the shores of the Mediterranean Sea, forming a natural border between Spain and France with the microstate of Andorra sandwiched in the middle. The highest peak, Aneto, stretches 3,404 meters into the sky at the center of the range and small towns are scattered throughout the lower elevation areas. Parts of the Pyrenees Mountains are untouched by humans – until recently that is. Microplastics were found during a study at the Bernadouze meteorological station in a remote area of the range.

Microplastics found during a Florida Sea Grant water sampling in a freshwater Florida stream.

In the new study* published in Nature Geoscience, a team of French and Scottish researchers found that plastic particles may be traveling incredibly far distances through the atmosphere. For five months during the winter season researchers analyzed dust, rain, and snow and found that an average of 365 plastic particles, ranging in size from ~750 µm long to microplastic fragments ≤300 µm, had precipitated per square meter. That’s approximately 11,400 plastic particles within one square meter per month.  The samples included various types of plastics, including fragments of plastic bags, packing materials, and cloth fibers. The researchers conducted this study in a largely unpopulated area, with the nearest village, Vicdessos, 6 km away with a population less than 600 people. The nearest city, Toulouse, is 120 kilometers away. Finding this much plastic debris in a mostly uninhabited area was quite the shock.

Marine debris washed up on a beach in Semporna, Malaysia after a tide retreated. (Photo by Marlena Skrobe)

Microplastics have been found in rivers, oceans, the soil, and even in the bodies of organisms – including humans. Previous research has found these microplastics are in the air around larger cities, like Dongguan city in China, but never before has a study been done on the atmospheric fallout in such a remote location.  While the exact distance that these microplastics traveled to get to the Bernadouze meteorological station is unknown and more in depth transport modelling may illuminate the exact source location, the sampling suggested that the sources of these microplastics are at least over 100 kilometers away.  So what are the implications of microplastics traveling long distances through the atmosphere?

Plastic debris are more than just an unsightly problem. Plastic is the most prevalent type of marine litter found in our oceans. Most plastic in the ocean actually comes from land-based activities, but eventually makes its way to the oceans from intentional or unintentional dumping. Larger sized plastics in the marine environment have garnered much attention in the media, like when a dead sperm whale washed ashore on the island of Sardinia, Italy, with 48 pounds of plastic in its stomach. But microplastics are also harmful to organisms and are even harder to monitor due to their extremely small size.

Microplastics found in the Patapsco River, Maryland during a National Oceanic and Atmospheric Association Marine Debris Program manta trawl.

Microplastics come from a variety of sources, but usually come from larger plastic debris that eventually degrades into smaller and smaller pieces, since plastic items can take up to a thousand years to decompose. Studies have shown that microplastics may cause reproductive issues in a variety of marine mollusks. Microplastics may even alter the chemical composition of the environment.  And while their exact effects on human life is poorly understood, researchers are becoming increasingly certain that microplastics a ubiquitous part of human life. They are in our facial cleansers and soaps. We use microbeads, a type of microplastic, as an exfoliant in various health products, like toothpastes and cleansers. These pieces of plastic are so tiny that they pass through various types of water filtrations and end up in lakes, rivers, and our oceans. And they could now be airborne in areas far removed from human activity.

If microplastics are emerging atop a mostly uninhabited area of the Pyrenees mountains, where else could they be? According to the the Food and Agriculture Organization of the United Nations (FAO), plastic production reached a whopping 322 million tonnes in 2015, with an additional 61 million tonnes coming from the production of synthetic fibers. The FAO reports that the production of plastic will likely continue to increase and even double by 2025. Since microplastics  are difficult to monitor and to get rid of, how should we tackle this pervasive problem? Perhaps the only viable option is to produce less plastic – stop the problem at its source. This may be one of the biggest challenges of our lifetime, but hopefully as more research is performed we will have a better understanding of how to approach this immense problem. Or perhaps it may start with one decision – your decision – to not use plastic.


*In the interest of sharing scientific knowledge, we do our best to cite sources that are free and available for all of our readers. However, sometimes we cannot avoid citing articles that restrict access with a paywall. If you are interested in learning more about a specific source, please reach out to kmartin8@uw.edu.