A scientific study collected samples over a five-month period from a secluded area of the mountains, which form a natural border between France and Spain.
The research paper Atmospheric transport and deposition of microplastics in a remote mountain catchment published in the Nature Geoscience research journal, reveals that samples from two separate monitoring devices were analysed to identify whether the tiny plastic pieces, invisible to the naked eye and less than five millimetres long, were present in the largely inaccessible mountain area.
Despite the remote location, researchers recorded average daily counts of 365 deposits per square metre of the pervasive material.
It isn’t yet known the extent of the distance that microplastics can travel, but the research also reveals that the analysis of air trajectory shows fragments are travelling through the atmosphere over distances of at least almost 60 miles.
Joint lead researcher Steve Allen, a researcher at EcoLab, Toulouse and a PhD student from the University of Strathclyde, said: “It’s astounding and worrying that so many particles were found in the Pyrenees field site.
“What we can unequivocally prove is that it’s being transported there by the wind.
“It opens up the possibility that it’s not only in the cities are you breathing this in, but it can travel quite some distance from the sources.
“Plastic litter is an increasing global issue and one of the key environmental challenges we face on global scale.”
Co-author Dr Deonie Allen of EcoLab said: “The drivers in plastic degradation are fairly well known, but the transport drivers and mechanisms – especially atmospheric transport – for microplastic appears to be complex and an area of research that now needs to be unravelled.”
The team, a collaboration between the University of Strathclyde and the French National Research Centre at the University of Toulouse, collected samples from the field site in south west France from an ‘uncontaminated’ area just over four miles away from the nearest village and around 75 miles from the nearest city of Toulouse.
The area is considered to be pristine, untouched wilderness due to a lack of development, its inaccessibility and distance from major cities and industrial centres.
Dr Gael Le Roux from EcoLab said: “This mountainous area has been the subject of numerous interdisciplinary studies in ecology and environment over the past decade but we would still never have anticipated that this latest study would reveal such high levels of microplastics deposits.”
Local rain, wind speed and snow fall was also recorded during the winter period of 2017 to 2018.
Steve Allen said: “The meteorological station there has two existing deposition collectors, which supplied us with the samples. We measured it over a five-month period during the winter which was significant as the Pyrenees are generally covered in snow and the ground is damp.
“This is likely to make it harder for plastic dust to be lifted up into the air which raises the question of how far it had come from.”
Microplastics, which are completely invisible to the naked eye, can be harmful to oceans and aquatic life.
They have been found in tap water around the world and in some of the most remote places on earth, with studies showing they have even reached Antarctica.
As well as the physical fragments, toxins added during manufacturing and organic pollutants gathered during air and water travel also accumulate in ecosystems.
Steve Allen said: “We don’t know if they are harmful, but there have been studies on mice and fish in lab conditions with virgin laboratory grown plastic which have shown the effects of digesting or breathing in microplastics can lead to changes in behaviour in things like feeding and mating habits.
“We don’t know how much of a difference there is between this lab grown plastic and the microplastics in the environment which can pick up things like pesticides, but we do know we need to stop the plastic going into the environment and we need to stop our use of it.”
The French National Research Agency, the Agence Nationale de la Recherche, funded the research through Ecolab, Campus ENSAT and the Marie Curie Prestige Fellowship.