Microplastics from Africa or North America found in the Pyrenees

The microplastics of a few millimeters at most, resulting for example from deterioration of packaging or washing clothes, are of increasing concern to researchers. Their presence has even been highlighted near the summit of Everest, probably resulting from the equipment of climbers, more and more, who flock each year to the roof of the world. Other studies have found them in the snow of the Alps or the Arctic and they have also been identified in rivers and the most remote parts of the oceans. Studies have also measured it in theair close to the ground.

Scientists from the CNRS, the University of Grenoble Alpes 2 and the University of Strathclyde (Scotland) this time looked for them in “pure” air, at altitude above the clouds. Samples were taken at the Pic du Midi observatory, perched at 2,877 meters in the French Pyrenees, between June and October 2017, with a pump sucking 10,000 m3 of air per week.

All were found to contain microplastics. In quantities without immediate risk to health, but significant in a presumed preserved area, where “One cannot easily attribute” this pollution has no local origin, write the researchers.

“There is no possible storage well”

To understand its origin, they calculated the trajectory of the different air masses sampled over the 7 days preceding the samples. As a result, the pollutants originate in particular from the northwest of the African continent, passing over the Mediterranean, North America or the Atlantic Ocean.

These data confirm an intercontinental journey, because the atmospheric zone studied, the troposphere free, act like “A super-fast lane” over very large distances for particles, says Steve Allen, lead author of the study. For the researcher, it is the marine origin of a part of these particles which constitutes the most salient teaching of thestudy.

” That the plastic be taken from the ocean to such altitudes shows that there is no possible storage well, it turns in circles in a perpetual cycle. This shows that we cannot just send the plastic abroad, because it will come back to you ” in another form.

Especially since some of the particles analyzed, of the order of micron, “Are of a size that we can breathe”, adds Deonie Allen, also author of the study. These results “Show that it is indeed a global problem”, adds the researcher.