At the summit of the Pic du Midi de Bigorre there are surprisingly large amounts of tiny plastic particles. This is what an international team reported in the magazine “Nature Communications”. The microplastic that was discovered in the French Pyrenees in southern France could have been transported 4550 kilometers, including across continents and oceans, it is said.
Pieces of plastic that are smaller than five millimeters are called microplastics. Some of them may therefore be difficult to see with the naked eye, but such substances have been shown to be widespread in the environment. They have already been found in rivers, oceans and snow. And now also around the summit of the Pic du Midi, which strengthens the thesis that microplastics can spread widely via the air.
The team around atmospheric researcher Steve Allen analyzed around 10,000 cubic meters of air, which was collected by a pump installed at the observatory on the Pic du Midi. Result: The concentration was 0.09 to 0.66 microplastic particles per cubic meter over four summer months at 2,877 meters above sea level. According to the researchers, this does not pose a direct threat, but the fact that the particles are located far away from sources of pollution is still surprising.
With the help of mathematical models, the scientists tried to trace the journey of the microplastic. According to this, the particles are likely to have come mainly from the west and south, across the Atlantic and the Mediterranean. This points to a “transcontinental and transoceanic transport through the free troposphere”, ie the layer of the atmosphere above the clouds.