Environment: Long-distance movement of microplastics

Microplastics, detected in southern France, could have been transported over 4,500 km from their source, including over continents and oceans, suggests a study published in Nature Communications. The findings suggest that microplastic pollution can spread globally from its sources to remote regions.

Plastic pollution has been documented at high elevations and latitudes, and in regions with little local plastic use. The transportation of microplastics through the atmosphere has been suggested as occurring on regional scales. However, it is unclear how widespread this phenomenon is and, if like mercury and other pollutants, there is free transport of microplastics through the atmosphere that enables trans-continental movement.

Steve Allen and colleagues collected atmospheric microplastics at the high-elevation Pic du Midi Observatory in the French Pyrenees, southern France, and used atmospheric transport modelling to understand the potential sources and paths of these particles. Air masses containing microplastic' particles were found to have moved around 4,550 km on average in the week before arriving at the observatory, and were projected to mainly have arrived from the west and south, over the Atlantic Ocean and Mediterranean Sea. The authors suggest that the potential sources of the microplastics may include North America, western Europe and North Africa, indicating trans-continental and trans-oceanic transport through the free troposphere (the layer of atmosphere above the clouds).

The findings suggest that regions with little local plastic usage could be impacted by microplastic source regions located far away.