Airborne microplastic concentrations in remote coastal environments

While plastics have been detected in remote locations across the planet, there remains uncertainty in the mechanisms governing global microplastic transport. The transfer of plastic pollution from the marine environment to the air via crashing waves may be a significant avenue of atmospheric microplastic entrainment. In this study, sampling was conducted at coastal locations in Aotearoa New Zealand, a remote region near the Southern Ocean that does not contain high levels of plastic production. Results from both active and passive sampling, in conjunction with air parcel back trajectory analysis, indicated that local atmospheric microplastic concentrations were derived from the marine environment. The use of pyrolysis GC/MS allowed for the determination of airborne mass concentrations of seven different polymers, finding that airborne microplastic levels at remote coastal areas were similar to those previously reported at urban sampling locations. These results highlight the significance of the air-ocean interface in relation to long range microplastic transport, and further work relating to the impacts on climate – such as in the Southern Ocean region – and to local health are warranted.