Electric forces can enhance the emission of microplastics into air

Microplastics (MPs) are problematic pollutants in various environmental contexts. Dust storms, blowing dusts, and dust devils can detach significant amounts of surface MPs into the atmosphere and migrate them far from their original sources via atmospheric transport. Studies have shown that strong electrostatic fields that exceed 150 kV/m can be observed during dust storm events. In this study, we perform theoretical calculations and laboratory experiments that demonstrate that MPs can be directly lifted under a strong electric field, and the threshold electric field (Ee) required for the lifting of MPs is closely related to the material composition and morphology of the MPs themselves and the air humidity. The electric forces generated by these electric fields can decrease the threshold friction velocity required to initiate the lifting of MPs. Specifically, electric fields exceeding 200 kV/m can directly lift surface particles, while fields above 120 kV/m significantly reduce the threshold friction velocity required for wind-driven particle movement by 10 %. These effects are most pronounced for particles with diameters ranging from 80 to 250 μm. We concluded that electric forces enhance MPs lifting, playing a key role in their motion at the particle scale and atmospheric transport at the regional scale. The enhanced loading of MPs into the atmosphere increases their transport distance, This long-range transport not only exacerbates global microplastic pollution but also leads to the deposition of MPs in remote ecosystems, such as polar regions, oceans, and mountainous areas, affecting local biodiversity. Meanwhile, humans may face potential health risks by inhaling or ingesting air, water, and food contaminated with MPs, such as inflammatory responses or the accumulation of harmful chemicals. Additionally, the distribution of MPs in the atmosphere may impact the climate system, for example, by altering cloud condensation nuclei formation, which in turn affects precipitation patterns and Earth's radiation balance.