Microplastics in the Atmosphere: A Global Perspective

Abstract Microplastic particles have been detected in various parts of the atmosphere. Earlier studies have attributed their primary source to the oceans. However, recent laboratory studies suggest that ocean emission fluxes are considerably lower than previously assumed, and specifically that they are lower than the sources related to transportation on land. Here, we perform model simulations of the atmospheric transport and deposition of microplastic particles at the global scale based on bottom-up reduced ocean emissions. We conclude that approximately 124 kilotons of microplastics are suspended in the atmosphere globally, and that 19 million tons/year are deposited on the Earth's surface with only 3 million tons/year being deposited to the oceans. The highest human exposure risk to microplastics is found in densely populated regions. The Arctic and Antarctica are significant receptor regions for microplastic particles with a diameter smaller than 1.5 µm that are transported over long distances.