The atmosphere serves as a transport medium for microplastics, distributing them globally and potentially posing health risks through inhalation for humans and animals, as well as contaminating oceans and soils upon settling. A recent study by the Department of Meteorology and Geophysics at the University of Vienna, published in Nature, estimates global microplastic emissions from land-based and oceanic sources into the atmosphere.
Study Methodology
Researchers Ioanna Evangelou, Silvia Bucci, and Andreas Stohl compiled 2,782 global measurements of atmospheric microplastics from existing literature. They compared these measurements with simulations from a transport model that incorporated three different published emission estimates.
Key Findings
The comparison revealed that the model significantly overestimated the number of microplastic particles in the atmosphere and their deposition. By analyzing this discrepancy, the researchers were able to rescale emission estimates separately for land and ocean sources.
Revised estimates indicate that over 20 times more microplastic particles are emitted from land-based sources than from the ocean. However, the study also clarified that the total emitted mass of microplastics is higher over the ocean than over land, attributed to the larger average size of oceanic particles.
Future Research
The scientists emphasized the need for more comprehensive measurements to reduce uncertainties in microplastic pollution estimates and global transport models. Specific areas requiring further data include the contribution of sources like traffic and accurate determination of the size distribution of microplastic particles.