Shape Matters

Autor(en)
Daria Tatsii, Silvia Bucci, Taraprasad Bhowmick, Johannes Guettler, Lucie Bakels, Gholamhossein Bagheri, Andreas Stohl
Abstrakt

The deposition of airborne microplastic particles, including those exceeding 1000 μm in the longest dimension, has been observed in the most remote places on earth. However, their deposition patterns are difficult to reproduce using current atmospheric transport models. These models usually treat particles as perfect spheres, whereas the real shapes of microplastic particles are often far from spherical. Such particles experience lower settling velocities compared to volume equivalent spheres, leading to longer atmospheric transport. Here, we present novel laboratory experiments on the gravitational settling of microplastic fibers in air and find that their settling velocities are reduced by up to 76% compared to those of the spheres of the same volume. An atmospheric transport model constrained with the experimental data shows that shape-corrected settling velocities significantly increase the horizontal and vertical transport of particles. Our model results show that microplastic fibers of about 1 mm length emitted in populated areas are more likely to reach extremely remote regions of the globe, including the high Arctic, which is not the case for spheres of equivalent volume. We also calculate that fibers with lengths of up to 100 μm settle slowly enough to be lifted high into the stratosphere, where degradation by ultraviolet radiation may release chlorine and bromine, thus potentially damaging the stratospheric ozone layer. These findings suggest that the growing environmental burden and still increasing emissions of plastic pose multiple threats to life on earth.

Organisation(en)
Institut für Meteorologie und Geophysik
Externe Organisation(en)
Max-Planck-Institut für Plasmaphysik, Max-Planck-Institut für Dynamik und Selbstorganisation, Georg-August-Universität Göttingen
Journal
Environmental Science & Technology
Band
58
Seiten
671-682
Anzahl der Seiten
12
ISSN
0013-936X
DOI
https://doi.org/10.1021/acs.est.3c08209
Publikationsdatum
2023
Peer-reviewed
Ja
ÖFOS 2012
105206 Meteorologie
Schlagwörter
ASJC Scopus Sachgebiete
Allgemeine Chemie, Environmental Chemistry
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/6b0ec7c8-0af4-448f-b104-823331aa41a3