We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Long-distance atmospheric transport of microplastic fibers depends on their shapes
Summary
This study investigated how the shape of microplastic fibers affects how far they travel through the atmosphere. Long, thin fibers stay airborne longer and can be transported greater distances than compact fragments, explaining why synthetic textile fibers are so widely found in remote environments.
Recent studies have highlighted the importance of the atmosphere in the long-range transport of microplastic fibers (MPFs). However, both dry deposition processes and sources of MPFs are poorly understood due to their complexity in size and shape, which can be 100s $\mu m$ long, possessing round or flat cross-sections with dimensions of $O(1)\,\mu m$ thickness, and $O(10)\,\mu m$ width. Here, we develop a theory-based settling velocity model for MPFs in the atmosphere, predicting a much smaller aerodynamic size than a volumetrically equivalent spherical particle. Incorrect identification of flat fibers as cylindrical ones due to uncertainty in the thickness of sampled MPFs overestimates their dry deposition rate. Accounting for fiber thickness in sampled MPFs leads to a mean residence-time enhancement above $450\%$ compared to spherical-shaped particles, suggesting a much more efficient long-range transport of flat fibers than previously thought and that the ocean might be a major source of atmospheric plastics.