How tiny plastic particles enter the atmosphere is an important question, as airborne microplastics are a potential health threat. Using a global chemical transport model, researchers have provided evidence that, contrary to previous claims, the ocean is not a major source of microplastics to the atmosphere, but a significant sink.

Plastic dust is polluting the global environment: Microplastics—particles less than 5 mm in diameter—have been detected not only in soils, freshwater, and the ocean, but also in the air that we breathe. This could pose a threat to human health, as the smallest particles in particular can enter the respiratory system and the bloodstream.

The study also shows how size determines the transport of microplastics in the atmosphere: larger particles settle relatively quickly, either still on land or near the coastlines. Small microplastic particles can remain in the atmosphere for up to one year, facilitating their transport around the globe.

Source:

Global atmospheric distribution of microplastics with evidence of low oceanic emissions

https://www.nature.com/articles/s41612-025-00914-3