When the Wind Blows Plastic: How Coastal Sewer Overflows May Be Sending Microplastics into the Air

We’ve long known that microplastics and nanoplastics contaminate our oceans, rivers, and soils. However, a new study suggests they may also be riding the wind, escaping from combined sewer overflows (CSOs) along the coast and becoming part of our atmosphere.

Published in 2025, this research models how wind speed, turbulence, and environmental conditions can aerosolise plastics from wastewater outflows, potentially making them an airborne pollutant we can breathe in.

How Microplastics Become Airborne

Combined sewer overflows discharge a mix of stormwater and untreated sewage during heavy rainfall. In coastal areas, these flows often contain:

Fibres from textiles
Fragments from packaging
Particles from degraded plastics

The study proposes that wave action and wind shear at the water’s surface can break up plastic-laden droplets, lifting micro- and nanoplastics into the atmosphere.

Key Findings from the Study

Wind speed is a critical factor: Higher winds greatly increase aerosolisation potential.
Droplet size distribution influences how far particles can travel.
Nanoplastics may remain airborne for longer periods, thereby increasing inhalation risks.
Urban coastal environments with frequent CSO events are hotspots for possible airborne plastic emissions.

The model predicts that aerosolised plastics could travel inland, contaminating air, soil, and even food crops.

Why This Matters

Airborne microplastics and nanoplastics:

Can penetrate deep into the lungs when inhaled
May carry toxic additives or adsorbed pollutants
Contribute to plastic cycling between land, water, and air
Pose risks for both human health and ecosystems

This study adds a new atmospheric pathway to the global plastic pollution narrative, suggesting we’re not just eating and drinking plastics, we may be breathing them too.

Potential Solutions

Upgrading sewer infrastructure to reduce CSO events
Stormwater filtration at outflow points
Windbreaks and surface covers for vulnerable CSO discharge zones
Reducing plastic waste at the source to limit inputs into wastewater

Conclusion

This research is a wake-up call: plastic pollution isn’t just a land and sea problem—it’s taking to the skies. Understanding and addressing wind-driven microplastic aerosolisation could be key to protecting both environmental and public health.

Reference

Biermann, L., Moffat, D., Sabel, C. E., & Stovin, T. E. (2025). The theoretical role of the wind in aerosolising microplastics and nanoplastics from coastal combined sewer overflows. Scientific Reports, 15(1), 23623. https://doi.org/10.1038/s41598-025-06115-5