That’s why Dr. Lauren Biermann, a Lecturer in Marine Science at the University of Plymouth, recently led a pioneering study. It found a concerning link between sewage discharges and microplastics in the air. This study focused specifically on Plymouth Sound in the UK. It looked at two years of combined sewer overflow (CSO) records, as well as meteorological and satellite data. The findings suggest that coastal spills and specific wind conditions could contribute to the dispersion of microplastics into urban environments.
Those data revealed 178 days of sewage spills in just two years. These spills occurred during onshore winds of at least 6.5 m/s (approx. 23.4 km/h). The contamination from this wind blows directly towards the town of Plymouth. This should raise immediate red flags regarding the health impacts of living in such a community. Our research underscores the critical need for cities to address sewage overflow and mismanagement. This is especially true for communities with combined sewer systems, which suffer the greatest impacts.
Understanding the Research Methodology
Dr. Biermann’s study used a meticulous method by reviewing available data on CSOs into Plymouth Sound. To effectively link wind patterns with sewage discharges, the researchers were able to use same-day and long-term meteorological data. This novel approach enabled them to discover the exact conditions responsible for aerosolizing microplastics, moving them from oceanic ecosystems into urban environments.
Alongside researchers at Plymouth Marine Laboratory, including Dr. David Moffat, Artificial Intelligence and Data Scientist Lead, and University of Plymouth Professor of Big Data and Spatial Science Clive Sabel, the two worked to bolster the study. Their expertise went a long way in making it robust. Their collective efforts aimed to understand the environmental factors that facilitate the movement of microplastics from the sea into the atmosphere.
The study results indicated that microplastics and sewage-crested nanoplastics could be removed from the ocean’s surface. Such an unusual happening took place during almost 1,600 hours or 9.9% of the total period observed. This extended timespan is significant, as it indicates that this phenomenon is not merely the result of chance. Instead, it’s probably more representative of a methodical process defined by the elements.
Implications for Public Health
This research does more than look at environmental concerns. It underscores alarming human health threats associated with inhaling and ingesting microplastics. Dr. Biermann highlighted the numerous studies that have found high concentrations of these toxic particles in sewage discharges. This poses serious questions about their long-term impacts on generalized public health. Gale-force winds enhance the ability of microplastics to escape the ocean. This doubles the risks for city-dwellers—especially those majority urban populations who live on or near coasts.
Thousands of cities in the UK and around the world continue to use combined sewer systems. The results of this small study call for a reconsideration of waste management practices and their health impacts. The researchers stress that these risks must be taken into account. Urban planners and policymakers should directly consider them when designing and deploying infrastructure interventions.
Beyond estimating acute health hazards, the study opened avenues for research on where airborne microplastics may come from. As urban landscapes grow and climate impacts shift the frequency and intensity of rainfall, we need to know how these contaminants travel. Yet, this knowledge is critical to protecting public health.
Future Research Directions
The study published in Scientific Reports discusses potential directions for future research. Another aim is to reduce the impacts of airborne microplastics. However, researchers are calling for larger, more advanced studies. Their goal is to better understand the direct connection between sewage spills, coastal winds, and airborne microplastics in U.S. cities.
Future research will be more focused on practical strategies cities can implement. These approaches are likely to reduce microplastic outputs linked to the sewage treatment works. Marine scientists, public health experts, and urban planners need to work across disciplines. Working together, they have the potential to create cutting-edge ideas to address this urgent challenge.