A new study by the University of Portsmouth shows that plastic items make up more than seven in ten pieces of litter recorded across the UK, with countryside locations and public recreation areas carrying some of the heaviest burdens.
The research draws on ten years of citizen science data collected between 2015 and 2024, using artificial intelligence to bring together information from thousands of volunteers who logged litter through mobile apps, beach clean surveys and community projects. This has created one of the most comprehensive national overviews of litter pollution ever produced in the UK.
More than 460,000 individual litter records were analysed and standardised, allowing researchers to compare data that was previously fragmented or incompatible. By combining these records with detailed information on land use and local infrastructure, researchers identified where litter is accumulating, and which settings are most affected.
What people are reporting on the ground is now unmistakable in the data. Plastics dominate the litter landscape, and some of the most affected places are not just city centres, but more rural and recreational environments that people associate with nature and escape.
Dr Keiron Roberts, Revolution Plastics Institute at the University of Portsmouth
Recreation and outdoor spaces recorded some of the highest litter densities within the datasets, followed by transport areas, accommodation sites and food and drink locations. The findings also show that rural and low-density areas are disproportionately affected, challenging the widespread perception that litter is mainly an urban problem.
Dr Keiron Roberts , from the Revolution Plastics Institute at the University of Portsmouth, said: "What people are reporting on the ground is now unmistakable in the data. Plastics dominate the litter landscape, and some of the most affected places are not just city centres, but more rural and recreational environments that people associate with nature and escape".
Distinct material patterns were identified across the country. Paper and cardboard were most frequently recorded near schools, while cigarette butts and plastic items were concentrated around transport hubs, pointing to strong links between littering and the design of public spaces.
Citizen science projects are like brief flashes of light. Individually, they illuminate small areas, but when we bring them together using artificial intelligence, we can see the wider picture of how and where pollution is being found.
Hadiseh Rezaei, PhD student at the University of Portsmouth with a background in AI and Computer Networks
Hadiseh Rezaei, a PhD student at the University of Portsmouth with a background in AI and Computer Networks, said: "Citizen science projects are like brief flashes of light. Individually, they illuminate small areas, but when we bring them together using artificial intelligence, we can see the wider picture of how and where pollution is being found."
A key aim of the study was to protect valuable citizen science data from being lost. Many projects close or change over time, risking the disappearance of large volumes of environmental information.
Dr Farzad Arabikhan , from the School of Computing, University of Portsmouth, added: "Without this kind of harmonisation, we lose years of public effort and crucial environmental intelligence. Our method ensures that these contributions are preserved and turned into evidence that policymakers can use."
By linking citizen-generated data with mapping and census information, the study demonstrates how artificial intelligence can support targeted, evidence-based action to reduce pollution and improve waste management.
The authors believe the research provides robust national evidence to inform environmental policy and support more effective responses to plastic pollution.
