Bridging Science and Policy on Terrestrial Plastic Pollution: A Bibliometric Analysis of Global Research Trends and African Governance Gaps

Existing plastic pollution research has focused predominantly on aquatic ecosystems, while the development, thematic evolution, and research performance of terrestrial plastic pollution remain underexplored. To address this gap, this study provides a comprehensive bibliometric and policy analysis of research on terrestrial plastic pollution, drawing on articles published in the Scopus and Web of Science databases from 1989 to 2026. Bibliometric analysis was conducted using the Biblioshiny package in RStudio, complemented by a review of African plastic policy frameworks. The results indicate that the field comprises 7682 publications by 18,797 researchers, generating 301,445 citations, with an average of 39.24 citations per article. Research output increased substantially after 2018, reflecting growing global concern about the environmental impacts of plastic contamination in terrestrial ecosystems. China, India, and the United States were the leading contributors to scientific output and international collaboration, while the Chinese Academy of Sciences was the most productive institution. Matthias C. Rillig was identified as the most prolific author in the field. Keyword and thematic analyses indicate that research on terrestrial plastic pollution has increasingly shifted from visible plastic waste to microplastic soil pollution and the ecological consequences of plastic contamination in terrestrial ecosystems. However, policy analysis reveals a disconnect between scientific evidence and policy responses in Africa, where most frameworks prioritize conventional plastic waste management and circular economy initiatives, giving limited attention to microplastic contamination and risks to terrestrial ecosystems. These findings highlight the need for policy reforms that integrate microplastic monitoring and soil protection into national plastic governance frameworks.