Global Evolution of Plastic Pollution Research (2015–2025): A Bibliometric and Thematic Assessment of Sustainability Challenges

Plastic pollution has emerged as one of the most pressing environmental, health, and socio-economic challenges worldwide, driving rapid growth in scientific research over the last decade. This study presents a comprehensive bibliometric analysis of global research on plastic particles as environmental contaminants published between 2015 and 2025. The search expression employed was (*plastic) AND (pollut* OR contaminat*) to retrieve publications addressing plastic pollution and the occurrence of plastics as environmental contaminants. A total of 50,946 documents, including articles, reviews, and book chapters indexed in the Scopus database, were analyzed using VOSviewer 1.6.20 and Bibliometrix/Biblioshiny v. 2026.01.1 Build 403 to evaluate publication trends, collaboration networks, conceptual structure, and the bibliometric organization of the field. The analysis revealed a sustained increase in scientific production, led by China (15,667 publications), the United States (5540), and India (5374), with Environmental Science representing the dominant subject area (31.2%). To characterize the most recent thematic structure, keyword co-occurrence analysis was specifically performed using articles published during 2024–2025. Keyword co-occurrence and thematic mapping identified microplastics, nanoplastics, and adsorption as the principal motor themes, while circular economy, sustainability, biodegradation, and machine learning emerged as rapidly expanding research directions. Author-productivity and journal-dispersion analyses revealed a concentrated scientific structure, characterized by a relatively small group of highly productive authors and a core set of journals accounting for a substantial proportion of the literature but with significant deviations from the theoretical Lotka and Bradford distributions. Furthermore, the collaboration analysis revealed an irregular geographic distribution of publication output and international co-authorship, with the largest absolute contributions concentrated in China, the United States, India, and several European countries. By integrating bibliometric indicators with policy frameworks, funding patterns, and sustainability perspectives, this study provides a system-level understanding of the evolution of research on plastic pollution. It identifies strategic priorities to support evidence-based environmental governance, circular economy implementation, and future research agendas.