Current Trends and Advances in Research on Rare Earth Elements (REEs) in Groundwater: A 2010–2025 Bibliometric Analysis

Abstract Rare earth elements (REEs) are becoming increasingly important in the global economy and environmental research, especially in studies of water circulation and water chemistry. The paper presents the results of a bibliometric analysis of studies on the presence of REEs in groundwater in the years 2010–2025. The analysis was based on 572 publications retrieved from the Scopus and Web of Science databases and analyzed using Biblioshiny and VOSviewer. The results indicate a dynamic development of the field, with an annual increase in publications of approximately 8.5%. A clear geographical differentiation in scientific productivity was observed, with dominance of China, the USA and Europe, while regions such as Africa and South America remain only marginally represented. Five main research trends were distinguished: hydrogeochemical processes, local studies, analytical techniques, REE transport, and anthropogenic pollution. Particular attention was paid to REE contamination in natural waters and their presence in acid mine waters. The results highlight the urgent need to establish natural background levels of REEs in aquatic environments, especially in the context of increasing contamination in industrialized regions. The lack of unequivocal findings on the impact of REE on health and the environment emphasizes the need for further intensive research.