Potentially toxic elements in groundwater: a hotspot research topic in environmental science and pollution research

A scientometric analysis based on the Scopus database was conducted to provide insight into research activities on the occurrence of potentially toxic elements (PTEs) (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, and Zn) in groundwater during 1970-2019. The selection of these PTEs was based on their significance concerning their reference frequency in environmental science and pollution research (ESPR) studies and their toxicity to living organisms. The analysis utilizes data about the quantity, type, journal, geographical, institutional, and funding patterns of publications. The results indicate that the publications' annual output has increased over the years, and especially after 2000, it presents a remarkable growth rate. The most studied PTEs were As and Pb; nevertheless, the research on the rest of PTEs cannot be neglected as it shows continuously increasing trends over time. The evolution of instrumentation and the dissemination of contamination case studies that affect a large part of the world population contributed significantly to the scientific community and relative stakeholders' interest. According to the analysis, the USA and China are the two principal countries with the most considerable contribution, producing the most research regarding the number of publications, research institutions, and funding sponsors. China owns the most influential research institution (i.e., Chinese Academy of Sciences) and largest funding sponsor (i.e., National Natural Science Foundation of China; ≈5% of global funding) on a worldwide scale due to its investment in research and development (R&D) and is expected to become the greatest force in the future.