Bibliometric analysis of emerging contaminants and cytostatic compounds: understanding the current challenges

Abstract

Emerging contaminants (ECs) include a wide range of substances whose presence may pose a risk to the environment and human health. Research on cytostatic pollutants is increasing because the exponential growth of cancer treatments leads to higher discharge of cytostatic contaminants with wastewater treatment plant effluents. This systematic bibliometric review shows 4166 publications within the topic of ECs and cytostatic drugs in water bodies since 1996, mainly in the category of Environmental Science. China, Spain and USA are the most productive countries nowadays and Europe has 41,6 % of the publications. Research topics have shifted from identifying the presence of ECs, in the period 1996–2012, to understanding their fate, distribution, and long-term impacts as well as on developing removal technologies, in the period 2012–2023. 29 main keywords have been identified and classified into four thematic groups: contaminants, analytical techniques, water bodies and treatments. Principal component analysis has integrated them into two principal components (PC). PC1 includes keywords within the groups of water bodies and treatments, and it reflects 70 % of the original data variance; while PC2 represents the analytical topic, and it represents 20 % of the variance. The co-occurrence networks of keywords, analysed by VOSviewer, show four clusters in both periods, with “emerging contaminants”, “pharmaceuticals”, and “personal care products” as the most important. “Contaminants” that appear in the first period have been substituted by “treatment plants” in the last decade. The keyword “personal care products” shows the highest increase (14-fold), higher than “emerging contaminants” (13 times) and “cytostatic drugs” (10 times). In recent years, the research interest on the formation of transformation products during water treatments and their risks has increased as shown by the higher importance of keywords such as "transformation products", "risk assessment" and "toxicity”, as consequence of the development of advanced oxidation treatments.