Visualization Analysis of the Research Status and Hotspots Track for Literature on Interactions between Microplastics and Microalgae

Microplastics, which pose a great threat to aquatic life and human health are widely distributed and existed for a long time in the water environment. As primary producers, microalgae are extremely sensitive to the toxic pollutants and can be utilized by high-trophic organisms, so they have been applied to assess the ecotoxicity of microplastics. In order to understand the current research status of the interaction between microplastics and microalgae, the related published papers of the interaction between microplastics and microalgae have been searched from Web of Science (WOS) from January 1, 2002 to May 31, 2022. Tools such as CiteSpace and VOSviewer have been used to visually analyze the authors, institutions and keywords from the 485 literatures, and to explore the research hotspots and research context. The bibliometric analysis results show that the research on the interaction between microplastics and microalgae is an emerging research direction in the field of ecotoxicology. Environmental Pollution (66 articles) and Science of the Total Environment (56 articles) are the two most published academic journals in the field. China has a strong interest in this field, and the number of publications is far higher than those of other countries. In addition, there is close cooperation among domestic institutions such as Tsinghua University, Ocean University of China and Chinese Academy of Sciences. Existing studies are focused on the ecotoxicity effects of microplastics on microalgae and the mechanism of toxicity, which are mainly evaluated from the dimensions and concentrations of microplastics, environmental impacts and other factors. A total of 18 microplastics and 28 microalgae species are involved, and Chlorella sp. is the most studied, followed by Chlamydomonas sp., Dunaliella sp. and Phaeodactyla sp. Potential toxicity, combined effects and trophic levels are the three research hotspots in this field. Microplastics can form composite pollutants with other contaminants in different ways and produce combined toxic effects, and the ecotoxicity and bioaccumulation effects of composite pollutants on microalgae, as well as their migration, transformation and potential toxicity in food chains are emerging trends in this field.