january-msemakweli/Microplastics-Bibliometric-Analysis: Mapping Global Research on Microplastic Sources, Environmental Pathways, and Health Implications: A Bibliometric Analysis (2000–2025)

Mapping Global Research on Microplastic Sources, Environmental Pathways, and Health Implications: A Bibliometric Analysis (2000–2025) Reproducible Web of Science–based bibliometrics for this study, implemented in R with bibliometrix. The full narrative, methods, code, and figures live in microplastics_bibliometric_analysis.Rmd. Authors Amelia Chebyala (1), January G. Msemakweli (2*), Oscar Punguti (3), Edson Protas (1), Iddi Mapande (1), Nelson Joseph Msacky (4), and Novatus Tesha (5) Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of, Department of Environmental and Occupational Health Johns Hopkins Bloomberg School of Public Health, Baltimore, United States, Department of Epidemiology Mbeya University of Science and Technology, Mbeya, Tanzania, United Republic of, Department of Medical Sciences and Technology Institute of Rural Development Planning, Dodoma, Tanzania, United Republic of, Department of Environmental Planning Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of, Department of Development Studies Corresponding author. E-mail: jmsemak1@jh.edu What this project does The analysis script: Imports WoS plain text exports from data/, merges them, and cleans duplicates (duplicatedMatching on titles) and publication years (2000–2025). Runs descriptive bibliometrics, annual and cumulative publication trends, top countries and journals, and highly cited papers. Builds collaboration networks (countries, institutions), keyword co-occurrence (Keywords Plus and author keywords), a thematic map, thematic evolution (three periods: 2000–2010, 2011–2017, 2018–2025), and co-citation networks (with matrix reduction for the reference network to keep plotting feasible). Adds trend topics, conceptual structure (MCA) on Keywords Plus, and health-related text analyses (keyword trends and carcinogenic/chronic proportions over time). Country-level publication counts are also written to country_publication_frequencies.csv in the project directory when you knit the document. Data Place Web of Science Core Collection exports as plain text (.txt) files under data/. The notebook loads every *.txt in that folder whose name contains savedrecs (typical WoS export names). Document types in the search should match your inclusion criteria (the manuscript describes Articles and Review Articles only). The Boolean query and date range used for retrieval are documented in the Methods section of the R Markdown file. Requirements R (recent version recommended) R packages: bibliometrix, ggplot2, dplyr, stringr (and Matrix, used for co-citation preprocessing—usually installed with bibliometrix dependencies) Install packages in R: install.packages(c("bibliometrix", "ggplot2", "dplyr", "stringr", "Matrix")) How to run Clone or download this repository. Ensure your WoS .txt exports are in data/ as described above. Open microplastics_bibliometric_analysis.Rmd in RStudio (or your preferred environment) and Knit to HTML. The code assumes the knit directory is the folder that contains the Rmd (the project root), so paths like data/ and output CSV names resolve correctly. Chunk caching is enabled (cache = TRUE); clear the cache folder if you change inputs or code and need a full rebuild. Repository layout | Path | Role | | ------------------------------------------- | ------------------------------------------- | | microplastics_bibliometric_analysis.Rmd | Main analysis notebook | | data/ | WoS plain text exports (savedrecs*.txt) | License See LICENSE in this repository.