Micro- and Nanoplastics Research Surges but Stays Rooted in Environmental Toxicology

A new bibliometric analysis has charted the explosive growth of micro- and nanoplastics (MNP) research at the intersection of environmental pollution and human health, revealing a field that has scaled up at remarkable speed while remaining firmly rooted in environmental science and experimental toxicology. The study, published in Frontiers in Environmental Science, examined 2,068 English-language articles and reviews indexed in the Web of Science Core Collection between 2009 and 2025, using a search strategy that combined MNP terms with a broad set of health-related outcome terms. Its central finding is striking: 59.0 percent of the entire corpus was published in just 2024 and 2025, underscoring how rapidly scientific attention to plastic particles has accelerated.

The trajectory of publication output tells a vivid story of a young discipline finding its feet. Annual output remained at eight or fewer records per year through 2017, then climbed from 21 publications in 2018 and 31 in 2019 to 70 in 2020. From there the curve steepened dramatically: 132 records in 2021, 237 in 2022, 342 in 2023, 516 in 2024, and 704 in 2025.

The authors caution that this steep rise likely reflects several overlapping influences, including the broader expansion of MNP research overall, increased indexing and publishing capacity, growing early-access availability, and heightened funding and policy attention to plastic pollution. Publication volume, they stress, measures growing attention to potential health effects, not proof that those effects have been established in humans. Geographically, the field is dominated by China, which contributed 1,008 of the 2,068 records, nearly half the corpus, followed by the United States with 243, India with 152, Italy with 114, South Korea with 105, Germany with 95, and Spain with 94.

Yet the collaboration networks tell a more nuanced story. The United States held the highest total link strength in the country co-authorship network at 289, ahead of China at 251, indicating broader international connectivity despite its smaller output. The China–United States bilateral link was the strongest in the network with a link strength of 60, followed by Germany–United States at 17, Germany–China at 16, and India–United States at 15.

The collaboration map revealed distinct communities, including a China-centered group, an East Asia–North America group, continental and Mediterranean European clusters, and a group linking India, Pakistan, Iran, and partners in the Middle East and Africa. Institutional concentration reinforces this picture of rapid national scale-up. Of 2,702 organizations represented in the records, 214 met the five-publication threshold for network analysis, and the Chinese Academy of Sciences led with 88 publications, followed by Zhejiang University with 39, Nanjing University with 37, Nanchang University with 35, and Southeast University with 34.

Chinese institutions accounted for 25 of the 30 most productive institutions, or 83 percent. At the author level, however, the field appears fragmented: only 48 of the 183 threshold-meeting authors formed the largest connected component, drawn from a total of 10,973 authors overall. Links were dense within clusters but sparse between them, which the authors interpret as a sign that collaboration remains limited and the field is still at an emerging stage, consolidating its collaborative core rather than operating through mature, globally integrated consortia.

The publication venues themselves reveal where this science lives. Science of the Total Environment was the most frequent source with 196 records, followed by the Journal of Hazardous Materials with 151, Ecotoxicology and Environmental Safety with 121, and Environmental Pollution with 116. All ten leading journals were environmental-science or toxicology titles; no clinical medicine or general public-health journal appeared among the ten most productive sources.

This distribution matters because it locates the publication base of the field squarely within environmental science, even as health-facing concepts gain visibility in the literature's keywords and citation pathways. Keyword mapping brought the conceptual architecture of the field into focus. After thesaurus cleaning and a five-occurrence threshold, VOSviewer resolved 622 keywords into ten clusters linked by 23,556 connections.

The largest cluster concerned environmental pollution and endocrine disruptors, with terms such as endocrine disruptors, pollution, bisphenol A, fish, and marine environment. A second cluster centered on oxidative stress and toxicity, including polystyrene particles, apoptosis, and reproductive toxicity. A third linked MNPs with gut microbiota, inflammation, metabolism, and intestinal barrier function.

Further clusters represented nanoplastic neurotoxicity, particle properties and human health, toxicity in aquatic model organisms such as zebrafish and Daphnia magna, nanoparticles and cytotoxicity, genotoxicity, accumulation and reproductive health, and developmental toxicity. Notably, environmental and model-organism terms occupied large regions of the network, while specific disease terms such as cancer, atherosclerosis, obesity, and colorectal cancer were smaller and more peripheral. Temporal analysis sharpened this environmental-versus-clinical contrast.

Average publication years in the keyword overlay ranged from 2020.2 to 2025.0, with earlier terms including marine environment, ingestion, plastic debris, and persistent organic pollutants, while more recent terms included ferroptosis, pyroptosis, neuroinflammation, neurodegeneration, atherosclerosis, insulin resistance, infertility, lung, and placenta. Burst detection using CiteSpace identified 35 burst keywords, with the strongest bursts concentrated in environmental and marine topics: ingestion led with a burst strength of 10.26, followed by plastic debris at 9.67, European sea bass at 7.62, and the goby Pomatoschistus microps at 7.58. Microbiota dysbiosis began a burst in 2020, and the most recent bursts, beginning in 2023, included pharmaceuticals, glutathione, waste-water, and products.

Recent terms such as ferroptosis and neurotoxicity had not yet produced statistically detected bursts. The authors emphasize that these are descriptive signals of term timing and abrupt growth, not evidence of a disciplinary transition toward disease-oriented research. The most-cited records in the corpus further illustrate the field's foundations and its most clinically resonant moment.

The top-cited record, Teuten and colleagues' 2009 study on chemical transport from plastics to the environment and wildlife, had accrued 2,132 citations. Other highly cited early work addressed oyster reproduction, airborne microplastics, tissue accumulation in mice, gut barrier effects in mice and zebrafish, and plastic waste. The 2024 article by Marfella and colleagues in the New England Journal of Medicine, which reported an association between microplastics and nanoplastics detected in carotid artery plaques and subsequent cardiovascular events, had 827 citations by the retrieval date.

It was the only record among the ten most-cited that appeared in a clinical medical journal and directly related particles measured in human tissue to subsequent outcomes. The authors note that this observational association cannot establish causality, and that one highly cited article does not define field maturity. The study's methodological caution distinguishes it from earlier bibliometric work.

The authors explicitly frame their corpus as a query-defined environmental-health interface literature rather than a validated set of disease studies, because no title/abstract or full-text screening was used to classify records as disease research. Sensitivity analyses excluded 242 records from two high-volume journals, Science of the Total Environment and Chemosphere, and the main patterns held, with the proportion of 2024–2025 records actually rising from 59.0 to 62.8 percent. A cross-database concordance analysis using an adapted PubMed search returned 1,613 records, with annual counts strongly rank-correlated with the Web of Science series (Spearman ρ = 0.989), though the authors caution this reflects shared calendar-time growth rather than search precision.

DOI matching identified 1,427 shared records, corresponding to 69.0 percent of the Web of Science corpus and 88.5 percent of the PubMed set. An exploratory title/abstract screen within the PubMed set found oxidative stress in 597 records, reproductive or endocrine terms in 564, inflammation in 543, gut or intestinal biology in 502, cancer in 331, neurotoxicity in 326, apoptosis in 216, cardiovascular or metabolic terms in 164, and ferroptosis in 39, raw counts the authors insist should not be read as prevalence estimates. The broader context underscores why this map matters.

Recent human-evidence syntheses cited in the study screened thousands of records but identified only a small number of eligible in vivo human studies, with substantial exposure-measurement heterogeneity and moderate-to-high risk of confounding. Analytical advances have detected plastic particles in human blood, placenta, liver, lung, intestinal specimens, and brain tissue, demonstrating internal exposure, though detection alone does not establish a health effect. The bibliometric analysis itself does not estimate the proportion of direct human evidence or demonstrate any disciplinary transition.

The authors' conclusion is deliberately bounded: future health inference will require validated exposure measurement with contamination control, explicit polymer and particle-size characterization, harmonized reporting units, prospective studies with prespecified outcomes, and evidence syntheses that directly classify study design. Until then, the environmental-health interface of micro- and nanoplastics research remains, in bibliometric terms, an environmentally rooted field with growing health-facing ambitions.

Subject of Research: Bibliometric mapping of the environmental-health interface in micro- and nanoplastics research, 2009–2025

Article Title: Mapping the environmental-health interface in micro- and nanoplastics research: a bibliometric analysis, 2009–2025

Article References: Zhang, Y., Zhou, J., Liang, L., Wang, Z., Liang, X., Zhao, T., Zhou, J., Wang, L., & Lu, S. (2026). Mapping the environmental-health interface in micro- and nanoplastics research: a bibliometric analysis, 2009–2025. Frontiers in Environmental Science, 14, Article 1950726. https://doi.org/10.3389/fenvs.2026.1950726

Image Credits: AI Generated

DOI: 10.3389/fenvs.2026.1950726

Keywords: microplastics, nanoplastics, bibliometrics, environmental health, ecotoxicology, toxicology, human exposure, research trends, Web of Science, PubMed, oxidative stress, China