What are the global patterns of microplastic ingestion by fish? A scientometric review.

The billions of tons of plastic released into the environment mostly fragment into smaller particles that reach rivers and oceans, posing toxicity risks to aquatic organisms. As fish serve as excellent environmental indicator organisms, this study aims to comprehensively review and quantify published data regarding the abundance of microplastics (MPs) ingested by fish through scientometric analysis. Systematic analysis reveals that global aquatic ecosystems are contaminated by MPs, with the characteristics of these contaminants stemming from inadequate disposal management practices. The abundance of MPs was recorded in several fish species, notably Cyprinus carpio in natural environments and Danio rerio in controlled environments. According to the surveyed studies, laboratory experiments do not accurately represent the conditions found in natural environments. The results suggest that, in natural environments, the predominant colors of MPs are blue, black, and red. Fibers emerged as the most prevalent type, with polyethylene (PE) and polypropylene (PP) being the most frequently identified chemical compositions. On the other hand, laboratory studies showed that the spheres and fragments ingested were predominantly polystyrene (PS) green, followed by the colors blue and red. This discrepancy complicates drawing accurate conclusions regarding the actual effects of plastic particles on aquatic biota. Given the enduring presence of plastic in the environment, it is imperative to consider and implement environmental monitoring for effective, long-term management.

Metals in species of the Cambeva (Teleostei: Trichomycteridae) genus of the Iguaçu River basin (Brazil).

The population growth is connected to the demand for resources and waste disposal in water. Metals are among several pollutants affecting aquatic ecosystems, posing risks to biota when in high concentrations. Metals can present a great danger to the aquatic ecosystem because they are not degradable and can bioaccumulate. Many rivers are already considered highly polluted. Among them is the Iguaçu River, located in southern Brazil, which is recognized for the Iguaçu Falls and its rate of endemism. One species of the Cambeva genus is among the endemic species found in the Iguaçu River and is threatened with extinction due to anthropization. Thus, we aimed to evaluate and compare the concentrations of copper, zinc, iron, lead, manganese, and cadmium in Cambeva stawiarski and Cambeva sp. 1 in four different streams of the Iguaçu River (Brazil). We collected 20 fish in two municipalities along the Iguaçu River tributaries. The results showed a statistical difference in the metal concentrations in different species and locations, mainly manganese, iron, and copper, observed in both species and municipalities and cadmium, which showed a statistical difference only for C. sp1. Fish from agricultural regions generally had the highest concentrations of metals, some above the permitted limits. Cadmium was found at high concentrations, generating great ecological concern since it is one of the most toxic metals, even in small quantities. The lack of limits in Brazilian legislation makes it challenging to predict the long-term effects of iron.

Glyphosate and its toxicology: A scientometric review.

Glyphosate (Gly) is a broad-spectrum herbicide and currently one of the most studied pesticides. New Gly-related data are published daily worldwide. Despite the large number of publications, there is no published scientometric revision that presently addresses this issue systematically. We aimed to scientometrically analyze the publication patterns of main topics related to Gly research. Web of Science data was obtained searching the topic "Glyphosate" (10,069 publications). Toxicology was the most influential area, and a subset was delimited containing the categories "Environmental Sciences", "Toxicology" and "Ecology" (2077 publications). The datasets were analyzed using Citespace. The publications number presented a high correlation with the Gross Domestic Product (GDP) in both datasets. USA was the leader of general publication about Gly, followed by Brazil, Canada and China. USA, Canada, Argentina, China and Brazil were the main countries in Gly toxicology. This subset was related with data of the GDP spending on Research & Developing and with the number of researchers by country. Thus, we ranked the main countries interested in the Gly and its toxicology and that invest their economic and human resources in these researches. Based on a keyword analysis by CiteSpace of the Gly toxicology, it was highlighted the "glyphosate-induced habitat alteration", that reflected the concern about Gly impact on agricultural and natural ecosystems. The researchers are also focused in studies involving AMPA (aminomethylphosphonic acid), the main Gly degradation product, the genotoxicity, herbicides mixture and in its presence in drinking water. More researches about Gly genotoxicity and carcinogenicity to humans are needed and more studies to compile the results of independent researches, such as meta-analytical reviews. Our study can support decisions and future efforts about Gly impacts and use, since more sustainable agriculture with less environment impact is important to the maintenance of ecosystem services and consequently the human health.

Analysis of global trends and gaps for studies about 2,4-D herbicide toxicity: A scientometric review.

2,4-dichlorophenoxyacetic acid (2,4-D) is a herbicide that is used worldwide in agricultural and urban activities to control pests, reaching natural environments directly or indirectly. The research on 2,4-D toxicology and mutagenicity has advanced rapidly, and for this reason, this review summarizes the available data in Web of Science (WoS) to provide insights into the specific characteristics of 2,4-D toxicity and mutagenicity. Contrary to traditional reviews, this study uses a new method to quantitatively visualize and summarize information about the development of this field. Among all countries, the USA was the most active contributor with the largest publication and centrality, followed by Canada and China. The WoS categories 'Toxicology' and 'Biochemical and Molecular Biology' were the areas of greatest influence. 2,4-D research was strongly related to the keywords glyphosate, atrazine, water and gene expression. The studies trended to be focused on occupational risk, neurotoxicity, resistance or tolerance to herbicides, and to non-target species (especially aquatic ones) and molecular imprinting. In general, the authors have worked collaboratively, with concentrated efforts, allowing important advances in this field. Future research on 2,4-D toxicology and mutagenicity should probably focus on molecular biology, especially gene expression, assessment of exposure in human or other vertebrate bioindicators, and pesticide degradation studies. In summary, this scientometric analysis allowed us to make inferences about global trends in 2,4-D toxicology and mutagenicity, in order to identify tendencies and gaps and thus contribute to future research efforts.