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Article

Research Trends on Coal Tar in Infrastructure Decommissioning: A Systematic Review Revealing Scientific Performance and Knowledge Gaps

1, 2, 2, 3★, 2, 4, 1, 1, 5, 5, 6, 7, 1★ Corresponding author

  1. 1Programa de Engenharia Nuclear, Universidade Federal do Rio de Janeiro, BRAZIL.
  2. 2Biofísica, Universidade Federal do Rio de Janeiro, BRAZIL.
  3. 3Seção de Engenharia Nuclear, Instituto Militar de Engenharia, BRAZIL.
  4. 4Biologia Geral, Universidade Federal Fluminense, BRAZIL.
  5. 5Física da Terra e do Meio Ambiente, Universidade Federal da Bahia, BRAZIL.
  6. 6Oceanografia, Universidade Federal da Bahia, BRAZIL.
  7. 7Biologia Marinha, Universidade Federal do Rio de Janeiro, BRAZIL.

CORRESPONDENCE

José Marques Lopes

Seção de Engenharia Nuclear, Instituto Militar de Engenharia, BRAZIL.

jose.marques@ime.eb.br

Received: 21-07-2026; Revised: 07-08-2026; Accepted: 16-09-2026.

Volume 15, Issue 3 · pp. 1107–1119 · 2026 · DOI: 10.5530/jscires.20260203

View on JSCIRES original site ↗

ABSTRACT

Coal tar and its derivatives have long been recognized for their industrial applications and environmental significance due to the presence of Polycyclic Aromatic Hydrocarbons (PAHs). This study presents a comprehensive analysis of scientific research on coal tar, encompassing its environmental and toxicological impacts, structural applications, and the use of Computational Fluid Dynamics (CFD) for computational modeling. A dataset of 6,805 documents from the Scopus database was analyzed. Thematic mapping revealed that the retrieved coal tar research predominantly focuses on environmental contamination and PAH characterization, whereas industrial process studies and CFD applications appear less frequently represented within these specific parameters. Strategic diagram analysis classified research clusters into motor themes, specialized but isolated topics, basic transversal subjects, and emerging or declining areas. Notably, CFD modeling of coal tar behavior represents a prospective area for further exploration within the mapped literature. This analysis highlights well-established knowledge and potential opportunities for expansion, identifying priority areas for future research, including environmental risk assessment, material applications, and numerical modeling of coal tar and PAHs.

KEYWORDS

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INTRODUCTION

Tar-derived materials, particularly those originating from coal tar, have historically played a critical role in industrial corrosion protection (Serednitskii et al., 1987; Velazquez et al., 2009). From the 1930s through the 1980s, Coal Tar Enamels (CTEs) were extensively applied to pipelines and maritime structures due to their strong adhesion, low permeability, and chemical resistance (Merten, 2017; Yin et al., 2018). These coatings were regarded as highly valuable technical solutions, especially for projects exposed to harsh saline environments and prolonged immersion.

However, from the mid-20th century onwards, scientific investigations began to reveal the environmental and toxicological risks associated with these materials. Coal tar-based products contain high concentrations of Polycyclic Aromatic Hydrocarbons (PAHs), a class of organic pollutants that are persistent, bioaccumulative, and toxic (Ghosh et al., 1974; Kay, 1976; Li et al., 2011; Feng et al., 2015). Initial studies primarily focused on exposure and localized contamination, but over time, attention expanded to encompass broader ecological and human health risks, particularly in aquatic environments (Marvin et al., 1995; Kocan et al., 1996; Bryer et al., 2006; McIntyre et al., 2016). Due to their toxicity, the use of coal tar as a sealant in subsea pipelines has become increasingly restricted (Husain et al., 2004), and several regions, including the United States, Europe, and Japan, have banned its use.

While much of the literature has concentrated on PAH toxicity, contaminated sediments, and exposure pathways, relatively little is known about the legacy impacts of these materials in marine environments (Coulon et al., 2009; Stout and Brey, 2019; Temel et al., 2024). Many older subsea pipelines and maritime structures coated with CTEs remain in operation or were decommissioned in past decades without comprehensive environmental risk assessments (Francis, 2015; Capobianco et al., 2022).

With growing awareness of their ecological and toxicological risks, particularly in aquatic systems, international regulatory frameworks were established to restrict the use of these materials (Van et al., 2005; GC, 2023) and promote the development of safer alternatives (Dennis et al., 2015; 2016). Initiatives such as the European Union’s REACH legislation and the Stockholm Convention on Persistent Organic Pollutants (POPs) have significantly reshaped both the scientific and industrial landscapes, prioritizing the management and remediation of hazardous substances. These advances spurred increased environmental research and ecotoxicological assessments of tar-derived materials, though certain topics, particularly those related to marine structures, have remained relatively underexplored.

Similarly, modern analytical and modeling tools, such as Computational Fluid Dynamics (CFD) and coupled biogeochemical models to simulate the behavior and fate of these complex mixtures, have not been widely applied to evaluate the dispersion, leaching, or degradation dynamics of coal tar coatings in marine settings. Such techniques could substantially enhance our understanding of residual contamination and its environmental implications.

In this context, bibliometric analysis emerges as a valuable approach for systematically mapping the evolution of research on tar-derived materials, identifying thematic concentrations, and highlighting underexplored niches. By analyzing publication trends, collaboration networks, and thematic clusters, this study aims to provide a comprehensive overview of scientific output in the field, revealing patterns, critical knowledge gaps, and emerging opportunities for future research.

Accordingly, this study conducts a bibliometric analysis to systematically map the scientific literature on coal tar-derived materials, with an emphasis on offshore and marine applications. Through keyword co-occurrence analysis, thematic clustering, and citation mapping, it identifies prevailing research trends and underexplored areas within the discipline. Special attention is given to gaps in the environmental risk assessment of legacy infrastructure and to opportunities for interdisciplinary research that integrates environmental science, ocean engineering, and computational modeling.

By highlighting the historical development, current research frontiers, and regional disparities within the literature, this review offers a roadmap for future investigations, especially in developing economies with aging and abandoned offshore infrastructure, such as Brazil. It also seeks to support regulatory agencies, environmental managers, and industry stakeholders in formulating science-based guidelines for the decommissioning and ecological monitoring of tar-derived materials.

METHODOLOGY

Database

A methodological approach using bibliometric analyses was employed. We integrated several tools to provide a more comprehensive understanding of our main subject. Figure 1 shows the main steps, from database selection to graphical analysis. The Scopus database was used to collect bibliometric information. The choice was made because Scopus has a database with over 53 million references published in more than 24,000 scientific journals (Vasconcelos et al., 2020; 2023). The Scopus web access system offers a variety of tools that enable efficient literature searches in specific fields, whether basic or advanced research. These resources facilitate the rapid and consistent acquisition of information, offering a detailed and comprehensive overview.

Figure 1: Diagram of the methodological sequence employed in this study.

The choice of keywords

A search strategy was formulated using targeted keywords and Boolean operators aiming to maximize the retrieval of relevant literature while minimizing thematic deviations. Initially, articles on coal tar were retrieved without additional filters. In later stages, separate sets of keywords were used to search for articles on structures, HPA, toxicology, and computational simulation. The specific search commands are detailed in Table 1. The selection of these four specific subsets was intentionally established to construct a comprehensive evaluation framework. Together, these domains represent the critical multi-disciplinary pillars required to assess the environmental liabilities, material degradation, and ecological risks associated with the decommissioning of legacy offshore and marine infrastructure.

Table 1: Set of keywords used to search for articles in the Scopus database.
RestrictionSearch only in: Title, Abstract or Keywords
Without distinction of area (6,805 documents found)( TITLE-ABS-KEY ("coal tar") OR TITLE-ABS-KEY (coal-tar) OR TITLE-ABS-KEY ("petroleum tar") OR TITLE-ABS-KEY (petroleum-tar) OR TITLE-ABS-KEY ("tar pitch")) AND PUBYEAR > 1845 AND PUBYEAR < 2025 AND ( LIMIT-TO ( DOCTYPE, "ar")) AND (LIMIT-TO (SRCTYPE, "j") OR LIMIT-TO (SRCTYPE, "d")) AND (LIMIT-TO(SUBJAREA, "CHEM") OR LIMIT-TO (SUBJAREA, "CENG") OR LIMIT-TO (SUBJAREA, "ENER") OR LIMIT-TO (SUBJAREA, "ENGI") OR LIMIT-TO (SUBJAREA, "ENVI") OR LIMIT-TO (SUBJAREA, "PHYS") OR LIMIT-TO (SUBJAREA, "EART") OR LIMIT-TO (SUBJAREA, "BIOC") OR LIMIT-TO (SUBJAREA, "PHAR") OR LIMIT-TO (SUBJAREA, "AGRI") OR LIMIT-TO (SUBJAREA, "COMP") OR LIMIT-TO (SUBJAREA, "MATH") OR LIMIT-TO ( SUBJAREA, "IMMU")) AND (LIMIT-TO (LANGUAGE, "English")) AND (LIMIT-TO ( PUBSTAGE, "final")).
Focused on structure (120 documents found)(TITLE-ABS-KEY ("coal tar") OR TITLE-ABS-KEY (coal-tar) OR TITLE-ABS-KEY ("petroleum tar") OR TITLE-ABS-KEY (petroleum-tar) OR TITLE-ABS-KEY ("tar pitch") AND TITLE-ABS-KEY (pipeline*)) AND PUBYEAR>1972 AND PUBYEAR<2025 AND (LIMIT-TO (DOCTYPE, "ar")) ".
Focused on HPA (736 documents found)(TITLE-ABS-KEY ("coal tar") OR TITLE-ABS-KEY ( coal-tar) OR TITLE-ABS-KEY ("petroleum tar") OR TITLE-ABS-KEY (petroleum-tar) OR TITLE-ABS-KEY ("tar pitch") AND TITLE-ABS-KEY (pah) OR TITLE-ABS-KEY (polycyclic AND aromatic AND hydrocarbon*) AND NOT TITLE-ABS-KEY (toxicit*)) AND PUBYEAR>1845 AND PUBYEAR<2025 AND (LIMIT-TO (DOCTYPE, "ar").
Focused on toxicology (215 documents found)(TITLE-ABS-KEY ("coal tar") OR TITLE-ABS-KEY (coal-tar) OR TITLE-ABS-KEY ("petroleum tar") OR TITLE-ABS-KEY (petroleum-tar) OR TITLE-ABS-KEY ("tar pitch") AND TITLE-ABS-KEY (toxicit*)) AND PUBYEAR>1845 AND PUBYEAR<2025 AND (LIMIT-TO (DOCTYPE, "ar").
Focused on computational simulation (13 documents found)(TITLE-ABS-KEY ("coal tar") OR TITLE-ABS-KEY (coal-tar) OR TITLE-ABS-KEY ("petroleum tar") OR TITLE-ABS-KEY (petroleum-tar) OR TITLE-ABS-KEY ("tar pitch") AND TITLE-ABS-KEY ("computational fluid dynamics")) AND PUBYEAR>1845 AND PUBYEAR<2025 AND (LIMIT-TO (DOCTYPE, "ar").

The final keyword selection was refined through multiple iterations, adjusting based on the returned results. This optimized combination, along with logical connectors, aimed to minimize thematic deviations and streamline the inclusion of literature relevant to our research framework.

Following the initial data retrieval, a data cleaning process was conducted to ensure dataset integrity. Due to the precision of the Scopus indexing system, duplicate entries were found to be minimal and were readily removed. Furthermore, a manual screening of titles and abstracts was performed to eliminate false positives and exclude irrelevant documents that did not align with the core environmental, toxicological, or engineering themes of this study. The search strategy applied in the Scopus database was refined through a set of restrictions designed to ensure the thematic relevance, document quality, and consistency of the retrieved data. These restrictions included limitations by document type, source type, subject area, language, and publication stage, as summarized in Table 2.

Table 2: Description of the restrictions applied in the Scopus database search strategy to ensure the relevance, quality, and thematic consistency of the retrieved documents.
RestrictionDescription
LIMIT-TO (DOCTYPE, "ar")Selects only full research articles, excluding other document types such as reviews, conference papers, editorials, or letters. Ensures the inclusion of original and complete studies.
LIMIT-TO (SRCTYPE, "j") OR LIMIT-TO (SRCTYPE, "d")Restricts the sources to scientific journals (j) and serial publications (d), excluding books, book chapters, or conference proceedings. Ensures that documents originate from peer-reviewed, periodical publications.
LIMIT-TO (SUBJAREA,...)Limits documents to specific subject areas in Scopus, selected according to their relevance to the study:
  • CHEM - Chemistry
  • CENG - Chemical Engineering
  • ENER - Energy
  • ENGI - Engineering
  • ENVI - Environmental Science
  • PHYS - Physics and Astronomy
  • EART - Earth and Planetary Sciences
  • BIOC - Biochemistry, Genetics and Molecular Biology
  • PHAR - Pharmacology, Toxicology and Pharmaceutics
  • AGRI - Agricultural and Biological Sciences
  • COMP - Computer Science
  • MATH - Mathematics
  • IMMU - Immunology and Microbiology
LIMIT-TO (LANGUAGE, "English")Includes only articles published in English, the dominant language in international scientific communication, ensuring accessibility and standardization for analysis.
LIMIT-TO (PUBSTAGE, "final")Considers only documents in the final publication stage, excluding in-press, preprints, or early-access documents. Ensures that only peer-reviewed, indexed, and officially published articles are analyzed.

It is worth noting that the specific keyword boundaries established in this methodology might affect the perceived size of certain research niches, potentially under- or overrepresenting technical subareas where alternative terminology or adjacent descriptors are preferred.

Statistical of results

The Bibliometrix package, developed for the R statistical environment, was employed to perform the bibliometric analysis. This software suite offers resources for quantifying and visualizing scientific production patterns, including citation metrics, co-authorship mapping, and identifying thematic trends within the literature (Aria and Cuccurullo, 2017; Derviş, 2019). All analyses and graphical representations were generated using R version 4.0.4, integrated with RStudio version 1.4.1106, the ggplot2 package version 3.3.5, and Bibliometrix version 3.1.4.

Co-occurrence Term Mapping

VOSviewer version 1.6.17 was applied to conduct both quantitative and qualitative analyses of the selected publications to construct co-occurrence networks of terms. This software allows for the visualization and analysis of bibliometric networks, including co-authorship, co-citation, and keyword co-occurrence. Through its interactive features, VOSviewer facilitates the detection of research clusters and emerging topics in the field (Van and Waltman, 2014; Perianes-Rodriguez et al., 2016). This study generated co-occurrence maps based on the combined data from article titles, abstracts, and keywords. A threshold value was established for the minimum frequency of term occurrence to refine the resulting networks. Further details regarding the co-occurrence maps and their interpretation are presented in the Results and Discussion section.

RESULTS AND DISCUSSION

Tar-derived materials have attracted sustained scientific community's interest over the past decades (Figure 2). The earliest known work on tar-derived material dates back to 1846 (Anderson, 1846), a paper aimed at deepening the understanding of the constitution and properties of picoline, an organic base derived from coal tar, and its implications for organic chemistry. A total of 12 publications were identified in the 19th century, suggesting that the applications of tar-derived materials were considered promising at that time.

Figure 2: Comparison of Publications on Tar-derived Materials Related to Marine Oil and Gas Extraction Lines.

As illustrated in Figure 2, indexed publications on this topic exhibit a substantial upward trend in recent decades, with a noticeable intensification since the beginning of the 21st century. Additionally, introductory queries in the Scopus database for recent publication years indicate that this momentum is sustained, reflecting ongoing scientific output. This expanding literature is widely discussed as being responsive to emerging environmental, public health, and industrial concerns, where various regulatory initiatives appear to have further propelled these investigations.

One of the first steps towards implementing regulatory policies was when the European Commission presented the first draft of a major revision of European chemicals management legislation (EC, 2003). This proposal, known by the acronym "REACH" (Registration, Evaluation, and Authorization of Chemicals), represented a significant shift in the way risks associated with chemicals were to be managed within the European Union. It required the registration and authorization for the use of substances of very high concern, such as tar-derived materials.

Around the same period, the Stockholm Convention on Persistent Organic Pollutants (POPs), adopted in 2001 and enforced in 2004, emerged as an important step in the global fight against pollution and its harmful effects on health and the environment (Lallas, 2001). The convention had a significant impact on scientific research, public health, and environmental awareness, to the point that it continues to shape how Persistent Organic Pollutants are addressed worldwide (Xu et al., 2013), including in developing countries (Akinrinade et al., 2024).

In the United States, the Environmental Protection Agency (EPA) leads studies on environmental and human health risks (EPA, 2020). Several states have banned coal tar sealants on public roadways following findings of contamination by Polycyclic Aromatic Hydrocarbons (PAHs) (Mahler et al., 2012; Needleman, 2015).

However, despite several regulatory milestones, the retrieved data suggest that topics addressing marine oil and gas extraction structures appear less frequently represented compared to total number of publications on tar-derived materials within this specific dataset. Studies focusing on PAHs within this specific context show some, albeit limited, prominence in the mapped literature. It is noteworthy, given the environmental significance of analyzing such extracts due to their contamination potential. Nevertheless, the toxicity of tar-derived materials appears to be a more specialized niche in terms of indexed publication numbers. Within this parameter, the most cited documents are published in open access journals and date from before 2010 (Mueller et al., 1991; Collins et al., 1998; Neff et al., 2005). Furthermore, when applying an additional exploratory search filter to include the explicit term 'ocean' in the abstract, title, or keywords, only four articles were retrieved (Simpson et al., 2020; Wu et al., 2022; Yang et al., 2018; Oziolor et al., 2014), highlighting how specific terminology choices can significantly restrict document retrieval in these subfields.

Regarding pipelines, the 120 documents retrieved indicate that research specifically linking coal tar to offshore or marine structures appears to be relatively limited compared to broader industrial applications. Interestingly, coal tar enamel was the primary pipeline coating material between the 1930s and 1980s due to its excellent chemical resistance. Its current disuse is attributed to its environmental persistence and the leaching of PAHs, which limited its modern applications, leading to its gradual replacement by alternative coatings (Jagtap et al., 2014; Dennis et al., 2015; Dennis et al., 2016). However, a notable increase in publications was observed when comparing previous years to 2024, with an average of two articles per year rising to 26, within this specific pipeline subset.

Finally, when applying a filter to identify studies involving Computational Fluid Dynamics applications in coal tar research, only 13 publications matched the search string. Most of these works are focused on modeling processes or optimization mechanisms (Seo et al., 2024; Rezapour and Deymi-Dashtebayaz, 2024; Singh et al., 2024; Yun et al., 2024) or on simulating the influence of degrading factors (Gera et al., 2001; Zeng et al., 2011; Chen et al., 2021; Isa et al., 2019).

This context suggests that the scientific community's interest, as reflected in the retrieved research, appears to be more oriented toward new types of coatings, optimization of installation processes and applications, and the assessment of extracts for contaminant analysis. The gathered data indicate that comparatively fewer indexed studies explicitly address the environmental impacts of legacy coal tar enamel coatings applied to pipelines, particularly those installed in the early to mid-20th century.

The publications produced over time showed that China leads in the number of publications in the field of tar-derived materials, followed by the United States. Figure 3 illustrates the contribution of each country to research on tar-derived materials, along with the number of studies involving international collaborations (Single Country Publication-SCP; Multiple Country Publication-MCP). This distribution reflects common bibliometric trends, since single-country publications often benefit from uniformity and proximity. In contrast, multiple-country publications encounter additional layers of complexity related to coordination, regulation, and communication, making them more challenging to execute and publish (Sweileh et al., 2016). Nevertheless, the literature suggests that although MCPs are more demanding, international collaborations can enhance citation impact and increase the potential for globally relevant innovation.

Figure 3: Number of corresponding authors' countries and their collaborations.

Interestingly, among the ten institutions with the most publications, five are based in China: the Ministry of Education of the People's Republic of China, the Chinese Academy of Sciences, Northwest University, Taiyuan University of Technology, and the China University of Mining and Technology. Two others are Spanish institutions: CSIC - Instituto de Ciencia y Tecnología del Carbono INCAR, and the Consejo Superior de Investigaciones Científicas. Additionally, one French, one British, and one Russian institution appear in this ranking: CNRS (Centre National de la Recherche Scientifique), Imperial College London, and the Russian Academy of Sciences, respectively.

In this context, North American institutions are notably absent from the top ranks, with the University of Notre Dame appearing only in the 21st position. This indicates a shift in publication volume, suggesting that U.S. institutions focus on more specialized subfields rather than leading in gross document count within this specific dataset. Their efforts are directed primarily toward areas emphasizing sustainability and/or energy production (LaVerne and Kleemola, 2017; Choi et al., 2011), or in varied applications with a focus on environmental and energy-related issues (Wang et al., 2020; Tarábek et al., 2009; LaVerne et al., 2020; Lisovskaya et al., 2019).

While the retrieved scientific literature highlights specific consumer product regulations in China (Wang, 2006), industrial regulatory frameworks are less frequently discussed within the analyzed academic dataset. Meanwhile, U.S. institutions are increasingly concentrated in research areas such as nanomaterials and renewable energies.

This condition explains the countries' collaboration map presented in Figure 4. The figure shows the existence of three distinct collaboration clusters. The first cluster is led by the United States, which maintains strong collaborative ties with European Union countries and Canada - the latter also stands out for its firm commitment to renewable energy use and regulatory initiatives (Anderson and Gough, 2022; CEP, 2025). A second cluster is headed by China, in association with countries typically from Eastern Europe and India. Spain leads a third, more discrete cluster, demonstrating intense collaboration with Central and South American countries. It is mainly due to the activity of the CSIC - Instituto de Ciencia y Tecnología del Carbono INCAR, which stands out as Spain's leading public research agency and one of the most active globally in establishing international partnerships.

Figure 4: Mapping International Collaborations and Cluster Formation.

In this context, Brazil, which is representative of developing countries, has preferentially published articles in journals focused on environmental chemicals. The most frequently chosen journals include Chemosphere (10), Fuel Science and Technology International (5), Journal of Applied Polymer Science (4), and Energy and Fuels (4). Interestingly, and further reaffirming the importance of the Spanish cluster within the collaboration network, in the context of publications involving Brazil, the Universitat de Barcelona appears as the most relevant institution, with 18 articles.

Figure 5 shows how topics involving coal tar have developed based on the more generic search string presented in the methodology. It was observed that, to obtain a visually acceptable graph, it was necessary to restrict the graph's generation to 350 words with 5 citations per year; otherwise, the high density and overlapping of terms would compromise the visual clarity and interpretation of the thematic trends. In this context, the term 'polycyclic aromatic hydrocarbon' exhibits a prominent position among the trend topics throughout the analyzed period. This frequency aligns with expected literature patterns, since coal tar is a complex mixture rich in Polycyclic Aromatic Hydrocarbons (PAHs), which are closely associated with its toxicological and environmental relevance (Abdel-Shafy and Mansour, 2016; Barbosa Jr et al., 2023; Vijayanand et al., 2023). In recent years, the retrieved data suggest that studies on coal tar have expanded beyond conventional assessments of PAHs, incorporating additional concepts such as molecular weight (Balastegui et al., 2024; Kim et al., 2020; Chibwe et al., 2017), carbon structure characterization/application (He et al., 2012; Rocha et al., 2010), and radiation-induced chemical processes (Kumar et al., 2015; Wang et al., 2021). These trends potentially highlight an increasing interest in molecular-level understanding and innovative treatment approaches for coal tar-contaminated environments within the mapped dataset.

Figure 5: Bibliometric analysis of trending topics in tar-derived materials research.

The keyword co-occurrence analysis facilitated the mapping of prominent thematic fields related to research on coal tar, PAHs, their environmental and toxicological impacts, their application in tubular structures, and analyses using CFD through the formation of distinct clusters (Figure 6). The ‘full counting’ technique was applied because it allows measuring the raw frequency of each term. The number of co-occurrences was carefully calibrated to optimize network readability and ensure a clear visual analysis of these relationships. The information after these threshold definitions is presented in Table 3.

Figure 6: Keyword co-occurrence for coal tar: (a) without restrictions (General), restricted to (b) PAHs (subset), (c) Toxicology, (d) Pipelines, and (e) Computational Modelling.
Table 3: Details of the restrictions applied for generating co-occurrence maps.
keyword co-occurrenceTotal link strengthNumber of documents Analyzed
ItemsClustersLinks
General393716390246802
Structure395287637120
HPA (extract)40475617083735
Toxicology4046876971215
Modeling22213118713

In the more general search, considering the restrictions listed in Table 3 (Figure 6a), terms were grouped into three major thematic clusters: (i) carbonization processes and coal treatment (carbonization, coal tar, coal tar pitch, carbon), (ii) aromatic hydrocarbons and environmental contamination (aromatic hydrocarbons, polycyclic aromatic hydrocarbons, PAH, naphthalene), and (iii) applied chemistry and environmental monitoring (chemistry, degradation, oxidation, environmental monitoring). This grouping illustrates the close alignment between the characterization of chemical contaminants, the industrial processes involved, and environmental control strategies. Regarding bibliometric relevance, the results suggest a central focus on studies addressing environmental contamination and industrial processes within the retrieved scope. The connection network further points to the role of coal tar in discussions on environmental degradation and mitigation methods. This overview highlights, from a bibliometric perspective, a notable representation of coal tar within this database when no additional filters are applied.

When restrictions are applied to scientific trends, the results are as follows: In the PAHs-focused search (Figure 6b), four clusters stand out: (i) PAH chemical characterization (polycyclic aromatic hydrocarbons, naphthalene, phenanthrene, pyrene), (ii) toxicological studies and risk assessments (controlled study, risk assessment, human), (iii) soil and sediment contamination (soil pollution, sediment, biodegradation), and (iv) analytical techniques and environmental monitoring (environmental monitoring, mass spectrometry, gas chromatography). The term ‘polycyclic aromatic hydrocarbons’ was the subset's most frequent and cited keyword, underscoring its relevance in contamination and environmental risk studies captured by the query. Gas chromatography exhibits high network centrality, indicating it as a widely used technique in PAH analysis. It is strongly connected to: mass spectrometry, reflecting the typical application of GC-MS; compounds such as naphthalene, phenanthrene, pyrene, and anthracene, all frequently analyzed by this technique; and molecular weight, highlighting the focus on the detailed characterization of these substances. Even within this specific subset, the key compounds and application areas remain visible, with strong connections to environmental and toxicological clusters. This suggests how laboratory methods support these studies and integrate with risk analyses and environmental assessments within the mapped literature.

The analysis of connections suggests that a significant portion of the retrieved literature concentrates efforts on evaluating the impacts of PAHs on aquatic and terrestrial environments, as well as on degradation processes and the monitoring of persistent pollutants. The ten most cited papers in this context show a focus on human health consequences (Jongeneelen et al., 1987; Boffetta et al., 1997), PAH studies, environmental impacts, and bioremediation processes (Mueller et al., 1989; Ghosh et al., 2003; Vidya et al., 2004; Smith et al., 2006; Sofowote et al., 2008), analytical techniques (Wise et al., 1988), and catalytic reforming (Guo et al., 2018).

From the toxicological perspective (Figure 6c), the terms were organized into four main groups: (i) animal testing and toxicity studies (animal experiment, controlled study, toxicity testing), (ii) environmental pollutants and PAHs (aromatic hydrocarbons, PAH, polycyclic aromatic hydrocarbons), (iii) soil and water contamination (contamination, soil pollution, water pollutant), and (iv) chemical processes and environmental degradation (chemistry, radiolysis, toxicity). The network of connections indicates the visibility of coal tar and PAHs in toxicological studies, highlighting their importance as priority contaminants in marine (Neff et al., 2005; Huang et al., 2014; Yang et al., 2018; Shi et al., 2023) and terrestrial environments (Long et al., 2017; Aabbar et al., 2024), as well as the potential human health risks associated with such exposures (Mueller et al., 1991; Linak et al., 2007; Li et al., 2011).

In the subset focused on coal tar in structural applications (Figure 6d), four thematic clusters stood out: (i) chemical and gas industries (chemical industry, gas industry, petroleum transportation), (ii) anticorrosive protection (cathodic protection, coal tar, coating, corrosion protection), (iii) pipeline infrastructure (natural gas pipelines, water pipelines), and (iv) corrosion and energy (coal, corrosion, pipeline corrosion). This grouping highlights the historical importance of coal tar as an anticorrosive coating, particularly in hydrocarbon transport systems, aligning with historical accounts regarding its durability in aggressive and industrial environments. In this context, enamel appears as a relevant keyword in co-occurrence analyses. Coal tar enamel is a protective coating known for its corrosion resistance and durability. It is typically applied to metallic surfaces and is particularly effective in harsh environments (Yin et al., 2018; Coates, 1991; Linchtenstein, 2003). Although coal tar enamel is still in use, the analyzed trends reflect that it has been gradually replaced by safer, more sustainable alternatives in recent decades (Jagtap et al., 2014; Dennis et al., 2015; Dennis et al., 2016).

Lastly, in the CFD-focused search (Figure 6e), the terms were grouped into two clusters: (i) numerical modeling and computational fluid dynamics (computational fluid dynamics, coal tar) and (ii) industrial processes involving petroleum derivatives (petroleum tar). The connection analysis reinforces the seemingly incipient application of computational modeling in coal tar analysis, with this refined search returning a limited set of 13 documents. This restricted number of studies makes it challenging to identify definitive observational patterns or established research niches. Each of the 13 papers addresses specific, highly distinct situations, ranging from secondary reactions (Zeng et al., 2011) to cavitation in centrifugal pumps (Yun et al., 2024). This characteristic suggests a potential thematic fragmentation within this specific dataset, which may point to an underexplored niche.

The limited number of studies potentially reflects the inherent challenges associated with modeling the highly complex composition of this mixture (Russo et al., 2019; Koolen et al., 2015; Niemeier, 2001), which complicates the definition of physicochemical properties for modeling. Additionally, a shortage of experimental data for validation and a predominant focus on chemical and toxicological analyses have limited the application of CFD in this context.

Overall, the visualization networks demonstrate a strong interconnection between industrial processes, soil and water contamination, toxicological impacts, and environmental monitoring strategies, with coal tar and PAHs standing out as central objects of investigation.

The results from keyword co-occurrence corroborate those presented in Figure 7, representing a thematic strategic map in the development degree (density) vs. relevance degree (centrality) plane. Thematic analysis based on the relationship between development and relevance levels identifies the strategic positioning of predominant subjects in the literature. The cluster formed by coal tar, results, study, and chemical occupies the motor theme position, characterized by high density and centrality, suggesting that these highly frequent terms are deeply integrated with other research topics, representing a central thematic concentration within this dataset.

Figure 7: Thematic strategic diagram of coal tar-related research based on development and relevance degrees.

Conversely, topics such as pitch, carbon, temperature, obtained, and method are highly developed but display low centrality, representing specialized and isolated themes. This position suggests that, despite being well developed, these topics have limited interaction with other thematic clusters, potentially indicating segmented research lines or highly specific techniques not closely linked to environmental or toxicological issues.

Meanwhile, the cluster comprising products, water, society, reaction, and rate appears in the basic themes zone, denoting moderate centrality and low density. These terms appear to function as transversal concepts, frequently present in various studies, reflecting lower internal thematic density within this specific dataset. This positioning suggests their role as support elements for different research lines, showing a more dispersed structure in the current retrieved literature.

Finally, special attention is warranted for the group formed by aromatic, compounds, hydrocarbons, polycyclic, and concentrations, located in the emerging or declining themes zone, indicated by low density and centrality. This position could signal either the recent emergence of new approaches involving these compounds - such as studies of their behavior in aquatic environments or their computational modelling via CFD - or a progressive decline in interest within more recent literature. Considering the historical environmental and toxicological significance of polycyclic aromatic hydrocarbons, it is plausible that this cluster represents an opportunity for the resumption and updating of research, particularly from the perspective of environmental dynamics in aquatic and petroleum systems, areas which appear to have significant potential for expansion regarding numerical modelling applications.

CONCLUSION

This review offers a comprehensive overview of global scientific research on coal tar and its derivatives over the past century, highlighting key trends, potential literature boundaries, and emerging opportunities within the analyzed dataset. The analysis suggests that most indexed studies have focused on environmental contamination and Polycyclic Aromatic Hydrocarbon (PAH) characterization, a trend seemingly driven by regulatory frameworks. However, critical areas such as industrial applications (especially pipeline coatings) and computational modelling using CFD appear to be less prominently represented within these specific search parameters. While China leads in publication volume, international collaborations, particularly those involving the U.S. and the EU, exhibit greater thematic diversity and innovation potential, suggesting that cross-border partnerships could accelerate advancements in this field. The findings point to a relatively narrow volume of literature in the numerical simulation of coal tar behavior, with only 13 identified studies applying the explicit term CFD. Moving forward, this study identifies three priority areas for future research: (i) Enhanced studies on legacy coal tar coatings in marine infrastructure, particularly their long-term ecological impacts; (ii) Development of sustainable alternatives to coal tar-based products aligned with circular economy principles; and (iii) Expansion of CFD and machine learning approaches to predict coal tar behavior under varying environmental and industrial conditions. By addressing these targeted research frontiers, the scientific community can better inform policy decisions, mitigate environmental and health risks, and optimize industrial processes involving tar-derived materials. This bibliometric analysis consolidates existing knowledge and charts a prospective roadmap for future research, bridging disciplinary divides and fostering sustainable innovation.

ABBREVIATIONS

CFD
Computational Fluid Dynamics
CTE
Coal Tar Enamel
PAH
Polycyclic Aromatic Hydrocarbon
PAHs
Polycyclic Aromatic Hydrocarbons
POPs
Persistent Organic Pollutants
SCP
Single Country Publication
MCP
Multiple Country Publication
EPA
Environmental Protection Agency
REACH
Registration, Evaluation, Authorization and Restriction of Chemicals
EU
European Union
GC-MS
Gas Chromatography-Mass Spectrometry
R
R Statistical Environment.

CONFLICT OF INTEREST

The authors declare that there is no conflict of interest.

REFERENCES

As published

Showing references and in-text citations exactly as published.

  1. 1.Aabbar, I.; Biache, C.; Cossu-Leguille, C.; Bojic, C.; Lorgeoux, C.; Masfaraud, J. F. et al. Effect of polycyclic aromatic compounds (PAH & Polar-PAC) availability on their ecotoxicity towards terrestrial organisms. Journal of Hazardous Materials. 2024;467:133646.GOOGLE SCHOLAR
  2. 2.Abdel-Shafy, H. I.; Mansour, M. S.. A review on polycyclic aromatic hydrocarbons: source, environmental impact, effect on human health and remediation. Egyptian journal of petroleum. 2016;25(1):107–123.GOOGLE SCHOLAR
  3. 3.Akinrinade, O. E.; Agunbiade, F. O.; Alani, R.; Ayejuyo, O. O.. Implementation of the Stockholm Convention on persistent organic pollutants (POPs) in Africa-progress, challenges, and recommendations after 20 years. Environmental Science: Advances. 2024;3(5):623–634.GOOGLE SCHOLAR
  4. 4.Anderson, T.. XIV.-On the constitution and properties of picoline, a new organic base from coal-tar. Earth and Environmental Science Transactions of The Royal Society of Edinburgh. 1846;16(2):123–136.GOOGLE SCHOLAR
  5. 5.Anderson, V.; Gough, W. A.. Enabling nature-based solutions to build back better—an environmental regulatory impact analysis of green infrastructure in Ontario, Canada. Buildings. 2022;12(1):61.GOOGLE SCHOLAR
  6. 6.Aria, M.; Cuccurullo, C.. bibliometrix: An R-tool for comprehensive science mapping analysis. Journal of informetrics. 2017;11(4):959–975.GOOGLE SCHOLAR
  7. 7.Balastegui, R.; Mansuy-Huault, L.; Lorgeoux, C.; Gauthier, C.; Gley, Renaud; Losson, B. et al. Impact of permanent dam opening on the fate of polycyclic aromatic compounds in industrial sludges accumulated on river banks: In situ approach. Science of the Total Environment. 2024;955:176879.GOOGLE SCHOLAR
  8. 8.Barbosa, F.; Rocha, B. A.; Souza, M. C.; Bocato, M. Z.; Azevedo, L. F. et al. Polycyclic aromatic hydrocarbons (PAHs): updated aspects of their determination, kinetics in the human body, and toxicity. Journal of Toxicology and Environmental Health, Part B. 2023;26(1):28–65.GOOGLE SCHOLAR
  9. 9.Boffetta, P.; Jourenkova, N.; Gustavsson, P.. Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons. Cancer Causes & Control. 1997;8(3):444–472.GOOGLE SCHOLAR
  10. 10.Bryer, P. J.; Elliott, J. N.; Willingham, E. J.. The effects of coal tar-based pavement sealer on amphibian development and metamorphosis. Ecotoxicology. 2006;15(3):241–247.GOOGLE SCHOLAR
  11. 11.Capobianco, N.; Basile, V.; Loia, F.; Vona, R.. End-of-life management of oil and gas offshore platforms: challenges and opportunities for sustainable decommissioning. Sinergie. 2022;40(2):299–326. https://doi.org/10.7433/S118.2022.14CrossrefGOOGLE SCHOLAR
  12. 12.CEP - CANADIAN ENVIRONMENTAL PROTECTION. Certain Products Containing Toxic Substances Regulations. Canada Gazette, Government of Canada, Part II. 2025;159(6).GOOGLE SCHOLAR
  13. 13.Chen, T.; Ku, X.; Li, T.; Karlsson, B. S.; Sjöblom, J.; Ström, H.. High-temperature pyrolysis modeling of a thermally thick biomass particle based on an MD-derived tar cracking model. Chemical Engineering Journal. 2021;417:127923.GOOGLE SCHOLAR
  14. 14.Chibwe, L.; Davie-Martin, C. L.; Aitken, M. D.; Hoh, E.; Simonich, S. L. M.. Identification of polar transformation products and high molecular weight polycyclic aromatic hydrocarbons (PAHs) in contaminated soil following bioremediation. Science of the Total Environment. 2017;599:1099–1107.GOOGLE SCHOLAR
  15. 15.Choi, H.; Nicolaescu, R.; Paek, S.; Ko, J.; Kamat, P. V.. Supersensitization of CdS quantum dots with a near-infrared organic dye: toward the design of panchromatic hybrid-sensitized solar cells. ACS nano. 2011;5(11):9238–9245.GOOGLE SCHOLAR
  16. 16.Coates, A. C.. Pipeline recoating - a cover up story. Pipeline Digest. 1991;28(7):11–12.GOOGLE SCHOLAR
  17. 17.Collins, J. F.; Brown, J. P.; Alexeeff, G. V.; Salmon, A. G.. Potency equivalency factors for some polycyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbon derivatives. Regulatory toxicology and pharmacology. 1998;28(1):45–54.GOOGLE SCHOLAR
  18. 18.Coulon, F.; Orsi, R.; Turner, C.; Walton, C.; Daly, P.; Pollard, S. J.. Understanding the fate and transport of petroleum hydrocarbons from coal tar within gasholders. Environment international. 2009;35(2):248–252.GOOGLE SCHOLAR
  19. 19.Dennis, R. V.; Fleer, N. A.; Davidson, R. D.; Banerjee, S.. Graphene Coatings for the Corrosion Protection of Base Metals. Graphene Technology: From Laboratory to Fabrication. 2016;155–176.GOOGLE SCHOLAR
  20. 20.Dennis, R. V.; Patil, V.; Andrews, J. L.; Aldinger, J. P.; Yadav, G. D.; Banerjee, S.. Hybrid nanostructured coatings for corrosion protection of base metals: a sustainability perspective. Materials Research Express. 2015;2(3):032001.GOOGLE SCHOLAR
  21. 21.Derviş, H.. Bibliometric analysis using bibliometrix an R package. Journal of scientometric research. 2019;8(3):156–160.GOOGLE SCHOLAR
  22. 22.EC, 2003. Commission Communication, COM. 644 final. Proposal for a regulation of the European Parliament and of the Council concerning the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH), establishing a European Chemicals Agency and amending Directive 1999/45/EC and Regulation (EC) {on Persistent Organic Pollutants} 29/10/2003. 2003.GOOGLE SCHOLAR
  23. 23.EPA - United States Environmental Protection Agency.. Coal Tar Sealcoat and PAHs. 2020.GOOGLE SCHOLAR
  24. 24.Feng, F.; Yang, Y.; Li, Z.; Song, J.; Zhu, H. et al. Changes in telomere length and telomerase activity in human bronchial epithelial cells induced by coal tar pitch extract. Toxicology Research. 2015;4(6):1535–1544.GOOGLE SCHOLAR
  25. 25.Francis, M.. Fate and decomposition of pipe coating materials in abandoned pipelines. Nov. Chem. Cent. Appl. Res. 2015.GOOGLE SCHOLAR
  26. 26.Gera, D.; Mathur, M.; Freeman, M.; O'DOWD, W. I. L. L. I. A. M.. Moisture and char reactivity modeling in pulverized coal combustors. Combustion science and technology. 2001;172(1):35–69.GOOGLE SCHOLAR
  27. 27.Ghosh, A.; Ghosh, B. B.; Basu, A. K.. Preliminary observations on acute toxicity of a coal-tar mill effluent, using copepod as test animal. Indian journal of experimental biology. 1974;12(2):203–204.GOOGLE SCHOLAR
  28. 28.Ghosh, U.; Zimmerman, J. R.; Luthy, R. G.. PCB and PAH speciation among particle types in contaminated harbor sediments and effects on PAH bioavailability. Environmental science & technology. 2003;37(10):2209–2217.GOOGLE SCHOLAR
  29. 29.Guo, F.; Li, X.; Liu, Y.; Peng, K.; Guo, C.; Rao, Z.. Catalytic cracking of biomass pyrolysis tar over char-supported catalysts. Energy conversion and management. 2018;167:81–90.GOOGLE SCHOLAR
  30. 30.He, X.; Li, R.; Qiu, J.; Xie, K.; Ling, P.; Yu, M. et al. Synthesis of mesoporous carbons for supercapacitors from coal tar pitch by coupling microwave-assisted KOH activation with a MgO template. Carbon. 2012;50(13):4911–4921.GOOGLE SCHOLAR
  31. 31.Huang, L.; Chernyak, S. M.; Batterman, S. A.. PAHs (polycyclic aromatic hydrocarbons), nitro-PAHs, and hopane and sterane biomarkers in sediments of southern Lake Michigan, USA. Science of the Total Environment. 2014;487:173–186.GOOGLE SCHOLAR
  32. 32.Husain, O. Al-Shamah; Abduljaleel, A.. Investigation of marine environmental related deterioration of coal tar epoxy paint on tubular steel pilings. Desalination. 2004;166(1-3):295–304. https://doi.org/10.1016/j.desal.2004.06.084CrossrefGOOGLE SCHOLAR
  33. 33.Isa, K. M.; Osman, K.; Abdullah, N. R.; Othman, N. F.; Hamid, M. N.. Gasifying agents type at lower temperature effect on bubbling fluidised bed gasification for low rank coal. Progress in Computational Fluid Dynamics, an International Journal. 2019;19(1):44–54.GOOGLE SCHOLAR
  34. 34.Jagtap, S. D.; Tambe, S. P.; Choudhari, R. N.; Mallik, B. P.. Mechanical and anticorrosive properties of non-toxic coal-tar epoxy alternative coating. Progress in Organic Coatings. 2014;77(2):395–402.GOOGLE SCHOLAR
  35. 35.Jongeneelen, F. J.; Anzion, R. B. M.; Henderson, P. T.. Determination of hydroxylated metabolites of polycyclic aromatic hydrocarbons in urine. Journal of Chromatography B: Biomedical Sciences and Applications. 1987;413:227–232.GOOGLE SCHOLAR
  36. 36.Kay, K.. A brief overview of the toxicological and epidemiological background to the detection and prevention of cancer in agricultural workers. Cancer Detection and Prevention. 1976;1(1):107.GOOGLE SCHOLAR
  37. 37.Kim, J. H.; Choi, Y. J.; Im, J. S.; Jo, A.; Lee, K. B.; Bai, B. C.. Study of activation mechanism for dual model pore structured carbon based on effects of molecular weight of petroleum pitch. Journal of Industrial and Engineering Chemistry. 2020;88:251–259.GOOGLE SCHOLAR
  38. 38.Kocan, R. M.; Matta, M. B.; Salazar, S. M.. Toxicity of weathered coal tar for shortnose sturgeon (Acipenser brevirostrum) embryos and larvae. Archives of Environmental Contamination and Toxicology. 1996;31(2):161–165.GOOGLE SCHOLAR
  39. 39.Koolen, H. H.; Swarthout, R. F.; Nelson, R. K.; Chen, H.; Krajewski, L. C. et al. Unprecedented insights into the chemical complexity of coal tar from comprehensive two-dimensional gas chromatography mass spectrometry and direct infusion fourier transform ion cyclotron resonance mass spectrometry. Energy & Fuels. 2015;29(2):641–648.GOOGLE SCHOLAR
  40. 40.Kumar, R.; Gupta, A.; Dhakate, S. R.. Nanoparticles-decorated coal tar pitch-based carbon foam with enhanced electromagnetic radiation absorption capability. RSC Advances. 2015;5(26):20256–20264.GOOGLE SCHOLAR
  41. 41.Lallas, P. L.. The Stockholm Convention on persistent organic pollutants. American Journal of International Law. 2001;95(3):692–708.GOOGLE SCHOLAR
  42. 42.LaVerne, J. A.; Kleemola, S. R.. Hydrogen production in the radiolysis of dodecane and hexane. Solvent Extraction and Ion Exchange. 2017;35(3):210–220.GOOGLE SCHOLAR
  43. 43.LaVerne, J. A.; Driscoll, M. S.; Al-Sheikhly, M.. Radiation stability of lignocellulosic material components. Radiation Physics and Chemistry. 2020;171:108716.GOOGLE SCHOLAR
  44. 44.Li, Z.; Wu, Y.; Zhao, Y.; Wang, L.; Zhu, H.; Qin, L. et al. Analysis of coal tar pitch and smoke extract components and their cytotoxicity on human bronchial epithelial cells. Journal of hazardous materials. 2011;186(2-3):1277–1282.GOOGLE SCHOLAR
  45. 45.Linak, W. P.; Yoo, J.-I.; Wasson, S. J.; Zhu, W.; Wendt, J. O. L. et al. Ultrafine ash aerosols from coal combustion: Characterization and health effects. Proceedings of the Combustion Institute. 2007;31(2):1929–1937.GOOGLE SCHOLAR
  46. 46.Linchtenstein, J.. Effectiveness of pipeline coatings for corrosion control. Mater. Perform. 2003;42:74–75.GOOGLE SCHOLAR
  47. 47.Lisovskaya, A.; Bartels, D. M.. Reduction of CO2 by hydrated electrons in high temperature water. Radiation Physics and Chemistry. 2019;158:61–63.GOOGLE SCHOLAR
  48. 48.Long, A. S.; Lemieux, C. L.; Gagne, R.; Lambert, I. B.; White, P. A.. Genetic toxicity of complex mixtures of polycyclic aromatic hydrocarbons: evaluating dose-additivity in a transgenic mouse model. Environmental science & technology. 2017;51(14):8138–8148.GOOGLE SCHOLAR
  49. 49.Mahler, B. J.; Metre, P. C. V.; Crane, J. L.; Watts, A. W.; Scoggins, M.; Williams, E. S.. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management. Environmental science & technology. 2012;46(6):3039–3045.GOOGLE SCHOLAR
  50. 50.Marvin, C. H.; Lundrigan, J. A.; McCarry, B. E.; Bryant, D. W.. Determination and genotoxicity of high molecular mass polycyclic aromatic hydrocarbons isolated from coal‐tar‐contaminated sediment. Environmental Toxicology and Chemistry: An International Journal. 1995;14(12):2059–2066.GOOGLE SCHOLAR
  51. 51.McIntyre, J. K.; Edmunds, R. C.; Anulacion, B. F.; Davis, J. W.; Incardona, J. P. et al. Severe coal tar sealcoat runoff toxicity to fish is prevented by bioretention filtration. Environmental Science & Technology. 2016;50(3):1570–1578.GOOGLE SCHOLAR
  52. 52.Merten, B. J.. Corrosion Protection of steel structures by coal tar enamel: 80 years of performance. Report number ST-2017-1546-01 and 2017-8540-45. 2017.GOOGLE SCHOLAR
  53. 53.Mueller, J. G.; Chapman, P. J.; Pritchard, P. H.. Creosote-contaminated sites. Their potential for bioremediation. Environmental science & technology. 1989;23(10):1197–1201.GOOGLE SCHOLAR
  54. 54.Mueller, J. G.; Middaugh, D. P.; Lantz, S. E.; Chapman, P. J.. Biodegradation of creosote and pentachlorophenol in contaminated groundwater: chemical and biological assessment. Applied and Environmental Microbiology. 1991;57(5):1277–1285.GOOGLE SCHOLAR
  55. 55.Needleman, H.. The Use, Impact, and Ban of Coal Tar-Based Sealants. 2015.GOOGLE SCHOLAR
  56. 56.Neff, J. M.; Stout, S. A.; Gunster, D. G.. Ecological risk assessment of polycyclic aromatic hydrocarbons in sediments: identifying sources and ecological hazard. Integrated environmental assessment and management. 2005;1(1):22–33.GOOGLE SCHOLAR
  57. 57.Niemeier, R. W.. Petroleum, coal tar, and related products. Patty's toxicology. 2001;325–370.GOOGLE SCHOLAR
  58. 58.Oziolor, E. M.; Bigorgne, E.; Aguilar, L.; Usenko, S.; Matson, C. W.. Evolved resistance to PCB-and PAH-induced cardiac teratogenesis, and reduced CYP1A activity in Gulf killifish (Fundulus grandis) populations from the Houston Ship Channel, Texas. Aquatic Toxicology. 2014;150:210–219.GOOGLE SCHOLAR
  59. 59.Perianes-Rodriguez, A.; Waltman, L.; Van Eck, N. J.. Constructing bibliometric networks: A comparison between full and fractional counting. Journal of informetrics. 2016;10(4):1178–1195.GOOGLE SCHOLAR
  60. 60.Rezapour, M.; Deymi-Dashtebayaz, M.. Numerical and optimization modeling of dual-fuel natural gas-diesel engine at the idle load. Journal of Thermal Analysis and Calorimetry. 2024;149(21):11913–11928.GOOGLE SCHOLAR
  61. 61.Rocha, V. G.; Menéndez, R.; Santamaría, R.; Blanco, C.; Granda, M.. Oxidation behaviour of magnesia-carbon materials prepared with petroleum pitch as binder. Journal of Analytical and Applied Pyrolysis. 2010;88(2):207–212.GOOGLE SCHOLAR
  62. 62.Russo, C.; Ciajolo, A.; Stanzione, F.; Tregrossi, A.; Oliano, M. M. et al. Investigation on chemical and structural properties of coal-and petroleum-derived pitches and implications on physico-chemical properties (solubility, softening and coking). Fuel. 2019;245:478–487.GOOGLE SCHOLAR
  63. 63.Seo, I.; Jeon, R.; Yoon, T. U.; Lee, C. H.. Optimization of cleaning process in semiconductor gas delivery system by computational fluid dynamics simulation. Process Safety and Environmental Protection. 2024;191:505–522.GOOGLE SCHOLAR
  64. 64.Serednitskii, Y. A.; Mindyuk, A. K.; Tselyukh, O. I.; Suprun, V. V.; Dzikovskii, O. M.; Dombrovskii, B. O.. Increasing the protective characteristics of bituminous coatings by modification with corrosion inhibitors. Soviet materials science: a transl. of Fiziko-khimicheskaya mekhanika materialov/Academy of Sciences of the Ukrainian SSR. 1987;22(6):625–628.GOOGLE SCHOLAR
  65. 65.Shi, W.; Gong, H.; Zhou, W.; Tan, X.; Zhang, C.; Dai, X.. Distribution and ecological risk of polycyclic aromatic hydrocarbons in wastewater treatment plant sludge and sewer sediment from cities in Middle and Lower Yangtze River. Science of The Total Environment. 2023;881:163212.GOOGLE SCHOLAR
  66. 66.Simpson, S. L.; Spadaro, D. A.; Batley, G. E.; Irvine, I. A.; Synnot, R. N.. Remediation criteria for gasworks-impacted sediments: Assessing the effects of legacy hydrocarbons and more recent metal contamination. Science of the Total Environment. 2020;737:139725.GOOGLE SCHOLAR
  67. 67.Singh, R.; Marchant, P.; Golczynski, S.. Modeling and optimizing gas solid distribution in fluidized beds. Powder Technology. 2024;446:120145.GOOGLE SCHOLAR
  68. 68.Smith, M. J.; Flowers, T. H.; Duncan, H. J.; Alder, J.. Effects of polycyclic aromatic hydrocarbons on germination and subsequent growth of grasses and legumes in freshly contaminated soil and soil with aged PAHs residues. Environmental pollution. 2006;141(3):519–525.GOOGLE SCHOLAR
  69. 69.Sofowote, U. M.; McCarry, B. E.; Marvin, C. H.. Source apportionment of PAH in Hamilton Harbour suspended sediments: comparison of two factor analysis methods. Environmental science & technology. 2008;42(16):6007–6014.GOOGLE SCHOLAR
  70. 70.Stout, S. A.; Brey, A. P.. Appraisal of coal-and coke-derived wastes in soils near a former manufactured gas plant, Jacksonville, Florida. International Journal of Coal Geology. 2019;213:103265.GOOGLE SCHOLAR
  71. 71.Sweileh, W. M.; AbuTaha, A. S.; Sawalha, A. F.; Al-Khalil, S.; Al-Jabi, S. W.; Zyoud, S. E. H.. Bibliometric analysis of worldwide publications on multi-, extensively, and totally drug-resistant tuberculosis (2006-2015). Multidisciplinary Respiratory Medicine. 2016;11:1–16.GOOGLE SCHOLAR
  72. 72.Tarábek, P.; Liu, S.; Haygarth, K.; Bartels, D. M.. Hydrogen gas yields in irradiated room-temperature ionic liquids. Radiation Physics and Chemistry. 2009;78(3):168–172.GOOGLE SCHOLAR
  73. 73.Temel, B.; Sakar, C.; Buber, M.. Fuzzy bow-tie analysis for mitigating self-heating risks in maritime coal transportation. Marine Pollution Bulletin. 2024;Volume 209. https://doi.org/10.1016/j.marpolbul.2024.117122CrossrefGOOGLE SCHOLAR
  74. 74.Van Eck, N. J.; Waltman, L.. Visualizing bibliometric networks. In Measuring scholarly impact: Methods and practice. Cham: Springer International Publishing. 2014;285–320.GOOGLE SCHOLAR
  75. 75.Van Metre, P. C.; Mahler, B.; Scoggins, M.; Hamilton, P. A.. Parking lot sealcoat: A major source of polycyclic aromatic hydrocarbons (PAHs). in urban and suburban environments (No. 2005-3147). US Geological Survey. 2005.GOOGLE SCHOLAR
  76. 76.Vasconcelos, R. N.; Lima, A. T. C.; Lentini, C. a. D.; Miranda, G. V.; Mendonça, L. F.; Silva, M. A. et al. Oil spill detection and mapping: A 50-year bibliometric analysis. Remote Sensing. 2020;12(21):3647.GOOGLE SCHOLAR
  77. 77.Vasconcelos, R. N.; Lima, A. T. C.; Lentini, C. A. D.; Miranda, J. G. V.; de Mendonça, L. F. F.; Lopes, J. M. et al. Deep learning-based approaches for oil spill detection: A bibliometric review of research trends and challenges. Journal of Marine Science and Engineering. 2023;11(7):1406.GOOGLE SCHOLAR
  78. 78.Velazquez, J. C.; Valor, A.; Caleyo, F.; Venegas, V.; Espina-Hernandez, J. H.; Hallen, J. M.. Pitting corrosion models improve integrity management, reliability. Oil & gas journal. 2009;107(28).GOOGLE SCHOLAR
  79. 79.Vidya, P.; Desai, S. R. P.; Ussuf, K. K.. Biodegradation of polycyclic aromatic hydrocarbons by Phanerochaete chrysosporium. 2004.GOOGLE SCHOLAR
  80. 80.Vijayanand, M.; Ramakrishnan, A.; Subramanian, R.; Issac, P. K.; Nasr, M.; Khoo, K. S. et al. Polyaromatic hydrocarbons (PAHs) in the water environment: A review on toxicity, microbial biodegradation, systematic biological advancements, and environmental fate. Environmental research. 2023;227:115716.GOOGLE SCHOLAR
  81. 81.Wang, H.. Tobacco control in China: the dilemma between economic development and health improvement. Salud publica de Mexico. 2006;48:s140–s147.GOOGLE SCHOLAR
  82. 82.Wang, P.; Grdanovska, S.; Bartels, D. M.; Was, G. S.. Effect of radiation damage and water radiolysis on corrosion of FeCrAl alloys in hydrogenated water. Journal of Nuclear Materials. 2020;533:152108.GOOGLE SCHOLAR
  83. 83.Wang, Y. G.; Jiang, W. J.; Shen, J.; Wang, W.; Niu, Y. X.; Zhao, W. et al. Detoxification modification of coal-tar pitch by ultraviolet & microwave radiation-enhanced chemical reaction and toxicity evaluation by chemical index and cytotoxicity assay in vitro. Journal of hazardous materials. 2021;410:124648.GOOGLE SCHOLAR
  84. 84.Wise, S. A.; Benner, B. A.; Byrd, G. D.; Chesler, S. N.; Rebbert, R. E.; Schantz, M. M.. Determination of polycyclic aromatic hydrocarbons in a coal tar standard reference material. Analytical Chemistry. 1988;60(9):887–894.GOOGLE SCHOLAR
  85. 85.Wu, Z.; Lin, T.; Hu, L.; Guo, T.; Guo, Z.. Polycyclic aromatic hydrocarbons in sediment-porewater system from the East China Sea: Occurrence, partitioning, and diffusion. Environmental research. 2022;209:112755.GOOGLE SCHOLAR
  86. 86.Xu, W.; Wang, X.; Cai, Z.. Analytical chemistry of the persistent organic pollutants identified in the Stockholm Convention: A review. Analytica Chimica Acta. 2013;790:1–13.GOOGLE SCHOLAR
  87. 87.Yang, Z.; Shah, K.; Crevier, C.; Laforest, S.; Lambert, P. et al. Occurrence, source and ecological assessment of petroleum related hydrocarbons in intertidal marine sediments of the Bay of Fundy, New Brunswick, Canada. Marine Pollution Bulletin. 2018;133:799–807.GOOGLE SCHOLAR
  88. 88.Yin, K.; Yang, Y.; Cheng, Y. F.. Permeability of coal tar enamel coating to cathodic protection current on pipelines. Construction and Building Materials. 2018;192:20–27.GOOGLE SCHOLAR
  89. 89.Yun, L.; Yuan, X.; Zhen, Z.; Rui, W.; Rongsheng, Z.; Qiang, F.. Study on cavitation flow and high-speed vortex interference mechanism of high-speed inducer centrifugal pump based on full flow channel. Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2024;46(12):1–19.GOOGLE SCHOLAR
  90. 90.Zeng, D.; Hu, S.; Sayre, A. N.; Sarv, H.. On the rank-dependence of coal tar secondary reactions. Proceedings of the Combustion Institute. 2011;33(2):1707–1714.GOOGLE SCHOLAR

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Cruz, M. M. D., David, D. D., Vannuci-Silva, M., Lopes, J. M., Parente, C. E. T., Thalhofer, J. L., Filgueiras, R., Lima, I. C. B., Lima, A. T. D. C., Lentini, C. A. D., Mendonça, L. F. F. D., Salomon, P. S., & Silva, A. X. D. (2026). Research Trends on Coal Tar in Infrastructure Decommissioning: A Systematic Review Revealing Scientific Performance and Knowledge Gaps. Journal of Scientometric Research, 15(3), 1107–1119. https://doi.org/10.5530/jscires.20260203